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Property:Nominal Voltage | Open Energy Information
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Nominal Voltage Nominal Voltage Jump to: navigation, search Property Name Nominal Voltage Property Type Number This is a property of type Number. Pages using the property "Nominal Voltage" Showing 22 pages using this property. D Distributed Generation Study/10 West 66th Street Corp + 480 + Distributed Generation Study/615 kW Waukesha Packaged System + 480 + Distributed Generation Study/Aisin Seiki G60 at Hooligans Bar and Grille + 240 + Distributed Generation Study/Arrow Linen + 480 + Distributed Generation Study/Dakota Station (Minnegasco) + 0 + Distributed Generation Study/Elgin Community College + 4,160 + Distributed Generation Study/Emerling Farm + 480 + Distributed Generation Study/Floyd Bennett + 480 + Distributed Generation Study/Harbec Plastics + 480 +
Mitigation of different type voltage sags in low voltage distribution systems using dynamic voltage restorer
Science Conference Proceedings (OSTI)
The main problems of the voltage sag in low voltage distribution systems due to sensitive loads. Voltage sags can caused malfunction in the distribution system. In order to protect voltage sags in the network a device which called Dynamic Voltage Restorer ... Keywords: custom device, dynamic voltage restorer (DVR), low voltage, power injected, voltage sag
Rosli Omar
Voltage balanced multilevel voltage source converter system
SciTech Connect
A voltage balanced multilevel converter for high power AC applications such as adjustable speed motor drives and back-to-back DC intertie of adjacent power systems. This converter provides a multilevel rectifier, a multilevel inverter, and a DC link between the rectifier and the inverter allowing voltage balancing between each of the voltage levels within the multilevel converter. The rectifier is equipped with at least one phase leg and a source input node for each of the phases. The rectifier is further equipped with a plurality of rectifier DC output nodes. The inverter is equipped with at least one phase leg and a load output node for each of the phases. The inverter is further equipped with a plurality of inverter DC input nodes. The DC link is equipped with a plurality of rectifier charging means and a plurality of inverter discharging means. The plurality of rectifier charging means are connected in series with one of the rectifier charging means disposed between and connected in an operable relationship with each adjacent pair of rectifier DC output nodes. The plurality of inverter discharging means are connected in series with one of the inverter discharging means disposed between and connected in an operable relationship with each adjacent pair of inverter DC input nodes. Each of said rectifier DC output nodes are individually electrically connected to the respective inverter DC input nodes. By this means, each of the rectifier DC output nodes and each of the inverter DC input nodes are voltage balanced by the respective charging and discharging of the rectifier charging means and the inverter discharging means.
Peng, Fang Zheng (Oak Ridge, TN); Lai, Jih-Sheng (Knoxville, TN)
Disclosed is a voltage balanced multilevel converter for high power AC applications such as adjustable speed motor drives and back-to-back DC intertie of adjacent power systems. This converter provides a multilevel rectifier, a multilevel inverter, and a DC link between the rectifier and the inverter allowing voltage balancing between each of the voltage levels within the multilevel converter. The rectifier is equipped with at least one phase leg and a source input node for each of the phases. The rectifier is further equipped with a plurality of rectifier DC output nodes. The inverter is equipped with at least one phase leg and a load output node for each of the phases. The inverter is further equipped with a plurality of inverter DC input nodes. The DC link is equipped with a plurality of rectifier charging means and a plurality of inverter discharging means. The plurality of rectifier charging means are connected in series with one of the rectifier charging means disposed between and connected in an operable relationship with each adjacent pair of rectifier DC output nodes. The plurality of inverter discharging means are connected in series with one of the inverter discharging means disposed between and connected in an operable relationship with each adjacent pair of inverter DC input nodes. Each of said rectifier DC output nodes are individually electrically connected to the respective inverter DC input nodes. By this means, each of the rectifier DC output nodes and each of the inverter DC input nodes are voltage balanced by the respective charging and discharging of the rectifier charging means and the inverter discharging means. 15 figs.
Peng, F.Z.; Lai, J.S.
Characterisation of the VELO High Voltage System
E-Print Network (OSTI)
The high voltage system supplies the bias voltage to the 88 silicon sensors which comprise the LHCb Vertex Locator (VELO). This note describes the results of the tests which have been performed on the hardware of the high voltage system of the VELO. Each individual test detailed in this note corresponds to a specific requirement of the system. These requirements arise primarily from ensuring the safety of the silicon sensors and the quality of the data taken from the VELO modules. The tests performed are in four categories: normal operation of the high voltage system; verification of its stability under operation; discussion of its behaviour in failure modes; and details of operation at low voltage. Noteworthy issues, identified through the tests, include the behaviour of the high voltage modules at voltages below 9V, the current limit that can be applied during ramping of the voltage, and the speed with which the voltage is cut during failures of the system. The results of these tests provide high confidence that the high voltage system can be safely used and demonstrate that low noise is produced by the power supplies. LHCb Public Note, LHCb-2008-009Contents 1
Barinjaka Rakotomiaramanana; Chris Parkes; Lars Eklund
Nominal rewriting
Nominal rewriting is based on the observation that if we add support for @a-equivalence to first-order syntax using the nominal-set approach, then systems with binding, including higher-order reduction schemes such as @l-calculus beta-reduction, can ... Keywords: ?-Conversion, Binders, Confluence, First and higher-order rewriting
Maribel Fern�ndez; Murdoch J. Gabbay
The high voltage system supplies the bias voltage to the 88 silicon sensors which comprise the LHCb Vertex Locator (VELO). This note describes the results of the tests which have been performed on the hardware of the high voltage system of the VELO. Each individual test detailed in this note corresponds to a specific requirement of the system. These requirements arise primarily from ensuring the safety of the silicon sensors and the quality of the data taken from the VELO modules. The tests performed are in four categories: normal operation of the high voltage system; vercation of its stability under operation; discussion of its behaviour in failure modes; and details of operation at low voltage. Noteworthy issues, identified through the tests, include the behaviour of the high voltage modules at voltages below 9V, the current limit that can be applied during ramping of the voltage, and the speed with which the voltage is cut during failures of the system. The results of these tests provide high confidence th...
Rakotomiaramanana, B; Eklund, L
The high voltage system supplies the bias voltage to the 88 silicon sensors which comprise the LHCb Vertex Locator (VELO). This note describes the results of the tests which have been performed on the hardware of the high voltage system of the VELO. Each individual test detailed in this note corresponds to a specific requirement of the system. These requirements arise primarily from ensuring the safety of the silicon sensors and the quality of the data taken from the VELO modules. The tests performed are in four categories: normal operation of the high voltage system; verification of its stability under operation; discussion of its behaviour in failure modes; and details of operation at low voltage. Noteworthy issues, identified through the tests, include the behaviour of the high voltage modules at voltages below 9V, the current limit that can be applied during ramping of the voltage, and the speed with which the voltage is cut during failures of the system. The results of these tests provide high confidence...
Nominal Position Controller for Permanent Magnet Synchronous Motor System
A nonlinear position controller for permanent magnet synchronous motor (PMSM) was designed to achieve position tracing control and robust control. The controller included two parts: the model controller and the robust controller. The former was designed ... Keywords: PMSM, nominal control, sliding mode control
Yuzeng Zhang; Fan Wang; Mingyin Yan
Performance of Dynamic Voltage Restorer (DVR) against Voltage Sags and Swells Using Space Vector PWM Technique
Due to increasing complexity in the power system, voltage sags are now becoming one of the most significant power quality problems. Voltage sag is a short reduction voltage from nominal voltage, occurs in a short time. Short-lived voltage sags may not ... Keywords: Custom power, power quality, voltage sag, SPWM, SVPWM, DVR, PSCAD/EMTDC.
Palaparthi Ananthababu; Burle Trinadha; K. Ram Charan
Green Island Power Authority Transmission Voltage Support System...
Energy.gov (U.S. Department of Energy (DOE)) Indexed Site
Green Island Power Authority Transmission Voltage Support System Project Green Island Power Authority Transmission Voltage Support System Project Power point presentation...
Electrical system architecture having high voltage bus
DOE Patents (OSTI)
An electrical system architecture is disclosed. The architecture has a power source configured to generate a first power, and a first bus configured to receive the first power from the power source. The architecture also has a converter configured to receive the first power from the first bus and convert the first power to a second power, wherein a voltage of the second power is greater than a voltage of the first power, and a second bus configured to receive the second power from the converter. The architecture further has a power storage device configured to receive the second power from the second bus and deliver the second power to the second bus, a propulsion motor configured to receive the second power from the second bus, and an accessory motor configured to receive the second power from the second bus.
Hoff, Brian Douglas (East Peoria, IL); Akasam, Sivaprasad (Peoria, IL)
A Novel Dynamic Voltage Restorer with Outage Handling Capability Using Fuzzy Logic Controler
This paper presents a novel dynamic voltage restorer (DVR) capable of handling deep sags including outage on a low voltage distribution system. The DVR recovers sags up to 10% of nominal voltage; otherwise, it will operate as an uninterruptible power ...
M. Ashari; T. Hiyama; M. Pujiantara; H. Suryoatmojo; M. Hery Purnomo
Quantum Voltage System Development and Dissemination
... of the unit of electric potential difference, the volt, and precise techniques for measuring voltage are essential to the electrical ... Facilities/Tools Used: ...
Local Dynamic Reactive Power for Correction of System Voltage Problems
Distribution systems are experiencing outages due to a phenomenon known as local voltage collapse. Local voltage collapse is occurring in part because modern air conditioner compressor motors are much more susceptible to stalling during a voltage dip than older motors. These motors can stall in less than 3 cycles (.05s) when a fault, such as on the sub-transmission system, causes voltage to sag to 70 to 60%. The reasons for this susceptibility are discussed in the report. During the local voltage collapse, voltages are depressed for a period of perhaps one or two minutes. There is a concern that these local events are interacting together over larger areas and may present a challenge to system reliability. An effective method of preventing local voltage collapse is the use of voltage regulation from Distributed Energy Resources (DER) that can supply or absorb reactive power. DER, when properly controlled, can provide a rapid correction to voltage dips and prevent motor stall. This report discusses the phenomenon and causes of local voltage collapse as well as the control methodology we have developed to counter voltage sag. The problem is growing because of the use of low inertia, high efficiency air conditioner (A/C) compressor motors and because the use of electric A/C is growing in use and becoming a larger percentage of system load. A method for local dynamic voltage regulation is discussed which uses reactive power injection or absorption from local DER. This method is independent, rapid, and will not interfere with conventional utility system voltage control. The results of simulations of this method are provided. The method has also been tested at the ORNL s Distributed Energy Communications and Control (DECC) Laboratory using our research inverter and synchronous condenser. These systems at the DECC Lab are interconnected to an actual distribution system, the ORNL distribution system, which is fed from TVA s 161kV sub-transmission backbone. The test results are also provided and discussed. The simulations and testing show that local voltage control from DER can prevent local voltage collapse. The results also show that the control can be provided so quickly, within 0.5 seconds, that is does not interfere with conventional utility methods.
Kueck, John D [ORNL; Rizy, D Tom [ORNL; Li, Fangxing [ORNL; Xu, Yan [ORNL; Li, Huijuan [University of Tennessee, Knoxville (UTK); Adhikari, Sarina [ORNL; Irminger, Philip [ORNL
Optical control system for high-voltage terminals
An optical control system for the control of devices in the terminal of an electrostatic accelerator includes a laser that is modulated by a series of preselected codes produced by an encoder. A photodiode receiver is placed in the laser beam at the high-voltage terminal of an electrostatic accelerator. A decoder connected to the photodiode decodes the signals to provide control impulses for a plurality of devices at the high voltage of the terminal.
Bicek, John J. (Tinley Park, IL)
Voltage stability limits for weak power systems with high wind penetration.
??Analysis of power system voltage stability has practical value in increasing wind penetration levels. As wind penetration levels increase in power systems, voltage stability challenges� (more)
Tamimi, Ala
Smart Solar Home System with Safety Device Low Voltage Alert
For many reasons Bangladeshi people are now using renewable energy. So, solar energy is the best renewable energy till now, in respect of Bangladesh. So using of solar system is common nowadays. Bangladesh Government has taken some steps to make solar ... Keywords: Smart Solar Home System (SSHS), Rooftop, Safety Device, Low voltage alert
Tawheed Hasan; Md. Faysal Nayan; Md. Asif Iqbal; Monzurul Islam
A variable voltage MPPT control method for photovoltaic generation system
To increase the output efficiency of a photovoltaic (PV) generation system it is important to have an efficient maximum power point tracking (MPPT) technique. This paper describes the analysis, design and implementation of an efficient tracking method ... Keywords: maximum power point tracking (MPPT), photovoltaic generation system, pulse-width-modulation (PWM), solar energy, variable voltage
Liu Liqun; Wang Zhixin
Requirements for a Standard Test to Rate the Durability of PV Modules at System Voltage (Presentation)
DOE Green Energy (OSTI)
Degradation modes in photovoltaic modules under system bias voltage stress are described and classified.
Hacke, P.; Terwilliger, K.; Glick, S.; Kempe, M.; Kurtz, S.; Bennett, I.; Kloos, M.
Analysis on DFIG Wind Power System Low-Voltage Ridethrough
Due to the double fed induction generator�s (DFIG) advantage of controlling active and reactive power independently and partial power converter, DFIG is becoming a popular type of wind power generation system. Nowadays, the grid code demands that ... Keywords: VSCF, DFIG, LVRT, Crowbar, Voltage sags
Yulong Wang; Jianlin Li; Shuju Hu; Honghua Xu
High-Voltage Power Supply System for Laser Isotope Separation
This report presents several concepts for Laser High-Voltage Power Supply (HVPS) Systems for a Laser Isotope Separation facility. Selection of equipments and their arrangement into operational systems is based on proven designs and on application concepts now being developed. This report has identified a number of alternative system arrangements and has provided preliminary cost estimates for each. The report includes a recommendation for follow-on studies that will further define the optimum Laser HVPS Systems. Brief descriptions are given of Modulator/Regulator circuit trade-offs, system control interfaces, and their impact on costs.
Ketaily, E.C.; Buckner, R.P.; Uhrik, R.L.
Blocking diodes and fuses in low-voltage PV systems
Instructions and labels supplied with listed PV modules and the requirements of the National Electrical Code (NEC) dictate that a series fuse shall be used to protect the module against backfeed currents. Few of the hundreds of thousands of low-voltage (12, 24, and 48-volt) stand-alone photovoltaic (PV) power systems use series fuses on each module or string of modules. Tests and simulations at the Southwest Technology Development Institute (TDI) and at Sandia National Laboratories (SNL) have established that the absence of these fuses can pose significant fire and safety hazards even on 12-volt PV systems. If the system has sufficient backfeed voltage and current, it is possible that a ground fault in the wiring or inside a module can result in the destruction of a PV module.
Wiles, J.C. [New Mexico State Univ., Las Cruces, NM (United States). Southwest Technology Development Inst.; King, D.L. [Sandia National Labs., Albuquerque, NM (United States). Photovoltaic Systems R and D
System for increasing corona inception voltage of insulating oils
The Corona Inception Voltage of insulating oils is increased by repetitive cycles of prestressing the oil with a voltage greater than the corona inception voltage, and either simultaneously or serially removing byproducts of corona by evacuation and heating the oil.
Rohwein, Gerald J. (Albuquerque, NM)
An accurate continuous calibration system for high voltage current transformer
A continuous calibration system for high voltage current transformers is presented in this paper. The sensor of this system is based on a kind of electronic instrument current transformer, which is a clamp-shape air core coil. This system uses an optical fiber transmission system for its signal transmission and power supply. Finally the digital integrator and fourth-order convolution window algorithm as error calculation methods are realized by the virtual instrument with a personal computer. It is found that this system can calibrate a high voltage current transformer while energized, which means avoiding a long calibrating period in the power system and the loss of power metering expense. At the same time, it has a wide dynamic range and frequency band, and it can achieve a high accuracy measurement in a complex electromagnetic field environment. The experimental results and the on-site operation results presented in the last part of the paper, prove that it can reach the 0.05 accuracy class and is easy to operate on site.
Tong Yue; Li Binhong [College of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, Hubei Province (China)
Distribution System Voltage Performance Analysis for High-Penetration Photovoltaics
This report examines the performance of commonly used distribution voltage regulation methods under reverse power flow.
Liu, E.; Bebic, J.
Commercialization of Medium Voltage HTS Triax TM Cable Systems
The original project scope that was established in 2007 aimed to install a 1,700 meter (1.1 mile) medium voltage HTS Triax{TM} cable system into the utility grid in New Orleans, LA. In 2010, however, the utility partner withdrew from the project, so the 1,700 meter cable installation was cancelled and the scope of work was reduced. The work then concentrated on the specific barriers to commercialization of HTS cable technology. The modified scope included long-length HTS cable design and testing, high voltage factory test development, optimized cooling system development, and HTS cable life-cycle analysis. In 2012, Southwire again analyzed the market for HTS cables and deemed the near term market acceptance to be low. The scope of work was further reduced to the completion of tasks already started and to testing of the existing HTS cable system in Columbus, OH. The work completed under the project included: � Long-length cable modeling and analysis � HTS wire evaluation and testing � Cable testing for AC losses � Optimized cooling system design � Life cycle testing of the HTS cable in Columbus, OH � Project management. The 200 meter long HTS Triax{TM} cable in Columbus, OH was incorporated into the project under the initial scope changes as a test bed for life cycle testing as well as the site for an optimized HTS cable cooling system. The Columbus cable utilizes the HTS TriaxTM design, so it provided an economical tool for these of the project tasks.
Knoll, David
Satellite power system (SPS). Rectenna siting: availability and distribution of nominally eligible sites
Siting of 60 ground receiving stations (rectennas) for the SPS may pose a problem due to the large area per rectenna (15,000 hectares, 38,000 acres) and numerous siting constraints. This study analyzes areas potentially eligible for rectenna sites by mapping, at a national scale, those conditions which would preclude rectenna construction. These exclusion variables which reflect restricted lands, topography, safety, national policy and electromagnetic (microwave) effects, have been computer encoded and tabulated. Subsequent analysis of the nine electric power planning regions that make up the contiguous states indicate an apparently adequate number of nominally eligible sites in all regions in comparison to projected electrical generation. Eligibility in this context means only that areas were not excluded in this national level analysis; more detailed investigation may reveal purely local constraints or smaller scale exclusions. A second major qualification relates to small isolated eligible areas. Eliminating individual eligible clusters with less than nine times the area of one rectenna eliminates much of the Eastern US; a four-to-one adjacent eligible area test poses no such problem. An independant study of the placement of 60 nominal sites in relation to projected load centers reveals that, even with modest transmission distances, the supply of eligible areas is not a key constraint, except perhaps in the Mid-Atlantic (Electric Reliability) Council Region. Even when several less critical (potential) exclusions are considered, more than 19% of the US is eligible; every region except Mid-Atlantic has at least 50 times an many eligible sites as are required.
Not Available
Voltage control of emerging distribution systems with induction motor loads using robust LQG approach
mode" in emerging distribution systems. The small-signal stability analysis indicates that load voltageVoltage control of emerging distribution systems with induction motor loads using robust LQG has significant performance to improve the voltage profile of the distributed generation system
Pota, Himanshu Roy
Bi-directional power control system for voltage converter
A control system for a voltage converter includes: a power comparator for comparing a power signal on input terminals of the converter with a commanded power signal and producing a power comparison signal; a power regulator for transforming the power comparison signal to a commanded current signal; a current comparator for comparing the commanded current signal with a measured current signal on output terminals of the converter and producing a current comparison signal; a current regulator for transforming the current comparison signal to a pulse width modulator (PWM) duty cycle command signal; and a PWM for using the PWM duty cycle command signal to control electrical switches of the converter. The control system may further include: a command multiplier for converting a voltage signal across the output terminals of the converter to a gain signal having a value between zero (0) and unity (1), and a power multiplier for multiplying the commanded power signal by the gain signal to provide a limited commanded power signal, wherein power comparator compares the limited commanded power signal with the power signal on the input terminals.
Garrigan, Neil Richard (Niskayuna, NY); King, Robert Dean (Schenectady, NY); Schwartz, James Edward (Slingerlands, NY)
A control system for a voltage converter includes: a power comparator for comparing a power signal on input terminals of the converter with a commanded power signal and producing a power comparison signal; a power regulator for transforming the power comparison signal to a commanded current signal; a current comparator for comparing the commanded current signal with a measured current signal on output terminals of the converter and producing a current comparison signal; a current regulator for transforming the current comparison signal to a pulse width modulator (PWM) duty cycle command signal; and a PWM for using the PWM duty cycle command signal to control electrical switches of the converter. The control system may further include: a command multiplier for converting a voltage signal across the output terminals of the converter to a gain signal having a value between zero (0) and unity (1), and a power multiplier for multiplying the commanded power signal by the gain signal to provide a limited commanded power signal, wherein power comparator compares the limited commanded power signal with the power signal on the input terminals. 10 figs.
Garrigan, N.R.; King, R.D.; Schwartz, J.E.
The Corona Inception Voltage of insulating oils is increased by repetitive cycles of prestressing the oil with a voltage greater than the corona inception voltage, and either simultaneously or serially removing byproducts of corona by evacuation and heating the oil. 5 figs.
Rohwein, G.J.
Intelligent robust control of hybrid distributed generation system under voltage sag
In this paper, design of control strategy for hybrid fuel cell/energy storage distributed power generation system during voltage sag has been presented. The proposed control strategy allows hybrid distributed generation system works properly when a voltage ... Keywords: Energy storage, Fuel cell, Fuzzy sliding control, Hybrid distributed generation, Lyapanov, Neuro-fuzzy, Voltage sag
Amin Hajizadeh; Masoud Aliakbar Golkar
System and method for floating-substrate passive voltage contrast
A passive voltage contrast (PVC) system and method are disclosed for analyzing ICs to locate defects and failure mechanisms. During analysis a device side of a semiconductor die containing the IC is maintained in an electrically-floating condition without any ground electrical connection while a charged particle beam is scanned over the device side. Secondary particle emission from the device side of the IC is detected to form an image of device features, including electrical vias connected to transistor gates or to other structures in the IC. A difference in image contrast allows the defects or failure mechanisms be pinpointed. Varying the scan rate can, in some instances, produce an image reversal to facilitate precisely locating the defects or failure mechanisms in the IC. The system and method are useful for failure analysis of ICs formed on substrates (e.g. bulk semiconductor substrates and SOI substrates) and other types of structures.
Jenkins, Mark W. (Albuquerque, NM); Cole, Jr., Edward I. (Albuquerque, NM); Tangyunyong, Paiboon (Albuquerque, NM); Soden, Jerry M. (Placitas, NM); Walraven, Jeremy A. (Albuquerque, NM); Pimentel, Alejandro A. (Albuquerque, NM)
Technology Assessment and Application Guide for the Utility Systems Technologies Voltage Sag Fighter
Voltage sag, a disturbance in a power system defined as a decrease in root mean square (RMS) voltage magnitude lasting from 0.5 to 30 cycles, has been identified as the most prevalent power disturbance experienced by industrial customers. The higher frequency of voltage sages makes them inherently more costly than interruptions since fault-induced, short-duration voltage variations can result in costly loss of production, damaged materials, repair and cleaning of equipment, and lost business opportunitie...
ETTM: Low Voltage System Protection and Coordination Computer-Based Training Version 1.0
ETTM Low Voltage System Protection and Coordination is a computer-based training module that allows users to access training when desired and review it at their own pace. It provides graphics and limited interactive features to enhance learning. Low voltage power systems are generally classified as AC power systems operating at the 120 600 Volt level. Because they often serve a large number of diverse loads in residences, businesses, and power plants, low voltage power systems present a unique set of cha...
Development of static and simulation programs for voltage stability studies of bulk power system
In the analysis and evaluation of voltage stability, it is necessary to accurately identify the stability margin at each load point under specific system configuration or power balance condition. Voltage stability margin can be basically identified by the multi-solution load flow calculation method. When predicted by this static analysis that voltage instability may occur, time domain simulation will be required which includes the models of various control equipments related with system voltage profile. To deal with this, the following two analytical computer codes shown below were developed. (1) Voltage stability static analysis computer code employing a new load flow calculation method. (2) Time domain long term simulation computer code for voltage stability. These computer codes can also calculate the voltage stability index at each load point which is based on the margin to the stability power limit at each load point. The practicality of these codes developed were verified by applying to the IEEE-118 test system.
Nagao, T.; Tanaka, K.; Takenaka, K. [Central Research Inst. of Electric Power Industry, Tokyo (Japan)
High voltage bus and auxiliary heater control system for an electric or hybrid vehicle
A control system for an electric or hybrid electric vehicle includes a vehicle system controller and a control circuit having an electric immersion heater. The heater is electrically connected to the vehicle's high voltage bus and is thermally coupled to a coolant loop containing a heater core for the vehicle's climate control system. The system controller responds to cabin heat requests from the climate control system by generating a pulse width modulated signal that is used by the control circuit to operate the heater at a duty cycle appropriate for the amount of cabin heating requested. The control system also uses the heater to dissipate excess energy produced by an auxiliary power unit and to provide electric braking when regenerative braking is not desirable and manual braking is not necessary. The control system further utilizes the heater to provide a safe discharge of a bank of energy storage capacitors following disconnection of the battery or one of the high voltage connectors used to transmit high voltage operating power to the various vehicle systems. The control circuit includes a high voltage clamping circuit that monitors the voltage on the bus and operates the heater to clamp down the bus voltage when it exceeds a pre-selected maximum voltage. The control system can also be used to phase in operation of the heater when the bus voltage exceeds a lower threshold voltage and can be used to phase out the auxiliary power unit charging and regenerative braking when the battery becomes fully charged.
Murty, Balarama Vempaty (West Bloomfield, MI)
A New Thermal-Conscious System-Level Methodology for Energy-Efficient Processor Voltage Selection
A New Thermal-Conscious System-Level Methodology for Energy-Efficient Processor Voltage Selection a thermal-conscious system-level methodology to make energy-efficient voltage selection (VS) for nanometer), thermal resistance, are integrated and considered in our system models, and their impacts on energy
Wang, Yu
Elevated Neutral to Earth and Contact Voltages in Distribution Systems
Perceptible voltage potentials at publicly and privately accessible human and animal contact locations pose concerns for utilities, regulators, and the public. Each year since 2004, EPRI research in this area has considered the most important concerns associated with these perceptible voltages by promoting consistent and repeatable assessment methodologies, sponsoring workshops, and creating a repository of case studies and general information. These and other project efforts are geared toward expediting...
Experiment and Simulation of Dynamic Voltage Regulation in Multiple Distributed Energy Resources Systems
Distributed energy (DE) resources are power sources located near load centers and equipped with power electronics converters to interface with the grid, therefore it is feasible for DE to provide reactive power (along with active power) locally for dynamic voltage regulation. In this paper, a synchronous condenser and a microturbine with an inverter interface are implemented in parallel in a distribution system to regulate the local voltage. Developed voltage control schemes for the inverter and the synchronous condenser are presented. Experimental results show that both the inverter and the synchronous condenser can regulate the local voltage instantaneously although the dynamic response of the inverter is much faster than the synchronous condenser. In a system with multiple DEs performing local voltage regulation, the interaction between the DEs is studied. The simulation results show the relationship between the voltages in the system and the reactive power required for the voltage regulation. Also, integrated voltage regulation (multiple DEs performing voltage regulation) can increase the voltage regulation capability of DEs and reduce the capital and operating costs.
Xu, Yan [ORNL; Li, Fangxing [ORNL; Kueck, John D [ORNL; Rizy, D Tom [ORNL
Modeling considerations in static and dynamic voltage stability studies of shipboard power systems
Better modeling is a key issue to system analysis and emulating real system performances accurately. This paper addresses modeling considerations and approaches to be taken for voltage stability analysis. Two approaches, static and dynamic analysis, ... Keywords: PSCAD, dynamic analysis, numerical integration method, static analysis, voltage stability
Minglan Lin; Anurag K. Srivastava; Noel N. Schulz
Energy Aware Dynamic Voltage and Frequency Selection for Real-Time Systems with Energy Harvesting
Energy Aware Dynamic Voltage and Frequency Selection for Real-Time Systems with Energy firstname.lastname@example.com Abstract In this paper, an energy aware dynamic voltage and frequency selection (EA-DVFS) algorithm energy and the harvested energy in a future duration. Specifically, if the system has sufficient energy
Qiu, Qinru
Investigating the electric power distribution system (EPDS) bus voltage in the presence of distributed generation (DG)
This paper investigates the Electric Power Distribution System (EPDS) bus voltage in the presence of Distributed Generation (DG). Distribution Company's (Discos) planner endeavor to develop new planning strategies for their network in order to serve ... Keywords: PSCAD, distributed generation, electric power distribution system, islanding, power quality, voltage stability
Hasham Khan; Mohammad Ahmad Choudhry; Tahir Mahmood; Aamir Hanif
2013 Call for Nominations
NLE Websites -- All DOE Office Websites (Extended Search)
2013 - Nominations are open for the 2013 NERSC Award for Innovative Use of High Performance Computing and the 2013 NERSC Award for High Impact Scientific Achievement. These are...
Analysis and Mitigation of Balanced Voltage Sag with the Help of Energy Storage System
Voltage sag is one of the major power quality problem which results in a failure or a mis-operation of end use equipments. Sensitive industrial loads and Utility distribution networks all suffer from various types of outages and service interruptions ... Keywords: Power quality, voltage sag, Custom power Devices, DVR, Energy Storage System, pulse width modulation
D. N. Katole; K. D. Joshi
Look-ahead voltage and load margin contingency selection functions for large-scale power systems
Given the current operating condition (obtained from the real-time data), the near-term load demand at each bus (obtained from short-term load forecast), and the generation dispatch (say, based on economic dispatch), the authors present in this paper a load margin measure (MW and/or MVAR) to assess the system`s ability to withstand the forecasted load and generation variations. The authors also present a method to predict near-term system voltage profiles. The proposed look-ahead measure and the proposed voltage prediction are then applied to contingency selections for the near-term power system in terms of load margins to collapse and of the bus voltage magnitudes. They evaluate the proposed load-ahead measure and the voltage profile prediction on several power systems including a 1169-bus power system with 53 contingencies with promising results.
Chiang, H.D.; Wang, C.S.; Flueck, A.J. [Cornell Univ., Ithaca, NY (United States). School of Electrical Engineering
Nomination Form DEPARTMENT / UNIT
Nomination Form DEPARTMENT / UNIT: CAMPUS ADDRESS: JOB TITLE: DEPARTMENT EMAIL ADDRESS: DEPARTMENT TELEPHONE: 2014 FRANKLIN STAFF EXCELLENCE AWARDS START DATE IN DEPARTMENT / UNIT: Nominee Information NAME / RESEARCHPROFESSIONAL Signature of Head / Director of Nominee's Unit: NOMINATION PACKET DEADLINE: MARCH 7, 2014 PLEASE
Arnold, Jonathan
Nomination Form DEPARTMENT / UNIT: CAMPUS ADDRESS: JOB TITLE: DEPARTMENT EMAIL ADDRESS: DEPARTMENT TELEPHONE: 2012 FRANKLIN STAFF EXCELLENCE AWARDS START DATE IN DEPARTMENT / UNIT: Nominee Information NAME / RESEARCHPROFESSIONAL Signature of Head / Director of Nominee's Unit: NOMINATION PACKET DEADLINE: FRIDAY MARCH 2, 2012
Nomination Form DEPARTMENT / UNIT: CAMPUS ADDRESS: JOB TITLE: DEPARTMENT EMAIL ADDRESS: DEPARTMENT TELEPHONE: 2011 FRANKLIN STAFF EXCELLENCE AWARDS START DATE IN DEPARTMENT / UNIT: Nominee Information NAME / RESEARCHPROFESSIONAL Signature of Head / Director of Nominee's Unit: NOMINATION PACKET DEADLINE: FRIDAY MARCH 4, 2011
Nomination Form DEPARTMENT / UNIT: CAMPUS ADDRESS: JOB TITLE: DEPARTMENT EMAIL ADDRESS: DEPARTMENT TELEPHONE: 2013 FRANKLIN STAFF EXCELLENCE AWARDS START DATE IN DEPARTMENT / UNIT: Nominee Information NAME / RESEARCHPROFESSIONAL Signature of Head / Director of Nominee's Unit: NOMINATION PACKET DEADLINE: MARCH 5, 2013 PLEASE
Application of multipoint DC voltage control in VSC-MTDC system
The voltage-source-converter- (VSC-) based multiterminal VSC-HVDC power transmission system (VSC-MTDC) is an ideal approach to connectwind farmwith power grid. Analyzing the characteristics of doubly fed induction generators aswell as the basic principle ...
Yang Xi, Ai Qian, Huang Jiantao, An Yiran
Curing system for high voltage cross linked cables
This invention makes extruded, vulcanized, high voltage cables insulated with thermosetting compounds at much higher rates of production and with superior insulation of reduced thickness and with reduced cavities or voids in the insulation. As the cable comes from an extruder, it passes into a curing chamber with a heat booster that quickly raises the insulation to a temperature at which it is cured much more quickly than with steam heating of the prior art. A high temperature liquid in contact with the insulation maintains the high temperature; and because of the greater curing heat, the cable can travel through the curing chamber at a faster rate and into a cooling tube where it contacts with a cooling liquid under high pressure. The insulation compound is treated to reduce the size of cavities; and the high pressure maintained by the curing and cooling mediums prevent expansion of cavities before the insulation is set.
