Suppression of common mode circulating current for modular paralleled three-phase converters based on interleaved carrier phase-shift PWM

摘要

Circulating current has been the major concern for the implementing of paralleled converters. Extensive studies have been conducted in reducing the circulating current with different modulation strategies. However existing methods are either suffering from poor performances or too complicated for implementation. This paper proposes an interleaved carrier phase-shift (ICPS) PWM to reduce the peak value of the high frequency common mode circulating current (HF-CMCC). The proposed method can be used in the system with arbitrary number of VSCs, which makes the method very suitable for modular design. In addition, the ICPS PWM is very simple for implementation. Theoretical analysis is presented in this paper to explain the effectiveness of ICPS PWM on CMCC peak value reduction. The proposed method has been verified and compared with the interleaved SPWM (ISPWM) in simulation and experiment.