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Selective compensation of voltage harmonics in grid-connected microgrids
E-Print Network (OSTI)
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
Medium Voltage Cable Aging Management Guide, Revision 1
Science Conference Proceedings (OSTI)
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...
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
Utility-Scale Solar Power Converter: Agile Direct Grid Connect Medium Voltage 4.7-13.8 kV Power Converter for PV Applications Utilizing Wide Band Gap Devices
SciTech Connect
Solar ADEPT Project: Satcon is developing a compact, lightweight power conversion device that is capable of taking utility-scale solar power and outputting it directly into the electric utility grid at distribution voltage levels�eliminating the need for large transformers. Transformers �step up� the voltage of the power that is generated by a solar power system so it can be efficiently transported through transmission lines and eventually �stepped down� to usable voltages before it enters homes and businesses. Power companies step up the voltage because less electricity is lost along transmission lines when the voltage is high and current is low. Satcon�s new power conversion devices will eliminate these heavy transformers and connect a utility-scale solar power system directly to the grid. Satcon�s modular devices are designed to ensure reliability�if one device fails it can be bypassed and the system can continue to run.
Electronic circuit for measuring series connected electrochemical cell voltages
DOE Patents (OSTI)
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)
High voltage series connected tandem junction solar battery
A high voltage series connected tandem junction solar battery which comprises a plurality of strips of tandem junction solar cells of hydrogenated amorphous silicon having one optical path and electrically interconnected by a tunnel junction. The layers of hydrogenated amorphous silicon, arranged in a tandem configuration, can have the same bandgap or differing bandgaps. The tandem junction strip solar cells are series connected to produce a solar battery of any desired voltage.
Hanak, Joseph J. (Lawrenceville, NJ)
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
Original article: Selective compensation of voltage harmonics in grid-connected microgrids
In this paper, a novel approach is proposed for selective compensation of main voltage harmonics in a grid-connected microgrid. The aim of compensation is to provide a high voltage quality at the point of common coupling (PCC). PCC voltage quality is ... Keywords: Distributed generator (DG), Grid-connected, Microgrid, Voltage harmonics compensation
Mehdi Savaghebi, Juan C. Vasquez, Alireza Jalilian, Josep M. Guerrero, Tzung-Lin Lee
Analysis of asset health : an approach to monitoring and diagnostics for medium voltage circuit breakers
The Medium Voltage Electric Industry is a very conservative and risk adverse sector that has undergone very little change in the past 30 years when compared to other technologically dependent activities; this reality is ...
Corona, Erick (Erick Gustavo)
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
Power Plant Electrical Reference Series: Guide for Rewinding and Reconditioning Medium Voltage Electric Motors: Volume 17
When medium-voltage motors fail, plant managers and other utility personnel have to oversee repair and rewinding. This guide provides a short-course approach to medium voltage motor repair, with sample specifications and check-off sheets to help the nonspecialist get the best service from the repair shop. The guide can also serve as a technical reference for the specialist.BackgroundThe 16 previous volumes of EPRI's Power Plant Electrical Reference Series ...
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 ...
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
Nano-Composite Dielectrics on Medium-Voltage Model Cables
EPRI early recognized the potential for nanotechnology in power distribution and started a program in 2003 to explore the possibilities of using the technology to enhance the properties of high-voltage (HV) cable dielectrics based on both polyethylene and on ethylene-propylene rubber. This research resulted in encouraging findings, particularly for a formulation based on functionalized silicon dioxide nanoparticles in a cross-linked polyethylene (XLPE) polymer. Following this success, EPRI entered into a...
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
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
GaAs series connected photovoltaic converters for high voltage capacitor charging applications
DOE Green Energy (OSTI)
This report describes the design features of series connected photovoltaic arrays which will be required to charge capacitors to relatively high (400V) voltages in time periods on the order of 1 microsecond. The factors which determine the array voltage and the capacitor charge time are given. Individual element junction designs, along with an interconnect scheme, and a semiconductor process to realize them are presented. Finally, the input laser optical required to meet the requirements is determined.
Rose, B.H.
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)
Plant Engineering: Medium-Voltage Transformer End of Expected Life Guidance
The purpose of this report is to provide guidance to nuclear plant personnel in the determination of the point in life of medium-voltage liquid-immersed and dry-type transformers when long-term planning or contingency planning for the replacement or refurbishment is desirable to preclude end-of-life failure or when preventive maintenance is no longer cost-effective. This report provides recommendations based on historical industry data and subject matter expert (SME) ...
Plant Engineering: Medium-Voltage Cable Failure Mechanism Research, Update 5
This report compiles and extends previously published information gained from EPRI research involving medium-voltage cable failure mechanisms. Four previous reports in this series (EPRI reports 1018777, 1021069, 1022965, and 1024894) presented various results from the study of cables removed from underground applications after 29�38 years of service. The sum knowledge from that work is contained in those four documents, but to view the cumulative information and lessons learned would require ...
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 ...
Plant Support Engineering: Failure Mechanism Assessment of Medium Voltage Ethylene Propylene Rubber Cables
This report presents the results of research that assessed failed ethylene propylene rubber (EPR) medium-voltage (MV) cables to determine the failure mechanism. This information will be used to identify appropriate electrical tests that can be performed on in-service cable. Assessed were a 34-year-old cable manufactured by Okonite with black EPR insulation and a 20-year-old Anaconda Uni-Shieldcable with pink EPR. Both had failed, and both had experienced long-term wetting during service.
Plant Support Engineering: Failure Mechanism Assessment of Medium-Voltage Ethylene Propylene Rubber Cables - Revision 1
This report presents the results of research that assessed failed ethylene propylene rubber (EPR) medium-voltage (MV) cables to determine the failure mechanism. This information will be used to identify appropriate electrical tests that can be performed on in-service cable. Assessed were two 34-year-old cables manufactured by Okonite with black EPR insulation and a 25-year-old Anaconda UniShield cable with pink EPR. All three had failed and had experienced long-term wetting during service. This report is...
Long-Term Operations: Ethylene Propylene Rubber (EPR) Insulation Accelerated Aging Methodology Research for Medium-Voltage Cables
Ethylene propylene rubber�insulated (EPR-insulated) cables are the most common type of medium-voltage cables in U.S. plants. Accelerating the aging of EPR insulations has proven difficult. The research described in this report attempted alternative ways to accelerate the aging of EPR insulation in hopes of achieving a better method. Stresses�such as lower temperature, high-conductivity water, and additional voltage�were used to accelerate aging in a generic EPR cable. Additionally, ...
Mitigation of Voltage and Current Harmonics in Grid-Connected Microgrids Savaghebi, Mehdi; Guerro, Josep M.; Jalilian, Alireza ; Quintero, Juan Carlos Vasquez
Mitigation of Voltage and Current Harmonics in Grid-Connected Microgrids Savaghebi, Mehdi; Guerro-Connected Microgrids. In Proceedings of the 21st IEEE International Symposium on Industrial Electronics (ISIE), 2012;Mitigation of Voltage and Current Harmonics in Grid-Connected Microgrids Mehdi Savaghebi1 , Josep M. Guerrero
Plant Support Engineering: Life Cycle Management Planning Sourcebooks: Medium-Voltage (MV) Cables and Accessories (Terminations and Splices)
EPRI is producing a series of Life Cycle Management Planning Sourcebooks, each containing a compilation of industry experience information and data on aging degradation and historical performance for a specific type of system, structure, or component (SSC). This sourcebook provides information and guidance for implementing cost-effective life cycle management (LCM) planning for medium-voltage (MV) cables and accessories (terminations and field splices)
Connecting Renewables Directly to the Grid: Resilient Multi-Terminal HVDC Networks with High-Voltage High-Frequency Electronics
GENI Project: GE is developing electricity transmission hardware that could connect distributed renewable energy sources, like wind farms, directly to the grid�eliminating the need to feed the energy generated through intermediate power conversion stations before they enter the grid. GE is using the advanced semiconductor material silicon carbide (SiC) to conduct electricity through its transmission hardware because SiC can operate at higher voltage levels than semiconductors made out of other materials. This high-voltage capability is important because electricity must be converted to high-voltage levels before it can be sent along the grid�s network of transmission lines. Power companies do this because less electricity is lost along the lines when the voltage is high.
A Study on Insulation Problems in Drive Fed Medium Voltage Induction Motors.
??The PWM (pulse-width-modulated) type voltage source converters (VSC) allow a precise speed control of induction motors with maximum achievable energy efficiency. However, the rapid growth� (more)
Haq, Saeed UL
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 ...
Considerations for Conversion or Replacement of Medium-Voltage Air-Magnetic Circuit Breakers Using Vacuum or SF6 Technolo gy: Revision to TR-106761
Obsolescence and aging of medium-voltage circuit breakers in nuclear power plants are realities. Plants that are pursuing plant life extension must decide whether to continue to maintain their existing obsolete circuit breakers or to convert or replace them with newer technology. This document provides relevant and useful information regarding conversions and replacement circuit breakers.
Low Wind Speed Technology Phase II: Investigation of the Application of Medium-Voltage Variable-Speed Drive Technology to Improve the Cost of Energy from Low Wind Speed Turbines; Behnke, Erdman and Whitaker Engineering, Inc.
This fact sheet describes a subcontract with Behnke, Erdman & Whitaker Engineering, Inc. to test the feasibility of applying medium-voltage variable-speed drive technology to low wind speed turbines.
NLE Websites -- All DOE Office Websites (Extended Search)
increase production, with help of Northern New Mexico Connect Over the last decade, a string of wineries has come to grace the scenic High Road to Taos. In 2010, Robert Naranjo,...
Utility-Scale Silicon Carbide Semiconductor: Monolithic Silicon Carbide Anode Switched Thyristor for Medium Voltage Power Conversion
ADEPT Project: GeneSiC is developing an advanced silicon-carbide (SiC)-based semiconductor called an anode-switched thyristor. This low-cost, compact SiC semiconductor conducts higher levels of electrical energy with better precision than traditional silicon semiconductors. This efficiency will enable a dramatic reduction in the size, weight, and volume of the power converters and electronic devices it's used in.GeneSiC is developing its SiC-based semiconductor for utility-scale power converters. Traditional silicon semiconductors can't process the high voltages that utility-scale power distribution requires, and they must be stacked in complicated circuits that require bulky insulation and cooling hardware. GeneSiC's semiconductors are well suited for high-power applications like large-scale renewable wind and solar energy installations.
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)
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.
Low Wind Speed Turbine Project Phase II: The Application of Medium-Voltage Electrical Apparatus to the Class of Variable Speed Multi-Megawatt Low Wind Speed Turbines; 15 June 2004--30 April 2005
Kilowatt ratings of modern wind turbines have progressed rapidly from 50 kW to 1,800 kW over the past 25 years, with 3.0- to 7.5-MW turbines expected in the next 5 years. The premise of this study is simple: The rapid growth of wind turbine power ratings and the corresponding growth in turbine electrical generation systems and associated controls are quickly making low-voltage (LV) electrical design approaches cost-ineffective. This report provides design detail and compares the cost of energy (COE) between commercial LV-class wind power machines and emerging medium-voltage (MV)-class multi-megawatt wind technology. The key finding is that a 2.5% reduction in the COE can be achieved by moving from LV to MV systems. This is a conservative estimate, with a 3% to 3.5% reduction believed to be attainable once purchase orders to support a 250-turbine/year production level are placed. This evaluation considers capital costs as well as installation, maintenance, and training requirements for wind turbine maintenance personnel. Subsystems investigated include the generator, pendant cables, variable-speed converter, and padmount transformer with switchgear. Both current-source and voltage-source converter/inverter MV topologies are compared against their low-voltage, voltage-source counterparts at the 3.0-, 5.0-, and 7.5-MW levels.
Erdman, W.; Behnke, M.
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)
Voltage balanced multilevel voltage source converter system
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.
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
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.
Definition: Automated Voltage Regulators | Open Energy Information
Open Energy Info (EERE)
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.
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.
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)
Shield Losses in Medium-Voltage Cables
Utilities can substantially reduce cable costs and circulating current losses by optimizing the design of concentric neutral conductors for underground distribution cables and by configuring installed cables to minimize energy loss. This guide shows how to design neutral conductors for maximum cost-effectiveness and includes calculations of circulating current losses and ampacities for commonly used cables.
Evaluation of Medium-Voltage Cable Joints
This research is a continuation of work evaluating performance of state-of-the-art joints. Three single-phase cold shrink joints and three "I"-type premolded separable connector joints were evaluated. Two of the separable connectors were rated 600 A and one was rated 900 A; both were installed on ethylene propylene rubber (EPR) 15-kV cables.
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
Power quality assessment of specially connected transformers
This paper examines and compares the voltage deviation, voltage unbalance, and harmonic distortion of V-V, Scott, and Le Blanc connected transformers by a novel approach. The power quality factors are needed to truly reflect the loading characteristics ... Keywords: Le Blanc connection, V-V connection, power quality, scott connection
Yao-Hung Chan; Chi-Jui Wu; Shu-Chen Wang
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.
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)
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.
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.
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.
Mitigation of different type voltage sags in low voltage distribution systems using dynamic voltage restorer
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
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)
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
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)
NIST Online Museum of Quantum Voltage Standards, 1970s
... Metrologists wondered if they could connect several junctions in series to make a larger voltage, just as a 12-volt car battery is made up of six 2-volt ...
Method of determining the open circuit voltage of a battery in a closed circuit
The open circuit voltage of a battery which is connected in a closed circuit is determined without breaking the circuit or causing voltage upsets therein. The closed circuit voltage across the battery and the current flowing through it are determined under normal load and then a fractional change is made in the load and the new current and voltage values determined. The open circuit voltage is then calculated, according to known principles, from the two sets of values.
Brown, William E. (Walnut Creek, CA)
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 ...
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
Automated Load Balancing of Medium-Voltage Distribution Circuits
The objective of this project is to investigate the possibility of using an automated system to maintain optimal load balance in distribution circuits. The practice used by many utilities is to use a line crew and engineering personnel to measure load balance at key points in each circuit and manually move single-phase lateral taps to different phases to obtain the desired load balance among the phases. This practice has many shortcomings: The load balance is achieved only for a single point in ...
Cable shield connecting device
A cable shield connecting device for installation on a high voltage cable of the type having a metallic shield, the device including a relatively conformable, looped metal bar for placement around a bared portion of the metallic shield to extend circumferentially around a major portion of the circumference of the metallic shield while being spaced radially therefrom, a plurality of relatively flexible metallic fingers affixed to the bar, projecting from the bar in an axial direction and spaced circumferentially along the bar, each finger being attached to the metallic shield at a portion located remote from the bar to make electrical contact with the metallic shield, and a connecting conductor integral with the bar.
Silva, Frank A. (Basking Ridge, NJ)
Network Connections
Connecting to NERSC Using X Windows Connecting to NERSC with NX Transferring Data Network Performance Queues and Scheduling Job Logs & Analytics Training & Tutorials Software Accounts & Allocations Policies Data Analytics & Visualization Data Management Policies Science Gateways User Surveys NERSC Users Group User Announcements Help Operations for: Passwords & Off-Hours Status 1-800-66-NERSC, option 1 or 510-486-6821 Account Support https://nim.nersc.gov email@example.com 1-800-66-NERSC, option 2 or 510-486-8612 Consulting http://help.nersc.gov firstname.lastname@example.com 1-800-66-NERSC, option 3 or 510-486-8611 Home » For Users » Network Connections Network Connections NERSC's resources can be accessed using SSH and related tools, grid tools, and via the web. This section explains how to connect to NERSC
Substation voltage upgrading
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.)
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�...
Wind farm connection to Serbian distribution network - austere quality requirements vs. more economical power distribution
The paper presents the effects of severe demands on the quality of voltage that is raising the existing Serbian Technical recommendation no. 16. Possibilities of wind farm connection subject to the requirements in terms of voltage change in the transitional ... Keywords: connection, distribution network, energy efficiency, voltage quality, wind farm
Sa�a Mini?; Dragan Tasi?
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.
? 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
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 ...
Delta connected resonant snubber circuit
A delta connected, resonant snubber-based, soft switching, inverter circuit achieves lossless switching during dc-to-ac power conversion and power conditioning with minimum component count and size. Current is supplied to the resonant snubber branches solely by the dc supply voltage through the main inverter switches and the auxiliary switches. Component count and size are reduced by use of a single semiconductor switch in the resonant snubber branches. Component count is also reduced by maximizing the use of stray capacitances of the main switches as parallel resonant capacitors. Resonance charging and discharging of the parallel capacitances allows lossless, zero voltage switching. In one embodiment, circuit component size and count are minimized while achieving lossless, zero voltage switching within a three-phase inverter.
Lai, Jih-Sheng (Knoxville, TN); Peng, Fang Zheng (Oak Ridge, TN); Young, Sr., Robert W. (Oak Ridge, TN); Ott, Jr., George W. (Knoxville, TN)
A delta connected, resonant snubber-based, soft switching, inverter circuit achieves lossless switching during dc-to-ac power conversion and power conditioning with minimum component count and size. Current is supplied to the resonant snubber branches solely by the dc supply voltage through the main inverter switches and the auxiliary switches. Component count and size are reduced by use of a single semiconductor switch in the resonant snubber branches. Component count is also reduced by maximizing the use of stray capacitances of the main switches as parallel resonant capacitors. Resonance charging and discharging of the parallel capacitances allows lossless, zero voltage switching. In one embodiment, circuit component size and count are minimized while achieving lossless, zero voltage switching within a three-phase inverter. 36 figs.
