Thrust Ripples Suppression of Permanent Magnet Linear Synchronous Motor

Abstract

The thrust ripples in permanent magnet linear synchronous motor (PMLSM) are mainly generated by the distortion of the stator flux linkage distribution, reluctance force due to the relative position between the mover and stator, cogging force caused by the interaction between the permanent magnet (PM) and the iron core, and the end effects. This is the significant drawback which will deteriorate the performance of the drive system in high-precision applications. Comparing the complexity of the motor structure design to eliminate the thrust ripples, an optimal control method is more desirable. This paper focuses on thrust ripples reduction based on the predictive control algorithm. To minimize the thrust ripples and realize the high-precision control, the components of thrust ripples are extracted by finite element method (FEM) first and then compensated by injecting the instantaneous current to counteract the thrust ripples using the field-oriented control (FOC) method. The effectiveness of this proposed method is verified by the simulation using Simulink/Matlab according to the comparison between the compensation and noncompensation cases