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定子绕组星形结点相隔离的双Y移30°六相电机与PWM变流器组成的系统会产生共模电压,给系统带来不利影响.为了抑制共模电压的大小与变化频率,分析了六相电压空间矢量的共模电压特点,提出一种六相SVPWM方法.该方法从64个基本矢量中选择共模电压不产生变化的非零基本矢量进行线性组合,得到一组中间矢量,使中间矢量在o1o2和z1z2平面为零矢量;然后利用中间矢量去合成dq平面上的期望矢量,合成过程中不使用dq平面上的零矢量.仿真和实验结果表明,在保持定子谐波电流抑制效果良好、电机转矩和转速动稳态性能良好的情况下,共模电压峰峰值为变流器直流母线电压的1/3,变化频率仅为线电压基波频率的3倍,远低于变流器开关频率.该方法可进一步拓展,用于抑制多相电机系统的共模电压大小与变化频率.“,”There is common-mode voltage (CMV) in a system composed of dual Y shift 30° six-phase electric machine with separate star points of stator winding and PWM converter, which brings detrimental effects on the system. To suppress the amplitude and changing frequency of CMV, a new method of space vector pulse width modulation (SVPWM) was presented, with characteristic of CMV analyzed. The intermediate vectors were structured by linearly combining the non-zero basic vectors without variation of CMV from 64 basic vectors, which become zero vectors in theo1o2 andz1z2 planes. The expected vector in thedq plane was synthesized by intermediate vectors without zero vectors. Simulation and experimental results show that the peak-to-peak value of CMV is one third of converter DC-bus voltage, and the changing frequency of CMV is only three times of the line voltage fundamental frequency, which is much less than the converter switching frequency under such condition as the harmonic current of stator winding is effectively restrained, the motor is good in steady and dynamic performance of torque and speed. The proposed method can be further extended to multi-phase electric machine system.