Systematic Derivation of Simplified Active-Neutral-Point-Clamped Multilevel Converter through Matrix Models

With the increase of voltage levels, active-neutral-point-clamped (ANPC) multilevel topology can be dramatically complex and consists of a high number of switching devices. Therefore, simplification of ANPC topology is favored by both manufacturers and customers, as the device costs, control complexity, and maintenance burden, can be reduced. However, due to the complicated topological structure of ANPC topology, systematic simplification method is not available in the literature. This paper proposes a general systematic simplification approach for multilevel ANPC converter through matrix representation of multilevel converter. Based on the proposed approach, different PWM patterns can be carried out and then be implemented directly for simplified topologies. To demonstrate the proposed method, several examples are given, where several simplified ANPC topologies are developed and analyzed. Experimental results are provided to validate the feasibility of these derived topologies.