Fault Detection Of Induction Motor Based On Wavelet Analysis

With the development of science and technology and the progress of modern technology, in the field of automation of the production process can be seen everywhere in the form of asynchronous motor, ensure safe and reliable operation of motor, reduce economic consumption, prevent staff injury by accident, the system is in a safe operating state in a timely manner to prevent further expansion of the fault becomes particularly important.The original signal is the normal operation of the motor in steady state, when the fault occurs will break the steady state, the fault signal will appear sudden many instantaneous signal components. Although the previous Fourier method can realize the analysis and processing of signal, but cannot analyze and deal with the instantaneous burst signal, so fault diagnosis cannot be well applied to the motor.Wavelet transform of signal local analysis ability and multi-resolution feature that makes it can proceed from the overall signal can also signal a local for proceed, to realize the signal analysis and processing, so the application of wavelet transform in fault diagnosis of motor is very extensive. Firstly, Fourier and wavelet transform are compared, wavelet transform can make the diagnosis more accurate results are obtained in the fault diagnosis of motor, secondly, the wavelet packet transform can prevent the noise and the signal can be transmitted, can be compared to the Bandpass filter, So to be able to signal de-noising processing, in this paper, through concrete examples show that the wavelet packet de-noising in signal more obvious effect, at last, this paper introduces the working principle of asynchronous motor, and the fault reason and condition, frequency characteristics of different fault conditions.When the motor fault occurs, the vibration signal will be different degrees of changes,including amplitude, vibration mode and vibration signal frequency and the vibration of each fault corresponding changes will be different, according to the relation of thecorresponding fault diagnosis as the basis, the vibration signal by wavelet packet decomposition and reconstruction method for further processing, can get the energy feature of each part of the band, according to the difference of energy characteristic to obtain the final results of fault diagnosis. Digital simulation analysis shows that wavelet transform in asynchronous motor fault diagnosis based on vibration signal and fault diagnosis based on the stator current signal is effective.