Diagnosis technique for stator winding inter-turn fault in BLDC motor using detection coil

Brushless direct-current (BLDC) motors are widely used in industrial applications. These motors should be considered for high stability and reliability under faults which can seriously threaten safe operation. Among these fault types, a stator winding inter-turn fault (ITF) is one of the most common faults that occur in BLDC motors. Moreover, the propagation of the fault could quickly lead to shutdown of the motor within a few seconds. In order to prevent the problem, we proposed a diagnosis technique of ITF using variations of back electromotive force generated in detection coils in BLDC motors. The technique can relatively achieve more rapid response and lower cost than previous detection techniques, because the proposed technique does not require spectral analysis and complicated computation. The detection technique is verified by simulation and experiment under dynamic fault.