Alternate Subhexagonal Center Dual-Inverter PWM Scheme for Open-End Winding DC-Biased-VRM Drive Using Adjustable Zero Voltage Vector With Dead-Time Effect Compensation

This article proposes an alternate subhexagonal center dual-inverter pulsewidth modulation (PWM) scheme for open-end winding dc-biased vernier reluctance machine (dc-biased-VRM) drive using novel adjustable zero voltage vector to reduce the inverter loss. The alternate subhexagonal center scheme is utilized to assure the regulation of ac voltage, and a novel adjustable zero voltage vector strategy is proposed to reconfigure the zero-sequence voltage and realize the real-time adjustment of zero-sequence current. In addition, the dead-zone distortion of the proposed scheme is analyzed, and a dead-time effect compensation strategy is investigated based on the proposed PWM scheme to suppress the dead-zone distortion. Furthermore, an average zero voltage action time control strategy is associated with the adjustable voltage vector, the maximum linear modulation range is guaranteed when the voltage utilization is close to the limit, so as to improve the machine speed range. Finally, prototype experiments have confirmed the efficacy of the proposed scheme, offering an efficient approach to enhancing the performance and operation range.