The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Mahesh K. Mishra - One of the best experts on this subject based on the ideXlab platform.
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Instantaneous Symmetrical Component Theory Based Parallel Grid Side Converter Control Strategy for Microgrid Power Management
IEEE Transactions on Sustainable Energy, 2019Co-Authors: Ram Shankar Yallamilli, Mahesh K. MishraAbstract:This paper proposes a centralized control strategy for power management of hybrid microgrid connected to the grid using a parallel combination of grid side converters (GSCs). An improved version of instantaneous Symmetrical Component theory is developed and is used for the control of parallel operated GSCs, which results in reduced sensor requirement, control complexity, and communication bandwidth. In addition, a simple power management algorithm is developed to test the efficacy of the proposed parallel grid side converter control strategy for all the microgrid modes considering state of charge limits of hybrid energy storage system, load changes, and renewable power variations. In the proposed system, a better dc link voltage regulation is achieved and usage of supercapacitor reduces the current stresses on the battery. With the proposed control strategy, the essential features of grid side converters like power quality, power injection, bidirectional power flow, and proportional power sharing are achieved. The effectiveness of the developed control strategy for the proposed system is tested using MATLAB based simulink environment and validated experimentally using a laboratory prototype.
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current sharing control strategy of parallel inverters using instantaneous Symmetrical Component theory
IEEE International Conference on Power Electronics Drives and Energy Systems, 2014Co-Authors: M Manoj V Kumar, Mahesh K. MishraAbstract:This paper presents a power sharing control algorithm for parallel grid interactive multifunctional voltage source inverters (PGMVSIs) which are connected to distributed renewable energy sources. The main objective of this scheme is to get proportional power sharing among PGMVSIs, so as to make the grid current balanced sinusoidal and at unity power factor. The control algorithm is derived using instantaneous Symmetrical Component theory (ISCT) to ensure a proper sharing of active, reactive, unbalance and harmonic power among parallel inverters. This scheme requires a central controller and communication among inverters in contrary to the droop control based techniques. However, the proposed control scheme has perfect decoupling of active and reactive power sharing, proportional unbalance and harmonic power sharing, and a very good dynamic response. The steady state and transient performance of the proposed control strategy have been verified through detailed simulation.
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instantaneous Symmetrical Component theory based algorithm for characterization of three phase distorted and unbalanced voltage sags
International Conference on Industrial Technology, 2013Co-Authors: J Suma, Mahesh K. MishraAbstract:The Dynamic Voltage Restorer (DVR) topologies, with compensation schemes that are sag type specific, require information that are not readily available from the conventional characterization techniques. New characterization algorithm which can identify the phase(s) affected and readily can give information on sag magnitude and phase angle jump are necessary. In this paper, instantaneous Symmetrical Component theory based algorithm for detection and characterization of voltage sags is proposed. Detailed simulation study of the proposed algorithm has been carried out in MATLAB and the results are presented.
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control strategies for load compensation using instantaneous Symmetrical Component theory under different supply voltages
IEEE Transactions on Power Delivery, 2008Co-Authors: U K Rao, Mahesh K. Mishra, Arindam GhoshAbstract:In this paper, the theory of instantaneous Symmetrical Components is applied to explore various control strategies of load compensation, under different supply voltages. When the supply voltages are balanced and sinusoidal, all of these strategies converge to the same compensation characteristics. However, when the supply voltages are not balanced sinusoids, these control strategies result in different degrees of compensation in harmonics, power factor, neutral current, and compensator ratings. These control strategies are discussed in detail and a comparative study of their performance in terms of the rms value, total harmonic distortion, power factor of source currents, and compensator ratings is presented. Based on this study, it is possible to select the best strategy to meet the required load compensation characteristics for available supply voltages. A three-phase four-wire distribution system supplying an unbalanced and nonlinear load is considered for simulation study. The detailed simulation results using MATLAB are presented to support the proposed compensation strategies.
Feng Gao - One of the best experts on this subject based on the ideXlab platform.
