Hydraulic Variable Pitch Control System For Large-scale Wind Turbine Based On Flutter Suppression

Wind turbine blades will flutter under the coupling of aerodynamic and elastic forces,which causes structural damage to the blades.So flutter suppression of the blades has become a research hotspot.The research found that the existing variable pitch control system mostly aims at obtaining higher wind energy utilization,but it ignores the protection of the blades and also increases the probability of failure of the wind turbine.To solve the above problems,this paper proposes a brand-new hydrau-lic pitch system control scheme,which can adjust blade pitch angle in real time as wind speed changes,so as to restrain the flutter of the blade and protect the blade.The main contents are:Aeroelastic stability analysis for wind turbine blades.Firstly,establish the non-linear aeroelastic equation of the blade based on the ONERA model.Secondly,time-domain response method is used to to analyze the influence of changes in wind speed and pitch angle on the stability of blade aeroelastic models.Finally,using MATLAB software simulates the system to determine the variation of blade stability and flutter boundary conditions.The simulation results show that changing the ve-locities and adjusting the pitch angle will vary the vibration form and vibration dis-placement of the blade.Design blade hydraulic pitch system and research on control strategy.Firstly,design the hydraulic pitch system and detail explanation of the hydraulic circuit's oil circulation route under various working conditions.Secondly,select the main com-ponents of the hydraulic system after calculating the load force and flow.Then,de-velop mathematical models of hydraulic pitch systems and other components of wind turbines,and build simulation modules in Simulink software.Finally,optimize the model with optimal PID controller,fuzzy controller and fuzzy PID controller.The simulation results show that fuzzy PID controller has optimal control.Design PLC-based hydraulic pitch control system.Fristly,analyze the overall scheme of the control system,then discuss key technical issues and design the hard-ware and software components of the control system.Hardware architecture includes hardware structure planning,component selection,I/O ports distribution and hard-ware wiring.Software development focuses on the implementation of fuzzy PID al-gorithms in PLC,including the design of control processes,the preparation of control programs,and the establishment of human-machine interfaces.Build a semi-physical simulation experimental platform for wind turbine control system based on OPC communication technology.Firstly,based on previous work,determine the overall experimental plan.Secondly,implement OPC communication between PLC,MATLAB and Kingview and comlete the design of the loop simula-tion experiment platform.Finally,test the operating status of wind turbine pitch sys-tem.The experimental results verify the accuracy of the simulation results and the feasibility of the control method.