考虑二维等效静力风荷载的导线风偏刚性直棒法

Rigid rod method for wind-induced swing response of transmission conductors considering two-dimensional equivalent static wind loads

刚性直棒法作为一种简单高效的输电导线风偏响应估算方法,在输电工程领域得到了广泛的应用,然而其适用对象仅限于水平风作用下的未覆冰导线,对于线路常遇的覆冰以及二维风荷载情况未能涉及。该文采用阵风荷载包络线法(GLE法)推导了二维等效静力风荷载的表达式,获得了考虑二维风荷载作用的导线风荷载调整系数,通过引入二维等效静力风荷载改进了现有刚性直棒法,改进后的刚性直棒法综合考虑了线路是否覆冰、二维风荷载、上升气流以及风的脉动效应。建立了某真型输电线路的精细化有限元仿真模型,采用覆冰导线气动力风洞试验结果和非线性数值仿真验证了改进后刚性直棒法的准确性。基于改进后的方法分析了竖向平均风速和导线覆冰厚度对风偏响应的影响。研究表明:考虑二维等效静力风荷载的导线风偏刚性直棒法是一种准确度明显提高的通用方法,能适用于常规的、覆冰的、有上升气流的多种工况下的导线风偏位移计算。

As a simple and efficient method for estimating the wind-induced swing response of transmission conductors,the rigid rod method has been widely applied to the field of power transmission engineering.Its applicability,however,is only limited to bare conductors under the influence of horizontal winds,and it hasn't been applied to conductor icing and two-dimensional wind load cases.In this work,the expression for the two-dimensional equivalent static wind loads is derived using the gust loading envelope method(GLE).The dynamic wind load factor of the conductor considering the effect of two-dimensional wind load is obtained.The existing rigid rod method is improved by introducing two-dimensional equivalent static wind loads,taking into account ice-accretion,two-dimensional wind loads,updrafts,and fluctuating wind.A refined finite element simulation model for a practical transmission line is established,and the accuracy of the improved rigid rod method is verified based on wind tunnel test results and nonlinear numerical simulations.Based on the improved method,the effects of mean vertical wind speed and conductor ice thickness on the swing response of transmission conductors are analyzed.The research results show that the improved method considering the two-dimensional equivalent static wind loads is a general method for conductor swing response calculation with significantly higher accuracy,and the improved method can be applied to the calculation of wind-induced swing of conductors under conventional,ice-accreted and updraft conditions.