EVS 28 KINTEX , Korea , May 3-6 , 2015 Cogging Torque Reduction in Surface-mounted Permanent Magnet Synchronous Motor by Axial Pole Pairing

In many machines, where permanent magnets are used, the effects due to cogging torque generated by permanent magnets (PMs) aggravate the output characteristics of the machines. This paper presents the method for reducing cogging torque in surface-mounted permanent magnet synchronous motor (SPMSM). A new cogging torque suppression method called axial pole pairing is proposed. Compared to conventional pole pairing, axial stack length is considered. Analytical formulas are used to estimate cogging torque and verify the validity of axial pole pairing. Characteristics of cogging torque are investigated on various combinations of axial pole pairing. From this result, improvement on space harmonic analysis has been researched about SPMSM for reducing cogging torque.

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