Thrust ripple reduction based on auxiliary-slot permanent magnet synchronous linear motors

Permanent magnet synchronous linear motor (PMSLM) has the advantages of simple mechanical structure and high thrust density. However, the simultaneous existence of end effect and cogging force aggravates the thrust ripple and affects the output characteristics of PMSLM. This paper proposes various rectangle and easily machinable auxiliary slots for core teeth to reduce thrust ripple. Firstly, the length, width and position of the auxiliary slot are parameterized by the finite element method, and the minimum detent force is solved to obtain the optimal slot size. Then, taking the air-gap flux density harmonic, average thrust and thrust ripple as reference indexes, the performance differences of the three auxiliary slots are compared. The results show that the auxiliary slot on the side of the tooth can reduce the thrust ripple by up to 22.4%, and the average thrust is only reduced by 3.7%. Finally, the correctness of the numerical simulation is verified by experiments.