输电铁塔在冰风耦合作用下失效概率分析

Failure probability analysis of transmission towers under ice-wind interaction

覆冰灾害严重威胁输电线路的安全运行。在冰灾过程中,往往伴随着风荷载的作用,为提高输电塔抵御覆冰灾害的能力,提出了一种基于Jones覆冰模型的输电铁塔失效概率评估框架。首先以湖南郴州、永州、邵阳3市气象站数据为基础建立了超级站,在此基础上利用Copula函数建立了考虑冰厚-风速、风速-风向相关性的联合概率分布,最后以一条实际输电线路为算例,计算了该线路铁塔在冰风荷载耦合作用下倒塌状态的失效概率。结果表明,提出的方法可以有效地评估输电塔在冰风耦合作用下的失效概率,考虑冰厚-风速、风向-风速相关性后,输电塔失效概率的计算更加科学合理。受风向概率的影响,输电塔失效概率的最大值出现的角度并不固定,该文章可为输电线路抗冰灾设计提供参考。

Icing disaster seriously threatens safe operation of transmission lines.In process of ice disaster,wind loads are often accompanied.Here,to improve the ability of transmission tower to withstand icing disaster,a failure probability assessment framework for transmission tower was proposed based on Jones icing model.Firstly,a super-station was established based on data from meteorological stations in 3 cities of Chenzhou,Yongzhou and Shaoyang,Hunan Province.Then,a joint probability distribution considering correlations of ice thickness-wind speed and wind speed-wind direction was established using Copula function.Finally,an actual transmission line was taken as an example to calculate the failure probability of this line’s towers collapse state under interaction of ice and wind loads.The results showed that the proposed method can effectively evaluate the failure probability of transmission towers under interaction of ice and wind;after considering correlations of ice thickness-wind speed and wind speed-wind direction,the failure probability calculation of transmission towers is more scientific and reasonable;due to effects of wind direction probability,the angle at which the maximum value of transmission tower failure probability occurs is not fixed;the study results can provide a reference for anti-ice disaster design of transmission lines.