Early detection technique for stator winding inter-turn fault in BLDC motor using input impedance

This paper proposes an early diagnosis technique for the inter-turn fault (ITF) in the stator winding in a brushless DC (BLDC) motor using the input impedance. We have analyzed the varying characteristics owing to the ITF through various experiments and simulation. As a result, we have presented a simple method for fault detection. This technique can be applied without requiring a fast Fourier transform (FFT) and the calculation of the negative-sequence impedance. The fault detection system works on the basis of the comparison of the measured impedance with the database impedance. The variations in the characteristics owing to the ITF as well as the proposed technique have been verified through the simulation and the experiment.