New cascaded multilevel inverter topology with reduced variety of magnitudes of dc voltage sources

Abstract

In this paper, a new basic topology is proposed for cascaded multilevel inverters. The proposed basic topology is comprised of two dc voltage sources, two unidirectional power switches, and an H-bridge. A new generation of cascaded multilevel inverters can be achieved by series connection of some number of proposed basic topology. The proposed cascaded multilevel inverter in symmetric condition utilizes less number of switches in comparison with the conventional symmetric multilevel inverter. In addition, in asymmetric condition, the variety of magnitudes of dc voltages sources is less than the conventional ones. In order to generate all voltage levels (odd and even), four new algorithms are suggested to determine the magnitudes of dc voltage sources. The ability of the proposed topology in generating the desired output voltage is proved through the simulations results carried out in PSCAD/EMTDC software.