| Nowadays,most offshore wind farms in the world are located in coastal areas and tidal flat areas.The coastal areas and tidal areas that can be developed gradually reduce because the wind farms are mostly distributed in blocks and cover a large area.Therefore,offshore wind power projects will inevitably move from coastal areas to open seas.Compared with coastal areas,the open seas have more abundant wind energy resources,more stable wind speed,and will not conflict with the sea fishing grounds,air routes,etc..So the development and construction of offshore wind farms in the open seas have become a research focus of China and the international offshore wind power industry.However,with the development of offshore wind farms moves to the open sea,the Marine environment is worse and the loads of wind turbines are more complex.Therefore,comprehensive assessment of wind energy resources and Marine environment is needed.Traditional offshore wind tower has been unable to adapt to the development trends of offshore wind farm because of the high construction cost,measuring limited functionality,so this article combined the technology of wind lidarand ocean data buoy technology,puts forward a new type of floating lidar wind measurement system,which can be better applied to the assessment of wind energy resources and Marine environment in the early stage of offshore wind farms.The main research contents of this paper are as follows:1.According to buoy the working environment and measurement requirements,Selecting the main measuring equipment and determine the weight,volume and technical requirements of each equipment.The design of six subsystems including lidar system,data storage and communication system,power supply system,auxiliary measuring equipment and mooring system was carried out in combination with the relevant foreign guidance documents.Then,on the basis of typical buoy design at home and abroad,different design schemes of the buoy body are put forward.Finally,the floating lidar system is designed,and the general arrangement,main scale parameters and technical characteristics of the system are determined.The results show that the floating lidar system not only has good hydrodynamic and stability performance,but also can ensure the system to operate independently in the harsh Marine environment for a long time.2.According to the buoy structure determined above,the hydrodynamic calculation model of the buoy is established.The AQWA software are used to calculate the hydrodynamic performance of the buoy,and the first-order wave force,second-order wave force,additional mass and additional damping coefficient of the buoy in the frequency domain are obtained.The results show that the buoy has good wave resistance and hydrodynamic performance,and the natural frequency of the buoy can avoid the main frequency range of the wave,and the calculated results in the frequency domain can be used for the following time-domain coupling analysis.3.The multi-point tension mooring system and multi-point catenary mooring system are designed in this paper.Considering the effects of wind,wave and current,the time-domain analysis method is used to compare and analyze the motion response and mooring cable tension of the buoy under two mooring systems.The analysis results show that the multi-point tension mooring system has better motion control ability to the buoy,and the safety coefficient of mooring cable tension meets the requirements of relevant specifications,so the multi-point tension mooring system is determined.4.According to different operating sea conditions and water depth conditions,9calculation conditions were determined.The time-domain coupling analysis of the buoy and its mooring system is carried out,and the movement response and time-history curves of the buoy under different working conditions and mooring cable tension are obtained,and the calculated results are statistically analyzed.Then,the characteristics of buoy’s motion response and mooring cable tension under extreme sea conditions are analyzed. |
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