中冰区输电线路悬垂塔地线不平衡张力取值研究  

Discussion on the Unbalanced Tension of Transmission Line Suspension Tower Ground Wire in Medium Icing Area

作　　者：张小力 周文武 赵丹 齐忠堂 沈巍巍 李静波 ZHANG Xiaoli;ZHOU Wenwu;ZHAO Dan;QI Zhongtang;SHEN Weiwei;LI Jingbo(Northwest Electric Power Design Institute Co.,Ltd.of China Power Engineering Consulting Group,Xi’an 710075,Shaanxi,China;State Grid Economic and Technological Research Institute Co.,Ltd.,Beijing 102209,China)

机构地区：[1]中国电力工程顾问集团西北电力设计院有限公司,陕西西安710075 [2]国网经济技术研究院有限公司,北京102209

出　　处：《电网与清洁能源》2023年第1期37-42,51,共7页Power System and Clean Energy

基　　金：国家电网有限公司科技项目(SGTYHT/18-JS-206);西北电力设计院有限公司科技项目(XB1-DK04-2020)。

摘　　要：采用“等线长法”计算中冰区悬垂塔地线在不均匀覆冰下不同档数、档距、高差、档距差、串长和应力情况下的不平衡张力,并结合具体工程实例,分析现有规程规范的局限性。结果表明:对于地形条件较差的山区线路,不均匀覆冰下中冰区地线不平衡张力比较容易超规程限值,且不平衡张力受中间档档距差或高差的影响较小,受档距或连续变化档距差的影响较大;为减小输电线路纵向不平衡张力,应缩短耐张段长度或减少档数,缩小使用档距,增加悬垂串长或电线应力,均匀分布档距;由于提高地线纵向不平衡张力百分数对塔重和工程造价的影响较小,建议15 mm中冰区悬垂塔地线不均匀覆冰下不平衡张力提高至40%,20 mm中冰区提高至45%。Based on the constant conductor length,the unbalanced tension of the ground wire of the suspension tower in the ice area under the condition of non-uniform accreted ice and different span numbers,span lengths,height differences,span length differences,string lengths and stresses was calculated.The limitations of existing regulations and specifications were analyzed combined with specific engineering examples. The results show that the unbalanced tension of the ground wire in the middle ice area under uneven icing is easy to exceed the specification limit. The middle span difference and height difference have little influence on the unbalanced tension,but the span length and continuous change span difference have great impacts on the unbalanced tension. In order to reduce the unbalanced tension of transmission lines,it is necessary to reduce the length or number of spans in the tensile section,reduce the span length,increase the string length or wire stress,and evenly distribute the spans in the tensile section as far as possible or take measures such as increasing first and then decreasing the spans. Because increasing the percentage of unbalanced tension of ground wire has little effect on tower weight and project cost,it is suggested that the unbalanced tension of suspended tower ground wire under uneven icing in 15mm middle ice area be increased to 40 %,and that in 20 mm middle ice area be increased to 45 %.

关 键 词：中冰区 不均匀覆冰 不平衡张力 地线 输电线路 

分 类 号：TM726[电气工程—电力系统及自动化]