基于实测定子电流的表贴式永磁同步电机转矩波动系数计算方法

Method to Calculate Torque Ripple Coefficient of Surface-mounted Permanent Magnet Synchronous Motor Based on Measured Stator Current

利用实测定子电流计算转矩波动系数有助于监测永磁同步电机在实际工况下的转矩波动程度以及根据其变化进行故障预测。针对采用d-q轴数学模型、矢量控制的表贴式永磁同步电机,考虑永磁同步电机定子电流基波、谐波与转子磁场基波、谐波的相互作用对转矩波动的影响,推导出转矩解析计算模型。实测定子电流以及转子磁场进行傅里叶分析,确定主要谐波阶次以及转矩波动的主要阶次。依据对实验实例的分析,提出了利用实测定子电流计算永磁同步电机转矩及其波动系数的方法。结果表明能够用于实时监测永磁同步电机在实际工况下输出转矩波动系数。

Using actual measured sub-currents to calculate the torque ripple coefficient is helpful to monitor the torque ripple degree of the permanent magnet synchronous motor under actual working conditions and predict faults based on its changes.For the surface-mounted permanent magnet synchronous motor adopting dq axis mathematical model and vector control,considering the influence of the fundamental wave and harmonics of the stator current of the permanent magnet synchronous motor and the fundamental wave and harmonics of the rotor magnetic field on the torque fluctuation,it is derived Torque analytical calculation model.Measure the sub-current and the rotor magnetic field for Fourier analysis to determine the main harmonic order and the main order of torque ripple.Based on the analysis of the experimental examples,a method for calculating the torque and ripple coefficient of the permanent magnet synchronous motor using the measured sub-current was proposed.The results show that it can be used to monitor the output torque fluctuation coefficient of permanent magnet synchronous motor under actual working conditions in real time.