Abstract: Aiming at the problem in accuracy of PMSM speed control system and position tracking that caused by the traditional high frequency signal injection method, an improved pulse vibration of high frequency injection method based on wavelet transform filter is proposed, which injects low amplitude and high frequency voltage signal in the d-axis. The multi-scale frequency band decomposition of the q-axis current signals containing the position information is carried out by using the db4 wavelet packet, the wavelet packet coefficient threshold is determined by the maximum and minimum criterion, and the position signal is effectively extracted by using the soft threshold selection method to reconstruct the decomposition factor of the wavelet packet. It can solve the problem of insufficient precision when extracting the low amplitude weak signal by the traditional Butterworth filter. The simulation results show that the proposed method can effectively eliminate the noise signal and extract position information. This method can ensure the accuracy of position tracking and greatly reduce the torque pulse vibration.

Key words: High-frequency signal injection, torque ripple, wavelet filter, position tracking 

摘要： 针对传统高频信号注入法引起PMSM调速系统振动和位置跟踪精度不足等问题，提出了一种基于小波变换滤波的改进脉振高频注入法，该方法在d轴注入低幅高频电压信号，利用db 4小波包对包含位置信息的q轴电流信号进行多尺度频带分解，以最大最小准则确定小波包系数阈值，并采用软阈值选取方法重构小波包的分解系数，有效提取位置信号，解决了传统的巴特沃斯滤波器无法提取低幅弱信号或提取精度不足的问题。仿真表明该方法有效地实现了信号去噪和位置信息提取，保证了位置跟踪精度，且大大降低了系统转矩脉振。

关键词: 高频信号注入, 转矩振动, 小波滤波, 位置跟踪