Stator fault detection of the PMSG under the sliding mode control in wind energy conversion system

This paper proposes a method for the diagnosis of stator inter-turn short circuit fault for Permanent Magnet Synchronous Generators (PMSG). This approach uses the parameter estimation of the per-phase stator resistance in closed loop control of variable speed of Wind Energy Conversion System (WECS). In the presence of an incipient short-circuit fault, the estimation of the stator resistance in the synchronous reference frame does not make it possible to give the exact information. To solve this problem, a novel fault diagnosis scheme is proposed to estimate the stator winding resistance in three-phase reference frame. The per-phase stator resistance of PMSG is estimated by the on-line MRAS algorithm. This diagnosis detects the fault severity in real time for each stator winding phase. The approach is implemented without the addition of any new devices; moreover, the estimated parameters will be used on the control performance improvement. The simulation results demonstrate that the proposed method can estimate the faulty phase.