Predictive control of a cascade asymmetric multilevel converter with split redundant states

Abstract

This work presents a control strategy for the cascade asymmetric multilevel converter (CAMC). The analysis of the switching states of the topology is perfomed. A new voltage ratio for the phase capacitor, which splits redundant states and expands the number of levels from five to seven, is proposed. This improves the harmonic profile of the output voltage without additional switching devices. A Finite-states model predictive controller (FS-MPC) that uses simple dynamic models, jointly with properly defined cost functions performs the regulation of the internal voltages of the converter (phase capacitors and DC bus capacitors) and the line currents of a three phase load.