Structural design of a five-level hybrid active NPC converter for high power density motor drives

Two different power circuit structures have been proposed for a five-level hybrid active neutral-point-clamped (5L HANPC) converters. In order to reduce the size/weight of the converter system, PCB-mounted film capacitors were selected as DC-link banks. The two arrangement of the existing power semiconductor modules are compared in this paper. The comparison includes dimension, weight, parasitic parameters, etc. Finite element models integrating multi-layer PCB and laminated copper bus-bar have been developed to evaluate the current ripple absorption and current sharing in the parallel-connected film capacitors. Simulation results demonstrate that the second power circuit structure are more suitable for high density applications in industry.