A nonzero vector PWM method to reduce common-mode voltage

The common-mode voltage (CMV) in voltage source inverter may seriously affect the motor drive system. It can be restrained with proper PWM method if only nonzero space vectors are used. In this paper, a nonzero vector PWM technique (NZPWM) is proposed. Using this method, three odd/even active vectors in low voltage region, or three adjacent active vectors in high voltage region, are used to build the reference voltage vector. So in the entire modulation index range, the peak-to-peak value of CMV can be reduced to one third of the traditional SVPWM, which is the minimum theoretically. Some simulation and experimental results will be presented, which show that the proposed method is effective in CMV reduction.