China International Youth Conference on Electrical Engineering (CIYCEE 2020)

1726 / 2020-09-29 17:52:02

Optimization of Magnetic Pole Structure of High-speed Permanent Magnet Synchronous Motor Weakens Cogging Torque

PMSM; Permanent magnets; multi-physics and coupling analysis; Air gap magnetic field; Cogging torque

Electric Machine Design and Control > Electric machines

In order to suppress the cogging torque of permanent magnet synchronous motors, a layered permanent magnet structure composed of different permanent magnet materials is proposed. The multiphysics coupling analysis of the electromagnetic field and the temperature field of the permanent magnet motor in ANSYS software was performed to obtain the temperature difference between the stator and the rotor due to air gap wind milling during the motor operation. Based on this, the temperature can be used near the stator layer of the permanent magnet. A low-coefficient magnetic material can effectively reduce the harmonic content of the air gap magnetic flux density of the motor, thereby reducing the cogging torque. Finally, a differential algorithm is used to optimize the thickness of the permanent magnet material on the outer surface to obtain the permanent magnet size parameters that make the motor better. Simulation results show that the layered permanent magnet structure can effectively reduce the cogging torque of the permanent magnet motor and effectively improve the sine of the back-EMF waveform after optimized design.