Influence of Stator Auxiliary Slot on Slot Torque of External Rotor Permanent Magnet Synchronous Motor

In view of the high tooth groove torque of permanent magnet synchronous motor will cause vibration and noise, which will affect the control of the motor, this paper adopts the stator auxiliary groove method to weaken the tooth groove torque. Firstly, the theoretical analysis of the groove torque is carried out. Secondly, based on the finite element simulation software, a 32-pole 36-slot external rotor PMSM model is established. The groove shape of the stator auxiliary groove and the influence of the number of slots on the groove torque are studied, and the optimal shape and number are determined. Thirdly, based on the response surface method, the groove depth and groove width are analyzed by two variables. Finally, the properties of the permanent magnet synchronous motor, such as air gap density and back electromotive force, are compared. The results show that when the stator has a rectangular slot, the slot depth is 2mm and the slot width is 2.4mm, the torque of the slot is the best, which is about 61.7% less than that without the slot. It can effectively reduce the tooth groove torque of permanent magnet synchronous motor.