Analysis of Air Gap Harmonic Magnetic Field and Electromagnetic Vibration of a Permanent Magnet Motor

Electromagnetic vibration is produced by radical exciting force waves acting on iron cores of permanent magnet motors. In order to reduce radial electromagnetic force, a surface mounted permanent magnet synchronous motor was analyzed. According to the electromagnetic force wave of analytical formula in the case of no-load, the main force wave order and force wave frequency were analyzed. Properly selecting the pole arc coefficient could reduce the amplitude of electromagnetic force. By finite element analysis, the results show that reduce the sinusoidal distortion rate of the flux density, electromagnetic vibration of the motor can be reduced to some extent, but not the best choice.