Research On Individual Pitch Control Strategy Of Wind Turbines Based On Active Disturbance Rejection Control

Wind energy has become the fastest growing new energy source with its advantages of renewable,non-polluting,high reliability,and low cost,and wind turbines have been constantly developing to large-scale and intelligent ones.Variable pitch wind turbine has become the mainstream wind turbine development models duo to blade pitch angle can be adjusted according to the characteristics of the need to capture a large wind energy.The individual pitch control wind turbine is showing great advantages based on the load-down control.However,due to the complex,nonlinear,and coupled nature of the individual variable pitch wind turbine,individual pitch control applications are limited.Therefore,in this paper,a large-scale individual variable pitch wind turbine model is established and an individual pitch controller is designed and simulated,which provide a theoretical basis for the application of individual variable pitch wind turbine.Firstly,the wind speed model with wind shear and tower shadow is established based on the wind turbine dynamics model and the influencing factors.Considering the uncertainties of wind turbine and unknowable external disturbances,a control model of wind turbine independent pitch control is established by selecting the rotation speed of each blade of wind turbine and wind turbine rotor.Secondly,aiming at the problem that wind turbine output power is not stable and the blade vibration is obvious,taking into account the nonlinearity and strong coupling of wind turbines and the influence of different wind speeds on the blades,an individual variable pitch is designed based on linear active disturbance rejection control and disturbance accommodating control.The controller uses the active disturbance rejection control theory to estimate the nonlinearity,coupling term and other unknown disturbances.The non-uniform wind speed is treated by the disturbance accommodating control.The effectiveness of the controller is verified by simulation using MATLAB.Finally,in order to design the controller easily and improve the control performance of the system,a fuzzy logic control-nonlinear active disturbance rejection individual pitch controller is proposed.Here,wind speed and wind turbine coupling and other unknown disturbances acting on each blade are treated as total disturbances.At the same time,the parameters of the nonlinear active disturbance rejection controller will be adjusted according to the fuzzy logic theory in real time.MATLAB simulation platform verify the superiority of the controller.