钕铁硼永磁电机永磁体涡流发热退磁研究

Research on demagnetization of NdFeB permanent magnet caused by eddy current heat in permanent magnet motor

为了研究永磁体涡流损耗发热对永磁体磁性的影响,应用有限元分析软件对一台发生退磁的500 kW永磁同步电动机的永磁体进行涡流损耗分析.在600 kW永磁同步电机的研制过程中,采取了一些结构改进措施,并对样机永磁体进行了涡流损耗分析和稳态温度场计算.仿真结果表明,涡流损耗发热会导致永磁体退磁,而采取的结构改进措施能够有效减小涡流损耗.样机实验结果表明,新结构永磁同步电动机运行可靠,可为相关电机的设计提供经验.

In order to study the influence of eddy current loss heat on the magnet performances of permanent magnet, the analysis on eddy current loss for the permanent magnet of a demagnetized 500 kW permanent magnet synchronous motor （PMSM） was conducted with the finite element analysis software. In the development process of 600 kW PMSM, some measures for structural improvement were adopted. In addition, the analysis on eddy current loss and the calculation of steady-state temperature field for prototype permanent magnet were performed. The simulation results show that the heat generated from eddy current loss will cause the demagnetization of permanent magnet, and the adopted measures for structural improvement can effectively reduce the eddy current loss. The PMSM with new structure can operatereliably. And the present research can provide some reference for the design of relevant PMSM.