覆冰导线动态风偏简化计算方法及影响因素分析

Simplified Calculation Method for Dynamic Wind-induced Deflection of Iced Conductors and Influencing Factor Analysis

以导线在自重和平均风荷载作用下的静力平衡构型和几何刚度为基础,采用GLE(阵风荷载包络线)法推导了输电线路的等效静力风荷载计算方法。针对常见的圆形覆冰导线,基于规范中的单摆模型并引入高差修正系数和等效静力风荷载,提出覆冰条件下输电线路动态风偏角的简化计算方法,并与有限单元法时域分析结果进行对比,检验了该简化算法的准确性。覆冰导线的风偏受覆冰密度、厚度和风速等多参数的影响,采用该简化计算方法对某实际线路进行覆冰风偏的参数化分析,结果表明:覆冰密度较小时,风偏角随着冰厚的增加先增大后减小;覆冰密度较大时,风偏角随冰厚的增加单调减小。相较于无覆冰时,多个覆冰工况的风偏角偏大,在设计时需引起重视。

Through static equilibrium configuration and geometric stiffness of conductors under gravity and mean wind load calculation method for equivalent static wind load of transmission conductors was derived by gust loading envelope (GLE) method. Based on simple pendulum model,simplified calculation method for dynamic wind-induced deflection of iced conductors was proposed by introducing elevation difference correction factor and then compared with time-domain analysis of finite element method to verify the accuracy of this simplified method. Wind deflection of the iced conductor is influenced by density,thickness,density and wind speed,parametric analysis of dynamic wind-induced deflection of a transmission line was conducted by using simplified calculation method,and the result shows that when the density of ice is comparatively small,the deflection angle firstly increases and then decreases with the ice thickness increment;when the density of ice is comparatively large,the deflection angle decreases monotonously with the ice thickness increment. Compared to bare conductors,the wind-induced deflection of iced conductors is relatively large,which should be focused in design.