A new cascaded multilevel inverter with series and parallel connection ability of DC voltage sources

Abstract

In this paper, a new multilevel inverter is proposed based on the connection of DC voltage sources in series and parallel. The proposed topology is composed of series basic units that consist of series and parallel connections of DC voltage sources. The values of the DC voltage sources differ from one unit to another. A new algorithm to determine the magnitude of the DC voltage sources of the proposed structure is presented. All of the related equations for the proposed multilevel inverter are extracted and the optimum structure from several points of view such as the maximum blocked voltage by switches, the number of switches and that of the DC voltage sources is obtained in order to have the maximum voltage levels at the output. The proposed topology is compared with that of some of the multilevel inverters presented recently. Finally, the proposed structure and capabilities are reconfirmed using simulation and experimental results for a 53-level typical inverter.