Due to machining errors and the effect of the longitudinal end of a stator, linear permanent magnet motors (LPMMs) produce asymmetric three-phase winding resistance and inductance. After a Park transformation of the asymmetric three-phase stator inductance, the dq axis inductance is not constant, and the dq axis is coupled. This leads to errors in estimating the motor position by the traditional pulse injection method. In this paper, the position estimation error caused by parameter asymmetry is analyzed to discuss the influence of LPMM asymmetric three-phase winding parameters on high frequency pulse injection sensorless method error. Moreover, a double stage filtering method is used to realize error compensation. On this basis, a simulation model was built by MATLAB/Simulink and experiments were carried out on a LPMM prototype under no-load conditions. The simulation and experimental results verify that the double stage filtering method can improve the position estimated accuracy and dynamic performance under sensorless control.

由于加工误差和定子纵向端部的影响，线性永磁电机 (LPMM) 会产生不对称的三相绕组电阻和电感。非对称三相定子电感经过 Park 变换后，dq轴电感不恒定，dq轴耦合。这导致传统脉冲注入方法估计电机位置时出现错误。本文通过分析参数不对称引起的位置估计误差，讨论LPMM不对称三相绕组参数对高频脉冲注入无传感器法误差的影响。此外，采用双级滤波方法实现误差补偿。在此基础上，利用MATLAB/Simulink建立了仿真模型，并在LPMM样机上进行了空载条件下的实验。仿真和实验结果验证了双级滤波方法可以提高无传感器控制下的位置估计精度和动态性能。