分数槽集中绕组表贴式永磁同步电机转子损耗

针对损耗模型很难准确地计算转子损耗且三维有限元方法占用大量时间的问题,基于二维运动瞬态有限元法,研究了1台36槽42极单层分数槽集中绕组永磁同步电机在恒转矩区和弱磁区以最大转矩运行时的转子损耗,并且研究了高速工况下永磁体轴向分段数量、槽口宽度以及气隙厚度对永磁体损耗的影响。研究发现,在整个转速区间永磁体损耗占转子总损耗的90%以上；转速低于1 500 r/min时,转子铁心磁滞损耗高于涡流损耗,高于1 500 r/min时涡流损耗明显高于磁滞损耗。永磁体分段能明显降低永磁体涡流损耗;负载工况下改变槽口宽度,永磁体涡流损耗几乎没有变化；增大气隙厚度虽然能降低永磁体损耗,但是效果并不明显；同时,更改槽口和气隙厚度会使电感发生变化,并进而影响电机的运行性能。

Rotor Loss of Surface Permanent Magnet Synchronous Motor withFractionalSlot Concentrated Windings

Considering the difficulty to calculate rotor losses accurately by loss model and too much time by threedimensional finite element method, the rotor loss of a 36 slots 42 poles singlelayer surface permanent magnet synchronous motor with fractionalslot concentrated winding was calculated based on the twodimensional motion transient finite element method operating at maximum torque both in constant torque region and in fluxweakening region. Additionally, the effects of the number of axial segments, slot width and air gap thickness on the loss of permanent magnets at high speed were investigated. It was shown that the magnet loss accounted for more than 90% of the total rotor loss in the whole speed range, the hysteresis loss of the rotor core was higher than the eddy current loss when the speed was lower than 1 500 r/min, and the eddy current loss was obviously higher than the hysteresis loss when the speed was higher than 1 500 r/min. The eddy current loss of the magnet could be reduced obviously by segmenting the permanent magnet; changing slot width contributed nothing to magnet loss under load condition;increasing the air gap width had no obvious effect on reducing the loss of permanent magnet. Meanwhile, changing the slot width and the thickness of the air gap would change the inductance and affect the performance of the motor.