Stator winding inter-turn fault detection using control voltages demodulation

In this paper, a new technique for stator winding inter-turn fault detection in current controlled Permanent Magnet Synchronous Machines is proposed. The method is based on the online extraction of the second harmonic component of the voltage reference vector in the d-q frame. It will be shown that the amplitude of this harmonic depends on the inter-turn fault severity and the fault detection is realized by comparing the amplitude of the second harmonic to a threshold. This is a low cost method in CPU time. The experimental results show the validity of the proposed method.