电动汽车用ISG永磁电机在弱磁条件下的永磁体涡流损耗分析

Analysis of the Eddy Current Losses of Permanent Magnets in Permanent Magnet Synchronous Motors for Electric Vehicles Under Weak Magnetic Conditions

针对内转子内置式永磁同步电机在高速运行时转子永磁体所产生温升严重的问题,以"一"型和"V"型两种不同磁极结构的35kW永磁同步电机为研究对象,在永磁体总量和磁极分块相同的情况下,利用有限元法与解析法,分析了两种磁极结构在弱磁条件下永磁体表面的磁通及其变化情况,探究了两种磁极结构的电机在相同的弱磁条件下不同转速、不同弱磁角和不同去磁电流时的转子永磁体涡流损耗大小和特点,得到在相同弱磁条件下"V"型磁极结构的永磁体涡流损耗大于"一"型磁极结构的结论。最后制造样机并进行试验,验证了有限元模型的有效性,为永磁同步电机在弱磁条件下的永磁体涡流损耗情况提供参考。

In view of the serious temperature rise caused by the internal rotor permanent magnet synchronous motor(PMSM)with interior permanent magnet at high speed,the 35 kW PMSM with the"one"type and"V"type magnetic pole structures are introduced.Based on the same mass and blocks of permanent magnets,the magnetic flux on the surface of the permanent magnet and its change under the weak magnetic condition are analyzed by the finite element method and analytical method.The eddy current losses and characteristics in the motors with two magnetic pole structures are explored at different speeds,weak magnetic angles and demagnetization currents under the same weakening field condition.The eddy current losses of the motor with"V"type magnetic pole structure is larger than that of the motor with"one"type magnetic pole structure under the same weakening field condition.Finally,the prototype is fabricated and tested to verify the effectiveness of the finite element model,which provides a reference for the eddy current losses of permanent magnet synchronous motor under weakening field conditions.