Online Turn Fault Detection of Interior Permanent-Magnet Machines Using the Pulsating-Type Voltage Injection

This paper proposes a stator winding fault detection for interior permanent-magnet (PM) machines based on the pulsating-type voltage injection. By superimposing a pulsating voltage on d-axis with respect to the rotor-referred synchronous frame, measurable winding fault reflected signals occur in the injection induced current ripples. Comparing to prior diagnostic techniques, the proposed injection method is immune to the rotor saliency because saliency reflected current harmonic is decoupled once the pulsating voltage is exactly injected on rotor d-axis. It results in the improved fault detection performance on interior PM (IPM) machines as well as other salient machines. An IPM machine with three sets of turn-to-turn short is built to verify the proposed fault detection method.