半潜式浮式风机长期动力响应的全局敏感性分析

Global Sensitivity Analysis of Long-Term Dynamics of Semi-Submersible Floating Wind Turbines

开展下部结构优化设计是降低浮式风机度电成本的有效途径。下部结构设计涉及多个尺寸参数。通过全局敏感性分析,可以将与动力学性能相关联的尺寸参数识别出来,实现降低设计空间维度,提高优化设计效率的目的。基于概率密度的敏感性分析方法,文章量化了Y形半潜式风机长期动力响应对9个尺寸参数的敏感程度。结果表明:对于平台倾角、机舱加速度、塔底疲劳损伤,立柱半径是最重要的尺寸参数,而平台吃水深度和立柱间距次之。增大立柱半径有利于改善平台稳性,抑制平台倾角,但同时也会增大平台的水动力荷载,加剧塔底、导缆孔疲劳和机舱加速度响应。导缆孔疲劳对索链直径最为敏感。研究可作为选取下部结构尺寸优化变量的依据。

Carrying out substructure optimization is an effective way to reduce the levelized cost of energy(LCOE)of floating wind turbines(FWT).Substructure design involves a considerable number of dimension parameters.Through global sensitivity analysis,the dimension parameters associated with dynamic performance can be identified to achieve the purpose of reducing the design space dimension and improving the efficiency of optimization.The study evaluates the sensitivity of long-term dynamic response of a Y-shaped semi-submersible FWT to nine dimension parameters by using the density-based sensitivity analysis approach.The column radius is found to be the most important parameter for platform tilting angle,nacelle acceleration and tower base fatigue damage,followed by the platform draft and column spacing.Increasing the column radius is conducive to improving the stability and restraining the platform tilting angle,but it also increases the hydrodynamic loads,leading to the higher tower base and fairlead fatigue and nacelle acceleration.The fairlead fatigue is most sensitive to chain diameter.The study can serve as the basis for selecting the design variables for substructure optimization.