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Fixed Pitch Wind Turbine-Based Permanent Magnet Synchronous Machine Model for Wind Energy Conversion Systems
Janardan Gupta, Ashwani Kumar
January-June 2012, 2(1):52-62
DOI:10.4103/0976-8580.94226
The countries all over the world have emphasis on green energy and wind systems can play a vital role for renewable energy systems. In this work, real value model of wind turbine has been formulated. The mechanical torque and power captured by the wind turbine has also been verified for the real value WT Model. The fixed pitch wind-driven wind turbine model has been utilized for generation of power with permanent magnet synchronous machine (PMSM). This paper presents a dynamic model of a microturbine generation system. The components of the system are built from the dynamics of each part with their interconnections. The model is implemented in the MATLAB/Simulink using SimPower Systems library. The performance of the implemented model is studied with an isolated load. The SIMULINK model of the entire system with wind turbine has been developed and the results are obtained for voltage and current waveforms on load end side as well as for PMSM. The current and voltage waveforms are obtained with RL and LCL filter.
[ABSTRACT] [FULL TEXT] [PDF] [Mobile Full text] [EPub] [CITATIONS]
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Neeraj Sharma, Tilak Raj, Kamal Kumar Jangra
January-June 2015, 5(1):1-7
DOI:10.4103/0976-8580.149472
Nitinol exists in equiatomic phase of nickel-titanium (Ni-Ti). Nitinol has various applications in biomedical, automotive actuators, micro-electromechanical systems (MEMSs) and aero-space industries due to its distinctive properties of pseudo-elasticity, bio-compatibility, corrosion resistance and shape memory effect. This paper presents the applications of nickel-titanium alloy in various field of engineering, medical and other area. The attractive properties of NiTi alloy has also been discussed that makes it most influential material for various applications.
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Parametric Optimization of Cryogenic-Treated D-3 for Cutting Rate in Wire Electrical Discharge Machining
Hari Singh, Rajesh Khanna
July-December 2011, 1(2):59-64
Cryogenic treatment ("Cryo") is a supplementary process to improve the properties of metals like high carbon high chromium alloy tool steels (D-3) which are increasingly used in manufacturing high-performance cutting tools (dies and punches), blanking and punching tools, extrusion tools, parts of aerospace and automotive industries, etc. The purpose of this study is to investigate the effect of parameters like pulse width, time between two pulses, maximum feed rate, servo reference mean voltage, short pulse time, and wire mechanical tension, on cutting rate (cr) of cryogenic-treated D-3 in wire electrical discharge machining. An L27 orthogonal array has been used to conduct experiments and statistically evaluate the experimental data by analysis of variance (ANOVA). It is seen that cr decreases with increase in pulse width, time between two pulses, and servo reference mean voltage. cr first decreases and then increases with increase in wire mechanical tension. The confirmation experiments have also been conducted to validate the results obtained by Taguchi technique.
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Effects of Cryogenic Treatment on High-speed Steel Tools
Lakhwinder Pal Singh, Jagtar Singh
High-speed steel (HSS) tools are the most commonly used tools in small and medium-scale industry. So far, a few studies have been carried out pertaining to the life of HSS single point cutting tool. Studies on cryogenically treated (CT) cutting tools show microstructural changes in the material that can influence the life of the tools significantly. This paper primarily reports performance of CT HSS tools as compared to untreated (UT) HSS tools. The results show that CT HSS tools exhibit better performance based on tool wear, surface roughness of the work specimen, and power consumption during operation than the UT HSS tools.
Depiction of Total Quality Management during a Span of 2003-2013
Vineet Gupta, Dixit Garg, Raj Kumar
The tenacity of this article is to craft a depiction of one decade's quality movement. The progression of the depiction, aims to ease in establishing the existing standing of total quality management (TQM) and endorse in accepting and influencing its imminent course. In this effort, potential circulated articles during that period under the question of TQM have been collected. The collected data further analyzed and reflected in order to show the delineations, elements and methods that have been cited by various scholars, professionals, academics, etc. The outcomes display the basic to build a renowned philosophy in terms of employee's empowerment, ownership, leadership, cultural change, continuous improvements, etc., based on facts and focus on the customer satisfaction have been increasing more during the last decade.
