传统的三相电机空间矢量控制方法会引起很大的，频率很高共模电压，本程序采用相对矢量合成零矢量，降低了共模电压的幅值和频率(The traditional space vector control method of three-phase motor will cause great common-mode voltage with high frequency. This program uses relative vector to synthesize zero-vector, which