Detection of Stator-Winding Turn-to-Turn Faults in Induction Motors,Based on Virtual Instrumentation

A virtual instrumentation system for stator turn-to-turn winding-fault detection is presented in this paper. The system can be adopted for industry and academy as a useful tool to prevent unexpected downtime or severe damage to induction motors. The high-frequency carrier-signal injection technique is used to obtain information on machine stator winding. Measurements of the resulting negative-sequence current are used to detect turn-to-turn faults. Since the stator windings are fixed in space, a turn-to-turn fault gives rise to a stationary saliency which appears as a DC component in the spectrum of the negative-sequence carrier-signal current. The proposed virtual instrument shows the relationship of the magnitude of the DC component to the grade of failure of the stator winding.