Four-Leg VSI Based DSTATCOM for Compensating Nonlinear and Unbalanced Loads

This paper presents a study on the four-leg VSI based distribution static compensator (D-STATCOM) for compensation of neutral, source & PCC current harmonic distortion, PCC voltage regulation and compensation of unbalanced in current waveform. This solution could be used for three-phase four-wire nonlinear and unbalanced load medium voltage distribution system. The proposed control algorithm is developed based on synchronous reference frame theory with the PI controller. The obtained reference current signal from control algorithm is compared in hysteresis band current controller for a better switching of the D-STATCOM. The performance of the system with implementing the D-STATCOM is also analyzed and compared. The proposed control method is implemented on 11/0.4kv medium voltage distribution system and provided effective compensation for reactive power and harmonic distortion mitigation. The simulation results are obtained using MATLAB/SIMULINK