Lai, J.S.; Peng, F.Z.; Young, R.W. Sr.; Ott, G.W. Jr.
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
Easily disassembled electrical connector for high voltage, high frequency connections
An easily accessible electrical connector capable of rapid assembly and disassembly is described wherein a wide metal conductor sheet may be evenly contacted over the entire width of the conductor sheet by opposing surfaces on the connector which provide an even clamping pressure against opposite surfaces of the metal conductor sheet using a single threaded actuating screw. 13 figures.
Milner, J.R.
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.
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)
High voltage electrical amplifier having a short rise time
A circuit, comprising an amplifier and a transformer is disclosed that produces a high power pulse having a fast response time, and that responds to a digital control signal applied through a digital-to-analog converter. The present invention is suitable for driving a component such as an electro-optic modulator with a voltage in the kilovolt range. The circuit is stable at high frequencies and during pulse transients, and its impedance matching circuit matches the load impedance with the output impedance. The preferred embodiment comprises an input stage compatible with high-speed semiconductor components for amplifying the voltage of the input control signal, a buffer for isolating the input stage from the output stage; and a plurality of current amplifiers connected to the buffer. Each current amplifier is connected to a field effect transistor (FET), which switches a high voltage power supply to a transformer which then provides an output terminal for driving a load. The transformer comprises a plurality of transmission lines connected to the FETs and the load. The transformer changes the impedance and the voltage of the output. The preferred embodiment also comprises a low voltage power supply for biasing the FETs at or near an operational voltage. 8 figs.
Christie, D.J.; Dallum, G.E.
A circuit, comprising an amplifier and a transformer is disclosed that produces a high power pulse having a fast response time, and that responds to a digital control signal applied through a digital-to-analog converter. The present invention is suitable for driving a component such as an electro-optic modulator with a voltage in the kilovolt range. The circuit is stable at high frequencies and during pulse transients, and its impedance matching circuit matches the load impedance with the output impedance. The preferred embodiment comprises an input stage compatible with high-speed semiconductor components for amplifying the voltage of the input control signal, a buffer for isolating the input stage from the output stage; and a plurality of current amplifiers connected to the buffer. Each current amplifier is connected to a field effect transistor (FET), which switches a high voltage power supply to a transformer which then provides an output terminal for driving a load. The transformer comprises a plurality of transmission lines connected to the FETs and the load. The transformer changes the impedance and voltage of the output. The preferred embodiment also comprises a low voltage power supply for biasing the FETs at or near an operational voltage.
Christie, David J. (Pleasanton, CA); Dallum, Gregory E. (Livermore, CA)
Offshore Wind Park Connection to an HVDC Platform, without using an AC Collector Platform.
?? This thesis investigates the comparison between two different alternating current topologies of an offshore wind farms connection to an offshore high voltage direct current� (more)
Ahmad, Haseeb
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)
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 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.
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)
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...
TMS320F2812 DSP controller for dynamic voltage restorer (DVR) application for improving of a three phase inverter
This paper discusses a control technique improvement of a three-phase inverter using TMS320F2812 DSP controller for Dynamic Voltage Restorer (DVR) applications. The output of the inverter is then connected to a voltage grid via a second order filter ... Keywords: TMS320F2812 DSP, dynamic voltage restorer (DVR), filter, inverters, total harmonic distortion (THD)
R. Omar; N. A. Rahim
Voltage Stability Analysis of a Distributed Network Incorporating Wind Power Resource
This paper investigates the impacts of a wind farm connected at Harterbeespoort substation in South Africa on voltage stability of the power network. The site wind speed was determined and analyzed for viability. A comparison is made between the use ...
Denis Juma; Bessie Monchusi; Josiah Munda; Adisa Jimoh
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.
A novel control strategy for dynamic voltage restorer using decoupled multiple reference frame PLL (DMRF-PLL)
This paper presents a new control scheme for dynamic voltage restorer (DVR), which consists of a set of series and shunt converters connected back-to-back (BTB), three series transformers, and a dc capacitor installed on the common dc-link. The DVR is ... Keywords: dc capacitor control, decoupled multiple reference frame phase locked loop (DMRF-PLL), dynamic voltage restorer, harmonic and unbalanced voltage compensation, series converters, shunt converters, voltage sag detection
Lin Xu; Yang Han; M. M. Khan; Lidan Zhou; Gang Yao; Chen Chen; Jumin Pan
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
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.
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 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...
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.
Multilevel-Dc-Bus Inverter For Providing Sinusoidal And Pwm Electrical Machine Voltages
A circuit for controlling an ac machine comprises a full bridge network of commutation switches which are connected to supply current for a corresponding voltage phase to the stator windings, a plurality of diodes, each in parallel connection to a respective one of the commutation switches, a plurality of dc source connections providing a multi-level dc bus for the full bridge network of commutation switches to produce sinusoidal voltages or PWM signals, and a controller connected for control of said dc source connections and said full bridge network of commutation switches to output substantially sinusoidal voltages to the stator windings. With the invention, the number of semiconductor switches is reduced to m+3 for a multi-level dc bus having m levels. A method of machine control is also disclosed.
Su, Gui-Jia (Knoxville, TN)
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.
Experiment Hazard Class 13.0 - High Voltage
3.0 - High Voltage 3.0 - High Voltage Applicability This hazard classification applies to all experiments involving the use of High Voltage Equipment. Other hazard classifications and their associated hazard controls may also apply to experiments in this hazard class. The inspection of electric equipment is covered under the APS Policy For User Electric Equipment Inspections. NOTE: Unless required Argonne training has been completed, users are not authorized to perform electrical work. Experiment Category All Hazard Class 13 experiments are categorized as medium risk experiments. Experiment Hazard Control Verification Statements Engineered Controls - Determined by review and results of a DEEI inspection of the equipment. Procedural Controls - Determined by review and results of a DEEI
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
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.
Synthetic laser medium
A laser medium is particularly useful in high average power solid state lasers. The laser medium includes a chromium dopant and preferably neodymium ions as codopant, and is primarily a gadolinium scandium gallium garnet, or an analog thereof. Divalent cations inhibit spiral morphology as large boules from which the laser medium is derived are grown, and a source of ions convertible between a trivalent state and a tetravalent state at a low ionization energy are in the laser medium to reduce an absorption coefficient at about one micron wavelength otherwise caused by the divalent cations. These divalent cations and convertible ions are dispersed in the laser medium. Preferred convertible ions are provided from titanium or cerium sources.
Stokowski, S.E.
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
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
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 ...
APPA Customer Connections Conference
Energy.gov (U.S. Department of Energy (DOE))
The Customer Connections Conference is APPA's annual meeting for utility professionals in the areas of:
E-beam high voltage switching power supply
A high power, solid state power supply is described for producing a controllable, constant high voltage output under varying and arcing loads suitable for powering an electron beam gun or other ion source. The present power supply is most useful for outputs in a range of about 100-400 kW or more. The power supply is comprised of a plurality of discrete switching type dc-dc converter modules, each comprising 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, and an output rectifier for producing a dc voltage at the output of each module. The inputs to the converter modules are fed from a common dc rectifier/filter and are linked together in parallel through decoupling networks to suppress high frequency input interactions. The outputs of the converter modules are linked together in series and connected to the input of the transmission line to the load through a decoupling and line matching network. The dc-dc converter modules are phase activated such that for n modules, each module is activated equally 360.degree./n out of phase with respect to a successive module. The phased activation of the converter modules, combined with the square current waveforms out of the step up transformers, allows the power supply to operate with greatly reduced output capacitance values which minimizes the stored energy available for discharge into an electron beam gun or the like during arcing. The present power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle using simulated voltage feedback signals and voltage feedback loops. Circuitry is also provided for sensing incipient arc currents reflected at the output of the power supply and for simultaneously decoupling the power supply circuitry from the arcing load.
Shimer, Daniel W. (Danville, CA); Lange, Arnold C. (Livermore, CA)
A high power, solid state power supply is described for producing a controllable, constant high voltage output under varying and arcing loads suitable for powering an electron beam gun or other ion source. The present power supply is most useful for outputs in a range of about 100-400 kW or more. The power supply is comprised of a plurality of discrete switching type dc-dc converter modules, each comprising 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, and an output rectifier for producing a dc voltage at the output of each module. The inputs to the converter modules are fed from a common dc rectifier/filter and are linked together in parallel through decoupling networks to suppress high frequency input interactions. The outputs of the converter modules are linked together in series and connected to the input of the transmission line to the load through a decoupling and line matching network. The dc-dc converter modules are phase activated such that for n modules, each module is activated equally 360{degree}/n out of phase with respect to a successive module. The phased activation of the converter modules, combined with the square current waveforms out of the step up transformers, allows the power supply to operate with greatly reduced output capacitance values which minimizes the stored energy available for discharge into an electron beam gun or the like during arcing. The present power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle using simulated voltage feedback signals and voltage feedback loops. Circuitry is also provided for sensing incipient arc currents reflected at the output of the power supply and for simultaneously decoupling the power supply circuitry from the arcing load. 7 figs.
Shimer, D.W.; Lange, A.C.
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
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)
Portec Voltage Regulators: for Emergency Diesel Generators
This report contains information to help utilities address emergency diesel generator voltage regulator issues.
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.
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.
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.
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)
Generalized Region Connection Calculus
The Region Connection Calculus (RCC) is one of the most widely referenced system of high-level (qualitative) spatial reasoning. RCC assumes a continuous representation of space. This contrasts sharply with the fact that spatial information obtained from ... Keywords: (Generalized) Boolean connection algebra, (Generalized) Region Connection Calculus, Continuous space, Discrete space, Mereology, Mereotopology, Qualitative spatial reasoning
Sanjiang Li; Mingsheng Ying
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.
The Neutral Medium
We consider the physical conditions of the neutral medium within, and in the environments of, galaxies. The basic physical and morphological properties of the neutral medium within galaxy disks are now quite well-constrained. Systematic variations in temperature and phase-balance (of cool versus warm neutral gas) are indicated as a function of both radius and z-height. Interestingly, the cool medium line-widths are observed to be dominated by turbulent energy injection within cells of 10 pc to 1 kpc size. Deep new observations reveal that 5-10% of the neutral medium is associated within an extended halo which rotates more slowly and experiences radial inflow. Much of this component is likely to be associated with a ``galactic fountain'' type of phenomenon. However, compelling evidence is also accumulating for the importance of tidal disruption of satellites as well as continuous accretion (of both diffuse and discrete components) in fueling galaxy halos and disks. Continued fueling is even observed on scales of 100's of kpc in galaxy environments, where the neutral component is likely to be merely a trace constituent of a highly ionized plasma.
Robert Braun
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.
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
Liquid chromatographic extraction medium
A method and apparatus for extracting strontium and technetium values from biological, industrial and environmental sample solutions using a chromatographic column is described. An extractant medium for the column is prepared by generating a solution of a diluent containing a Crown ether and dispersing the solution on a resin substrate material. The sample solution is highly acidic and is introduced directed to the chromatographic column and strontium or technetium is eluted using deionized water.
Horwitz, E. Philip (Naperville, IL); Dietz, Mark L. (Evanston, IL)
A method and apparatus are disclosed for extracting strontium and technetium values from biological, industrial and environmental sample solutions using a chromatographic column. An extractant medium for the column is prepared by generating a solution of a diluent containing a Crown ether and dispersing the solution on a resin substrate material. The sample solution is highly acidic and is introduced directed to the chromatographic column and strontium or technetium is eluted using deionized water. 1 fig.
Horwitz, E.P.; Dietz, M.L.
Light-weight DC to very high voltage DC converter
A DC-DC converter capable of generating outputs of 100 KV without a transformer comprises a silicon opening switch (SOS) diode connected to allow a charging current from a capacitor to flow into an inductor. When a specified amount of charge has flowed through the SOS diode, it opens up abruptly; and the consequential collapsing field of the inductor causes a voltage and current reversal that is steered into a load capacitor by an output diode. A switch across the series combination of the capacitor, inductor, and SOS diode closes to periodically reset the SOS diode by inducing a forward-biased current.
Druce, Robert L. (Union City, CA); Kirbie, Hugh C. (Dublin, CA); Newton, Mark A. (Livermore, CA)
A DC-DC converter capable of generating outputs of 100 KV without a transformer comprises a silicon opening switch (SOS) diode connected to allow a charging current from a capacitor to flow into an inductor. When a specified amount of charge has flowed through the SOS diode, it opens up abruptly; and the consequential collapsing field of the inductor causes a voltage and current reversal that is steered into a load capacitor by an output diode. A switch across the series combination of the capacitor, inductor, and SOS diode closes to periodically reset the SOS diode by inducing a forward-biased current. 1 fig.
Druce, R.L.; Kirbie, H.C.; Newton, M.A.
Tech Job Connection Connecting employers and potential
professional, etc. · be seeking a non-Hanford job · be seeking work at a firm within a 50-mile radius of PNNL, such as an executive, manager, engineer, technician, etc. · not primarily be a Hanford contractor · be located within level of growth and profitability. How does the Tech Job Connection work? Employers and individuals
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
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)
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
Energy conversion apparatus for supplying variable voltage direct current power to an electrically propelled vehicle
A synchronous machine, operable as both a motor and a generator, is mounted on an electrically powered vehicle, such as a mine shuttle car, and includes a plurality of conductors having connections that are detachably engagable with receptacles of a stationary power bank. Engagement of the conductors with the receptacles supplies variable voltage alternating current power to the machine. The machine is drivingly connected to a flywheel on the vehicle and, operating as a motor, energizes the flywheel to store a preselected amount of mechanical energy. The electrical connection between the vehicle and the power bank is opened after the flywheel has been sufficiently charged. The stored energy in the flywheel is then available to drive the machine as a generator and produce high frequency, three phase, alternating current power. The generated power is transmitted to a full wave silicon controlled rectifier that converts the alternating current power to direct current for powering the traction motors of the vehicle. A variable voltage controller is connected to the rectifier and actuates the rectifier to supply direct current at a selected voltage level. The controller is responsive to an operator foot pedal. By manually depressing the foot pedal to a selected position, the voltage level of the rectified current is controlled. Thus, the speed of the traction motors is adjustable topropel the vehicle at a speed within a given range. After a portion of the energy stored by the flywheel is consumed, the vehicle is returned to the power bank to replenish the energy supply.
Jamison, W.B.; Burr, J.F.
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
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
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.
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)
Nuclear medium effects in $\
We study the nuclear medium effects in the weak structure functions $F_2(x,Q^2)$ and $F_3(x,Q^2)$ in the deep inelastic neutrino/antineutrino reactions in nuclei. We use a theoretical model for the nuclear spectral functions which incorporates the conventional nuclear effects, such as Fermi motion, binding and nucleon correlations. We also consider the pion and rho meson cloud contributions calculated from a microscopic model for meson-nucleus self-energies. The calculations have been performed using relativistic nuclear spectral functions which include nucleon correlations. Our results are compared with the experimental data of NuTeV and CDHSW.
Haider, H; Athar, M Sajjad; Vacas, M J Vicente
Characterisation of the VELO High Voltage System
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
V-125: Cisco Connected Grid Network Management System Multiple
Energy.gov (U.S. Department of Energy (DOE)) Indexed Site
5: Cisco Connected Grid Network Management System Multiple 5: Cisco Connected Grid Network Management System Multiple Vulnerabilities V-125: Cisco Connected Grid Network Management System Multiple Vulnerabilities April 3, 2013 - 1:44am Addthis PROBLEM: Cisco Connected Grid Network Management System Multiple Vulnerabilities PLATFORM: Cisco Connected Grid Network Management System 2.x ABSTRACT: Some vulnerabilities have been reported in Cisco Connected Grid Network Management System. REFERENCE LINKS: Cisco Security Notice CVE-2013-1163 Cisco Security Notice CVE-2013-1171 Secunia Advisory SA52834 SecurityTracker Alert ID: 1028374 SecurityTracker Alert ID: 1028373 CVE-2013-1163 CVE-2013-1171 IMPACT ASSESSMENT: Medium DISCUSSION: 1) Certain input related to the element list component is not properly sanitised before being returned to the user. This can be exploited to
Fig. 5. The influence of the network cross-traffic on the ability of the SANET to stabilize the generator's voltage
. The bottleneck link, which connects Router 1 and Router 2, has a capacity of 3.0Mbps and is shared by sensor data the generator's voltage under the varying load. The plots show the line voltage and power for two cases power grid [1] SANETs are not sensor networks, not necessarily energy and computation constrained
Liberatore, Vincenzo
Fiber optic current monitor for high-voltage applications
A current monitor which derives its power from the conductor being measured for bidirectionally measuring the magnitude of current (from DC to above 50 khz) flowing through a conductor across which a relatively high level DC voltage is applied, includes a pair of identical transmitter modules connected in opposite polarity to one another in series with the conductor being monitored, for producing from one module a first light signal having an intensity directly proportional to the magnitude of current flowing in one direction through the conductor during one period of time, and from the other module a second light signal having an intensity directly proportional to the magnitude of current flowing in the opposite direction through the conductor during another period of time, and a receiver located in a safe area remote from the high voltage area for receiving the first and second light signals, and converting the same to first and second voltage signals having levels indicative of the magnitude of current being measured at a given time. 6 figs.
Renda, G.F.
