Numerical Study On Windsea Type Semi-submersible Floating Foundation With Three Pontoons Of Offshore Wind Turbine

Wind power has already formed important society, economic efficiency after years ofdevelopment. However the land resources are limited, wind power development from land tooffshore is an inevitable trend. Compared with advanced countries our country started offshorewind powder study very late, and we concentrate more attention in offshore fixed wind powerapplication, paying less attention to study on floating wind power relatively. A3×(3~3.6) MWfloating wind turbine system is designed according to the South China Sea conditions in this paper.Hydrodynamic performance of the platform structure, environmental movement response, mooringsystem design as well as the intact stability and damage stability are important research contents ofthis paper. And the following works are done.1. Referring to the Norwegian newest offshore floating wind turbine structures Windsearesearch，this paper designed a semi submersible floating structure form as well as pontoons andcolumns sizes depending on the basic elements of the wind power requirement and the calculatedupper aerodynamic loads. Then build the floating wind power system modals by use of GeniEmodule, applying to frequency domain, time domain analysis.2. This paper calculated hydrodynamic performance of the floating foundation by use ofHydroD module. Through optimizing the overall structural forms, sizes and the design of heaveplates, it requires the foundation installing three oblique wind towers simultaneously is superior tothe traditional semi-submersible floating foundation. At the same time, its main response times arefar from the South China Sea wave energy concentration periods, being suitable in South China Seaenvironment.3. This paper took the time domain analysis method to the floating wind power system underthe constraint of mooring system after the completion of importing hydrodynamic data into DeepCmodule, requiring that six degrees of freedom motion response of the system and cablestrength meet the offshore wind turbine operation safety requirements. A research on the ultimatecapacity of foundation was launched at the same time to obtain its maximum load capacity. 4. Stability of floating turbine platform is an important part of its performance index, the intactstability and damaged stability were studied to ensure the smooth running of windmills underoperating conditions and the survivability under extreme sea conditions when damage occurs.In relation to the semi-submersible floating platforms studied in home, the concept in whichthree oblique wind towers are installed simultaneously is some kind of innovation. Results of thestudy show that this kind platform performs better in hydrodynamic performance. The results intime domain indicate that the3×3MW wind turbine system can operate safely when significantwave height is no more than4.5m. Its maximum load capacity is3×3.6MW. All these providevalue reference for the research of floating wind power in future.