Modulated model based predictive control with switcher of redundant states for a three-phase cascade H-bridge multilevel STATCOM

Abstract

Due to problems caused by variable switching frequency a modulated model based predictive control was proposed for different topologies and their applications. However, for cascade H-bridge multilevel converters, there is another problem, the imbalance in the dc-link voltages. This paper proposes extend the modulated model based predictive control to a cascade H-bridge 7-level STATCOM, further including a switcher of redundant states to solve the imbalance voltage issue. Simulation results show improvements in terms of mean squared error, total harmonic distortion and balance voltages in the dc-links.