Bahder, George (Edison, NJ); Katz, Carlos (Edison, NJ); Bopp, Louis A. (Fair Haven, NJ)
This thesis presents a thorough analysis of saddle-node bifurcations for power system dynamic models, including a third order representation of high voltage direct current (HVDC) transmission, classic ac generator dynamics with reactive flows, and voltage and frequency dependent load models. Extensions of the Point of Collapse and Continuation methods, initially used in ac system voltage stability studies, are applied to the determination of these bifurcation points. These methods are compared and used for calculating bus voltage profiles (�nose � curves) and collapse points on ac/dc systems of up to 2158 buses, considering a variety of operational limits and controls, namely, ac/dc regulating transformer tap limits, voltage and reactive power limits, and area interchange control. AC generator reactive power limits, HVDC firing angle limits and voltage dependent current order limits (VDCOL) are shown to affect the stability and loadability of these systems. A vector Lyapunov function approach is employed to define a system wide energy function that can be used for stability analysis. This thesis describes the derivation
Claudio A. Ca�izares
Nomination Form DEPARTMENT / UNIT: CAMPUS ADDRESS: CLASSIFICATION / TITLE: DEPARTMENT EMAIL ADDRESS: DEPARTMENT TELEPHONE: 2011 FRANKLIN STAFF SERVICE AWARDS START DATE IN DEPARTMENT / UNIT: ACTUAL NUMBER MEMBER DEADLINE: FRIDAY MARCH 4, 2011 ADDITIONAL COMMENTS: Signature of Head / Director of Nominee's Unit
Nomination Form DEPARTMENT / UNIT: CAMPUS ADDRESS: CLASSIFICATION / TITLE: DEPARTMENT EMAIL ADDRESS: DEPARTMENT TELEPHONE: 2013 FRANKLIN STAFF SERVICE AWARDS START DATE IN DEPARTMENT / UNIT: ACTUAL NUMBER MEMBER DEADLINE: MARCH 5, 2013 ADDITIONAL COMMENTS: Signature of Head / Director of Nominee's Unit
Nomination Form DEPARTMENT / UNIT: CAMPUS ADDRESS: CLASSIFICATION / TITLE: DEPARTMENT EMAIL ADDRESS: DEPARTMENT TELEPHONE: 2012 FRANKLIN STAFF SERVICE AWARDS START DATE IN DEPARTMENT / UNIT: ACTUAL NUMBER MEMBER DEADLINE: FRIDAY MARCH 2, 2012 ADDITIONAL COMMENTS: Signature of Head / Director of Nominee's Unit
Nomination Form DEPARTMENT / UNIT: CAMPUS ADDRESS: CLASSIFICATION / TITLE: DEPARTMENT EMAIL ADDRESS: DEPARTMENT TELEPHONE: 2014 FRANKLIN STAFF SERVICE AWARDS START DATE IN DEPARTMENT / UNIT: ACTUAL NUMBER MEMBER DEADLINE: MARCH 7, 2014 ADDITIONAL COMMENTS: Signature of Head / Director of Nominee's Unit
Lowering Power using the Voltage Identification Bit
Voltage identification is a form of adaptive voltage scaling (AVS). The voltage-identification technique described in this application note enables certain devices in the Virtex�-7 family to be operated at a lower voltage of 0.9V while delivering the same specified performance as that of a device operating at the nominal supply voltage of 1.0V. Voltage identification capable devices consume approximately 30 % lower worst case (maximum) static power and correspondingly dissipate less heat. Reduced power consumption is a desirable characteristic and one that Xilinx 7 series FPGAs fulfill in multiple ways. The primary purpose of the voltage-identification technique is to reduce the worst-case power consumption of-1C devices. However, the significance of the voltage-identification technique goes beyond an individual device dissipating less energy, it also can lower the overall system cost. Power supplies and thermal management requirements are normally specified based on the worst-case power demands of all the system�s components. Although the 7 series FPGAs-1C devices are the most cost-effective, the total cost of a product is the sum of all parts, and costs associated with the power supply and thermal management can be significant. The voltage-identification technique specifically reduces worst-case power consumption, which reduces the overall costs associated with specifying a larger power supply, requiring a heat sink, adding forced air cooling, or including similar devices. This application note shows the technical aspects of implementing the voltage-identification technique and introduces a reference design for the VC707 evaluation kit. It also explains how voltage identification fits into the complete power portfolio of Virtex-7 FPGAs and highlights the benefits of using the voltage-identification technique to reduce power consumption and system costs.
Ken Chapman; Jameel Hussein
Application Guidelines for Motor Control Circuits Protection and Control Circuits and Devices in the Voltage Sag Environment: System Compatibility Research
Common electrical disturbances in the power system-such as voltage sags and brief interruptions-can disrupt the performance of electronic equipment. This project, part of EPRI's ongoing Power Quality Measurements and Testing program, focused on developing a system compatibility test protocol and conducting power quality performance testing for motor voltage controllers operating in a voltage sag environment.
Engineering Technical Training Modules - Medium Voltage System Protection and Coordination Version 1.0
The purpose of this training module is to provide a basic understanding of protective relaying and coordination typically provided for medium voltage power systems. This module provides a discussion on current and potential transformers, the protective relays typically used as well as considerations for equipment protection and coordination or selective tripping. Medium voltage motor, transformer, and bus protection applications are covered. Lesson 4 focuses on emergency diesel generator protection in n...
Plant Support Engineering: Aging Management Program Guidance for Medium- Voltage Cable Systems for Nuclear Power Plants
Regulatory and management concern regarding the reliability of medium-voltage cable systems at nuclear plants has been increasing for 5�10 years. The staff of the U.S. Nuclear Regulatory Commission (NRC) are concerned that wetted (up to and including submergence) medium-voltage cable circuits may be degrading to the point at which multiple cable circuits may fail when called on to perform functions affecting safety. Utility managers are concerned that cables may fail, causing adverse safety consequences ...
System Voltage Potential-Induced Degradation Mechanisms in PV Modules and Methods for Test: Preprint
Over the past decade, degradation and power loss have been observed in PV modules resulting from the stress exerted by system voltage bias. This is due in part to qualification tests and standards that do not adequately evaluate for the durability of modules to the long-term effects of high voltage bias experienced in fielded arrays. High voltage can lead to module degradation by multiple mechanisms. The extent of the voltage bias degradation is linked to the leakage current or coulombs passed from the silicon active layer through the encapsulant and glass to the grounded module frame, which can be experimentally determined; however, competing processes make the effect non-linear and history-dependent. Appropriate testing methods and stress levels are described that demonstrate module durability to system voltage potential-induced degradation (PID) mechanisms. This information, along with outdoor testing that is in progress, is used to estimate the acceleration factors needed to evaluate the durability of modules to system voltage stress. Na-rich precipitates are observed on the cell surface after stressing the module to induce PID in damp heat with negative bias applied to the active layer.
Hacke, P.; Terwilliger, K.; Smith, R.; Glick, S.; Pankow, J.; Kempe, M.; Kurtz, S.; Bennett, I.; Kloos, M.
Trouble-Shooting Guide for Low-Voltage ASD/Motor Systems
ASD/low-voltage motor systems are used extensively by manufacturing and many other industries for a variety of reasons, including flexibility in manufacturing, energy conservation, and improved process control. There can be, however, reliability problems with ASD/motor systems. This report discusses ASD/motor system-related issues and provides guidance in identifying and solving the root causes of problems.
VOLTAGE COLLAPSE AND TRANSIENT ENERGY FUNCTION ANALYSES OF AC/DC SYSTEMS by Claudio A. Ca AND TRANSIENT ENERGY FUNCTION ANALYSES OF AC/DC SYSTEMS by Claudio A. Ca~nizares A dissertation submitted . . . . . . . . . . . . . 4 1.3.2 AC/DC Transient Energy Functions . . . . . . . . . . . . . . 6 2 System Modelling 8 2
Cañizares, Claudio A.
Secretarial Award Nomination Form
Secretary's Awards Program Nomination Form Secretary's Awards Program Nomination Form 1. Type of Award (Check Applicable Box) Secretary's Honor Awards Secretary's Departure Awards Secretary's James R. Schlesinger Award Exceptional Service Award Appreciation Award Excellence Award Distinguished Service Award Achievement Award Meritorious Service Award 2. Nominee (Full) Name Check if Group list is attached (As it is to appear on the certificate) For Departure and Appreciation Awards Only 3. Certificate Date 4. Award Presentation Date 5. Current Position Title 6. Award Justification: Continue on blank sheet of paper and attach if you need more space. 7. Award Citation: A citation of no more than 20 lines must be attached to nomination form. 8 . Requesting Office : 9a. Local Approvals: One or more signatures is typical but not required
Technical interactions between distributed photovoltaic systems and low-voltage grids
In the European Research Program ICOP DEMO 4080-98 there was installed a photovoltaic system of 10kWp made of 66 photovoltaic modules model OPTISOL SFM 72 Bx made by Pilkington Solar International and 24 ST 40 modules made by SIEMENS at the University ... Keywords: distributed generation, harmonic analysis, low-voltage grids, photovoltaic system, quality parameters, renewable energy
Traian Daniel Ivanovici; Marcel Ionel; Mihail-Florin Stan; Valentin Dogaru-Ulieru; Ioan Corneliu Salisteanu
Stability boundary analysis of the dynamic voltage restorer in weak systems with dynamic loads
In this contribution, a stability analysis for a dynamic voltage restorer (DVR) connected to a weak ac system containing a dynamic load is presented using continuation techniques and bifurcation theory. The system dynamics are explored through the continuation ... Keywords: DVR, Floquet multiplier, active filter, continuation techniques, iterative map, point common coupling, power converter, stability regions, switching process
Juan Segundo-Ram�rez; Aurelio Medina; Arindam Ghosh; Gerard Ledwich
Effects of voltage control in utility interactive dispersed storage and generation systems
When a small generator is connected to the distribution system, the voltage at the point of interconnection is determined largely by the system and not the generator. This report examines the effect on the generator, on the load voltage and on the distribution system of a number of different voltage control strategies in the generator. Synchronous generators with three kinds of exciter control are considered, as well as induction generators and dc/ac inverters, with and without capacitor compensation. The effect of varying input power during operation (which may be experienced by generators based on renewable resources) is explored, as well as the effect of connecting and disconnecting the generator at ten percent of its rated power.
Kirkham, H.; Das, R.
The System Impact of Air-Conditioner Under-voltage Protection Schemes
This paper presents simulation results of evaluating an under-voltage protection scheme designed to take stalled air-conditioner (a/c) units offline such that the slow voltage recovery phenomena can be solved on areas heavily loaded with a/c motors during summer peak periods. A three feeder test-bed has been first used to quantify the effectiveness of the protection scheme and the sensitivity of the under-voltage relay settings. Then two real system events of the Western US power grid have been studied to evaluate the area impact of the protection scheme proposed by Southern California Edison. The study demonstrates that by taking all or most of the stalled a/c unit offline, the feeder voltage will recover in a few seconds, much quicker than the tens of seconds that the standard thermal relays imbedded in the motors need to trip the units. The drawback of the control scheme is that after the voltage recover, it settled at a higher voltage than before the faults because a large chuck of load has been shed.
Lu, Ning; Yang, Bo; Huang, Zhenyu; Bravo, Richard
Combined transmission distribution load flow model employing system reduction and voltage variable load representation
In the few decades since its introduction the digital computer has found widespread application within the electric power industry. One of the more fruitful areas for its utilization has been in the determination of the steady-state voltage conditions throughout the system. A power system naturally breaks down into two very distinct parts: transmission and distribution, and traditionally, the voltage problem has been separated the same way. In the transmission system it is referred to as a load flow problem, and in the distribution part it is called a voltage profile. In addition, the loads are often treated differently. Transmission loads are usually considered to be constant power, and the equations that result are therefore nonlinear. In the distribution portion the loads, though specified in terms of power, are sometimes handled as constant impedances, with linear equations. This work produced a new model wherein a mesh transmission system is combined with a radial distribution system and they are solved simultaneously. A system reduction technique is used to eliminate part of the transmission system from consideration, and thereby keep the problem at a manageable size. The solution algorithm incorporates a voltage variable load model which approximates the behavior of real loads more nearly than the common representations.
Enouen, P.W.
Utility-Side Voltage and PQ Control with Inverter-based Photovoltaic Systems
Distributed energy resources (DER) are small generators located close to the load centers. The DERs that are integrated to the grid with the power electronic converter interfaces are capable of providing nonactive power in addition to active power. Hence, they are capable of regulating the voltages of the weak buses in the distribution systems. This paper discusses the voltage control capability of photovoltaic (PV) systems as compared to the traditional capacitor banks. The simulation results prove the effectiveness of dynamic voltage control capability of inverter-based PV. With the proper control algorithm, the active and nonactive power from the DERs like battery banks or solar photovoltaic can be controlled independently. This paper also presents the scenario of controlling the active and nonactive power from the PV array to track and supply the local load.
Adhikari, Sarina [ORNL; Xu, Yan [ORNL; Li, Fangxing [ORNL; Li, Huijuan [ORNL; Kueck, John D [ORNL; Snyder, Isabelle B [ORNL; Barker, Thomas J. [Southern California Edison RTTC; Hite, Ronald [Southern California Edison RTTC
Modeling and Verification of Distributed Generation and Voltage Regulation Equipment for Unbalanced Distribution Power Systems; Annual Subcontract Report, June 2007
This report summarizes the development of models for distributed generation and distribution circuit voltage regulation equipment for unbalanced power systems and their verification through actual field measurements.
Davis, M. W.; Broadwater, R.; Hambrick, J.
BATTERY AWARE TASK SCHEDULING FOR A SYSTEM-ON-A-CHIP USING VOLTAGE/CLOCK SCALING Princey Chowdhury Engineering Tempe AZ 85287 ABSTRACT Battery lifetime is a critical parameter in the operation of mobile computing devices. The lifetime of such devices is directly dependent on the battery discharge profile
Chakrabarti, Chaitali
An enhanced dynamic voltage scaling scheme for energy-efficient embedded real-time control systems
Real-Time Dynamic Voltage Scaling (RT-DVS) has been one of the most important techniques for energy savings in battery-powered embedded systems. However, pure RT-DVS approaches rarely take into account the actual performance requirements of the target ...
Feng Xia; Youxian Sun
A Two-Stage Distributed Architecture for Voltage Control in Power Distribution Systems
-positive power injections. With respect to this, the University of Illinois solar decathlon house--the Gable Home by the US DOE Smart Grid initiative, and its European counterpart Electricity Networks of the Future, power1 A Two-Stage Distributed Architecture for Voltage Control in Power Distribution Systems Brett A
Hadjicostis, Christoforos
Using phasors to analyze power system negative phase sequence voltages caused by unbalanced loads
An analytical method is demonstrated which allows the level of negative phase sequence (NPS) voltage at a busbar to be expressed as a sum of phasors representing independent sources. The method is extended to enable the balancing capability of Static Var Compensators (SVCs) with individual phase voltage control to be assessed. The capability of such SVCs and the allowable levels of NPS voltage on the system, including any short term limits, can be combined in a capability chart showing the unbalanced loads which can be supplied from a substation. The approach facilitates the treatment of fixed unbalances due to filters or intentional offsets designed to maximize the SVC balancing range for specific loads. Field test results are presented which validate the analytical methods used.
Ledwich, G. (Univ. of Queensland, St. Lucia (Australia)); George, T.A. (Queensland Electricity Commission, Brisbane (Australia))
Feasibility of high-voltage systems for a very long drift in liquid argon TPCs
Designs of high-voltage (HV) systems for creating a drift electric field in liquid argon TPCs are reviewed. In ongoing experiments systems capable of approx. 100 kV are realised for a drift field of 0.5-1 kV/cm over a length of up to 1.5 m. Two of them having different approaches are presented: (1) the ICARUS-T600 detector having a system consisting of an external power supply, HV feedthroughs and resistive voltage degraders and (2) the ArDM-1t detector having a cryogenic Greinacher HV multiplier inside the liquid argon volume. For a giant scale liquid argon TPC, a system providing 2 MV may be required to attain a drift length of approx. 20 m. Feasibility of such a system is evaluated by extrapolating the existing designs.
Horikawa, S; Kaufmann, L; Laffranchi, M; Marchionni, A; Messina, M; Natterer, G; Rubbia, A
Nomination Letter for Gale Warshawsky
February 12, 1996. I nominate Gale Warshawsky of Lawrence Livermore National Laboratories (LLNL) for the FISSEA Educator of the Year. ...
PAPER ACCEPTED TO IEEE TRANSACTIONS ON POWER SYSTEMS, Nov. 2008 1 Reactive Power and Voltage Control in Distribution
PAPER ACCEPTED TO IEEE TRANSACTIONS ON POWER SYSTEMS, Nov. 2008 1 Reactive Power and Voltage) problem associated with reactive power and voltage control in distribution systems to minimize daily on the number of switching operations of transformer load tap changers (LTCs) and capacitors, which are modeled
Application of genetic algorithm to improve voltage regulation of self-excited induction generator in a wind energy conversion system
Self-excited induction generators have been found to be most suitable for wind energy conversion in remote locations. In this paper, an attempt has been made to improve the voltage regulation of self-excited induction generator (SEIG) using series compensation. ... Keywords: genetic algorithms, intelligent systems, modelling, renewable energy, self-excited induction generators, simulation, voltage regulation, wind energy conversion systems, wind power
Dheeraj Joshi; K. S. Sandhu; M. K. Soni
Transient and harmonic voltages associated with automated capacitor switching on distribution systems
One of the functions proposed for distribution automation systems is automated capacitor switching to control power factor and voltage profile on feeder circuits. This is one of the functions being implemented as part of the Athens Automation and Control Experiment on the Athens Utilities Board (AUB) in Athens, Tennessee. A concern with automated capacitor switching is the increase in harmonic and transient voltages due to different capacitor configurations on the distribution system. A study was performed to evaluate the impact of the automated capacitor switching on the AUB distribution system. The study has identified problem areas, methods for determining the problem areas, and possible solutions. The substation capacitor banks were found to be the dominant factor in both the transient and harmonic responses of the distribution system. The harmonic response of the system is dominated by the parallel inductance/capacitance of the circuit comprised of the substation capacitor and equivalent source reactance at the substation. The transient analyses indicated that when the substation capacitor is energized, magnified transient voltages can occur at switched-in feeder capacitors. An evaluation of the effect of automated capacitor switching is necessary to properly design the automated capacitor switching schemes and the required arrester protection for any harmonic and/or transient overvoltage contingency.
Rizy, D.T.; Gunther, E.W.; Mc Granaghan, M.F.
One of the functions proposed for distribution system automation is automated capacitor switching to control power factor and voltage profile on feeder circuits. This is one of the functions being implemented as part of the Athens Automation and Control Experiment on the Athens Utilities Board (AUB) in Athens, Tennessee. A concern with automated capacitor switching is the increase in harmonic and transient voltages due to different capacitor configurations on the distribution system. A study was performed to evaluate the impact of the automated capacitor switching on the AUB distribution system. The study has identified problem areas, methods for determining the problem areas and possible solutions. The substation capacitor banks were found to be the dominant factor in both the transient and harmonic responses of the distribution system. The harmonic response of the system is dominated by the parallel inductance/capacitance of the circuit comprised of the substation capacitor and equivent source reactance at the substation. The transient analyses found that when the substation capacitor is energized, magnified transient voltages can occur at switched in feeder capacitors. An evaluation of the effect of automated capacitor switching is necessary to properly design tha automated capacitor switching schemes and the required arrester protection for any harmonic and/or transient overvoltage contingency.
Rizy, D.T.; Gunther, E.W.; McGranaghan, M.F.
Methods, systems and apparatus for approximation of peak summed fundamental and third harmonic voltages in a multi-phase machine
Methods, system and apparatus are provided for quickly approximating a peak summed magnitude (A) of a phase voltage (Vph) waveform in a multi-phase system that implements third harmonic injection.
Ransom, Ray M. (Big Bear City, CA); Gallegos-Lopez, Gabriel (Torrance, CA); Kinoshita, Michael H. (Redondo Beach, CA)
Logic and Memory Design Based on Unequal Error Protection for Voltage-scalable, Robust and Adaptive DSP Systems
In this paper, we propose a system level design approach considering voltage over-scaling (VOS) that achieves error resiliency using unequal error protection of different computation elements, while incurring minor quality degradation. Depending on user ... Keywords: Low power, Memory design, Supply voltage scaling, Variation aware design
Georgios Karakonstantis; Debabrata Mohapatra; Kaushik Roy
Low-voltage, low-power circuits for data communication systems
There are growing industrial demands for low-voltage supply and low-power consumption circuits and systems. This is especially true for very high integration level and very large scale integrated (VLSI) mixed-signal chips and system-on-a-chip. It is mainly due to the limited power dissipation within a small area and the costs related to the packaging and thermal management. In this research work, two low-voltage, low-power integrated circuits used for data communication systems are introduced. The first one is a high performance continuous-time linear phase filter with automatic frequency tuning. The filter can be used in hard disk driver systems and wired communication systems such as 1000Base-T transceivers. A pseudo-differential operational transconductance amplifier (OTA) based on transistors operating in triode region is used to achieve a large linear signal swing with low-voltage supplies. A common-mode (CM) control circuit that combines common-mode feedback (CMFB), common-mode feedforward (CMFF), and adaptive-bias has been proposed. With a 2.3V single supply, the filter?s total harmonic distortion is less than ?44dB for a 2VPP differential input, which is due to the well controlled CM behavior. The ratio of the root mean square value of the ac signal to the power supply voltage is around 31%, which is much better than previous realizations. The second integrated circuit includes two LVDS drivers used for high-speed point-to-point links. By removing the stacked switches used in the conventional structures, both LVDS drivers can operate with ultra low-voltage supplies. Although the Double Current Sources (DCS) LVDS driver draws twice minimum static current as required by the signal swing, it is quite simple and achieves very high speed operation. The Switchable Current Sources (SCS) LVDS driver, by dynamically switching the current sources, draws minimum static current and reduces the power consumption by 60% compared to the previously reported LVDS drivers. Both LVDS drivers are compliant to the standards and operate at data rates up to gigabits-per-second.
Chen, Mingdeng
Technical evaluation of the adequacy of station electric distribution system voltages for the Yankee Rowe Nuclear Power Station
This report documents the technical evaluation of the adequacy of the station electric distribution system voltages for the Yankee Rowe Nuclear Power Station. The evaluation is to determine if the onsite distribution system, in conjunction with the offsite power sources, has sufficient capacity to automatically start and operate all Class 1E loads within the equipment voltage ratings under certain conditions established by the Nuclear Regulatory Commission. The analysis shows that the station electric distribution system has the capacity and capability to supply voltage to the Class 1E equipment with their design ratings for the worst case loading condition.
Selan, J.C.
A Multiphase, Modular, Bidirectional, Triple-Voltage DC-DC Converter Power Systems
Electrical power systems in future hybrid and fuel cell vehicles may employ three voltage [14 V, 42 V, and high voltage (HV)] nets. These will be necessary to accommodate existing 14-V loads as well as efficiently handle new heavy loads at the 42-V net and a traction drive on the HV bus. A low-cost DC-DC converter was proposed for connecting the three voltage nets. It minimizes the number of switches and their associated gate driver components by using two half-bridges and a high-frequency transformer. Another salient feature is that the half bridge on the 42-V bus is also utilized to provide the 14-V bus by operating at duty ratios around an atypical value of 1/3. Moreover, it makes use of the parasitic capacitance of the switches and the transformer leakage inductance for soft switching. The use of half bridges makes the topology well suited for interleaved multiphase modular configurations as a means to increase the power level because the capacitor legs can be shared. This paper presents simulation and experimental results on an interleaved two-phase arrangement rated at 4.5 kW. Also discussed are the benefits of operating with an atypical duty ratio on the transformer and a preferred multiphase configuration to minimize capacitor ripple currents.
Su, Gui-Jia [ORNL; Tang, Lixin [ORNL
Technical evaluation of the adequacy of station electric-distribution-system voltages for the Pilgrim Nuclear Power Station, Unit 1
This report documents the technical evaluation of the adequacy of the station electric distribution system voltages for the Pilgrim Nuclear Power Station, Unit 1. The evaluation is to determine if the onsite distribution system in conjunction with the offsite power sources has sufficient capacity to automatically start and operate all Class 1E loads within the equipment voltage ratings under certain conditions established by the Nuclear Regulatory Commission. The analyses demonstrated that for the worst case conditions established, the Class 1E equipment will automatically start and continue to operate within the equiment design voltage rating.
Reactive and voltage monitoring: The challenge for the system operators in the 1980's
In order to gain perspective on the monitoring program for PJM, background relative to the physical characteristics and operating philosophy of the pool is offered. PJM is comprised of 11 electric utilities serving approximately 48,700 square miles, encompassing about 75% of Penna, 97% of N.J., all of Del and the District of Columbia, 60% of Md, and 1% of Va. The generating capability is comprised of 532 units at 116 generating stations, and totals approximately 45,000 MW. The PJM system peak load for 1980 was 34,420 MW. PJM has 27 tie lines with its neighboring systems. Although comprised of 11 utilities, the PJM system is operated as if it were a single company. Reasons for the PJM real-time monitoring system are presented and relevant details are discussed. Topics considered include operating criteria. Reactive and Voltage Monitoring, Current Operating Restrictions off-line analysis, and future requirements are discussed.
Willson, J.D.
EPRI High-Voltage Direct Current (HVDC) Reference Book: Chapter 24 - Operation and Maintenance of HVDC Systems
This report contains descriptions of the operation and maintenance (O&M) activities of traditional high-voltage direct current (HVDC) line commutated (thyristor-based) and voltage-sourced converter (VSC) transmission systems. Both long-distance transmission schemesincluding the transmission linesand back-to-back schemes are included. The various tasks involved in the O&M of HVDC systems are described at some length, and a range of estimates is given for the staff requirements to carry out these activitie...
Real Power and Reactive Power Control of a Three-Phase Single-Stage-PV System and PV voltage Stability
Grid-connected photovoltaic (PV) systems with power electronic interfaces can provide both real and reactive power to meet power system needs with appropriate control algorithms. This paper presents the control algorithm design for a three-phase single-stage grid-connected PV inverter to achieve either maximum power point tracking (MPPT) or a certain amount of real power injection, as well as the voltage/var control. The switching between MPPT control mode and a certain amount of real power control mode is automatic and seamless. Without the DC-to-DC booster stage, PV DC voltage stability is an important issue in the control design especially when the PV inverter is operating at maximum power point (MPP) with voltage/var control. The PV DC voltage collapse phenomenon and its reason are discussed. The method based on dynamic correction of the PV inverter output is proposed to ensure PV DC voltage stability. Simulation results of the single-stage PV system during system disturbances and fast solar irradiation changes confirm that the proposed control algorithm for single-stage PV inverters can provide appropriate real and reactive power services and ensure PV DC voltage stability during dynamic system operation and atmospheric conditions.
Li, Huijuan [ORNL; Xu, Yan [ORNL; Adhikari, Sarina [ORNL; Rizy, D Tom [ORNL; Li, Fangxing [ORNL; Irminger, Philip [ORNL
Adaptive fuzzy regulation of the DC-bus capacitor voltage in a wind energy conversion system (WECS)
This paper proposes a new voltage regulator of the DC-bus capacitor of a variable speed wind power generation system based on adaptive fuzzy system. The change in the fuzzy rule base is done using a variable-structure direct adaptive control algorithm ... Keywords: Adaptive control, Fuzzy systems, Wind energy conversion systems
A. L. Elshafei; M. A. Azzouz
Plant Engineering, Aging Management Program Guidance for Medium-Voltage Cable Systems for Nuclear Power Plants, Revision 1
This report was prepared in response to regulatory and management concern regarding the reliability of medium-voltage cable systems at nuclear plants. The staff of the U.S. Nuclear Regulatory Commission (NRC) have been concerned that wetted (up to and including submergence) medium-voltage cable circuits may be degrading to the point at which multiple cable circuits may fail when called on to perform functions affecting safety. A utility manager�s concern is that cables may fail, causing ...
Analysis of system wide distortion in an integrated power system utilizing a high voltage DC bus and silicon carbide power devices
This research investigates the distortion on the electrical distribution system for a high voltage DC Integrated Power System (IPS). The analysis was concentrated on the power supplied to a propulsion motor driven by an ...
Fallier, William F. (William Frederick)
Assessment of research directions for high-voltage direct-current power systems. Final report
High voltage direct current (HVDC) power transmission continues to be an emerging technology nearly thirty years after its introduction into modern power systems. To date its use has been restricted to either specialized applications having identifiable economic advantages (e.g., breakeven distance) or, rarely, applications where decoupling is needed. Only recently have the operational advantages (e.g., power modulation) of HVDC been realized on operating systems. A research project whose objective was to identify hardware developments and, where appropriate, system applications which can exemplify cost and operational advantages of integrated ac/dc power systems is discussed. The three principal tasks undertaken were: assessment of equipment developments; quantification of operational advantages; and interaction with system planners. Interest in HVDC power transmission has increased markedly over the past several years, and many new systems are now being investigated. The dissemination of information about HVDC, including specifically the symposium undertaken for Task 3, is a critical factor in fostering an understanding of this important adjunct to ac power transmission.
Long, W F
Routing in Cyber Physical Systems with Application for Voltage Control in Microgrids: A Hybrid System Approach
A key challenge of cyber physical system is how to design the communication system. In this paper, the framework of hybrid system which consists of both continuous and discrete system states is adopted for the communication system design, particularly ... Keywords: cyber physical system, hybrid systems, routing
Husheng Li; Robert C. Qiu; Zhiqiang Wu
Impact of High-Penetration PV on Distribution System Performance: Assessment of Regulation Control Options for Voltage Mitigation
Photovoltaics are beginning to challenge distribution system power engineers nationwide. The impact photovoltaics (PV) has on the power system is directly tied to system characteristics which include but are not limited to voltage class, load, regulation, and short circuit capacity. In addition to the system characteristics, the solar characteristics also play a key role. These include details on the PV systems themselves in addition to the solar irradiance data. The correlation of PV output and ...
Power-aware scheduling and dynamic voltage setting for tasks running on a hard real-time system
Abstract- This paper addresses the problem of minimizing energy consumption of a computer system performing periodic hard real-time tasks with precedence constraints. In the proposed approach, dynamic power management and voltage scaling techniques are combined to reduce the energy consumption of the CPU and devices. The optimization problem is first formulated as an integer programming problem. Next, a three-phase solution framework, which integrates power management scheduling and task voltage assignment, is proposed. Experimental results show that the proposed approach outperforms existing methods by an average of 18 % in terms of the system-wide energy savings. I.
Peng Rong
the accel voltage reg� ulation requirement could be relaxedVOLTAGE SWITCHES TUBES SCR ASSEMBLIES CROSSED-FIELD INTERRUPTERS MAGNETIC CORE ARC SNUEBER3 COMPUTERS FOR CONTROL AND DIAGNOSTICS OPERATIONAL REQUIREMENTSvoltage- regulated (flat-topped) to 1%. If good regulation Is not a prime requirement,
Baker, W.R.
Voltage protection scheme for MG sets used to drive inductive energy storage systems
A recent tokamak proposal at ORNL called for MG (motor-generator) sets to drive the ohmic heating (OH) coil, which was to be subjected to 20 kV immediately after coil charge-up to initiate the experiment. Since most rotating machinery is inherently low voltage, including the machines available at ORNL, a mechanism was necessary to isolate the generators from the high voltage portions of the circuit before the appearance of this voltage. It is not the expected 20 kV at the coil that causes difficulty, because the main interrupting switch handles this. The voltage induced in the armature due to di/dt and the possibility of faults are the greatest causes for concern and are responsible for the complexity of the voltage protection scheme, which must accommodate any possible combination of fault time and location. Such a protection scheme is presented in this paper.
Campen, G.L.; Easter, R.B.
Capabilities of the High Voltage Stress Test System at the Outdoor Test Facility
We illustrate the capabilities of the High Voltage Stress Test (HVST) which operates continuously in the array field east of the Outdoor Test Facility at the National Renewable Energy Laboratory. Because we know that photovoltaic (PV) modules generating electrical power in both residential and utility-scale array installations will develop high-voltage biases approaching 600 VDC and 1,000 VDC, respectively, we expect such high voltages will result in current leakage between cells and ground, typically through the frames or mounts. We know that inevitably such leakage currents are capable of producing electrochemical corrosion that adversely impacts long-term module performance. With the HVST, we stress or operate PV modules under high-voltage bias, to characterize their leakage currents under all prevailing ambient conditions and assess performance changes emanating from high-voltage stress. We perform this test both on single modules and an active array.
del Cueto, J. A.; Trudell, D.; Sekulic, W.
Characterization of Multicrystalline Silicon Modules with System Bias Voltage Applied in Damp Heat
As it is considered economically favorable to serially connect modules to build arrays with high system voltage, it is necessary to explore potential long-term degradation mechanisms the modules may incur under such electrical potential. We performed accelerated lifetime testing of multicrystalline silicon PV modules in 85 degrees C/ 85% relative humidity and 45 degrees C/ 30% relative humidity while placing the active layer in either positive or negative 600 V bias with respect to the grounded module frame. Negative bias applied to the active layer in some cases leads to more rapid and catastrophic module power degradation. This is associated with significant shunting of individual cells as indicated by electroluminescence, thermal imaging, and I-V curves. Mass spectroscopy results support ion migration as one of the causes. Electrolytic corrosion is seen occurring with the silicon nitride antireflective coating and silver gridlines, and there is ionic transport of metallization at the encapsulant interface observed with damp heat and applied bias. Leakage current and module degradation is found to be highly dependent upon the module construction, with factors such as encapsulant and front glass resistivity affecting performance. Measured leakage currents range from about the same seen in published reports of modules deployed in Florida (USA) and is accelerated to up to 100 times higher in the environmental chamber testing.
Hacke, P.; Kempe, M.; Terwilliger, K.; Glick, S.; Call, N.; Johnston, S.; Kurtz, S.
A new measurement technique for tracking voltage phasors, local system frequency, and rate of change of frequency
With the advent of Substation Computer Systems dedicated to protection, control and data logging functions in a Substation, it becomes possible to develop new applications which can utilize the processing power available within the substation. The microcomputer based Symmetrical Component Distance Relay (SCDR) described in the references cited at the end of this paper possesses certain characteristics which facilitate real-time monitoring of positive sequence voltage phasor at the local power system bus. With a regression analysis the frequency and rate-of-change of frequency at the bus can also be determined from the positive sequence voltage phase angle. This paper describes the theoretical basis of these computations and describes results of experiments performed in the AEP power system simulation laboratory. Plans for future field tests on the AEP system are also outlined.
Phadke, A.G.; Adamiak, M.G.; Thorp, J.S.
National Defense University (NDU) Nomination Package Checklist
- November 2012 - November 2012 National Defense University (NDU) Nomination Package Checklist SEND 2 COPIES OF THE NOMINATION PACKAGE TO THE NDU UNIVERSITY REGISTRAR'S OFFICE Each student nomination package must include the following items: NDU Student Nomination Form One official transcript (highest degree earned) One-page student biography or résumé (include education and career history) Two Letters of Recommendation World-Wide Travel Statement Statement of Purpose (No more than two pages) Signed National Defense University Privacy Act Statement Signed Education Release Form (if nominating agency requires copies of final student evaluation and/or transcript) SAC students must also include: Senior Acquisition Course Nomination Form
Shootthrough fault protection system for bipolar transistors in a voltage source transistor inverter
Faulted bipolar transistors in a voltage source transistor inverter are protected against shootthrough fault current, from the filter capacitor of the d-c voltage source which drives the inverter over the d-c bus, by interposing a small choke in series with the filter capacitor to limit the rate of rise of that fault current while at the same time causing the d-c bus voltage to instantly drop to essentially zero volts at the beginning of a shootthrough fault. In this way, the load lines of the faulted transistors are effectively shaped so that they do not enter the second breakdown area, thereby preventing second breakdown destruction of the transistors.
Wirth, W.F.
High power impulse magnetron sputtering: Current-voltage-time ...
pauses between pulses !typically 20 ms". The nominal volt-age of the pulser was adjustable up to 1000 V. The arc threshold was set to 120 A. If the current exceeded this
A monitor and control system for high voltage, gating, and triggering of a scintillating fiber active target
A monitor and control system has been designed, constructed and tested at Notre Dame for the purpose of controlling all aspects of a Scintillating Fiber Acxtive Target system used in High Energy Physics Experimentation. The SFT Active Target system requires control of high voltages, gating, trigger counters, and monitoring. In addition, it resides in a radioactive area with very limited access. The control system uses a Leading Edge microcomputer, two specialized Z80-based processors, associated DACs, ADCs, discrete semiconductors, linear ICs and TTL and MECL logic. All of the hardware and software is custom-built; its design and performance is discussed.
