Neutral Current Compensation of Three-Phase Four-wire Distribution System Using Three-Level Four-Leg DSTATCOM Based on Simplified 3DSVM Algorithm

In this paper, a simplified three dimensional space vector modulation algorithm is proposed to control a three-level four-leg DSTATCOM connected to four wire distribution system. The control strategy is carried out for neural current regulation using the fourth leg of the DSTATCOM inverter and for reactive power compensation needed by the load in order to regulate the voltage at the PCC bus under different cases of balanced and unbalanced loads. The DC-capacitor voltages balancing strategy is achieved using the effective use of the redundant switching states of the inverter voltage vectors with no requirements for additional control actions or auxiliary devices. Finally, some simulations results are presented and discussed in order to verify the feasibility and effectiveness of the adopted technique under various loads conditions.