Effect of Height on Seismic Response of Reinforced Cement Concrete Framed Buildings with Curtailed Shear Wall
RS Malik, SK Madan, VK Sehgal
Reinforced cement concrete (RCC) framed structures combined with shear walls have been widely used to resist lateral forces during earthquakes in tall buildings. Shear walls are generally provided for full height of the frames. Lateral forces are carried mostly by frames in the upper portion of the building and shear walls contribute the least in this region. This concept has been extended to 10, 20, and 30 storeyed symmetric RCC buildings with curtailment of shear walls at various heights. Efforts have been made to study the effect of height on the curtailment of shear wall. Three-dimensional models of RC special moment resisting frames have been analyzed using STAAD-Pro (Research Engineers, USA, 2005) software. The results show that curtailment of shear wall up to 50% height of the building, has a marginal effect on the distribution of horizontal storey shear among the shear wall frames and interior frames. But height of the building has a significant role in storey shear distribution.
A Censoring and Quantization Scheme for Energy-Based Target Localization in Wireless Sensor Networks
Zhenxing Luo
This article presents a censoring and quantization scheme for energy-based target localization in wireless sensor networks (WSNs). This scheme can save energy and communication bandwidth. Moreover, a multi-objective optimization method is used to balance the energy consumption and target localization performance of the energy-based target localization method using this scheme. Results show that the root square mean (RMS) errors provided by the energy-based target localization method using this scheme were close to the Cramer-Rao lower bound (CRLB). Moreover, the Pareto-fronts provided by the multi-objective optimization method can guide practical applications.
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Power System Steady State Monitoring Using Artificial Neural Network
SG Ankaliki, SG Gollagi
This article presents the application of Artificial Neural Network (ANN) for steady state monitoring of a power system. In steady state monitoring of a power system, it is important to predict the line flows and bus voltages for different operating conditions. In this article ANN has been proposed as an alternative method to solve the power system problems where the desired speed has not been achieved by conventional methods. The proposed method describes an adoptive pattern recognition approach based on highly parallel information processing. We provide a pattern of system description parameters to a neural network and net returns an estimate of line flows and bus voltages. Training data were obtained by Newton Rapson load flow simulation using Mipower Software Simulation Package for different system topologies over a range of load levels and the results were compiled to form the training data set. A back propagation algorithm was used for training ANN. Results of this approach help the power system operator to successfully handle the topologically independent steady state security assessment. To illustrate the proposed approach, IEEE-14 Bus system was considered. The difference between the actual and the estimated power flows and bus voltages was found to be good in terms of accuracy.
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Energy Efficiency Improvement Strategies for Industrial Boilers: A Case Study
Rahul Dev Gupta, Sudhir Ghai, Ajai Jain
In this paper, the findings of boiler house efficiency improvement study carried out in a large boiler house unit of a pulp and paper mill has been presented. The causes of poor boiler efficiency were various heat losses such as loss due to unburnt carbon in refuse, loss due to dry flue gas, loss due to moisture in fuel, loss due to radiation, loss due to blow down, and loss due to burning hydrogen, etc. The various heat losses were analyzed and a set of recommendations were made to the plant management for implementation, so that efficiency of boiler can be increased. Five important recommendations were implemented by plant management, and it has been seen that there is tremendous increase in boiler efficiency. Economic analysis reveals that the expenditure on the proposed system will be recovered in a short span of time. This work, with only five recommendations implemented, has resulted in net increase of 2% in overall boiler efficiency and an annual saving of Rs. 34,12,395. In addition, it is observed that carefulness in the operation of boiler can help a great deal in energy efficiency improvement in boiler.
Zulfiqar Ali Soomro
January-June 2015, 5(1):8-13
The rail wheelset dynamics has skeleton importance to avoid the slip and slide due to insufficient adhesion level depending on creep forces. Proper study and control upon lateral and yaw motion owing to creep forces may reduce the problem at some extent. In this paper, this dynamics of wheelset with its possible degree of freedom has been discussed and limited to lateral and yaw analysis. These analyses have been computed and simulated by simulink to observe their behavior. The disturbances of these dynamical parameters are estimated using Kalman filter. The correlation of actual and estimated curves has been assessed to invent novel idea.
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Effect of Process Parameters on Kerf Width in WEDM for HSLA Using Response Surface Methodology
Pardeep Gupta, Rajesh Khanna, Rahul Dev Gupta, Neeraj Sharma
Wire electric discharge machine (WEDM) is a spark erosion machining process to cut very hard conductive material with the help of a wire electrode. High strength low alloy steel (HSLA) is a hard alloy with high hardness and wear resisting property. The purpose of this study is to investigate the effect of parameters on kerf width for WEDM using HSLA as workpiece. HSLA is used in cars, trucks, cranes, bridges, roller coasters and other structures that are designed to handle large amounts of stress. It is revealed that kerf width decreases with increase in pulse on time, pulse off time, spark gap voltage and peak current. Kerf width increases with increase in wire tension. In order to evaluate the effect of selected process parameters, the response surface methodology (RSM) is used to formulate a mathematical model which correlates the independent process parameters with the desired kerf width. The central composite rotatable design has been used to conduct the experiments. The analysis of results indicates that the spark gap voltage, pulse on time, peak current and pulse off time have a significant effect on kerf width.
