磁极调制式永磁电机的磁场分析与实验

Magnetic Field Analysis and Experiment of Sinusoidal Magnetic Pole Modulation Permanent Magnet Machine

为提高传统表面式永磁电机气隙磁场的正弦程度,降低永磁电机的谐波影响,提高表面式永磁电机的力能指标,提出一种正弦磁极调制式的永磁电机转子结构。转子铁心表面磁极由若干小磁块阵列构成,阵列中磁块的宽度、厚度及磁块之间的间隔符合一种调制关系,合理设置转子上磁极的结构和位置使产生的气隙磁场波形更加接近正弦波。通过电磁场有限元分析和样机实验检测电机气隙磁场波形,实验表明气隙磁场正弦性畸变率实际降低了23.51%,说明本文提出改善表面式永磁电机气隙磁场波形正弦化程度的极宽调制方法和结构具有正确性和有效性。可见,表面永磁体极宽调制也是一种改善表面式永磁电机气隙磁场波形正弦化程度的有效方法。

In order to improve the sinusoidal waveform of air-gap magnetic field in surface-mounted permanent magnet machine （SMPMM）, reduce harmonic component and increase power index, this paper proposed a novel permanent magnet machine which its rotor is sinusoidal magnetic pole modulated structure. Rotor iron core surface was composed of a number of small arrayal magnetic blocks that its width, thickness and interval between arrayed magnets meet a modulation relationship. Setting the structure and location of these magnetic blocks reasonably on rotor and would made poles generated air-gap magnetic field more closely to sinusoidal waveform. At the same time, the magnetic field analysis is carried out by finite element method firstly and then designed a prototype to verify the results. According to experiments, the sinusoidal distortion rate of air gap magnetic field has dropped by 23.51%. It is show that the magnetic pole modulation method and arrayal magnetic blocks structure is effective and correctly to improve SMPMM magnetic field waveform sinusoidal. So, using sinusoidal magnetic pole modulation is also an effective way to improve air gap magnetic field in SMPMM.