Study On Load Reduction Of Floating Wind Turbine Based On DAC State Feedback Control And Monitoring

With the increasing pressure on decarburization requirements and diversification of energy investment portfolios,wind power development resources in land and shallow sea areas are more restricted in many markets,more and more countries are turning their attention to wind power resources in the deep sea.The floating foundation provides a viable solution for wind farms entering the deep sea area.The main challenge in deploying wind turbines is how to extract as much quality power as possible from wind energy while keeping the turbines running smoothly.However,the use of a floating platform introduces additional motions of six degrees of freedom.If we not actively or passively consider these motions,they will have a negative impact on power generation and wind turbine load.In addition,since the floating wind turbine has a complicated mechanical structure and the long-term operation in the high wind speed and high wave environment,the coupling problem between the floating wind turbine structure and the external disturbance will also strongly affect the normal operation of the floating fan.Therefore,it is urgent for us to study advanced control systems to minimize floating wind turbine load,suppress floating foundation motion and improve the power generation quality.We propose individual blade pitch control method based on state feedback to reduce the floating wind turbine load and suppress the floating foundation motion and tower vibration.And the disturbance accommodating control technique is introduced to control the disturbance of the varying wind speed for the stable operation of the floating wind turbine.In this paper,the spar-type wind turbine is taken as the research object,and the reduction of the wind turbine load is taken as the research purpose.The control problem of the floating wind turbine is discussed in detail and studied in depth.The specific work contents are as follows:(1)We studied the characteristics and operating principles of floating foundations,mooring systems and anchoring systems.Further understanding of the floating wind turbine operation process by analyzing the hydrodynamics and aerodynamics of the floating wind turbine.The operating principle of the important structure of the floating wind turbine is fully understood by analyzing the dynamic equations of the floating wind turbine.(2)Aiming at the load reduction problem of spar type wind turbine,the unbalanced aerodynamic loads of blades,front and rear vibration of tower and the motion of floating foundation are controlled.With individual blade pitch control,the blade pitch angle is changed to reduce blade load and tower vibration.In the linearization modeling process of the floating wind turbine,several degrees of freedom,such as the pitch and the first order motion mode of the tower,are considered to approximate the real floating wind generator system motion state as much as possible,so as to realize the highfidelity modeling of the system.(3)The state feedback control method is proposed to realize the design of the individual blade pitch controller to reduce the load and stabilize the output power as much as possible.Disturbance accommodating control technology is used to suppress the negative impact of wind speed changes on the stable operation of the unit.The FAST-MATLAB joint simulation platform is used to simulate the spar wind turbine model under different load conditions,and the effectiveness of the control method and the controller are verified.(4)The floating wind turbine monitoring system was developed through WinCC technology to monitor the important parameter information and load conditions of the unit.