覆冰导线设计中的三类复杂问题的探讨

Discussion about 3 Kinds of Complicated Issues in Iced Conductor Design

针对现行架空线设计规范,研究了覆冰影响导线安全的3类复杂问题:一是覆冰和导线粘结在一起,应作为复合材料计算其弹性模量;二是覆冰使导线荷载增加的同时会引起导线的局部刚度增加,使导线受到应力增加的双重效应,在一定的风力作用下,导线的摆动使覆冰脱落或断裂,进而引起导线的刚度突变,从而引起应力突变与集中:三是架空线的局部受力和低温冷脆问题。通过对3类问题的探讨,指出覆冰脱落是导致倒塔主要客观原因。

Pointing to current design specifications of overhead lines, the paper studies 3 kinds of complicated issues related to icing impact on conductor safety： （1） ice binding on conductor should be taken as a compound material to calculate its elastic module; （2） icing adds conductor load and partial stiffness at same time, which results in double stress addition for conductor; and under certain wind effect conductor swing motion causes ice shedding or breakage, which results in sudden stiffness change of conductor, as a resuh, stress sudden change and concentration; （3） overhead line partial stress applied and low temperature cold shortness. The paper points out that ice shedding is the main objective cause for tower collapse through discussion about previous 3 issues.