Effect of voltage unbalance and stator inter turn short circuit on the characteristics of an induction motor

This paper presents simulation results of the combined effect of voltage unbalance and stator inter turn fault on the various characteristics of a three phase induction motor. The voltage unbalance is simulated by decreasing the voltage of the phase in which inter turn fault has occurred. A comparison between these characteristics and the characteristics of an induction motor with only voltage unbalance is also presented. Voltage unbalance and inter turn fault produce negative sequence current in similar manner. Their combined effect on the negative sequence current is presented in this work. For this purpose, an induction motor model with unequal number of stator turns has been developed and is then modified to develop a second model which can incorporate stator inter-turn short circuits. Simulation results obtained are observed to be in good agreement with other studies.