Common Mode Voltage Reduction Algorithm of Triple Three-Phase Motors Based on Phase Shift

Multi-phase motors have been widely studied and applied in low-voltage and high-power applications. However, under pulse width modulation (PWM), the system inevitably generates common-mode voltage (CMV), which will harm the system. In particular, the odd set of three-phase motors cannot eliminate the CMV because of its odd bridge arms. In this paper, a common-mode voltage reduction (CMVR) algorithm based on triple three-phase motors (TTPM) is proposed. Through proper zero-sequence voltage injection and pulse phase shifting, the amplitude reduction and constant amplitude control of CMV can be achieved under different maximum modulation ratios. The algorithm can effectively reduce the common mode (CM) electromagnetic interference (EMI) of the system, and the algorithm can be easily realized by carrier-based pulse width modulation (CBPWM). Finally, the simulation results show that the proposed algorithm is effective for reducing the common mode voltage of triple three-phase motors.