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
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
The Physics of the Intergalactic Medium
Intergalactic space is filled with a pervasive medium of ionized gas, the Intergalactic Medium (IGM). A residual neutral fraction is detected in the spectra of Quasi-Stellar Objects at both low and high redshifts, revealing a highly fluctuating medium with temperatures characteristic of photoionized gas. The statistics of the fluctuations are well-reproduced by numerical gravity-hydrodynamics simulations within the context of standard cosmological structure formation scenarios. As such, the study of the IGM offers an opportunity to probe the nature of the primordial density fluctuations on scales unavailable to other methods. The simulations also suggest the IGM is the dominant reservoir of baryons produced by the Big Bang, and so the principal source of the matter from which galaxies formed. The detection of metal systems within the IGM shows that it was enriched by evolved stars early in its history, demonstrating an intimate connection between galaxy formation and the IGM. The author presents a comprehensive review of the current understanding of the structure and physical properties of the IGM and its relation to galaxies, concluding with comments on prospects for furthering the study of the IGM using future ground-based facilities and space-based experiments.
Avery A. Meiksin
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
Bypass apparatus and method for series connected energy storage devices
A bypass apparatus and method for series connected energy storage devices. Each of the energy storage devices coupled to a common series connection has an associated bypass unit connected thereto in parallel. A current bypass unit includes a sensor which is coupled in parallel with an associated energy storage device or cell and senses an energy parameter indicative of an energy state of the cell, such as cell voltage. A bypass switch is coupled in parallel with the energy storage cell and operable between a non-activated state and an activated state. The bypass switch, when in the non-activated state, is substantially non-conductive with respect to current passing through the energy storage cell and, when in the activated state, provides a bypass current path for passing current to the series connection so as to bypass the associated cell. A controller controls activation of the bypass switch in response to the voltage of the cell deviating from a pre-established voltage setpoint. The controller may be included within the bypass unit or be disposed on a control platform external to the bypass unit. The bypass switch may, when activated, establish a permanent or a temporary bypass current path.
Rouillard, Jean (Saint-Luc, CA); Comte, Christophe (Montreal, CA); Daigle, Dominik (St-Hyacinthe, CA)
Public Displays of Connection
Participants in social network sites create self-descriptive profiles that include their links to other members, creating a visible network of connections � the ostensible purpose of these sites is to use this network to make friends, dates, and ...
J. Donath; D. Boyd
Connectibles : tangible social networking
This thesis presents "Connectibles," an instantiation of a tangible social network, a new type of social network application rooted in physical objects and real world social behavior. This research is inspired by social ...
Kalanithi, Jeevan James
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.
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...
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: ...
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.
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�...
Teleparallel Spin Connection
A new expression for the spin connection of teleparallel gravity is proposed, given by minus the contorsion tensor plus a zero connection. The corresponding minimal coupling is covariant under local Lorentz transformation, and equivalent to the minimal coupling prescription of general relativity. With this coupling prescription, therefore, teleparallel gravity turns out to be fully equivalent to general relativity, even in the presence of spinor fields.
V. C. de Andrade; L. C. T. Guillen; J. G. Pereira
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
CMVRTC: Medium Truck Duty Cycle
medium truck duty cycle (MTdc) project medium truck duty cycle (MTdc) project OVERVIEW The Medium Truck Duty Cycle (MTDC) project involves efforts to collect, analyze and archive data related to medium-truck operations in real-world driving environments. Such data and information will be useful to support technology evaluation efforts and to provide a means of accounting for real-world driving performance within medium-class truck analyses. The project involves private industry partners from various truck vocations. The MTDC project is unique in that there currently does not exist a national database of characteristic duty cycles for medium trucks. This project involves the collection of data from multiple vocations (four vocations) and multiple vehicles within these vocations (three vehicles per
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
Interfacing of battery with a medium voltage DC-DC converter using MATLAB/Simulink.
??Electrical power, although convenient form of energy to distribute and use, cannot easily be stored in large quantities economically. Most electrical power generated by utility� (more)
Gebreab, Ermias K.
Circuit Breaker Maintenance: Volume 2: Medium Voltage Circuit Breakers; Part 3: Westinghouse Types DH and DHP
This comprehensive guide will help utilities enhance and optimize maintenance of Westinghouse DH and DHP circuit breakers. It consolidates industry guidelines, applicable standards, original equipment manufacturer recommendations, and hands-on experience relative to these breakers. Optimized maintenance will increase reliability and reduce costs associated with corrective maintenance and equipment downtime.
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).
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.
Double-super-connected digraphs
A strongly connected digraph D is said to be super-connected if every minimum vertex-cut is the out-neighbor or in-neighbor set of a vertex. A strongly connected digraph D is said to be double-super-connected if every minimum vertex-cut is both the out-neighbor ... Keywords: Cartesian product, Double-super-connected, Lexicographic product, Line digraphs, Super-connected
Juan Liu; Jixiang Meng; Zhao Zhang
Method and apparatus for remote tube crevice detection by current and voltage probe resistance measurement
A method and apparatus for determining the extent of contact between an electrically conducting tube and an electrically conductive tubesheet surrounding the tube, based upon the electrical resistance of the tube and tubesheet. A constant current source is applied to the interior of the electrically conducting tube by probes and a voltmeter is connected between other probes to measure the voltage at the point of current injection, which is inversely proportional to the amount of contact between the tube and tubesheet. Namely, the higher the voltage measured by the voltmeter, the less contact between the tube and tubesheet. 4 figs.
Kikta, T.J.; Mitchell, R.D.
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)
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.
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
Instructions for Web VPN Connectivity
Instructions for WebVPN Connectivity October 2010 2 Requirements Web Browser (Internet Explorer, Firefox, Safari, MSN Explorer, etc.) Internet Connection (Preferably Broadband)...
Inert electrode connection
An inert electrode connection is disclosed wherein a layer of inert electrode material is bonded to a layer of conductive material by providing at least one intermediate layer of material therebetween comprising a predetermined ratio of inert material to conductive material. In a preferred embodiment, the connection is formed by placing in a die a layer of powdered inert material, at least one layer of a mixture of powdered inert material and conductive material, and a layer of powdered conductive material. The connection is then formed by pressing the material at 15,000-20,000 psi to form a powder compact and then densifying the powder compact in an inert or reducing atmosphere at a temperature of 1200.degree.-1500.degree. C.
Weyand, John D. (Greensburg, PA); Woods, Robert W. (New Kensington, PA); DeYoung, David H. (Plum Boro, PA); Ray, Siba P. (Plum Boro, PA)
An inert electrode connection is disclosed wherein a layer of inert electrode material is bonded to a layer of conductive material by providing at least one intermediate layer of material therebetween comprising a predetermined ratio of inert material to conductive material. In a preferred embodiment, the connection is formed by placing in a die a layer of powdered inert material, at least one layer of a mixture of powdered inert material and conductive material, and a layer of powdered conductive material. The connection is then formed by pressing the material at 15,000--20,000 psi to form a powder compact and then densifying the powder compact in an inert or reducing atmosphere at a temperature of 1,200--1,500 C. 5 figs.
Weyand, J.D.; Woods, R.W.; DeYoung, D.H.; Ray, S.P.
Connecting to NERSC
Transferring Data Transferring Data Network Performance Queues and Scheduling Job Logs & Analytics Training & Tutorials Software Accounts & Allocations Policies Data Analytics & Visualization Data Management Policies Science Gateways User Surveys NERSC Users Group User Announcements Help Operations for: Passwords & Off-Hours Status 1-800-66-NERSC, option 1 or 510-486-6821 Account Support https://nim.nersc.gov firstname.lastname@example.com 1-800-66-NERSC, option 2 or 510-486-8612 Consulting http://help.nersc.gov firstname.lastname@example.com 1-800-66-NERSC, option 3 or 510-486-8611 Home » For Users » Network Connections » Connecting to NERSC Connecting to NERSC All NERSC computers (except HPSS) are reached using either the Secure Shell (SSH) communication and encryption protocol (version 2) or by Grid tools
?-connections of Description Logics
this paper is to summarize the general transfer results for E- connections that have recently been obtained in [7]. The generality of the results is due to the fact that are defined and investigated using the framework of so-called abstract description systems (ADSs), a common generalization of description logics, modal logics, logics of time and space, and many other logical formalisms [2]. Thus, we can connect not only DLs with DLs, but also, say, description logics with spatial logics [8]. A natural interpretation of link relations in this context would then be, for instance, to describe the spatial extension of abstract (DL) objects
Oliver Kutz; Carsten Lutz; Frank Wolter; Michael Zakharyaschev
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)
Medium Truck Duty Cycle (MTDC)
Routes Data Acquisition System Setup Routes Data Acquisition System Setup Medium Truck Duty Cycle (MTDC) Objective This Department of Energy project focuses on the collection and analysis medium truck (Class-6 and -7) duty cycle data from real-world operations. Analysis of this data will provide information pertaining to the fuel efficiencies and performance of medium trucks in several vocations. Outcomes Rich source of data and information that can contribute to the development of new tools Sound basis upon which DOE can make technology investment decisions A national archive of real-world-based medium-truck operational data that will support medium-duty vehicle energy efficiency research Collected Data Speed & Acceleration Fuel Consumption GPS Location Road Grade
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
Parabolically connected subgroups
All reductive spherical subgroups of the group SL(n) are found for which the intersections with every parabolic subgroup of SL(n) are connected. This condition guarantees that open equivariant embeddings of the corresponding homogeneous spaces into Moishezon spaces are algebraic. Bibliography: 6 titles.
Netai, Igor V [M. V. Lomonosov Moscow State University, Faculty of Mechanics and Mathematics, Moscow (Russian Federation)
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))
Radio-frequency powered glow discharge device and method with high voltage interface
A high voltage accelerating potential, which is supplied by a high voltage direct current power supply, is applied to the electrically conducting interior wall of an RF powered glow discharge cell. The RF power supply desirably is electrically grounded, and the conductor carrying the RF power to the sample held by the probe is desirably shielded completely excepting only the conductor's terminal point of contact with the sample. The high voltage DC accelerating potential is not supplied to the sample. A high voltage capacitance is electrically connected in series between the sample on the one hand and the RF power supply and an impedance matching network on the other hand. The high voltage capacitance isolates the high DC voltage from the RF electronics, while the RF potential is passed across the high voltage capacitance to the plasma. An inductor protects at least the RF power supply, and desirably the impedance matching network as well, from a short that might occur across the high voltage capacitance. The discharge cell and the probe which holds the sample are configured and disposed to prevent the probe's components, which are maintained at ground potential, from bridging between the relatively low vacuum region in communication with the glow discharge maintained within the cell on the one hand, and the relatively high vacuum region surrounding the probe and cell on the other hand. The probe and cell also are configured and disposed to prevent the probe's components from electrically shorting the cell's components. 11 figures.
Duckworth, D.C.; Marcus, R.K.; Donohue, D.L.; Lewis, T.A.
A high voltage accelerating potential, which is supplied by a high voltage direct current power supply, is applied to the electrically conducting interior wall of an RF powered glow discharge cell. The RF power supply desirably is electrically grounded, and the conductor carrying the RF power to the sample held by the probe is desirably shielded completely excepting only the conductor's terminal point of contact with the sample. The high voltage DC accelerating potential is not supplied to the sample. A high voltage capacitance is electrically connected in series between the sample on the one hand and the RF power supply and an impedance matching network on the other hand. The high voltage capacitance isolates the high DC voltage from the RF electronics, while the RF potential is passed across the high voltage capacitance to the plasma. An inductor protects at least the RF power supply, and desirably the impedance matching network as well, from a short that might occur across the high voltage capacitance. The discharge cell and the probe which holds the sample are configured and disposed to prevent the probe's components, which are maintained at ground potential, from bridging between the relatively low vacuum region in communication with the glow discharge maintained within the cell on the one hand, and the relatively high vacuum region surrounding the probe and cell on the other hand. The probe and cell also are configured and disposed to prevent the probe's components from electrically shorting the cell's components.
Duckworth, Douglas C. (Knoxville, TN); Marcus, R. Kenneth (Clemson, SC); Donohue, David L. (Vienna, AT); Lewis, Trousdale A. (Oak Ridge, TN)
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)
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
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.
Property:Nominal Voltage | Open Energy Information
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 +
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 ...
University Connections | .EDUconnections
Office of Scientific and Technical Information (OSTI)
Research on the "Go" with OSTI mobile Research on the "Go" with OSTI mobile Research on the "Go" with OSTI mobile Get the EDUconnections widget and many other great free widgets at Widgetbox! University Spotlight Program The U.S. Department of Energy (DOE) Office of Scientific and Technical Information (OSTI) connects with university research departments and libraries across the nation to increase awareness of DOE's valuable scientific and technical information. OSTI "spotlights" individual universities with connections to DOE scientific research programs. Visit our spotlight below to see examples of universities that are supporting and advancing scientific research and discovery! University Spotlight Visit our Spotlight Archive to learn about great colleges and universities
Flexible swivel connection
A flexible swivel boot connector for connecting a first boot shield section to a second boot shield section, both first and second boot sections having openings therethrough, the second boot section having at least two adjacent accordian folds at the end having the opening, the second boot section being positioned through the opening of the first boot section such that a first of the accordian folds is within the first boot section and a second of the accordian folds is outside of the first boot, includes first and second annular discs, the first disc being positioned within and across the first accordian fold, the second disc being positioned within and across the second accordian fold, such that the first boot section is moveably and rigidly connected between the first and second accordian folds of the second boot section.
Hoh, J.C.
Connections: August 2013
August 2013 August 2013 Community Connections: Our link to Northern New Mexico Communities Latest Issue:Dec. 2013 - Jan. 2014 All Issues » submit IN THIS ISSUE As summer turns to fall, a new school year begins Welcome to the back-to-school issue of Community Connections Celebrating the Lab's 70th Anniversary Activities centered on the week of July 22 Two new exhibits open at the Bradbury Science Museum Nanotechnology and algae biofuels Safeguarding wetland on Laboratory property Protecting our environment For your calendar Talks on science, history, fun with robots and renewable energy resources for small business In other news New Mexico small businesses can submit leveraged proposals beginning August 20 Get updates on LANL Environmental Programs - Click to subscribe Los Alamos wins three R&D 100 awards
Librarian Research Connection Widget
Get the Librarian Research Connection widget and many other great free Get the Librarian Research Connection widget and many other great free widgets at Widgetbox! Access-at one place, all-in-one widget, right at your fingertips-a variety of scientific and technical information sources from the U.S. Department of Energy (DOE) Office of Scientific and Technical Information (OSTI). Help your patron: Included are search capabilities for full-text DOE documents at Information Bridge, DOE resources at Science Accelerator, U.S. government science at Science.gov, and international science at WorldWideScience.org. Spark further scientific discovery by providing your researchers with the scientific and technical information your colleagues are using. Just view the most downloaded documents (monthly) at OSTI or browse the most popular OSTI subject categories and their related documents.
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.
Green Island Power Authority Transmission Voltage Support System...
Green Island Power Authority Transmission Voltage Support System Project Green Island Power Authority Transmission Voltage Support System Project Power point presentation...
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:...
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
Solid-State High-Voltage Crowbar Utilizing Series-Connected Thyristors (A26497)
Proc. Of 17th IEEE International Pulsed Power Conf., Washington, DC (2009)17th IEEE International Pulsed Power Conference Washington District of Columbia, US, 2009999617810
Tooker, J.F.
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.
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.
Hazard-free connection release.
??Fault-tolerant communication in a distributed system requires reliable connection management and message delivery. Reliable connection management includes the guarantee of hazard-free release, in which no� (more)
Walter, Jennifer E.
Connectivity problem in wireless networks
We study the complexity of the following connectivity problem in wireless networks: for a given placement of n nodes in the plane, the goal is to compute a channel and power assignment that forms strongly connected communication structure spanning ...
Dariusz R. Kowalski; Mariusz A. Rokicki
High voltage power supply with modular series resonant inverters
A relatively small and compact high voltage, high current power supply for a laser utilizes a plurality of modules containing series resonant half bridge inverters. A pair of reverse conducting thyristors are incorporated in each series resonant inverter module such that the series resonant inverter modules are sequentially activated in phases 360.degree./n apart, where n=number of modules for n>2. Selective activation of the modules allows precise output control reducing ripple and improving efficiency. Each series resonant half bridge inverter module includes a transformer which has a cooling manifold for actively circulating a coolant such as water, to cool the transformer core as well as selected circuit elements. Conductors connecting and forming various circuit components comprise hollow, electrically conductive tubes such as copper. Coolant circulates through the tubes to remove heat. The conductive tubes act as electrically conductive lines for connecting various components of the power supply. Where it is desired to make electrical isolation breaks, tubes comprised of insulating material such as nylon are used to provide insulation and continue the fluid circuit.
Dreifuerst, Gary R. (Livermore, CA); Merritt, Bernard T. (Livermore, CA)
A relatively small and compact high voltage, high current power supply for a laser utilizes a plurality of modules containing series resonant half bridge inverters. A pair of reverse conducting thyristors are incorporated in each series resonant inverter module such that the series resonant inverter modules are sequentially activated in phases 360{degree}/n apart, where n=number of modules for n>2. Selective activation of the modules allows precise output control reducing ripple and improving efficiency. Each series resonant half bridge inverter module includes a transformer which has a cooling manifold for actively circulating a coolant such as water, to cool the transformer core as well as selected circuit elements. Conductors connecting and forming various circuit components comprise hollow, electrically conductive tubes such as copper. Coolant circulates through the tubes to remove heat. The conductive tubes act as electrically conductive lines for connecting various components of the power supply. Where it is desired to make electrical isolation breaks, tubes comprised of insulating material such as nylon are used to provide insulation and continue the fluid circuit. 11 figs.