Baumbaugh, B.; Bishop, J.; Gardner, R.W.; Mountain, R.J.; Ruchti, R.; Baumbaugh, A.; Knickerbocker, K.
A monitor and control system has been designed, constructed and tested at Notre Dame for the purpose of controlling all aspects of a Scintillating Fiber Active Target system used in High Energy Physics Experimentation. The SFT Active Target system requires control of high voltages, gating, trigger counters, and monitoring. In addition, it resides in a radioactive area with very limited access. The control system uses a Leading Edge microcomputer, two specialized Z80-based processors, associated DACs, ADCs, discrete semiconductors, linear ICs, and TTL and MECL logic. All of the hardware and software is custom-built; its design and performance is discussed. 5 refs., 4 figs.
Research on Low-Voltage Ride-Through Technology of Doubly-Fed VSCF Wind Power Generation System
Currently, some of the variable speed wind turbine on market have some low-voltage through capacity?LVRT?, but do not have dynamic reactive power support capacity under fault. DFIG can�t provide dynamic voltage support, in addition, ... Keywords: wind power, voltage dip, low voltage ride-through (LVRT), transient voltage control, rotor-side converter
Bao Wei; Yin Zhongdong
savings tn the power conditioning transformers would result.power supply would be extremely simple, involving as major components only primary contactors, voltage-variable transformer,transformer reactance. For the LBL 160-kV, 75-A NBSTF Accel power
Grounding studies in a medium voltage DC shipboard power system with uncertain parameters
In this paper, the response surface modeling approach is applied to study the effectiveness of different grounding schemes implemented for the mitigation of single-line-to-ground faults in a simulation of a notional Medium Voltage DC shipboard power ... Keywords: Gaussian process model, Sobol indices, multivariate adaptive regression splines (MARS)
Dorca Lee; Diomar Infante; James Langston; Svetlana V. Poroseva; Michael Steurer; Thomas Baldwin
Energy aware dynamic voltage and frequency selection for real-time systems with energy harvesting
In this paper, an energy aware dynamic voltage and frequency selection (EA-DVFS) algorithm is proposed. The EA-DVFS algorithm adjusts the processor's behavior depending on the summation of the stored energy and the harvested energy in a future duration. ...
Shaobo Liu; Qinru Qiu; Qing Wu
Full abstraction for nominal Scott domains
We develop a domain theory within nominal sets and present programming language constructs and results that can be gained from this approach. The development is based on the concept of orbit-finite subset, that is, a subset of a nominal sets that is ... Keywords: denotational semantics, domain theory, full abstraction, nominal sets, symmetry
Steffen L�sch; Andrew M. Pitts
A new converter fault discrimination method for a 12-pulse high-voltage direct current system based on wavelet transform and Hidden Markov Models
The progressive development in high-voltage direct current (HVDC) transmission enhances the need to implement an efficient protection scheme to distinguish the minimum faulty part of the system and to relieve the stressed equipment. This paper proposes ... Keywords: Discrete Hidden Markov Models, converter faults, fault discrimination, high-voltage direct current, wavelet transform
Mohamad Tahan; Hassan Monsef; Shahrokh Farhangi
Nominations Open for 2013 NERSC HPC Achievement Awards
Nominations Open for 2013 NERSC HPC Achievement Awards Nominations Open for 2013 NERSC HPC Achievement Awards January 1, 2013 by Richard Gerber (0 Comments) Nominations are open...
Surge voltage suppression in residential power circuits
... Tran- sients in Low Voltage Supply Systems,'' The ... a high-voltage transformer for an oil furnace ... of service entrance SPD of 1960-1970 vintage were ...
Probabilistic voltage assessment and VAR compensation
The system voltage profile subject to system elements' forced outage is accessed. Two system voltage reliability indexes are evaluated: the loss of voltage probability, and the expected voltage violation. A similar set of two voltage reliability indexes are also calculated for every load bus in the system. A simple VAR compensation approach is introduced. It enhances the voltage profile assuming a maximum of three overlapping element outages can occur. For purposes of demonstration, the system and load bus voltage reliability indexes are calculated for the AEP 30-bus system. Results of applying the proposed VAR compensation scheme to the 30-bus system are also presented and discussed.
Sharaf, T.A.M.; Berg, G.J.
Demonstration of Commissioning Tests for Extra-High Voltage Cross-Linked Polyethylene Cable Systems at Los Angeles Department of Wat er and Power
Today, utilities are installing an increasing number of cross-linked polyethylene (XLPE) transmission cables with system voltages ranging from 115 kV up to 345 kV. This report summarizes field partial discharge measurements and high-voltage ac commissioning tests performed on a Los Angeles Department of Water and Power (LADWP) 230-kV XLPE transmission cable system. The commissioning tests were performed with a field transportable, variable frequency, series resonant test set at 1.4 times rated voltage.
Motor voltage asymmetry influence to the efficient energy usage
Analysis of the effect of unbalanced voltages on the three-phase induction motor is presented in the paper. Since the unbalanced voltage of 2%, 3.5% and 5% increase in losses could reach, in the same order, the amount of 8%, 25% and 50% of nominal power ... Keywords: asymetry, energy efficiency, induction motor, power losses, standard
Miloje Kostic; Aleksandar Nikolic
2014 Call for HPC Achievement Award Nominations
Award Nominations are open for the 2014 NERSC Award for Innovative Use of High Performance Computing and the 2014 NERSC Award for High Impact Scientific Achievement. NERSC...
Remediation strategies of shaft and common mode voltages in adjustable speed drive systems.
??AC motors are largely used in a wide range of modern systems, from household appliances to automated industry applications such as: ventilations systems, fans, pumps,� (more)
Adabi Firouzjaee, Jafar
Integrated Technology for Distribution Systems Applications: Survey and Testing of Voltage Detecting/Indicating Devices for AC Power Lines
This report summarizes product reviews and testing commercially available voltage-sensing devices used to detect energized electric distribution lines, with particular focus on minimum detection and indication performance. To adequately detect line energization across the entire spectrum of possible voltage levels on a power line (from 40 Vac to full line voltage), multiple devices are currently necessary. The ideal improvement to address current gaps in voltage sensing would be the development of a ...
A Bidirectional, Triple-Voltage DC-DC Converter for Hybrid and Fuel Cell Vehicle Power Systems
Electrical power systems in future hybrid and fuel cell vehicles may employ three voltage (14V, 42V and high voltage (HV)) nets. These will be necessary to accommodate existing 14V loads as well as efficiently handle new heavy loads at the 42V net and an electrical traction drive on the HV bus. A low-cost bi-directional dc-dc converter was proposed in (10) for connecting the three voltage nets. The converter consists of two half-bridges and a high-frequency transformer; thus minimizing the number of switching devices and their associated gate driver components. One salient feature is that the half-bridge on the 42V bus is also utilized to provide the 14V bus by operating its duty ratio around an atypical value of 1/3. This eliminates the need for an additional 14V/42V converter. Moreover, it makes use of the parasitic capacitance of the switches and the transformer leakage inductance for soft-switching; no extra active switches or passive resonant components are required. The use of half-bridges makes the topology suitable for interleaved multi-phase configurations as a means to increase the power level because the capacitor legs can be shared. This paper presents simulation and experimental results on an interleaved two-phase arrangement rated at 4.5 kW. Also discussed are the benefits of operating with the atypical duty ratio on the transformer and a preferred multi-phase configuration to minimize capacitor ripple currents.
Plant Support Engineering: Aging Management Program Development Guidance for AC and DC Low-Voltage Power Cable Systems for Nuclear P ower Plants
Regulatory and management concern regarding the reliability of low-voltage power cable systems at nuclear plants has been increasing for the past 5�10 years. The staff of the United States Nuclear Regulatory Commission are concerned that wetted (up to and including submergence) low-voltage power cable circuits may be degrading to the point at which multiple cable circuits may fail when called on to perform functions affecting safety. Utility managers are concerned that cables may fail, causing adverse sa...
Voltage and Power Stability of HVDC Systems � Emerging Issues and New Analytical Methodologies
Traditionally HVDC links have been built as single pointto-point AC/DC interconnections, or single-infeed HVDC systems as they are commonly known. However in recent years, as the use of HVDC transmission continues to develop situations have arisen where multiple HVDC links terminate in close proximity in a common AC system area. These emerging system configurations, generally known as multi-infeed HVDC systems, are particularly inherent in regional power systems predominantly interconnected by HVDC links. Already such configurations are apparent in the Scandinavian and North European power system interconnection. Elsewhere in rapidly industrializing regions such as South America and the ASEAN (Association of South East Asian Nations), multi-infeed HVDC systems potentially
Denis Lee; Hau Aik; G�ran Andersson
Investigations of grid-connected wind power system : low voltage ride through and power quality issues.
??This thesis presents an investigation on system architecture, control and analysis of wind turbine generators to improve grid integration performance. First of all, the main� (more)
Zhang, Shao.
Impact of Wind Power Plants on Voltage and Transient Stability of Power Systems
A standard three-machine, nine-bus wind power system is studied and augmented by a radially connected wind power plant that contains 22 wind turbine generators.
Muljadi, E.; Nguyen, Tony B.; Pai, M. A.
??Our interconnected electric power system is presently facing many challenges that it was not originally designed and engineered to handle. The increased interarea power transfers,� (more)
Nguyen, Cuong Phuc
Voltage quality behaviour of a wind turbine based Remote Area Power System
The power quality behaviour of a Remote Area Power System (RAPS) consisting of a Doubly Fed Induction Generator (DFIG), its main loads and a dummy load is presented in this paper. The dummy load is used to maintain the power balance of the system under ...
Nishad Mendis; Kashem M. Muttaqi; Sarath Perera
efficient usage of the main bank energy; as much as 50% iselectrolytic capacitor bank stored energy system. in Fig. 5,bank modules). Thorough sources. tests to determine stored-energy
Investigation of decision trees (DTs) parameters for power system voltage stability enhancement
This paper describes the application of Decision Tress (DTs) in order to specify the most critical location and the rate of series compensation in order to increase power system loading margin. The proposed methodology is applied to a projected model ...
Eirini A. Leonidaki; Nikos D. Hatziargyriou
High Voltage Thermal Battery Reliability Required to Equal Inverter-Converter Systems
MC-583 and XMC-650 circuits, including associated pulse transformers, are compare with the inverter-converter system typical of present fuses. The required probabilities of thermal battery shorts and opens are determined.
Power system voltage stability and agent based distribution automation in smart grid
Our interconnected electric power system is presently facing many challenges that it was not originally designed and engineered to handle. The increased inter-area power transfers, aging infrastructure, and old technologies, have caused many problems ...
Cuong Phuc Nguyen / Alexander J. Flueck
Systems and methods for reducing transient voltage spikes in matrix converters
Systems and methods are provided for delivering energy using an energy conversion module that includes one or more switching elements. An exemplary electrical system comprises a DC interface, an AC interface, an isolation module, a first conversion module between the DC interface and the isolation module, and a second conversion module between the AC interface and the isolation module. A control module is configured to operate the first conversion module to provide an injection current to the second conversion module to reduce a magnitude of a current through a switching element of the second conversion module before opening the switching element.
Kajouke, Lateef A.; Perisic, Milun; Ransom, Ray M.
Impacts of Large-Scale Wind Generators Penetration on the Voltage Stability of Power Systems
by 2020 and 300 GW of installed wind power capacity in Europe by 2030. An overview of the historical to make energy available economically with reduced carbon emission using renewable energy sources-limiting factor. FACTS controllers have been used for solving various power system steady-state control problems
Specifying a Low-Voltage Dynamic Sag Corrector
Voltage sags are the most frequent and costly of power quality problems for industrial customers. A number of non-battery-based technologies have emerged in the market to mitigate the effects of voltage sags on industrial processes. Among these, the low-voltage dynamic sag corrector (DySC) can provide ride-through during sags to 50 percent of nominal voltage for up to 12 cycles with no energy storage; for longer ride-through or deeper sags, energy storage capacitors are available as an option. This repor...
Decision support system for estimating the technically and economically exploitable renewable energy sources potential in wide areas for connection to high voltage networks
A decision support information system for estimating the technically and economically exploitable renewable energy sources (RES) potential in wide areas is presented in this paper. The system estimates the RES potential in specific areas, examines ... Keywords: DSS, GIS, biomass, decision support systeoms, distributed generation, geographical information systems, high voltage network, renewable energy estimation, renewable energy forecasting, renewable energy potential, renewable energy sources, small hydro, wind energy, wind power
Michael Psalidas; Demosthenes Agoris; Vassilis Kilias; Kostas Tigas; Panagiotis Stratis; Giannis Vlachos
RECIPIENT:Princeton Power Systems STATE: NJ PROJECT Marine High-Voltage Power Conditioning and Transmission System with Integrated Energy Storage
Princeton Power Systems Princeton Power Systems STATE: NJ PROJECT Marine High-Voltage Power Conditioning and Transmission System with Integrated Energy Storage TITLE: Funding Opportunity Announcement Number Procurement Instrument Number NEPA Control Number cm Number DE-FOA-0000293 DE-EE0003640 GFO-000364~001 GOO Based on my review of the information concerning the proposed action, as NEPA Compliance Officer (authorized under DOE Order 451.1A), I have made the foUowing determination: CX, EA, EIS APPENDIX AND NUMBER: Description: A9 Information gathering (including, but not limited to, ~terature surveys, inventories, audits), data analysis (including computer modeling), document preparation (such as conceptual design or feasibility studies, analytical energy supply
Testing and Analysis for Lifetime Prediction of Crystalline Silicon PV Modules Undergoing Degradation by System Voltage Stress: Preprint
Acceleration factors are calculated for crystalline silicon PV modules under system voltage stress by comparing the module power during degradation outdoors to that in accelerated testing at three temperatures and 85% relative humidity. A lognormal analysis is applied to the accelerated lifetime test data considering failure at 80% of the initial module power. Activation energy of 0.73 eV for the rate of failure is determined, and the probability of module failure at an arbitrary temperature is predicted. To obtain statistical data for multiple modules over the course of degradation in-situ of the test chamber, dark I-V measurements are obtained and transformed using superposition, which is found well suited for rapid and quantitative evaluation of potential-induced degradation. It is determined that shunt resistance measurements alone do not represent the extent of power degradation. This is explained with a two-diode model analysis that shows an increasing second diode recombination current and ideality factor as the degradation in module power progresses. Failure modes of the modules stressed outdoors are examined and compared to those stressed in accelerated tests.
Hacke, P.; Smith, R.; Terwiliger, K.; Glick, S.; Jordan, D.; Johnston, S.; Kempe, M.; Kurtz, S.
Unlikely Combination of Experiments With a Novel High-Voltage CIGS Photovoltaic Array: Preprint
A new high-voltage array comprising bipolar strings of copper indium gallium diselenide (CIGS) photovoltaic (PV) modules was inaugurated in 2005. It is equipped with a unique combination of tests, which likely have never before been deployed simultaneously within a single array: full current-voltage (I-V) traces, high-voltage leakage current measurements, and peak-power tracking or temporal stepped-bias profiling. The array nominally produces 1 kW power at 1 sun. The array's electrical characteristics are continuously monitored and controlled with a programmable electronic load interfaced to a data acquisition system (DAS), that also records solar and meteorological data. The modules are mounted with their frames electrically isolated from earth ground, in order to facilitate measurement of the leakage currents that arise between the high voltage bias developed in the series-connected cells and modules and their mounting frames. Because the DAS can perform stepped biasing of the array as a function of time, synchronous detection of the leakage current data with alternating bias is available. Leakage current data and their dependence on temperature and voltage are investigated. Array power data are analyzed across a wide range of varying illuminations and temperatures from the I-V traces. Array performance is also analyzed from an energy output perspective using peak-power tracking data.
del Cueto, J. A.; Sekulic, B. R.
Abstract--Power system currents and voltages magnitudes are time variant due to continual changes in system configuration
corresponding matrix form. Another possible application is the forecasting of the electrical signals behavior changes in system configuration and load conditions. This paper deals with the statistical description of measured electrical signals. A matrix representation is chosen in order to preserve the information about
Paris-Sud XI, Université de
Modular high voltage power supply for chemical analysis
A high voltage power supply for use in a system such as a microfluidics system, uses a DC-DC converter in parallel with a voltage-controlled resistor. A feedback circuit provides a control signal for the DC-DC converter and voltage-controlled resistor so as to regulate the output voltage of the high voltage power supply, as well as, to sink or source current from the high voltage supply.
Stamps, James F. (Livermore, CA); Yee, Daniel D. (Dublin, CA)
A high voltage power supply for use in a system such as a microfluidics system, uses a DC--DC converter in parallel with a voltage-controlled resistor. A feedback circuit provides a control signal for the DC--DC converter and voltage-controlled resistor so as to regulate the output voltage of the high voltage power supply, as well as, to sink or source current from the high voltage supply.
PQ Encyclopedia: Understanding Voltage Unbalance
This PQ Encyclopedia examines voltage unbalance, methods to calculate line voltages and the degree of voltage unbalance, and mitigation techniques.
Aviation Management Professional Award Nomination for:
Professional Nomination for Professional Nomination for Managerial/Official Award: Joseph M. Ginanni Aviation Manager US Department of Energy/National Nuclear Security Administration, Nevada Site Office Bio Joseph M. Ginanni Aviation Manager National Nuclear Security Administration Nevada Site Office Mr. Ginanni has worked for the Nevada Site Office (NSO) since 1991. For the past five years, he has served as the NSO Aviation Manager, managing and overseeing the Management and Operating contractor's aviation services department and their operation and maintenance of NSO's five aircraft (3 Beechcraft King Airs and 2 Bell 412s) which are stationed at both Nellis AFB, NV and Andrews AFB, MD. Prior to his position as Aviation Manager, he was the team leader for the Radioactive Waste
A device is described for providing a source of molecular ions having a large output current and with an accelerated energy of the order of 600 kv. Ions are produced in an ion source which is provided with a water-cooled source grid of metal to effect maximum recombination of atomic ions to molecular ions. A very high accelerating voltage is applied to withdraw and accelerate the molecular ions from the source, and means are provided for dumping the excess electrons at the lowest possible potentials. An accelerating grid is placed adjacent to the source grid and a slotted, grounded accelerating electrode is placed adjacent to the accelerating grid. A potential of about 35 kv is maintained between the source grid and accelerating grid, and a potential of about 600 kv is maintained between the accelerating grid and accelerating electrode. In order to keep at a minimum the large number of oscillating electrons which are created when such high voltages are employed in the vicinity of a strong magnetic field, a plurality of high voltage cascaded shields are employed with a conventional electron dumping system being employed between each shield so as to dump the electrons at the lowest possible potential rather than at 600 kv.
Luce, J.S.
A method for calculation of margins to voltage instability applied on the Norwegian system for maintaining required security level
The paper describes a method for calculating margins to voltage instability. The method is based on sensitivity techniques. The measure to voltage instability can be given in terms of MW, MVAr or MVA depending on the components in the increase in load. The extensions to earlier publications of the method are the ability to increase the load and generation simultaneously on several buses without increasing the computation time. A single forward and backward substitution is sufficient to find the required sensitivities when the load is increased. The productions of the plant can be increased either by a specified profile or by using the turbine droop characteristics. A method for identification of contingencies needing an explicit reserve evaluation is briefly described.
Flataboe, N.; Fosso, O.B.; Ognedal, R.; Carlsen, T.; Heggland, K.R.
Price of Cameron, LA Natural Gas LNG Imports (Nominal Dollars...
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(Nominal Dollars per Thousand Cubic Feet) Price of Cameron, LA Natural Gas LNG Imports (Nominal Dollars per Thousand Cubic Feet) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5...
This patent relates to high voltage supply circuits adapted for providing operating voltages for GeigerMueller counter tubes, and is especially directed to an arrangement for maintaining uniform voltage under changing conditions of operation. In the usual power supply arrangement for counter tubes the counter voltage is taken from across the power supply output capacitor. If the count rate exceeds the current delivering capaciiy of the capacitor, the capacitor voltage will drop, decreasing the counter voltage. The present invention provides a multivibrator which has its output voltage controlled by a signal proportional to the counting rate. As the counting rate increases beyond the current delivering capacity of the capacitor, the rectified voltage output from the multivibrator is increased to maintain uniform counter voltage.
Zito, G.V.
Impact of the Voltage Transients after a Fast Power Abort on the Quench Detection System in the LHC Main Dipole Chain
A Fast Power Abort in the LHC superconducting main dipole circuit consists in the switch-off of the power converter and the opening of the two energy-extraction switches. Each energy-extraction unit is composed of redundant electromechanical breakers, which are opened to force the current through an extraction resistor. When a switch is opened arcing occurs in the switch and a voltage of up to 1 kV builds up across the extraction resistor with a typical ramp rate of about 80 kV/s. The subsequent voltage transient propagates through the chain of 154 dipoles and superposes on the voltage waves caused by the switch-off of the power converter. The resulting effect caused intermittent triggering of the quench protection systems along with heater firings in the magnets when the transient occurred during a ramp of the current. A delay between power converter switch-off and opening of the energy-extraction switches was introduced to prevent this effect. Furthermore, the output filters of the power converters were mod...
Ravaioli, E; Formenti, F; Montabonnet, V; Pojer, M; Schmidt, R; Siemko, A; Solfaroli Camillocci, A; Steckert, J; Thiesen, H; Verweij, A
Automatic voltage imbalance detector
A device for indicating and preventing damage to voltage cells such as galvanic cells and fuel cells connected in series by detecting sequential voltages and comparing these voltages to adjacent voltage cells. The device is implemented by using operational amplifiers and switching circuitry is provided by transistors. The device can be utilized in battery powered electric vehicles to prevent galvanic cell damage and also in series connected fuel cells to prevent fuel cell damage.
Bobbett, Ronald E. (Los Alamos, NM); McCormick, J. Byron (Los Alamos, NM); Kerwin, William J. (Tucson, AZ)
Dynamic Voltage Regulation Using Distributed Energy Resources
Many distributed energy resources (DE) are near load centres and equipped with power electronics converters to interface with the grid, therefore it is feasible for DE to provide ancillary services such as voltage regulation, nonactive power compensation, and power factor correction. A synchronous condenser and a microturbine with an inverter interface are implemented in parallel in a distribution system to regulate the local voltage. Voltage control schemes of the inverter and the synchronous condenser are developed. The experimental results show that both the inverter and the synchronous condenser can regulate the local voltage instantaneously, while the dynamic response of the inverter is faster than the synchronous condenser; and that integrated voltage regulation (multiple DE perform voltage regulation) can increase the voltage regulation capability, increase the lifetime of the equipment, and reduce the capital and operation costs.
Xu, Yan [ORNL; Rizy, D Tom [ORNL; Li, Fangxing [ORNL; Kueck, John D [ORNL
Low voltage ride-through capability improvement of wind power generation using dynamic voltage restorer
Recently, the total amount of generation from wind power plants has been increased all over the world. In this situation, a large amount of disconnection of wind generation may give a serious influence in the power system. Consequently, Low Voltage Ride-Through ... Keywords: dynamic voltage restorer, energy storage, fault ride-through, fixed-speed induction generator, low voltage ride-through, voltage sag, wind power generation
Naohiro Hasegawa; Teruhisa Kumano
Automated Voltage Control in LHCb
LHCb is one of the 4 LHC experiments. In order to ensure the safety of the detector and to maximize efficiency, LHCb needs to coordinate its own operations, in particular the voltage configuration of the different subdetectors, according to the accelerator status. A control software has been developed for this purpose, based on the Finite State Machine toolkit and the SCADA system used for control throughout LHCb (and the other LHC experiments). This software permits to efficiently drive both the Low Voltage (LV) and High Voltage (HV) systems of the 10 different sub-detectors that constitute LHCb, setting each sub-system to the required voltage (easily configurable at run-time) based on the accelerator state. The control software is also responsible for monitoring the state of the Sub-detector voltages and adding it to the event data in the form of status-bits. Safe and yet flexible operation of the LHCb detector has been obtained and automatic actions, triggered by the state changes of the ...
Granado Cardoso, L; Jacobsson, R
Constant voltage ultracapacitor
Ultracapacitors have attracted lots of attention recently due to their growing use in hybrid vehicles and in energy storage applications for the smart grid. A very undesirable feature of ultracapacitors is the fact that the voltage drops as the capacitor is discharged. DC-DC converters are employed at present to convert the voltage of the ultracapacitor to constant voltage; however
Ezzat G. Bakhoum
Definition: Operating Voltage | Open Energy Information
Voltage Voltage Jump to: navigation, search Dictionary.png Operating Voltage The voltage level by which an electrical system is designated and to which certain operating characteristics of the system are related; also, the effective (root-mean-square) potential difference between any two conductors or between a conductor and the ground. The actual voltage of the circuit may vary somewhat above or below this value.[1] Related Terms system References ↑ Glossary of Terms Used in Reliability Standards An LikeLike UnlikeLike You like this.Sign Up to see what your friends like. inline Glossary Definition Retrieved from "http://en.openei.org/w/index.php?title=Definition:Operating_Voltage&oldid=480559" Categories: Definitions ISGAN Definitions What links here Related changes
Ancillary service details: Voltage control
Voltage control is accomplished by managing reactive power on an alternating-current power system. Reactive power can be produced and absorbed by both generation and transmission equipment. Reactive-power devices differ substantially in the magnitude and speed of response and in their capital costs. System operators, transmission owners, generators, customers, power marketers, and government regulators need to pay close attention to voltage control as they restructure the U.S. electricity industry. Voltage control can affect reliability and commerce in three ways: (1) Voltages must be maintained within an acceptable range for both customer and power-system equipment to function properly. (2) The movement of reactive power consumes transmission resources, which limits the ability to move real power and worsens congestion. (3) The movement of reactive power results in real-power losses. When generators are required to supply excessive amounts of reactive power, their real-power production must be curtailed. These opportunity costs are not currently compensated for in most regions. Current tariffs are based on embedded costs. These embedded-cost tariffs average about $0.51/MWh, equivalent to $1.5 billion annually for the United States as a whole. Although this cost is low when compared with the cost of energy, it still aggregates to a significant amount of money. This report takes a basic look at why the power system requires reactive power (an appendix explains the fundamentals of real and reactive power). The report then examines the various types of generation and transmission resources used to supply reactive power and to control voltage. Finally it discusses how these resources are deployed and paid for in several reliability regions around the country. As the U.S. electricity industry is restructured, the generation, transmission, and system-control equipment and functions that maintain voltages within the appropriate ranges are being deintegrated.
Kirby, B.; Hirst, E.
Low power, scalable multichannel high voltage controller
A low voltage control circuit is provided for individually controlling high voltage power provided over bus lines to a multitude of interconnected loads. An example of a load is a drive for capillary channels in a microfluidic system. Control is distributed from a central high voltage circuit, rather than using a number of large expensive central high voltage circuits to enable reducing circuit size and cost. Voltage is distributed to each individual load and controlled using a number of high voltage controller channel switches connected to high voltage bus lines. The channel switches each include complementary pull up and pull down photo isolator relays with photo isolator switching controlled from the central high voltage circuit to provide a desired bus line voltage. Switching of the photo isolator relays is further controlled in each channel switch using feedback from a resistor divider circuit to maintain the bus voltage swing within desired limits. Current sensing is provided using a switched resistive load in each channel switch, with switching of the resistive loads controlled from the central high voltage circuit.
Stamps, James Frederick (Livermore, CA); Crocker, Robert Ward (Fremont, CA); Yee, Daniel Dadwa (Dublin, CA); Dils, David Wright (Fort Worth, TX)
Optimal Compensation Algorithms for a Dynamic Voltage Restorer
The Dynamic Voltage Restorer (DVR) as an electronics based custom device, is used to protect sensitive loads from the voltage sags in the power distribution system. With the rapid technology advancement in industrial control processes, it is experiencing ... Keywords: Dynamic Voltage Restorer (DVR), power quality, voltage sag, Zero Active Power Compensation (ZAPC), Minimal Active Power Compensation (MAPC)
Deng Pan; Chen Zhongming; Jiang Peng; Abdelkrim Benchaib; Guillaume De Preville
JEFF LANE, NOMINEE TO BE AN ASSISTANT JEFF LANE, NOMINEE TO BE AN ASSISTANT SECRETARY OF ENERGY, CONGRESSIONAL AND INTERGOVERNMENTAL AFFAIRS, DEPARTMENT OF ENERGY MARCH 17, 2010 Chairman Bingaman, Ranking Member Murkowski, and distinguished Members of the Committee, it is an honor and a privilege to appear before you today as President Obama's nominee for Assistant Secretary of Energy for Congressional and Intergovernmental Affairs. I want to thank Secretary Chu for recommending me to the President and thank the Committee for holding this hearing. As you consider my nomination for this position, I hope you will take into account my record, my experiences and my commitment of service to the Congress and to the important mission of the Department of Energy. I have spent most of my professional life - almost 16 years - serving in senior staff positions in
NREL: Measurements and Characterization - Current Versus Voltage
Current Versus Voltage Current Versus Voltage The National Renewable Energy Laboratory (NREL) Device Performance group uses current versus voltage (I-V) measurement systems to assess the main performance parameters for photovoltaic (PV) cells and modules. I-V measurement systems determine the output performance of devices, including: open-circuit voltage (Voc), short-circuit current (Isc), fill factor (FF), maximum power output of the device (Pmax), voltage at maximum power (Vmax), current at maximum power (Imax), and conversion efficiency of the device (η). Some I-V systems may also be used to perform dark I-V measurements to determine diode properties and series and shunt resistances. We use three I-V systems to measure performance of individual PV cells; and four for modules - two for measurements under simulated conditions; and
DOE General Counsel Nomination Announcement | Department of Energy
General Counsel Nomination Announcement General Counsel Nomination Announcement DOE General Counsel Nomination Announcement March 18, 2009 - 12:00am Addthis WASHINGTON, DC - Today, President Barack Obama announced his intent to nominate the following individuals to key administration posts: Susan Burk, Special Representative of the President, with the rank of Ambassador, State Department; Raphael Bostic, Assistant Secretary for Policy Development and Research, Department of Housing and Urban Development; Michelle J. DePass, Assistant Administrator for International Affairs, Environmental Protection Agency; Cynthia J. Giles, Assistant Administrator for Enforcement and Compliance Assurance, Environmental Protection Agency; Michael L. Connor, Director, Bureau of Reclamation, Department of the Interior; Scott Blake
Optimization Online - Validation of Nominations in Gas Network ...
Nov 30, 2012... the validation of nomination problem: Given a gas transmission network consisting of passive pipelines and active, controllable elements and�...
NETL: News Release - DOE Opens Nomination Process for 2002 Homer...
Nomination Process For 2002 Homer Lowry Award Award Honors Outstanding Achievement By Fossil Fuels Scientist or Engineer WASHINGTON, DC - Homer H. Lowry Award The U.S....
A Review Of Water Contents Of Nominally Anhydrous Natural Minerals...
A Review Of Water Contents Of Nominally Anhydrous Natural Minerals In The Mantles Of Earth, Mars And The Moon Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal...
Optical voltage reference
An optical voltage reference for providing an alternative to a battery source. The optical reference apparatus provides a temperature stable, high precision, isolated voltage reference through the use of optical isolation techniques to eliminate current and impedance coupling errors. Pulse rate frequency modulation is employed to eliminate errors in the optical transmission link while phase-lock feedback is employed to stabilize the frequency to voltage transfer function.
Rankin, R.; Kotter, D.
An optical voltage reference for providing an alternative to a battery source is described. The optical reference apparatus provides a temperature stable, high precision, isolated voltage reference through the use of optical isolation techniques to eliminate current and impedance coupling errors. Pulse rate frequency modulation is employed to eliminate errors in the optical transmission link while phase-lock feedback is employed to stabilize the frequency to voltage transfer function. 2 figures.
Automated Voltage Standard Ready
... �We wanted a standard that was ... as envisioned, then within our lifetimes there will no longer be a need for voltage transfer standards that have to be ...
Substation voltage upgrading
This report addresses specific issues to support sound yet not unduly conservative uprating practices for substations. The main parts of the report cover the insulation withstand and overvoltage protection aspects, environmental measurements, reliability criteria, and industry experience. First the insulation design concerns are addressed. Substation stress by a backflashover of the line insulation due to lightning in the vicinity of the substation is recognized as a critical stress. A representative part of a 550 kV BIL substation was erected at the EPRI High Voltage Transmission Research Center, where also a special test circuit was assembled to produce a fast front, slow tail (0.2/200 {mu}s) wave. The substation as well as some special configurations were tested for line-to-ground and line-to-line withstand. Computer studies were performed to complement the test results. A number of important conclusions was reached. The most prominent result in that the high frequency oscillations, as caused by reflections within the substation, do not effect the Critical Flashover Voltage (CFO). The present practice, based on the highest peak is therefore very conservative. The slow tail of the wave appears to dictate the CFO. An arrester model for computer studies to represent very fast as well as slow phenomena was derived. It is based on full scale arrester test data, made available in this project. The computer program to calculate arrester model parameters is also a part of the report. The electric environmental measurements are reported for the tested substation at the HVTRC and for the uprated substation of Public Service Company of Colorado, both before and after the uprating. The performance is satisfactory when corona free hardware is used. Insulation design criteria are analyzed based on substation reliability, the system viewpoint and consequences of the failure. Utility experience with uprated substations is reviewed.
Panek, J.; Elahi, H.; Lux, A.; Imece, A.F. (General Electric Co., Schenectady, NY (United States). Power Systems Engineering Dept.); LaPanse, R.A.; Stewart, J.R. (Public Service Co. of Colorado, Denver, CO (United States))
Voltage Stability Studies for Southern Company Services
This report describes a study conducted under an EPRI Tailored Collaboration project to develop and demonstrate procedures for the assessment of voltage security of the Southern Electric System (SES). The contractor used EPRI steady-state analysis tools including VSTAB (Voltage STABility assessment program) to assess stability margins and verified them using EPRI dynamic tools including ETMSP (Extended Transient / Mid-term Stability Program).
Dynamic characteristics of an orthogonal turbine and output-control systems for TPP with high-voltage frequency converter
A mathematical description of a closed control system with allowance for pressure fluctuations in the head system, which makes it possible to analyze the regime stability of orthogonal generating sets at tidal electric power plants when operating in the complete range of heads, outputs, and rotational speeds, and to select parameters of the control system, is obtained for an orthogonal hydroturbine and a generator with a load regulator.
Berlin, V. V.; Murav'ev, O. A.; Golubev, A. V.