Electrical Energy Auditing and Harmonic Analysis of Industrial Units: A Case Study
Pankaj Oberoi, SK Aggarwal
July-December 2011, 1(2):113-119
In any industry, the three top operating expenses are often found to be on energy, labor and materials. If one were to find out the potential cost savings in each of the components, energy would invariably emerge at the top, and thus energy management function constitutes a strategic area for cost reduction. This paper discusses the common aspects of electrical energy management in small- and medium-sized industries. It contains the findings and the analysis of the results obtained from the electrical energy audit program employed in an industrial unit, Isolloyds Engineering Technologies Ltd. (Baddi, Himachal Pradesh). The electrical energy audit was carried out under four major heads: (i) lighting audit, (ii) Heating Ventilation Air Conditioning (HVAC) audit, (iii) power load audit (motors, melter, etc.), and (iv) harmonic analysis. Readings were taken under these heads and analyzed to find the scope of energy conservation opportunities in the selected test case industrial unit.
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Low-Power High-Speed Small Area Hybrid CMOS Full Adder
Amit Gupta, RK Sharma, Rasika Dhavse
A 20-transistor hybrid CMOS full adder circuit using small area transistors has been proposed. The circuit layout is designed with 0.18-μm n-well CMOS design rules. The post layout simulation has been carried out using TSMC018 technology file. The proposed adder circuit provides fully restored logic levels at the output for all input combinations up to an operating frequency of more than 500 MHz. The power dissipation, rise and fall times, and worst-case propagation delay as obtained from the proposed adder have been found to be better in comparison to other full adder circuits (which provide fully restored logic levels at the output) reported in the literature.
Stochastic Dynamic Job Shop Scheduling with Sequence-Dependent Setup Times: Simulation Experimentation
Pankaj Sharma, Ajai Jain
Stochastic dynamic job shop (SDJS) scheduling problems with sequence-dependent setup times are among the most difficult classes of scheduling problems. This paper assesses the performance of five dispatching rules (DRLs) in such shop from makespan, mean flow time, mean tardiness, number of tardy jobs, total setups, and mean setup time performance measures viewpoint. A discrete event simulation model of a SDJS manufacturing system is developed for investigation purpose. Five DRLs, that is, first come first serve (FCFS), shortest processing time (SPT), shortest setup time (SIMSET), earliest due date (EDD) and shortest sum of setup times and processing time (SSPT) are incorporated in the simulation model. The simulation experiments are conducted under due date tightness factor of 3, shop utilization percentage of 90 and setup time less than processing time. Results indicate that SIMSET rule provides best performance for mean flow time and number of tardy jobs performance measures. The SPT rule provides best performance for mean tardiness measure. The EDD rule is best-performing DRL for makespan, total setups and mean setup time measures.
High Temperature Erosion of Flame Sprayed Coatings
Satpal Sharma
In the present work, Co-base powder was modified with 10%wt CrC addition in order to study the effect of CrC addition. These coatings were deposited by flame spraying process. The effect of CrC addition on Vickers hardness and erosive wear behavior of the deposited coatings was studied. The erosive wear behavior of flame sprayed coatings was investigated by response surface methodology. To investigate and develop the erosive wear model of the flame sprayed coatings four factors, namely velocity (V), impact angle (A), temperature (T), and feed rate (F), each factor at three levels, were used. Analysis of variance was carried out to determine the significant factors and interactions. Investigation showed that the composition, velocity, impact angle, temperature, and feed rate were the main significant factors while velocity-feed rate and impact angle - feed rate were the main significant interactions. Thus, an erosive wear model was developed in terms of main factors and their significant interactions. The validity of the model was evaluated by conducting experiments under different wear conditions. A comparison of modeled and experimental results showed 3-8% error. The CrC addition improves the erosive wear resistance of the coatings. This is due to an increase in hardness of the flame sprayed coatings with the addition of CrC.
Technology Challenges in E-Service Accessibility
Amar Jeet Singh, Rajesh Chauhan
E-governance faces many technological challenges that common enterprise often would not expect. These challenges arise out of the very nature of these systems. E-governance has the capacity to provide high-quality government services to citizens and businesses, irrespective of their status, and bringing transparency, speed, reliability, and consistency in handling governance as whole. Due to technological problems in the actual implementation of the solution, E-government solutions cannot reach the masses. E-government services are in their infancy stage in many developing countries. Currently, many E-government services are acting as passive agents and delivering static information from government to citizens rather than acting as an active agent and hold two-way communications. This paper discusses various problems that come in the path of the proliferation of E-government services.
