Long-term assessment of a floating offshore wind turbine under environmental conditions with multivariate dependence structures
Long-term assessment of a floating offshore wind turbine under environmental conditions with multivariate dependence structures
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DOI：
10.1016/j.renene.2019.09.076
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发表时间：
2020-03
期刊：
影响因子：
8.7
通讯作者：
Xuan Li;Wei Zhang
中科院分区：
文献类型：
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作者：
Xuan Li;Wei Zhang
近年来，浮式海上风力发电机（FOWT）越来越多地用于获取持续高速的海上风力。在复杂的海上环境下，FOWT在其生命周期内会经历不同的环境条件和不同的发生频率。本研究采用C-vine (canonical vine) copula模型，建立了风向、风速、平均波向、有效波高、峰值谱波周期和波向传播6个风浪相关环境参数的依赖关系结构。使用不同的二元联结函数族作为构建块来模拟每对环境参数的相互依赖关系。然后，采用环境等高线法和Rosenblatt变换，按照规定的50年回归周期，确定了梁式FOWT关键位置的长期设计荷载。得到了五种不同结构响应的分形水平和乘法系数，为今后设计参数的选择提供指导。
Floating offshore wind turbines (FOWT) have been increasingly deployed to harvest the sustained high-speed offshore wind in recent years. Under the complex offshore environments, FOWT could experience significantly different environmental conditions with various occurrence frequencies during their lifetimes. In the present study, the dependence structure of six wind and wave-related environmental parameters (wind direction, wind speed, mean wave direction, significant wave height, peak spectral wave period, and wave directional spread) is established using a C-vine (canonical vine) copula model. Different families of bivariate copula are used as the building blocks to model the interdependence for each pair of environmental parameters. Thereafter, the environmental contour method and Rosenblatt transformation, according to a prescribed 50-year return period, are used to determine the long-term design loads at critical locations of a spar-type FOWT. Fractile level and multiplication factor are obtained for five different structural responses to provide guidance in parameter selections for future designs.