摘要
架空地线断线事故严重影响电网的稳定运行,分析地线悬垂线夹内部的电流密度分布对研究发生在线夹内的断线机理具有重要的意义。首先建立接触部位的热路模型,分析了接触部位电流密度与其温升的关系;建立与实际接触点分布一致的地线悬垂线夹多接触点有限元仿真模型,并利用所建立的有限元仿真模型获取了线夹内部的电流密度分布;最后研究了预绞丝材料钢的相对磁导率对线夹内电流密度分布的影响。研究结果表明:在工频短路电流的作用下,发热瓶颈点位于地线悬垂线夹船体与绞线的接触界面外侧,此处电流密度值最大,温升也最高;钢的相对磁导率越大,线夹船体与绞线的接触界面外侧的电流密度越大,由此造成的温升也越高。
The ground wire breakage accident seriously affects the stable operation of power grid. It is of great significance to analyze the current density distribution within the suspension clamp of ground wire to investigate the mechanism of ground wire breakage within the clamp. Firstly,the thermal circuit model of contact region is established,and the relationship between current density of contact region and its temperature rise is also analyzed based on the thermal circuit model. Subsequently,combined with the distribution characteristics of contact points on the contact surface between the clamp and conductor,a finite element analysis( FEA) model based on multiple contact points of suspension clamp with the same actual contact points distribution is set up. According to the FEA model, current density distribution within the clamp is obtained. Finally,the effect of relative permeability of pretwisted steel on current density distribution within the clamp is studied. The results showed that hotspot is located at the outer edge of contact surface between the clamp hull and conductor. The current density and temperature rise are the highest in the hotspot. Moreover,as the relative permeability of steel increases,the current density of outer edge for contact surface between the clamp hull and conductor also increases,which results in higher temperature rise.
作者
杨睿
尹创荣
陈冠豪
刘贯科
吴勋
郭德明
郑文成
YANG Rui;YIN Chuangrong;CHEN Guanhao;LIU Guanke;WU Xun;GUO Deming;ZHENG Wencheng(Dongguan Power Supply Bureau of Guangdong Power Grid Co. Ltd.,Dongguan 523000,China)
出处
《智慧电力》
北大核心
2019年第4期118-124,共7页
Smart Power
基金
中国南方电网有限责任公司科技项目(GDKJQQ-20161036)~~
关键词
架空地线
悬垂线夹
接触点
热路模型
有限元分析
电流密度
overhead ground wire
suspension clamp
contact point
thermal circuit model
finite element analysis
current density
