矢量控制下永磁同步电机的损耗分析

Loss Analysis for Permanent Magnet Synchronous Motor under Vector Control

为了精确计算电机损耗,以一台永磁电机为例,采用矢量控制原理及有限元分析方法,建立了永磁电机二维模型。对该电机模型定子侧进行区域划分,并对不同工况进行有限元仿真计算,详细分析电机在不同工况下的各区域损耗,对损耗曲线产生波动的原因进行深入分析,并选取A相电流进行了仿真计算与实验结果的对比验证。结果表明:电机铁耗主要分布在定子侧,满载时定子铁耗占总铁耗的98.3%,半载时占总铁耗的98.5%;转子铁耗主要为涡流损耗,满载时转子上的涡流损耗占转子总铁耗的97.5%,半载时占转子总铁耗的97.6%;涡流损耗主要分布在永磁体上和转子上,其中永磁体上的涡流损耗大于转子上的涡流损耗,满载时永磁体上的涡流损耗占总涡流损耗的89.3%,半载时占总涡流损耗的89.4%;随着负载的降低,定子铁耗占总损耗的比例逐渐增加。计算结果与实测值相吻合,误差满足工程实际要求,验证了该研究方法及结果的正确性。

To accurately evaluate motor losses, a 2D model of permanent magnet motor is established with finite element method following vector control principle. The stator of the motor model is divided along radial and simulated under different loads. The losses in different domains and the wave of loss curves are discussed in detail. Then a simulated phase current is compared with the measured phase current. The results show that motor iron loss appears mainly in the stator, the stator iron loss gets to 98.3% of total iron losses under full load, and 98.5~/6o of total iron losses under half load. Eddy current loss appears mainly in the permanent magnet and rotor, rotor eddy current loss gets to 97.5% of total rotor iron losses under full load, and 97.6% of total rotor iron losses under half load~ permanent magnet eddy current loss is greater than rotor eddy current loss, permanent magnet eddy current loss gets to 89.3% of total eddy current losses under full load, and 89.4~ of total eddy current losses under half load. The proportion of stator iron loss in total motor losses gradually increases with the reduced load. The simulation results agree with the measured ones, and the error falls bellow the engineering requirement.