Design And Experiment Study Of Electro-hydraulic Proportional Variable Pitch System For Wind Turbine

With the gradual increase of energy demand and the serious environmental pollution in the world,human beings are in urgent need of a clean,pollution-free and renewable energy.Wind power industry has a rapid development in the last ten years,great efforts are made on wind power technology research in all countries year by year.The control strategy of wind turbine operation is a research hotspot.While,variable pitch control is the main power regulation method for wind energy collection and conversion currently,so hydraulic variable pitch system is designed and its experiment is analyzed in this paper.Firstly,the research status of wind power industry at home and abroad is briefly introduced.Based on the theory of the aerodynamics,the performance and force of fan blades are analyzed,and the theory of variable pitch constant power control is introduced.Then Workbench CFX is used to do the fluid-solid coupling analysis.Secondly,the electro-hydraulic proportional control technology is adopted to design the schematic diagram of the variable pitch hydraulic system.The system has the advantages of simple control principle,high positioning accuracy and strong anti-bearing capacity.Then the mathematical model of electro-hydraulic proportional variable pitch hydraulic system is established,and the corresponding PID control model is established,and the dynamic performance of the system has been analyzed.A fuzzy neural network controller based on power variation is designed for nonlinear and multivariable uncertainties of variable pitch control system.Compared with traditional PID controller,it can adapt to the characteristics of wind power system better,and has strong robustness and anti-interference ability.Finally,the hydraulic system simulation is carried out by AMESim.The variable pitch hydraulic system is a valve-controlled cylinder system essentially.In order to simplify the calculation,the AMESim is used to model the electro-hydraulic proportional directional valve,and the valve-controlled hydraulic circuit is modeled and simulated.According to the simulation results and the actual test results,Configuration parameters are corrected to achieve the best results.Then the experimental platform of electro-hydraulic proportional position servo system with valve-controlled cylinder has been built,finish doing static performance test of proportional directional valve and position controlling experiment study.Experiments show that this hydraulic system designed in this paper can meet the given working condition requirements.