The Wind Turbine Controller Design And Analysis Of Stability Region

Excessive use of conventional energy sources,making the problem even more serious environmental pollution,in order to solve environmental problems,people have paid more and more attention on wind power.Large wind turbines are complex multi-variable nonlinear dynamical system with uncertainties and multiple interference,making it difficult to obtain wind turbines precise mathematical model,so that the wind turbine controller is difficulty to design;Some fault may occur when the turbine is running,making the wind turbine system deviate from the stable point,and this may destroy the turbine,so the stability region is important to guide the wind turbine operation.In this thesis,variable speed pitch wind turbines are used for the study.First,the dynamic characteristics of wind turbines are analyzed and wind energy utilization coefficient is obtained.Then the basic control strategies are described.The wind speed model,wind turbine model,transmission model,generator model and pitch actuators model are established.Based on these models,the wind turbine control system simulation platform is built.In this thesis,the original control problems for are transferred into stability issues,and a torque controller and a pitch controller are designed.When the wind speed is less than the rated speed,the torque adjusts the torque controller to achieve maximum power output;when wind speed is higher than the rated wind speed,the pitch angle is adjusted to limit wind capture and achieve the output power stability.The stability region is estimated by Lyapunov method.To verify the stability region is active in other controllers,the controllers are designed by the additive decomposition method and the relationship of the status and stability region are analyzed.Finally,the numerical simulation is accomplished.The results show that the controller has achieved good control effect,and the turbine runs stably in the stable region.The method has certain practical possibility,and the stability region provides a basis for the maintenance of the wind turbine.