A Unified Method for Suppressing Both Zero-Sequence and Intraphase Circulating Currents in Two-Parallel Three-Phase Power Converters

This paper proposes a unified PWM strategy for sup-pressing both intra-phase and zero-sequence circulating currents in two-parallel converters. The presented analytical modeling re-veals that certain vector combinations inherently enable simulta-neous control of both intra-phase and zero-sequence circulating currents. Then, ten candidate vector sequences are constructed us-ing those vector combinations. Since these vector sequences exhibit redundancy in the modulation region, we select the one with the lowest circulating current peak and RMS value. Subsequently, we develop a flowchart to implement the optimal vector sequences across the entire space vector plane. Quantitative comparisons with state-of-the-art PWM methods demonstrate that the pro-posed method not only reduces intra-phase current but also achieves lower zero-sequence circulating current. Experimental validation confirms the effectiveness of the proposed method in suppressing both types of circulating currents.