Modular multilevel cascaded converter based on current source H-bridges cells

Modular multilevel cascaded converter emerges as an important alternative in high voltage DC transmission systems, due to its high reliability and power quality. This converter is composed by several identical cells whose are, in turn, composed by a chopper or an H-bridge and a floating DC capacitor. This paper proposes a modular multilevel converter with a novel cell topology based on a current source H-bridge. The use of this cell could improve the input and output power quality and, due to the IGCT current and voltage ratings, reduce the number of cells in series to achieve the required DC voltage and at the same time increase the transmitted power. Analysis and simulation of the proposed topology and its control are given.