基于双同步旋转坐标系的五相永磁同步电动机三次谐波电流抑制方法

Third Harmonic Current Restraining of Five-phase Permanent Magnet Synchronous Motor Based on Dual Synchronous Rotating Coordinates

针对五相电压源逆变器的死区效应及五相永磁同步电动机转子磁场非正弦造成的3次谐波电流,提出了一种基于双同步旋转坐标系的抑制算法。研究了五相电压源逆变器死区效应的作用机理,将死区时间造成的误差电压脉冲序列等效为低频谐波电压。运用扩展对称分量法,得到了五相永磁同步电动机的解耦数学模型。死区效应形成的3次谐波电压以及转子3次谐波磁势作用在阻抗较小的3次谐波子空间会引起很大的3次谐波电流,在3次谐波同步旋转坐标系下增加一对谐波电流控制器以抑制3次谐波电流。在FPGA中实现了所提出的双同步坐标系控制算法,实验结果表明,所提算法可以有效地抑制五相电压源逆变器死区效应以及转子磁势非正弦引起的3次谐波电流。

A dual-plane vector scheme with an additional pair of harmonic current controllers was proposed to restrain harmonic currents caused by dead-time effect of voltage source inverter（VSI） and the dis-sinusoidal EMF of five-phase permanent magnet synchronous motor（FPMSM）.The low-order harmonic voltage generated by dead-time effect was researched.Using extended symmetrical component transformation,the mathematic model under rotating coordinate of FPMSM was deduced.The third harmonic voltage would cause large magnitude of harmonic current for the low impedance of third harmonic sub-space,so an additional pair of harmonic current controllers was introduced to compensate them.The whole arithmetic is implemented in a single FPGA chip,experimental results demonstrate the proposed compensation method can effectively restrain harmonic current generated by dead-time effect of VSI and dis-sinusoidal EMF.