A fault monitoring method for wind power generation system based on sliding mode observer

摘要

In this paper,a rotor current fault monitoring method is proposed based onaslid-ing mode observer. Firstly, the state-space model of the Double-Fed Induction Generator(DFIG) is constructed by vector transformation. Meanwhile, the stator voltage orientationvector control method is applied to decouple a stator and rotor currents, so as to obtainthe correlation between the stator and rotor current. Furthermore, the mathematical modelof stator voltage orientation is obtained. Then a state sliding mode observer (SMO) isestablished for the output current of the rotor of the DFIG. The stability and reachabilityof the system in a limited time is proved. Finally, the system state is determined by theresiduals of the measured and estimated rotor currents. The simulation results show thatthe method proposed in this paper can effectively monitor the status: a normal state, voltagedrop faults, short-circuit faults between windings, and rotor current sensor faults whichhave the advantages of fast response, high stability.