Vibration Analysis of DFIG Stator Winding Inter-turn Short Circuit Fault

In order to study the Doubly-Fed Induction Generator (DFIG) stator winding inter-turn short circuit fault, firstly, air-gap characteristic of magnetic field after short circuit of stator winding under inter-turn is analyzed. Secondly, the formula of the air-gap flux density, air-gap permeance, air-gap magnetic field energy and the pulsating electromagnetic force acting on the stator is obtained. Finally, the vibration characteristics of the generator stator is got. For getting the signal of stator vibration, we take stator winding inter-turn short circuit experiment by using the DFIG of dynamic emulation laboratory. By analyzing the stator vibration with Hilbert-Huang Transform (HHT) method and comparing the signal of the Hilbert spectrum, the frequency component amplitude variation with time is achieved. Comparing Marginal spectrum among different signals, the fault feature parameters of stator winding inter-turn short circuit are acquired. At last, the experimental results are in good agreement with the theoretical results.