Adaptive dc-link voltage regulation for DSTATCOM under load variations

Abstract

A new algorithm is proposed for adaptive dc-link voltage regulation in DSTATCOM for power quality improve ment. Generally, in conventional DSTATCOM operation, the dc link voltage is maintained constant by PI controller (i.e, 2 times peak of PCC voltage). Because of fixed voltage, the switches of Voltage Source Inverter (VSI) are subjected to high voltage stresses during off-peak load conditions. It leads to increase in switching losses and deterioration of inverter reliability. During off-peak load, lesser value of dc-link voltage is sufficient to improve power quality. The proposed algorithm will give the reference dc-link voltage corresponding to load rating, and it is computed based on filter burden. The advantage of proposed algorithm is switching stresses reduced. The proposed algorithm is validated through detailed simulation studies.