Analysis of two single phase DC-AC multi-level converters with multiple DC sources

The main objective of this paper is to analyze two different types of nine level inverters. This paper depends on the multilevel converters with multiple numbers of DC sources and presents cascaded H-bridge nine level inverter and multi string nine level inverter topologies with four input DC sources. The purpose of this paper is to show the differences between these two converters in terms of modulation scheme, switching losses. These comparisons were never made between cascaded H-bridge multi-level converter (CHBMC) and multi string multi-level inverter (MMC). The modulation schemes and the determination of unipolar PWM modulation signals of these two converters are discussed. The switching losses between these two converters are also discussed. Simulation and experimental results of the two converters validate the proposed analysis.