A novel cascaded two transistor H-bridge multilevel voltage source converter topology

Abstract

In this paper a novel multilevel voltage source inverter topology is proposed for high power applications requiring expensive switching component such as, traditional Silicon, and/or newly-evolving Silicon Carbide, and/or Gallium Nitride based power semiconductor transistors. This multilevel voltage source inverter consists of several series connected newly developed single phase two transistor H-Bridge inverters with separate DC sources in accordance with the required output voltage level. The topology achieves a major reduction in expensive power semiconductor transistors, which can be accomplished without compromising its performance. For example, the 5-level three phase proposed inverter employs only 12 power transistors as opposed to 24 power transistors of a functionally equivalent conventional cascaded multilevel voltage source inverter. The proposed m-level topology is analyzed theoretically in this paper with the simulation results of the 5-level topology to verify the characteristics, performance, and feasibility.