谭志庆

摘要：

介绍了地线选择的原则.通过分析导线、地线不平衡张力杆塔受力情况发现，较短的地线金具应力调节能力差是严重覆冰中架空输电线路地线支架和地线受损的重要原因.通过对不同截面和强度的地线在不同覆冰情况下与导线的配合计算，以及对不同强度但相同截面地线的抗振分析，得出了在导线和塔头不变情况下增加地线截面和增加地线强度的可能性和优劣.最后得出，在中重冰区可以通过增加地线截面、增加设计覆冰、增加不均匀覆冰工况、提高地线钢丝强度等方式选择地线，并对实际输电线路设计中地线的选择提出了建议.

关键词：

地线； 不平衡张力； 过载能力； 覆冰厚度； 防振

中图分类号： TM 75文献标志码： A

Abstract：

Principles of ground line selection were introduced.By analyzing the unbalanced tension of conductor and ground line in pole tower，bad regulation ability of short ground lines and fittings played an important role in the damage of ground line and its stand in overhead transmission lines.Antivibration analysis of ground line with different intensities and same cross section as well as calculation of conductor and icing ground line with different crosssection or intensities showed the possibilities and merits of increasing the crosssection and intensity of the ground line without changes of conductor and tower head.At last，it could be concluded that the ground line could be selected in medium/heavy icing areas by increasing cross section，adding design icing，adding uneven icing，increasing the intensity of ground line.Suggestions were provided for the design of actual transmission line.

Keywords：

ground line； unbalanced tension； overload capacity； ice thickness； antivibration

2008年冬季，由于持续的雨雪冰冻天气，我国南方送电线路大面积覆冰，铁塔不堪重负倒塌断线，电力设施遭到前所未有的破坏，送电线路大范围中断.送电线路受灾现象表现为：地线及复合光缆驰度异常、直线绝缘子金具串线夹滑移、金具串损坏、地线或导线断线、光缆断芯线、塔材扭曲变形、铁塔地线尖子折断、导线横担折断和铁塔倒塌[1].但从送电线路受损的统计情况来看，每次冰灾天气，特别是2005年和2008年大冰冻时，地线支架和塔头损坏较多[2].

《110 kV～750 kV架空输电线路设计规范》[3]对地线的选择作了明确的规定，即按导线截面大小选配镀锌钢绞线作为地线.设计中无需进行地线选择，只有悬挂OPGW（通信光缆兼作地线……