A Nominal Filter for Web Search Snippets: Using the Web to Identify Members of Latin
A Nominal Filter for Web Search Snippets: Using the Web to Identify Members of Latin America. This paper presents efforts aimed at using Natural Language Engineering (NLE) techniques to solve of three Latin American countries: Uruguay, Argentina and Colombia. An NLE system is under construction
Turner, William
Physical design with multiple on-chip voltages
Supply voltage is one of the dominant factors that determine the timing performance and power consumption of VLSI chips. For digital systems with a single supply voltage, some logic devices typically operate faster or more frequently than necessary, ...
Chunhong Chen
Reactive Power Management to Address Short-Term Voltage Stability Using Optimal Reactive Power Allocation Method
Voltage stability has attracted attention recently because power systems are increasingly operated under heavy loads and subjected to high levels of dynamic fast acting loads. Voltage instability under these conditions can be manifested as depressed voltage profiles, delayed voltage recovery at load buses following a major disturbance, and even fast voltage collapse. Single-phase, low-inertia induction motors can have adverse effect on voltage stability as they decelerate in the event of voltage ...
Linear modeling and simulation of low-voltage electric system for single-point vulnerability assessment of military installation
This paper describes the formulation and development of a linear model to support the single-point vulnerability assessment of electric distribution systems at existing and future U.S. Department of Defense (DoD) military sites. The model uses flow sensitivity ...
Edgar C. Portante; Thomas N. Taxon; James A. Kavicky; Tarek Abdallah; Timothy K. Perkins
Substation voltage uprating, i.e., conversion of a substation from a lower rated voltage to a higher rated voltage without a complete substation rebuild, can lead to excellent economic benefits. Utilization of the old substation layout and/or the existing equipment, to some extent, is the practical objective of such an uprating. The objective of this project was to assess the opportunities for substation uprating in the industry, to establish feasibility for such uprating and to study methods for accomplishing it. The final aim of the project was to provide guidance to utilities interested in uprating. 56 refs., 41 figs., 18 tabs.
Panek, J.; Elahi, H.; Sublich, M. (General Electric Co., Schenectady, NY (USA). Systems Development and Engineering Dept.)
Voltage Quality Improvement Using DVR
The problem of voltage sags and Swells and its severe impact on sensitive loads is well known. To solve this problem, custom power devices are used. One of those devices is the Dynamic Voltage Restorer (DVR), which is one of the most efficient and effective ... Keywords: Dynamic Voltage Restorer (DVR), Voltage sags, Voltage swells, Custom power, Power Quality
M. Arun Bhaskar; S. S. Dash; C. Subramani; M. Jagadeesh Kumar; P. R. Giresh; M. Varun Kumar
High voltage photovoltaic power converter
An array of independently connected photovoltaic cells on a semi-insulating substrate contains reflective coatings between the cells to enhance efficiency. A uniform, flat top laser beam profile is illuminated upon the array to produce electrical current having high voltage. An essentially wireless system includes a laser energy source being fed through optic fiber and cast upon the photovoltaic cell array to prevent stray electrical signals prior to use of the current from the array. Direct bandgap, single crystal semiconductor materials, such as GaAs, are commonly used in the array. Useful applications of the system include locations where high voltages are provided to confined spaces such as in explosive detonation, accelerators, photo cathodes and medical appliances.
Haigh, Ronald E. (Arvada, CO); Wojtczuk, Steve (Cambridge, MA); Jacobson, Gerard F. (Livermore, CA); Hagans, Karla G. (Livermore, CA)
Superconducting Low Voltage Direct Current (LVDC) Networks
A low voltage dc superconducting distribution network is a challenging future opportunity for power distribution. This report presents a scheme for a superconducting, parallel- connected, multiterminal dc transmission system.
Assessment of Voltage Security Methods and Tools
To ensure voltage-secure operation of a power system, VAR control devices must be optimally placed and operated. This project assessed tools and methods that claim to help utilities meet these needs and recommended specific enhancements to these tools.
? Adjustable Output Voltage
The LM25010 features all the functions needed to implement a low cost, efficient, buck regulator capable of supplying in excess of 1A load current. This high voltage regulator integrates an N-Channel Buck Switch, and is available in thermally enhanced LLP-10 and TSSOP-14EP packages. The constant on-time regulation scheme requires no loop compensation resulting in fast load transient response and simplified circuit implementation. The operating frequency remains constant with line and load variations due to the inverse relationship between the input voltage and the on-time. The valley current limit detection is set at 1.25A. Additional features include: VCC under-voltage lock-out, thermal shutdown, gate drive under-voltage lock-out, and maximum duty cycle limiter.
Lmq Is Aec-q Grade
Current-Voltage and Capacitance-Voltage characteristics of Pd ...
Presentation Title, Current-Voltage and Capacitance-Voltage characteristics of Pd ... Nonlocal Modeling in High Rate Deformation and Ductile Fracture of�...
Centralized wind power plant voltage control with optimal power flow algorithm.
??This thesis presents a method of controlling the reactive power injected into a medium-voltage collection system by multiple wind turbine generators such that the voltage� (more)
Kline, Jared Andrew
Corona and Motor Voltage Interim Report
It has been suggested that to meet the FreedomCAR objectives for cost, size, weight, efficiency, and reliability higher buss voltages be utilized in HEV and FC automotive applications. The reasoning is that since electric power is equal to the product of voltage and current for a given power a higher voltage and lower current would result in smaller cable and inverter switching components. Consequently, the system can be lighter and smaller. On the other hand, higher voltages are known to require better and thicker electrical insulation that reduce the available slot area for motor windings. One cause of slow insulation breakdown is corona that gradually erodes the insulation and shortens the life expectancy of the motor. This study reports on the results of a study on corona initiating voltages for mush-wound and bobbin-wound stators. A unique testing method is illustrated.
Hsu, J.S.
High voltage DC power supply
A high voltage DC power supply having a first series resistor at the output for limiting current in the event of a short-circuited output, a second series resistor for sensing the magnitude of output current, and a voltage divider circuit for providing a source of feedback voltage for use in voltage regulation is disclosed. The voltage divider circuit is coupled to the second series resistor so as to compensate the feedback voltage for a voltage drop across the first series resistor. The power supply also includes a pulse-width modulated control circuit, having dual clock signals, which is responsive to both the feedback voltage and a command voltage, and also includes voltage and current measuring circuits responsive to the feedback voltage and the voltage developed across the second series resistor respectively. 7 figs.
Droege, T.F.
Low-voltage gyrotrons
For a long time, the gyrotrons were primarily developed for electron cyclotron heating and current drive of plasmas in controlled fusion reactors where a multi-megawatt, quasi-continuous millimeter-wave power is required. In addition to this important application, there are other applications (and their number increases with time) which do not require a very high power level, but such issues as the ability to operate at low voltages and have compact devices are very important. For example, gyrotrons are of interest for a dynamic nuclear polarization, which improves the sensitivity of the nuclear magnetic resonance spectroscopy. In this paper, some issues important for operation of gyrotrons driven by low-voltage electron beams are analyzed. An emphasis is made on the efficiency of low-voltage gyrotron operation at the fundamental and higher cyclotron harmonics. These efficiencies calculated with the account for ohmic losses were, first, determined in the framework of the generalized gyrotron theory based on the cold-cavity approximation. Then, more accurate, self-consistent calculations for the fundamental and second harmonic low-voltage sub-THz gyrotron designs were carried out. Results of these calculations are presented and discussed. It is shown that operation of the fundamental and second harmonic gyrotrons with noticeable efficiencies is possible even at voltages as low as 5-10 kV. Even the third harmonic gyrotrons can operate at voltages about 15 kV, albeit with rather low efficiency (1%-2% in the submillimeter wavelength region).
Glyavin, M. Yu.; Zavolskiy, N. A.; Sedov, A. S. [Institute of Applied Physics RAS, N. Novgorod 603600 (Russian Federation); Nusinovich, G. S. [IREAP, University of Maryland, College Park, Maryland 20742-3511 (United States)
Comparative High Voltage Impulse Measurement
... substrate and surrounded by insulating oil; the low ... the amplitudes of the voltage peaks that are ... The uncertainties in the peak output voltages for the ...
A Multiattribute Utility Analysis of Sites Nominated For Characterization
A Multiattribute Utility Analysis of Sites Nominated For A Multiattribute Utility Analysis of Sites Nominated For Characterization For the First Radioactive Waste Repository - A Decision Aiding Methodology A Multiattribute Utility Analysis of Sites Nominated For Characterization For the First Radioactive Waste Repository - A Decision Aiding Methodology Summary In December 1984, the Department of Energy (DOE) published draft environmental assessments (EAs) to support the proposed nomination of five sites and the recommendation of three sites for characterization for the first radioactive-waste repository. A chapter common to all the draft EAs (Chapter 7) presented rankings of the five sites against the postclosure and the preclosure technical siting guidelines. To determine which three sites appeared most favorable for recommendation for characterization,
DOE Under Secretary Nomination Announcement | Department of Energy
Under Secretary Nomination Announcement Under Secretary Nomination Announcement DOE Under Secretary Nomination Announcement March 12, 2009 - 12:00am Addthis WASHINGTON, DC - Today, President Barack Obama announced his intent to nominate the following individuals to key administration posts: Demetrios Marantis, Nominee for Deputy United States Trade Representative; Kristina M. Johnson, Nominee for Under Secretary of Energy; Gina McCarthy, Nominee for Assistant Administrator for Air and Radiation, Environmental Protection Agency; and Ronald H. Weich, Nominee for Assistant Attorney General, Office of Legislative Affairs, Department of Justice. President Obama said, "Each of these individuals brings a unique talent and dedication to the causes we are tackling everyday in my administration. Together they bring decades of public service and diverse backgrounds that
Do parties still matter? : the politics of gubernatorial nominations
Who controls the nomination in gubernatorial elections? This dissertation seeks to answer this simple question. Parties have classically been the organizations held responsible for throwing their collective effort behind ...
Cobb, Rachael V
EERE News: President Obama Nominates New Energy Department and...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
New Energy Department and EPA Heads President Obama on March 4 nominated Ernest Moniz to replace Steven Chu as Secretary of Energy, and Gina McCarthy to take over U.S....
Nominate An Inspirational STEM Teacher for the Nation's Highest Honors |
Nominate An Inspirational STEM Teacher for the Nation's Highest Nominate An Inspirational STEM Teacher for the Nation's Highest Honors Nominate An Inspirational STEM Teacher for the Nation's Highest Honors February 8, 2013 - 1:04pm Addthis President Barack Obama talks with Presidential Awards for Excellence in Mathematics and Science Teaching winners in the State Dining of the White House January 6, 2010. (Official White House Photo by Chuck Kennedy) President Barack Obama talks with Presidential Awards for Excellence in Mathematics and Science Teaching winners in the State Dining of the White House January 6, 2010. (Official White House Photo by Chuck Kennedy) How can I participate? The 2013 Awards will honor mathematics and science (including computer science) teachers working in grades 7-12. Nominations close on
Agency Energy Coordinators for Award Nominations | Department of Energy
Agency Energy Coordinators for Award Nominations Agency Energy Coordinators for Award Nominations Agency Energy Coordinators for Award Nominations October 7, 2013 - 4:41pm Addthis Federal agency energy coordinators handle all nominations for the Federal Energy and Water Management Awards. Contact your agency energy coordinator well in advance of all award deadlines to learn about internal submission processes. Don Juhasz Defense Logistics Agency 703-767-3537 Jerard Butler General Services Administration 202-401-0855 Mark Ewing General Services Administration 202-708-9296 Wayne Thalasinos National Aeronautics and Space Administration 202-358-3811 Mark Sprouse National Archives and Records Administration 301-837-3019 David Hauk Smithsonian Institution 202-633-1537 Leslie Ford Social Security Administration 410-594-0111
Research of Dynamic Voltage Restorer Based on Repetitive Control Strategy
This paper introduces a dynamic voltage restorer with independent three-phase structure, which is controlled on repetitive control strategy. Computer simulation of the whole repetitive control system is performed by Matlab/Simulink, and the results show ... Keywords: Dynamic Voltage Restorer, Repetitive Control, Voltage Sag
Tianyu Liu
Device for monitoring cell voltage
A device for monitoring a rechargeable battery having a number of electrically connected cells includes at least one current interruption switch for interrupting current flowing through at least one associated cell and a plurality of monitoring units for detecting cell voltage. Each monitoring unit is associated with a single cell and includes a reference voltage unit for producing a defined reference threshold voltage and a voltage comparison unit for comparing the reference threshold voltage with a partial cell voltage of the associated cell. The reference voltage unit is electrically supplied from the cell voltage of the associated cell. The voltage comparison unit is coupled to the at least one current interruption switch for interrupting the current of at least the current flowing through the associated cell, with a defined minimum difference between the reference threshold voltage and the partial cell voltage.
Doepke, Matthias (Garbsen, DE); Eisermann, Henning (Edermissen, DE)
Electron launching voltage monitor
An electron launching voltage monitor measures MITL voltage using a relationship between anode electric field and electron current launched from a cathode-mounted perturbation. An electron launching probe extends through and is spaced from the edge of an opening in a first MITL conductor, one end of the launching probe being in the gap between the MITL conductor, the other end being adjacent a first side of the first conductor away from the second conductor. A housing surrounds the launching probe and electrically connects the first side of the first conductor to the other end of the launching probe. A detector detects the current passing through the housing to the launching probe, the detected current being representative of the voltage between the conductors.
Mendel, Clifford W. (Albuquerque, NM); Savage, Mark E. (Albuquerque, NM)
Voltage controlled current source
A seven decade, voltage controlled current source is described for use in testing intermediate range nuclear instruments that covers the entire test current range of from 10 picoamperes to 100 microamperes. High accuracy is obtained throughout the entire seven decades of output current with circuitry that includes a coordinated switching scheme responsive to the input signal from a hybrid computer to control the input voltage to an antilog amplifier, and to selectively connect a resistance to the antilog amplifier output to provide a continuous output current source as a function of a preset range of input voltage. An operator controlled switch provides current adjustment for operation in either a real-time simulation test mode or a time response test mode.
Casne, Gregory M. (Pittsburgh, PA)
High frequency breakdown voltage
This report contains information about the effect of frequency on the breakdown voltage of an air gap at standard pressure and temperature, 76 mm Hg and O{degrees}C, respectively. The frequencies of interest are 47 MHz and 60 MHz. Additionally, the breakdown in vacuum is briefly considered. The breakdown mechanism is explained on the basis of collision and ionization. The presence of the positive ions produced by ionization enhances the field in the gap, and thus determines the breakdown. When a low-frequency voltage is applied across the gap, the breakdown mechanism is the same as that caused by the DC or static voltage. However, when the frequency exceeds the first critical value f{sub c}, the positive ions are trapped in the gap, increasing the field considerably. This makes the breakdown occur earlier; in other words, the breakdown voltage is lowered. As the frequency increases two decades or more, the second critical frequency, f{sub ce}, is reached. This time the electrons start being trapped in the gap. Those electrons that travel multiple times across the gap before reaching the positive electrode result in an enormous number of electrons and positive ions being present in the gap. The result is a further decrease of the breakdown voltage. However, increasing the frequency does not decrease the breakdown voltage correspondingly. In fact, the associated breakdown field intensity is almost constant (about 29 kV/cm).The reason is that the recombination rate increases and counterbalances the production rate, thus reducing the effect of the positive ions` concentration in the gap. The theory of collision and ionization does not apply to the breakdown in vacuum. It seems that the breakdown in vacuum is primarily determined by the irregularities on the surfaces of the electrodes. Therefore, the effect of frequency on the breakdown, if any, is of secondary importance.
Chu, Thanh Duy
??Lithium-ion batteries are the most commonly chosen power source for many portable applications. Advantages like high energy density, high nominal voltage, less maintenance, and low� (more)
Annavajjula, Vamsi Krishna
Voltage Stability/Security Assessment and On-Line Control: Volumes 1-4
To address growing utility concerns of voltage instability and possible voltage collapse, EPRI has developed a new voltage stability analysis package for large power systems, VSTAB. This off-line planning tool provides information on a utility power system's proximity to and mechanism of voltage instability.
Operating standby redundant controller to improve voltage source inverter reliability .
??This thesis presents a control architecture that achieves operating standby redundancy for a voltage source inverter controller. The system was designed to increase reliability by� (more)
Blevins, Stephen T.
8, 2009 8, 2009 Good morning, Mr. Chairman, Senator McCain, members of the Committee. It is a great honor to appear before you today as President Obama's nominee to be the Assistant Secretary for Environmental Management at the United States Department of Energy. I thank Secretary Chu and President Obama for their support and confidence in recommending and nominating me. I also thank the Committee for considering my nomination. I would like to introduce my husband of 24 years, Dr. John Hall, and his parents Mr. and Mrs. Harvey Hall, who are with me here today. In 1961, when my parents fled Cuba's Communist regime and went into exile with a three- year-old daughter and nothing but their dreams for a better life and their love for freedom, it would have been impossible to believe that their daughter would ever be nominated by the
DOE Encourages Utility Sector Nominations to the Federal Communications
the Federal the Federal Communications Commission's Communications, Security, Reliability, and Interoperability Council DOE Encourages Utility Sector Nominations to the Federal Communications Commission's Communications, Security, Reliability, and Interoperability Council March 29, 2011 - 5:22pm Addthis Because of the role communications technologies will play in the evolution toward a smarter national grid, DOE recommended in its October 2010 report, The Communications Requirements of Smart Grid Technologies, that members of the utility sector become more engaged in the federal advisory committees that consider key policy issues related to the Smart Grid, including the reliability of communications networks. Last week, the Federal Communications Commission announced that it is seeking nominations
Analysis of Voltage Notching Concerns at a Petroleum Pumping Station
This report presents the results of a voltage notching investigation at a petroleum pumping station. The analysis in this paper focuses on a particular example system where the voltage notching caused significant oscillations at the distribution system level, resulting in equipment problems at another customer supplied from the same system.
High voltage pulse conditioning
Apparatus for conditioning high voltage pulses from particle accelerators in order to shorten the rise times of the pulses. Flashover switches in the cathode stalk of the transmission line hold off conduction for a determinable period of time, reflecting the early portion of the pulses. Diodes upstream of the switches divert energy into the magnetic and electrostatic storage of the capacitance and inductance inherent to the transmission line until the switches close.
Stringfield, R.M.; Wheat, R.M. Jr.
Springfield, Ray M. (Sante Fe, NM); Wheat, Jr., Robert M. (Los Alamos, NM)
A generator for producing relatively large currents at high voltages is described. In general, the invention comprises a plurality of capacitors connected in series by a plurality of switches alternately disposed with the capacitors. The above-noted circuit is mounted for movement with respect to contact members and switch closure means so that a load device and power supply are connected across successive numbers of capacitors, while the other capacitors are successively charged with the same power supply.
Schwemin, A.J.
A generator is presented for producing relatively large currents at high voltages. In general, the invention comprises a plurality of capacitors connected in series by a plurality of switches alternately disposed with the capacitors. The circuit is mounted for movement with respect to contact members and switch closure means so that a load device and power supply are connected across successive numbers of capacitors, while the other capacitors are successively charged with the same power supply.
A Framework of Concurrent Task Scheduling and Dynamic Voltage and Frequency Scaling in Real-Time Embedded Systems with Energy Harvesting
harvesting module is comprised of a Photovoltaic (PV) panel for harvesting energy and a supercapacitor panel, state-of- charge management for the supercapacitor, and energy-harvesting- aware real-time task-leakage of the supercapacitor, and power losses in voltage converters, employs a cascaded feedback control structure
Pedram, Massoud
IEEE TRANSACTIONS ON COMPUTER-AIDED DESIGN OF INTEGRATED CIRCUITS AND SYSTEMS, VOL. , NO. , 2012 1 Dynamic Driver Supply Voltage Scaling for Organic
Dynamic Driver Supply Voltage Scaling for Organic Light Emitting Diode Displays Donghwa Shin, Student, Fellow, IEEE Abstract--Organic light emitting diode (OLED) display is a self-illuminating device]. On the other hand, an organic light emitting diode (OLED) is self-illuminating using organic light emission
High voltage variable diameter insulator
A high voltage feedthrough assembly (10) having a tubular insulator (15) extending between the ground plane ring (16) and the high voltage ring (30). The insulator (15) is made of Pyrex and decreases in diameter from the ground plane ring (16) to the high voltage ring (30), producing equipotential lines almost perpendicular to the wall (27) of the insulator (15) to optimize the voltage-holding capability of the feedthrough assembly (10).
Vanecek, David L. (Martinez, CA); Pike, Chester D. (Pinole, CA)
Automatic voltage-imbalance detector
A device is described for indicating and preventing damage to voltage cells such as galvanic cells and fuel cells connected in series by detecting sequential voltages and comparing these voltages to adjacent voltage cells. The device is implemented by using operational amplifiers and switching circuitry is provided by transistors. The device can be utilized in battery powered electric vehicles to prevent galvanic cell damage and also in series connected fuel cells to prevent fuel cell damage.
Bobbett, R.E.; McCormick, J.B.; Kerwin, W.J.
Voltage Unbalance: Power Quality Issues, Related Standards and Mitigation Techniques: Effect of Unbalanced Voltage on End Use Equipm ent Performance
Unbalanced voltages can result in adverse effects on equipment and the electric distribution system. Under unbalanced conditions the distribution system will incur more losses and heating effects, and be less stable. The effect of voltage unbalance can also be detrimental to equipment such as induction motors, power electronic converters, and adjustable speed drives (ASDs). The purpose of this study is to investigate the causes and effects of voltage unbalance as well as the related standards and mitigat...
Developments in line-voltage thermostats
A thermostat that provides reliable, accurate temperature control is the key to a comfortable, efficient space-heating system. The lack of a commercially available line-voltage thermostat that is affordable and performs well has been a significant factor in limiting the comfort and popularity of zoned residential electric heating systems. With EPRI support, two manufacturers have developed innovative, electronics-based line-voltage thermostats that offer a cost-effective control option for creating a comfortable environment with zoned electric heat. These thermostats also may help reduce energy consumption.
Kesselring, J.
Real-time static voltage scaling on multiprocessors
We propose a real-time static voltage scaling (RT-SVS) technique called T-L plane transforming, which is an extension of LLREF, an optimal real-time scheduling algorithm for multiprocessor systems. We present two RT-SVS algorithms for different types ... Keywords: energy consumption, multiprocessor systems, real-time scheduling, real-time voltage scaling
Kenji Funaoka; Shinpei Kato; Nobuyuki Yamasaki
Interline photovoltaic (I-PV) power plants for voltage unbalance compensation
This paper proposes a stationary-frame control method for voltage unbalance compensation using Interline Photovoltaic (I-PV) power system. I-PV power systems are controlled to compensate voltage unbalance autonomously. The ...
Moawwad, Ahmed
Waveform Characteristics of Voltage Sags: Definition and Algorithm Development
Voltage disturbances lasting more than one cycle are normally characterized in terms of voltage magnitude and event duration. These parameters provide an easily understood means of characterizing these types of voltage disturbances. However, magnitude and duration are not the only characteristics that affect loads. Many types of loads, such as contactors, control systems, and ac/dc drives, are also affected by other factors, such as the waveshape, the point in the waveform at which the disturbance begins...
3, 2009 3, 2009 Good afternoon, Mr. Chairman, Senator Murkowski, members of the Committee. It is a great honor to appear before you today as President Obama's nominee to be the Assistant Secretary for Environmental Management at the United States Department of Energy. I thank Secretary Chu and President Obama for their support and confidence in recommending and nominating me. I also thank the Committee for considering my nomination. I would like to introduce my husband of 24 years, Dr. John Hall, and his parents Mr. and Mrs. Harvey Hall, who are with me here today. In 1961, when my parents fled Cuba's Communist regime and went into exile with a three- year-old daughter and nothing but their dreams for a better life and their love for freedom, it
Steven E. Koonin Steven E. Koonin Under Secretary for Science Designee Senate Committee on Energy and Natural Resources April 23, 2009 Chairman Bingaman, Senator Murkowski, members of the Committee, I am honored to appear before you as President Obama's nominee for Under Secretary for Science in the Department of Energy. With me this afternoon are my wife Laurie, who has been my companion and support for 39 years, and the second of our three children, Alyson, a junior at the University of Richmond. As you consider my nomination, I thought it would be useful for me to say something about myself beyond the bare biographical facts, something about my perceptions of Science in the Department of Energy, and about what I hope to accomplish if my nomination is confirmed.
Planning of distribution networks for medium voltage and low voltage.
??Determination of the placement and rating of transformers and feeders are the main objective of the basic distribution network planning. The bus voltage and the� (more)
Ziari, Iman
High voltage feedthrough bushing
A feedthrough bushing for a high voltage diode provides for using compression sealing for all sealing surfaces. A diode assembly includes a central conductor extending through the bushing and a grading ring assembly circumferentially surrounding and coaxial with the central conductor. A flexible conductive plate extends between and compressively seals against the central conductor and the grading ring assembly, wherein the flexibility of the plate allows inner and outer portions of the plate to axially translate for compression sealing against the central conductor and the grading ring assembly, respectively. The inner portion of the plate is bolted to the central conductor for affecting sealing. A compression beam is also bolted to the central conductor and engages the outer portion of the plate to urge the outer portion toward the grading ring assembly to obtain compression sealing therebetween.
Brucker, J.P.
Common Information Model Meter Outage Nominal Interoperability Test Procedure
The CIM Meter Outage Nominal Interoperability Test Procedure is one in a series of EPRI CIM Interoperability Test Procedures (ETIPs) created by EPRI whose purpose is to thoroughly document the actors, interfaces, and test steps for the interoperability testing of specific parts of the International Electrotechnical Commission (IEC) Common Information Model (CIM) standard. The Test Procedures are initially being used for EPRI demonstration tests and are intended, over time, to form the basis of a set of C...
The Constant Voltage Transformer (CVT) for Mitigating Effects of Voltage Sags on Industrial Equipment
Electric quality problems associated with power interactions between distribution and industrial process control systems can be prevented. Surveys of large users that buy power at the transmission and distribution voltages turn up relatively few complaints about the quality of their incoming power, while surveys of small users connected at secondary voltages tum up numerous complaints about the quality of their incoming power. Three major changes in the characteristics of customer loads and power distribution systems have altered the nature of the power quality equation: (I) greater sensitivity of devices and equipment to electric power variations, (2) the interconnection of sensitive loads in extensive networks and automated processes, and (3) an increase in loads that use power electronics in some type of power conversion configuration [1][2]. This paper presents applications of the constant-voltage transformer (CVT) for mitigating the effects of electric service voltage sags on industrial equipment in an oil refinery. Unlike conventional transformers, the CVT or ferro-resonant transformer allows the core to become saturated with magnetic flux, which maintains a relatively constant output voltage during input voltage variations such as undervoltages, overvoltages, and harmonic distortion.
Ferraro, R. J.; Osborne, R.; Stephens, R.
Fusing strategies for the dual-voltage fault
This thesis focuses on the 42V - 14V fault in a dual voltage system and discusses the possibility of effective fusing. A simple model for the system had been created from technical documentation. Based on the model and the ...
Shrivastava, Rupam, 1981-
An Annotated Bibliography of High-Voltage Direct-Current Transmission and Flexible AC Transmission (FACTS) Devices, 1991-1993.
References are contained for HVDC systems, converter stations and components, overhead transmission lines, cable transmission, system design and operations, simulation of high voltage direct current systems, high-voltage direct current installations, and flexible AC transmission system (FACTS).
Litzenberger, Wayne; Lava, Val
Humidity, Temperature, and Voltage (Presentation)
An update is given on the work of the PV Quality Assurance Task Force; Group 3: studying the effects of humidity, temperature, and voltage bias.
Wohlgemuth, J.
Voltage Vehicles | Open Energy Information
Sector Vehicles Product Voltage Vehicles is a nascent, full-service alternative fuel vehicle distributor specializing in the full spectrum of electric vehicles (EV) and...
An efficient CMOS rectifier with low-voltage operation for RFID tags
A high-efficiency CMOS rectifier for radio-frequency identification (RFID) applications is presented. Using an on-chip generated clock signal, a new switching scheme is proposed to enhance the power efficiency of the conventional 4 transistor (4T)-cell ... Keywords: frequency 950 MHz, efficient CMOS rectifier, low-voltage operation, RFID tags, radio-frequency identification applications, on-chip generated clock signal, power efficiency, conventional 4 transistor-cell rectifier, charge-transfer transistors, small leakage current, external gate-boosting technique, nominal standard threshold voltage, MOS transistors, CMOS technology, power conversion efficiency
P. Kamalinejad; S. Mirabbasi; V. C. M. Leung
Price of Gulf of Mexico Natural Gas LNG Imports (Nominal Dollars...
Annual Energy Outlook 2012 (EIA)
(Nominal Dollars per Thousand Cubic Feet) Price of Gulf of Mexico Natural Gas LNG Imports (Nominal Dollars per Thousand Cubic Feet) Decade Year-0 Year-1 Year-2 Year-3 Year-4...
Price of Cameron, LA Natural Gas LNG Imports from Qatar (Nominal...
Gasoline and Diesel Fuel Update (EIA)
from Qatar (Nominal Dollars per Thousand Cubic Feet) Price of Cameron, LA Natural Gas LNG Imports from Qatar (Nominal Dollars per Thousand Cubic Feet) Decade Year-0 Year-1 Year-2...
Price of Everett, MA Natural Gas LNG Imports from Egypt (Nominal...
Egypt (Nominal Dollars per Thousand Cubic Feet) Price of Everett, MA Natural Gas LNG Imports from Egypt (Nominal Dollars per Thousand Cubic Feet) Decade Year-0 Year-1 Year-2 Year-3...
Price of Cove Point, MD Natural Gas LNG Imports from Egypt (Nominal...
Egypt (Nominal Dollars per Thousand Cubic Feet) Price of Cove Point, MD Natural Gas LNG Imports from Egypt (Nominal Dollars per Thousand Cubic Feet) Decade Year-0 Year-1 Year-2...
Compile-time dynamic voltage scaling settings: opportunities and limits
With power-related concerns becoming dominant aspects of hardware and software design, significant research effort has been devoted towards system power minimization. Among run-time power-management techniques, dynamic voltage scaling (DVS) has emerged ... Keywords: analytical model, compiler, dynamic voltage scaling, low power, mixed-integer linear programming
Fen Xie; Margaret Martonosi; Sharad Malik
Proceedings: EPRI/NERC Forum on Voltage Stability
As power systems are operated at increased stress, utilities are becoming more concerned about voltage collapse and consequent severe disruptions. This meeting, cosponsored by EPRI and NERC, provided a forum for a group of international experts to exchange information on voltage stability, including its physical understanding, operational practices, and application of available tools.
Strain-optic voltage monitor
A voltage monitor which uses the shift in absorption edge of crystalline material to measure strain resulting from electric field-induced deformation of piezoelectric or electrostrictive material, providing a simple and accurate means for measuring voltage applied either by direct contact with the crystalline material or by subjecting the material to an electric field.
Weiss, J.D.
Definition: Automated Voltage And Var Control | Open Energy Information
Voltage And Var Control Voltage And Var Control Jump to: navigation, search Dictionary.png Automated Voltage And Var Control Automated voltage and VAR control requires coordinated operation of reactive power resources such as capacitor banks, voltage regulators, transformer load-tap changers, and distributed generation (DG) with sensors, controls, and communications systems. These devices could operate autonomously in response to local events or in response to signals from a central control system.[1] View on Wikipedia Wikipedia Definition Also Known As Volt-VAR Control (VVC) Related Terms smart grid, Reactive Power References ↑ SmartGrid.gov 'Description of Functions' An i LikeLike UnlikeLike You like this.Sign Up to see what your friends like. nline Glossary Definition Retrieved from
Nomination & Selection Guidelines | U.S. DOE Office of Science (SC)
Office of Science (SC) Website
Nomination & Selection Guidelines Nomination & Selection Guidelines The Ernest Orlando Lawrence Award Lawrence Award Home Nomination & Selection Guidelines Award Laureates Ceremony The Life of Ernest Orlando Lawrence Contact Information The Ernest Orlando Lawrence Award U.S. Department of Energy SC-2/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-9395 E: email@example.com Nomination & Selection Guidelines Print Text Size: A A A RSS Feeds FeedbackShare Page Jump to: Nomination Guidelines | Lawrence Award Category Descriptions | Lawrence Award Assessment Criteria, Merit Review, and Selection | Preparation of Nomination Materials | Additional Information The 2013 Ernest Orlando Lawrence Award Nomination Guidelines The Ernest Orlando Lawrence Award is bestowed by the Secretary of the U.S.
A Hybrid Framework for Voltage Security Assessment Integrating Simulation and Measurement Based Approaches
Voltage stability is the ability of a power system to maintain adequate voltage magnitudes at buses, which is a major concern in daily power system operations and a leading factor to limit power transfers in a prevailing open-access environment. Currently, simulation-based voltage security assessment (VSA) tools are applied widely by electric utilities to analyze either steady-state or transient voltage stability issues. Those VSA tools can help operators foresee the next critical ...
Two terminal line voltage thermostat
A two terminal line voltage thermostat includes a switch which effectively connects line voltage to a heater load. The entire process is controlled by an integrated circuit microcontroller which is powered by a rectified voltage from a transformer secondary connected to a primary which is in series with the heater load. Backup battery power is provided to maintain limited functions of the microcontroller in the event of overall power loss. The microcontroller is programmed to meet the temperature sensing and control requirements specific to a two terminal electric baseboard heating installation. 7 figs.
Stalsberg, K.J.; Ingalls, J.E.; Hoglund, S.R.
Battery Specifications Manufacturer: Sanyo Type: Nickel-Metal Hydride Number of Modules: 204 Nominal Module Voltage: 1.35 V Nominal System Voltage: 275 V Nominal Pack Capacity: 5.5...
Fault Detection and Isolation in Low-Voltage DC Distribution ...
A University of Colorado research team led by Jae-Do Park has developed a fault detection and isolation scheme for a low-voltage DC-bus microgrid system, ...
Low-Voltage Cable Aging Management Guidance
This report, intended for use by power plant engineers and craft and administrative personnel who are responsible for cable system aging management, provides guidance on the effective and efficient application of current information and techniques related to aging and condition monitoring (CM) of low-voltage cables. The identification of cables that are prone to early aging and the timely replacement or repair of cables that are degraded will minimize unnecessary power losses, unplanned shutdowns, ...
Chapter 4 - Understanding Voltage Sags
This chapter of the EPRI Solutions PQ Encyclopedia provides information for understanding the voltage sag, which is the single most potent cause of end user power quality (PQ) problems.
Living and Working Safely Around High-Voltage Power Lines.
High-voltage transmission lines can be just as safe as the electrical wiring in the homes--or just as dangerous. The crucial factor is ourselves: they must learn to behave safely around them. This booklet is a basic safety guide for those who live and work around power lines. It deals primarily with nuisance shocks due to induced voltages, and with potential electric shock hazards from contact with high-voltage lines. References on possible long-term biological effects of transmission lines are shown. In preparing this booklet, the Bonneville Power Administration has drawn on more than 50 years of experience with high-voltage transmission. BPA operates one of the world`s largest networks of long-distance, high-voltage lines. This system has more than 400 substations and about 15,000 miles of transmission lines, almost 4,400 miles of which are operated at 500,000 volts.
