新月形覆冰输电导线脱冰跳跃高度风载放大系数研究  

Study on amplification factor of jump height of crescent-shaped iced transmission conductor following ice shedding under wind action

作　　者：楼文娟[1] 张跃龙 黄铭枫[1] LOU Wenjuan;ZHANG Yuelong;HUANG Mingfeng(Institute of Structural Engineering,Zhejiang University,Hangzhou 310058,China)

机构地区：[1]浙江大学结构工程研究所,杭州310058

出　　处：《振动与冲击》2022年第21期272-278,共7页Journal of Vibration and Shock

基　　金：国家自然科学基金(51838012)。

摘　　要：导线脱冰产生的显著竖向振动可能会导致闪络跳闸等电气事故发生,从而危及电力传输。为了设计合理的电气绝缘间隙,需要准确估计导线脱冰后的最大跳跃高度,这不仅由脱冰产生的冲击作用决定,还可能受到风的影响。该文章研究了风载和脱冰对导线跳跃高度的耦合影响。开展了高频天平测力风洞试验并获得了不同厚度新月形覆冰导线的气动力系数。提出了用导线脱冰跳跃高度风载放大系数η来表征风的影响,在风速、覆冰厚度、风攻角及脱冰率等参数空间内,采用非线性有限元方法研究了该系数的参数敏感性,并拟合出了系数η的计算公式,可供设计使用。研究结果表明:在100°~150°风攻角下,风的作用会明显加剧导线脱冰跳跃高度,且随着覆冰厚度的增加,系数η呈现显著的非线性增加;系数η受脱冰率变化的影响较小,可以将其描述为给定风攻角下,关于风速和冰厚的函数。Significant vertical vibration caused by conductor ice shedding may lead to electrical accidents,such as,flashover tripping to endanger power transmission.Here,to design a reasonable electrical insulation gap,it is necessary to accurately estimate the maximum jumping height of conductor after ice shedding,this was not only determined by ice shedding impact action,but also might be affected by wind.Wind load-ice shedding coupled effects on conductor jumping height were studied.High frequency balance force measurement wind tunnel tests were conducted to obtain aerodynamic coefficients of conductors covered by different thicknesses crescent ice layers.Amplification factor η of wind load at jumping height of conductor ice shedding was proposed to characterize effects of wind.In parametric space of wind speed,icing thickness,wind angle of attack and ice shedding rate,the parameter sensitivity of the coefficient η was studied with the nonlinear finite element method,the calculation formula of the coefficient η was fitted and it could be used for design.The study showed that under wind attack angle of 100°-150°,wind action can obviously aggravate jumping height of conductor ice shedding,and with increase in icing thickness,the coefficient η has significant and nonlinear increase;the coefficient η is less affected by change of ice shedding rate,it can be described as a function of wind speed and ice thickness under a given wind attack angle.

关 键 词：新月形覆冰导线 脱冰 跳跃高度 脉动风荷载 脱冰跳跃高度风载放大系数 

分 类 号：TU398.9[建筑科学—结构工程]