Compensating the island network voltage unsymmetricity with DTC-modulation-based power conditioning system

An algorithm for compensating island network voltage unsymmetricity with a direct torque control modulation-based scalar-controlled power conditioning system is introduced and experimentally verified. The proposed method consists of two separate stages where at first the unsymmetricity is detected and then a compensating negative-sequence system is calculated. Experimental results show that the proposed method fully compensates the voltage unsymmetricity resulting from unbalanced load. Both the magnitude and the phase angle unsymmetricity are compensated. Index Terms--DC-AC power conversion, power converters, unbalanced load.