United States. Bonneville Power Administration.
Definition: Automated Voltage Regulators | Open Energy Information
Regulators Regulators Jump to: navigation, search Dictionary.png Automated Voltage Regulators Voltage regulators are transformers that can increase or decrease the voltage on a distribution circuit to help keep the voltage within a pre-determined band. Unlike capacitor banks, voltage regulators cannot adjust power factor. These devices typically monitor the voltage at the location where they are connected, and compare it to a programmed set point. If the voltage deviates too far from the set point, the voltage regulator can increase or decrease its output voltage by moving the tap on the secondary side up or down. An automated voltage regulator can operate with remote control signals, or in concert with other area voltage control devices, to help regulate distribution voltage in a coordinated fashion.
High-voltage-compatible, fully depleted CCDs
result of this high-voltage requirement, we have taken a di?voltage is necessary in order to meet the PSF requirementsrequirements for SNAP have resulted in a need to operate at substrate bias voltages
DECENTRALIZED CONTROL ARCHITECTURE FOR COUPLING MICROGRIDS INTO DISTRIBUTION NETWORKS 1 Task 1: Coupling Low-Voltage Microgrids into
DECENTRALIZED CONTROL ARCHITECTURE FOR COUPLING MICROGRIDS INTO DISTRIBUTION NETWORKS 1 Task 1: Coupling Low-Voltage Microgrids into Mid-Voltage Distribution Systems Zhao Wang, Student Member, IEEE-voltage (LV) microgrids. At the same time, reactive power is dispatched coordinatively so that voltage
Lemmon, Michael
Assessment of research directions for high voltage direct current power systems. Quarterly technical progress report, October 1, 1980-December 31, 1980
Activities during this quarterly period on proposed HVDC systems research are reported. These activities include studies of HVDC converters, computerized simulation of HVDC systems, circuit breakers, and long-range planning of HVDC projects. (LCL)
Daniel B. Poneman Daniel B. Poneman Before the Committee on Energy and Natural Resources United States Senate May 5, 2009 Chairman Bingaman, Ranking Member Murkowski, and distinguished Members of the Committee, it is an honor and a privilege to appear before you today as President Obama's nominee to be Deputy Secretary of Energy. I would like to introduce my wife of nearly 25 years, Susan, and our sons, Michael and William. Our daughter, Claire, is away at college. I am grateful and humbled by the confidence that President Obama and Secretary Chu have expressed in me through this nomination. President Obama has articulated a clear and compelling vision of America's energy future - one that will transform our economy, protect our security, and save our planet from the worst impacts of climate change.
A CMOS threshold voltage reference source for very-low-voltage applications
This paper describes a CMOS voltage reference that makes use of weak inversion CMOS transistors and linear resistors, without the need for bipolar transistors. Its operation is analogous to the bandgap reference voltage, but the reference voltage is ... Keywords: Threshold voltage, Ultra-low-power, Very-low-voltage, Voltage reference
Luis H. C. Ferreira; Tales C. Pimenta; Robson L. Moreno
High-voltage air-core pulse transformers
General types of air core pulse transformers designed for high voltage pulse generation and energy transfer applications are discussed with special emphasis on pulse charging systems which operate up to the multi-megavolt range. The design, operation, dielectric materials, and performance are described. It is concluded that high voltage air core pulse transformers are best suited to applications outside the normal ranges of conventional magnetic core transformers. In general these include charge transfer at high power levels and fast pulse generation with comparatively low energy. When properly designed and constructed, they are capable of delivering high energy transfer efficiency and have demonstrated superior high voltage endurance. The principal disadvantage of high voltage air core transformers is that they are not generally available from commercial sources. Consequently, the potential user must become thoroughly familiar with all aspects of design, fabrication and system application before he can produce a high performance transformer system. (LCL)
Rohwein, G. J.
Connectivity and Bidirectional Energy Transfer in DC Microgrid Featuring Different Voltage Characteristics
In this paper, the connectivity issues related to linking two DC buses featuring different voltage characteristics, in terms of voltage level and ripple, in a DC micro grid are identified, analyzed and discussed. A controlled DC-DC converter was used ... Keywords: Bidirectional energy transfer, buck-boost converter, DC distribution systems, DC microgrids, voltage ripple
Mustafa Farhadi, Ahmed Mohamed, Osama Mohammed
A high-voltage low-power DC-DC buck regulator for automotive applications
This work presents a High-Voltage Low-Power CMOS DC-DC buck regulator for automotive applications. The overall system, including the high and low voltage analog devices, the power MOS and the low voltage digital devices, was realized in the Austriamicrosystems ... Keywords: DC-DC regulator, buck converter, current control, low quiscent current, pulse frequency modulation
G. Pasetti; L. Fanucci; R. Serventi
Nomination & Selection Guidelines Nomination & Selection Guidelines The Enrico Fermi Award Fermi Award Home Nomination & Selection Guidelines Award Laureates Ceremony The Life of Enrico Fermi Contact Information The Enrico Fermi Award U.S. Department of Energy SC-2/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-9395 E: firstname.lastname@example.com Nomination & Selection Guidelines Print Text Size: A A A RSS Feeds FeedbackShare Page Jump to: Fermi Award Assessment Criteria, Merit Review, and Selection | Preparation of Nomination Materials The 2013 Enrico Fermi Award Nomination Guidelines The Enrico Fermi Award is bestowed by the President of the United States to an individual or individuals of international stature in recognition of exceptional scientific, technical, engineering, and/or management
Sacramento Area Voltage Support Environmental Impact Statement
E E R R A N E V A D A R E G I O N Sacramento Area Voltage Support DRAFT ENVIRONMENTAL IMPACT STATEMENT DRAFT ENVIRONMENTAL IMPACT STATEMENT DOE/EIS-0323 NOVEMBER 2002 COVER SHEET Title: Sacramento Area Voltage Support Draft Environmental Impact Statement (EIS) Lead Agency: Western Area Power Administration (Western) Location: Alameda, Contra Costa, Placer, Sacramento, San Joaquin, and Sutter Counties, State of California. EIS Number: DOE/EIS-0323 Contact: Ms. Loreen McMahon, Environmental Project Manager Western Area Power Administration Sierra Nevada Region 114 Parkshore Drive Folsom, CA 95630 (916) 353-4460 (916) 985-1936 fax email: email@example.com Website: Information is also available on our website: www.wapa.gov Hotline: 1-877-913-4440 (toll-free) Abstract The Western Area Power Administration's Central Valley Project transmission system forms an integral part of
Design and Test of DC Voltage Link Conversion System and Brushless Doubly-Fed Induction Generator for Variable-Speed Wind Energy Applications: August 1999--May 2003
This report describes four low-cost alternative power converters for processing the power developed by a doubly fed wound-rotor induction generator for wind energy conversion systems.
Lipo, T.A.; Panda, D.; Zarko, D.
A voltage controlled current source
A seven decade, voltage controlled current source is described for use in testing intermediate range nuclear instruments that covers the entire test current range of from 10 picoampers to 100 microamperes. High accuracy is obtained throughout the entire seven decades of output current with circuitry that includes a coordinated switching scheme responsive to the input signal from a hybrid computer to control the input voltage to an antilog amplifier, and to selectively connect a resistance to the antilog amplifier output to provide a continuous output current source as a function of a preset range of input voltage. An operator controlled switch provides current adjustment for operation in either a real-time simulation test mode or a time response test mode.
Casne, G.M.
Fiber-optic voltage sensor
A fiber optic voltage sensor is described which includes a source of light, a reference fiber for receiving a known percentage of the light and an electrostrictive element having terminals across which is applied, a voltage to be measured. The electrostrictive element is responsive to the applied voltage to assume an altered physical state. A measuring fiber also receives a known percentage of light from the light source and is secured about the electrostrictive element. The measuring fiber is provided with a cladding and exhibits an evanescent wave in the cladding. The measuring fiber has a known length which is altered when the electrostrictive element assumes its altered physical state. A differential sensor is provided which senses the intensity of light in both the reference fiber and the measuring fiber and provides an output indicative of the difference between the intensities.
Wood, C.B.
Voltage Node Arcing in the ICRH Antenna Vacuum Transmission Lines at JET
The observation of parasitic low-VSWR activity during operations of JET RF plant and the damage caused by arcing at the voltage-node in the vacuum transmission line (VTL) in 2004 highlight the importance of the problem of low-voltage breakdown in the ICRH systems. Simulations demonstrate little response of the RF circuit to the voltage-node arcing which explains why it remains largely unnoticed and complicates the design of protection systems. Analysis of the damage pattern produced by the voltage-node arcing suggests that multipactor-related phenomena occurring at elevated voltage thresholds in conditions of unfavorable VTL geometry are most plausible arc-provoking factors.
Monakhov, I.; Graham, M.; Mayoral, M.-L.; Nicholls, K.; Walden, A. [Euratom/UKAEA Fusion Association, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Bobkov, V. [Max-Planck Institut fuer Plasmaphysik, EURATOM Association, D-85748 Garching (Germany)
Planar LTCC transformers for high voltage flyback converters: Part II.
This paper is a continuation of the work presented in SAND2007-2591 'Planar LTCC Transformers for High Voltage Flyback Converters'. The designs in that SAND report were all based on a ferrite tape/dielectric paste system originally developed by NASCENTechnoloy, Inc, who collaborated in the design and manufacturing of the planar LTCC flyback converters. The output/volume requirements were targeted to DoD application for hard target/mini fuzing at around 1500 V for reasonable primary peak currents. High voltages could be obtained but with considerable higher current. Work had begun on higher voltage systems and is where this report begins. Limits in material properties and processing capabilities show that the state-of-the-art has limited our practical output voltage from such a small part volume. In other words, the technology is currently limited within the allowable funding and interest.
Schofield, Daryl (NASCENTechnology, Inc., Watertown, SD); Schare, Joshua M., Ph.D.; Slama, George (NASCENTechnology, Inc., Watertown, SD); Abel, David (NASCENTechnology, Inc., Watertown, SD)
Multilevel cascade voltage source inverter with seperate DC sources
A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations.
Peng, Fang Zheng (Knoxville, TN); Lai, Jih-Sheng (Blacksburg, VA)
Multilevel cascade voltage source inverter with separate DC sources
A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations. 15 figs.
Portec Voltage Regulators: for Emergency Diesel Generators
This report contains information to help utilities address emergency diesel generator voltage regulator issues.
Engine system electronics for high-temperature and high-voltage electronics, materials, and components for under-hood applications. Project accomplishment summary
The purpose of the project was to develop the technology needed to build the next family of automotive ignition systems while improving the performance and reliability of the ignition systems presently in use. This was accomplished by learning from the industrial partner where the state of the art stood and understanding the problems that needed to be solved before fundamental advancements could be made. Then, resources from the DOE facilities were matched to the challenges presented by the industrial partner. The role of the industrial partner was to describe the state of the art concerning the manufacturing and performance of automotive ignition systems to organizations at the DOE facilities. The role of DOE facilities was to apply basic research and development techniques to the problems presented by the industrial partner while advancing the capabilities available to DOE Defense Programs.
Sohns, C.W. [Lockheed Martin Energy Systems, Inc., Oak Ridge, TN (United States); Van Uum, D. [General Motors Corp., Flint, MI (United States). Delphi Automotive Systems
Cable Aging Management Training Course for Low-Voltage Cables
The "EPRI PSE Cable Aging Training Course for Low-Voltage Cables" provides a basis for understanding of the aging of the insulation and jackets of electrical cables used in low-voltage systems. Practical techniques for determining which cables are prone to premature aging and for evaluating their condition are described. The course contains 11 modules. The first 9 modules describe the body of the cable aging management process. The last two modules, "Cable Failure Assessment" and "Performing a Walkdown o...
Pinpointing the cause of an outage for something as complex and interconnected as the high voltage transmission system is a ve
Ellen P. Vancko Ellen P. Vancko email@example.com Electric System Update: Sunday August 17, 2003, 5:00 p.m. The electric transmission system is now operating reliably. All electric power transmission lines that were removed from service during the blackout on August 14, 2003, have been returned to service with one exception. The lines between Michigan and Ontario remain out of service due to operational security reasons; however, they are expected to be returned to service later this evening. Most of the electric generating units that were removed from service during the blackout have now been returned to service (the exact number of units that went out of service is not yet known). Twenty-one of these remain out of service. A number of these generating units are expected to return to service either
Turbine-Generator Topics for Power Plant Engineers: Synchronous Generator Voltage Regulator Basics
This material is intended for the new engineer, the control room operator, management, or the non-engineer. The basics of a synchronous generator excitation system; the fundamentals of the voltage regulator; and its controls and functions are discussed. The typical exciter types are covered, but not in detail. There is also basic information on voltage regulator maintenance issues. Put simply, the excitation system is made up of three basic component systems. The voltage regulator monitors the synchronou...
E. O. Lawrence Award Nominations | U.S. DOE Office of Science (SC)
E. O. E. O. Lawrence Award Nominations News Featured Articles Science Headlines 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 Presentations & Testimony News Archives Contact Information Office of Science U.S. Department of Energy 1000 Independence Ave., SW Washington, DC 20585 P: (202) 586-5430 12.04.12 E. O. Lawrence Award Nominations The Office of Science is now accepting nominations for the 2013 E. O. Lawrence Award. Print Text Size: A A A Subscribe FeedbackShare Page Call for Nominations - 2013 E. O. Lawrence Award Nominations are sought for the 2013 E. O. Lawrence Awards beginning now through May 31, 2013. The outcome of the 2012 Lawrence Awards is anticipated to be announced soon. The Ernest Orlando Lawrence Award is bestowed by the Secretary of the U.S. Department of Energy to mid-career scientists and engineers in recognition
Enrico Fermi Award Nominations | U.S. DOE Office of Science (SC)
Enrico Fermi Enrico Fermi Award Nominations News Featured Articles Science Headlines 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 Presentations & Testimony News Archives Contact Information Office of Science U.S. Department of Energy 1000 Independence Ave., SW Washington, DC 20585 P: (202) 586-5430 12.04.12 Enrico Fermi Award Nominations The Office of Science is now accepting nominations for the 2013 Enrico Fermi Award. Print Text Size: A A A Subscribe FeedbackShare Page Call for Nominations - 2013 Enrico Fermi Award Nominations are sought for the 2013 Enrico Fermi Award beginning now through May 31, 2013. The outcome of the 2012 Fermi Award is anticipated to be announced soon. The Enrico Fermi Award is a Presidential award and one of the longest running and most prestigious science and technology awards given by the
Statement from Energy Secretary Samuel W. Bodman on the Nomination of
the Nomination the Nomination of Thomas P. D'Agostino as Under Secretary for Nuclear Security and Administrator of NNSA Statement from Energy Secretary Samuel W. Bodman on the Nomination of Thomas P. D'Agostino as Under Secretary for Nuclear Security and Administrator of NNSA May 17, 2007 - 12:55pm Addthis "Today the President announced his intention to nominate Thomas P. D'Agostino as Under Secretary for Nuclear Security and Administrator of the National Nuclear Security Administration (NNSA). Tom served as NNSA's Acting Administrator for three months and as Deputy Administrator for Defense Programs for the past fourteen months. In these roles, Tom has done an outstanding job and has earned my full confidence. With this nomination, we are making NNSA even stronger and I am eager to
A Review Of Water Contents Of Nominally Anhydrous Natural Minerals In The
A Review Of Water Contents Of Nominally Anhydrous Natural Minerals In The A Review Of Water Contents Of Nominally Anhydrous Natural Minerals In The Mantles Of Earth, Mars And The Moon Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Review Of Water Contents Of Nominally Anhydrous Natural Minerals In The Mantles Of Earth, Mars And The Moon Details Activities (0) Areas (0) Regions (0) Abstract: Olivine, pyroxene and garnet are nominally anhydrous but can accommodate tens to hundreds of parts per million (ppm) H2O or "water" in the form of protons incorporated in defects in their mineral structure. This review concerns the amount of water in nominally anhydrous minerals from mantle and mantle-derived rocks: peridotites, eclogites, megacrysts, basalts and kimberlites. Trends between internal and external parameters
Time varying voltage combustion control and diagnostics sensor
A time-varying voltage is applied to an electrode, or a pair of electrodes, of a sensor installed in a fuel nozzle disposed adjacent the combustion zone of a continuous combustion system, such as of the gas turbine engine type. The time-varying voltage induces a time-varying current in the flame which is measured and used to determine flame capacitance using AC electrical circuit analysis. Flame capacitance is used to accurately determine the position of the flame from the sensor and the fuel/air ratio. The fuel and/or air flow rate (s) is/are then adjusted to provide reduced flame instability problems such as flashback, combustion dynamics and lean blowout, as well as reduced emissions. The time-varying voltage may be an alternating voltage and the time-varying current may be an alternating current.
Chorpening, Benjamin T. (Morgantown, WV); Thornton, Jimmy D. (Morgantown, WV); Huckaby, E. David (Morgantown, WV); Fincham, William (Fairmont, WV)
High voltage, direct current power supplies are described for use with battery powered nuclear detection equipment. The particular advantages of the power supply described, are increased efficiency and reduced size and welght brought about by the use of transistors in the circuit. An important feature resides tn the employment of a pair of transistors in an alternatefiring oscillator circuit having a coupling transformer and other circuit components which are used for interconnecting the various electrodes of the transistors.
Driver, G.E.
Proceedings: EPRI/NERC forum on voltage stability
Over the past two decades, the interconnected electric systems serving North America have been increasingly subjected to reductions in generation and transmission capacity reserves, increasing complexity of load character, and the need for power transfer over longer distances. As a result, voltage stability limitations are becoming an important factor for utility personnel to consider when designing and operating an electric system. To address this situation, EPRI and NERC cosponsored a forum to exchange information between the various sectors of the utility industry on voltage control technology. The forum covered available tools and practices; utility operating practices, procedures, and experiences; planning and operating studies; and energy management system (EMS) vendor viewpoints. Participants agreed that a continuing coordinated effort involving all industry groups was needed in the voltage stability area. Attendees also identified specific subject areas of importance to help direct future studies. Individual papers are indexed separately.
Maratukulam, D. (ed.) (Kennedy (Thomas), Florissant, MO (United States))
Case study of a central-station grid-intertie photovoltaic system with V-trough concentration
This presentation is a cast study of an installed, central-station (no storage), utility-intertie photovoltaic (PV) system in Sede Boqer, Israel (latitude 30.9{degree}N). The nominally 12 kW peak PV system is comprised of 189 polycrystalline silicon modules mounted on inexpensive, one-axis north-south horizontal trackers with V-trough mirrors for optical boost. The power conditioning unit operates at a fixed voltage rather than at maximum power point (MPP). The primary task in analyzing the installed system was to investigate the cause of measured power output significantly below the design predictions of the installers, and to recommend system design modifications. Subsequent tasks included the quantitative assessment of fixed-voltage operation and of the energetic value of V-trough concentration and one-axis tracking for this system. Sample results show: (1) fixed-voltage operation at the best fixed voltage (BFV) can achieve around 96% of the yearly energy of MPP operation; (2) the sensitivity of the yearly energy delivery to the selection of fixed voltage and its marked asymmetry about the BFV; (3) the influences of inverter current constraints on yearly energy delivery and BFV; and (4) how the separate effects of tracking and optical concentration increase yearly energy delivery.
Freilich, J.; Gordon, J.M. (Ben-Gurion Univ. of the Negev, Sede Boqer (Israel))
Interaction of Multiple Distributed Energy Resources in Voltage Regulation
Distributed energy resources (DE) with power electronics (PE) interfaces with the right control are capable of providing reactive power related ancillary services; voltage regulation in particular has drawn much attention. In this paper the problem of how to coordinate control multiple DEs to regulate the local voltage in the distribution system is addressed. A control method for voltage regulation using the DE PE controller is presented and based on the proposed control scheme; the voltage regulation of a distribution system with one DE and two DEs are tested, respectively. The factors affecting the gain parameters of the PE controller are investigated. The simulation results show that the parameters of the controller determine its dynamic response for voltage regulation and the factors associated with the network characteristics, such as locations of DEs and the amount of load, affect the impact range of the controller. The research work presented in this paper can be potentially used for the control system design of Smart Grid or Utility of the Future.
Li, Huijuan [University of Tennessee, Knoxville (UTK); Li, Fangxing [ORNL; Xu, Yan [ORNL; Rizy, D Tom [ORNL; Kueck, John D [ORNL
Voltage unbalance effects on induction motor performance
The reliability of electric drives and driven motors depends on the quality of the power supply voltage especially in the critical industrial process. In this work, a theoretical study of the effects of voltage unbalances, sags and swells on induction ... Keywords: efficiency, power losses and derating factor, sags, symmetrical components, voltage unbalance
L. Refoufi; H. Bentarzi; F. Z. Dekhandji
Effects of Distributed Energy Resources on Conservation Voltage Reduction (CVR)
Conservation Voltage Reduction (CVR) is one of the cheapest technologies which can be intelligently leveraged to provide considerable energy savings. The addition of renewables in the form of distributed resources can affect the entire power system, but more importantly, affects the traditional substation control schemes at the distribution level. This paper looks at the effect on energy consumption, peak load reduction, and voltage profile changes due to the addition of distributed generation in a distribution feeder using combinations of volt var control. An IEEE 13-node system is used to simulate the various cases. Energy savings and peak load reduction for different simulation scenarios are compared.
Singh, Ruchi; Tuffner, Francis K.; Fuller, Jason C.; Schneider, Kevin P.
Voltage Control Devices on the IEEE 8500 Node Test Feeder
The IEEE Test Cases provide researchers with distribution system models that can be used to validate new analytic methods. The newest of these models is the 8500-node test feeder which contains multiple devices for voltage control. In addition to a substation regulator there are multiple inline regulators as well as capacitor banks. This paper will discuss the detail in which voltage control devises should be modeled when examining large distribution systems. This discussion will include issues associated with power flow analysis for a single time step as well as for time series analysis.
Schneider, Kevin P.; Fuller, Jason C.
High voltage RF feedthrough bushing
Described is a multi-element, high voltage radio frequency bushing for trmitting RF energy to an antenna located in a vacuum container. The bushing includes a center conductor of complex geometrical shape, an outer coaxial shield conductor, and a thin-walled hollow truncated cone insulator disposed between central and outer conductors. The shape of the center conductor, which includes a reverse curvature portion formed of a radially inwardly directed shoulder and a convex portion, controls the uniformity of the axial surface gradient on the insulator cone. The outer shield has a first substantially cylindrical portion and a second radially inwardly extending truncated cone portion.
Grotz, Glenn F. (Huntington Station, NY)
Influence of voltage drop to electric drive with induction motor and voltage sourced inverter
This paper solves problematic of immunity from the voltage drop of the power supply of the electric drive with induction motor with Voltage-Fed inverter. There are reflected opportune control algorithms for the quickly to change of working regime from ... Keywords: electric drive with induction motor, electric drive with voltage sourced inverter, voltage drop
P. Bene�; J. Fo?t; M. Pittermann
U.S. Nominal Cost per Natural Gas Well Drilled (Thousand Dollars...
Natural Gas Well Drilled (Thousand Dollars per Well) U.S. Nominal Cost per Natural Gas Well Drilled (Thousand Dollars per Well) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5...
U.S. Nominal Cost per Foot of Natural Gas Wells Drilled (Dollars...
Natural Gas Wells Drilled (Dollars per Foot) U.S. Nominal Cost per Foot of Natural Gas Wells Drilled (Dollars per Foot) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5 Year-6...
U.S. Nominal Cost per Crude Oil Well Drilled (Thousand Dollars...
Oil Well Drilled (Thousand Dollars per Well) U.S. Nominal Cost per Crude Oil Well Drilled (Thousand Dollars per Well) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5 Year-6 Year-7...
U.S. Nominal Cost per Crude Oil, Natural Gas, and Dry Well Drilled...
Oil, Natural Gas, and Dry Well Drilled (Thousand Dollars per Well) U.S. Nominal Cost per Crude Oil, Natural Gas, and Dry Well Drilled (Thousand Dollars per Well) Decade Year-0...
U.S. Nominal Cost per Foot of Crude Oil Wells Drilled (Dollars...
Oil Wells Drilled (Dollars per Foot) U.S. Nominal Cost per Foot of Crude Oil Wells Drilled (Dollars per Foot) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5 Year-6 Year-7 Year-8...
U.S. Nominal Cost per Dry Well Drilled (Thousand Dollars per...
Dry Well Drilled (Thousand Dollars per Well) U.S. Nominal Cost per Dry Well Drilled (Thousand Dollars per Well) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5 Year-6 Year-7...
U.S. Nominal Cost per Foot of Crude Oil, Natural Gas, and Dry...
Oil, Natural Gas, and Dry Wells Drilled (Dollars per Foot) U.S. Nominal Cost per Foot of Crude Oil, Natural Gas, and Dry Wells Drilled (Dollars per Foot) Decade Year-0 Year-1...
Low voltage operation of plasma focus
Plasma foci of compact sizes and operating with low energies (from tens of joules to few hundred joules) have found application in recent years and have attracted plasma-physics scientists and engineers for research in this direction. We are presenting a low energy and miniature plasma focus which operates from a capacitor bank of 8.4 {mu}F capacity, charged at 4.2-4.3 kV and delivering approximately 52 kA peak current at approximately 60 nH calculated circuit inductance. The total circuit inductance includes the plasma focus inductance. The reported plasma focus operates at the lowest voltage among all reported plasma foci so far. Moreover the cost of capacitor bank used for plasma focus is nearly 20 U.S. dollars making it very cheap. At low voltage operation of plasma focus, the initial breakdown mechanism becomes important for operation of plasma focus. The quartz glass tube is used as insulator and breakdown initiation is done on its surface. The total energy of the plasma focus is approximately 75 J. The plasma focus system is made compact and the switching of capacitor bank energy is done by manual operating switch. The focus is operated with hydrogen and deuterium filled at 1-2 mbar.
Shukla, Rohit; Sharma, S. K.; Banerjee, P.; Das, R.; Deb, P.; Prabahar, T.; Das, B. K.; Adhikary, B.; Shyam, A. [Energetics and Electromagnetics Division, Facility for Electromagnetic Systems, Bhabha Atomic Research Center, Visakhapatanam, A.P. 530012 (India)
Simulation for Performance Analysis of Grid-Connected Induction Generators with Input Voltage Control
With the increasing application of wind energy, various technologies are developed for analyzing the performance of grid-connected induction generator (GIG) based wind energy conversion systems (WECSs). Input voltage control is one among them. In the ... Keywords: grid-connected induction generators (GIGs), wind energy conversion systems (WECSs), input voltage control, performance analysis, MATLAB
Farhad Ilahi Bakhsh, Shirazul Islam, Sayeed Ahmad
University Academic Advising Awards Nomination Process Please follow the steps below in order to access and submit a nomination for the university advising awards.
" represents the search term(s) you entered. However, you will see the site you just joined if you click the My. If you'd like to join any of them, click . E. To search for a particular site or group of sites: 1. Enter your search terms in the Search box. In order to submit your advising nomination form you must find
Virginia Tech
DSP Based Ultracapacitor System for Hybrid-Electric Vehicles Juan W. Dixon
sources like fuel-cells, microturbines, zinc-air batteries or other supply unable to recover energy from bank are: nominal voltage: 300 Vdc; nominal current: 200 Adc; capacitance: 20 Farads. The amount of energy stored allows delivering 40 kW of power during 20 seconds, which is enough to accelerate
Rudnick, Hugh
Assessment and Evaluation of Next Generation High-Voltage DC Technologies�Phase 2
As an established technology for bulk power transmission, high-voltage direct current (HVDC) power transmission is being used worldwide, and more than 100 schemes are operating at present. Advances in voltage sourced converter (VSC) technologies and power electronic devices with use of insulated-gate bipolar transistors (IGBTs) will provide improved system performance and reliability. Also, the present highest operating voltage is +/- 800 kV as China and India are building +/- 800-kV lines. Anticipating ...
Power and Voltage Smooth Control of Doubly Fed Induction Generator
Doubly-fed induction generator (DFIG) is the leading in wind power technology currently. In this paper, decoupling control of DFIG is studied and a new energy storage device is used in the smooth control of DFIG system's power and voltage. This new method ... Keywords: Doubly fed induction generator, Energy storage device, Decoupling control
An-Ren Ma, Cai-Xia Wang, Zhi-Wen Zhou, Tao Wu
Wire-Extrusion Process Disrupted By Voltage Sags
This PQTN Case Study investigates voltage sags originating from a utility distribution system at a wire-extrusion plant near Cleveland, Ohio that were causing a wire-drawing process to malfunction, resulting in broken tungsten wire and hours of time spent restarting the manufacturing process.
High voltage gas insulated transmission line with continuous particle trapping
This invention provides a novel high voltage gas insulated transmission line utilizing insulating supports spaced at intervals with snap-in means for supporting a continuous trapping apparatus and said trapping apparatus having perforations and cutouts to facilitate trapping of contaminating particles and system flexibility.
Cookson, Alan H. (Pittsburgh, PA); Dale, Steinar J. (Monroeville, PA)
C17: Voltage Impulse Induced Bistable Magnetization Switching and ...
Non-violate dynamic magnetization switch was also realized by voltage impulse ... Concentric Nanoparticles Embedded in Low Temperature Synthesized TiO2 Films .... F2: Development of the On-Line Mechanical Property Prediction System for ... Sintered Nd-Fe-B Magnets by Transmission Electron Microscopy Analysis.
Control Techniques to Eliminate Voltage Emergencies in High Performance Processors
negligible impact on perfor mance and energy. With the ITRS roadmap predicting aggres sive drops in supply. At present it is difficult to design a high quality, low impedance power supply system, and industry trends in current variability, often re ferred to as the dI/dt problem, can cause supply voltage fluc tuations
Martonosi, Margaret
negligible impact on perfor- mance and energy. With the ITRS roadmap predicting aggres- sive drops in supply. At present it is difficult to design a high quality, low impedance power supply system, and industry trends in current variability, often re- ferred to as the dI/dt problem, can cause supply voltage fluc- tuations
Gupta, Rajiv
Rank based dynamic voltage and frequency scaling fortiled graphics processors
With increasing interest in sophisticated graphics capabilities in mobile systems, energy consumption of graphics hardware is becoming a major design concern in addition to the traditional performance enhancement criteria. Our study of various modern ... Keywords: dynamic voltage and frequency scaling, graphics processor, low power, workload prediction
B.V.N Silpa; Gummidipudi Krishnaiah; Preeti Ranjan Panda
Distributed Generation Study/Patterson Farms CHP System Using Renewable
Farms CHP System Using Renewable Farms CHP System Using Renewable Biogas < Distributed Generation Study Jump to: navigation, search Study Location Auburn, New York Site Description Agricultural Study Type Field Test Technology Internal Combustion Engine Prime Mover Caterpillar G379 Heat Recovery Systems Built-in Fuel Biogas System Installer Martin Machinery System Enclosure Dedicated Shelter System Application Combined Heat and Power Number of Prime Movers 1 Stand-alone Capability None Power Rating 200 kW0.2 MW 200,000 W 200,000,000 mW 2.0e-4 GW 2.0e-7 TW Nominal Voltage (V) 480 Heat Recovery Rating (BTU/hr) 1366072 Cooling Capacity (Refrig/Tons) Origin of Controller 3rd Party Custom Made Component Integration Customer Assembled Start Date 2007/05/02 Monitoring Termination Date 2007/05/26
Dynamic Voltage Scaling on a Low-Power Microprocessor
Power consumption is the limiting factor for the functionality of future wearable devices. Since interactive applications like wireless information access generate bursts of activities, it is important to match the performance of the wearable device accordingly. This paper describes a system with a microprocessor whose speed can be varied (frequency scaling) as well as its input voltage. Voltage scaling is important for reducing power consumption to very low values when operating at low speeds. Measurements show that the energy per instruction at minimal speed (59 MHz) is 1/5 of the energy required at full speed (251 MHz). The frequency and voltage can be scaled dynamically from user space in only 140 � s. This allows power-aware applications to quickly adjust the performance level of the processor whenever the workload changes. 1
Johan Pouwelse; Koen Langendoen; Henk Sips
The effect of DVR location for enhancing voltage sag
Recently, Dynamic Voltage Restorer (DVR) has become a popular power electronic device as a protection for sensitive loads from voltage sag. Voltage sag widely known as one of the major problem in power quality, it is defined as a short reduction of voltage ... Keywords: dynamic voltage restorer, power quality, voltage sag
Rohanim Ibrahim; Ahmed M. A. Haidar; M. Zahim; Herbert Iu
Measurement-based Voltage Stability Margin Calculator (MVSMC) v1.0
Voltage stability is a major concern in daily power system operations and a leading factor to limit power transfers in a prevailing open access environment. Voltage instability usually starts from a local bus or area, and then may evolve into a wide-area instability problem if it cannot be controlled locally. This program utilizes EPRImeasurement-based voltage stability monitoring technology and is able to calculate voltage stability margin indices at a load bus or for an entire load area using the measu...
Emergency Diesel Generator Voltage Regulator Guidelines
This product kit, containing six separate documents, provides information to help utilities address emergency diesel generator voltage regulator issues and maintenance.
Enhancing Open Circuit Voltage by Combining Thermoelectric ...
Enhancing Open Circuit Voltage by Combining Thermoelectric Materials and Dye -Sensitized Solar Cell in Series � Estimation of Compressive Strength of High�...
Voltage Source Converter Technology for Offshore Grids.
??This master thesis has investigated the possible application of voltage source converters (VSC) for the interconnection of offshore installations, i.e. wind farms and petroleum platforms,� (more)
Vormedal, P�l Kristian Myhrer
Group 3: Humidity, Temperature, and Voltage (Presentation)
Group 3 is chartered to develop accelerated stress tests that can be used as comparative predictors of module lifetime versus stresses associated with humidity, temperature and voltage.
Pulsed voltage electrospray ion source and method for preventing analyte electrolysis
An electrospray ion source and method of operation includes the application of pulsed voltage to prevent electrolysis of analytes with a low electrochemical potential. The electrospray ion source can include an emitter, a counter electrode, and a power supply. The emitter can include a liquid conduit, a primary working electrode having a liquid contacting surface, and a spray tip, where the liquid conduit and the working electrode are in liquid communication. The counter electrode can be proximate to, but separated from, the spray tip. The power system can supply voltage to the working electrode in the form of a pulse wave, where the pulse wave oscillates between at least an energized voltage and a relaxation voltage. The relaxation duration of the relaxation voltage can range from 1 millisecond to 35 milliseconds. The pulse duration of the energized voltage can be less than 1 millisecond and the frequency of the pulse wave can range from 30 to 800 Hz.
