Three-Phase Four-Wire DSTATCOM with Reduced Switches for Power Quality Improvement

Asian Power Electronics Journal 2.

ABSTRACT In this paper, a two-leg VSC (voltage source converter) integrated with a star/hexagon transformer is used for the power quality improvement in three-phase four-wire distribution system. The primary winding of the transformer is star connected and it provides a path to the zero sequence fundamental as well as harmonics neutral currents. The secondary windings of the transformer are connected in hexagon manner and it provides isolation to the two-leg VSC. In order to optimise the voltage rating of the two-leg VSC, the secondary winding of the transformer is suitably designed. The proposed DSTATCOM (Distribution Static Compensator) provides the voltage regulation or power factor correction by reactive power compensation, harmonics elimination, load balancing and neutral current compensation in three-phase four-wire distribution system. This topology has the advantages of the use of 'off the shelf' two-leg VSC, reduced size and cost. The rating of the transformer remains same when it is compensating the neutral current due to unabalance in the load. The performance of the proposed DSTATCOM system is validated through simulations using MATLAB software with its Simulink and Power System Blockset (PSB) toolboxes.

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Available from: D.P. Kothari, Sep 25, 2015
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    • "The loads connected at the PCC are three-phase four-wire unbalanced linear/ nonlinear loads [14]. In proposed sliding mode control, the dynamic operation depends upon the small variation in DC link voltage under sudden change in load conditions. "
    IEEE PEDES 2014; 12/2014
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    • "The shunt active filter (SHAF) is an inverter driven to generate compensating currents that attenuate the harmonic components generated by the nonlinear loads [1]. Therefore, only the fundamental current component would be delivered by the main supply. "
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    ABSTRACT: This research article presents a novel approach based on an instantaneous active and reactive power component (p-q) theory for generating reference currents for shunt active filter (SHAF). Three-phase reference current waveforms generated by proposed scheme are tracked by the three-phase voltage source converter in a hysteresis band control scheme. The performance of the SHAF using the p-q control strategy has been evaluated under various source conditions. The performance of the proposed control strategy has been evaluated in terms of harmonic mitigation and DC link voltage regulation. In order to maintain DC link voltage constant and to generate the compensating reference currents, we have developed Fuzzy logic controller with different (Trapezoidal, Triangular and Gaussian) fuzzy M.F.s. The proposed SHAF with different fuzzy M.F.s is able to eliminate the uncertainty in the system and SHAF gains outstanding compensation abilities. The detailed simulation results using MATLAB/SIMULINK software are presented to support the feasibility of proposed control strategy. To validate the proposed approach, the system is also implemented on a real time digital simulator and adequate results are reported for its verifications.
    Journal of power electronics 09/2012; 12(5). DOI:10.6113/JPE.2012.12.5.821 · 0.78 Impact Factor
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    ABSTRACT: This paper deals with a software phase locked loop (SPLL) based control algorithm for a three phase distribution static compensator (DSTATCOM) for power quality improvement under linear/nonlinear loads in a distribution system. In this control approach, amplitude of fundamental active and reactive power components of load currents is extracted for estimation of reference source currents. The DSTATCOM is modeled in the Matlab environment using Simulink and Sim Power System (SPS) toolboxes. Matlab based developed model of DSTATCOM is used to simulate its performance. Simulated performance of DSTATCOM is found satisfactory under time varying and unbalanced linear and nonlinear consumer loads.
    Power Electronics (IICPE), 2012 IEEE 5th India International Conference on; 01/2012
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