Detent Force Fast Optimization Method of Modular Permanent-Magnet Linear Synchronous Motors

This article investigates the detent force optimization of a modular permanent-magnet linear synchronous motor (MPMLSM). First, the topology structure of a 6-slot/5-pole MPMLSM is introduced, which primary consists of eight modules. Second, the detent force harmonics feature is analyzed including its two components, cogging force and end force. Third, the effects of decoupling optimized method of optimized cogging force and detent force separately and the modulation optimized method of directly optimized detent force are investigated. Combining the modulation method and skewed permanent magnets, a flow chart of fast optimization is proposed for detent force reduction. Fourth, the MPMLSM is optimized by the proposed method, which second harmonic of the detent force has been reduced to 0.41 N, and the peak-to-peak value of the detent force is optimized to 0.94 N. Finally, a prototype is made and tested. The experimental results verify the effectiveness of the proposed fast optimization method, which is applicable to PMLSM with any close slot-pole combination.