Design And Dynamic Response Analysis Of Multi-column Spar Type Floating Wind Turbine Platform

With the construction and planning of offshore wind power becoming more and more saturated,the developed countries in the world focus their development of wind power resources on the deep-sea.Deep-sea floating platform design and motion performance research has become a research hotspot in various countries.The United States,Norway and other countries have developed many floating wind turbine platform and put them into use,they are in the world's leading position.Research on offshore floating wind turbine platforms in China,especially deep-sea floating wind turbine platforms,is still in the preliminary stage.The multi-column Spar floating wind turbine platform was studied in this paper draws on the advantages of Cell Spar platform and Truss Spar platform.The mooring system of the platform uses a radial distributed mooring mode of eight rectangular semi-tension mooring cables.The theoretical analysis and numerical simulation methods are used to analyze the platform hydrodynamic performance and motion response in frequency and time domain.Modeling of the multi-column Spar-type floating wind turbine platform is implemented via UG and ANSYS.Three-dimensional potential flow theory is used to analyze the hydrodynamic and kinematic properties of the platform,the hydrodynamic parameters such as the wave load acting on the platform and the transfer function of the platform motion response was Calculated,a short-term forecast on the movement of platform in irregular waves was made.The results show,the natural frequencies of the designed platform in all directions are far away from the wave conditions in the South China Sea.Platform has good resistance to wave and sports performance,the obtained frequency domain calculation result can be used for the time domain coupling calculation.Various non-linear factors such as mooring systems are added to the coupling analysis.Considering the combined effect of regular waves,winds and currents,and considering irregular waves,winds and currents under the extreme sea conditions in the South China Sea,the motion response of the platform and the change of mooring line tension were analyzed by three-dimensional nonlinear time-domain simulation.The results show that the platform response and the tension of the Cables meet the requirements of the specification under extreme ocean environment.The multi-column platform is compared with the single-column platform in time domain response under extreme sea conditions.The multi-column platform is better than single-column in overall motion response,however,the pitch response is larger than the single column platformIn summary,the new multi-column Spar floating wind turbine platform designed in this paper has good hydrodynamic performance.Multi-column platform in the extreme sea motion response meets regulatory requirements,has anti-typhoon capabilities.Compared to single-column,the hydrodynamic performance of multi-column platform is better.This paper can provide a reference for the design of bathyal sea floating wind turbine platform in South China Sea.