电动车永磁同步电机转矩波动分析及测试

Analysis and test for torque ripple of permanent magnet synchronous motor for electric vehicle

研究了电动车传动系统谐振的特点,推导了电动车传动系统谐振方程,论证了永磁同步电机转矩波动引起整车低速抖动的机理。建立了气隙谐波磁场产生转矩波动的数学模型,揭示了永磁同步电机转矩波动的频率与幅值特性。根据电动汽车低速谐振特性与同步电机转矩波动幅频的对应特点,并且针对国内外少有文献对车用电机转矩波动测试方法进行分析的现状,搭建了转矩波动动态测试台架,通过试验验证了转矩波动频次分析的正确性,同时为了弥补波动动态测试会产生幅值及相位失真的不足,提出一种新型静态堵转测试方法,为电动汽车用永磁同步电机提供了准确的转矩波动测试评价手段。

The characteristic of powertrain torsional vibration was studied in an electric vehicle,the mathe-matical equation of powertrain torsional vibration was built, and the reason was that the electric vehicle powertrain resonates with motor＇ s torque ripple in low speed condition. Then, the model of torque ripple due to non-sinusoidal magnetic field distribution was built, and the orders and frequencies of torque rip-ple in PMSM （ permanent magnet synchronous motor） were analyzed. According to the relationship be-tween the torsional vibration in low-speed of the electric vehicle and the frequency of motor torque ripple, for the situation that there were few literatures on analyzing the torque ripple and test method of PMSM in electric vehicles, a dynamic torque ripple test bench was built. The correctness of the torque ripple fre-quency analysis is verified by testing. Meanwhile, in order to make up the amplitude and phase distortion caused by the dynamic test, a new locked-rotor static method for torque ripple test was proposed. It pro-vides an accurate means of testing and evaluation for the torque ripple of PMSM in electric vehicles.