Dreifuerst, G.R.; Merritt, B.T.
Medium Modifications of Hadron Properties and Partonic Processes
Chiral symmetry is one of the most fundamental symmetries in QCD. It is closely connected to hadron properties in the nuclear medium via the reduction of the quark condensate , manifesting the partial restoration of chiral symmetry. To better understand this important issue, a number of Jefferson Lab experiments over the past decade have focused on understanding properties of mesons and nucleons in the nuclear medium, often benefiting from the high polarization and luminosity of the CEBAF accelerator. In particular, a novel, accurate, polarization transfer measurement technique revealed for the first time a strong indication that the bound proton electromagnetic form factors in 4He may be modified compared to those in the vacuum. Second, the photoproduction of vector mesons on various nuclei has been measured via their decay to e+e- to study possible in-medium effects on the properties of the rho meson. In this experiment, no significant mass shift and some broadening consistent with expected collisional broadening for the rho meson has been observed, providing tight constraints on model calculations. Finally, processes involving in-medium parton propagation have been studied. The medium modifications of the quark fragmentation functions have been extracted with much higher statistical accuracy than previously possible.
W. K. Brooks, S. Strauch, K. Tsushima
WestConnect Transmission Product
WestConnect Transmission Product Federal Register Notices Customer Notifications Customer Comments Approved Rate Order FERC Confirmation...
Weights and Measures Division Connections
Office of Weights and Measures Connections. Welcome to the Office of Weights and Measures newsletter �Weights and ...
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
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
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
Pota, Himanshu Roy
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.
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
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
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.
Market Manual (Draft rev 5 � �Clean�) Transmission Grid- High Voltage Metering
1.1. The Market Rules allow metering installations to be placed on the high voltage (HV) grid on the supply side of the Defined Meter Point. 1.2. The Market Rules allow metering installations on the high voltage grid to be associated to more than one connection point or embedded connection point. 1.3. The Market Rules permit a metering installation to be registered in respect of more than one facility even though the meter point is not located at the defined meter points, provided that all transfers of energy at any points of supply or consumption for the facilities to which the metering installation relates are determined in a manner satisfactory to the IESO. 1.4. This arrangement permits a reduction in the number of metering installations by using a single HV metering installation to settle multiple connection points or embedded connection points to a single delivery point. This arrangement applies to both energy and transmission settlement. 1.5. Any adjustment between the metering installations and the normal location of the Delivery Point(s) may be by means of an adjustment formula, provided that all
unknown authors
Connections: November 2013
Community Connections: Our link to Northern New Mexico Communities Latest Issue:Dec. 2013 - Jan. 2014 All Issues » submit IN THIS ISSUE Ribbon cutting marks chemistry laboratory upgrades at Northern New Mexico College Los Alamos National Security, LLC provides support Lab transitions employee giving campaigns This year's theme: "I Give Because..." Lab provides environmental support for county construction projects A face-lift for Ashley Pond New gamma-ray observatory begins operations at Sierra Negra volcano in the state of Puebla, Mexico The High-Altitude Water Cherenkov Gamma-Ray Observatory has begun formal operations 20/20 Campaign announces winners Companies recognized for fostering regional growth Lab supports multiethnic science careers Pilot program prepares regional students for national conference
Power converter connection configuration
EMI shielding is provided for power electronics circuits and the like via a direct-mount reference plane support and shielding structure. The thermal support may receive one or more power electronic circuits. The support may aid in removing heat from the circuits through fluid circulating through the support. The support forms a shield from both external EMI/RFI and from interference generated by operation of the power electronic circuits. Features may be provided to permit and enhance connection of the circuitry to external circuitry, such as improved terminal configurations. Modular units may be assembled that may be coupled to electronic circuitry via plug-in arrangements or through interface with a backplane or similar mounting and interconnecting structures.
Beihoff, Bruce C. (Wauwatosa, WI); Kehl, Dennis L. (Milwaukee, WI); Gettelfinger, Lee A. (Brown Deer, WI); Kaishian, Steven C. (Milwaukee, WI); Phillips, Mark G. (Brookfield, WI); Radosevich, Lawrence D. (Muskego, WI)
Connecting Stakeholders, Achieving Green
If Green is gold, why is progress so slow? The public understanding of Green is evolving. Standards are being developed, but there is still much work to be done. Achieving Green is difficult. Necessary conditions include: �A plan that is realistic and sustainable; �Partnership that share the efforts and benefits of Green results; and �A continuous improvement process, i.e. the flexibility to evolve with a dynamic industry and market. A successful Green plan combines vision, initiative, and a willingness to invest in the right tools. To implement a successful plan, leaders have recognized that, in light of the barriers that exist, real progress cannot be made alone. Because of common interest, core stakeholders are natural and necessary allies. As the public acceptance of Green increases, core stakeholders are challenging the status quo. Consequently, stakeholders are not risking inaction, and are connecting to achieve the rewards of being Green.
Rouse, S.; Nolan, B.
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
Original Articles: Universal wind turbine working in grid-connected and island operating modes
In the future power system based on active distribution grid, allowing some portion to be disconnected, the concept of universal wind turbine systems may arise. This concept covers both grid-connected and island operations. This may happen if the voltage ... Keywords: Distributed generation, Droop control, Resynchronization, Wind power
Mario Rizo, Marco Liserre, Emilio Bueno, Francisco J. Rodr�Guez, Francisco Huerta
Enhanced modeling and control of VSIs in microgrids operating in grid-connected mode
This paper focus on the influence of filter dynamics on the performance and stability of current control loops of three-phase, pulse-width modulation (PWM) voltage source inverters (VSIs) in grid-connected operating mode. The analysis considers the application ...
Leonardo Rese; Antonio Simoes Costa; Aguinaldo S. e Silva
SciTech Connect: The SciTech Connect Transition
The SciTech Connect Transition The SciTech Connect Transition The SciTech Connect Transition Now you can visit one site for all the great science information previously searchable in the Energy Citations Database (ECD) and the Information Bridge (IB). ECD will no longer be available beginning August 28, 2013. IB will no longer be available beginning September 18, 2013. SciTech Connect provides access to all the information available via ECD and IB. The basic search at SciTech Connect employs an innovative semantic search capability to help you retrieve more relevant information. You can sign up for an account at SciTech and take advantage of extensive customization features. Don't forget to update your bookmarks! For more details, read OSTI Launches SciTech Connect, Consolidates Information Bridge and Energy Citations Database.
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)
Monolithic series-connected gallium arsenide converter development
We report the development of monolithic GaAs photovoltaic devices intended to convert light generated by a laser or other bright source to electricity. The converters described here can provide higher operating voltage than is possible using a single-junction converter, owing to use of a monolithic circuit that forms a planar series-connected string of single-junction sub-cells. This planar monolithic circuit is arranged to deliver the desired voltage and current during operation at the maximum power point. The paper describes two-, six-, and twelve-junction converters intended for illumination by a laser diode with a wavelength of 0.8 {mu}m. Design and characterization data are presented for optical power in the range of 100 mW to 1 W. The best conversion efficiency exceeds 50%. 9 refs., 4 figs., 2 tabs.
Spitzer, M.B.; McClelland, R.W.; Dingle, B.D.; Dingle, J.E.; Hill, D.S. (Kopin Corp., Taunton, MA (United States)); Rose, B.H. (Sandia National Labs., Albuquerque, NM (United States))
High-voltage technology for the LASL implosion-heating experiment
The implosion-heating power supply uses four 125-kV generators in series. Each generator consists of a fast 125-kV pulse-forming network made up of capacitors attached to a 1m-wide parallel-plate transmission line which is fed through multiple cables from a 2.5- mu F, 0.5- mu H Marx bank charged to 180 kV. To simplify construction it was decided to do without oil or water for high- voltage insulation and grading. The developments described here are: (1) a low- inductance connection between the 125-kV capacitors and the parallel-plate transmission line using an elastomer gasket capable of holding 200 kV; (2) edge flashover prevention by ballooning'' the sheet insulation, by which a 10-cm edge extension of insulation is capable of withstanding a 200-kV pulse for several microseconds; (3) using the edge flashover for over-voltage prevention; (4) grading of voltage along insulators with conducting plastic sheets to prevent flashover at the load switches and cable connections; and (51 capacitively graded insulating supports for the Marx banks. (auth)
Hammel, J.E.; Henins, I.; Marshall, J.; Sherwood, A.R.
How Water Molecules are Connected
Science (Dec. 17, 2004) * *Online subscription needed. How Water Molecules are Connected Water may be the most important molecule on Earth, but our understanding of its properties...
A new current source GTO inverter with sinusoidal output voltage and current
A new current source inverter with sinusoidal output voltage and current is presented. Gate turn-off thyristors (GTO's) and pulsewidth modulation (PWM) control techniques are used in the current source inverter to produce the sinusoidal output voltage and current. Three capacitors are connected to the ac output terminals to absorb overvoltages which occur when the GTO current is cut off and to provide a filter function for reducing harmonics in the output current. Voltage spikes, which have been a serious problem in the practical application of this inverter, are suppressed by adding gate pulses which force the inverter into a state of shoot-through. Moreover, this inverter permits the capacitance of an ac output terminal capacitor for absorbing overvoltages to be reduced to one-tenth or less of that of a commutating capacitor in a conventional thyristor type current source inverter. A 3.7-kW induction motor is driven by the inverter. The motor efficiency and noise level are measured and compared with those obtained when the motor is driven by a conventional voltage source PWM inverter. An operating efficiency five or six percent higher and noise level 10 dB lower are obtained for the former. Therefore, this current source GTO inverter is very suitable for ac motor variable speed drives.
Hombu, M.; Matsuda, Y.; Ueda, A.; Ueda, S.
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: firstname.lastname@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
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.
Electrical system architecture having high voltage bus
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)
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
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.
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.
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, ...
Geodesy and connectivity in lattices
This paper generalizes the notion of symmetrical neighbourhoods, which have been used to define connectivity in the case of sets, to the wider framework of complete lattices having a sup-generating family. Two versions (weak and strong) of the notion ... Keywords: complete, connectivity, geodesy, lattices, mathematical morphology, metrics, neighbourhood, symmetry
Christian Ronse; Jean Serra
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.
SciTech Connect: FAQ
Frequently Asked Questions Frequently Asked Questions Frequently Asked Questions What is SciTech Connect? SciTech Connect is a portal to free, publicly-available DOE-sponsored R&D results including technical reports, bibliographic citations, journal articles, conference papers, books, multimedia and data information. SciTech Connect is a consolidation of two core DOE search engines, the Information Bridge and the Energy Citations Database. SciTech Connect incorporates all of the R&D information from these two products into one search interface. SciTech Connect was developed by the U.S. Department of Energy (DOE) Office of Scientific and Technical Information (OSTI) to increase access to science, technology, and engineering research information from DOE and its predecessor agencies.
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
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.
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 �...
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
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.
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
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.
V-134: Cisco AnyConnect Secure Mobility Client Heap Overflow Lets Local
4: Cisco AnyConnect Secure Mobility Client Heap Overflow Lets 4: Cisco AnyConnect Secure Mobility Client Heap Overflow Lets Local Users Gain Elevated Privileges V-134: Cisco AnyConnect Secure Mobility Client Heap Overflow Lets Local Users Gain Elevated Privileges April 15, 2013 - 1:30am Addthis PROBLEM: Cisco AnyConnect Secure Mobility Client Heap Overflow Lets Local Users Gain Elevated Privileges PLATFORM: Cisco AnyConnect Secure Mobility Client Cisco Secure Desktop ABSTRACT: Some vulnerabilities were reported in Cisco AnyConnect Secure Mobility Client. REFERENCE LINKS: Cisco Security Notice CVE-2013-1172 Cisco Security Notice CVE-2013-1173 SecurityTracker Alert ID: 1028425 CVE-2013-1172 CVE-2013-1173 IMPACT ASSESSMENT: Medium DISCUSSION: A local user can trigger a heap overflow in the Cisco Host Scan component to execute arbitrary code on the target system with System privileges
Method and apparatus for communicating computer data from one point to another over a communications medium
The present invention is directed toward a communications channel comprising a link level protocol, a driver, a receiver, and a canceller/equalizer. The link level protocol provides logic for DC-free signal encoding and recovery as well as supporting many features including CRC error detection and message resend to accommodate infrequent bit errors across the medium. The canceller/equalizer provides equalization for destabilized data signals and also provides simultaneous bi-directional data transfer. The receiver provides bit deskewing by removing synchronization error, or skewing, between data signals. The driver provides impedance controlling by monitoring the characteristics of the communications medium, like voltage or temperature, and providing a matching output impedance in the signal driver so that fewer distortions occur while the data travels across the communications medium.
Arneson, Michael R. (Chippewa Falls, WI); Bowman, Terrance L. (Sumner, WA); Cornett, Frank N. (Chippewa Falls, WI); DeRyckere, John F. (Eau Claire, WI); Hillert, Brian T. (Chippewa Falls, WI); Jenkins, Philip N. (Eau Claire, WI); Ma, Nan (Chippewa Falls, WI); Placek, Joseph M. (Chippewa Falls, WI); Ruesch, Rodney (Eau Claire, WI); Thorson, Gregory M. (Altoona, WI)
Equalizer system and method for series connected energy storing devices
An apparatus and method for regulating the charge voltage of a number of electrochemical cells connected in series is disclosed. Equalization circuitry is provided to control the amount of charge current supplied to individual electrochemical cells included within the series string of electrochemical cells without interrupting the flow of charge current through the series string. The equalization circuitry balances the potential of each of the electrochemical cells to within a pre-determined voltage setpoint tolerance during charging, and, if necessary, prior to initiating charging. Equalization of cell potentials may be effected toward the end of a charge cycle or throughout the charge cycle. Overcharge protection is also provided for each of the electrochemical cells coupled to the series connection. During a discharge mode of operation in accordance with one embodiment, the equalization circuitry is substantially non-conductive with respect to the flow of discharge current from the series string of electrochemical cells. In accordance with another embodiment, equalization of the series string of cells is effected during a discharge cycle.
Rouillard, Jean (Saint-Luc, CA); Comte, Christophe (Montreal, CA); Hagen, Ronald A. (Stillwater, MN); Knudson, Orlin B. (Vadnais Heights, MN); Morin, Andre (Longueuil, CA); Ross, Guy (Beloeil, CA)
Repowering the void : negotiating connectivity
Rejecting the conception of building as island as reflected in American obsession with detached currently reinforced by Zero Energy Building, the thesis explores patterns of connectivity. largely results from insular ...
Lammert, Emily Jane
Consumer Connection | Open Energy Information
Utility Connection | Open Energy Information
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Hestenes' Tetrad and Spin Connections
Defining a spin connection is necessary for formulating Dirac's bispinor equation in a curved space-time. Hestenes has shown that a bispinor field is equivalent to an orthonormal tetrad of vector fields together with a complex scalar field. In this paper, we show that using Hestenes' tetrad for the spin connection in a Riemannian space-time leads to a Yang-Mills formulation of the Dirac Lagrangian in which the bispinor field is mapped to a set of Yang-Mills gauge potentials and a complex scalar field. This result was previously proved for a Minkowski space-time using Fierz identities. As an application we derive several different non-Riemannian spin connections found in the literature directly from an arbitrary linear connection acting on Hestenes' tetrad and scalar fields. We also derive spin connections for which Dirac's bispinor equation is form invariant. Previous work has not considered form invariance of the Dirac equation as a criterion for defining a general spin connection.
Frank Reifler; Randall Morris
Fractal nature of medium-range order in metallic glasses
The atomic structure of metallic glasses has been a long-standing scientific mystery. Unlike crystalline metals, where long-range ordering is established by periodic stacking of fundamental building blocks known as unit cells, a metallic glass has no long-range translational order, although some degrees of short- and medium-range order do exist.1,2,3 Previous studies1,2,3,4 have identified solute-centered clusters, characterized by short-range order (SRO) in favor of unlike bonds, as the fundamental building blocks of metallic glasses. However, how these building blocks are connected or packed to form the medium range order (MRO) remains an open question.1,2,3 Here, based on neutron and x-ray diffraction experiments, we propose a new packing scheme - the self-similar packing of atomic clusters. We show that MRO has the characteristics of a fractal network with a dimension of 2.38, and is described by a power-law correlation function over the medium-range length scale. Our finding provides a new prospective of order in disordered materials and has broad implications for understanding the structure-property relationship in metallic glasses, particularly those involving change in length scales due to phase transformation and mechanical deformation.
Ma, Dong [ORNL; Stoica, Alexandru Dan [ORNL; Wang, Xun-Li [ORNL
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)
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.
High-temperature superconducting (HTS) power devices operating in liquid nitrogen frequently require high-voltage bushings to carry the current leads from the superconducting windings to the room temperature grid connections. Oak Ridge National Laboratory is collaborating with Waukesha Electric Systems, SuperPower, and Southern California Edison to develop and demonstrate an HTS utility power transformer. Previous dielectric high voltage tests in support of this program have been carried out in test cryostats with commercial epoxy resin bushings from Electro Composites Inc. (ECI). Though the bushings performed well in these short-term tests, their long-term operation at high voltage in liquid nitrogen needs to be verified for use on the utility grid. Long-term tests are being carried out on a sample 28-kV-class ECI bushing. The bushing has a monolithic cast, cycloaliphatic resin body and is fire- and shatter-resistant. The test cryostat is located in an interlocked cage and is energized at 25 kVac around the clock. Liquid nitrogen (LN) is automatically refilled every 9.5 hours. Partial discharge, capacitance, and leakage resistance tests are periodically performed to check for deviations from factory values. At present, over 2400 hours have been accumulated with no changes in these parameters. The tests are scheduled to run for four to six months.
