Hydrodynamic Response Analysis And Mooring System Optimization Of A Spar Floating Wind Turbine Platform

There are abundant wind energy resources in the ocean.But with the development and utilization of offshore wind power,offshore wind power planning has become increasingly saturated.Some developed countries are looking to the deep ocean.However,the offshore stationary wind turbine cannot be applied to the deep sea,so the research and design of floating offshore wind turbine(FOWT)is of great significance to the development of offshore wind power industry.In this paper,the background of the development of offshore floating wind turbine and the research status at home and abroad are summarized,several main technical challenges are put forward,and the method of dynamic response calculation of floating wind turbine is introduced.On this basis,combined with the wind turbine NREL-5MW,a spar type floating wind turbine platform is designed with reference to the characteristics and structural form of truss spar type offshore oil and gas platform,and its main performance parameters are also determined.The hydrodynamic analysis in frequency domain is also carried out to obtain the hydrodynamic coefficients,RAOs,second order force and so on.Then,the hydrodynamic performance is verified by comparing the time-domain motion response of truss spar type and typical spar type FOWT under typical operation condition.The extreme condition is selected to evaluate the safety of FOWT and mooring system.This paper also optimizes the traditional mooring system.By changing the layout of the mooring lines,the restoring moment of the mooring system on the pitch of the platform is increased to improve its control performance on the pitch motion.Compared with the traditional mooring system,the superiority of the system in pitch motion control is verified.In addition,the influence of optimal design of mooring system on each mooring line is analyzed from the aspects of strength and fatigue.In the end,the research work of this paper is summarized and conclusions are obtained,and the follow-up research work is prospected and discussed.