Detection and Discrimination Between Stator Winding Fault and Unbalanced Supply Voltage by Monitoring Rotor Bar Voltage

In the literature, the detection of different faults in induction motors using current, voltage, shaft induced emf, power, partial discharge, surges, magnetic flux, electromechanical torque, angular frequency component, temperature, vibration, noise, different gasses are reported. In this paper, the rotor bar voltage is used to detect of stator winding inter-turn faults and unbalanced in supply voltage. It is very difficult to discriminate between stator winding fault and unbalanced supply voltage. In the proposed technique, the rotor bar voltage is able to discriminate between stator winding inter-turn fault and unbalanced in supply voltage. The proposed abnormalities lead to variation in rotating magnetic field and thereby, rotor induced emf. Therefore, the rotor bar voltage is changes with respective stator winding inter-turn fault severity and unbalanced in supply voltage. By analyzing frequencies components induced in rotor bar voltage, the type of abnormality and their level of fault is identified. Online detection of the fault is possible for the given technique. The proposed technique is the novel technique which is, not yet reported for the detection of any kind of faults in any motors.