永磁同步电机用坐标变换的电流谐波抑制方法

Permanent magnet synchronous motor current harmonics suppression based on coordinate transformation

针对永磁同步电机在运行过程中电流波形发生畸变、谐波含量高等问题,结合同步旋转坐标变换理论提出一种谐波抑制方法。建立永磁同步电机的数学模型,分析时间谐波和空间谐波的产生原因及对电机正常运行造成的不利影响。采用坐标变化与低通滤波器检测5次与7次谐波,在原有的双闭环系统基础上增加谐波电流环,通过PI控制抑制谐波电流。最后以4k W表贴式磁悬浮永磁同步电动机为对象进行仿真分析和实验验证,仿真和实验的结果表明,采用坐标变换的谐波抑制算法可以有效抑制谐波电流,提高电机相电流的正弦度,对不同原因造成的谐波均有抑制作用,并且具有计算简单、容易实现的特点。

The current of permanent magnet synchronous motor （ PMSM） contains a lot of harmonic cur-rents, resulting in the motor current waveform distortion. In order to solve this problem, a novel suppres-sion method based on synchronous rotating coordinate transformation was proposed. Based on the estab-lished model of PMSM, the adverse impact caused by harmonics was analyzed. Through rotating coordi-nate transformation and low-pass filter, the fifth and seventh harmonic currents were extracted and con-trolled by PI regulator. Simulations and experiments with a 4-kW magnetic suspension PMSM were car-ried out. The results verify that the method based on coordinate transformation can suppress the harmonic currents caused by different reasons. The proposed method has the advantage of easy mathematical com-putation and simple implementation.