架空输电导线不均匀脱冰跳跃高度计算  

Calculation of jump height for uneven ice-shedding of overhead transmission lines

作　　者：张宇卓 江岳 李小亭 周文武 谭浩文 张小力 孙清[1] ZHANG Yuzhuo;JIANG Yue;LI Xiaoting;ZHOU Wenwu;TAN Haowen;ZHANG Xiaoli;SUN Qing(School of Human Settlements and Civil Engineering,Xian University,Xi’an 710054,China;Northwest Electric Power Design Institute CO.,Ltd.,China Power Engineering Consulting Group,Xi’an 710075,China)

机构地区：[1]西安交通大学人居环境与建筑工程学院,西安710054 [2]中国电力工程顾问集团西北电力设计院有限公司,西安710075

出　　处：《振动与冲击》2023年第11期75-86,共12页Journal of Vibration and Shock

基　　金：国家自然科学基金(51978570);中国电力工程顾问集团西北电力设计院有限公司科技项目(XB1-DK04-2020)。

摘　　要：输电线覆冰在升温、自然风或人为外力作用下会发生覆冰整档或一档内部分位置脱冰,引起输电线跳跃,导致导线相间或导地线间闪络、线路跳闸、断股断线以及输电塔失稳倒塌等事故,严重威胁电力系统安全。参照实际750 kV输电线路工程,建立连续档分裂导线有限元模型,分析档数、档距、高差、覆冰厚度、风速、脱冰率和绝缘子串长度等因素对导线均匀和不均匀脱冰跳跃高度的影响;讨论均匀和不均匀两种脱冰方式下导线脱冰跳跃高度之间的联系,定义不均匀脱冰时发生脱冰的导线长度为换算档距;对比现有导线冰跳高度计算公式的准确性,提出不均匀脱冰跳跃高度系数。结果表明:当脱冰荷载相同时,不均匀脱冰引起的脱冰跳跃高度更大;不均匀脱冰时冰跳高度与换算档距下完全脱冰的冰跳高度存在一定比例关系;建立了导线均匀脱冰和不均匀脱冰跳跃高度计算公式,所提均匀脱冰跳跃高度计算公式的最大相对误差为11.8%,不均匀脱冰跳跃高度计算公式相对误差大于10%的结果仅占结果总数的13.2%,计算精度较高,有助于线路设计时确定相地或相间安全间隙。Under the effect of heating,natural wind or external force,the icing of the transmission line will fall off in the whole span or at a part of one span,causing the transmission line jumping.This leads to accidents such as flashover between wires’phases or ground wires,wire tripping,strands break,and the collapse of transmission towers,which seriously threatens the safety of the power system.In this paper,referring to the actual 750 kV transmission line project,a finite element model of continuous-span split conductors was established.The influence of the number of spans,distance between spans,height difference,ice thickness,wind speed,ice-shedding rate and insulator string length on the jump height caused by uniform and uneven ice-shedding of conductors was analyzed.The relationship between the jump height caused by the two ice-shedding methods was discussed,and the ice-shedding wire length in the case of uneven ice-shedding as the conversion span was defined.Comparing the accuracy of the existing calculation formulas for the jump height of conductors,a jump height coefficient for uneven ice-shedding was proposed.The research shows that:when the ice-shedding load is the same,the jumping height of the conductor caused by uneven ice-shedding is greater;there is a certain proportional relationship between the jump height during uneven ice-shedding and the jump height of complete ice-shedding under the conversion span;the calculation formulas of jump heights for uniform ice-shedding and uneven ice-shedding of conductors were obtained.The maximum relative error of the uniform ice-shedding jump height calculation formula proposed in this paper is 11.8%,and in a few cases,the relative error of the uneven ice-shedding jump height calculation formula is greater than 10%,which only account for 13.2%of the total number of results.It has a high calculation accuracy and helps to determine the phase ground or inter-phase safety gap in line design.

关 键 词：输电线路 数值模拟 不均匀脱冰 脱冰跳跃高度计算 

分 类 号：TM753[电气工程—电力系统及自动化]