Experimental And Numbercal Study On The Dynamic Response Of Semi-submersible Offshore Wind Turbine System

As a clean and non-polluting renewable energy,wind energy makes an important impact for our country and the whole world's future sustainable development,especially,for the development of offshore wind energy,has a broad prospects.Nowadays,exploiting deep sea wind power by constructing semi-submersible wind turbine foundation becomes a main way of wind energy utilization.This paper focuses on two major goals: simulate the offshore floating wind turbine's response accurately and achieve the response control.Based on previous studies of our research group,this paper uses the FAST to simulate offshore floating wind turbine system response in various conditions.Our group also carried out a model test,to verify the accuracy of the simulation results.Finally,this paper designs a TMD system for our offshore wind turbine system.This paper does the refine study on three key points of the FAST simulation.And these three key points are our research group did not consider before,but in actual analysis,it is found that may have a significant impact on the results of numerical simulation: Introduce the calculation of second order wave forces;this paper also conducted a comprehensive analysis.And then consider the second order wave forces in the su bsequent numerical simulation of this paper;This peper design an spring mooring system substitute for catenary mooring system,and find the differences between catenary mooring system and spring mooring system in the dynamic performance;This paper amend the NREL-5MW wind turbine parameters,so that the data of basal thrust and base moment match the certain model 5 MW turbine's date.In order to verify the accuracy of the simulation results,our research group conducts a model test at the Joint Laboratory of Wind Tunnel and Wave Flume in Harbin Institute of Technology.This paper introduces the content of the experiment,and the test results and numerical simulation results are compared and analyzed.In order to make the wind turbine system our group desig ned can adapt to complex sea conditions,this paper design a TMD device for model LCP4.Through the establishment of a limited degree of freedom model,TMD device parameter optimization,and finally get the optimal parameters of TMD.The simulation results show that,after the installation of the TMD device,the fatigue characteristics of the wind turbine system are well controlled and the working time of the wind turbine system can be effectively extended.