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

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.