Browsing by Author "Sharma, K.M."

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A heuristic approach for distributed generation sources location and capacity evaluation in distribution systems
(2008) Sharma, K.M.; Vittal, K.; Seshagiri, P.
Distributed Generation (DG) sources are becoming more prominent in distribution systems due to increased demand for the electrical energy. The locations and capacities of DG sources will have an impact on system losses, voltage profile characteristics of distribution network. This paper presents a heuristic approach for selection of optimal location and determination of optimal capacity of DG sources. The technique adopts Genetic Algorithms and Optimal Power Flow to facilitate the decision making process. The developed technique is incorporated with the flexibility so that the network planner can choose the total number of DGs to be included, their constraints on maximum power outputs, non-feasible locations for DG insertion which are to be excluded from search. The proposed approach is tested for IEEE 69 bus system and the results have indicated the versatility of the technique.
Harmonic current compensation improvement at point of common coupling using hybrid natural green sources
(2017) Nagaraj, C.; Sharma, K.M.
Ideally, distribution utilities are responsible to provide good power at a fixed rated frequency to the consumer end at unity power factor. Due to the bulk usage of non-linear power electronic loads, distribution system network (DSN) suffers large current distortion. Further, the intermittent hybrid natural green sources (HNGS) like PV and PMSG wind grid connected using hysteresis current controller (HCC) through 3-phase VSI effects more distortion of current which contaminates the power quality at the consumer end. Thus power quality is a vital issue which needs to be presented well in this paper. This paper adopts the shunt active filter (SHAF) using real and reactive current (id-iq) control strategy to analyze the case studies with presence and absence of HNGS under unbalanced nonlinear load condition for the reduction in current distortion at distribution utility side. The MATLAB/Simulink examined to validate the performance of id-iq control strategy. � 2017 IEEE.
A heuristic approach for distributed generation sources location and capacity evaluation in distribution systems
(2008) Sharma, K.M.; Vittal, K.P.; Seshagiri, P.
Distributed Generation (DG) sources are becoming more prominent in distribution systems due to increased demand for the electrical energy. The locations and capacities of DG sources will have an impact on system losses, voltage profile characteristics of distribution network. This paper presents a heuristic approach for selection of optimal location and determination of optimal capacity of DG sources. The technique adopts Genetic Algorithms and Optimal Power Flow to facilitate the decision making process. The developed technique is incorporated with the flexibility so that the network planner can choose the total number of DGs to be included, their constraints on maximum power outputs, non-feasible locations for DG insertion which are to be excluded from search. The proposed approach is tested for IEEE 69 bus system and the results have indicated the versatility of the technique.
Improvement of harmonic current compensation for grid integrated PV and wind hybrid renewable energy system
(2016) Nagaraj, C.; Sharma, K.M.
Ideally, electric utilities are required to supply sinusoidal voltage at constant rated frequency while end users need to receive a sinusoidal current with good power factor. Electrical power distribution systems are already experiencing distortion of the current due to the usage of non-linear power electronic loads in industrial and commercial applications. Further, the integration of intermittent hybrid renewable sources like solar and wind to the utility grid through 4-leg 3-phase 4-wire current controlled voltage source inverter (VSI) leads to cause still more current distortion which pollutes the quality of electric power at the end users. Thus power quality is a critical issue to be addressed effectively. The active power filter (APF) is advantageous over passive filter due to its capability for better harmonic compensation features. This paper presents analysis of shunt active filter (SHAF) using a PI controller with and without the incorporation of intermittent hybrid renewable sources under different grid conditions. An instantaneous real and reactive current (id-iq) control scheme for SHAF is proposed for reduction in harmonic levels. The MATLAB/Simulink simulation studies validates the performance of id-iq control method. � 2016 IEEE.
Performance analysis of robust and nonlinear MPPT controllers for autonomous wind power system
(2017) Hemachandra, G.; Sharma, K.M.
This paper presents the performance analysis of nonlinear and robust control strategies for the maximum power extraction from permanent magnet synchronous generator (PMSG) based autonomous wind energy conversion system (WECS) under varying wind speed. The Nonlinear control strategy aims to achieve improvement in speed tracking performance by using feedback linearization method used to select the optimal control input by compensating nonlinearities in the WECS directly driven by PMSG. In order to design the Robust Quantitative Feedback Theory (QFT) based controller and multi model QFT controller for the WECS based on PMSG, the nonlinear system is represented by a series of linear time invariant transfer functions around different operating points. Robust controllers are designed for proper selection of optimal control input to extract maximum power for every wind speed. Performance analysis is done from the MATLAB simulation results among the controllers for the PMSG based WECS. Multi model QFT controller is recommended for their enhanced performance. � 2016 IEEE.