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fast Symmetrical Component extraction from unbalanced three phase signals using non nominal dq transformation
IEEE Transactions on Power Electronics, 2018Co-Authors: Tianqu Hao, Feng GaoAbstract:This letter proposes a new algorithm for the fast extraction of Symmetrical Components from unbalanced three-phase signals. Being different from the conventional methods for the decomposition of positive and negative sequence Components commonly realized at the cost of introducing significant delay, the proposed algorithm assumes the non-nominal dq -transformation to first produce the special d -axis and q -axis Components, which will become the pure high-frequency ac signals, and then uses the typical half-cycle delay method to remove the unwanted negative or positive sequence Component. Finally, the proper amplitude and phase angle coefficients can be easily calculated to compensate the remaining high-frequency d -axis and q -axis Components before transforming them to the expected d -axis and q -axis values of corresponding Symmetrical Components. The performance of the proposed algorithm is evaluated through simulation and experiment results.
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a new diagnostic method for winding short circuit fault for srm based on Symmetrical Component analysis
Chinese Journal of Electrical Engineering, 2018Co-Authors: Li Xiao, Hexu Sun, Feng Gao, Shuping HouAbstract:Winding short-circuit is one of the more common faults in switched reluctance motors (SRM). This paper takes an in-depth look at winding short-circuit. The characteristic of non-sinusoidal intermittent single phase current, fundamental Components are extracted to reconstruct four phase Symmetrical currents based on spectrum analysis of phase currents. The method of Symmetrical Component is used to calculate positive and negative sequence Components of reconstructed currents, where then the ratio between positive and negative sequence Component is seen as a fault feature and the diagnostic criterion is proposed. The simulation and experimental results are presented to confirm the implementation of the proposed method.
Gianfranco Chicco - One of the best experts on this subject based on the ideXlab platform.
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100 Years of Symmetrical Components
Energies, 2019Co-Authors: Gianfranco Chicco, Andrea MazzaAbstract:28 June 2018 was the 100th anniversary of the first presentation on Symmetrical Components made by Charles LeGeyt Fortescue at the 34th Annual Convention of the American Institute of the Electrical Engineers in Atlantic City (NJ, USA). The introduction of the Symmetrical Component concept was immediately seen as a milestone for electrical system studies, and many applications have been developed during the ensuing years. Today, refined or advanced contributions to conceptual and practical aspects of electrical applications are still being proposed based on the powerful structure of Symmetrical Components. This paper recalls the most significant steps made in the electrical engineering field after the introduction of the Symmetrical Component theory, and indicates recent developments concerning the studies on electrical machines, harmonics and interharmonics in different applications, and the operation of power and distribution systems with distributed energy resources.
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analysis of the steinmetz compensation circuit with distorted waveforms through Symmetrical Component based indicators
IEEE PowerTech Conference, 2009Co-Authors: Gianfranco Chicco, P Postolache, M Chindris, Andrei Cziker, C ToaderAbstract:This paper deals with the use of a set of indicators defined within a Symmetrical Component-based framework to study the characteristics of the Steinmetz compensation circuit in the presence of waveform distortion. The Steinmetz circuit is applied to obtain balanced currents in a three-phase system supplying a single-phase load. The circuit is analyzed without and with harmonic distortion of the supply voltages. The compensation effect is represented by the classical unbalance factor and by the Total Phase Unbalance (TPU) indicator defined in the Symmetrical Component-based framework. Comparing the two indicators, it is shown that the classical unbalance factor is insufficient to represent the effect of voltage distortion and fails to detect the lack of total unbalance compensation occurring with distorted waveforms. Correct information is provided by calculating the TPU indicator.
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analysis of three phase systems with neutral under distorted and unbalanced conditions in the Symmetrical Component based framework
IEEE Transactions on Power Delivery, 2007Co-Authors: Gianfranco Chicco, P Postolache, C ToaderAbstract:This paper introduces an original and rigorous formulation for computing the unbalance and distortion Components of phase and neutral currents in the framework of the Symmetrical Component transformation. The proposed formulation extends recent literature results, in which different matrices were used for unbalance characterization in the presence of distorted waveforms and provides, at the same time, an innovative interpretation of the neutral current waveform Components. New indicators are also defined to combine the effects of unbalance and waveform distortion, extending the set of indicators currently adopted in the power-quality standards. A set of illustrative examples is presented to show the applicability of the proposed approach. These include four circuits, two real-case applications, and an example taken from the IEEE trial-use standard 1459-2000
S Elangovan - One of the best experts on this subject based on the ideXlab platform.
