Influence of pole-arc width on cogging torque in permanent magnet motors

This work investigates the effect of the pole-arc width on the cogging torque of the permanent magnet motors based on the assumption of distributed force instead of the previous concentrated one. On the basis of the motors´ mechanical and electrical symmetry, the superposition method is employed to examine the above effect. And the phase tuning relationships between the pole-arc width and the cogging torque is obtained. This study presents a tuning method for the prediction and suppression of the magnetically induced vibration, which in turn provides a theoretical foundation for the dynamic design of the permanent magnet motors. The theoretical conclusions are verified by the Finite Element method.