The Study Of Offshore Floating Wind Turbine On A Tension Leg Plateform

Wind energy is rich in the sea, and wind power generation could provids renewable andclean energy. Now it is inevitable that offshore wind turbine develops from shallow pilestyle to deep floating style, and it has become the focus field in foreign countries, but it isstill at the initial stage in our country. Floating support structure is very important forfloating offshore wind turbine, but many domestic researches remain at traditional fixedstructure style of coastal water due to lack of mature design standard and analysis software.Therefore, it’s necessary to promote the research of key technology about the supportstructure of floating offshore wind turbine.According to IEC-61400-3specification (International Electrotechnical Commission<design requirements of offshore wind turbine>) and the offsore floating platform relatedspecification of DNV, a concept design of a support structure of a floating wind turbinebased on TLP in sea area is conducted and its mechanical properties is studied in the paper.Key research contents and relevant conclusions in this paper are as follows:(1) A concept design of the support structure of a floating wind turbine based onTLP in sea area is done. Through the analysis of different types of platforms, the supportstructure of the floating wind turbine based on TLP is selected, and its main size isdefinited; Meanwhile, the stability and the motion performance are calculated, and its mainperformance index meets the require through the analysis.(2) The dynamic response of the whole structure of the support structure of afloating wind turbine based on TLP in sea area is studied. A finite element model with fullycoupled integration of the whole structure of the support structure of the floating windturbine based on TLP in sea area is built, and its natural frequency could well avoidexcitation frequency of THE wind turbine and the main wave frequency. Then the differentresponse parameters are studied through the analysis of time domain coupling under theload of wind and the wave load. At last, the influence of different wind speed and differentwave height are studied through the spectral density function. The Wind load is moreimportant than wave load for the support of floating wind turbine.(3) The hydrodynamic performance of the whole structure of the support structure ofa floating wind turbine based on TLP in sea area is studied. Its hydrodynamic coefficientunder frequency domain is calculated, and the RAO of the first-order wave exciting forceand the six degrees of freedom motion response are studied. A danger range of the wave frequency of the support structure is obtained. Meanwhile, the parameters of the pretensionof the tension leg, the lengthof the the tension leg and the number of the tension of tendonsinfluence on the motion response are studied. At last, its short and long term forcasts arecalculted.(4) The structure design of the whole structure of the support structure of thefloating wind turbine based on TLP in sea area is studied. The coefficient of load underdifferent ultimate states are selected with design method of resistance partial coefficients ofloads, and the design load of different part of the floating support structure is determined.Its minimum design plate thick and the minimum section modulus of stiffener and girderare obtained.(5) The wave load analysis of the whole structure of the support structure of thefloating wind turbine based on TLP in sea area is studied. Its typical profile loading, itstransfer functionand and its long term statistical value are calculated, and the related designwave parameter is obtained.(6) The whole strength analysis of the whole structure of the support structure of thefloating wind turbine based on TLP in sea area is studied. Its finite element model is built,and the strength calculations of the overall under different load are calculated. The sectionof high stress is discussed, and the advices of the modied plans are provided.(7) A demo model and a test model of reduced-scale model of the whole structure ofthe support structure of the floating wind turbine based on TLP in sea area are designed,and the testing program is conducted. The measurement of the characteristic of motionresponse under the combine of wind load and wave load are planned. Moreover, theinfluence of the analogy methods of wind load on motion response of the floating supportis to be studied.