Performance Analysis of Symmetric Multistage Voltage Multipliers
HR Zinage, SG Gollagi
A performance study of a 3-phase symmetric Cockcroft-Walton (CW)-multistage voltage multiplier (VM) is proposed. It consists of 1 smoothing column and 6 oscillating columns. The oscillating columns are connected to a 3-phase power through center-tap transformers. The capacitors of the smoothing column are charged 6 times per cycle by 6 oscillating columns and are discharged 6 times through the load, unlike the conventional symmetric VM in which they are charged and discharged twice per cycle. The 3-phase symmetric structure completely eliminates the first 5 harmonic components of load-generated voltage ripple. Theoretic analysis indicates that the proposed 3-phase symmetric CW-VM has one-third the voltage ripple and voltage drop of the conventional single-phase symmetric CW-VM. Simulation results of the proposed 3-phase symmetric CW-VM as well as those of the conventional single-phase symmetric CW-VM are presented. A comparison shows that the 3-phase symmetric CW-VM has significantly less voltage ripple, half the voltage drop, and a 4-fold increase in the output power over the conventional single-phase symmetric CW-VM.
A Paradigm to Produce Customized Ankle Support Using Incremental Sheet Forming
Vishal Gulati, Sumit Kathuria, Puneet Katyal
This paper presents a paradigm to produce customized ankle support through the use of reverse engineering (RE) process, which uses the patient's scan data to an optimal form using a computer-aided design (CAD) system and then transferring the three-dimensional CAD model to Incremental Sheet Forming (ISF) technique for the production of tangible prosthesis product. This work is in the direction of forming of such a customized ankle support that minimizes the gap between the implanting prosthesis and the ankle. Such type of products may be prefabricated or customized. Prefabricated products are manufactured according to the standard sizes of different persons and customized are fitted after observing the patient's computed tomography scan. Prefabricated products do not guaranteed that the product will fit or not to the geometry of patient. On the other side, customized products provide more comfort and satisfaction than prefabricated products. RE design process has been implemented in order to acquire CAD model from the patient's scan data and to use this information for computer controlled layered manufacturing technique like ISF.
Multi-Agent Based Cloud Service Composition using Contract Net Protocol for Information Retrieval Purpose
Yu Mon Zaw
Information retrieval (IR) systems are important key players for every Internet user and there are many Information Retrieving frameworks and algorithms, which are currently using or under development. As the technology trend is always changing and current industrial and business world is willing to emphasize on not only providing knowledge but also supporting service, cloud computing and Web Services (WSs) become popular. Cloud computing is internet based system development in which large scalable computing resources are provided "as a service" over the internet to users and has attracted more and more attention from industry and research community. WS plays important role in service oriented computing in World-Wide-Web and Cloud environment. Developing a Cloud Wide IRSystem using WSs can fill one blank of Cloud Environment. In this case, retrieving desired specific information from WSs on Cloud Environment cannot be completed by single WS. Hence, there should be a way to build an IRSystem based on a set of related WSs in order to fulfill users' requests and provide desired services. To compose WSs, Multi-Agent System (MAS) can give great help. Agent systems are self-contained software programs embodying domain knowledge and having ability to act as a specific degree of independence to carry out actions needed to accomplish desired goals. Therefore, this paper mainly focuses on building a WSs Based IR MAS framework and Agent Processing Algorithm, which will be running on a Private Cloud Environment. We propose Contract Net Protocol for IR Purpose in order to perform WSs Composition. The implementation and testing of this system utilizes the real datasets of clinics in the Yangon area.
Short-Term Load Forecasting in Deregulated Electricity Markets using Fuzzy Approach
SK Aggarwal, Manoj Kumar, LM Saini, Ashwani Kumar
In this article, a fuzzy inference-based method for short-term load forecasting has been presented. Load data from European Energy Exchange has been selected for the case study. The "time," "temperature," and "historical load" are taken as inputs for the fuzzy logic controller and the "forecast load" is the output. Each of the input variables "time" and "temperature" has been divided into 7 triangular membership functions, whereas the input variable "historical load" has been divided into 10 triangular membership functions. The "forecast load" as output has been divided into 10 triangular membership functions. Then, 1 day ahead load forecast for each hourly interval has been performed using fuzzy logic method. Furthermore, performance of the fuzzy logic model is compared with a conventional model. It has been shown that the proposed method possesses better forecasting abilities than the other model.
