TURN FAULT DETECTION

A method for detecting turn faults in an induction motor comprises measuring at least two motor phase currents, at least two motor phase voltages, and the negative sequence impedance. Motor torque is estimated by employing the at least two motor phase currents and the at least two motor phase voltages. Motor pu slip is estimated by employing the motor torque. The motor pu slip is used to estimate the load variation effect on the negative sequence impedance. The negative sequence impedance is adjusted in accordance with the load variation effect, and it is determined whether the adjusted negative sequence impedance value indicates the presence of a turn fault.