Fault Tolerant Control Of Wind Energy Conversion System Based On Generalized Sliding Mode Observer

Wind energy is one of the most promising renewable energy sources.Compared with traditional power generation,the advantages of wind power technology are becoming more and more obvious,which attracts widespread attention.However,the wind energy conversion system(WECS)is a complex coupling that is exposed to harsh environment for a long time,and frequent faults cause serious economic losses.Therefore,researching advanced fault diagnosis and fault-tolerant control technology has important theoretical research value and engineering application value for reducing the fault rate of the WECS and ensuring the reliable operation of the system.Based on the research of fault diagnosis technology and fault tolerant control strategy of the WECS,the subsystem models of wind turbine,transmission system and doubly-fed induction motor is introduced,and the state equation of the WECS is established in this paper.Based on the generalized sliding mode observer(GSMO)theory,the following research work was carried out:For solving the sensor fault problem of the WECS with measurement disturbance,the GSMO is designed to overcome the uncertainty of the WECS and the estimation of the state and sensor fault are realized.Sensor faults and measurement disturbances are reconstructed based on state estimation information.The sliding mode fault-tolerant control ensures the stability of the fault system and the maximum wind energy capture is achieved.Considering the actuator fault in the WECS,the splitting method is used to split the nonlinear part of the WECS into a constant matrix and an uncertainty matrix,and the state of the system is augmented.The actuator fault is augmented as a part of the system state,and the GSMO is constructed.The equivalent output control method is used to realize the fault reconstruction of the actuator,and the active fault-tolerant controller is designed to ensure the stable operation of the WECS.For the coexistence of sensor fault and actuator fault in the WECS,based on the GSMO,a post filter is introduced to construct a new dimension-added system to convert the sensor fault into the actuator fault for diagnosis.The robust adaptive sliding mode observer is designed,and the optimal sliding mode strategy is given to ensure the stability of the system state estimation.The algorithm of sensor fault and actuator fault reconstruction is given by equivalent output control.The robust fault-tolerant controller is designed,which can perform fault-tolerant control well and capture the maximum wind energy when multiple faults occur.On the Simulink platform of Matlab,the fault reconstruction and fault-tolerant control strategies of the above three cases are simulated and analyzed.The simulation results show that when the WECS has above three kinds of faults,the proposed fault reconstruction and fault-tolerant control strategy can ensure the stable operation of the WECS.