Detection of stator winding inter-turn short circuit fault in induction motors

Based on the multiloop model presented previously, the transient simulation of stator winding inter-turn short circuit fault (SWITSCF) in induction motors, as well as the relevant experiments, has been completed. By thoroughly analyzing the simulation results under a variety of conditions, this paper draws a conclusion that stator negative sequence apparent impedance is the most reliable fault feature with satisfactory sensitivity for the SWITSCF detection. Meanwhile, the experiment results clearly indicate that, for an actual motor operating on site, stator negative sequence apparent impedance is fluctuating with time to a certain extent, as would deteriorate the detection reliability/sensitivity. As a result, the low-pass-filtered stator negative sequence apparent impedance is chosen as the fault feature to reliably and sensitively detect SWITSCF in induction motors. The experiment results demonstrate that this technique is valid and effective for the SWITSCF detection.