基于振动噪声信号的永磁电机故障诊断

Fault Diagnosis of Permanent Magnet Motors Based on Vibration and Noise Signals

为了提高电机的安全性和可靠性,对电机进行故障诊断非常重要。提出了一种计算与测试相结合的综合故障诊断方法。分析了永磁同步电动机噪声产生机理,利用解析法推导出径向电磁力、轴承故障、空气动力噪声特征频率表达式。对一台7.5 k W、1500 r/min异步起动永磁同步电动机进行测试,提取了电机正常运行、断电瞬间、拆除风扇前后各种情况时间和频域的波形。通过特征频率与频谱图中峰值频率的对比分析,判断出了电机振动噪声过大故障的位置和原因,并采取相应的措施成功进行了抑制,使噪声声压级由70.2d B(A)减小为62.3d B(A),证明了该方法应用于电机故障诊断的可行性。

It is very important to implement fault diagnosis for permanent magnet synchronous motor（PMSM）in order to improve its safety and reliability. A new method for fault diagnosis of calculation and test com-bined was proposed in this paper. The noise generation mechanism of PMSM was analyzed. The characteris-tic frequency analytical expressions of radial electromagnetic force, the bearing fault, the aerodynamic noisewere induced. A 5.5 kW, 1500 r/min line-started PMSM time and frequency domain was tested, includedthe normal operation, power-off moment, remove the fan before and after. By contrasted the characteristicfrequency and peak frequency values, the location and cause of the vibration and noise too large faults weredetermined, then the appropriate measures were took to carry on the active control, the sound pressure levelby 70.2 dB（A） was reduced to 62.3 dB（A）. The validity of the proposed method is confirmed in the faultdiagnosis.