Analysis and Reduction of Detent Force in Flat Permanent Magnet Linear Motor with Inner-Arc Auxiliary Teeth

This paper presents an improved flat permanent magnet linear motor (FPMLM) structure with inner-arc auxiliary teeth to reduce detent force. The parameters that affect detent force are determined by using Fourier analysis method. The influences of slot opening, the side slot widths and the size of end teeth on detent force are investigated, the optimal dimension parameters are obtained by Differential Evolution (DE) algorithm. For verifying the advantages of the improved structure, two FPMLMs with traditional and improved structures are analyzed using finite-element method (FEM), the analytical analysis is verified by extensive 3-D numerical computations. The results show that the proposed structure can significantly reduce the detent force with the least sacrifice of electromagnetic performance.