Research On Dynamic Load Control Strategy Of Large Scale Double Feed Wind Turbine

With the rapid development of wind energy technology and industry, the capacity size of wind turbine become more and more bigger, the rotor, drive train and tower become more and more flexible, which lead to the wind turbine dynamic load go into complexity and inclemency. The 3MW double feed wind turbine is taken as the research object in this thesis based on the project supported by National Key Technology Research and Development program. The goal of the research work is to reduce the dynamic load through special control strategy design, and the key is to solve the problem from the difficulty in building the rotor aero model and disturbance effect. Following is the main contents of this thesis:A kind of double loop control strategy is put forward based on analyses of wind turbine dynamic load and its influencing factor. In order to reduce the dynamic load on the premise of ensuring the output energy, the dynamic load active control loop is leaded into the power and speed controller, in which the pitch system and the inverter is taken as actor.The active control method of rotor unbalance aerodynamic load and tower top load is studied. Aimed at the complex noline coupling and the difficulty in building the mathematic aero model of rotor, a kind of rotor dynamic load active control strategy based on general model. It is a model free method. and it is good at handled the noline coupling of three pitch angle and rotor dynamic load and the sensor delay. The GH bladed simulation result shows that the dynamic load active control strategy based on general model can reduce the rotor unbalance load, restrain the coupling vibration between rotor and tower, and reduce the tower top load.The active control method of drive train rotation dynamic load is studied. Aimed at the parameter perturbation problem from the uncertainty factor, such as gear elastic deformation, gear engaging error, dynamic stiffness and damp of flexible coupling, the drive train dynamic model including uncertainty factor effect is built. An active disturbance rejection rotation dynamic load active control strategy is put forward. The strategy reduces the load through torque vibration surprising based on extended status observer and nonlinear state error feedback. The uncertainty factor effect and external disturbance are summarized as general disturbance. The general disturbance is estimated by extended status observer and compensated in nonlinear state error feedback. The GH bladed simulation result shows that the active disturbance rejection load active control strategy can surprises the drive train torque vibration and reduce the rotation dynamic load.The dynamic load active control strategy is verified through measurement on a wind turbine control system test bench. A 3MW wind turbine control system test bench is built. The strategy is tested through simulate the wind of classic wind farm. The test data shows that the new presented control strategy is feasible and effective.