Designing And Dynamic Property Analyzing Hydraulic Variable Pitch System Of Wind Turbine

Wind energy is a clean and sustainable energy and has become an important part of the strategy of sustainable development in many countries.Pitch control system as one of the most important technology in the large wind turbine has been extensively studied. this thesis applies theoretical analysis, simulation analysis and experimental validation to the study of the wind turbine hydraulic pitch control system.This paper first describes the structure and working principle of wind turbines, as well as introduce the development and research status of wind turbine research status, then explains the significance of research on the subject and put forward the main contents of this paper. Based on the aerodynamic analysis of wind turbine,the variable-pitch control strategy of the wind-turbine was derived. The thesis figures out the needed thrust pitch of the wind turbine under extreme operational conditions through the theoretical analysis. The mathematical model of Variable pitch wind turbine was built and simulated. Simulation result is given to verify the reliabilities of theoretical analysis.In the traditional hydraulic driving pitch system of wind turbine, the Variable pitch mechanism works with a piece of crank link connected mechanism through which the three blades are driven synchronously.This paper calculate pitch driving force, force and load flow of blade and designe a hydraulic pitch control system on this basis, and describe the working principle and a variety of conditions, including off paddle, paddle open and emergency feathering of the hydraulic control system conduct in detail. Then calculating and selecting the main hydraulic components.The mathematical model of Hydraulic Variable Pitch Control System of Wind Turbine has been built, conducted the simulation analysis of i and verified its stability. Its conclusion illustrate this hydraulic variable pitch control system model is feasible and its parameters are right. After adding PID correction link, it tunes the coefficients of PID controller based on Ziegler-Nichols method and then improve the dynamic property of the control system.