永磁同步电动机中永磁体的三维涡流分析

3-D analysis of eddy current losses in permanent PMSM magnets

有效准确地分析在正弦电压驱动下永磁同步电动机中永磁体的涡流损耗是研究实际电机发热及温升的关键。该文利用有限元方法,建立了场路紧密耦合的三维模型,对一台500 kW/60 H z内嵌式永磁同步电动机进行仿真研究,分析了在三相正弦电压源驱动下的气隙旋转磁场、转矩及考虑时间谐波作用下永磁体的涡流损耗,并阐明了电流的不同谐波分量对永磁体涡流损耗的影响。分析结果表明,轴向分割永磁块能将永磁体中涡流损耗降低至50%,并且减小齿槽谐波电流也能有效地降低永磁体中涡流损耗。

The eddy current losses in permanent magnets must be efficiently and accurately predicted to analyze the temperature increase in the permanent magnet synchronous motors （PMSM）. A tightly coupled field-circuit method was used to simulate the eddy currents in the magnets of a 3-D model of a 500 kW/60 Hz interior PMSM with a three-phase sinusoidal power supply. The input current, rotating magnetic field and output torque are calculated to investigate the eddy current losses in the magnets including the effect of time harmonics. Simulations show that segmentation of the magnets in the axial direction reduces the eddy current losses by more than 50% compared with results of a 2-D analysis that can not take the segmentation of the magnets into account. Reduction of the slot ripples also significantly reduces the eddy current losses in the magnets.