Double-Symmetrical-Voltage Placement PWM Method for Phase Voltage Controlled Open-End Winding PMSM Drives

The zero-sequence current (ZSC) in the zero-sequence loop (ZSL), which is inherent in open-end winding permanent magnet synchronous machine (OW-PMSM) drives with a common dc bus, increases the torque ripple and the system loss. The simultaneous control of dual inverters and the ZSL complicates the pulse width modulation (PWM) method. This article proposes a double-symmetrical-voltage placement PWM (DSVP-PWM) method based on phase-voltage-independent control. This method significantly reduces the calculation time of the modulation and achieves the equivalent effect of the traditional space vector pulse width modulation (SVPWM). Furthermore, the effect of different voltage placements on the current ripple is discussed. Compared to the traditional SVPWM method, the proposed DSVP-PWM method leverages the characteristic of phase-voltage-independent control in OW machines and demonstrates enhanced universality for various OW machines. Finally, the effectiveness of the proposed method is verified experimentally.