论文部分内容阅读
风机叶片的雷电防护是风机安全运行的一个重要因素.为了研究风机叶片的雷击附着规律,通过对“云-地”线状雷电先导发展机理的分析,提出了一种基于静电场仿真分析的方法来确定雷击初始附着区域.建立了风机叶片以及下行先导的全尺寸模型,采取有限元法,运用3维电磁场仿真软件分析了雷电先导在风机叶片上的附着特点,优化了接闪器的布置方式,进而分析了叶片接闪器数量、大小对拦截效果的影响,并得出了叶片旋转过程中不同角度的雷击概率特点.研究结果表明:风机叶片叶尖位置雷击概率较高,接闪器布置应尽量靠近叶尖;当单个接闪器横截面积符合IEC 61400-24:2010标准规定的最小值50 mm2时,拦截效果最佳;增大接闪器横截面积及增加接闪器数量对于提高接闪器的拦截效果有限;叶片旋转角α小于45°时,易遭遇雷击,随着叶片旋转角增大,雷击概率逐渐降低,当α等于60°时,雷击概率降至最低.该研究结果可为进一步研究风机遭遇雷电时的电磁辐射特性提供依据.“,”Lightning protection of blades is important for the safe operation of wind turbines.In order to study the lightning attachment characteristic of blades,we proposed a method of electrostatic simulation to determine the lightning initial attachment zones by analyzing the development mechanism of the line lightning leader.Meanwhile,we established a full-size model of a blade and downward leader to investigate the lightning attachment characteristic by 3D electromagnetic simulation based on a method of finite element,and analyzed the configuration of receptors as well as the size and number of receptors on the effect of interception.Finally,we obtained the probability of the lightning strike during the rotation of blades.The research results show that the tip of a blade is more likely to be stroke.So it is suggested to place receptors as close as possible to the tip.The interception is more effective when the cross-section area of a single receptor is in accordance with the minimum value 50 mm2 recommended in IEC 61400-24:2010.The improvement of the effect of interception by enlarging the cross section area of the receptors or increasing the number of the receptors is limited.The blade is prone to being struck by lightning when the rotation angle α is less than 45 degree.With the increase of the rotation angle,the probability of lightning strike is gradually reduced.When the rotation angle α is equal to 60 degree,the probability of lightning strike is the lowest.The research achievement in this paper can provide meaningful reference to the lightning electromagnetic pulse characteristics of wind turbines.