Cascaded Multilevel Converter based DSTATCOM using p-q theory with DC link voltage balancing

This paper presents the p-q theory based DSTATCOM for reactive power management to control the power factor in a distribution system which serves resistance-reactance loads. Power factor which is one of the measures of power quality in a distribution system plays an important role in the optimal operation of the power system. The active management of reactive power proposed here with p-q theory based DSTATCOM lends itself to remote control of reactive power to improve the operational efficiency of the power system. This study is intended to evaluate the effectiveness of a controller based on the p-q theory coupled with a Cascaded Multilevel Converter (CMC) based DSTATCOM in managing the reactive power in the distribution system. Also as part of this study the ability of the independent P-I controllers to maintain the DC voltages constant across the multi-level H-Bridges of the CMC will be evaluated. The algorithm for the inverter control scheme based on a level shifted multi carrier based sinusoidal pulse width modulation scheme with In-Phase disposition will be tested. Ultimately the performance of the integrated CMC based DSTATCOM for reactive power management will be evaluated.