Adaptation Of Semi-submersible Platforms To Large Wind Turbines And Analysis Of Motion Response

The TS7000 semi-submersible floating platform is a model of a semi-submersible platform designed by CIMC Raffles and located in shallow waters of the South China Sea.As the platform simulation calculation process does not take the wind turbine into account for the whole machine coupling calculation,it is of great significance to conduct a study on the wind turbine mating and the whole machine motion response after mating for this platform.First,the validity of the semi-submersible floating wind turbine calculation is analyzed using simulation tools.Using NREL 5MW-OC4 Deep Cwind semi-submersible floating wind turbine as a standard model,the validity of the FWO(FAST+Orca Flex)calculation of the wind turbine part is verified by comparing the aerodynamic response results based on the lobe element momentum theory and the control strategies of different stages of the wind turbine;after the hydrodynamic comparison analysis,the time domain motion response analysis of the whole floating wind turbine is carried out,and the validity of the FWO calculation of the whole wind turbine model is verified by motion After the hydrodynamic comparison analysis,the time domain motion response of the whole floating wind turbine was analyzed,and the effectiveness of the FWO model for calculating the whole floating wind turbine was verified through motion response comparison and mooring tension comparison.The TS7000 semi-submersible platform was then fitted with four large wind turbines of5 MW,6.2MW,10 MW and 15 MW respectively.Time domain response analysis was carried out using the four types of semi-submersible floating wind turbine under both power generation and extreme conditions.Based on the current safety standards for shallow water floating wind turbines and the realistic conditions of the platforms used,reasonable production and survival standards for semi-submersible floating wind turbine are developed to verify the feasibility and safety of the coupled model.Finally,the improved design of the floating wind turbine coupled model mooring system is carried out.Firstly,based on the control strategy of the wind turbine,different wind conditions are selected and time-domain simulation analysis is carried out to study the influence of the wind turbine load on the motion response of the floating platform;the suitable floating wind turbine model is determined and the initial mooring design is modified to study the influence of the mooring system on the motion response of the floating platform;through the improved design of the mooring system,it is ensured that The whole floating body system can meet the production and survival needs of wind turbine of 10 MW models and below.