海上风机叶尖曲率对接闪器防雷性能影响研究

Influence of Blade-Tip Curvature of Offshore Wind Turbine on Lightning Protection Performance of Receptor

长期处于高湿多盐雾恶劣环境的海上风机更需要可靠的雷电防护,叶片接闪器是风机防雷保护的重要措施,研究叶片结构对叶片接闪器防雷性能的影响具有重要意义。本研究通过建立3 MW海上风机全尺寸计算模型,考虑盐雾环境的影响,基于有限元法计算了雷电下行先导恰好到达风机模型雷击距时叶片表面的电场强度,确定了接闪器表面附近场强最大处为预测雷击点,通过已有实验数据对比验证了该模型的有效性。在此基础上,设计了叶尖和叶身两种接闪方式下的叶尖几何形态,通过分析不同叶尖曲率对接闪器性能的影响,得到了叶尖结构对接闪器拦截性能的影响规律。研究结果表明:随着叶尖曲率半径在一定范围内增大,叶尖接闪器的接闪性能先降低再升高,而叶身接闪器的接闪性能先升高而后降低,因此评估不同布置方式接闪器的接闪性能时,需要考虑叶尖的结构特性。

Offshore wind turbine in the harsh environment of high humidity and salt-fog for a long time needs more reliable lightning protection.Blade receptor is an important equipment for lightning protection of wind turbines.It is of great significance to study the influence of blade structure on the lightning protection performance of blade receptor.The author establishes a full-scale calculation model of 3 MW offshore wind turbine considering the influence of the salt-fog environment.The electric field strength on the blade surface when the lightning down-leader just reaches the lightning strike distance of the wind turbine model is calculated based on the finite element method,and the maximum field strength near the surface of the receptor is determined.It is used to predict the lightning strike point.The validity of the model is verified by comparing the existing experimental data.On this basis,the geometry of the blade-tip is designed under the two receptor modes of blade-tip and blade-body.By analyzing the influence of different blade-tip curvatures on the lighting attachment performance of receptor,the influence rule of the blade-tip structure on the lighting attachment performance of the receptor is obtained.The results show that as the radius of curvature of the blade-tip increases within a certain range,the lighting attachment performance of the blade-tip receptor first decreases and then increases,while the lighting attachment performance of the blade-body receptor first increases and then decreases.Therefore,when evaluating the lighting attachment performance of receptor with different replacement,it is necessary to consider the structural characteristics of the blade-tip.