CHEN Rong, FAN Cheng zhi, LI Wan wan

 

(College of Electrical Engineering, ZheJiang University, Hangzhou 310027, China)

 

 

Abstract: Aiming at the problem of vibration and noise caused by harmonic wave in air gap,two kinds of interior permanent magnet rotor structure were discussed. FEM method was introduced to study the influence of magnetic bridge and magnet size on the noload air gap field. New structure with divided sections was proposed. Different length of interval in ‘一’ shaped structure and angle in “V” shaped structure were analyzed to study the effect on air gap and harmonic distortion. Results show airgap waveform becomes more sinusoidal when the bridge gets thinner, which helps to reduce vibration and noise. And airgap waveform performs better with bigger angle in “V” shaped structure. “V” shaped structure has higher mechanical strength and salient rate, but its airgap gets worse and magnet utilization rate decreases.

 

Key words: magnetic property; total harmonic distortion (THD); harmonic distartion rate rotor topology