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标题:复合转子异步起动永磁同步电动机起动过程中永磁体退磁的研究 |
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作者:陈洪萍,王秀和 |
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2017年第1期 访问次数:291次 |
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摘要:复合转子异步起动永磁同步电动机是一种新型的永磁同步电机,它利用实心转子的涡流和铜导条实现自起动能力。为研究其起动过程中永磁体的退磁情况,建立了计及涡流、饱和等因素的有限元模型,分析该种电机起动过程中电机结构参数、起动条件对永磁体最小工作点及平均工作点的影响,并对起动过程中的永磁体退磁规律进行分析。研究发现永磁体的最小工作点与合成磁动势位置有关,当永磁体磁场与定转子合成磁场的夹角为110°、240°左右时,永磁体局部退磁风险大;最大去磁工作点出现在低转速,而不像普通异步起动永磁同步电动机那样出现在接近同步速。合成磁动势直轴分量能够反映永磁体去磁磁场的强弱,负载越重,永磁体的最大去磁平均工作点越低,对应的转速越接近同步速,出现最严重去磁的概率越大。 关键词:复合转子异步起动永磁同步电动机;起动过程;有限元法;退磁;最小工作点;平均工作点;合成磁动势 Abstract: Linestart permanent magnet synchronous motor with composite rotor is a new type of permanent magnet synchronous motor, which uses eddy currents induced in solid rotor and copper bars to achieve selfstarting capability. To research the demagnetization of permanent magnets during starting process, the finite element models considering saturation, eddy currents and other factors were established. Effect of structure parameters and starting conditions of the motor for the minmum operating point and the average operating point of the permanent magnets was analyzed. The rules of the permanent magnetsdemagnetization in the process of starting were also analyzed. The study found that the operating point of the permanent magnet is related to the synthetic magnetomotive force position. When the angle between the magnetic field of the permanent magnets and the magnetic field synthesized by stator and rotor is about 110°or 240°, part of the permanent magnets faces great risk of demagnetization; The largest demagnetization point of the permanent magnets occurs at low speed, rather than ordinary linestart permanent magnet synchronous motor that appears in the near synchronous speed. Synthetic directaxis of magnetomotive force is able to reflect the strength of the permanent magnetdemagnetization field. The load is heavier, the largest average demagnetization point is lower, which corresponding speed is closer to synchronous speed, and the probability of most severe demagnetization is greater. Key words: linestart permanent magnet synchronous motor with composite rotor;starting process;finite element method;demagnetization;minmum operating point;average operating point;synthetic magnetomotive force
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