Schwenterly, S W [ORNL; Pleva, Ed [Waukesha Electric Systems, Waukesha, WI; Ha, Tam T [ORNL
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
Connecting the Molecular and the Continuum Scales
Connecting the Molecular and the Continuum Scales Connecting the Molecular and the Continuum Scales Key Challenges: A molecular-scale understanding of structure and surface...
Connect with ORNL | ornl.gov
For Academia For Industry Science Saturdays attract hundreds of students Secretary Moniz gets a 3-D view of a simulated reactor core Home | Connect with ORNL SHARE Connect...
GROWDERS Demonstration of Grid Connected Electricity Systems...
GROWDERS Demonstration of Grid Connected Electricity Systems (Smart Grid Project) Jump to: navigation, search Project Name GROWDERS Demonstration of Grid Connected Electricity...
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
Medium-induced multi-photon radiation
We study the spectrum of multi-photon radiation off a fast quark in medium in the BDMPS/ASW approach. We reproduce the medium-induced one-photon radiation spectrum in dipole approximation, and go on to calculate the two-photon radiation in the Moli\\`{e}re limit. We find that in this limit the LPM effect holds for medium-induced two-photon ladder emission.
Ma, Hao; Tywoniuk, Konrad
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)
ENERGY STAR Resources for Small & Medium Manufactures
Small & Medium Manufacturers Guide to Energy Management June 2013 ENERGY STAR is a U.S. Environmental Protection Agency Program helping organizations and individuals fight climate...
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...
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)
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.
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 ...
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...
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.
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�...
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...
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...
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 ...
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.
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 ...
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 ...
Electronic circuit for measuring series connected ...
An electronic circuit for measuring voltage signals in an energy storage device is disclosed. The electronic circuit includes a plurality of energy storage cells ...
Plant Engineering: Results of Cable Rejuvenation of Severely Degraded Black Ethylene Propylene Rubber Medium-Voltage Cables
This report describes the evaluation of the effects of commercially available rejuvenation on black ethylene propylene rubber (EPR) insulation. Black EPR is one of the main insulation types used in power plants built in the late 1960s to mid-1970s. Diagnostic testing and failure mechanism research performed by the Electric Power Research Institute (EPRI) have shown that this insulation, when exposed to wet or submerged conditions, can degrade to the point at which reliability concerns would require ...
Evaluation of Medium-Voltage Cable Joints: Single-Phase, Three-Phase, and Branch Transition Joints
This report evaluates three single-phase transition joints, three three-phase trifurcating transition joints, and one three-phase trifurcating transition branch joint between ethylene propylene rubber (EPR) and paper-insulated lead-covered (PILC) 15-kV cables. Among installation parameters evaluated are time to install, complexity, skill required, ease of assembly, margin for error, and space needed for joint assembly and fabrication.
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...
The medium is the medium : the convergence of video, art and television at WGBH (1969)
On March 23rd 1969 Boston's public television station WGBH broadcast a program titled The Medium is the Medium. The program was a half-hour long compilation of short videos by six artists. The six pieces ranged from ...
Nadeau, James A. (James Andrew)
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
Medium energy nuclear data for applications
The types of medium energy nuclear data required for applications are discussed. Features of analysis tools, consisting of both detailed nuclear model codes and simple formulas based on nuclear systematics are presented. The activities of the Medium Energy Nuclear Data Working Group (MENDWG) are described including the recent benchmark comparison of nuclear model codes. 40 refs., 7 figs.
Pearlstein, S.
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
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.
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
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.
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
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
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 ...
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.
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.
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 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
Connected gradings and fundamental group.
The main purpose of this paper is to provide explicit computations of the fundamental group of several algebras. For this purpose, given a $k$-algebra $A$, we consider the category of all connected gradings of $A$ by a group $G$ and we study the relation between gradings and Galois coverings. This theoretical tool gives information about the fundamental group of $A$, which allows its computation using complete lists of gradings.
Claude Cibils (I3M); Maria Julia Redondo (Departamento De Matematica UNS); Andrea Solotar (Departamento De Matematica UBA)
Wireless Connectivity for Electric Substations
The information age has seen the advent of low-cost, reliable wireless networking technologies, originally developed for information technology (IT) applications. Control system and IT vendors and equipment are converging at a rapid rate. Today there is a plethora of wireless connectivity solutions for various control system components. As always, the goal of a control system security process is to balance security while operating the control system within resource limits. This report identifies and eval...
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
Connections for solid oxide fuel cells
A connection for fuel cell assemblies is disclosed. The connection includes compliant members connected to individual fuel cells and a rigid member connected to the compliant members. Adjacent bundles or modules of fuel cells are connected together by mechanically joining their rigid members. The compliant/rigid connection permits construction of generator fuel cell stacks from basic modular groups of cells of any desired size. The connections can be made prior to installation of the fuel cells in a generator, thereby eliminating the need for in-situ completion of the connections. In addition to allowing pre-fabrication, the compliant/rigid connections also simplify removal and replacement of sections of a generator fuel cell stack.
Collie, Jeffrey C. (Pittsburgh, PA)
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.
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
Small- and Medium-Sized Reactors
to essentially the same concept. As defined by the IAEA, a small reactor has an output electrical power of 300 MWe or less while a medium-sized reactor has an electrical power...
Special light trajectories in optical medium
The Fermat principle is used to define trajectories in nonhomogenous optical media. The Poincare model of the Lobachevskii geometry is derived. The index of refraction is determined for the light confined in the circular trajectory in the optical medium.
Miroslav Pardy
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
SciTech Connect: higgs
higgs Find higgs Find How should I search Scitech Connect ... Basic or Advanced? Basic Search Advanced × Advanced Search Options Full Text: Bibliographic Data: Creator / Author: Name Name ORCID Title: Subject: Identifier Numbers: Research Org.: Sponsoring Org.: Site: All Alaska Power Administration, Juneau, Alaska (United States) Albany Research Center (ARC), Albany, OR (United States) Albuquerque Complex - NNSA Albuquerque Operations Office, Albuquerque, NM (United States) Amarillo National Resource Center for Plutonium, Amarillo, TX (United States) Ames Laboratory (AMES), Ames, IA (United States) Argonne National Laboratory (ANL), Argonne, IL (United States) Argonne National Laboratory-Advanced Photon Source (United States) Atlanta Regional Office, Atlanta, GA (United States) Atmospheric Radiation Measurement (ARM)
SciTech Connect: auroras
auroras Find auroras Find How should I search Scitech Connect ... Basic or Advanced? Basic Search Advanced × Advanced Search Options Full Text: Bibliographic Data: Creator / Author: Name Name ORCID Title: Subject: Identifier Numbers: Research Org.: Sponsoring Org.: Site: All Alaska Power Administration, Juneau, Alaska (United States) Albany Research Center (ARC), Albany, OR (United States) Albuquerque Complex - NNSA Albuquerque Operations Office, Albuquerque, NM (United States) Amarillo National Resource Center for Plutonium, Amarillo, TX (United States) Ames Laboratory (AMES), Ames, IA (United States) Argonne National Laboratory (ANL), Argonne, IL (United States) Argonne National Laboratory-Advanced Photon Source (United States) Atlanta Regional Office, Atlanta, GA (United States) Atmospheric Radiation Measurement (ARM)
SciTech Connect: plasma
plasma Find plasma Find How should I search Scitech Connect ... Basic or Advanced? Basic Search Advanced × Advanced Search Options Full Text: Bibliographic Data: Creator / Author: Name Name ORCID Title: Subject: Identifier Numbers: Research Org.: Sponsoring Org.: Site: All Alaska Power Administration, Juneau, Alaska (United States) Albany Research Center (ARC), Albany, OR (United States) Albuquerque Complex - NNSA Albuquerque Operations Office, Albuquerque, NM (United States) Amarillo National Resource Center for Plutonium, Amarillo, TX (United States) Ames Laboratory (AMES), Ames, IA (United States) Argonne National Laboratory (ANL), Argonne, IL (United States) Argonne National Laboratory-Advanced Photon Source (United States) Atlanta Regional Office, Atlanta, GA (United States) Atmospheric Radiation Measurement (ARM)
Climate Change and Wildfires: What's the Connection?
Climate Change and Wildfires: What's the Connection? Print E-mail What is the connection between climate change and wildfires Thursday, August 22, 2013 Featured by EPA, a member of...
Quick-connect coupler for remote manipulation
An adaptor for a single-point attachment, push-to-connect/pull-to- disconnect, quick-connect fluid coupler which enables the coupler to be remotely manipulated. 5 figs.
Dobbins, J.C.
SciTech Connect: "smart grid"
Conference: Optical Observations of Gamma-Ray Bursts: Connections to GeVTeV Jets Citation Details In-Document Search Title: Optical Observations of Gamma-Ray Bursts: Connections...
Implementation for simplifying Bluetooth device connection methods
This thesis provides a way for users to easily add and remove devices to secure groups, allowing for a more intuitive way of making connections between devices. These groups allow users to seamlessly make connections between ...
Wan, Tehyih Debbie, 1981-
EPAct and Clean Cities: What's the Connection?
Fact sheet describes the connection between EPAct and Clean Cities and describes the basics of each program.
Not Available
Conservation laws for a general Lorentz connection
We derive conservation laws for energy-momentum (canonical and dynamical) and angular momentum for a general Lorentz connection.
Poplawski, Nikodem J
UConnect Wireless Connection Windows 7 Configuration
UConnect Wireless Connection Windows 7 Configuration page 1 revised February, 2012 Configuring a UConnect Wireless Connection on Windows 7 1. Open the Network and Sharing Center a. Click the Windows icon screen, select Network and Sharing Center. #12;UConnect Wireless Connection Windows 7 Configuration page
Provancher, William
Ethanol production using a soy hydrolysate-based medium or a yeast autolysate-based medium
This invention presents a method for the production of ethanol that utilizes a soy hydrolysate-based nutrient medium or a yeast autolysate-based medium nutrient medium in conjunction with ethanologenic bacteria and a fermentable sugar for the cost-effective production of ethanol from lignocellulosic biomass. The invention offers several advantages over presently available media for use in ethanol production, including consistent quality, lack of toxins and wide availability.
Ingram, Lonnie O. (Gainesville, FL)
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
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 ...
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, ...
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 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.
Quartz crystal microbalance based on passive frequency to voltage converter
In dynamics of evaporation or drying of microdrops from a solid surface, a faster and precise quartz crystal microbalance (QCM) is needed. The fast QCM based on frequency to voltage converter is an attractive and powerful tool in the investigation of the dynamic regime of evaporation to translate the frequency shift in terms of a continuous voltage change. The frequency shift monitoring in fast QCM applications is a real challenge for electronic processing interface. Originally developed as a frequency shift processing interface, this novel passive frequency to voltage converter can produce faster, stable, and accurate results in regard to the QCM sensor behavior. In this article, the concept and circuit of passive frequency to voltage converter will be explained followed by static and dynamic characterization. Experimental results of microdrops evaporation will be given.
Burda, Ioan; Tunyagi, Arthur [Department of Physics, Babes-Bolyai University, Cluj-Napoca, 400084 (Romania)
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
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)
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-
Functionalized High Voltage Spinel Composite for High Power ...
Recently, spinel LiNi0.5Mn1.5O4 with high working voltage and long cycle life makes it become the one of most promising cathode for high power delivery.
ESS 2012 Peer Review - Low Cost, Manufacturable High Voltage...
Storage for Power Flow Management and Voltage Control on an 11kV UK Distribution Network", 20th International Conference on Electricity Distribution, June 2009. S1 S2 C1 C2...
Light Flicker in Compact Fluorescent Lamps Caused by Voltage Fluctuations
This power quality (PQ) case study presents tests performed at the EPRI Power Electronics Applications Center (PEAC) Power Quality Test Facility to characterize the light output of an incandescent lamp and compact fluorescent lamps during voltage fluctuations.
Chloromethyl chlorosulfate as a voltage delay inhibitor in lithium cells
Chloromethyl chlorosulfate (CMCS) is used as a passive film growth inhibitor in electrochemical cells to minimize voltage delay and low-voltage discharge. Film growth on lithium anodes is significantly diminished when CMCS is added to SOCl.sub.2 and SO.sub.2 Cl.sub.2 electrolytes of lithium batteries. The CMCS also has the effect of extending the shelf-life of Li/SOCl.sub.2 and Li/SO.sub.2 Cl.sub.2 batteries.
Delnick, Frank M. (Albuquerque, NM)
Chloromethyl chlorosulfate (CMCS) is used as a passive film growth inhibitor in electrochemical cells to minimize voltage delay and low-voltage discharge. Film growth on lithium anodes is significantly diminished when CMCS is added to SOCl[sub 2] and SO[sub 2]Cl[sub 2] electrolytes of lithium batteries. The CMCS also has the effect of extending the shelf-life of Li/SOCl[sub 2] and Li/SO[sub 2]Cl[sub 2] batteries.
Delnick, F.M.
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...
Measuring Helical FCG Voltage with an Electric Field Antenna
A method of measuring the voltage produced by a helical explosive flux compression generator using a remote electric field antenna is described in detail. The diagnostic has been successfully implemented on several experiments. Measured data from the diagnostic compare favorably with voltages predicted using the code CAGEN, validating our predictive modeling tools. The measured data is important to understanding generator performance, and is measured with a low-risk, minimally intrusive approach.
White, A D; Anderson, R A; Javedani, J B; Reisman, D B; Goerz, D A; Ferriera, A J; Speer, R D
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...
The intensity of betatron radiation emission as a function of injection voltage was studied using a 25-Mev betatron with a 350-kw external electron injector. The injection voltage was measured every 20 to 30 kw from 50 to 250 kw. The results showed that up to 250 kw, emission intensity increases according to theory. It is suggested that an increase in injection intensity up to 1000 kw and over should result in a considerable rise in emission intensity. (R.V.J.)
Moskalev, V.A.; Okulov, B.V.
Chloromethyl chlorosulfate (CMCS) is used as a passive film growth inhibitor in electrochemical cells to minimize voltage delay and low-voltage discharge. Film growth on lithium anodes is significantly diminished when CMCS is added to SOCl{sub 2} and SO{sub 2}Cl{sub 2} electrolytes of lithium batteries. The CMCS also has the effect of extending the shelf-life of Li/SOCl{sub 2} and Li/SO{sub 2}Cl{sub 2} batteries.
Training Manual for Micro, Small and Medium Entrepreneurs in...
Training Manual for Micro, Small and Medium Entrepreneurs in Energy Business Financing Jump to: navigation, search Tool Summary Name: Training Manual for Micro, Small and Medium...
Georgia Power - Small and Medium Scale Advanced Solar Initiative...
Small and Medium Scale Advanced Solar Initiative (GPASI) (Georgia) Georgia Power - Small and Medium Scale Advanced Solar Initiative (GPASI) (Georgia) Eligibility Agricultural...
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
TE Connectivity Finds Answers in Tomography
TE Connectivity Finds Answers in TE Connectivity Finds Answers in Tomography TE Connectivity Finds Answers in Tomography Print Thursday, 22 August 2013 10:50 TE Connectivity is a world leader in connectivity-the $13 billion global company designs and manufactures more than 500,000 different electronic connectivity products for the automotive, energy, industrial, broadband communications, consumer device, healthcare, aerospace, and defense industries. TE Connectivity has a long-standing commitment to innovation and engineering excellence. Their products help address challenges arising from companies' need for energy efficiency, always-on communications, and ever-increasing productivity. Recently, a team led by TE's senior manager of materials development, Dr. Jerzy Gazda (at left), has been investigating how ALS tomography capabilities can help the company develop more efficient connectors.
The impact of different voltage source converter (VSC) faults on the low voltage ride through (LVRT) capability of the doubly fed induction generator (DFIG) is also investigated. Faults such as fire-through of the VSC switches and short circuit across the DC-link capacitor are considered in this paper. The impact of internal VSC faults when they occur within the grid side converter (GSC)
Category:MediumOffice | Open Energy Information
MediumOffice MediumOffice Jump to: navigation, search Go Back to PV Economics By Building Type Media in category "MediumOffice" The following 77 files are in this category, out of 77 total. SVMediumOffice Bismarck ND Montana-Dakota Utilities Co (North Dakota).png SVMediumOffice Bismarc... 72 KB SVMediumOffice Cedar City UT Moon Lake Electric Assn Inc (Utah).png SVMediumOffice Cedar C... 62 KB SVMediumOffice International Falls MN Northern States Power Co (Minnesota) Excel Energy.png SVMediumOffice Interna... 83 KB SVMediumOffice LA CA City of Los Angeles California (Utility Company).png SVMediumOffice LA CA C... 87 KB SVMediumOffice Memphis TN City of Memphis Tennessee (Utility Company).png SVMediumOffice Memphis... 65 KB SVMediumOffice Minneapolis MN Northern States Power Co (Minnesota) Excel Energy.png
Impact of Increasing Distributed Wind Power and Wind Turbine Siting on Rural Distribution Feeder Voltage Profiles: Preprint
Many favorable wind energy resources in North America are located in remote locations without direct access to the transmission grid. Building transmission lines to connect remotely-located wind power plants to large load centers has become a barrier to increasing wind power penetration in North America. By connecting utility-sized megawatt-scale wind turbines to the distribution system, wind power supplied to consumers could be increased greatly. However, the impact of including megawatt-scale wind turbines on distribution feeders needs to be studied. The work presented here examined the impact that siting and power output of megawatt-scale wind turbines have on distribution feeder voltage. This is the start of work to present a general guide to megawatt-scale wind turbine impact on the distribution feeder and finding the amount of wind power that can be added without adversely impacting the distribution feeder operation, reliability, and power quality.
