A generalized structure of multilevel power converter

Multilevel inverters are becoming popular in the past few years for high voltage and high power applications. Various topologies and modulation strategies have been investigated for utility and drive applications in the recent literature. However, most of the reported topologies for multilevel structures employ DC voltage sources of equal magnitudes. This paper is devoted to the investigation of a generalized structure of multilevel power converter where these discrete voltage sources are not necessarily equal. The topological structures, operating principles and performance characteristics resulting from this general approach are presented. Various design criteria and issues like spectral structure are discussed. A comparative evaluation of various alternatives obtained from the generalized structure is presented.