A low cost method for the diagnostic of asynchronous motors in case of rotor defects

The detection of rotor fault induction motor has been studied for some decades. But the main difficulty is to detect the characteristic frequency component specific to the defect. Many technics are devoted with the spectral analysis but the most commun problem is the spectral resolution in term of frequency. Classically, the motor has to operate under steady state and under nominal conditions. In order to get rid of these constraints, we proposed in this paper a practical approach for the detection of rotor fault in induction motor. This method is based both on the double analysis of the stator current and of the voltage induced in case of rotor defect. Both the current and voltage distortion show up significant information about the squirrel-cage quality. Several experimental results coming from tests are presented and highlight the effectiveness of this approach.