Allen, A.; Zhang, Y. C.; Hodge, B. M.
Solar collector having a solid transmission medium
There is provided a radiant energy transmission device capable of operation in a concentrative mode in which energy incident on an entrance area is directed toward and concentrated on an exit area of smaller area than the entrance area. The device includes a solid radiant energy transmission medium having surfaces coincident with the entrance and exit areas and particularly contoured reflective side walls. The surface coinciding with the entrance area is coupled to a cover plate formed of a radiant energy transmissive material. An energy transducer is coupled to the surface of the medium coinciding with the exit area.
Schertz, William W. (Batavia, IL); Zwerdling, Solomon (Woodridge, IL)
Transmission Requirements for Off-Shore Wind Integration: A study of the merits of AC and HVDC transmission connection options
This report presents a study of two transmission technologies, AC and HVDC, that could be employed to connect a distant wind farm to the Great Britain (GB) electricity transmission system. A review of the GB electricity transmission system industry codes makes it clear that particular consideration must be given in the design stage to the power factor and voltage control requirements at the interface between the wind farm and the transmission system. The ability of the transmission link and the wind ...
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
Virtual worlds as a medium for advertising
Online virtual worlds, such as Second Life, are rapidly becoming recognized as a technology of substantial future importance for marketers and advertisers. Many of these virtual worlds provide the potential medium for very rich and varied new and enhanced ... Keywords: MMOG, advertising, marketing, online game, second life, virtual world
Stuart Barnes
Medium energy heavy ion operations at RHIC
As part of the search for a phase transition or critical point on the QCD phase diagram, an energy scan including 5 different energy settings was performed during the 2010 RHIC heavy ion run. While the top beam energy for heavy ions is at 100 GeV/n and the lowest achieved energy setpoint was significantly below RHICs injection energy of approximately 10 GeV/n, we also provided beams for data taking in a medium energy range above injection energy and below top beam energy. This paper reviews RHIC experience and challenges for RHIC medium energy operations that produced full experimental data sets at beam energies of 31.2 GeV/n and 19.5 GeV/n. The medium energy AuAu run covered two beam energies, both above the RHIC injection energy of 9.8 GeV but well below the standard store energy of 100 GeV (see table 1). The low energy and full energy runs with heavy ions in FY10 are summarized in [1] and [2]. Stochastic Cooling ([3]) was only used for 100 GeV beams and not used in the medium energy run. The efficiency of the transition from 100 GeV operation to 31.2 GeV and then to 19.5 GeV was remarkable. Setup took 32 h and 19 h respectively for the two energy settings. The time in store, defined to be the percentage of time RHIC provides beams in physics conditions versus calendar time, was approximately 52% for the entire FY10 heavy ion run. In both medium energy runs it was well above this average, 68% for 31.5 GeV and 82% for 19.5 GeV. For both energies RHIC was filled with 111 bunches with 1.2 10{sup 9} and 1.3 10{sup 9} ions per bunch respectively.
Drees, K.A.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blackler, I.M.C.; Blaskiewicz, M.; Brown, K.A.; Brennan, M.; Bruno, D.; Butler, J.; Carlson, C.; Connolly, R.; D'Ottavio, T.; Fischer, W.; Fu, W.; Gassner, D.; Harvey, M.; Hayes, T.; Huang, H.; Hulsart, R.; Ingrassia, P.; Kling, N.; Lafky, M.; Laster, J.; Lee, R.C.; Litvinenko, V.; Luo, Y.; MacKay, W.W.; Marr, G.; Mapes. M.; Marusic, A.; Mernick, K.; Michnoff, R.; Minty, M.; Montag, C.; Morris, J.; Naylor, C.; Nemesure, S.; Pilat, F.; Ptitsyn, V.; Robert-Demolaize, G.; Roser, T.; Sampson, P.; Satogata, T.; Schoefer, V.; Schultheiss, C.; Severino, F.; Shrey, T.; Smith, K.S.; Tepikian, S.; Thieberger, P.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; van Kuik, B.; Wilinski, M.; Zaltsman, A.; Zeno, K.; Zhang, S.Y.
String Connections and Chern-Simons Theory
We present a finite-dimensional and smooth formulation of string structures on spin bundles. It uses trivializations of the Chern-Simons 2-gerbe associated to this bundle. Our formulation is particularly suitable to deal with string connections. We prove that every string structure admits a string connection and that the possible choices form a contractible space. We also provide a new relation between string connections and 3-forms on the base manifold.
Waldorf, Konrad
Advanced Vehicle Testing Activity: Medium- and Heavy-Duty Vehicles
Medium- and Medium- and Heavy-Duty Vehicles to someone by E-mail Share Advanced Vehicle Testing Activity: Medium- and Heavy-Duty Vehicles on Facebook Tweet about Advanced Vehicle Testing Activity: Medium- and Heavy-Duty Vehicles on Twitter Bookmark Advanced Vehicle Testing Activity: Medium- and Heavy-Duty Vehicles on Google Bookmark Advanced Vehicle Testing Activity: Medium- and Heavy-Duty Vehicles on Delicious Rank Advanced Vehicle Testing Activity: Medium- and Heavy-Duty Vehicles on Digg Find More places to share Advanced Vehicle Testing Activity: Medium- and Heavy-Duty Vehicles on AddThis.com... Home Overview Light-Duty Vehicles Medium- and Heavy-Duty Vehicles Transit Vehicles Trucks Idle Reduction Oil Bypass Filter Airport Ground Support Equipment Medium and Heavy Duty Hybrid Electric Vehicles
Requirements for a Standard Test to Rate the Durability of PV Modules at System Voltage (Presentation)
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.
Impact of MOSFET's performance on its threshold voltage and its influence on design of MOS inverters
The aim of this paper is to research the impact of physical parameters which characterize the MOSFET transistors structure on the threshold voltage values and its influence on critical voltage values which characterize digital circuits that contain the ... Keywords: MOSFET parameters, critical values, doped density, enhancement-type NMOS, impurities, narrow-channel, propagation delay, short-channel, threshold voltage, voltage level
Milaim Zabeli; Nebi Caka; Myzafere Limani; Qamil Kabashi
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.
Minimization of voltage deviation and power losses in power networks using Pareto optimization methods
Voltage regulation is an important task in electrical engineering for controlling node voltages in a power network. A widely used solution for the problem of voltage regulation is based on adjusting the taps in under load tap changers (ULTCs) power transformers ... Keywords: Multi-objective optimization, Power distribution network, Power losses, Under load tap changers, Voltage regulation
Francisco G. Montoya; Ra�l Ba�os; Consolaci�n Gil; Antonio Esp�n; Alfredo Alcayde; Julio G�mez
Elevated voltage level I.sub.DDQ failure testing of integrated circuits
Burn in testing of static CMOS IC's is eliminated by I.sub.DDQ testing at elevated voltage levels. These voltage levels are at least 25% higher than the normal operating voltage for the IC but are below voltage levels that would cause damage to the chip.
Righter, Alan W. (Albuquerque, NM)
Evaluation of PEGIT duct connection system
flex duct-to-sheet metal). Air sealing is separate from thisconcentrate on the air sealing. The connections designed byeffect of production tolerance on air sealing and assembly
Walker, Iain S.; Brenner, Douglas E.; Sherman, Max H.; Dickerhoff, Darryl J.
Utility Grid-Connected Distributed Power Systems
Grid-Connected Distributed Power Systems National Solar Energy Conference ASES Solar 96 Asheville, NC April 1996 Donald E. OsbornDavid E. Collier Sacramento Municipal Utility...
On Generating Random Network Structures: Connected Graphs
are presented for random generation of connected graphs, sugraphs (sub- graphs on the ... a distribution and take it into account at estimation. Attainability is�...
??The purpose of this study was to investigate the issues impacting the home-school connection, by exploring the following questions: What issues do parents face that� (more)
Brown, Kristin N.
Jump to: navigation, search Project Name GROWDERS Demonstration of Grid Connected Electricity Systems Country Spain Coordinates 40.338169, -3.438721 Loading map......
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
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))
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.
Mining closed relational graphs with connectivity constraints
Relational graphs are widely used in modeling large scale networks such as biological networks and social networks. In this kind of graph, connectivity becomes critical in identifying highly associated groups and clusters. In this paper, we investigate ... Keywords: closed pattern, connectivity, graph
Xifeng Yan; X. Jasmine Zhou; Jiawei Han
Quantum Mechanics and Multiply Connected Spaces
t is well known that the difference between Quantum Mechanics and Classical Theory appears most crucially in the non Classical spin half of the former theory and the Wilson-Sommerfelt quantization rule. We argue that this is symptomatic of the fact that Quantum Theory is actually a theory in multiply connected space while Classical Theory operates in simply connected space.
B. G. Sidharth
Security of internet-connected computer networks
The security of computer networks connected to the internet is an important, vital and hotly contested real-world issue. Once the computer networks get connected to the internet, the number of attacks, their strength and intensity grow exponentially. ... Keywords: attack detection, attacks, computer networks, digital signature, incidents, internet, network security, security breaches, security policy
I. Tutanescu; E. Sofron; M. Ali
JC3 Medium Impact Assessment Bulletins
medium-impact-assessment-bulletins medium-impact-assessment-bulletins Office of the Chief Information Officer 1000 Independence Ave., SW Washington, DC 202-586-0166 en V-237: TYPO3 Security Bypass Vulnerabilities http://energy.gov/cio/articles/v-237-typo3-security-bypass-vulnerabilities V-237: TYPO3 Security Bypass Vulnerabilities TYPO3 comes with the possibility to restrict editors to certain file actions (copy, delete, move etc.) and to restrict these actions to be
Alternative Fuels Data Center: Medium-Duty Vehicle Idle Reduction
Alternative Fuels and Advanced Vehicles Data Center (EERE)
Medium-Duty Vehicle Medium-Duty Vehicle Idle Reduction Strategies to someone by E-mail Share Alternative Fuels Data Center: Medium-Duty Vehicle Idle Reduction Strategies on Facebook Tweet about Alternative Fuels Data Center: Medium-Duty Vehicle Idle Reduction Strategies on Twitter Bookmark Alternative Fuels Data Center: Medium-Duty Vehicle Idle Reduction Strategies on Google Bookmark Alternative Fuels Data Center: Medium-Duty Vehicle Idle Reduction Strategies on Delicious Rank Alternative Fuels Data Center: Medium-Duty Vehicle Idle Reduction Strategies on Digg Find More places to share Alternative Fuels Data Center: Medium-Duty Vehicle Idle Reduction Strategies on AddThis.com... More in this section... Idle Reduction Benefits & Considerations Heavy-Duty Vehicles Medium-Duty Vehicles
Connecting the Americas 2022 | Department of Energy
Connecting the Americas 2022 Connecting the Americas 2022 Connecting the Americas 2022 April 16, 2012 - 8:42am Addthis At the Sixth Summit of the Americas in Cartagena, Colombia, the United States joined Colombia and other leaders of the Western Hemisphere in committing to achieve universal access to electricity over the next decade through enhanced electrical interconnection. This initiative, developed by Colombia and called "Connecting the Americas 2022"will increase access to reliable, clean, and affordable electricity for the region's 31 million citizens without it. Connecting the Americas 2022 supports the Energy and Climate Partnership of the Americas (ECPA), launched by President Obama at the 2009 Summit of the Americas, which promotes regional collaboration on low-carbon development, energy security, and climate
Instructions for WebVPN Connectivity
Instructions for WebVPN Connectivity Instructions for WebVPN Connectivity November 2013 Requirements * Web Browser (Internet Explorer, Firefox, Safari, Internet Explorer, etc.) * Internet Connection (Preferably Broadband) * RSA Token or HSPD12 Smart Card Background The clientless WebVPN connectivity option being offered by the OCIO significantly enhances the speed as well as the interoperability between different operating systems/Internet service providers (ISP) which results in an improved overall user experience when using VPN services to access corporate applications remotely. WebVPN allows a remote user to access Outlook Web Access, Citrix Workplace Environment (CWE), and other web-based applications from any computer with an Internet connection, with no requirement for additional software to be downloaded and installed to the remote machine.
Ultra-compact Marx-type high-voltage generator
An ultra-compact Marx-type high-voltage generator includes individual high-performance components that are closely coupled and integrated into an extremely compact assembly. In one embodiment, a repetitively-switched, ultra-compact Marx generator includes low-profile, annular-shaped, high-voltage, ceramic capacitors with contoured edges and coplanar extended electrodes used for primary energy storage; low-profile, low-inductance, high-voltage, pressurized gas switches with compact gas envelopes suitably designed to be integrated with the annular capacitors; feed-forward, high-voltage, ceramic capacitors attached across successive switch-capacitor-switch stages to couple the necessary energy forward to sufficiently overvoltage the spark gap of the next in-line switch; optimally shaped electrodes and insulator surfaces to reduce electric field stresses in the weakest regions where dissimilar materials meet, and to spread the fields more evenly throughout the dielectric materials, allowing them to operate closer to their intrinsic breakdown levels; and uses manufacturing and assembly methods to integrate the capacitors and switches into stages that can be arranged into a low-profile Marx generator.
Goerz, David A. (Brentwood, CA); Wilson, Michael J. (Modesto, CA)
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.
Stability issues in IC Low Drop Out voltage regulators
Performance issues of IC Low Drop Out (LDO) voltage regulators, with specific reference to stability, are discussed in this thesis. Evaluation of existing frequency compensation schemes and their performances across operating loads is presented. The problem of instability of the LDO voltage regulator at low Electo Static Resistance (ESR) of the load capacitors and the consequences of this problem are highlighted. As a solution to some of the discussed problems, an alternate LDO voltage regulator topology that is stable with low Electro Static Resistance (ESR) capacitive loads is presented. The proposed scheme, instead of relying on the zero generated by the load capacitor and its ESR combination for stability, generates a zero internally. The LDO voltage regulator is implemented and fabricated in AMI 0.5mm CMOS technology through MOSIS service. It is demonstrated that this scheme realizes robust frequency compensation, facilitates use of Multi Layer Ceramic Capacitors (MLCC) for load of LDO regulators, and improves transient response and noise performance. Test results from the prototype provide an evaluation of the most important parameters of the regulator: ground current, load regulation, line regulation, output noise and start-up time.
Chava, Krishna Chaitanya
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
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))
Hierarchical Control Scheme for Voltage Unbalance Compensation in Islanded Microgrids
Hierarchical Control Scheme for Voltage Unbalance Compensation in Islanded Microgrids firstname.lastname@example.com Abstract-- The concept of microgrid hierarchical control is presented, recently. In this paper, a hierarchical scheme which includes primary and secondary control levels is proposed for islanded microgrids
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
High Voltage Laboratory Testing of Femtosecond Laser Lightning Diversion
Lightning strikes cost the electric power industry an estimated 1 billion dollars annually in damage and lost revenue. One possible way of protecting critical and susceptible facilities from lightning strikes is to use lasers to trigger and divert lightning along a predetermined path. This report describes laboratory research on the use of ultrashort UV pulses and near IR pulses to trigger high voltage discharge.
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)
Current isolating epitaxial buffer layers for high voltage photodiode array
An array of photodiodes in series on a common semi-insulating substrate has a non-conductive buffer layer between the photodiodes and the semi-insulating substrate. The buffer layer reduces current injection leakage between the photodiodes of the array and allows optical energy to be converted to high voltage electrical energy.
Morse, Jeffrey D. (Martinez, CA); Cooper, Gregory A. (Pleasant Hill, CA)
Design of Low Voltage Low Power Operational Amplifier
With the demand of low power applications, running circuits with reduced supply voltage can be of great advantage. Integrated circuit designers start to face a power wall as the most difficult constraints in new technology and circuit development are ... Keywords: Op Amp, CMOS, LVLP
Manju Sandhu; Manju Bala
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
High voltage bipolar-CMOS structure using porous silicon
A method for integrating a silicon-on-insulator device and a bulk bipolar device on a semiconductor body. The invention simultaneously forms the two regions for the silicon-on-insulator device and the bipolar device. The invention enables a high voltage CMOS power device to be located on the same chip as a bipolar logic device enabling smart power devices.
Guilinger, T.R.; Kelly, M.J.; Tsao, S.S.
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
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
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.
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.
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
Low Beam Voltage, 10 MW, L-Band Cluster Klystron
Conceptual design of a multi-beam klystron (MBK) for possible ILC and Project X applications is presented. The chief distinction between this MBK design and existing 10-MW MBK's is the low operating voltage of 60 kV. There are at least four compelling reasons that justify development at this time of a low-voltage MBK, namely (1) no pulse transformer; (2) no oil tank for high-voltage components and for the tube socket; (3) no high-voltage cables; and (4) modulator would be a compact 60-kV IGBT switching circuit. The proposed klystron consists of four clusters containing six beams each. The tube has common input and output cavities for all 24 beams, and individual gain cavities for each cluster. A closely related optional configuration, also for a 10 MW tube, would involve four totally independent cavity clusters with four independent input cavities and four 2.5 MW output ports, all within a common magnetic circuit. This option has appeal because the output waveguides would not require a controlled atmosphere, and because it would be easier to achieve phase and amplitude stability as required in individual SC accelerator cavities.
