基于雷电物理的风机叶片动态击距与电气几何模型

Dynamic Striking Distance and Electrical Geometry Model of Wind Turbine Blades Based on Lightning Physics

风机叶片遭受雷击现已成为风电场亟需解决的问题之一。该文将电气几何方法与雷电先导发展的物理过程相结合,提出了针对风机叶片的电气几何分析模型。通过引入风机叶片动态击距的概念及分析方法,模拟了雷电先导的发展过程,使得击距的物理意义更加清晰,并进一步推导了叶片防雷系统效率的计算方法,最后基于风机叶片长间隙下击穿实验验证了该模型的有效性。利用提出的风机叶片电气几何模型,分析了叶片角度、雷电流幅值和接闪器布置对防雷系统效率的影响,分析发现叶片越接近水平、雷电流幅值越小叶片防雷系统效率越低,增设叶片侧接闪器能够有效提高防雷系统效率。该文提出的方法拟为风机叶片的防雷设计与评估提供理论依据。

The damage of wind turbine blades suffered lightning strikes has been a key factor of the safe and reliable operation of wind farms. The electric geometrical model of wind turbine blades （EGMTB） was presented based on the traditional electric geometrical method and the physical process of lightning leader. The concept of dynamic striking distance was introduced and clarified the physical meaning of striking distance. And the calculation method of blade lightning protection system （LPS） efficiency was deduced. Finally, the effectiveness of EGMTB was validated by. the long gap breakdown experiment of blades. The EGMTB was used to analyze the influence factors of blade LPS efficiency. It is indicated that the efficiency of blade LPS reduces with the decrease of lightning current and the angle between the blade and horizontal, and the efficiency of blade LPS can be improved by increasing the side lightning receptors. The EGMTB is intended to provide a theory for lightning protection design and evaluation of wind turbine blades.