Segment phase-shifted carrier PWM to reduce common-mode-voltage

In this paper, a segment phase-shifted carrier PWM method is proposed. According to the sector, the modulation wave can be discontinuous with different zero sequence signal injected and the carrier wave are phase shifted, which is different from conventional SVPWM. Using this technique, the peak-to-peak value of the common-mode voltage in one PWM cycle can be reduced to one third of the DC bus voltage at any speed, even despite of the dead-time effect. The good natural over modulation characteristic performance with high voltage utility is also researched. Furthermore, the technique can be generalized to obtain a series of PWM methods. Both theoretical and experimental results are presented to verify the validity of proposed technique.