The detection of interturn short circuits in the stator windings of operating motors

The detection of shorted turns in a stator winding is possible in a variety of ways. The analysis of the motor current to perform this function is particularly attractive however, since current sensors are usually installed together with the motor for control and protection purposes. A winding function based method for modelling polyphase cage induction motors with this type of asymmetry is developed, and it is shown that the stator winding itself can be used as a sensor for detection of this type of fault. An experimental setup comprising a 3 kW delta connected motor loaded by a generator was used to validate this approach. The experimental results obtained clearly validated the theory.