A Novel Method of Reducing the Cogging Torque in SPM Machine with Segmented Stator

Abstract

-The method of stator segmentation is generally taken to enhance the electromagnetic performance of surface-mounted permanent magnet (SPM) machine and reduce its production cost. Based on the model with single slot, the expressions of cogging torque in machine with uniform or non-uniform segmentations are deduced and the optimal combination is given. Moreover, this paper discusses a structured skewing method and put forward a novel stator structure model to reduce the cogging torque in segmented permanent magnet machine. The model can reduce the cogging torque amplitude by shifting a proper angle of slot-opening. The shifting angle formula for analysis can also be suitable for other permanent machine with segmented stator. Finally the results of finite element simulation are given to prove that the method is effective and feasible.

Electromagnetic and thermal analysis and design of a novel‐structured surface‐mounted permanent magnet motor with high‐power‐density

“…To increase the power density of such a motor, the segmentedcore (SC) structure, which not only increases the coil space factor but also decreases the cogging torque and torque ripple by reducing the slot opening, has become commonly used [5][6][7][8][9][10][11]. However, the conventional SC motor, the most widely used type for robots, has the problems such as increases in the cost, decrease in yields, and declines in performance capabilities given the complexity of both the structure and the manufacturing processes [12][13][14][15][16]. To address these problems, a motor with a novel structure is proposed for robots.…”