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improved Symmetrical Component based fault distance estimation for digital distance protection
IEE Proceedings - Generation Transmission and Distribution, 1998Co-Authors: Y Liao, S ElangovanAbstract:An improved Symmetrical Component-based method is proposed in the paper. The proposed method uses phasor estimates of voltage and current samples obtained from both ends of a transmission line. The mathematical basis of the new approach is described. It is shown that the new method completely obviates complex arithmetic operations and has considerable computational advantages over the previously proposed methods. Furthermore, performance assessment studies on this new method using the alternative transient program (ATP) are presented and discussed. It is illustrated that the proposed method can determine the fault location very accurately and is likely to be used for digital distance protection and fault location.
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real time assessment of a Symmetrical Component and microcontroller based distance relay
Electric Power Systems Research, 1995Co-Authors: D L Waikar, S Elangovan, A C Liew, S H SngAbstract:Abstract This paper presents the design, implementation and real-time assessment of a microcontroller based digital distance relay that can be used for the protection of power transmission lines. The proposed design is implemented using a general-purpose Intel 8097 microcontroller and custom-made filters, operational amplifiers, sample-and-hold amplifiers, multiplexers, and analog-to-digital converters. The relay software is based on a computationally efficient Symmetrical Component based fault distance estimation algorithm. Results of the performance assessment studies on this algorithm have shown promising fault distance estimates for first-zone faults on the protected transmission line. Real-time implementation of the Symmetrical Component based fault distance estimation algorithm is presented and discussed in this paper. Hardware and software tools were used to design and fabricate a microcontroller based distance relay using the above-mentioned algorithm. This paper describes details of the design of the distance relay. A test setup in the laboratory using a transmission line model was used to generate data to assess the real-time response of the designed relay. High-speed relay operation of the order of one cycle is demonstrated in the test results.
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first zone performance assessment of a Symmetrical Component based improved fault impedance estimation method
Electric Power Systems Research, 1993Co-Authors: D L Waikar, A C Liew, S ElangovanAbstract:Abstract This paper describes the first-zone performance assessment of a Symmetrical Component based fault impedance estimation method that has previously been proposed by the authors. The performance equation of the proposed method is briefly reviewed and various performance assessment techniques are also discussed. The Alternative Transient Program, which is available on personal computers, was used in these performance assessment studies. This Program was used to model a power system and to simulate many fault conditions on a selected transmission line. Fault data thus obtained were used in calculating the fault impedance using the proposed method. Fault impedance estimates were inserted in R-X plane characteristics to determine the suitability of the proposed method for first-zone digital protection. The results of these performance assessment studies are presented and discussed in the paper.
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Symmetrical Component based improved fault impedance estimation method for digital distance protection part i design aspects
Electric Power Systems Research, 1993Co-Authors: D L Waikar, S Elangovan, A C LiewAbstract:Abstract Recently, distance relays using digital processors have received considerable attention from researchers. The digital processor based distance relays use estimates of fault impedance (distance) in making decisions. Several methods have been suggested in the past that can be used to estimate fault distance. Researchers have proposed Symmetrical Component, Clark's Component and modal Component theories for developing distance estimation methods. The approach used in the Symmetrical Component based methods has resulted in a higher computational burden on the digital processor, which was addressed using special hardware or multiprocessors. In the present paper, an improved method is proposed that also uses Symmetrical Component transformation. The simplified approach used in the proposed method leads to a computational advantage over previously suggested Symmetrical Component based methods. The paper derives performance equations that are valid for ten types of shunt fault encountered on transmission lines. The basis for analyzing shunt faults on the transmission line model and developing the fault estimation method is discussed in detail. The proposed method is also validated using numerical examples, the results of which are reported in Part II of this paper ( Electr. Power Syst. Res., 26 (1993) 149–154).