Adaptive nodeless variable finite element method for convectively-cooled solid
Sutthikom Puntimakornkij, Atipong Malatip, Pramote Dechaumphai
An adaptive nodeless variable finite element method for analysis of convectively-cooled solid is presented. The method solves two-dimensional heat transfer in solid coupling with one-dimensional heat transfer of fluid flow in channel. The nodeless variable finite element concept is introduced to increase the solution accuracy without adding the actual nodes. An adaptive finite element technique is incorporated to further improve the overall analysis solution accuracy. Several examples are presented to evaluate the performance of the proposed method by comparing the predicted solution with the exact solution and/or the solution from solving the full Navier-Stokes equations.
[ABSTRACT] Full text not available [PDF]
A High-Order Sliding Mode Observer: Torpedo Guidance Application
Ahmed Rhif, Zohra Kardous, Naceur BenHadj Braiek
The guidance of a torpedo represents a hard task because of the smooth nonlinear aspect of this system and because of the extreme external disturbances. The torpedo guidance reposes on the speed and the position control. In fact, the control approach which is very solicited for the electromechanical systems is the sliding mode control (SMC) which proved its effectiveness through the different studies. The SMC is robust versus disturbances and model uncertainties; however, a sharp discontinuous control is needed which induces the chattering phenomenon. The angular velocity measurement is a hard task because of the high level of disturbances. In this way, the sliding mode observer could be a solution for the velocity estimation instead of a sensor. This article deals with torpedo guidance by SMC to reach the desired path in a short time and with high precision quality. Simulation results show that this control strategy and observer can attain excellent control performances with no chattering problem.
Flow Structure and Heat Transfer Analysis in a Laminar Channel Flow with Built-in Side-by-Side Dual Triangular Prism
Munish Gupta, Rajesh Dudi, Satish Kumar
This paper presents the numerical analysis of fluid flow in a parallel plate channel having dual triangular prisms in side-by-side arrangement. The computational domain is considered two dimensional. The fluid flow is assumed to be incompressible, steady and laminar with constant thermophysical properties. The computations are performed for a Reynolds number of 100 and blockage ratio (b) of 0.25, where the blockage ratio (b) is the ratio of prism base to the channel height (b = B/H). The unstructured triangular grid is used for the computational domain. The results are compared with the channel having single triangular prism and plane channel. The channel walls are subjected to a constant wall temperature. Unsteady two-dimensional Navier Stokes and energy equations are solved numerically using a control volume method. The SIMPLE discretization algorithm is used for the convective terms in the solution equations. CFD software FLUENT 6.2 is used to simulate the fluid flow and temperature field. A preprocessor GAMBIT is used to generate the required mesh for the solver. Results illustrate that the Nusselt numbers on the channel walls are strongly modified by the vortices induced by the presence of triangular prisms. In the presence of triangular prisms, the average Nusselt number is 8.5% more as compared to plane channel and 4.5% as compared to channel having single prism at the same Reynolds number and blockage ratio.
Stability Analysis of Mode Coupling Vibration Systems with Coulomb Friction
Lilan Liu, Ziying Wu
In the article, the stability analysis of mode coupling systems with Coulomb friction is performed. A two-degree-of-freedom (2-DOF) vibration system with Coulomb friction is constructed. Taking the friction coefficient as a bifurcation parameter, a Hopf bifurcation graph is obtained using the Routh criterion. It is illustrated that Coulomb friction can induce self-excited oscillation in the mode coupling system. The analytic expressions of the limit cycle amplitudes of the oscillation system are achieved based on the extended harmonic balance method. Moreover, the effects of some parameters on the size of limit cycles are investigated. All the research method and results presented can provide a valuable reference for the structure optimal design of mechanical systems and vibration reduction.
Performance of Asymmetric Slot-Entry Hybrid Journal Bearing Operating with Non-Newtonian Lubricant
HC Garg
This article presents the theoretical investigations of the rheological effects of the lubricant on the performance of asymmetric slot-entry hybrid journal bearing system. Finite element method (FEM) has been used to solve the Reynolds equation governing the flow of lubricant in the bearing clearance space along with the restrictor flow equation. The non-Newtonian lubricant has been assumed to follow the cubic shear stress law. The simulated results of bearing characteristics parameters in terms of minimum fluid film thickness and bearing flow have been presented for the wide range of values of nonlinearity factor and external load. The computed results reveal that the variation of viscosity due to non-Newtonian behavior of the lubricant affects the performance of slot-entry hybrid journal bearing system quite significantly.