Study On The System Parameters Optimization And Nonlinear Coupling Dynamics Of A Floating Wind-wave Power Generation Platform

There are abundant Marine renewable energies such as offshore wind energy and wave energy in China,which has become the main development direction of China’s future energy strategy actuate by our country’s carbon peaking and carbon neutrality goals.With the development of shallow sea wind power becoming increasingly saturated,the development of offshore wind power is gradually expanding into the deep sea.However,the harsh sea conditions of the deep sea put forward more stringent design requirements on the floating offshore wind turbine(FOWT)foundation,mooring system and submarine cables,which improve the unit power generation cost and reduce the safety and stability of the FOWT,and seriously restrict the development of the offshore wind energy resources.Meanwhile,wind and wave energy have strong symbiosis,and abundant wind energy are often accompanied by ample wave energy resources.In this context,the integrated wind-wave power generation technology has become the hot research topic in the area of offshore renewable energy.In this paper,the heaving constant parameter time domain model(CPTDM)of single Point absorber wave energy converter(PAWEC)is firstly constructed based on the Cummins equation with the time-consuming convolution terms replaced by StateSpace Model.The nonlinear dynamic response and power generation are analyzed under the action of end-stop system.Then,aiming at a floating wind-wave power generation platform(FWWP)combining a Floating offshore and a PAWEC,AnsysAQWA is used to investigate the influence of hydrodynamic interference between platform foundation and floater.With the viscous correction of the floater,the CPTDM of FWWP is established based on the CPTDM model of single floater considering the coupled effect of PTO and end-stop system.The nonlinear dynamic responses and wave power generation of FWWP and PAWEC are carried out under different end-stop system parameters,provide a basis for the selection of end-stop system parameters in subsequent calculation.Secondly,F2 A method is used to construct a fully coupled aero-hydro-servoelastic-PTO-mooring model of FWWP based on ANSYS-AQWA,which is compared and verified with the calculation results of FAST.On this basis,the coupled dynamic response of the floating wind-wave combined power generation platform is carried out under regular waves.The influences of PTO system coupling on the motion response and the power generation of the FWWP are explored.Furthermore,a series of parameter analyses were carried out on the wave period,wave direction and the mooring parameters of the oscillating floater.Finally,based on the fully coupled numerical model,the overall performance of the floating wind-wave combined power generation platform under irregular waves are investigated.The motion responses and power generation of FWWP in different wind speed and peak wave period are analyzed.Then,the motion response,power generation performance,mooring force,PTO force and end-stop force of the FWWP are investigated in operational and the extreme sea conditions with the introduction of end-stop system,respectively.The overall performances of FWWP are evaluated through the above analysis.In this paper,the influence of end-stop system parameters on the dynamic response and power generation are obtained through the nonlinear dynamic analysis of FWWP.The coupling dynamic response of the FWWP under the combined action of wind and wave is investigated.This study not only extends the application scope of floating offshore wind turbine and wave power generation devices,but also lay a preliminary numerical analysis foundation for the exploitation and utilization of the floating integrated wind-wave power generation platform,which has certain academic significance and engineering application value for the development of marine renewable energy and multi-energy complementary utilization.