Research On Risk Assessment Methods For Wind Farm Under Typhoon Conditions

Wind power generation is one of the most promising renewable energy technologies for future development.The"14th Five-Year Plan"states that China will vigorously develop wind power projects in the future.China’s long coastline has abundant wind resources and is an important area for the future development of wind power.However,China is also one of the countries most severely affected by typhoons.Typhoons often pose great risks to the structures of wind turbines and the power grid systems of wind farms.Therefore,conducting typhoon risk assessments for wind power plants is a necessary measure for the construction and maintenance of coastal and offshore wind farms.However,due to the scarcity of offshore wind measurement towers and the relatively short wind measurement time in wind farms for economic reasons,there is a lack of wind measurement data for coastal and offshore wind farms in China,which makes typhoon risk assessment for wind farms a major challenge.Therefore,this paper focuses on the research of typhoon risk assessment methods for coastal and offshore wind farms in China,and carries out independent research and development of software for the risk assessment of wind turbines in typhoon-affected areas for the first time.The specific research contents are as follows:Firstly,historical typhoon best track data of the Northwest Pacific provided by the Typhoon Data Center of China Meteorological Administration were extracted within the selected range of the Donghaitang Wind Farm from 1949 to 2021.To address the issue of the lack of typhoon data for the wind farm,this study introduced an engineering typhoon model to simulate the wind field of each historical typhoon,thereby obtaining the typhoon data of the wind farm under the influence of historical typhoons.Based on this,the typhoons were classified into different moving paths according to the different paths when passing through the wind farm.Furthermore,the typhoons in each path were further classified into leftward and rightward categories according to the different positions of the typhoon center when passing through the wind farm,and the historical typhoon characteristics of different paths of the wind farm were analyzed accordingly.Secondly,based on the principles of establishing risk assessment indicators,and after analyzing the typhoon risk characteristics of coastal and offshore wind power plants,this study selected four extreme typhoon disaster factors that have a significant impact on wind turbines by referring to various standardized specifications for wind power generation and existing research results(maximum wind speed value at the hub height under typhoon conditions(V_max),the longest duration of wind direction change(T_max),the maximum cumulative angle of wind direction change(Δθ_max),and the maximum rate of change of wind direction angle(ΔD_max))as the risk assessment indicators for wind power plants under typhoon conditions,and analyzed the distribution of historical typhoon disaster factors in the wind power plant.Finally,a comprehensive risk assessment index system for wind power plants under typhoon conditions was established based on four typhoon disaster factors as evaluation indicators.The weights of each level of indicators were calculated using the relevant theory of analytic hierarchy process.Then,the comprehensive risk assessment index of historical typhoons for different paths of the Donghaitang wind farm was calculated using the weights of each level of indicators.The natural breakpoint method was used to divide the typhoon risk levels of the Donghaitang wind farm,completing the historical typhoon risk level assessment.Based on this,a wind power plant typhoon risk assessment software was developed using the relevant contents and methods of this study,which provides strong support for the site selection,turbine selection,and typhoon risk assessment of coastal and offshore wind power plants in China.