Analysis of inter-turn fault symptoms for the converter-fed induction motor based on the phase-shift calculation

In this paper a stator fault detection method based on monitoring of the phase shift between the line currents and phase voltages of the converter-fed induction motor is presented. The phase shift analysis is used as an indicator of the stator-fault-progression level. The mathematical model of induction motor, which includes the stator-winding fault is presented. The fault level is modeled by change of a number of shorted stator-winding turns. Next the new fault indicator is introduced. Comparison of simulation and experimental results of the converter-fed induction motor for different number of shorted turns and different load torque conditions is shown. Proper fault severity is obtained with the proposed fault indicator.