Modeling and diagnostic of incipient inter-turn faults for a three phase permanent magnet synchronous motor

Insulation aging remains the leading cause of inter-turn fault in the stator winding of a PMSM. This aging weakens the insulation until its total deterioration. Types of the resulting faults differ according to the location of the weaknesses in the winding. During the last century, many fault diagnostic methods were developed. All these methods concern an existing permanent fault but not an intermittent one. The combination of end windings aging with electromagnetic efforts gives rise to intermittent inter-turns short circuit at the end windings. This paper contains a model of the intermittent short circuit and suggests an adapted online detection method based on the simulation and experimental results.