A Fast Prediction Method for Thrust Performance of Axial Array Permanent Magnet Synchronous Linear Motor

Abstract

This paper presents an improved subdomain model for predicting the open-circuit magnetic field of a permanent magnet synchronous linear motor (PMSLM), taking into consideration the axial array and primary end effects. The improved subdomain model involves treating the permanent magnet as a secondary core with infinite permeability covered by a current layer in lieu of the actual magnetic source, which is then solved using the equivalent magnetic circuit method. Additionally, the model employs coordinate transformation (i.e., converting from a Cartesian coordinate system to a polar coordinate system) to establish a subdomain model in the polar coordinate system. This approach significantly reduces the number of subdomain division regions and effectively alleviates programming and computational complexities compared to conventional subdomain models. The accuracy of the analysis results is confirmed through finite element method validation. The findings demonstrate that the proposed improved subdomain model significantly enhances computational efficiency without sacrificing accuracy. By applying the proposed method, the motor structure is also improved. Specifically, compared to the structure before improvement, the end force of the motor decreases by 42.41%, while the rated thrust increases by 38.59%. These improvements contribute to an overall enhancement in motor performance.

Keywords

• Linear motor
• equivalent magnetic circuit
• subdomain model
• magnetic field
• end effect