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Symmetrical Component based improved fault impedance estimation method for digital distance protection part ii computational aspects and validation
Electric Power Systems Research, 1993Co-Authors: D L Waikar, A C Liew, S ElangovanAbstract:Abstract Part I of the paper (Electr. Power Syst. Res., 26 (1993) 143–147) on this subject has discussed the design aspects and the basis of the improved method for fault distance calculation. This paper deals with the computational aspects and validation of the fault impedance estimation method proposed in Part I. The performance equations of two fault impedance estimation methods that are based on the Symmetrical Component theory are reviewed. Also discussed are the computational aspects of these two methods. Instruction execution cycles of a TMS-320 digital signal processor are used to determine the computational requirements of the arithmetic operations of the two methods. A comparative study is also given in this paper. Definite computational advantages of the proposed method over the previously suggested methods based on Symmetrical Component transformation are demonstrated. The proposed method of Part I is validated using numerical examples.
Yuan-yih Hsu - One of the best experts on this subject based on the ideXlab platform.
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A NOVEL APPROACH TO THE DESIGN OF A SHUNT ACTIVE FILTER UNDER NONSINUSOIDAL CONDITIONS FOR AN UNBALANCED THREE-PHASE FOUR-WIRE SYSTEM
2000Co-Authors: Cheng-che Chen, Yuan-yih HsuAbstract:A new approach is presented for the design of a shunt active filter in a three-phase, four-wire distribution system with unbalanced, distorted sources and unbalanced loads. The purpose of the shunt active filter is to provide compensation currents such that the source needs to supply balanced (positive-sequence) fi"enta1 source current at unity power factor even though the load consumes harmonic currents as well as positive, negative, and zero-sequence currents. A major feature of the proposed approach is that it does not require Symmetrical Component transformation to transform the three-phase voltages and currents to a-p-o quantities. This makes practical implementation of the proposed method easier than the Symmetrical Component transformation approach. In addition, the power factor of the positive-sequence fundamental Component is close to unity and only positive-sequence power is supplied by the source. The effectiveness of the proposed control algorithm is demonstrated by computer simulation and experimental results of a shunt active filter for a three-phase four-wire distribution system with distorted, unbalanced source voltages and unbalanced loads.
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A novel approach to the design of a shunt active filter for an unbalanced three-phase four-wire system under nonsinusoidal conditions
IEEE Transactions on Power Delivery, 2000Co-Authors: Cheng-che Chen, Yuan-yih HsuAbstract:A new approach is presented for the design of a shunt active filter in a three-phase, four-wire distribution system with unbalanced, distorted sources and unbalanced loads. The purpose of the shunt active filter is to provide compensation currents such that the source needs to supply balanced (positive-sequence) fundamental source current at unity power factor even though the load consumes harmonic currents as well as positive, negative, and zero-sequence currents. A major feature of the proposed approach is that it does not require Symmetrical Component transformation to transform the three-phase voltages and currents to /spl alpha/-/spl beta/-o quantities. This makes practical implementation of the proposed method easier than the Symmetrical Component transformation approach. In addition, the power factor of the positive-sequence fundamental Component is close to unity and only positive-sequence power is supplied by the source. The effectiveness of the proposed control algorithm is demonstrated by computer simulation and experimental results of a shunt active filter for a three-phase four-wire distribution system with distorted, unbalanced source voltages and unbalanced loads.
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A novel approach to the design of a shunt active filter for an unbalanced three-phase four-wire system under nonsinusoidal conditions
2000 Power Engineering Society Summer Meeting (Cat. No.00CH37134), 1Co-Authors: Cheng-che Chen, Yuan-yih HsuAbstract:Summary form only given as follows. A new approach is presented for the design of a shunt active filter in a three-phase, four-wire distribution system with unbalanced, distorted sources and unbalanced loads. The purpose of the shunt active filter is to provide compensation currents such that the source needs to supply balanced (positive-sequence) fundamental source current at unity power factor even though the load consumes harmonic currents as well as positive, negative, and zero-sequence currents. A major feature of the proposed approach is that it does not require Symmetrical Component transformation to transform the three-phase voltages and currents to /spl alpha/-/spl beta/-o quantities. This makes practical implementation of the proposed method easier than the Symmetrical Component transformation approach. In addition, the power factor of the positive-sequence fundamental Component is close to unity and only positive-sequence power is supplied by the source. The effectiveness of the proposed control algorithm is demonstrated by computer simulation and experimental results of a shunt active filter for a three-phase four-wire distribution system with distorted, unbalanced source voltages and unbalanced loads.
