Experimental Assessment of Winding Inter-turn Short-circuits in Six-Phase AC Permanent Magnet Synchronous Motors

Multiphase permanent magnet synchronous machines are receiving more and more interest in safety critical modern industry applications and in wind turbines, owing to their higher reliability, with respect to the classical three phase machines. In this context, diagnosing the stator windings status is necessary to guaranty the required high machine performance. In the present paper, the detection of stator inter-turn short-circuit, for six-phase AC permanent magnet machine, is investigated. The main contribution of the presented investigation is the assessment of stator inter-turn short-circuit detectability based on spectral analysis derived from the space vectors of the back-emfs accessible in the different α-β planes. The presented results are validated by means of two-dimensional finite element analysis, and then by experimental results, showing a very good agreement.