关键词: 感应电动机, 转子偏心, 故障特征, 定子电流频谱, 小波包分析, 径向电磁力, 振动信号

Abstract:

Three diagnostic methods of rotor eccentricity fault of induction motor were studied. In the stator current spectrum method, the shortcomings of applying conventional FFT and the advantage of the wavelet packet analysis were pointed out. The improved wavelet packet analysis combined with FFT signal analysis method was proposed, and MATLAB was used to process current signals for verification. In the unbalanced magnetic pull analysis method, the fault characteristics of the radial force wave order and the relevant frequency are established by theoretical deduction, and the radial electromagnetic force characteristics of the normal, static eccentricity and dynamic eccentricity states were simulated and analyzed in ANSYS with an induction motor as example, and Fourier decomposition of the spatial and temporal distribution was conducted to obtain the force wave order and frequency distribution. The abnormal vibration caused by the fault of the rotor eccentricity mainly depends on the radial electromagnetic force wave, the simulation results provide the theoretical basis for the characteristic frequency proposed in the vibration signal analysis method.

Key words: induction motor, rotor eccentricity, fault feature, stator current spectrum, wavelet packet analysis, radial electromagnetic forces, vibration signal