Reduced Common Mode Voltage PWM Strategy With Optimized Switching Sequence for Three Phase Motor Drives

This paper proposes a pulse width modulation (PWM) switching sequence strategy aimed at minimizing common-mode voltage (CMV) in three-phase motor drive systems. CMV, originating from the charging and discharging of parasitic capacitances, can lead to issues such as electromagnetic interference (EMI) and premature bearing failure. While conventional reduced CMV-PWM (RCMV-PWM) techniques address these problems, they are limited by CMV spikes that diminish their effectiveness. This paper introduces an improved switching sequence that mitigates CMV spikes across all motor operating regions. The proposed method is developed by analyzing CMV variations and identifying the causes of spikes in active zero state PWM (AZSPWM) techniques. Its effectiveness is verified through both simulation and experimental validation against standard space vector PWM (SVPWM) and conventional AZSPWM.