A multilevel converter topology with common flying capacitors

This paper introduces a multilevel converter topology with common flying capacitors shared by phases. The unique feature of this configuration makes contribution to reduce the total number of components like switching devices and capacitors, which is closely related to the converter cost and volume. Therefore, low cost and high power density are expected to be achieved. A three-phase 5-level converter, regarded as the minimum system of proposed topology, is analyzed for operational principle explanation and verification. Simulation study and results using MATLAB/Simulink presented in the paper supported the idea and validated the feasibility. In order to implement experimental test, a 200V, 7.5kW mini-model with induction motor load was built up and the results shown are consistent with analysis and simulation.