Kertesz, Vilmos (Knoxville, TN); Van Berkel, Gary (Clinton, TN)
Energy-efficient datapath scheduling using multiple voltages and dynamic clocking
Recently, dynamic frequency scaling has been explored at the CPU and system levels for power optimization. Low-power datapath scheduling using multiple supply voltages has been well researched. In this work, we develop new datapath scheduling algorithms ... Keywords: High-level synthesis, dynamic frequency clocking, low-power datapath synthesis, multiple voltage scheduling, resource-constrained scheduling, time-constrained scheduling
Saraju P. Mohanty; N. Ranganathan
Current status of CMOS low voltage and low power wireless IC designs
This paper surveys recent research on CMOS low voltage and low power IC designs for wireless applications. Advancements and challenges in using nanometer IC processes are addressed, and the impacts of device scaling on wireless systems are discussed. ... Keywords: CMOS, Integrated Circuits (IC), Low-Power, Low-Voltage, Nanometer, Radio Frequency (RF), Sub-1V, Wireless
Tommy K. Tsang; Mourad N. El-Gamal; Krzysztof Iniewski; Kenneth A. Townsend; James W. Haslett; Yanjie Wang
Study on the operation of a low-voltage AC microgrid with multiple distributed generations
This paper aims to study the operation of a grid-connected low-voltage AC microgrid with multiple distributed generations (DGs). First of all, a 400 V low-voltage AC microgrid integrated with a 30 kW microturbine generator, a 13 kW photovoltaic generation ... Keywords: distributed generators, distribution systems, microgrids, steady-state analysis, three-phase power flow
Wei-Tzer Huang
Steady-state power flow modeling for a dynamic voltage restorer
This paper presents analysis, modeling and simulation of power distribution network performance incorporating with an installed dynamic voltage restorer (DVR). DVR is one of series compensators used in power distribution systems in order to maintain ... Keywords: Gauss-Seidel method, dynamic voltage restorer, modeling, power flow, simulation
T. Ratniyomchai; T. Kulworawanichpong
Capturing power at higher voltages from arrays of microbial fuel cells without voltage reversal
is too low to be used directly for many practical applications. For example, a single light emitting diode (LED) requires a minimum voltage of 2 V.2 Thus, effective methods of boosting MFC voltages
Aalborg Universitet Mitigation of Voltage Sags in CIGRE Low Voltage Distribution Network
software version 15.0. Index Terms--Wind Turbine Generator (WTG), Photovoltaic (PV), Voltage Source of voltage sags. I. INTRODUCTION Power quality, reliability and stability are the prime requirement of modern
Bak-Jensen, Birgitte
Nominations open for $250,000 Multimedia Clean Energy prizes | OpenEI
Nominations open for $250,000 Multimedia Clean Energy prizes Nominations open for $250,000 Multimedia Clean Energy prizes Home > Groups > Utility Rate Graham7781's picture Submitted by Graham7781(1992) Super contributor 2 October, 2012 - 13:01 American Clean Skies Foundation clean energy Energy Visions Prize OpenEI WASHINGTON, D.C. (September 27, 2012) - Representatives of the $250,000 Energy Visions Prize (EVP) competition will attend the Cleanweb Hackathons in NYC, Houston and SXSW Eco in Austin to preview innovative clean energy apps and encourage nominations. The EVP rewards innovative software and video makers who advance clean energy solutions. Based on growing national interest in the competition, the prize sponsor, the American Clean Skies Foundation (ACSF), also announced that it has extended the submission deadline until December 14, 2012.
Voltage regulation in linear induction accelerators
Improvement in voltage regulation in a Linear Induction Accelerator wherein a varistor, such as a metal oxide varistor when it is placed in parallel with the beam accelerating cavity and the magnetic core. The non-linear properties of the varistor result in a more stable voltage across the beam accelerating cavity than with a conventional compensating resistance.
Parsons, W.M.
Improvement in voltage regulation in a linear induction accelerator wherein a varistor, such as a metal oxide varistor, is placed in parallel with the beam accelerating cavity and the magnetic core is disclosed. The non-linear properties of the varistor result in a more stable voltage across the beam accelerating cavity than with a conventional compensating resistance. 4 figs.
High Voltage Safety Act | Department of Energy
High Voltage Safety Act High Voltage Safety Act High Voltage Safety Act < Back Eligibility Commercial Construction Developer General Public/Consumer Industrial Installer/Contractor Utility Savings Category Alternative Fuel Vehicles Hydrogen & Fuel Cells Buying & Making Electricity Water Home Weatherization Solar Wind Program Info State Georgia Program Type Safety and Operational Guidelines Siting and Permitting The purpose of the High Voltage Safety Act is to prevent injury to persons and property and interruptions of utility service resulting from accidental or inadvertent contact with high-voltage electric lines by providing that no work shall be done in the vicinity of such lines unless and until the owner or operator thereof has been notified of such work and has taken the appropriate safety measures. The Georgia Public Service Commission requires
Flexible method for monitoring fuel cell voltage
A method for equalizing the measured voltage of each cluster in a fuel cell stack wherein at least one of the clusters has a different number of cells than the identical number of cells in the remaining clusters by creating a pseudo voltage for the different cell numbered cluster. The average cell voltage of the all of the cells in the fuel cell stack is calculated and multiplied by a constant equal to the difference in the number of cells in the identical cell clusters and the number of cells in the different numbered cell cluster. The resultant product is added to the actual voltage measured across the different numbered cell cluster to create a pseudo voltage which is equivalent in cell number to the number of cells in the other identical numbered cell clusters.
Mowery, Kenneth D. (Noblesville, IN); Ripley, Eugene V. (Russiaville, IN)
Vehicle Details And Battery Specifications
Nominal Cell Voltage: 3.6 V Number of Electric Machines: 1 Nominal System Voltage: 144 V Motor: 17 kW (peak), Permanent Magnet, Liquid cooled Rated Pack Capacity: 4.7 Ah Maximum...
High Voltage MOSFET Gate/Bulk Driver Controller for a Microbattery Switch Matrix in a 0.35 �m Microwave SOI Technology
Integrated microbatteries are being currently developed to act as a "micropower" source in microsatellites. The current and voltage rating of the microbattery is fixed. Certain highly miniaturized systems require higher voltages and currents. A switching ... Keywords: LDMOSFET, SOI, microbattery, micropower
Vinesh Sukumar; Mahmoud Alahmad; Kevin Buck; Herbert Hess; Harry Li; Dave Cox; Fadi Nessir Zghoul; Jeremy Jackson; Stephen Terry; Ben Blalock; M. M. Mojarradi; W. C. West; J. F. Whitacre
Optically triggered high voltage switch network and method for switching a high voltage
An optically triggered solid state switch and method for switching a high voltage electrical current. A plurality of solid state switches (350) are connected in series for controlling electrical current flow between a compensation capacitor (112) and ground in a reactive power compensator (50, 50') that monitors the voltage and current flowing through each of three distribution lines (52a, 52b and 52c), which are supplying three-phase power to one or more inductive loads. An optical transmitter (100) controlled by the reactive power compensation system produces light pulses that are conveyed over optical fibers (102) to a switch driver (110') that includes a plurality of series connected optical triger circuits (288). Each of the optical trigger circuits controls a pair of the solid state switches and includes a plurality of series connected resistors (294, 326, 330, and 334) that equalize or balance the potential across the plurality of trigger circuits. The trigger circuits are connected to one of the distribution lines through a trigger capacitor (340). In each switch driver, the light signals activate a phototransistor (300) so that an electrical current flows from one of the energy reservoir capacitors through a pulse transformer (306) in the trigger circuit, producing gate signals that turn on the pair of serially connected solid state switches (350).
El-Sharkawi, Mohamed A. (Renton, WA); Andexler, George (Everett, WA); Silberkleit, Lee I. (Mountlake Terrace, WA)
Low-voltage cathodoluminescence of europium-activated yttrium orthovanadate
Emissive flat panel display systems operating in full color demand higher performance at low voltages (ca. 501000 V) from cathodoluminescent (CL) phosphors than cathode ray tubes require. Hydrothermal synthesis has been suggested as a route to phosphors with improved efficiencies, lower voltage thresholds, and increased saturation power. This hypothesis was tested in europium-doped yttrium orthovanadate (YVO{sub 4}:Eu), an efficient, red emitting CL phosphor. The CL efficiency of YVO{sub 4}:Eu crystallized from aqueous solution at 200{degrees}C is relatively low until it is annealed. The distribution of particle sizes in the low-temperature phosphor is similar to that in material made via a solid-state route, but crystallites remain much smaller (ca. 400 {Angstrom}) until they are annealed. These observations, along with the anomalously strong dependence of CL intensity on europium concentration, support a model in which efficiency principally depends on crystallite size. CL efficiency of both solid state and hydrothermal YVO{sub 4}:Eu increases with voltage at constant power. Surface-bound electrons are likely the dominant influence on efficiency at voltages near threshold. Saturation power is independent of synthetic route. It is apparent that the CL properties of hydrothermally synthesized YVO{sub 4}:Eu are essentially the same as those of YVO{sub 4}:Eu produced via conventional, high-temperature routes.
Phillips, M.L.F.
Voltage stability/security assessment and on-line control
Project RP3040-1 was initiated in 1989, and concluded with the release of the Voltage Stability analysis program, VSTAB, in 1992. VSTAB is a production grade program for voltage stability assessment of large complex power systems. During the course of the RP3040-1, much effort was spent in developing a clear understanding of voltage stability and in defining the special modeling and analytical techniques required to accurately capture the phenomenon through simulation. The result was the development of new steady state methods which can complement the dynamic simulation methods currently available with EPRI's Extended Transient/Midterm Stability Program (ETMSP). VSTAB uses an enhanced powerflow combined with a specially developed modal analysis algorithm to provide information regarding both the proximity to, and mechanism of, voltage instability. The program is fast, easy to use, and comprehensive in both modeling and analysis features. This Programmer's Manual documents the structure and code details of VSTAB. It is intended as a reference document for those required to maintain or enhance the VSTAB program. For details on analytical techniques used in the program, readers are directed to the VSTAB Application Guide and Final Report for project RP3040-1.
Morison, G.K.; Gao, B.; Hamadanizadeh, H. (Ontario Hydro, Toronto, ON (Canada))
U.S. Nominal Cost per Foot of Dry Wells Drilled (Dollars per...
Dry Wells Drilled (Dollars per Foot) U.S. Nominal Cost per Foot of Dry Wells Drilled (Dollars per Foot) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5 Year-6 Year-7 Year-8 Year-9...
Application / Nomination Form TIAA-CREF Ruth Simms Hamilton Graduate Merit Fellowship
Application / Nomination Form for TIAA-CREF Ruth Simms Hamilton Graduate Merit Fellowship 2013 the subject line reads "TIAA-CREF Fellowship Application (applicant's name)". Questions? Please contact Dean Klomparens (firstname.lastname@example.com). The Fellowship award will be announced by mid-January, 2014. The TIAA
Liu, Taosheng
Voltage controlled spintronics device for logic applications.
We consider logic device concepts based on our previously proposed spintronics device element whose magnetization orientation is controlled by application of a bias voltage instead of a magnetic field. The basic building block is the voltage-controlled rotation (VCR) element that consists of a four-layer structure--two ferromagnetic layers separated by both nanometer-thick insulator and metallic spacer layers. The interlayer exchange coupling between the two ferromagnetic layers oscillates as a function of applied voltage. We illustrate transistor-like concepts and re-programmable logic gates based on VCR elements.
Bader, S. D.; You, C.-Y.
Voltage controlled spintronic devices for logic applications
We consider logic device concepts based on our previously proposed spintronics device element whose magnetization orientation is controlled by application of a bias voltage instead of a magnetic field. The basic building block is the voltage-controlled rotation (VCR) element that consists of a four-layer structure--two ferromagnetic layers separated by both nanometer-thick insulator and metallic spacer layers. The interlayer exchange coupling between the two ferromagnetic layers oscillates as a function of applied voltage. We illustrate transistorlike concepts and reprogrammable logic gates based on VCR elements. (c) 2000 American Institute of Physics.
You, Chun-Yeol [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Bader, S. D. [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
Interphase power controller with voltage injection
This paper introduces a new family of Interphase Power Controllers (IPC) based on the principle of voltage injection commonly used in phase-shifting transformers (PST). The voltage injection IPC exhibits power (active and reactive) control characteristics similar to previously defined IPC's and retains their inherent qualities: passive control, short circuit limitation and voltage decoupling. It also provides more flexibility for the adjustment of the operating points. Two promising topologies are described in more detail. One of them offers the potential of retrofitting existing phase-shifting transformers into full-fledged IPC's.
Beauregard, F.; Brochu, J.; Morin, G.; Pelletier, P. (Centre d'Innovation sur le Transport d'Energie du Quebec, Varennes, Quebec (Canada))
Performance of a voltage peak detection-based flickermeter
Voltage fluctuations and rapid voltage changes lead to lamps flickering and disturbance of visual perception may occur consequently. For evaluation of the flicker severity level by means of voltage measurement there was developed an instrument called ... Keywords: Matlab Simulink, flickermeter, interharmonics, performance analysis, voltage fluctuation, voltage peak detection
Jiri Drapela
High Voltage Test Apparatus for a Neutron EDM Experiment and Lower Limit on the Dielectric Strength of Liquid Helium at Large Volumes
A new search for a permanent electric dipole moment (EDM) of the neutron is underway using ultracold neutrons produced and held in a bath of superfluid helium. Attaining the target sensitivity requires maintaining an electric field of several tens of kilovolts per centimeter across the experimental cell, which is nominally 7.5 cm wide and will contain about 4 liters of superfluid. The electrical properties of liquid helium are expected to be sufficient to meet the design goals, but little is known about these properties for volumes and electrode spacings appropriate to the EDM experiment. Furthermore, direct application of the necessary voltages from an external source to the experimental test cell is impractical. An apparatus to amplify voltages in the liquid helium environment and to test the electrical properties of the liquid for large volumes and electrode spacings has been constructed. The device consists of a large-area parallel plate capacitor immersed in a 200 liter liquid helium dewar. Preliminary results show the breakdown strength of normal state liquid helium is at least 90 kV/cm at these volumes, at the helium vapor pressure corresponding to 4.38 K. These fields hold for more than 11 hours with leakage currents less than 170 pA (about 20% of the maximum tolerable in the EDM experiment). The system is also found to be robust against anticipated radiation backgrounds. Preliminary results for superfluid show that fields of at least 30 kV/cm can be sustained at the volumes required for the EDM experiment, about 60% of the design goal. These results are likely limited by the low pressure that must be maintained above the superfluid bath.
J. C. Long; P. D. Barnes; J. G. Boissevain; D. J. Clark; M. D. Cooper; J. J. Gomez; S. K. Lamoreaux; R. E. Mischke; S. I. Penttila
Operational Results of Pulse Shaping Techniques for the High Voltage Convertor Modulator
The High Voltage Converter Modulators (HVCMs) are used to power the RF klystrons used throughout the accelerator systems at Spallation Neutron Source (SNS). The output voltage of the HVCM has significant droop and ripple which, combined with low level RF (LLRF) system limitations, affect performance and efficiency of accelerator cavities. In conjunction with the progress in development of the new HVCM controller, different pulse modulation techniques were implemented and studied on the test modulator. This paper discusses the results of implementation of frequency modulation and phase modulation on output voltage. Operational data, including full average power operation, of test modulator is also discussed. Future plans for the new modulation scheme will be presented.
Patel, Gunjan P [ORNL; Anderson, David E [ORNL; Solley, Dennis J [ORNL; Wezensky, Mark W [ORNL
Fault-Delayed Voltage Recovery Control with Plug-In Hybrid Electric Vehicles
This paper presents an investigation into the impact that plug-in hybrid electric vehicles (PHEVs) could have to mitigate the effects of fault-delayed voltage recovery. The energy storage and conversion system in PHEVs, given potentially high levels ...
Curtis Roe; Yousef M. Al-Abdullah; Dhwanil Desai; George K. Stefopoulos; George J. Cokkinides; A. P. Meliopoulos
The EP-4(0) shielding kits: a new approach to protection from induced voltage
Problems of safety in work on overhead power lines and the overhead railroad ac contact network under induced voltages are considered. The use of additional individual protection systems is proposed to provide protection from electric shock during such work.
Vorob'ev, A. Yu.; Otmorskii, S. G.; Smekalov, V. V.; Gorozhankina, E. N.; Sosunov, N. N.; Bol'shunov, A. M.
Field Guide: Compressors for High-Voltage Circuit Breakers
High-voltage circuit breakers (HVCBs) perform essential protection and control functions on power transmission networks. Circuit breakers have multiple components that must operate in concert in order for the breaker to perform properly. If one component, such as the air or hydraulic system, does not operate correctly, the circuit breaker may misoperate or fail, possibly resulting in equipment damage or an outageboth expensive consequences. To help utilities prevent such undesirable events, this field gu...
High-voltage circuit breakers (HVCBs) perform essential protection and control functions on power transmission networks. Circuit breakers have multiple components that must operate in concert in order for the breaker to perform properly. If one component, such as the air or hydraulic system, does not operate correctly, the circuit breaker may misoperate or fail, possibly resulting in equipment damage or an outage�both expensive consequences. To help ...
High Voltage Direct Current (HVDC) Transmission Reference Book
The EPRI High-Voltage Direct Current (HVDC) Transmission Reference Book is a state-of-the-art guidebook that provides transmission companies with a comprehensive, single source of technical information and guidance for designing, building, operating, and extending the life of HVDC transmission systems. The book joins the landmark series of EPRI power delivery reference books. These comprehensive guidebooks�each printed with a distinctive colored cover�document and distill the ...
High-Voltage Direct Current Line Conductor Optimization
Overhead transmission lines are designed to last for 40 years. Many ac lines in service today in North America are 70 or more years old. This survival rate is a result of conservative utility design practices and detailed product specifications. This reliability record has occurred despite a wide range of conductor types and sizes. In the present transmission system, there are far fewer high-voltage direct current (HVDC) lines, but those that have been designed and built have been similarly successful in...
Field Guide: High-Voltage Circuit Breaker Compressors � 2013 Update
High-voltage circuit breakers (HVCBs) perform essential protection and control functions on power transmission networks. Circuit breaker mechanisms have multiple components that must operate in concert in order for the breaker to perform properly. If one component, such as the air or hydraulic system, does not operate correctly, the circuit breaker may mis-operate or fail. A circuit breaker mis-operation may cause equipment damage and outages�both ...
Advanced Voltage Control Strategies for High Penetration of Distributed Generation
This research addresses advanced voltage control strategies for inverter-connected distributed generation. The emphasis is on photovoltaic (PV) generation, and results also apply to distributed wind, fuel cells, micro-turbines, and battery systems that are connected to the grid through an inverter. In related work, the Electric Power Research Institute (EPRI) identified a set of high-priority functions for distributed generation. These included reactive power control such as intelligent and autonomous vo...
Contaminated Outdoor High Voltage Insulators
The external insulation of power lines and outdoor substations is a weak point in transmission systems. The insulation is particularly susceptible to failure if proper attention has not been given to its design, condition monitoring, and maintenance. In regions with high contamination levels, regular maintenance and the application of palliative measures can be critical to ensure that the system meets its outage performance targets. This can involve pure maintenance measures such as cleaning the insulato...
Low voltage arc formation in railguns
A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile.
Hawke, R.S.
Hawke, Ronald S. (Livermore, CA)
A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile. 2 figs.
We describe charge-coupled device (CCD) developmentactivities at the Lawrence Berkeley National Laboratory (LBNL).Back-illuminated CCDs fabricated on 200-300 mu m thick, fully depleted,high-resistivity silicon substrates are produced in partnership with acommercial CCD foundry.The CCDs are fully depleted by the application ofa substrate bias voltage. Spatial resolution considerations requireoperation of thick, fully depleted CCDs at high substrate bias voltages.We have developed CCDs that are compatible with substrate bias voltagesof at least 200V. This improves spatial resolution for a given thickness,and allows for full depletion of thicker CCDs than previously considered.We have demonstrated full depletion of 650-675 mu m thick CCDs, withpotential applications in direct x-ray detection. In this work we discussthe issues related to high-voltage operation of fully depleted CCDs, aswell as experimental results on high-voltage-compatible CCDs.
Holland, Stephen E.; Bebek, Chris J.; Dawson, Kyle S.; Emes, JohnE.; Fabricius, Max H.; Fairfield, Jessaym A.; Groom, Don E.; Karcher, A.; Kolbe, William F.; Palaio, Nick P.; Roe, Natalie A.; Wang, Guobin
Spark gap with low breakdown voltage jitter
Novel spark gap devices and electrodes are disclosed. The novel spark gap devices and electrodes are suitable for use in a variety of spark gap device applications. The shape of the electrodes gives rise to local field enhancements and reduces breakdown voltage jitter. Breakdown voltage jitter of approximately 5% has been measured in spark gaps according the invention. Novel electrode geometries and materials are disclosed.
Rohwein, Gerald J. (Albuquerque, NM); Roose, Lars D. (Albuquerque, NM)
Voltage Control Optimization to Improve Transmission Efficiency
An optimal power flow solution is unique from a conventional power flow solution in that an objective function and user-specified constraints are enforced and satisfied to reach a valid solution. This report presents an analytical study on the optimization of power flow in order to minimize reactive power losses via the modification of generator voltage schedules and transmission switched shunt status. The study examines the potential benefits and applicability of near-real-time voltage control ...
Current-Voltage Characteristics of Bi-dithiolbenzene in Parallel Arrangement
The low voltage conductance of interacting two 1,4-dithiolbenzene (DTB) molecules is investigated. The simulation results show that the electron transport can be controlled either by changing the Fermi level position E{sub f} or modifying its inter-molecular spacing d. Molecular assembly system with close interaction between DTB units, affects significantly the conductance. In addition, the position of the Fermi plays an important role in determining the current flow. Moreover, it is important to note that E{sub f} affects not only the threshold voltage V{sub th}, but also the saturation voltage V{sub sat}. When E{sub f} approaches the LUMO energy level, V{sub th} decreases, while V{sub sat} increases. To conclude, the threshold voltage and the saturation voltage depend on the Fermi level position and the inter-molecular spacing.
Boudjella, Aissa [Department of Computer and Communication Technolgy, Faculty of Information and communication, Technology, University Tunku Abdul Rahman, Jalan University, Bandar Barat, 31900 Kampar, Perak (Malaysia)
Identification of Critical Voltage Control Areas (VCA) Version 3.1
Identify the weak sub-system and the requirement of reactive power reserves The objective of this research project is to investigate and develop a methodology for identifying areas in power systems that are prone to voltage instability under particular operating conditions and contingencies. These areas, which are prone to instability due to their lack of reactive power reserves, are referred to as voltage control areas (VCAs). Once VCAs are identified, methods of determining their adequate reactive powe...
Identification of Critical Voltage Control Areas and Determination of Required Reactive Power Reserves
This Technical Update reports on the development of a highly automated method for identifying Voltage Control Areas (VCAs), areas prone to voltage instability in practical power system models. For a wide range of system conditions and contingencies, the technique can identify the buses in each VCA and identify VCAs that are common for a set of contingencies and/or conditions. In addition, the method identifies the generators that are critical to maintaining stability for a given VCA. The methods develope...
The objective of this research project is to investigate and devise a methodology for identifying areas in power systems that are prone to voltage instability under particular operating conditions and contingencies. These areas, which are prone to instability due to their lack of reactive power reserves, are referred to as critical voltage control areas (VCAs). Once VCAs are identified, methods of determining their adequate reactive power reserve requirements to ensure secure system operation under all c...
Technology Assessment and Application Guide for an Active Voltage Conditioner with Storage Option (AVC-Store)
This report describes and documents the construction, performance, and application of an active voltage conditioner (AVC) with energy storage. The system8211called the AVC-Store8211is manufactured by Vectek in Napier, New Zealand. Composed of a novel power electronics module, the system is organized to mitigate voltage sags, phase shift, and outages. This report describes the various subsystems within the AVC-Store, its operation, results of characterization tests, and issues related to its application a...
FirstEnergy Uses EPRI Interregional Reactive Power Management Framework to Help Improve Transmission Voltage Stability
FirstEnergy teamed with EPRI and Powertech Labs to develop a practical, automated method for identifying areas prone to voltage instability due to a lack of reactive power reserves. Power system designers and operational planning engineers can use the new method to evaluate the performance of various power system designs or configurations with regard to susceptibility to voltage instability, determine weak areas requiring special remediation, and maximize the efficient use of assets by determining the mi...
Grid Strategy 2011: Conservation Voltage Reduction and Volt VAR Optimization in the Smart Grid
Beginning in the 1970s with the oil embargo, utilities began looking for ways to increase the efficiency of the power distribution system, to reduce peak demand, and to conserve energy. During this period, several utilities began to test the concept of lowering the voltage to lower the demand and energy consumption on the power delivery system. As climate change and global warming became serious issues in the early 2000s, utilities began looking at Conservation Voltage Reduction (CVR) programs once again...
... secondary technical training model for public schools in cyber security, biomedical and engineering, including aerospace, biotech, digital, civil and ...
Cell Voltage Noise Reduction Based on Wavelet in Aluminum ...
Presentation Title, Cell Voltage Noise Reduction Based on Wavelet in Aluminum ... cell voltage signals collected in aluminium electrolysis process are with high�...
Dynamic Simulation of Cell Voltage Resonance Effect in Aluminum ...
Dubal Cell Voltage Drop Initiatives towards Low Energy High Amperage Cells � Dynamic Simulation of Cell Voltage Resonance Effect in Aluminum Electrolysis�...
Appendix C: California ISO Real Time Voltage Security Assessment...
C: California ISO Real Time Voltage Security Assessment (VSA) Prototype Functional SpecificationsPrototype Development Title Appendix C: California ISO Real Time Voltage Security...
Appendix B: California ISO Real Time Voltage Security Assessment...
B: California ISO Real Time Voltage Security Assessment (VSA) Summary Report Title Appendix B: California ISO Real Time Voltage Security Assessment (VSA) Summary Report Publication...
Appendix A: California ISO Real Time Voltage Security Assessment...
A: California ISO Real Time Voltage Security Assessment (VSA) Project: Summary of Survey Results on Methodologies for use in Real-Time Voltage Security Assessment Title Appendix A:...
Incorporating voltage security into the planning, operation and monitoring of restructured electric energy markets
As open access market principles are applied to power systems, significant changes are happening in their planning, operation and control. In the emerging marketplace, systems are operating under higher loading conditions as markets focus greater attention to operating costs than stability and security margins. Since operating stability is a basic requirement for any power system, there is need for newer tools to ensure stability and security margins being strictly enforced in the competitive marketplace. This dissertation investigates issues associated with incorporating voltage security into the unbundled operating environment of electricity markets. It includes addressing voltage security in the monitoring, operational and planning horizons of restructured power system. This dissertation presents a new decomposition procedure to estimate voltage security usage by transactions. The procedure follows physical law and uses an index that can be monitored knowing the state of the system. The expression derived is based on composite market coordination models that have both PoolCo and OpCo transactions, in a shared stressed transmission grid. Our procedure is able to equitably distinguish the impacts of individual transactions on voltage stability, at load buses, in a simple and fast manner. This dissertation formulates a new voltage stability constrained optimal power flow (VSCOPF) using a simple voltage security index. In modern planning, composite power system reliability analysis that encompasses both adequacy and security issues is being developed. We have illustrated the applicability of our VSCOPF into composite reliability analysis. This dissertation also delves into the various applications of voltage security index. Increasingly, FACT devices are being used in restructured markets to mitigate a variety of operational problems. Their control effects on voltage security would be demonstrated using our VSCOPF procedure. Further, this dissertation investigates the application of steady state voltage stability index to detect potential dynamic voltage collapse. Finally, this dissertation examines developments in representation, standardization, communication and exchange of power system data. Power system data is the key input to all analytical engines for system operation, monitoring and control. Data exchange and dissemination could impact voltage security evaluation and therefore needs to be critically examined.
Nair, Nirmal-Kumar
A multilevel voltage-source inverter with separate dc sources for static var generation
A new multilevel voltage-source inverter with a separate dc sources is proposed for high-voltage, high-power applications, such as flexible ac transmission systems (FACTS) including static var generation (SVG), power line conditioning, series compensation, phase shifting, voltage balancing, fuel cell and photovoltaic utility systems interfacing, etc. The new M-level inverter consists of (M-1)/2 single phase full bridges in which each bridge has its own separate dc source. This inverter can generate almost sinusoidal waveform voltage with only one time switching per cycle as the number of levels increases. It can solve the problems of conventional transformer-based multipulse inverters and the problems of the multilevel diode-clamped inverter and the multilevel flying capacitor inverter. To demonstrate the superiority of the new inverter, a SVG system using the new inverter topology is discussed through analysis, simulation and experiment.
Peng, Fang Zheng [Tennessee Univ., Knoxville, TN (United States)]|[Oak Ridge National Lab., TN (United States); Lai, Jih-Sheng; McKeever, J.; VanCoevering, J. [Oak Ridge National Lab., TN (United States)
Evaluation of Conservation Voltage Reduction (CVR) on a National Level
Conservation Voltage Reduction (CVR) is a reduction of energy consumption resulting from a reduction of feeder voltage. While there have been numerous CVR systems deployed in North America there has been little substantive analytic analysis of the effect; the majority of the published results are based on empirical field measurements. Since these results are based on empirical measurements it is difficult to extrapolate how this technology will behave on the various types of distribution feeders found throughout the nation. This report has utilized the Taxonomy of Prototypical feeder developed under the Modern Grid Initiative (MGI), now the Modern Grid Strategy (MGS), in order to estimate the benefits of CVR on multiple distribution feeder types. This information will then be used to determine an estimate of the national benefits of a wide scale deployment of CVR.
Schneider, Kevin P.; Fuller, Jason C.; Tuffner, Francis K.; Singh, Ruchi
Strategies for Voltage Control and Transient Stability Assessment
As wind generation grows, its influence on power system performance will becoming increasingly noticeable. Wind generation di#11;ffers from traditional forms of generation in numerous ways though, motivating the need to reconsider the usual approaches to power system assessment and performance enhancement. The project has investigated the impact of wind generation on transient stability and voltage control, identifying and addressing issues at three distinct levels of the power system: 1) at the device level, the physical characteristics of wind turbine generators (WTGs) are quite unlike those of synchronous machines, 2) at the wind-farm level, the provision of reactive support is achieved through coordination of numerous dissimilar devices, rather than straightforward generator control, and 3) from a systems perspective, the location of wind-farms on the sub-transmission network, coupled with the variability inherent in their power output, can cause complex voltage control issues. The project has sought to develop a thorough understanding of the dynamic behaviour of type-3 WTGs, and in particular the WECC generic model. The behaviour of such models is governed by interactions between the continuous dynamics of state variables and discrete events associated with limits. It was shown that these interactions can be quite complex, and may lead to switching deadlock that prevents continuation of the trajectory. Switching hysteresis was proposed for eliminating deadlock situations. Various type-3 WTG models include control blocks that duplicate integrators. It was shown that this leads to non-uniqueness in the conditions governing steady-state, and may result in pre- and post-disturbance equilibria not coinciding. It also gives rise to a zero eigenvalue in the linearized WTG model. In order to eliminate the anomalous behaviour revealed through this investigation, WECC has now released a new generic model for type-3 WTGs. Wind-farms typically incorporate a variety of voltage control equipment including tapchanging transformers, switched capacitors, SVCs, STATCOMs and the WTGs themselves. The project has considered the coordinated control of this equipment, and has addressed a range of issues that arise in wind-farm operation. The #12;first concerns the ability of WTGs to meet reactive power requirements when voltage saturation in the collector network restricts the reactive power availability of individual generators. Secondly, dynamic interactions between voltage regulating devices have been investigated. It was found that under certain realistic conditions, tap-changing transformers may exhibit instability. In order to meet cost, maintenance, fault tolerance and other requirements, it is desirable for voltage control equipment to be treated as an integrated system rather than as independent devices. The resulting high-level scheduling of wind-farm reactive support has been investigated. In addressing this control problem, several forms of future information were considered, including exact future knowledge and stochastic predictions. Deterministic and Stochastic Dynamic Programming techniques were used in the development of control algorithms. The results demonstrated that while exact future knowledge is very useful, simple prediction methods yield little bene#12;fit. The integration of inherently variable wind generation into weak grids, particularly subtransmission networks that are characterized by low X=R ratios, aff#11;ects bus voltages, regulating devices and line flows. The meshed structure of these networks adds to the complexity, especially when wind generation is distributed across multiple nodes. A range of techniques have been considered for analyzing the impact of wind variability on weak grids. Sensitivity analysis, based on the power-flow Jacobian, was used to highlight sections of a system that are most severely a#11;ffected by wind-power variations. A continuation power flow was used to determine parameter changes that reduce the impact of wind-power variability. It was also used to explore interactions betw
Hiskens, Ian A.
A method for reducing harmonics in output voltages of a double-connected inverter
A new method for reducing harmonics involved in output voltages of the double-connected inverter is proposed. By adding four auxiliary switching devices and an interphase transformer with secondary winding to the conventional 12-step inverter, output voltages of the proposed circuit can be almost the same waveforms as a conventional 36-step inverter. In this paper, circuit performances and output voltage waveforms are discussed, and the optimum parameters are derived. Then, effects on harmonic reductions can be clarified by theoretical and experimental results, and ratings of system components are investigated.
