A new control method for single-dc-source cascaded H-bridge multilevel converters using phase-shift modulation

Multilevel converters have gained popularity in high-power applications due to their low switch voltage stress and modularity. Cascaded H-bridge converters are a promising breed of multilevel converters, which generally require several independent dc sources. Using phase-shift modulation, a new control method for cascaded H-bridge multilevel converters with only one independent dc source per phase is presented in this paper. Unlike the conventional approaches, the proposed method has a wide voltage regulation range over the capacitors replacing the dc sources in the H-bridge converter cells.