基于气隙磁密差信号峭度因子的永磁同步电机局部退磁故障诊断

Partial Demagnetization Fault Diagnosis of PMSM Based on the Kurtosis of Air-gap Flux Density Difference Signals

该文提出一种新型基于气隙磁密信号差峭度因子的永磁同步电机局部退磁故障诊断方法。首先,建立永磁同步电机等效磁路模型,根据简化模型分析局部退磁故障后各极主磁路下径向气隙磁密的变化规律。然后,将预存健康电机空载状态下气隙磁密信号与测量的在线状态下气隙磁密信号作差并计算其峭度值,作为故障特征值。取健康电机空载状态下气隙磁密信号与不同工况下气隙磁密信号差峭度值的最大值作为参考值,根据故障特征值与参考值的大小诊断出局部退磁。最后,仿真和实验结果均验证提出的局部退磁故障诊断方法的有效性。

A new partial demagnetization fault diagnosis method for permanent magnet synchronous machine(PMSM)is proposed based on the kurtosis of air-gap flux density difference signals.First,the equivalent magnetic circuit(EMC)model of PMSM is established.According to the simplified EMC model,the change of radial air-gap flux density under the main magnetic circuit of each pole after partial demagnetization fault is analyzed.Then,by differentiating the prestored air-gap flux density signals in the no-load state of the healthy motor with the measured air-gap flux density signals in the online state,and calculating its kurtosis,the fault characteristic value is calculated.The maximum of kurtosis value of the difference between the air-gap flux density signal in the no-load state and the air-gap flux density signals under different working conditions of the healthy motor is taken as the reference value.Partial demagnetization is diagnosed according to the fault characteristic value and the reference value.Finally,both the simulation and experimental results validate the effectiveness of the proposed partial demagnetization fault diagnosis method.