Masukawa, Shigeo; Iida, Shoji (Tokyo Denki Univ., Tokyo (Japan). Dept. of Electrical Engineering)
CH2M HILL Hanford Group, Inc. (CH2M HILL) is pleased to nominate the Integrated Disposal Facility (IDF) project for the Project Management Institute's consideration as 2007 Project of the Year, Built for the U.S, Department of Energy's (DOE) Office of River Protection (ORP) at the Hanford Site, the IDF is the site's first Resource Conservation and Recovery Act (RCRA)-compliant disposal facility. The IDF is important to DOE's waste management strategy for the site. Effective management of the IDF project contributed to the project's success. The project was carefully managed to meet three Tri-Party Agreement (TPA) milestones. The completed facility fully satisfied the needs and expectations of the client, regulators and stakeholders. Ultimately, the project, initially estimated to require 48 months and $33.9 million to build, was completed four months ahead of schedule and $11.1 million under budget. DOE directed construction of the IDF to provide additional capacity for disposing of low-level radioactive and mixed (i.e., radioactive and hazardous) solid waste. The facility needed to comply with federal and Washington State environmental laws and meet TPA milestones. The facility had to accommodate over one million cubic yards of the waste material, including immobilized low-activity waste packages from the Waste Treatment Plant (WTP), low-level and mixed low-level waste from WTP failed melters, and alternative immobilized low-activity waste forms, such as bulk-vitrified waste. CH2M HILL designed and constructed a disposal facility with a redundant system of containment barriers and a sophisticated leak-detection system. Built on a 168-area, the facility's construction met all regulatory requirements. The facility's containment system actually exceeds the state's environmental requirements for a hazardous waste landfill. Effective management of the IDF construction project required working through highly political and legal issues as well as challenges with permitting, scheduling, costs, stakeholders and technical issues. To meet the customer's needs and deadlines, the project was managed with conscientious discipline and application of sound project management principles in the Project Management Institute's Project Management Body of Knowledge. Several factors contributed to project success. Extensive planning and preparation were conducted, which was instrumental to contract and procurement management. Anticipating issues and risks, CH2M HILL prepared well defined scope and expectations, particularly for safety. To ensure worker safety, the project management team incorporated CH2M HILL's Integrated Safety Management System (ISMS) into the project and included safety requirements in contracting documents and baseline planning. The construction contractor DelHur Industries, Inc. adopted CH2M HILL's safety program to meet the procurement requirement for a comparable ISMS safety program. This project management approach contributed to an excellent safety record for a project with heavy equipment in constant motion and 63,555 man-hours worked. The project manager worked closely with ORP and Ecology to keep them involved in project decisions and head off any stakeholder or regulatory concerns. As issues emerged, the project manager addressed them expeditiously to maintain a rigorous schedule. Subcontractors and project contributors were held to contract commitments for performance of the work scope and requirements for quality, budget and schedule. Another element of project success extended to early and continual involvement of all interested in the project scope. Due to the public sensitivity of constructing a landfill planned for radioactive waste as well as offsite waste, there were many stakeholders and it was important to secure their agreement on scope and time frames. The project had multiple participants involved in quality assurance surveillances, audits and inspections, including the construction contractor, CH2M HILL, ORP, the Washington State Department of Ecology, and independent certified quality assurance an
Cascode buffer for monolithic voltage conversion operating at high input supply voltages
A high-to-low switching DC-DC converter that operates at input supply voltages up to two times as high as the maximum voltage permitted in a nanometer CMOS technology is proposed in this paper. The circuit technique is based on a cascode bridge that maintains the steady-state voltage differences among the terminals of all of the transistors within a range imposed by a specific fabrication technology. The proposed circuit technique permits the full integration of active and passive devices of a switching DC-DC converter with a high voltage conversion ratio in a standard low voltage CMOS process. An efficiency of 87.8 % is achieved for 3.6 volts to 0.9 volts conversion assuming
Volkan Kursun; Gerhard Schrom; Vivek K. De; Eby G. Friedman; Siva G. Narendra
An Electronic Voltage Transformer Based on WLAN Technology
An electronic voltage transformer based on WLAN technology is developed for adapting to the development trends of substations� synthesis automation. The transformer is composed of voltage-to-current conversion unit, signal processing unit and data ... Keywords: electronic voltage transformer, voltage-to-current conversion, WLAN technology, digital interface, wireless communication
Jianqin Feng; Qingming Wang; Fen Niu; Guangzhao Cui; Anping Zheng
Motor voltage high harmonics influence to efficient energy usage
Analysis of the effect of non-sinusoidal voltages on the three-phase induction motor is presented in the paper. When the induction motors are supplied by a rectangular shape of the voltage inverter with high levels of harmonic voltage (Uh,i ... Keywords: energy efficiency, harmonics, induction motor, non-sinusoidal voltage, power losses
Miloje M. Kostic; Branka B. Kostic
Analysis of Voltage Rise Effect on Distribution Network with Distributed
appearance of hidden loads and affect the voltage profile of low voltage distribution network. To overcomeAnalysis of Voltage Rise Effect on Distribution Network with Distributed Generation M. A. Mahmud. This paper presents a detail analysis of how does voltage rise on distribution network due to the penetration
Computer Simulation of 132 / 11 KV Distribution Substation Using Static Var Compensator (SVC) for Voltage Enhancement - A Case Study
With the change in transmitted load in power system, reactive power varies accordingly, which may result into unacceptable voltage variation. This affects the performance of power system parameters like power loss and power factor. This paper deals with ...
M. J. Katira; K. B. Porate
Understanding the unbalanced-voltage problem in wind turbine generation
Most wind turbines are equipped with line-connected induction generators. Induction generators are very attractive as wind turbine generators due to their low cost, ruggedness and the need for little or no maintenance. At constant frequency, the induction generator operates in a small range of speeds and, therefore, it operated with a small range of slips with respect to synchronous speed. Compared to a synchronous generator, an induction generator provides lower stiffness, thus alleviating the mechanical stress. In a weak power system network, an unbalanced load at the distribution lines can cause unbalanced voltage conditions. If an induction generator is connected to an unbalanced voltage, the resulting stator current will be unbalanced. The unbalanced current creates unequal heating (hot spots) on the stator winding. The heat may increase the winding temperature, which degrades the insulation of the winding, i.e., the life expectancy of the winding. Unbalanced currents also create torque pulsation on the shaft resulting in audible noise and extra mechanical stress. This paper explores the unbalanced voltage problem in induction generators. The levels of unbalance and the loads are varied. Experimental and predicted results are presented in this paper.
Muljadi, E.; Butterfield, C.P.; Batan, T.; Yildirim, D.
Electronic circuit for measuring series connected electrochemical cell voltages
An electronic circuit for measuring voltage signals in an energy storage device is disclosed. The electronic circuit includes a plurality of energy storage cells forming the energy storage device. A voltage divider circuit is connected to at least one of the energy storage cells. A current regulating circuit is provided for regulating the current through the voltage divider circuit. A voltage measurement node is associated with the voltage divider circuit for producing a voltage signal which is proportional to the voltage across the energy storage cell.
Ashtiani, Cyrus N. (West Bloomfield, MI); Stuart, Thomas A. (Toledo, OH)
Design and characterization of a 0.35 micron CMOS voltage-to-current converter
This work presents the design and characterization of a CMOS voltage-to-current (V-I) converter with a current range from -100 ?A to 100 ?A. The V-I converter has a power consumption of approximately 0.6 mW and its final area was 0.022 mm2 ... Keywords: current reference, system on chip, voltage-to-current converter
Genival Mariano de Araujo; Heider Marconi G. Madureira; Jos� Camargo da Costa
Monitoring System Performance (Presentation)
Requirements for a standard test to rate the durability of photovoltaic (PV) modules at system voltage are discussed.
Emery, K.; Smith, R.
Group 3: Humidity, Temperature and Voltage (Presentation)
This is a summary of the work of Group 3 of the International PV QA Task Force. Group 3 is chartered to develop accelerated stress tests that can be used as comparative predictors of module lifetime versus stresses associated with humidity, temperature and voltage.
High voltage VLF testing of power cables
This publication describes a laboratory test program conducted with the objective to develop a test that would replace the existing dc withstand test. The article describes the methodology used to establish the voltage duration and magnitude of VLF (0.1 Hz) high voltage field tests suitable for crosslinked polyethylene (XLPE) insulated power cable. The results show that the voltage breakdown of laboratory aged XLPE cable at 0.1 Hz is approximately equal to that at 60 Hz, that proof tests at 0.1 Hz is approximately equal to that at 60 Hz, that proof tests at 0.1 Hz cause very little damage to the cable, and that 0.1 Hz testing appears to be a satisfactory alternate to dc testing. Preliminary values are suggested for voltage magnitude and time duration of cable acceptance, maintenance and proof tests at 0.1 Hz for XLPE cable rated up to 35 kV. A program is underway to similarly evaluate samples of service-aged XLPE cable; as well as to demonstrate the use of the preliminary test values at typical utility installations.
Eager, G.S.; Katz, C.; Fryszczyn, B. [Cable Technology Labs., Inc., New Brunswick, NJ (United States); Densley, J. [Ontario Hydro, Toronto, Ontario (Canada); Bernstein, B.S. [EPRI, Washington, DC (United States)
Cost of Providing Ancillary Services from Power Plants: Reactive Supply and Voltage Control
This report provides a methodology for determining the variable costs of generating and supplying reactive power to a transmission system, via the generator step-up transformer, for system voltage control. The report examines the costs of additional energy losses, maintenance, repair, and plant aging associated with the generation of reactive power. TR-107270-V3SI contains System of International units.
Cooperative frequency control with a multi-terminal high-voltage DC network
We consider frequency control in power systems made of several non-synchronous AC areas connected by a multi-terminal high-voltage direct current (HVDC) grid. We propose two HVDC control schemes to make the areas collectively react to power imbalances, ... Keywords: Decentralized control, Frequency control, HVDC systems, Power system control
Alain Sarlette; Jing Dai; Yannick Phulpin; Damien Ernst
Investigating different passive methods for enhancement of low voltage ride through capability of Doubly Fed Induction Generator
In recent years with the increasing use of wind generators in power systems the issue of keeping these generators stable and maintaining their connection to the network in the presence of fault or voltage sag has gained a great importance. In this paper some enhancement methods for the low voltage ride through of Doubly Fed Induction Generator (DFIG)
A capacitor-less low drop-out voltage regulator with fast transient response
Power management has had an ever increasing role in the present electronic industry. Battery powered and handheld applications require power management techniques to extend the life of the battery and consequently the operation life of the device. Most systems incorporate several voltage regulators which supply various subsystems and provide isolation among such subsystems. Low dropout (LDO) voltage regulators are generally used to supply low voltage, low noise analog circuitry. Each LDO regulator demands a large external capacitor, in the range of a few microfarads, to perform. These external capacitors occupy valuable board space, increase the IC pin count, and prohibit system-on-chip (SoC) solutions. The presented research provides a solution to the present bulky external capacitor LDO voltage regulators with a capacitor-less LDO architecture. The large external capacitor was completely removed and replaced with a reasonable 100pF internal output capacitor, allowing for greater power system integration for SoC applications. A new compensation scheme is presented that provides both a fast transient response and full range ac stability from a 0mA to 50mA load current. A 50mA, 2.8V, capacitor-less LDO voltage regulator was fabricated in a TSMC 0.35um CMOS technology, consuming only 65uA of ground current with a dropout voltage of 200mV. Experimental results show that the proposed capacitor-less LDO voltage regulator exceeds the current published works in both transient response and ac stability. The architecture is also less sensitive to process variation and loading conditions. Thus, the presented capacitor-less LDO voltage regulator is suitable for SoC solutions.
Milliken, Robert Jon
Dependence of delivered energy on power conditioner electrical characteristics for utility-interactive PV systems
In a utility-interactive photovoltaic system, the electrical characteristics of the dc-to-ac power-conditioning unit (inverter) influence the quantity of electrical energy delivered by the system, and therefore, affect the user worth of the system. An analysis of the effect of relevant inverter electrical characteristics on the quantity of system-delivered energy is undertaken using computer simulations of system behavior. Significant conclusions are that: (1) the annual system performance advantage of maximum-power-point voltage tracking is small compared with fixed-dc-input voltage operation; (2) low levels of inverter ac-power consumption during times of zero insolation can significantly degrade system performance; (3) the effect of small changes in the array-to-inverter size ratio on the user worth of the system is small; and (4) most of the system energy is delivered at power levels greater than one-half of the nominal array rating, and consequently, the inverter low-power efficiency is less important than is its full-power efficiency. A formula that approximates the inverter annual throughput efficiency with only four laboratory measurements on the inverter is presented.
Rasmussen, N.E.; Branz, H.M.
Voltage spike detection in high field superconducting accelerator magnets
A measurement system for the detection of small magnetic flux changes in superconducting magnets, which are due to either mechanical motion of the conductor or flux jump, has been developed at Fermilab. These flux changes are detected as small amplitude, short duration voltage spikes, which are {approx}15mV in magnitude and lasts for {approx}30 {micro}sec. The detection system combines an analog circuit for the signal conditioning of two coil segments and a fast data acquisition system for digitizing the results, performing threshold detection, and storing the resultant data. The design of the spike detection system along with the modeling results and noise analysis will be presented. Data from tests of high field Nb{sub 3}Sn magnets at currents up to {approx}20KA will also be shown.
Orris, D.F.; Carcagno, R.; Feher, S.; Makulski, A.; Pischalnikov, Y.M.; /Fermilab
Outdoor PV Module Degradation of Current-Voltage Parameters: Preprint
Photovoltaic (PV) module degradation rate analysis quantifies the loss of PV power output over time and is useful for estimating the impact of degradation on the cost of energy. An understanding of the degradation of all current-voltage (I-V) parameters helps to determine the cause of the degradation and also gives useful information for the design of the system. This study reports on data collected from 12 distinct mono- and poly-crystalline modules deployed at the National Renewable Energy Laboratory (NREL) in Golden, Colorado. Most modules investigated showed < 0.5%/year decrease in maximum power due to short-circuit current decline.
Smith, R. M.; Jordan, D. C.; Kurtz, S. R.
Experimental Results from Droop Compensation for the High Voltage Converter Modulators
The High Voltage Convertor Modulators are used to power the RF klystrons used throughout the linear accelerator at the Spallation Neutron Source. The output voltage of the modulator has significant voltage droop and ripple which, combined with low level RF system limitations, affect performance and stability of the accelerator cavities. In conjunction with the progress in the development of the new controller, different modulation techniques were implemented and studied on the test modulator. This paper discusses experimental results from implementation of different modulation schemes has on the modulator output voltage pulse. Thermal measurements were carried out to determine the effect of these modulations schemes on long term reliability of the modulator. Future plans are also discussed.
Patel, Gunjan P [ORNL; Anderson, David E [ORNL; Peplov, Vladimir V [ORNL; Saethre, Robert B [ORNL; Solley, Dennis J [ORNL; Wezensky, Mark W [ORNL
Nominal Exchange Rate Regimes and Relative Price Dispersion: On the Importance of Nominal Exchange Rate Volatility for the Width of the Border �
Based on a broad set of regional aggregated and disaggregated consumer price index (CPI) data from major industrialized countries in Asia, North America and Europe we are examining the role that national borders play for goods market integration. In line with the existing literature we find that intra-national markets are better integrated than international market. Additionally, our results show that there is a large �ocean � effect, i.e., inter-continental markets are significantly more segmented than intra-continental markets. To examine the impact of the establishment of the European Monetary Union (EMU) on integration, we are splitting our sample in a pre-EMU and EMU sample. We find that border effects across EMU countries reduce by about 80 % to 90 % after 1999 whereas border estimates across non-EMU countries have basically not changed. Since globally effective factors have affected all countries in our sample similarly and major integration efforts across EMU countries were made before 1999, we suggest that most of the reduction in EMU border estimates has been �nominal�. Panel unit root evidence shows that the observed large differences in integration across intra- and inter-continental markets remain valid in the longrun. This finding implies that real factors are responsible for the documented segmentations across our sample countries.
Guenter W. Beck
Evaluation of higher distribution and/or utilization voltages. First interim report (December 1978): literature search and problem definition
A literature search has been conducted on the economics and technical problems associated with the use of higher voltages in both the primary distribution and secondary utilization systems. After a literature review and evaluation, an assessment of the state-of-the-art with regard to high voltage has been made and is presented for the primary and secondary distribution systems, end use elements, and economics and system analysis or optimization. An annotated bibliography is provided for each of the three categories. A comprehensive list of potential advantages and disadvantages of higher primary distribution and utilization voltages has also been prepared and is presented.
The call to adopt a nominal set of astrophysical parameters and constants to improve the accuracy of fundamental physical properties of stars
The increasing precision of astronomical observations of stars and stellar systems is gradually getting to a level where the use of slightly different values of the solar mass, radius and luminosity, as well as different values of fundamental physical constants may lead to measurable systematic differences in the determination of basic physical properties. An equivalent issue with an inconsistent value of the speed of light was resolved by adopting a nominal value that is constant and has no error associated with it. Analogously, we suggest that the systematic error in stellar parameters may be avoided if the following two conditions are met: (1) we deprecate the usage of solar quantities Msun, Rsun, and Lsun as units and replace them by the nominal values that are by definition exact and expressed in SI units: 1 MnomSun = 1.988416 x 10^{30} kg, 1 RnomSun = 6.95508 x 10^8 m, and 1 LnomSun = 3.846 x 10^{26} W; and (2) each study containing a determination of fundamental properties of stars or stellar systems s...
Harmanec, Petr
LOW VOLTAGE 14 Mev NEUTRON SOURCE
An apparatus yielding high-energy neutrons at the rate of 10/sup 8/ or more per second by the D,T or D,D reactions is described. The deuterium gas filling is ionized by electrons emitted from a filament, and the resulting ions are focused into a beam and accelerated against a fixed target. The apparatus is built in accordance with the relationship V/sub s/ = A--B log pd, where V/sub s/ is the sparking voltage, p the gas pressure, and d the gap length between the high voltage electrodes. Typical parameters to obtain the high neutron yields are 55 to 80 kv, 0.5 to 7.0 ma beam current, 5 to 12 microns D/sub 2/, and a gap length of 1 centimeter.
Little, R.N. Jr.; Graves, E.R.
Low Swing Dual Threshold Voltage Domino Logic
A low swing domino logic technique is proposed to decrease power consumption without sacrificing noise immunity. With the proposed low swing domino logic circuit technique, active power consumption is reduced by up to 9.4% while improving the noise immunity by 2.6% as compared to standard domino logic circuits. It is also shown that by applying a low swing contention reduction technique, the power savings can be further increased by 6.7% while the delay can be improved by 8.6%. A simple and efficient dual threshold voltage (dual-V t ) circuit technique that incorporates low swing signals is also proposed. It is shown that the proposed dual-V technique reduces the standby leakage current by approximately 235 times while offering enhanced delay characteristics as compared to a standard low threshold voltage implementation.
Volkan Kursun; Eby G. Friedman
Sacramento Area Voltage Support Draft Environmental Impact Statement
The Western Area Power Administration's Central Valley Project transmission system forms an integral part of the interconnected Sacramento area transmission grid. Western is contractually responsible to oversee that the system is operated in accordance with strict reliability standards. Growth in the greater Sacramento, California area and power imported from generation outside the region, have increased the demand on the interconnected electric transmission system, leading to transmission system overloads and reducing the reliability and security of the area power system. Western has prepared this Sacramento Area Voltage Support (SVS) Draft Environmental Impact Statement (EIS) in compliance with Federal laws, regulations and guidelines, principally the ''National Environmental Policy Act'' (NEPA). This Draft EIS evaluates the potential environmental effects of physical improvements to the area's power system. Enhancements are needed to improve system reliability and provide voltage support for the Sacramento area. The results of public scoping meetings, workshops, meetings with agencies, and earlier studies by Western and area utilities helped to develop a range of alternatives for analysis. The Proposed Action involves: Constructing a new double-circuit, 230-kV transmission line paralleling the existing double-circuit, 230-kV line from the O'Banion Substation to the Elverta Substation; Realigning a portion of the existing Cottonwood-Roseville single-circuit, 230-kV transmission line north of Elverta Substation; and Reconductoring the existing double-circuit, 230-kV transmission line from the Elverta Substation to the Tracy Substation. Public Hearings on the Draft EIS will be held between December 9-12, 2002. Comments on this Draft EIS are encouraged and should be sent to Ms. Loreen McMahon (above). Comments must be received by December 30, 2002.
Sacramento Area Voltage Support Final Environmental Impact Statement
The Western Area Power Administration's Central Valley Project transmission system forms an integral part of the interconnected Sacramento area transmission grid. Western is contractually responsible to oversee that the system is operated in accordance with strict reliability standards. Growth in the greater Sacramento, California area and power imported from generation outside the region, have increased the demand on the interconnected electric transmission system, leading to transmission system overloads and reducing the reliability and security of the area power system. Western has prepared this Sacramento Area Voltage Support (SVS) Draft Environmental Impact Statement (EIS) in compliance with Federal laws, regulations and guidelines, principally the National Environmental Policy Act (NEPA). This Draft EIS evaluates the potential environmental effects of physical improvements to the area's power system. Enhancements are needed to improve system reliability and provide voltage support for the Sacramento area. The results of public scoping meetings, workshops, meetings with agencies, and earlier studies by Western and area utilities helped to develop a range of alternatives for analysis. The Proposed Action involves: (1) Constructing a new double-circuit, 230-kV transmission line paralleling the existing double-circuit, 230-kV line from the O'Banion Substation to the Elverta Substation; (2) Realigning a portion of the existing Cottonwood-Roseville single-circuit, 230-kV transmission line north of Elverta Substation; and (3) Reconductoring the existing double-circuit, 230-kV transmission line from the Elverta Substation to the Tracy Substation. Public Hearings on the Draft EIS will be held between December 9-12, 2002. Comments on this Draft EIS are encouraged and should be sent to Ms. Loreen McMahon (above). Comments must be received by December 30, 2002.
A high voltage and current spark gap switch comprising two main electrodes insulatingly supported in opposed spaced relationship and a middle electrode supported medially between the main electrodes and symmetrically about the median line of the main electrodes is described. The middle electrode has a perforation aligned with the median line and an irradiation electrode insulatingly supported in the body of the middle electrode normal to the median line and protruding into the perforation. (AEC)
Dike, R.S.; Lier, D.W.; Schofield, A.E.; Tuck, J.L.
A compact high voltage pulse generator
A compact, easily transportable, pulse generator has been developed for a variety of applications that require a pulse duration in the range of 1 {mu} sec., voltages from 150 to 300 KV and current levels from 2,000 to 3,000 amps. The generator has a simple cylindrical configuration and modular construction to facilitate assembly and service. The generator may be operated single-pulse or repetitively at pulse repetition rates to 50 Hz in a burst mode.
Rohwein, G.J.; Babcock, S.R.
Electro-optic voltage sensor head
The invention is an electro-optic voltage sensor head designed for integration with existing types of high voltage transmission and distribution apparatus. The sensor head contains a transducer, which comprises a transducing material in which the Pockels electro-optic effect is observed. In the practice of the invention at least one beam of electromagnetic radiation is routed into the transducing material of the transducer in the sensor head. The beam undergoes an electro-optic effect in the sensor head when the transducing material is subjected to an E-field. The electro-optic effect is observed as a differential phase a shift, also called differential phase modulation, of the beam components in orthogonal planes of the electromagnetic radiation. In the preferred embodiment the beam is routed through the transducer along an initial axis and then reflected by a retro-reflector back substantially parallel to the initial axis, making a double pass through the transducer for increased measurement sensitivity. The preferred embodiment of the sensor head also includes a polarization state rotator and at least one beam splitter for orienting the beam along major and minor axes and for splitting the beam components into two signals which are independent converse amplitude-modulated signals carrying E-field magnitude and hence voltage information from the sensor head by way of optic fibers.
Crawford, Thomas M. (Idaho Falls, ID); Davidson, James R. (Idaho Falls, ID); Woods, Gregory K. (Cornelius, OR)
The invention is an electro-optic voltage sensor head designed for integration with existing types of high voltage transmission and distribution apparatus. The sensor head contains a transducer, which comprises a transducing material in which the Pockels electro-optic effect is observed. In the practice of the invention at least one beam of electromagnetic radiation is routed into the transducing material of the transducer in the sensor head. The beam undergoes an electro-optic effect in the sensor head when the transducing material is subjected to an E-field. The electro-optic effect is observed as a differential phase a shift, also called differential phase modulation, of the beam components in orthogonal planes of the electromagnetic radiation. In the preferred embodiment the beam is routed through the transducer along an initial axis and then reflected by a retro-reflector back substantially parallel to the initial axis, making a double pass through the transducer for increased measurement sensitivity. The preferred embodiment of the sensor head also includes a polarization state rotator and at least one beam splitter for orienting the beam along major and minor axes and for splitting the beam components into two signals which are independent converse amplitude-modulated signals carrying E-field magnitude and hence voltage information from the sensor head by way of optic fibers. 6 figs.
Crawford, T.M.; Davidson, J.R.; Woods, G.K.
Using Distributed Energy Resources to Supply Reactive Power for Dynamic Voltage Regulation
Abstract Distributed energy (DE) resources are power sources located near load centers and equipped with power electronics converters to interface with the grid, therefore it is feasible for DE to provide reactive power (along with active power) locally for dynamic voltage regulation. In this paper, a synchronous condenser and a DE source with an inverter interface are implemented in parallel in a distribution system to regulate the local voltage. Developed voltage control schemes for the inverter and the synchronous condenser are presented. Experimental results show that both the inverter and the synchronous condenser can regulate the local voltage instantaneously although the dynamic response of the inverter is much faster than the synchronous condenser. In a system with multiple DEs performing local voltage regulation, the interaction of multiple DE at different locations under different load levels may have an impact to the control parameter setting for each individual DE control system. Future research is needed to find out the interaction of DEs to identify the optimal control parameter settings with the consideration of many factors such as system configuration, load variation, and so on
Xu, Yan [ORNL; Li, Fangxing [ORNL; Li, Huijuan [University of Tennessee, Knoxville (UTK); Rizy, D Tom [ORNL; Kueck, John D [ORNL
NIST Online Museum of Quantum Voltage Standards, 1990s
... (Artifact 7, Citation: SP Benz, "Superconductor-normal-superconductor junctions for programmable voltage standards," Appl. Phys. Lett., vol. 67, pp. ...
Activated Sintering, Spark Plasma Sintering and High Voltage ...
Mar 4, 2013 ... Novel Synthesis and Consolidation of Powder Materials : Activated Sintering, Spark Plasma Sintering and High Voltage Electric Discharge�...
Dubal Cell Voltage Drop Initiatives towards Low Energy High ...
About this Abstract. Meeting, 2014 TMS Annual Meeting & Exhibition. Symposium , Aluminum Reduction Technology. Presentation Title, DUBAL CELL VOLTAGE�...
Temperature Fitting Method Predicting Equidistant Voltage Drop of ...
High Temperature Compression Test to Determine the Anode Paste ... Temperature Fitting Method Predicting Equidistant Voltage Drop of Anode Nod in �...
Development of the Platform-Mounted Dynamic Voltage Restorer (PMDVR)
The uninterrupted supply of electrical power is critical for many commercial utility customers with sensitive loads. A voltage sag of a few cycles could cause loss of many thousands of dollars due to lost production from process stoppage and associated clean-up issues. The Platform Mounted Dynamic Voltage Restorer (PMDVR) is a distribution voltage level device that compensates for changes in supply line voltage to maintain acceptable input power to customers.
Distributed Generation Source Stiffness and Its Impact on Voltage Distortion
Distributed generators with loads that create high harmonics can cause excessive voltage distortion. This report's objective was to evaluate under controlled laboratory conditions voltage distortion resulting from application of nonlinear load for three different types of rotary generators and one inverter-based generator. Test results also were used to verify the analytical model for predicting voltage distortion from nonlinear load application.
Selective compensation of voltage harmonics in grid-connected microgrids
1 Selective compensation of voltage harmonics in grid-connected microgrids Mehdi Savaghebia , Juan is proposed for selective compensation of main voltage harmonics in a grid- connected microgrid. The aim level. Keywords Distributed Generator (DG); microgrid; grid-connected; voltage harmonics compensation. 1
Vasquez, Juan Carlos
Secondary Control for Voltage Unbalance Compensation in an Islanded Microgrid
Secondary Control for Voltage Unbalance Compensation in an Islanded Microgrid Mehdi Savaghebi1 microgrid. The aim of the proposed control approach is to enhance the voltage quality at the point of common unbalance. Keywords-distributed generation; microgrid; secondary control; voltage unbalance compensation I
Advanced Integrated Traction System
The United States Department of Energy elaborates the compelling need for a commercialized competitively priced electric traction drive system to proliferate the acceptance of HEVs, PHEVs, and FCVs in the market. The desired end result is a technically and commercially verified integrated ETS (Electric Traction System) product design that can be manufactured and distributed through a broad network of competitive suppliers to all auto manufacturers. The objectives of this FCVT program are to develop advanced technologies for an integrated ETS capable of 55kW peak power for 18 seconds and 30kW of continuous power. Additionally, to accommodate a variety of automotive platforms the ETS design should be scalable to 120kW peak power for 18 seconds and 65kW of continuous power. The ETS (exclusive of the DC/DC Converter) is to cost no more than $660 (55kW at $12/kW) to produce in quantities of 100,000 units per year, should have a total weight less than 46kg, and have a volume less than 16 liters. The cost target for the optional Bi-Directional DC/DC Converter is $375. The goal is to achieve these targets with the use of engine coolant at a nominal temperature of 105C. The system efficiency should exceed 90% at 20% of rated torque over 10% to 100% of maximum speed. The nominal operating system voltage is to be 325V, with consideration for higher voltages. This project investigated a wide range of technologies, including ETS topologies, components, and interconnects. Each technology and its validity for automotive use were verified and then these technologies were integrated into a high temperature ETS design that would support a wide variety of applications (fuel cell, hybrids, electrics, and plug-ins). This ETS met all the DOE 2010 objectives of cost, weight, volume and efficiency, and the specific power and power density 2015 objectives. Additionally a bi-directional converter was developed that provides charging and electric power take-off which is the first step towards enabling a smart-grid application. GM under this work assessed 29 technologies; investigated 36 configurations/types power electronics and electric machines, filed 41 invention disclosures; and ensured technology compatibility with vehicle production. Besides the development of a high temperature ETS the development of industrial suppliers took place because of this project. Suppliers of industrial power electronic components are numerous, but there are few that have traction drive knowledge. This makes it difficult to achieve component reliability, durability, and cost requirements necessary of high volume automotive production. The commercialization of electric traction systems for automotive industry requires a strong diverse supplier base. Developing this supplier base is dependent on a close working relationship between the OEM and supplier so that appropriate component requirements can be developed. GM has worked closely with suppliers to develop components for electric traction systems. Components that have been the focus of this project are power modules, capacitors, heavy copper boards, current sensors, and gate drive and controller chip sets. Working with suppliers, detailed component specifications have been developed. Current, voltage, and operation environment during the vehicle drive cycle were evaluated to develop higher resolution/accurate component specifications.
Greg Smith; Charles Gough
Evaluation of higher distribution and/or utilization voltages. Final report
An electric energy distribution/utilization system cost analysis model is presented for exploring cost tradeoffs (capital investment, operation and maintenance and cost of losses) and optimizing system configuration. The model focuses on the treatment of residential and light commercial service areas with time-varying load characteristics, including customer load profile changes, per customer load growth and service area population growth. Applications of the model are discussed. These include providing insight on: the selection of primary and secondary voltages; conductor sizing; distribution transformer sizing, change out policies and copper-to-core-loss ratio; and limits on allowable voltage variation at the service entrance. Examples are provided to illustrate model capabilities.
Capacitively coupled RF voltage probe having optimized flux linkage
An RF sensor having a novel current sensing probe and a voltage sensing probe to measure voltage and current. The current sensor is disposed in a transmission line to link all of the flux generated by the flowing current in order to obtain an accurate measurement. The voltage sensor is a flat plate which operates as a capacitive plate to sense voltage on a center conductor of the transmission line, in which the measured voltage is obtained across a resistance leg of a R-C differentiator circuit formed by the characteristic impedance of a connecting transmission line and a capacitance of the plate, which is positioned proximal to the center conductor.
Moore, James A. (Powell, TN); Sparks, Dennis O. (Maryville, TN)
A new method and instrument for touch and step voltage measurements
This paper describes a new method and instrument for measuring touch and step voltages near a grounding system, for example in and around a substation. The hardware, software, and testing procedures are an extension of the smart ground multimeter, developed under EPRI sponsorship. The instrument injects a transient electric current between the ground under testing and an auxiliary ground, and it measures ground potential differences (GPDs) at up to six locations. The GPD measurements are processed with software which rejects external noise using correlation methods. Subsequently, statistical estimation methods are used to extract the touch or step voltages from the thousands of measurement points normalized with the system short circuit capability. Knowledge of the short circuit capability of the substation allows the quick measurements of the touch and step voltages.
Meliopoulos, A.P.S. (Georgia Inst. of Technology, Atlanta, GA (United States). School of Electrical and Computer Engineering); Patel, S. (Georgia Power Co., Atlanta, GA (United States)); Cokkinides, G.J. (Univ. of South Carolina, Columbia, SC (United States). Dept. of Electrical and Computer Engineering)
Nobody but You: Sensor Selection for Voltage Regulation in Smart Grid
The increasing availability of distributed energy resources (DERs) and sensors in smart grid, as well as overlaying communication network, provides substantial potential benefits for improving the power system's reliability. In this paper, the problem of sensor selection is studied for the MAC layer design of wireless sensor networks for regulating the voltages in smart grid. The framework of hybrid dynamical system is proposed, using Kalman filter for voltage state estimation and LQR feedback control for voltage adjustment. The approach to obtain the optimal sensor selection sequence is studied. A sub- optimal sequence is obtained by applying the sliding window algorithm. Simulation results show that the proposed sensor selection strategy achieves a 40% performance gain over the baseline algorithm of the round-robin sensor polling.
Mao, Rukun
Miniature UV lamp excited by subnanosecond voltage pulses
Energy, time, and spectral characteristics of emission of the second positive system of N{sub 2} molecules in gaseous nitrogen, Ar - N{sub 2} mixture, and air are investigated. An FPG-10 generator with voltage pulse FWHM of 200 and 400 ps and matched-load amplitudes of 14 and 6 kV, respectively, is used to excite gases. It is shown that excitation can be performed in two regimes using this generator. In the first regime a diffuse discharge is formed at atmospheric pressure, which opens ways to design miniature nanosecond UV lamps. A diffuse discharge is formed due to the generation of runaway electrons, with the aid of electrodes having a small radius of curvature and voltage pulses with a sharp leading edge. In the second regime an elevated average radiation power is obtained under excitation by a barrier discharge. However, the operating pressure is lower in this case, and the sizes of the emitting region and the UV pulse width significantly increase. (laser applications and other topics in quantum electronics)
Erofeev, M V; Baksht, E Kh; Tarasenko, Viktor F; Shut'ko, Yu V [Institute of High Current Electronics, Siberian Branch, Russian Academy of Sciences, Tomsk (Russian Federation)
High Voltage GaN Schottky Rectifiers
Mesa and planar GaN Schottky diode rectifiers with reverse breakdown voltages (V{sub RB}) up to 550V and >2000V, respectively, have been fabricated. The on-state resistance, R{sub ON}, was 6m{Omega}{center_dot} cm{sup 2} and 0.8{Omega}cm{sup 2}, respectively, producing figure-of-merit values for (V{sub RB}){sup 2}/R{sub ON} in the range 5-48 MW{center_dot}cm{sup -2}. At low biases the reverse leakage current was proportional to the size of the rectifying contact perimeter, while at high biases the current was proportional to the area of this contact. These results suggest that at low reverse biases, the leakage is dominated by the surface component, while at higher biases the bulk component dominates. On-state voltages were 3.5V for the 550V diodes and {ge}15 for the 2kV diodes. Reverse recovery times were <0.2{micro}sec for devices switched from a forward current density of {approx}500A{center_dot}cm{sup -2} to a reverse bias of 100V.
Available Transfer Capability Calculation for AC/DC Systems with VSC-HVDC
In this paper, the voltage source converter is equivalently represented by voltage source model, thus the model of voltage source converter--high voltage direct current (VSC-HVDC) system suitable for optimal power flow is established. Each control mode ... Keywords: available transfer capability, voltage source converter, AC/DC systems, sequential quadratic programming method
Guoqing Li; Jian Zhang
The design, construction, and operation of long-distance high-voltage electricity transmission technologies.
