Study On Dynamic Characteristics Of Floating Wind Turbine Tower Based On Dynamic Boundary

After entering the 21 st century,with the rapid development of economy,energy shortage,environmental pollution and other problems are becoming increasingly serious,so we all pay attention to clean energy.Compared with people’s favorite land-based wind energy,it is not suitable for land-based research and development because of its large land-based wind energy reserve.In this paper,the 5MW three floating body wind turbine of the Renewable Energy Laboratory(NREL)of the United States is selected as the reference object,and a test model under dynamic boundary conditions is designed.150 different test conditions are carried out to study the dynamic characteristics of the wind turbine tower under different wind and wave conditions,and the dynamic response under different wind and wave conditions is simulated by fast software.Finally,the rationality of the test is analyzed by comparing the results of model test and numerical simulation.The specific research contents of this paper are as follows:(1)The research prospect and development of floating wind turbine at home and abroad are analyzed.The 5MW three floating wind turbine of renewable energy laboratory in the United States is selected as the research object.(2)Fast software is used to calculate the motion response of 5MW three floating body wind turbine under different wind and wave conditions.The time domain curves of tower top displacement,X,Y direction shear force and Z direction axial force are obtained.The time domain curves of platform motion under different wind and wave conditions are also obtained.The numerical results show that under the same wind speed and wave period,the X-axis displacement increases with the increase of wave height,and the X-axis and Z-axis shear forces increase with the increase of wave height.(3)Taking the overall parameters of 5MW floating wind turbine as the prototype,a1:30 scale test model is processed and made.A hydraulic cradle system is designed to replace the three floating platforms.By making the hydraulic cradle simulate the motion of the platform under the combined action of wind and wave,the motion of the wind turbine under the dynamic boundary condition is approximately simulated,and then the dynamic response of the tower with time is measured Finally,the stress amplitude variation of the tower in the test is compared with that in Patran calculation.The test results show that under the same wind speed,the x-axis acceleration at the upper end of the tower is always slightly larger than that in the tower,and increases first and then decreases with the increase of wave period.The X-axis and Y-axis stress of the tower increases gradually from the top to the bottom.In this paper,a dynamic boundary condition is constructed,and the dynamic characteristics of wind turbine tower under different wind waves are studied,which provides a reference for the engineering design of three floating body wind turbine.