Modeling and Diagnostic of Incipient Interturn Faults for a Three-Phase Permanent Magnet Synchronous Motor

This paper discusses incipient end-winding interturn faults in the stator winding of a permanent magnet synchronous motor caused by the mechanical vibrations of the concerned turns. With aging, the end-winding blocking system becomes weaker and turns insulation degrades until its breakdown. The fault is modeled by an intermittent interturn short circuit between the turns of the stator end winding. Intermittent fault occurrence disturbs the stator currents as well as the reference voltages leaving a specific fault signature. The detection method uses a pattern-adapted wavelet to detect fault occurrence. In this paper, it is applied to the quadrature reference voltage. Simulation and experimental results confirm the effectiveness of the proposed approach.