This report focuses on transmission lines, which operate at voltages of 115 kV and higher. Currently, the highest voltage lines comprising the North American power grid are at 765 kV. The grid is the network of transmission lines that interconnect most large power plants on the North American continent. One transmission line at this high voltage was built near Chicago as part of the interconnection for three large nuclear power plants southwest of the city. Lines at this voltage also serve markets in New York and New England, also very high demand regions. The large power transfers along the West Coast are generally at 230 or 500 kV. Just as there are practical limits to centralization of power production, there are practical limits to increasing line voltage. As voltage increases, the height of the supporting towers, the size of the insulators, the distance between conductors on a tower, and even the width of the right-of-way (ROW) required increase. These design features safely isolate the electric power, which has an increasing tendency to arc to ground as the voltage (or electrical potential) increases. In addition, very high voltages (345 kV and above) are subject to corona losses. These losses are a result of ionization of the atmosphere, and can amount to several megawatts of wasted power. Furthermore, they are a local nuisance to radio transmission and can produce a noticeable hum. Centralized power production has advantages of economies of scale and special resource availability (for instance, hydro resources), but centralized power requires long-distance transfers of power both to reach customers and to provide interconnections for reliability. Long distances are most economically served at high voltages, which require large-scale equipment and impose a substantial footprint on the corridors through which power passes. The most visible components of the transmission system are the conductors that provide paths for the power and the towers that keep these conductors at a safe distance from each other and from the ground and the natural and built environment. Common elements that are generally less visible (or at least more easily overlooked) include the maintained ROW along the path of the towers, access roads needed for maintenance, and staging areas used for initial construction that may be restored after construction is complete. Also visible but less common elements along the corridor may include switching stations or substations, where lines of similar or different voltages meet to transfer power.
Molburg, J. C.; Kavicky, J. A.; Picel, K. C.
Biased low differential input impedance current receiver/converter device and method for low noise readout from voltage-controlled detectors
A first stage electronic system for receiving charge or current from voltage-controlled sensors or detectors that includes a low input impedance current receiver/converter device (for example, a transimpedance amplifier), which is directly coupled to the sensor output, a source of bias voltage, and the device's power supply (or supplies), which use the biased voltage point as a baseline.
Degtiarenko, Pavel V. (Williamsburg, VA); Popov, Vladimir E. (Newport News, VA)
Continuous flow microwave heating : evaluation of system efficiency and enzyme inactivation kinetics.
??A continuous flow microwave heating system was set up by using one domestic microwave oven (1000W nominal output at 2450MHz). Water was run through the� (more)
Lin, Man Guang, 1966-
On resampling and uncertainty estimation in Linear System Identification
Linear System Identification yields a nominal model parameter, which minimizes a specific criterion based on the single input-output data set. Here we investigate the utility of various methods for estimating the probability distribution of this nominal ... Keywords: Bootstrap, Model validation, Monte Carlo, Resampling, Subsampling, System identification
Simone Garatti; Robert R. Bitmead
Method for improving voltage regulation of batteries, particularly Li/FeS.sub.2 thermal batteries
Batteries are improved, especially with respect to voltage regulation properties, by employing as anode and cathode compositions, those which fall in a thermodynamically invariant region of the metallurgical phase diagram of the combination of the constituent components. The invention is especially useful in the Li/FeS.sub.2 system.
Godshall, Ned A. (Albuquerque, NM)
Method for improving voltage regulation of batteries, particularly Li/FeS/sub 2/ thermal batteries
Batteries are improved, especially with respect to voltage regulation properties, by employing as anode and cathode compositions, those which fall in a thermodynamically invariant region of the metallurgical phase diagram of the combination of the constituent components. The invention is especially useful in the Li/FeS/sub 2/ system.
Godshall, N.A.
Voltage control scheme in distribution network with double feed induction generator wind farm
This paper presents the particle swarm optimization (PSO) for reactive power and voltage control (Volt/Var Control) in distribution system considering DFIG wind farm. In this paper, the reactive power output of DFIG wind farm has been considered as the ... Keywords: DFIG wind turbine, Volt/Var control, distribution network, optimization, particle swarm, wind farm
Jingjing Zhao; Xin Li; Jutao Hao
Incorporating Voltage Fluctuations of the Power Distribution Network into the Transient Analysis of CMOS Logic Gates
Decreased power supply levels have reduced the tolerance to voltage changes within power distribution networks in CMOS integrated circuits. High on-chip currents, required to charge and discharge large on-chip loads while operating at high frequencies, ... Keywords: IR drops, power distribution network, system-on-a-chip
Kevin T. Tang; Eby G. Friedman
Comparison of the Different Circuits Used for Balancing the Voltage of Supercapacitors
1 Comparison of the Different Circuits Used for Balancing the Voltage of Supercapacitors: Studying Performance and Lifetime of Supercapacitors Yasser Diab, Pascal Venet, Gerard Rojat CEGELY UMR-CNRS email@example.com Abstract--The main disadvantage of using supercapacitors in the field of energy storage systems
Solid-state fault current limiter for voltage sag mitigation and its parameters design
Due to the difficulty in electric distribution network reinforcement and the interconnection of more distributed generations, fault current level has become a serious problem in system operations. The utilization of solid-state fault current limiters ... Keywords: power quality, simulation, solid-state fault current limiter, voltage sag
B. Boribun; T. Kulworawanichpong
Common Mode Voltage in case of Transformerless PV Inverters Connected to the Grid
through the parasitic capacitance of the PV panels, can reach very high values. A common-mode model based grid connected PV system with the modeled parasitic capacitances, marked with grey lines, presentCommon Mode Voltage in case of Transformerless PV Inverters Connected to the Grid T. KEREKES* R
Kerekes, Tamas
Technology Assessment and Application Guide for Micro Dynamic Voltage Restorer (DVR)
This report describes and documents the construction, performance, and application of a micro dynamic voltage restorer (DVR). The system is a prototype developed by the researchers at the University of S�o Paulo located in Brazil, South America. The report describes the operation and performance evaluation results of the Micro DVR and issues related to application and installation.
DC-AC Inverters for Static Condenser and Dynamic Voltage Restorer Applications
There has been significant recent interest in general classes of power electronic-based active power conditioners such as static condensers and dynamic voltage restorers. These systems are discussed in this paper with a focus on the inverter output stage. ... Keywords: Power Quality, Static var Compensators, Custom Power
Steven R. Ashcraft; S. Mark Halpin
Design, Development and Testing of a DSP Based Dynamic Voltage Restorer
The paper describes the design, development and testing of a three phase prototype Voltage Source Inverter (VSI) as part of the Superconducting Magnetic Energy Storage (SMES) system technology development at Variable Energy Cyclotron Centre (VECC), Kolkata. ... Keywords: SMES, DSC, LC filter, Injection Transformer, Space Vector PWM, Software PLL
A. De, S. Kumari, V. K. Khare, S. S. Pal, A. Sadhukhan, V. K. Meshram, S. K. Thakur, S. Saha
High voltage design structure for high temperature superconducting device
In accordance with the present invention, modular corona shields are employed in a HTS device to reduce the electric field surrounding the HTS device. In a exemplary embodiment a fault current limiter module in the insulation region of a cryogenic cooling system has at least one fault current limiter set which employs a first corona shield disposed along the top portion of the fault current limiter set and is electrically coupled to the fault current limiter set. A second corona shield is disposed along the bottom portion of the fault current limiter set and is electrically coupled to the fault current limiter set. An insulation barrier is disposed within the insulation region along at least one side of the fault current limiter set. The first corona shield and the second corona shield act together to reduce the electric field surrounding the fault limiter set when voltage is applied to the fault limiter set.
Tekletsadik, Kasegn D. (Rexford, NY)
Social performance as a predictor of peer nominations in newly formed groups: a short-term longitudinal study
We assessed the predictive ability of social performance as measured by the Checklist of Adolescent Problem Situations (CAPS; Cavell & Kelley, 1995) for peer nominations of likability and four behavioral dimensions. The CAPS contains seven scales: Make Friends, Keep Friends, Parents, Siblings, School, work, and Problem Behavior. High scores on these scales are indicative of inadequacy in functioning in that area. Subjects were academically atrisk adolescents who participated in a university-based summer enhancement program. The subjects were previously unacquainted, allowing us to control for the effects of reputation. The CAPS was administered prior to the program and peer nominations were obtained at the end of 8 weeks. Subjects who received higher scores on the Keep Friends and Problem Behavior scales were more likely to receive fewer nominations of friendliness than were subjects whose scores were low on these scales. Social impact scores, determined by nominations of likability, were significantly positively correlated with scores on the Make Friends scale. Rejected adolescents had greater difficulty in work-related situations than either popular or neglected adolescents. The most interesting finding was an interaction effect between sociometric status and gender on the Sibling scale. The clinical and research implications of these findings are discussed.
Kinnee, Chandra Leigh Spencer
Life of Plant Activity Estimates for a Nominal 1000 MWe Pressurized Water Reactor and Boiling Water Reactor
Decommissioning nuclear power plant and disposal site managers must understand the radioactive source term of a nuclear power plant to effectively manage disposition of these materials. This study estimates the radioactive source term from nominal 1000 MWe pressurized water and boiling water reactors to support decisions related to radioactive waste storage, processing, and disposal through decommissioning.BackgroundThis study examines the radionuclide ...
Voltage Pulse Profile Characteristics with Space Charge of a Loaded Pulsed Ionization Chamber
An analytical model describing the voltage pulse profile of a pulsed ionization chamber and its relationship to the electron density in a field drift dominated plasma is formulated. The differential equation derived from the equations of motion and conservation of electron density combined with Poisson's equation for the electric space?charge field in the system is solved analytically for the cylindrical?electrode geometry with an external RC circuit. The numerical analysis for the given initial and boundary conditions yields the anode voltage?signal pulse profiles for the period of electron collection as a function of the initial electron density
S.H. Kim; W.H. Ellis
Planar LTCC transformers for high voltage flyback converters.
This paper discusses the design and use of low-temperature (850 C to 950 C) co-fired ceramic (LTCC) planar magnetic flyback transformers for applications that require conversion of a low voltage to high voltage (> 100V) with significant volumetric constraints. Measured performance and modeling results for multiple designs showed that the LTCC flyback transformer design and construction imposes serious limitations on the achievable coupling and significantly impacts the transformer performance and output voltage. This paper discusses the impact of various design factors that can provide improved performance by increasing transformer coupling and output voltage. The experiments performed on prototype units demonstrated LTCC transformer designs capable of greater than 2 kV output. Finally, the work investigated the effect of the LTCC microstructure on transformer insulation. Although this paper focuses on generating voltages in the kV range, the experimental characterization and discussion presented in this work applies to designs requiring lower voltage.
Schofield, Daryl (NASCENT Technology Inc. , Watertown, SD); Schare, Joshua M.; Glass, Sarah Jill; Roesler, Alexander William; Ewsuk, Kevin Gregory; Slama, George (NASCENT Technology Inc. , Watertown, SD); Abel, Dave (NASCENT Technology Inc. , Watertown, SD)
Barriers to a Wide-Area Trusted Network Early Warning System For Electric
It is apparent that perturbations of the North American electric power grid follow the patterns and characteristics of Self Organized Critical (SOC) systems. Published studies show SOC systems exhibit statistical properties that may result in early warning systems predicting electric power instability and loss of reliability. However, in order for such an early warning system to exist, a trusted wide-area data network must collate information from disparate subsystems and compile that information into homogenous data records for input to a modeling system. This paper explores similarities between widearea trusted computer networks and the needs of a widearea trusted network early warning system for electric power instability. An analysis of commercial equipment used in power stations uncovers disparate access methods and protocols that inhibit interoperability, and yet that problem has been mitigated in computer networking. Recent advances lend hope that wide-area data collection and modeling of electric power system perturbations will be commonplace in the not to distant future. I. Modeling Disturbance Data The electric power grid can be modeled as a complex system of dynamic load and generation balances characterized by two types of stability. Steady-state stability describes the nominal balancing of relatively minor disturbances in load/generation fluctuations caused by normal start-up and shut-down events associated with the millions of appliances and equipment attached to the grid. Constraints on operating parameters � nominally voltage levels, current magnitudes and power flows � are used to achieve steady-state equilibrium where the generation input is matched to system losses and electrical outputs. Whereas, transient stability describes the power systems ability (or lack thereof) to absorb major disturbances and return to a relatively balanced steadystate. Load shedding, generation shedding, and regional
Paul W. Oman; Jeff Roberts
Sequential circuit design for radiation hardened multiple voltage integrated circuits
The present invention includes a radiation hardened sequential circuit, such as a bistable circuit, flip-flop or other suitable design that presents substantial immunity to ionizing radiation while simultaneously maintaining a low operating voltage. In one embodiment, the circuit includes a plurality of logic elements that operate on relatively low voltage, and a master and slave latches each having storage elements that operate on a relatively high voltage.
Clark, Lawrence T. (Phoenix, AZ); McIver, III, John K. (Albuquerque, NM)
Design of Electron Cyclotron Heating and Current Drive System of ITER
Since the end of EDA, the design of the Electron Cyclotron Heating and Current Drive (ECH and CD) system has been modified to respond to progress in physics understanding and change of interface conditions. Nominal RF power of 20 MW is shared by four upper launchers or one equatorial launcher RF beams are steered by front steering mirrors providing wide sweeping angle for the RF beam. DC high voltage power supply may be composed of IGBT pulse step modulators because of high frequency modulation and design flexibility to three different types of 170 GHz gyrotrons provided by three parties. The RF power from the 170 GHz gyrotron is transmitted to the launcher by 63.5 mm{phi} corrugated waveguide line and remotely switched by a waveguide switch between the upper launcher and the equatorial launcher. The ECH and CD system has also a start-up sub-system for assist of initial discharge composed of three 127.5 GHz gyrotrons and a dedicated DC high voltage power supply. Three of transmission lines are shared between 170 GHz gyrotron and 127.5 GHz gyrotron so as to inject RF beam for the start-up through the equatorial launcher. R and Ds of components for high power long pulse and mirror steering mechanism have been on-going in the parties to establish a reliable ITER ECH and CD system.
Kobayashi, N. [ITER, Cadarache (France); Bigelow, T.; Rasmussen, D. [ORNL, Oak Ridge (United States); Bonicelli, T.; Ramponi, G.; Saibene, G. [EFDA, Garching (Germany); Cirant, S. [ENEA-CNR, Milan (Italy); Denisov, G. [IAP, Nizhny Novgorod (Russian Federation); Heidinger, R.; Piosczyk, B. [FZK, Karlsruhe (Germany); Henderson, M.; Hogge, J.-P.; Thumm, M.; Tran, M. Q. [CRPP, Lausanne (Switzerland); Rao, S. L. [IPR, Bhat (India); Sakamoto, K.; Takahashi, K. [JAEA, Naka (Japan); Temkin, R. J. [MIT PSFC, Cambridge (United States); Verhoeven, A. G. A. [FOM IPP, Rijnhuizen (Netherlands); Zohm, H. [MPI IPP, Garching (Germany)
Minimum Energy Compensation Strategy and Characteristic Analysis for Dynamic Voltage Restorer
The minimum energy compensation strategy and its characteristic for Dynamic Voltage Restorer (DVR) considering the equipment�s voltage limitation are discussed. The strategy when the injection voltage is under or especially above the voltage limitation ... Keywords: dynamic voltage restorer, minimum energy compensation, compensation strategy, compensation characteristic, voltage limitation
Yingying Liu; Xu Yonghai; Xiao Xiangning; Guo Chunlin
Research on the SPLL based single phase voltage sag detection technique
The drop of voltage amplitude and the jump of phase angle are two important parameters of the voltage sag. The design of Dynamic Voltage Restorer (DVR) compensation voltage with voltage sag parameters is discussed and a single-phase sag parameter detection ... Keywords: SPLL, detection, single-phase, voltage sag
Xie Yue; Chen Le; Sun Jian; Gong Xu
Triple voltage dc-to-dc converter and method
A circuit and method of providing three dc voltage buses and transforming power between a low voltage dc converter and a high voltage dc converter, by coupling a primary dc power circuit and a secondary dc power circuit through an isolation transformer; providing the gating signals to power semiconductor switches in the primary and secondary circuits to control power flow between the primary and secondary circuits and by controlling a phase shift between the primary voltage and the secondary voltage. The primary dc power circuit and the secondary dc power circuit each further comprising at least two tank capacitances arranged in series as a tank leg, at least two resonant switching devices arranged in series with each other and arranged in parallel with the tank leg, and at least one voltage source arranged in parallel with the tank leg and the resonant switching devices, said resonant switching devices including power semiconductor switches that are operated by gating signals. Additional embodiments having a center-tapped battery on the low voltage side and a plurality of modules on both the low voltage side and the high voltage side are also disclosed for the purpose of reducing ripple current and for reducing the size of the components.
Su, Gui-Jia (Knoxville, TN)
Surge Protection in Low-Voltage AC Power Circuits
Surge Protection in Low-Voltage AC Power Circuits: An 8-part Anthology ... converting old and yellowing papers into 21st Century electronic files, and ...
Multi-winding Homopolar Electric Machine Offers Variable Voltage ...
Wind Energy Industrial Technologies Multi-winding Homopolar Electric Machine Offers Variable Voltage at Low Rotational Speed Oak Ridge National Laboratory. Contact ...
fault diagnosis of a high voltage transmission line using waveform ...
Oct 4, 2013 ... FAULT DIAGNOSIS OF A HIGH VOLTAGE TRANSMISSION LINE USING ... Fault types such as single line to ground, line to line, double line to�...
Medium Voltage Cable Aging Management Guide, Revision 1
Medium-voltage cables (5- to 35-kV rated cables) have provided reasonable service in nuclear power plants. However, there is a concern that cables that have experienced long periods of wet service might degrade and fail in service. Because most plants have had few problems with medium-voltage cable, little on-staff experience with medium-voltage cables exists at most sites. This report has been prepared to provide information that will be of practical use when questions concerning medium-voltage cable lo...
High Voltage Electric Discharge Consolidation of Tantalum Powders
Abstract Scope, The high voltage electric discharge consolidation (HVEDC) is a promising method of the volumetric-porous body manufacturing, which can be�...
The Current-voltage Characteristics of Grain Boundaries in Ionic ...
Presentation Title, The Current-voltage Characteristics of Grain Boundaries in Ionic ... A High-temperature M�ssbauer Study of Iron-doped Ruddlesden-popper �...
(SPS) and High Voltage Electric Discharge Consolidation (HVEDC
Presentation Title, Inter-Particle Contact Phenomena in Spark-Plasma Sintering ( SPS) and High Voltage Electric Discharge Consolidation (HVEDC). Author(s)�...
Spark-plasma Sintering vs. High Voltage Electric Discharge ...
High voltage electric discharge consolidation (HVEDC) includes high axial pressure and discharge of the electrical energy stored in capacitors, thus enabling a�...
Voltage Controlled Creep of a Nanoporous Gold/Electrolyte Hybrid ...
And the creep rate can also be controlled by the voltage (electrochemical ... CNT Reinforced Copper Composite for High Contact Pressure Electrodes by�...
(SPS) and High Voltage Electric Discharge Consolidation (HVEDC)
Presentation Title, Local Heat Balance in Spark-plasma Sintering (SPS) and High Voltage Electric Discharge Consolidation (HVEDC). Author(s), Eugene�...
Road to AC Voltage Standard Leads to Important Junction
Road to AC Voltage Standard Leads to Important Junction. ... Grumman in the mid-1990s.*** A number of innovations since then have led to the first ...
Chronic Benzodiazepine Administration Potentiates High Voltage-Activated Calcium Currents
.aspetjournals.orgDownloadedfrom #12;other drugs of abuse has been reported to enhance high voltage-activated calcium channels (HVAs
Brand, Paul H.
California ISO Real-Time Voltage Security Assessment (VSA) Project...
Arnold Schwarzenegger Governor REAL-TIME GRID RELIABILITY MANAGEMENT California ISO Real-Time Voltage Security Assessment (VSA) Project: Summary of Survey Results on Methodologies...
Patents and Perspective on Surge Protection for Low-Voltage ...
... In a high-voitage inverter the impedance is a resistor functioning to dampen voltage o\\ershoots and to im- plement a relay or solid state second ...
Energy-Big voltage, little package... | ornl.gov
News DOE Pulse Media Contacts Media Mentions RSS Feeds News Home | ORNL | News | Story Tips SHARE Energy-Big voltage, little package Oak Ridge National Laboratory's new Stinger...
A Step Towards Energy-Efficient Voltage Control of Magnetic ...
... By combining these two types of materials, it is possible to create low ... by electric fields (applied voltage) instead of less energy-efficient magnetic ...
Field Guide Updates for 2011: Volume 1 - Compressors for High-Voltage Circuit Breakers, Volume 2 - Lubrication of High-Voltage Circu it Breakers
Preventing Voltage Collapse with Protection Systems that Incorporate
. Weatherford. 1996. Habits of Bald Eagles wintering along the upper John Day River, Oregon. Northwest Science
(2009?) Potential 2nd generation HTSC link to 100 MW hydro Control and quality Industrial load expansion requires high power quality Emergency islanding capability Transmission...
Application of Newton's optimal power flow in voltage/reactive power control
This paper considers an application of Newton's optimal power flow to the solution of the secondary voltage/reactive power control in transmission networks. An efficient computer program based on the latest achievements in the sparse matrix/vector techniques has been developed for this purpose. It is characterized by good robustness, accuracy and speed. A combined objective function appropriate for various system load levels with suitable constraints, for treatment of the power system security and economy is also proposed. For the real-time voltage/reactive power control, a suboptimal power flow procedure has been derived by using the reduced set of control variables. This procedure is based on the sensitivity theory applied to the determination of zones for the secondary voltage/reactive power control and corresponding reduced set of regulating sources, whose reactive outputs represent control variables in the optimal power flow program. As a result, the optimal power flow program output becomes a schedule to be used by operators in the process of the real-time voltage/reactive power control in both normal and emergency operating states.
Bjelogrlic, M.; Babic, B.S. (Electric Power Board of Serbia, Belgrade (YU)); Calovic, M.S. (Dept. of Electrical Engineering, University of Belgrade, Belgrade (YU)); Ristanovic, P. (Institute Nikola Tesla, Belgrade (YU))
Robust Design of Basic Low Voltage CMOS Transconductors
Two new low voltage transconductors are introduced and the statistical design of these transconductors are presented. The circuits operate in the saturation region with fully balanced input signals. Initial circuit simulation results are given. Response surface ... Keywords: design of experiments, low voltage, response surface methodology, roboust design, yield enhancement
Tuna B. Tarim; H. Hakan Kuntman; Mohammed Ismail
Wind Farm Grid Voltage Stability Researching Based on Cascade STATCOM
Though most wind turbine use induction generator, when wind induction generator with power generation, it will produce a series of power quality problems such as voltage fluctuations. This paper discusses the mathematical model of the wind induction ... Keywords: Wind induction generator, Cascade STATCOM, Wind farm, Voltage stability
Li Shengqing, Xu Wenxiang, Li Weizhou, Zeng Huanyue
A Case Study on the Demonstration of Storage for Simultaneous Voltage Smoothing and Peak Shifting
Public Service of New Mexico (PNM) installed an energy storage system for simultaneous voltage smoothing and peak shifting associated with a 500 kW photovoltaic system. The energy storage system is comprised of two elements: a 0.5 MW smoothing battery utilizing UltraBatteries and a 0.25 MW/0.99MWh peak shifting battery using advanced lead acid batteries. The two battery systems, combined with a single 0.75 MW power conditioning system, are co-located with a separately installed 500 kW solar ...
E-beam high voltage switching power supply
A high-power power supply produces a controllable, constant high voltage put under varying and arcing loads. The power supply includes a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules.
Shimer, Daniel W. (Danville, CA); Lange, Arnold C. (Livermore, CA)
A high-power power supply produces a controllable, constant high voltage output under varying and arcing loads. The power supply includes a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules. 5 figs.
Shimer, D.W.; Lange, A.C.
Improving the low voltage ride through of doubly fed induction generator during intermittent voltage source converter faults
on the low voltage ride through (LVRT) capability of the doubly fed induction generator (DFIG) is also) controller to mitigate the effects of these faults is proposed. The DFIG compliance with numerous and compared. Simulation results indicate that these types of faults have a severe impact on the DFIG voltage
Integration and system tests of the Ford/General Electric ac electric drive system
An advanced alternating current electric drive system is being developed by the General Electric Company for Ford Motor Company's ''Advanced Electric Vehicle Powertrain Effort,'' which is a major element of DOE's Single Shaft Electric Propulsion System Program. The integrated transaxle consists of an oil-cooled 50 hp ac induction motor mounted within a 2-speed transaxle. Direct current from the nominal 204 V battery pack is converted to variable frequency, variable voltage 3-phase ac current by a liquid-cooled transistor inverter. A custom-designed inverter motor controller, containing two 8751 microcomputers plus analog and digital circuitry, translates torque commands from the controller to the inverter transistor base drivers that turn on/off power Darlington transistors at appropriate times. After a review of the electric drive system ratings, details of the transistor inverter are presented. Control strategy and controller design are summarized. Electric drive integration and system test results are given.
King, R.D.; Park, J.N.
Measured Performance of California Buydown Program Residential PV Systems
, on average, 62 percent of nominal DC module size. For non-tracking systems, average annual energy production annual energy production per unit of nominal DC module size is approximately 1,100 kWh/year. Both Economic Research, Inc. Sanford Miller, California Energy Commission ABSTRACT More than two thousand small
High voltage dc-dc converter with dynamic voltage regulation and decoupling during load-generated arcs
A high-power power supply produces a controllable, constant high voltage output under varying and arcing loads. The power supply includes a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules.
High voltage dc--dc converter with dynamic voltage regulation and decoupling during load-generated arcs
A high-power power supply produces a controllable, constant high voltage output under varying and arcing loads. The power supply includes a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules. 5 Figs.
Design and code validation of the Jupiter inductive voltage adder (IVA) PRS driver
The proposed Jupiter accelerator is a {approximately} 10-MV, 500-TW system capable of delivering 15-MJ kinetic energy to an imploding plasma radiation source (PRS). The accelerator is based on Hermes-III technology and contains 30 identical inductive voltage adder modules connected in parallel. The modules drive a common circular convolute electrode system in the center of which is located an imploding foil. The relatively high voltage of 8--10 MV is required to compensate for the voltage differential generated across the load due primarily to the fast increase in current (L di/dt) and to lesser extent to the increasing inductance(I dL/dt) and resistive component of the imploding foil. Here we examine the power flow through the device and, in particular, through the voltage adder and long MITL. Analytical models, such as pressure balance and parapotential flow, as well as circuit and PIC codes, were utilized. A new version of the TWOQUICK PIC code, which includes an imploding, cylindrical foil as load, was utilized to compare the power flow calculations done with SCREAMER and TRIFL. The agreement is very satisfactory and adds confidence to the Jupiter design. In addition, an experimental validation of the design is under way this year (FY95) with Hermes III. Long extension MITLs are connected at the end of the voltage adder with inductive and diode loads to benchmark the above design codes. In this paper we outline the accelerator`s conceptual design with emphasis on the power flow and coupling to the inductive load and include preliminary results of Hermes-III experimental design validation.
Mazarakis, M.G.; Poukey, J.W.; Mendel, C.W. [and others
Security�Regions�of� Electrical�Power�Systems�,�Proceedings�Security�Regions�of�Electrical�Power�Systems�by�Power�and�Voltage�Collapse�in� Electrical�Power�Systems�,�IEEE�
Eto, Joseph H.
Induced-charge electrokinetics at large voltages
The classical transport theory cannot explain the experimental behavior of electrochemical systems in the extreme operating conditions required by modern microfluidics devices. Some experimental puzzles include strange ...
Kilic, Mustafa Sabri
Definition: Voltage Stability Monitoring | Open Energy Information
are nearing or exceeding limits.1 Related Terms system References https:www.smartgrid.govcategorytechnologyvoltagestabilitymonitoring C LikeLike UnlikeLike You...
Low-voltage-swing Monolithic DC-DC Conversion
Abstract�A low-voltage-swing MOSFET gate drive technique is proposed in this paper for enhancing the efficiency characteristics of high-frequency-switching dc�dc converters. The parasitic power dissipation of a dc�dc converter is reduced by lowering the voltage swing of the power transistor gate drivers. A comprehensive circuit model of the parasitic impedances of a monolithic buck converter is presented. Closed-form expressions for the total power dissipation of a low-swing buck converter are proposed. The effect of reducing the MOSFET gate voltage swings is explored with the proposed circuit model. A range of design parameters is evaluated, permitting the development of a design space for full integration of active and passive devices of a low-swing buck converter on the same die, for a target CMOS technology. The optimum gate voltage swing of a power MOSFET that maximizes efficiency is lower than a standard full voltage swing. An efficiency of 88 % at a switching frequency of 102 MHz is achieved for a voltage conversion from 1.8 to 0.9 V with a low-swing dc�dc converter based on a 0.18- m CMOS technology. The power dissipation of a low-swing dc�dc converter is reduced by 27.9 % as compared to a standard full-swing dc�dc converter. Index Terms�Buck converter, dc�dc converters, enhanced efficiency, high frequency, low power, low swing, monolithic integration, on-chip voltage conversion, parameter optimization, parasitic impedances, power dissipation modeling, power supply, reduced energy dissipation, reduced voltage swing, switching voltage regulator. I.
Volkan Kursun; Siva G. Narendra; Vivek K. De; Eby G. Friedman
Abstract--This paper investigates how to detect a dynamic voltage collapse situation. The generator and governor dynamics
to an interest in maintaining an optimum, secure and reliable power system operation. One such security issue instability detection and mitigation features to maintain an acceptable level of system reliability power flow model. This analysis has been practically viable because of the view that the voltage
A Survey on the Principle and Control of Dynamic Voltage Restorer
With the development of information and automation techniques, dynamic voltage problems are once again in the spotlight. Dynamic voltage restorer (DVR) is a modern and important custom power device used for mitigating voltage sags in power distribution ... Keywords: voltage sag, dynamic voltage restorer (DVR), control strategy, power quality, optimized compensation, energy storage
Shuhong Kong; Zhongdong Yin; Renzhong Shan; Weidong Shang
On the application of radio frequency voltages to ion traps via helical resonators
Ions confined using a Paul trap require a stable, high voltage and low noise radio frequency (RF) potential. We present a guide for the design and construction of a helical coil resonator for a desired frequency that maximises the quality factor for a set of experimental constraints. We provide an in-depth analysis of the system formed from a shielded helical coil and an ion trap by treating the system as a lumped element model. This allows us to predict the resonant frequency and quality factor in terms of the physical parameters of the resonator and the properties of the ion trap. We also compare theoretical predictions with experimental data for different resonators, and predict the voltage applied to the ion trap as a function of the Q-factor, input power and the properties of the resonant circuit.
Siverns, J D; Weidt, S; Hensinger, W K
Statistics of voltage drop in radial distribution circuits: a dynamic programming approach
We analyze a power distribution line with high penetration of distributed generation and strong variations of power consumption and generation levels. In the presence of uncertainty the statistical description of the system is required to assess the risks of power outages. In order to find the probability of exceeding the constraints for voltage levels we introduce the probability distribution of maximal voltage drop and propose an algorithm for finding this distribution. The algorithm is based on the assumption of random but statistically independent distribution of loads on buses. Linear complexity in the number of buses is achieved through the dynamic programming technique. We illustrate the performance of the algorithm by analyzing a simple 4-bus system with high variations of load levels.
Turitsyn, Konstantin S
J. D. Siverns; L. R. Simkins; S. Weidt; W. K. Hensinger
Design and Optimization of Low Voltage High Performance Dual Threshold CMOS Circuits
Reduction in leakage power has become an important concern in lowvoltage, lowpower and high performance applications. In this paper, we use dual threshold technique to reduce leakage power by assigning high threshold voltage to some transistors in non-critical paths, and using lowthreshold transistors in critical paths. In order to achieve the best leakage power saving under target performance constraints, an algorithm is presented for selecting and assigning an optimal high threshold voltage. A general standby leakage current model which has been veri#ed by HSPICE is used to estimate standby leakage power. Results show that dual threshold technique is good for power reduction during both standby and active modes. The standby leakage power savings for some ISCAS benchmarks can be more than 50#. 1 Introduction With the growing use of portable and wireless electronic systems, reduction in power consumption has become more and more importantintoday's VLSI circuit and system designs #1#, ...
Liqiong Wei; Zhanping Chen; Mark Johnson; Kaushik Roy; Vivek De
EPRI High-Voltage Direct Current (HVDC) Transmission Reference Book: Interim Report
The EPRI High-Voltage Direct Current (HVDC) Transmission Reference Book is a state-of-the-art guidebook that provides transmission companies with a comprehensive, single source of technical information and guidance for designing, building, operating, and extending the life of HVDC transmission systems. The book joins the landmark series of EPRI power delivery reference books. These comprehensive guidebookseach printed with a distinctive colored coverdocument and distill the knowledge and experience of th...
Utility Direct Medium Voltage DC Fast Charger Update: DC Fast Charger Characterization
EPRI developed a fact charging technology for electric vehicles based on a solid state transformer technology known as the Intelligent Universal Transformer (IUT). The IUT technology replaces both the independent power conversion units as well as the conventional transformer with a single interface system which can be used for fast charging of electric vehicles. The versatility of the IUT provides an intermediate DC bus voltage at the 400-V level that can be directly used for a DC distribution ...
Case Study on Conservation Voltage Reduction and Volt-VAR Optimization: Sacramento Municipal Utility District
As part of its SmartSacramento� Project, SMUD tested two control strategies for improving distribution efficiency: conservation voltage reduction (CVR) and volt-VAR optimization (VVO).� SMUD, in conjunction with The Structure Group, enhanced existing control logic and developed new control logic to implement these two control strategies via SMUD�s existing Siemens SCADA system.This case study presents results of a SMUD� pilot in the summer of 2011 to demonstrate the ...
Environmental and Potential Health Effects of High Voltage Direct Current Transmission Lines
High-voltage direct current (HVDC) technology plays an important but highly selective role in the U.S. power delivery system. It is a cost-effective technology for transferring bulk power over long distances, a critical technology for asynchronous grid interconnection, and the preferred technology for long-distance underwater cable transmission. Current interest in renovating the national grid for greater loads and higher reliability as well as unique applications for renewable energy projects, including...
Design & Fabrication of a High-Voltage Photovoltaic Cell
Silicon photovoltaic (PV) cells are alternative energy sources that are important in sustainable power generation. Currently, applications of PV cells are limited by the low output voltage and somewhat low efficiency of such devices. In light of this fact, this project investigates the possibility of fabricating high-voltage PV cells on float-zone silicon wafers having output voltages ranging from 50 V to 2000 V. Three designs with different geometries of diffusion layers were simulated and compared in terms of metal coverage, recombination, built-in potential, and conduction current density. One design was then chosen and optimized to be implemented in the final device design. The results of the simulation serve as a feasibility test for the design concept and provide supportive evidence of the effectiveness of silicon PV cells as high-voltage power supplies.
Felder, Jennifer; /North Carolina State U. /SLAC
Two new low voltage transconductors are introduced and the statistical design of these transconductors are presented. The circuits operate in the saturation region with fully balanced input signals. Initial circuit simulation results are given. Response surface ...