Influence of Stator Core Seams on No-Load Performance of Module-Combined Stator Permanent Magnet Motor and Its Weakening Method

In this paper, a module-combined stator is proposed, which is used for large and ultra-low-speed permanent magnet synchronous motors, and the influence of stator core seams on the no-load performance is studied. A method is proposed to weaken the negative influence of stator iron core seams on the no-load performance of permanent magnet synchronous motors. Firstly, the magnetic circuit model of the motor considering the stator iron core seams was deduced theoretically, and the selection principle of stator core seam number was given a description. The influence of different seam parameters on the no-load performance and the influence of different pole-slot fits and the number of parallel branches on the no-load performance are analyzed. The proposed structure of the stator iron core, which can weaken the influence of stator iron core seams on the no-load performance of the motor, is proposed. Using analysis and simulation experiments, the effectiveness of the proposed stator iron core structures in weakening the negative influence of the stator iron core seams on the no-load performance was verified.