On Variable Pitch Active Disturbance Rejection Control For Doubly-fed Wind Power Generation System

Wind energy is a kind of non-polluting,renewable and large reserves' green energy.With the global population growth and rapid economic development,increas:ingly energy demand and the worse environment that prompts countries to pay more and more attention to wind energy development.However,the energy density of wind energy is low,and strong intermittency and volatility,which brings great difficulties to the stable operation control of wind power generation system.When the wind speed is above the rated value,it is necessary to regulate the variable pitch control to ensure the wind turbine output power at the rated value.This paper designs a controller based on the linear active disturbance rejection method for the variable pitch of the doubly-fed wind power generation system.In view of the time delay,the variable pitch control method is adopted to design the controller.On the basis of the theoretical algorithm design,we can simulate and prove the active disturbance rejection method for the variable pitch control on the E-Wind Turbine simulation platform.The main contents of this paper are as follows:Firstly,this paper introduces the background and significance of wind power generation.The control mode and principle of wind turbine are summarized,and the control method and research status of wind power generation are analyzed in detail.Secondly,in order to solve the problem of variable pitch control in the doubly-fed wind power generation system,a linear active disturbance rejection control algorithm is used to design the controller.The simulation results are compared with the conventional PID control algorithm.The results show that the designed the linear active disturbance rejection controller has a short convergence time and when the system is disturbed,it can return to steady state quickly.Thirdly,considering the practical problems of the actuator with time delay in the variable pitch control of the doubly-fed wind power generation system,this chapter designs the linear active disturbance rejection controller based on the order increasing method and the improved linear expansive observer to improve the active disturbance rejection controller.The simulation results are compared with the conventional Smith predictor.The results show that the improved linear active disturbance rejection controller has a short convergence time,little fluctuation when disturbed,the system can quickly return to the steady state and can compensate for the Smith predictor of overly demanding model parameters.Then,linear active disturbance rejection control algorithm was designed to use on the E-Wind Turbine experimental platform of wind power generation simulation system by SCL.After compiling,a function block of active disturbance rejection control algorithm is generated to verify the effectiveness of the designed controller.Finally,the main work of this paper is summarized,and the future research direction is also discussed.