Research On State Observation And Control Method Of Wind Turbine System Based On T-S Fuzzy Model

Offshore wind power has become an important development direction of wind power generation,with broad development prospects,but it is also affected by bad weather and changeable marine environment,facing many challenges.The high latitude sea area may be frozen in winter,and ice load on the sea surface will affect the vibration and aerodynamics of the tower.The resulting ice accident will threaten the safety and life of the wind turbine,and bring a test to the pitch control of the wind turbine.In addition,the complex environment and variable operating conditions make the pitch actuator prone to pump wear,hydraulic leakage and other failures,leading to serious economic losses,and even endangering personnel safety.Therefore,considering the influence of sea ice disturbance,studying the wind turbine’s pitch control and condition monitoring under the combined wind and ice disturbance is conducive to improving the ability of offshore wind turbines to resist the ice load in cold waters,and improving the safety and life of the wind turbines.The research on the fault reconstruction and fault-tolerant control method under the fault condition of the actuator can significantly reduce the downtime of the wind turbine and reduce the maintenance cost,which is of great significance to improve the reliability of the wind turbine system.In this paper,pitch control and condition monitoring of offshore stationary wind turbine under combined wind and ice disturbance as well as fault reconstruction and fault-tolerant control of wind turbine under actuator fault condition are studied.The work mainly includes the following contents:(1)The mechanism model of each part of the wind turbine and sea ice load model are established.The linear processing of the model is carried out by using Taylor formula,and the state space model of single wind speed point of the wind turbine is obtained.The T-S fuzzy method is used to combine the single wind speed point model.Finally,a T-S fuzzy model of wind turbine which takes wind and ice disturbance into account and can cover a wide range of wind speed regions is obtained combined with the dynamic parameters introduced by FAST.(2)In view of the disturbance of the wind and the sea ice,the controller and observer are designed and the stability criterion is obtained combining with the state feedback control.T-S fuzzy control and methods of H∞ theory on the basis of the fuzzy model in order to ensure the safety and stability.The designed method has good steady-state accuracy and anti-interference ability.The example simulation is carried out under different combination of wind and ice conditions.The control effect of the designed controller is compared with that of PI controller in FAST software and the superiority of the designed controller and the effectiveness of the observer are proved.(3)In view of the actuator fault condition,the T-S fuzzy H∞ proportional integral fault/state observer is designed based on the T-S fuzzy model in this paper.Integration is introduced into the observer to improve the steady-state tracking accuracy and the disturbance inhibition ability.The stability of the augmented system is analyzed and the gain is solved.A fault tolerant controller is designed based on fault reconstruction.Finally,different fault conditions are simulated and analyzed.The simulation results show that the fault quantity of the actuator reconstructed by the fault observer can effectively track the actual fault value,and the designed fault-tolerant control method has good control effect.