Back-EMF Based Detection of Stator Winding Inter-turn Fault for PM Synchronous Motor Drives

In this paper, a new technique for stator winding inter-turn fault detection in Permanent Magnet Synchronous Machines is proposed. It consists of extracting the mechanical power second harmonic component which appears when the machine is faulty. This harmonic is processed in order to obtain a fault indicator. It will be shown that the amplitude of this indicator depends on the inter-turn fault severity. The proposed technique allows detecting the fault in real time and its implementation is easy. The experimental results show the validity of the proposed method.