Research On Vibration Control Of Floating Of Wind Turbine Structure Based On Tuned Mass Damper

With the increase of global energy consumption and the further exploitation of non-renewable energy,wind energy,as a renewable green energy,has attracted great attention.At present,the development of offshore wind energy in China is still in its infancy,and offshore wind turbine is a very complex system with high cost.The design and manufacture of offshore wind turbine are facing enormous challenges.Therefore,in order to ensure the safe and reliable operation of offshore wind turbines,the vibration control of offshore wind turbines is studied in this paper.The tuned mass damper(TMD)is proposed to suppress the vibration of floating wind turbines and reduce the load on the units.The main research contents include:1.The theory and method of offshore wind farm characteristics,aerodynamic load and wave load are studied.The aerodynamic load is calculated by blade element momentum theory,and the hydrodynamic load is calculated by the combination of Morrison equation and potential flow theory.2.The theory and method of wind field characteristics,aerodynamic load and wave load are studied.The aerodynamic load is calculated by blade element momentum theory,and the hydrodynamic load is calculated by the combination of Morrison equation and potential flow theory.3.Taking a 5 MW semi-submersible offshore wind turbine as an example,based on the simple coding genetic algorithm(SCGA),the natural frequency and damping ratio of the tuned mass damper(TMD)with stroke limitation and no stroke limitation are optimized.The influence of TMD on the displacement and load of the key position of the wind turbine was discussed.Under the five conditions,the wind turbine model is simulated.The simulation results show that effect of TMD with stroke limitation is worse than that with no stroke limitation.But considering the real size of the nacelle space,TMD stroke limitation still has certain reference significance,and the longitudinal vibration damping effect is better than that of lateral vibration reduction effect.4.Take 5MW semi-submersible offshore wind turbine as the research object.The wind turbine system is identificated according to the principle of system identification based on least square method,and the hybrid mass damper(HMD)control system is designed based on H? controller.At last,the wind turbine model is simulated under five conditions.The simulation results show that the HMD inhibitory effect to evaluation indexes is more obvious compared to the passive control.Meanwhile,the gain coefficient and the feedback coefficient on the controller robust stability,the control force,and the inhibitory effect to evaluation indexes will have an impact.Therefore,in order to meet the design requirements of contrller,these parameters should be selected reasonably.