Research On Control Strategy Of Aerodynamic Load For Large Wind Turbine

Due to the abundance of fossil fuel,the global climate has been deteriorated to an urgent degree and it is imperative to upgrade our energy structure.The current environmental problems can also be alleviated effectively with the development of wind power,which is one type of the clean energy.With the strong support by a lot of countries in wind power research technology,the capacity of wind turbine has been developed from tens of KW in the foremost to several MW presently.And a great progress has been made in the offshore wind turbine.However,it appears some new technical challenge with the capacity expansion.The unbalanced aerodynamic load brought by wind shear increases sharply as the enlargement of wind rotor diameter.It may affect the safety operation of wind turbine.Therefore,it is imminent to find the settlement of this problem.The paper chooses a domestic wind turbine with capacity 1.5MW,aiming at its rated power operation state.Firstly,the model of wind turbine is designed at MATLAB/Simulink platform.Next,it is considered the purpose of this operation state to control the fluctuation of output power near the rated power of the wind turbine.The synchronous variable pitch strategy based on PID control,the synchronous variable pitch strategy based on discrete fuzzy control and the synchronous variable pitch strategy based on modified discrete fuzzy control are proposed.Then,it is chosen the synchronous variable pitch strategy based on modified discrete fuzzy control as the foundation of individual variable pitch control by the simulation comparison.Finally,the reference individual variable pitch control based on azimuth angle with weight number assignment is designed to suppress the rotor’s axial aerodynamic load.The simulation results show that it performs excellent the synchronous variable pitch based on modified discrete fuzzy control in power stability.The individual variable pitch control strategy helps stabilize the power output and suppress the axial aerodynamic load when the wind speed range between rated speed and cut out speed.It demonstrates the effectiveness of the control strategies referenced.