Rotor faults diagnosis for induction motors based on the DC-side current of DC-AC converts

Through the analysis of the DC-side current spectrum of DC-AC converters when the rotor faults occur in induction motors driven by the DC-AC inverter, this paper discovers that the rotor fault signature information is distributed in the multiple frequency bands of DC-side current spectrum. A fusion algorithm is proposed. First the algorithm converts the fault signature frequency components distributed in the high frequency band to the low frequency band by using the complex analytical signal modulus squared function, then makes fusion-correlation processing with the low frequency signal and the complex analytical signal modulus squared function in order to make the fault signature frequency components more prominent in the spectrum, thus improves the reliability of diagnosis. Experimental results show that the method is effective on the rotor faults diagnosis in induction motors.