Simplified hybrid nine-level stacked multiceli converter with reduced part count for grid-connected applications

Abstract

Increasing demand for high-efficiency inverters with improved output waveform quality has enhanced the research in the area of multilevel inverters (MLIs). A dc-ac hybrid inverter formed by cascading a five-level (5L) stacked multicell converter (SMC) and floating capacitor (FC) H-bridge is proposed. It requires only 12 switches and three FCs for nine-level (9L) operation. The most important advantage of the proposed inverter lies in the fact that it requires minimum topological alteration for extending 5L SMC to 9L. FC voltage control strategy and results confirming the effectiveness and operability of the proposed inverter is presented.