Hybrid PWM Scheme for Common-Mode Voltage Reduction in Asymmetrical DC-Link Voltages Dual-Inverter OEW-PMSM Drives

Hybrid PWM methods have been demonstrated as effective solutions for common-mode voltage reduction in dual-inverter systems with equal DC-link voltages. This paper investigates hybrid PWM strategies applicable in a DC source-fed high-voltage inverter and battery-fed low-voltage inverter in dual-inverter open-end winding PMSM drives, focusing on common-mode voltage mitigation. A novel PWM method is proposed to achieve effective CMV reduction under high modulation index. The effectiveness of the proposed method is validated through MATLAB/Simulink simulations, with comparative analysis against conventional hybrid PWM methods. Results indicate that the proposed PWM methods maintains comparable CMV suppression capability while simultaneously reducing switching count and optimizing battery energy utilization.