Active Disturbance Rejection Control For Wind Turbine Fatigue Load

Wind energy is a kind of clean,safe and sustainable renewable energy with great potential.To capture maximum wind energy,wind power technology has developed rapidly.However,with the large-scale grid-connection of wind turbines in recent years,the output power fluctuation of wind turbines increases frequently under the influence of uncertain wind energy and other factors,which leads to the increase of wind turbine fatigue load,reduces the operating life and economy of wind turbines,and brings great influence to the frequency regulation of power grid.In order to solve this problem,an active disturbance rejection control technology and its parameter setting method considering wind turbine fatigue load are proposed in this paper,and good results are obtained in the simulation.The main achievements of this paper are as follows:1)The operation structure and power generation principle of the doubly-fed induction generator(DFIG)are analyzed in detail.Accordiing to the knowledge of aerodynamics and mechanics,and the wind turbine model is built on Matlab/Simulink platform.The accuracy of the wind turbine model is verified by the dynamic characteristics analysis.2)The idea,principle,advantages and disadvantages of PID control and active disturbance rejection control are analyzed.The n order linear active disturbance rejection controller(LADRC)and extended state observer are analyzed.It also analyzes and compares the parameters setting methods of linear active disturbance rejection controller,which are widely used at present,bandwidth method and PI conversion method,and finds that the parameters still have some shortcomings after setting.3)The main factors affecting fatigue load of wind turbine shaft torque and tower bending moment are analyzed and the fitness function of optimization algorithm is established.By comparing the common intelligent optimization algorithms,it is found that the particle swarm optimization algorithm has better optimization effect on the wind turbine controller.The parameters that affect the particle swarm optimization algorithm are analyzed and selected,and the parameters of the active disturbance rejection controller are optimized under the given turbulent wind speed and the wind turbine operation is compared with the original PI controller,which verifies the feasibility of the parameter control optimization method proposed in this paper.4)Considering the influence of the change of wind turbine actuator on the fatigue load,a parameter optimization method was proposed to reduce the fatigue load of wind turbine by reducing the change rate of the actuator,and the influence of the parameter value in the fitness function on the final optimization effect was analyzed.The simulation and comparative analysis of the optimized LADRC and PI controller under different working conditions show that the fluctuation range of wind turbine pitch angle and rotor speed is significantly reduced,and the fluctuation of shaft torque and tower bending moment is reduced,which reduces the mechanical loss and increases the operating life of the wind turbine,which proves the effectiveness of the control optimization method proposed in this paper.