Teryaev, V.; /Novosibirsk, IYF; Yakovlev, V.P.; /Fermilab; Kazakov, S.; /KEK, Tsukuba; Hirshfield, J.L.; /Yale U. /Omega-P, New Haven
Low Pore Connectivity in Natural Rock
As repositories for CO? and radioactive waste, as oil and gas reservoirs, and as contaminated sites needing remediation, rock formations play a central role in energy and environmental management. The connectivity of the rock's porespace strongly affects fluid flow and solute transport. This work examines pore connectivity and its implications for fluid flow and chemical transport. Three experimental approaches (imbibition, tracer concentration profiles, and imaging) were used in combination with network modeling. In the imbibition results, three types of imbibition slope [log (cumulative imbibition) vs. log (imbibition time)] were found: the classical 0.5, plus 0.26, and 0.26 transitioning to 0.5. The imbibition slope of 0.26 seen in Indiana sandstone, metagraywacke, and Barnett shale indicates low pore connectivity, in contrast to the slope of 0.5 seen in the well-connected Berea sandstone. In the tracer profile work, rocks exhibited different distances to the plateau porosity, consistent with the pore connectivity from the imbibition tests. Injection of a molten metal into connected pore spaces, followed by 2-D imaging of the solidified alloy in polished thin sections, allowed direct assessment of pore structure and lateral connection in the rock samples. Pore-scale network modeling gave results consistent with measurements, confirming pore connectivity as the underlying cause of both anomalous behaviors: imbibition slope not having the classical value of 0.5, and accessible porosity being a function of distance from the edge. A poorly connected porespace will exhibit anomalous behavior in fluid flow and chemical transport, such as a lower imbibition slope (in air�water system) and diffusion rate than expected from classical behavior.
Hu, Qinhong; Ewing, Robert P.; Dultz, Stefan
High-voltage supply for neutron tubes in well-logging applications
A high voltage supply is provided for a neutron tube used in well logging. The biased pulse supply of the invention combines DC and full pulse techniques and produces a target voltage comprising a substantial negative DC bias component on which is superimposed a pulse whose negative peak provides the desired negative voltage level for the neutron tube. The target voltage is preferably generated using voltage doubling techniques and employing a voltage source which generates bipolar pulse pairs having an amplitude corresponding to the DC bias level.
Humphreys, D.R.
Chiral Restoration in the Nuclear Medium
The photoproduction of vector mesons on various nuclei has been studied using the CLAS detector at Jefferson Laboratory. The vector mesons, rho, omega, and [cursive phi], are observed via their decay to e+e?, in order to reduce the effects of final state interactions in the nucleus. Of particular interest are possible in-medium effects on the properties of the rho meson. The rho mass spectrum is extracted from the data on various nuclei, D2, C, Fe, and Ti. We observe no significant mass shift and some broadening consistent with expected collisional broadening for the rho meson.
C. Djalali; R. Nasseripour; D. P. Weygand; M. H. Wood
Nuclear medium effects from hadronic atoms
The state of the art in the study of pionic, kaonic and Sigmionic atoms, along with the in-medium nuclear interactions deduced for these hadrons, is reviewed. A special emphasis is placed on recent developments in antikaon-nuclear physics, where a strongly attractive density dependent antikaon-nuclear potential of order 150-200 MeV in nuclear matter emerges by fitting K^- atom data. This has interesting repercussions on antikaon quasibound nuclear states, on the composition of strange hadronic matter and on kaon condensation in self bound hadronic systems.
Friedman, E
Casimir force in the presence of a medium
We investigate the Casimir effect in the presence of a medium by quantizing the electromagnetic field in the presence of a magnetodielectric medium using the path-integral technique. For a given medium with definite electric and magnetic susceptibilities, explicit expressions for the Casimir force are obtained. The Lifshitz formula is recovered and in the absence of a medium the results tend to the original Casimir force between two conducting parallel plates immersed in the quantum electromagnetic vacuum.
Kheirandish, Fardin; Soltani, Morteza; Sarabadani, Jalal [Department of Physics, University of Isfahan, Isfahan 81746, Iran and Quantum Optics Research Group, University of Isfahan, Hezar Jarib Avenue, Isfahan 81746 (Iran, Islamic Republic of); Department of Physics, University of Isfahan, Isfahan 81746 (Iran, Islamic Republic of)
Energy Education BASS CONNECTIONS in ENERGY
Energy Education BASS CONNECTIONS in ENERGY Leader: Prof. Richard Newell Duke University Energy Initiative Energy education at Duke capitalizes on the University's broader Energy Initiative, a university-wide interdisciplinary collaboration addressing today's pressing energy challenges related to the economy
Ferrari, Silvia
SSH: secure login connections over the internet
SSH provides secure login, file transfer, X11, and TCP/IP connections over an untrusted network. It uses cryptographic authentication, automatic session encryption, and integrity protection for transferred data. RSA is used for key exchange and authentication, ...
Tatu Yl�nen
Connected Consumption: The hidden networks of consumption
In this paper, we present the Connected Consumption Network (CCN) that allows a community of consumers to collaboratively sense the market from a mobile device, enabling more informed financial decisions in geo-local ...
Reed, David P.
Zone heated diesel particulate filter electrical connection
An electrical connection system for a particulate filter is provided. The system includes: a particulate filter (PF) disposed within an outer shell wherein the PF is segmented into a plurality of heating zones; an outer mat disposed between the particulate filter and the outer shell; an electrical connector coupled to the outer shell of the PF; and a plurality of printed circuit connections that extend along the outer surface of the PF from the electrical connector to the plurality of heating zones.
Gonze, Eugene V. (Pinckney, MI); Paratore, Jr., Michael J. (Howell, MI)
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
Analysis of Solar Cell Quality Using Voltage Metrics: Preprint
The highest efficiency solar cells provide both excellent voltage and current. Of these, the open-circuit voltage (Voc) is more frequently viewed as an indicator of the material quality. However, since the Voc also depends on the band gap of the material, the difference between the band gap and the Voc is a better metric for comparing material quality of unlike materials. To take this one step further, since Voc also depends on the shape of the absorption edge, we propose to use the ultimate metric: the difference between the measured Voc and the Voc calculated from the external quantum efficiency using a detailed balance approach. This metric is less sensitive to changes in cell design and definition of band gap. The paper defines how to implement this metric and demonstrates how it can be useful in tracking improvements in Voc, especially as Voc approaches its theoretical maximum.
Toberer, E. S.; Tamboli, A. C.; Steiner, M.; Kurtz, S.
SRAM leakage suppression by minimizing standby supply voltage
Suppressing the leakage current in memories is critical in low-power design. By reducing the standby supply voltage (VDD) to its limit, which is the Data Retention Voltage (DRV), leakage power can be substantially reduced. This paper explores how low DRV can be in a standard low leakage SRAM module and analyzes how DRV is affected by parameters such as process variations, chip temperature, and transistor sizing. An analytical model for DRV as a function of process and design parameters is presented, and forms the base for further design space explorations. This model is verified using simulations as well as measurements from a 4KB SRAM chip in a 0.13?m technology. It is demonstrated that an SRAM cell state can be preserved at sub-300mV standby V DD, with more than 90 % leakage power savings. 1.
Huifang Qin; Yu Cao; Dejan Markovic; Andrei Vladimirescu; Jan Rabaey
Methods for improving solar cell open circuit voltage
A method for producing a solar cell having an increased open circuit voltage. A layer of cadmium sulfide (CdS) produced by a chemical spray technique and having residual chlorides is exposed to a flow of hydrogen sulfide (H.sub.2 S) heated to a temperature of 400.degree.-600.degree. C. The residual chlorides are reduced and any remaining CdCl.sub.2 is converted to CdS. A heterojunction is formed over the CdS and electrodes are formed. Application of chromium as the positive electrode results in a further increase in the open circuit voltage available from the H.sub.2 S-treated solar cell.
Jordan, John F. (El Paso, TX); Singh, Vijay P. (El Paso, TX)
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
Guidelines for Working at Voltages < 240 Volts
Guidelines for Working at Voltages < 240 Volts Guidelines for Working at Voltages < 240 Volts February 4, 2005---DRAFT NOTE: Working hot is a LAST ALTERNATIVE. Electrical hot work is defined as: Working on or near exposed conducting parts that are or might become energized at 50V or more. Refer to Electrical Safety Flowchart for Working On or Near Live Parts. Engineered methods to prevent exposed sources of 50V and greater are to be implemented wherever practical. Only QUALIFIED PERSONNEL {as defined in NFPA 70E Article 110.6(D) 2004 edition} as authorized by the CAT/supervisor/division can perform such work. Refer to Qualified Electrical Worker Flow Chart. Training requirements: ES&H 114 (LOTO) / ES&H 375 (NFPA 70E) / ES&H 371 (electrical worker) - Observe Electrical Safe Work Practices. Refer to
Neutrino Propagation in a Strongly Magnetized Medium
We derive general expressions at the one-loop level for the coefficients of the covariant structure of the neutrino self-energy in the presence of a constant magnetic field. The neutrino energy spectrum and index of refraction are obtained for neutral and charged media in the strong-field limit ($M_{W}\\gg \\sqrt{B}\\gg m_{e},T,\\mu ,| \\mathbf{p}| $) using the lowest Landau level approximation. The results found within the lowest Landau level approximation are numerically validated, summing in all Landau levels, for strong $B\\gg T^{2}$ and weakly-strong $B \\gtrsim T^{2}$ fields. The neutrino energy in leading order of the Fermi coupling constant is expressed as the sum of three terms: a kinetic-energy term, a term of interaction between the magnetic field and an induced neutrino magnetic moment, and a rest-energy term. The leading radiative correction to the kinetic-energy term depends linearly on the magnetic field strength and is independent of the chemical potential. The other two terms are only present in a charged medium. For strong and weakly-strong fields, it is found that the field-dependent correction to the neutrino energy in a neutral medium is much larger than the thermal one. Possible applications to cosmology and astrophysics are considered.
E. Elizalde; E. J. Ferrer; V. de la Incera
Plutonium Management in the Medium Term
For many years various countries with access to commercial reprocessing services have been routinely recycling plutonium as UO{sub 2}/PuO{sub 2} mixed oxide (MOX) fuel in light water reactors (LWRs). This LWR MOX recycle strategy is still widely regarded as an interim step leading to the eventual establishment of sustainable fast reactor fuel cycles. The OECD/NEA Working Party on the Physics of Plutonium Fuels and Innovative Fuel Cycles (WPPR) has recently completed a review of the technical options for plutonium management in what it refers to as the 'medium term'. For the purpose of the review, the WPPR considers the medium term to cover the period from now up to the point at which fast reactor fuel cycles are established on a commercial scale. The review identified a number of different designs of innovative plutonium fuel assemblies intended to be used in current LWR cores, in LWRs with significantly different moderation properties, as well as in high-temperature gas reactors. The full review report describes these various options and highlights their respective advantages and disadvantages. This paper briefly summarizes the main findings of the review.
Hesketh, Kevin [BNFL Nuclear Sciences and Technology Services (United Kingdom); Schlosser, Gerhard; Porsch, Dieter F. [Framatome ANP (France); Wolf, Timm [Framatome ANP (France); Koeberl, Oliver [CEA Cadarache (France); Lance, Benoit [Belgonucleaire (Belgium); Chawla, Rakesh [Paul Scherrer Institut (Switzerland); Gehin, Jess C. [Oak Ridge National Laboratory (United States); Ellis, Ron [Oak Ridge National Laboratory (United States); Uchikawa, Sadao [Japan Atomic Energy Research Institute (Japan); Sato, Osamu [Japan Atomic Energy Research Institute (Japan); Okubo, Tsutomu [Japan Atomic Energy Research Institute (Japan); Mineo, Hideaki [Japan Atomic Energy Research Institute (Japan); Yamamoto, Toru [Nuclear Power Engineering Corporation (Japan); Sagayama, Yutaka [Japan Nuclear Cycle Development Institute (Japan); Sartori, Enrico [Organization for Economic Cooperation and Development (France)
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: 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 ...
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 ...
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 ...
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
Advanced Gate Drive for the SNS High Voltage Converter Modulator
SLAC National Accelerator Laboratory is developing a next generation H-bridge switch plate [1], a critical component of the SNS High Voltage Converter Modulator [2]. As part of that effort, a new IGBT gate driver has been developed. The drivers are an integral part of the switch plate, which are essential to ensuring fault-tolerant, high-performance operation of the modulator. The redesigned driver improves upon the existing gate drive in several ways. The new gate driver has improved fault detection and suppression capabilities; suppression of shoot-through and over-voltage conditions, monitoring of dI/dt and Vce(sat) for fast over-current detection and suppression, and redundant power isolation are some of the added features. In addition, triggering insertion delay is reduced by a factor of four compared to the existing driver. This paper details the design and performance of the new IGBT gate driver. A simplified schematic and description of the construction are included. The operation of the fast over-current detection circuits, active IGBT over-voltage protection circuit, shoot-through prevention circuitry, and control power isolation breakdown detection circuit are discussed.
Nguyen, M.N.; Burkhart, C.; Kemp, M.A.; /SLAC; Anderson, D.E.; /Oak Ridge
Ultra-low voltage resonant tunnelling diode electroabsorption modulator
Embedding a double barrier resonant tunnelling diode (RTD) in an unipolar InGaAlAs optical waveguide gives rise to a very low driving voltage electroabsorption modulator (EAM) at optical wavelengths around 1550 nm. The presence of the RTD within the waveguide core introduces high non-linearity and negative differential resistance in the current-voltage (I-V) characteristic of the waveguide. This makes the electric field distribution across the waveguide core strongly dependent on the bias voltage: when the current decreases from the peak to the valley there is an increase of the electric field across the depleted core. The electric field enhancement in the core-depleted layer causes the Franz-Keldysh absorption band-edge to red shift, which is responsible for the electroabsorption effect. High frequency ac signals as low as 100 mV can induce electric field high speed switching, producing substantial light modulation (up to 15 dB) at photon energies slightly lower than the waveguide core band-gap energy. The k...
Figueiredo, J M L; Stanley, C R
765kV Transmission line Voltage gradient
Corona ring Transmission lines Nowadays, due to the ever increasing energy consumption and power supply optimization, it is required to construct new power plants, substations and transmission lines. In Iran, also, because of increasing demand for electrical energy, for a significant power loss reduction in power transmission over long distances, and to construct high transmission lines that lead to reduction in the economic costs of transmission lines, the transmission lines must be considered at extra high voltage (EHV) levels. These EHV levels should be compared with the low voltage levels in order to extract the benefits. Therefore, in this paper, a review has been conducted on the types of 765 kV transmission lines used in different countries and a comparison between them and the low voltage levels have been performed. Accordingly, the advantages of EHV transmission lines are summarized. Finally, designing a line of 765 kV single-circuit with 6 conductors per bundle based on existing standards is presented.
Near independence of OLED operating voltage on transport layer thickness
We report organic light emitting devices (OLEDs) with weak drive voltage dependence on the thickness of the hole transport layer (HTL) for thicknesses up to 1150 � using the N,N?-Bis(naphthalen-1-yl)-N,N?-bis(phenyl)-benzidine (?-NPD) and N,N'-bis(3-methyl phenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'diamine (TPD), both of which have hole mobilities in the range of 2 � 10-3 cm2V-1s-1. Lower mobility HTL materials show larger operating voltage dependence on thickness. The near independence of the operating voltage for high mobility transport material thickness was only observed when the energy barrier for charge injection into the transport material was minimized. To ensure low injection barriers, a thin film of 2-(3-(adamantan-1-yl)propyl)-3,5,6-trifluorotetracyanoquinodimethane (F3TCNQ-Adl) was cast from solution onto the ITO surface. These results indicate that thick transport layers can be integrated into OLED stacks without the need for bulk conductivity doping.
Swensen, James S.; Wang, Liang (Frank) [Frank; Polikarpov, Evgueni; Rainbolt, James E.; Koech, Phillip K.; Cosimbescu, Lelia; Padmaperuma, Asanga B.
Cerenkov radiation in a causal permeable medium
A classical and a fully quantum mechanical treatment is presented for the Cerenkov radiation stimulated by a uniformly moving charge particle. The dissipated energy of the electron is decomposed into two parts: the radiative energy density which is associated with the transverse part of the field operators and the nonradiative energy density which is connected with the longitudinal part of the field operators. Special attention is paid to the different limits of this formalism, and the results are compared with previous works. We also look at the Cerenkov radiation in left-handed materials.
Matloob, R.; Ghaffari, A. [Department of Physics, University of Kerman, Kerman (Iran, Islamic Republic of)
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
Monitoring Volume Transport through Measurement of Cable Voltage across the Korea Strait
Voltage induced by the Tsushima Current on an abandoned submarine telephone cable between Pusan, Korea, and Hamada, Japan, has been measured since March 1998 in order to monitor the volume transport through the Korea Strait. Voltage has a good ...
