Zero-Sequence Current Suppression Strategy for Five-Phase OW-PMSM With Reduced Common-Mode Voltage and Inverter Losses

Zero-sequence current (ZSC) exists in five-phase open-winding permanent magnet synchronous motors (FPOW-PMSMs) with a common dc bus, resulting in harmonic current and system losses. Besides, the use of the dual-inverter increases inverter losses and induces a high-frequency common-mode voltage (CMV), damaging the bearing. This article proposes a novel ZSC suppression method for the FPOW-PMSM, which can reduce the inverter losses while decreasing the CMV. First, the average zero-sequence voltage equal to zero is considered a restriction to calculate the duration time of basis vectors. Five active vectors are selected to synthesize the reference voltage vector in each sector. Then, benefiting from abundant switching states redundancy, a novel switching states combination with minimum switching actions is proposed to reduce the CMV and inverter losses. Furthermore, the modulation range of the proposed modulation method is analyzed, indicating that the proposed method achieves considerable dc-bus voltage utilization. Finally, the experimental results verify the effectiveness of the proposed method.