Asymmetrical cascaded multilevel inverter with single DC source using high frequency resonant converter

Abstract

An alternative implementation of asymmetric cascaded H-bridge (ACHB) inverter is presented in this work. The presented ACHB inverter is using a single DC source. The main bridge is directly connected to the DC source (such as, battery, fuel cell or photovoltaic array). And the auxiliary bridges are fed by isolated series resonant converter (SRC). Voltage of the auxiliary bridge is balanced by controlling the switches of SRC. The SRC is operated in lagging p.f. mode to reduce switching losses. A simple controller has been used to control the SRC converter. The proposed topology is simulated in Matlab/Simulink environment to verify the performance of the system.