Kuh Kim; Sang Jin Lyu; Young-Gyu Kim; Byung Ho Choi; Keisuke Taira; Henry T. Perkins; William J. Teague; Jeffrey W. Book
Lipon Coatings for High Voltage and High Temperature Li-Ion ...
use of high-capacity and high-voltage cathode materials, but charging to voltages approaching 4.5-5V invariably causes rapid loss of capacity with cycling.
Voltage holding study of 1 MeV accelerator for ITER neutral beam injectora)
Voltage holding test on MeV accelerator indicated that sustainable voltage was a half of that of ideal quasi-Rogowski electrode. It was suggested that the emission of the clumps is enhanced by a local electric field concentration
M. Taniguchi; M. Kashiwagi; N. Umeda; M. Dairaku; J. Takemoto; H. Tobari; K. Tsuchida; H. Yamanaka; K. Watanabe; A. Kojima; M. Hanada; K. Sakamoto; T. Inoue
A low-voltage zero-crossing-based delta-sigma analog-to-digital converter
A zero-crossing-based (ZCB) switched-capacitor technique is presented for operation under low power supply voltages without gate boosting. Voltage ramp generators maintain common-mode level at each integrator output. ...
Guyton, Matthew C. (Matthew Christopher)
A low-noise bandgap voltage reference employing dynamic element matching
Bandgap voltages references are widely used in IC design, but are sensitive to low-frequency noise and component mismatch. This thesis describes the design and testing of a new IC voltage reference that targets these issues ...
Herbst, Steven (Steven G.)
BB5, Nearly Ideal Current-Voltage Characteristics of Schottky Barrier ...
Recently, high-quality GaN free-standing substrates are available by various methods. ... Current-voltage (I-V) characteristics and capacitance-voltage (C-V)�...
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 ...
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...
Building Technologies Office: Small- and Medium-Sized Building Automation
Small- and Medium-Sized Small- and Medium-Sized Building Automation and Control System Needs: Scoping Study Research Project to someone by E-mail Share Building Technologies Office: Small- and Medium-Sized Building Automation and Control System Needs: Scoping Study Research Project on Facebook Tweet about Building Technologies Office: Small- and Medium-Sized Building Automation and Control System Needs: Scoping Study Research Project on Twitter Bookmark Building Technologies Office: Small- and Medium-Sized Building Automation and Control System Needs: Scoping Study Research Project on Google Bookmark Building Technologies Office: Small- and Medium-Sized Building Automation and Control System Needs: Scoping Study Research Project on Delicious Rank Building Technologies Office: Small- and Medium-Sized Building
Alternative Fuels Data Center: Medium-Speed and Neighborhood Electric
Medium-Speed and Medium-Speed and Neighborhood Electric Vehicle (NEV) Definition and Access to Roadways to someone by E-mail Share Alternative Fuels Data Center: Medium-Speed and Neighborhood Electric Vehicle (NEV) Definition and Access to Roadways on Facebook Tweet about Alternative Fuels Data Center: Medium-Speed and Neighborhood Electric Vehicle (NEV) Definition and Access to Roadways on Twitter Bookmark Alternative Fuels Data Center: Medium-Speed and Neighborhood Electric Vehicle (NEV) Definition and Access to Roadways on Google Bookmark Alternative Fuels Data Center: Medium-Speed and Neighborhood Electric Vehicle (NEV) Definition and Access to Roadways on Delicious Rank Alternative Fuels Data Center: Medium-Speed and Neighborhood Electric Vehicle (NEV) Definition and Access to Roadways on Digg
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.
Conserving the Connections: A Nationwide Inventory of State-Based Habitat Connectivity Analysis
NC Gringas, Glen. 2007. Vermont Agency of Transportation.Morse and J. Austin. 2003. Vermont Agency of Transportationecological connectivity in Vermont. Montpelier, VT. http://
Feinberg, Jesse
The mathematics connection : a curriculum promoting mathematical application through the home-school connection
homework: An experiment in home and school connections.thought processes. Through home math activities studentsis a similar problem to the home math activity but at an
Komatsubara, Kristin Mie
An Ultra-Compact Marx-Type High-Voltage Generator
This paper discusses the design of an ultra-compact, Marx-type, high-voltage generator. This system incorporates high-performance components that are closely coupled and integrated into an extremely compact assembly. Low profile, custom ceramic capacitors with coplanar extended electrodes provide primary energy storage. Low-inductance, spark-gap switches incorporate miniature gas cavities imbedded within the central region of the annular shaped capacitors, with very thin dielectric sections separating the energy storage capacitors. Carefully shaped electrodes and insulator surfaces are used throughout to minimize field enhancements, reduce fields at triple-point regions, and enable operation at stress levels closer to the intrinsic breakdown limits of the dielectric materials. Specially shaped resistors and inductors are used for charging and isolation during operation. Forward-coupling ceramic capacitors are connected across successive switch-capacitor-switch stages to assist in switching. Pressurized SF, gas is used for electrical insulation in the spark-gap switches and throughout the unit. The pressure housing is constructed entirely of dielectric materials, with segments that interlock with the low-profile switch bodies to provide an integrated support structure for all of the components. This ultra-compact Marx generator employs a modular design that can be sized as needed for a particular application. Units have been assembled with 4, 10, and 30 stages and operated at levels up to 100 kV per stage.
Goerz, D; Ferriera, T; Nelson, D; Speer, R; Wilson, M
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.
New model for well test analysis in a purely fractured medium
In a porous medium the flow conduits are small and a large number of conduits are connected to the well. For this reason the medium appears to behave like a continuum on the scale of the well test, and volumetric averaging and continuum approximations are justified. On the contrary, in a fractured medium, only a small number of fractures may intersect the pumping well. These particular fractures will be stressed by a large gradient under well test conditions. Consequently, the early time behavior will be dominated by these fractures. The volumetrically averaged permeability does not control flow in the vicinity of an active well. The individual fractures close to the well must be characterized in order to understand the well test behavior especially if the hydraulic parameters of these fractures are significantly different from the average values for the entire system. In the present study, a new analytical model is proposed for well test problems in fracture networks where the matrix is impermeable. The model accounts for the difference in the flow regime around the active well from that of the system as a whole. The analytical solutions are presented in a series of type curves for ranges of dimensionless parameters. The flow properties of the fracture system can be determined by curve matching.
Karasaki, K.; Long, J.C.S.; Witherspoon, P.A.
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
Modeling and simulation of new configuration of dynamic voltage restorer for power quality improvement
The dynamic voltage restorer (DVR) is a custom device that is used to maintain the voltage at the load terminals from various power quality problems from a disturbed incoming supply. In this paper, a novel control strategy is described for mitigation ... Keywords: custom device, dynamic voltage restorer (DVR), power quality, sags, sensitive loads, swells
Rosli Omar; Nasrudin Abdul Rahim
Currents' Physical Components (CPC) In Circuits with Nonsinusoidal Voltages and Currents
voltages and currents. It is true only for balanced loads supplied with a symmetrical voltage. However{ || || || || || || }P u u uY Y Y+ + . (20) The supply voltage is sinusoidal and symmetrical, thus RS ST TR R for energy permanent conversion in the load with power P. The remaining part of the supply current, i ia
Czarnecki, Leszek S.
Charging-choke circuit with a crowbar for precision control of voltage
The operation of a circuit using a charging choke to obtain dc voltages is improved by constructing the circuit to be capable of producing a higher voltage than the desired value and crowbarring the charging choke when the load voltage reaches the desired value.
Praeg, W.F.
Analysis the operation of DVR in voltage sag mitigation using EMTP
According to the reports, voltage sag is the most probable voltage problem in the network. As the number of sensitive loads increases rapidly the demand for a reliable and cost effective solution also has been increased. In this paper we are going to ... Keywords: DVR, custom power, distribution network, voltage sag
H. Monsef; B. Tamimi
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
Energy Minimization Using Multiple Supply Voltages Jui-Ming Chang and Massoud Pedram
Energy Minimization Using Multiple Supply Voltages Jui-Ming Chang and Massoud Pedram Department and energy costs of these level shifters must be taken into account when comparing a multiple-supply voltage a dynamic programming technique for solv- ing the multiple supply voltage scheduling problem in both non
Pedram, Massoud
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
CMOS flash analog-to-digital converter for high speed and low voltage applications
A CMOS flash analog-to-digital converter (ADC) designed for high speed and low voltage is presented. Using the Threshold Inverter Quantization (TIQ) comparator technique, a flash ADC can be applied to low supply voltage. A fat tree encoder that has signal ... Keywords: TIQ comparator, analog-to-digital converter, fat tree encoder, flash ADC, high speed, low voltage
Jincheol Yoo; Kyusun Choi; Jahan Ghaznavi
Medium energy charged particle data for evaluation
Medium energy charged particles incident on targets can cause a variety of nuclear reactions. Charged particle transport calculations require access to a large body of cross-section data which results in interest in an evaluated charge particle data library. Developing an evaluated data library can involve several steps. An index to the literature on measurements and theory is useful to locate information relevant to data evaluation. A computerized compilation of measurements facilitates the intercomparison of different experiments and the determination of how well data are known. Nuclear models, based on theory or phenonological evidence, are compared with experiment and where validated, are used to fill in regions where experimental data are not available. Finally, the selected data is placed into computer readable formats for use in transport calculations. 16 refs.
Turbulence in the Molecular Interstellar Medium
Abstract. The observational record of turbulence within the molecular gas phase of the interstellar medium is summarized. We briefly review the analysis methods used to recover the velocity structure function from spectroscopic imaging and the application of these tools on sets of cloud data. These studies identify a near-invariant velocity structure function that is independent of local the environment and star formation activity. Such universality accounts for the cloud-to-cloud scaling law between the global line-width and size of molecular clouds found by Larson (1981) and constrains the degree to which supersonic turbulence can regulate star formation. In addition, the evidence for large scale driving sources necessary to sustain supersonic flows is summarized.
Mark H. Heyer; Chris Brunt
A model for the critical voltage for electrical degradation of GaN high electron mobility transistors
We have found that there is a critical drain-to-gate voltage beyond which GaN high-electron mobility transistors start to degrade in electrical-stress experiments. The critical voltage depends on the detailed voltage biasing ...
Joh, Jungwoo
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.
Changes related to "Connections to Electricity Use Data and Informatio...
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NineStar Connect - Residential Energy Efficient Equipment Rebate...
NineStar Connect - Residential Energy Efficient Equipment Rebate Program NineStar Connect - Residential Energy Efficient Equipment Rebate Program Eligibility Residential Savings...
Modeling Electric Vehicle Benefits Connected to Smart Grids
Electric Vehicle Benefits Connected to Smart Grids Title Modeling Electric Vehicle Benefits Connected to Smart Grids Publication Type Conference Proceedings LBNL Report Number...
What Connects Rat Tails to Cancer and Heart Disease?
What Connects Rat Tails to Cancer and Heart Disease? Collagen is the main (and most abundant) protein in all mammalian connective tissues, including those of the heart, lungs,...
Benefits Connected to Smart Grids M. Stadler 1,2,a , C.Benefits Connected to Smart Grids Michael Stadler , Chris
Stadler, Michael
Connecting the Connecting the Molecular and the Continuum Scales Connecting the Molecular and the Continuum Scales Key Challenges: A molecular-scale understanding of structure and surface chemistry of clay mineral surface nanoparticles. Why it Matters: With a ubiquitous presence in natural materials and strong surface reactions, nanoparticles figure importantly in a broad range of phenomena, from climate change to contaminant remediation. Accomplishments: Used molecular dynamics (MD) simulations to determine molecular-scale diffusion coefficients of water tracers and representative cations (Na+,Cs+,Sr2+) in Smectite and found a simple way to accurately relate this to bulk, pore-scale diffusion. The result is that a remarkably simple expression relates Dinterlayer to the pore-scale
EnergyConnect | Open Energy Information
EnergyConnect EnergyConnect Jump to: navigation, search Name EnergyConnect Address 51 East Campbell Avenue, Suite 145 Place Campbell, California Zip 95008 Sector Efficiency Product Demand response system provider/operator Website http://www.energyconnectinc.co Coordinates 37.287725°, -121.948704° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":37.287725,"lon":-121.948704,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}
LR: Compact connectivity representation for triangle meshes
We propose LR (Laced Ring) - a simple data structure for representing the connectivity of manifold triangle meshes. LR provides the option to store on average either 1.08 references per triangle or 26.2 bits per triangle. Its construction, from an input mesh that supports constant-time adjacency queries, has linear space and time complexity, and involves ordering most vertices along a nearly-Hamiltonian cycle. LR is best suited for applications that process meshes with fixed connectivity, as any changes to the connectivity require the data structure to be rebuilt. We provide an implementation of the set of standard random-access, constant-time operators for traversing a mesh, and show that LR often saves both space and traversal time over competing representations.
Gurung, T; Luffel, M; Lindstrom, P; Rossignac, J
Connected Energy Corp | Open Energy Information
Connected Energy Corp Connected Energy Corp Jump to: navigation, search Name Connected Energy Corp Place Rochester, New York Zip 14614 Product Developer of the Central Operation Management System (COMSYS). Coordinates 43.1555°, -77.616033° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":43.1555,"lon":-77.616033,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}
WindConnect | Open Energy Information
WindConnect WindConnect Jump to: navigation, search Name WindConnect Place Madison, Wisconsin Zip 53707-1007 Sector Services Product Unit of Alliant Energy. It provides turnkey services such as design, engineering, and construction. Coordinates 43.07295°, -89.386694° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":43.07295,"lon":-89.386694,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}
Nobel Prize | Other BNL Nobel Proze Connections
Other BNL Nobel Prize Connections Other BNL Nobel Prize Connections 2008: Crystal Structure of Green Fluorescent Protein Roger Y. Tsien, University of California, San Diego, Nobel Prize in Chemistry Green fluorescent protein (GFP), which glows green under ultraviolet light, has become a ubiquitous tool in bioscience. It turns out that the structure of GFP was first solved with the help of x-ray studies at Brookhaven's National Synchrotron Light Source. Tsien was an author on that seminal paper. 2004: Studies of the "Strong" Force Frank Wilczek, Massachusetts Institute of Technology, Nobel Prize in Physics Wilcek's work as a theoretical physicist brought him to Brookhaven Lab several times. His first connection with the lab began in 1976, when he worked as an assistant visiting physicist from June to July. He returned in
Nuclear Maintenance Applications Center: Post-Trip Voltage Prediction at Nuclear and Other Generating Stations
The objective of this Electric Power Research Institute (EPRI) project is to investigate the possibility of predicting the switchyard voltage in a nuclear power plant (NPP) following a trip of a nuclear unit. Two methods of post-trip voltage prediction are investigated. The first method, called the V-Q method, uses minimal local plant information (such as unit operating conditionsactive and reactive power output and pre-trip voltage) to predict post-trip voltage based on the sensitivity of voltage to the...
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)
DOE NHI: Progress in Nuclear Connection Technologies
The U.S. Department of Energy Nuclear Hydrogen Initiative (NHI) is seeking to develop the technologies to enable the large-scale production of hydrogen from water using a nuclear powered heat source. A necessary component in any nuclear powered hydrogen production process is the energy transfer connection between the nuclear plant and the hydrogen plant. This article provides an overview of the research and development work that has been accomplished on the high-temperature heat transfer connection between the nuclear power plant and the hydrogen production plant by the NHI. A description of future work is also provided.
Steven R. Sherman
Electrically conductive connection for an electrode
An electrically conductive connection for an electrode assembly of an electrolyte cell in which aluminum is produced by electrolysis in a molten salt is described. The electrode assembly comprises an electrode flask and a conductor rod. The flask has a collar above an area of minimum flask diameter. The electrically conductive connection comprises the electrode flask, the conductor rod and a structure bearing against the collar and the conductor rod for pulling the conductor rod into compressive and electrical contact with the flask. 2 figs.
Hornack, T.R.; Chilko, R.J.
Induction of nuclear fission by high-voltage application
In nuclear power generation, fissile materials are mainly used. For example, $U^{235}$ is fissile and therefore quite essential for use of nuclear energy. However, the material $U^{235}$ has very small natural abundance less than 1 %. We should seek possibility of utilizing fissionable materials such as $U^{238}$ because natural abundance of such fissionable materials is generally much larger than fissile ones. In this paper, we show that thermal neutrons with vanishing kinetic energy can induce nuclear fission when high voltage is applied to fissionable materials. To obtain this result, we use the liquid-drop model for nuclei. Finally, we propose how fissionable materials can be utilized.
Hirokazu Maruyama
High Voltage Direct Current Live Line and Insulator Testing
This report has two main parts. The focus of the first part is on live work in overhead high-voltage direct current (HVDC) lines operating above 100 kV dc. It does not address issues related to lines for electric transport that typically operate below 60 kV dc worldwide. In addition, this first part of the report is not a detailed treatise on live work but, rather, addresses the main issues related to dc live work. More detailed information on the general topic of live work can be found in the references...
Self-monitoring high voltage transmission line suspension insulator
A high voltage transmission line suspension insulator (18 or 22) which monitors its own dielectric integrity. A dielectric rod (10) has one larger diameter end fitting attachable to a transmission line and another larger diameter end fitting attachable to a support tower. The rod is enclosed in a dielectric tube (14) which is hermetically sealed to the rod's end fittings such that a liquidtight space (20) is formed between the rod and the tube. A pressurized dielectric liquid is placed within that space. A discoloring dye placed within this space is used to detect the loss of the pressurized liquid.
Stemler, Gary E. (Vancouver, WA); Scott, Donald N. (Vancouver, WA)
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.
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.