Common-mode voltage suppression method for permanent magnet synchronous motor

The invention provides a common-mode voltage suppression method for a permanent magnet synchronous motor, which comprises the following steps of: adding a bridge arm in parallel on the basis of a three-phase three-bridge arm inverter, judging a sector in which a reference voltage vector is located, selecting a switch vector, and confirming the action sequence and action time of the switch vector, so as to control the on-off state of the four bridge arms. The six switching vectors u1 (1001), u2 (1100), u3 (0101), u4 (0110), u5 (0011) and u6 (1010) are selected to control the switching state of each bridge arm, so that the use of a zero vector can be avoided, and the common-mode voltage of the system can be reduced to the greatest extent, thereby improving the performance of the motor and prolonging the service life of the motor. 本发明提供一种永磁同步电机共模电压抑制方法，在三相三桥臂逆变器的基础上并列增设一个桥臂，判断参考电压矢量所在扇区、选择开关矢量、确认所述开关矢量的作用顺序及作用时间，从而控制四个所述桥臂的开关状态。本发明选取的六个开关矢量u1(1001)、u2(1100)、u3(0101)、u4(0110)、u5(0011)和u6(1010)来控制各桥臂的开关状态，既可以避免使用零