Analysis and comparison of hybrid multilevel voltage source inverters

Abstract

This paper analyzes different hybrid multilevel inverters for high-power applications. With these hybrid topologies, it is possible to minimize the number of series-connected inverters for a given number of levels and, consequently, to reduce the THD of output voltage. Moreover, this paper develops a comparison among different hybrid multilevel inverters, especially between binary and trinary hybrid multilevel inverters. Several points are discussed, taking into account number of levels, spectral performance and power processing of hybrid multilevel inverters. Finally, a design procedure to obtain the number of H-bridge cells and DC voltage source of each cell for a given number of levels is proposed, so that few H-bridge cells synthesize a voltage waveform with a large number of levels, in order to minimize the circulating energy among cells.