Adaptive Filter with Multiple-Scale Decomposition Rotor Broken Bars in Induction Fault Diagnosis

There is a very small additional current component of frequency in the stator current signal when motor has broken rotor bars.So adaptive notch filter is applied to process the signals of the stator current in induction motors.The variable step size LMS algorithm and the multiple-scale wavelet transform are merged into the adaptive filtering system.A method is proposed, that is a LMS adaptive filtering algorithm with modified variable step size based on multiple-scale wavelet transform(MSWT-MVSS-LMS).It can eliminate interference from power frequency component to frequency component of broken rotor bar and achieve precise identification to frequency component of broken rotor bar from FFT.The result is a great help to extract the feature component of rotor fault and improve the sensitivity of fault diagnosis.The simulation show that the method is valid and effective.