Novel space vector-based PWM strategy with minimal circulating current and line-current ripple for two parallel interleaved inverters

Abstract

Existing PWM methods suffer from a tradeoff between zero-sequence circulating current (ZSCC) and line-current ripple, which are two major concerns of two parallel interleaved two-level (2L) voltage-source converters (VSCs). Thus, this paper introduces a novel space vector-based PWM strategy to reduce both line-current ripple and ZSCC. Given the redundancy of the vector combination of two parallel interleaved converters, this paper proposes eight optimal vector sequences, which simultaneously optimizes the ZSCC and the line-current ripple. Then, a carrier-based scheme is applied to yield optimal vector sequences, which simplifies the implementation procedure. Furthermore, this paper quantitatively compares both the ZSCC and the line-current ripple of the proposed method to those of existing PWM schemes. This comparison confirms that the proposed method is superior to existing PWM schemes in terms of current ripple and ZSCC. Finally, experimental results further verify the theoretical analysis and the effectiveness of the proposed strategy.