A novel hybrid five-level voltage source converter based on T-type topology for high-efficiency applications

摘要

A novel hybrid five-level voltage source converter for high-efficiency applications is presented and investigated in this paper, and the topology configuration is based on the upgrade of three-level T-type converter and two-level converter. Compared with traditional stacked multilevel converter and flying capacitor multilevel converter, this hybrid multilevel converter generates desired staircase voltage levels with a reduced number of power devices and isolated drivers. It has nine redundant switching state combinations in hybrid five-level converter, which makes it easy to balance the flying capacitor voltage and realize fault-tolerant operation. A simple control strategy based on phase disposition PWM method is presented for the proposed hybrid converter, in order to generate desired levels while control the flying capacitor voltage. The performance of the hybrid multilevel converter is investigated in MATLAB/Simulink under various operating conditions. The effectiveness of the proposed hybrid multilevel converter is validated by experimental platform.