永磁同步电机谐波电压与电流的耦合模型及前馈控制

以一组正负序谐波电流对为研究对象,构建了多同步旋转坐标系下永磁同步电机的谐波电压模型,该模型揭示了正负序谐波电压与谐波电流之间的耦合关系。通过在传统矢量控制系统上增加参考谐波电流计算模块与前馈谐波电压计算模块,构建一种谐波电流注入控制系统,该系统中电流比例积分(PI)控制器只需完成基波电流对应直流量的跟踪,谐波电流的跟踪性能则由前馈的谐波电压保证。选取两种永磁同步电机作为谐波电流注入的试验对象,对比具有前馈谐波电压的系统与仅包含电流PI控制器的系统的谐波电流响应结果,台架试验结果表明前馈谐波电压能够有效地改善高频谐波电流注入的效果,另外从时域及频域分别对电机输出的转矩脉动信号进行对比和分析,结果表明:利用前馈谐波电压能更准确地完成谐波电流的注入,进而实现永磁同步电机转矩脉动的有效抑制。

A Harmonic Voltage and Current Coupling Permanent Magnet Synchronous Motor Model and Feedforward Control

This paper introduced a harmonic voltage model of permanent magnet synchronous motor (PMSM) on multiple rotating synchronous coordinates, considering one couple of positive and negative sequence harmonic current simultaneously. The model revealed the coupling relationship between positive harmonic voltage and negative harmonic current. By adding reference harmonic current computing module and feedforward harmonic voltage computing module to the traditional vector control system, a novel harmonic current injection system was established. In that system, the PI current controller only needed to track the direct component gain, while the gain of harmonic component was guaranteed by the feedforward harmonic voltage. Finally, two kinds of PMSM were selected as experiment objects of harmonic current injection. The results of harmonic current response from traditional PI current controller and the proposed harmonic current injection system were compared, which represented that feedforward harmonic voltage can improve the injection effect of high frequency harmonic current. In addition, the corresponding torque signals were also compared and analyzed in time and frequency domains. It illustrated that the harmonic current can be injected more precisely with feedforward harmonic voltage, thereby the torque ripple of PMSM can be reduced effectively.