A Novel Voltage-Balancing Control Strategy for CHBR Based on Feedback of the Energy Stored in Capacitor

Abstract

Aiming at the problem of DC capacitor voltage imbalance in cascade H-bridge rectifier under the condition of unit power factor, the paper proposes a novel voltage-balancing control strategy based on feedback of the energy stored in capacitor. Compared with the traditional method, the proposed method enhanced the the system anti-interference preformance to load variation. Specifically, the mathematical model of the CHBR in the d-q coordinate frame is introduced. Then, The mathematical expression of capacitor energy and duty cycle compensation of each H-bridge is established, and the detailed implementation of the proposed strategy is given in this paper. Finally, the correctness and effectiveness of the proposed strategy are verified by simulation.