Five-Level Cascaded Flying-Capacitor Converter

Abstract:
A new five-level converter is developed based on the principle of the three-level Flying-Capacitor converter. When extending existing three-level converters to a higher number of voltage levels the topology becomes more complex. Commutation circuits are created that consist of several power semiconductors as well as capacitors. Nevertheless these commutation circuits have to be as low inductive as possible causing high complexity of the bus bar. The proposed new five-level converter is divided into three partial converters using conventional Flying-Capacitor converters, which have already a low-inductive bus bar. Furthermore, there is no need for a low-inductive connection between the partial converter, which reduces the complexity.