架空导线单相触树接地故障的放电引燃机制研究  

Discharge Ignition Mechanism of Tree-contacting Single-phase-to-ground Faults of Overhead Lines

作　　者：秦际轲 宁鑫 范松海[2,3] 贾志东 QIN Jike;NING Xin;FAN Songhai;JIA Zhidong(Shenzhen International Graduate School(SIGS),Tsinghua University,Shenzhen 518055,Guangdong Province,China;State Grid Sichuan Electric Power Research Institute,Chengdu 610041,Sichuan Province,China;Power Internet of Things Key Laboratory of Sichuan Province(State Grid Sichuan Electric Power Company),Chengdu 610041,Sichuan Province,China)

机构地区：[1]清华大学深圳国际研究生院,广东省深圳市518055 [2]国网四川省电力公司电力科学研究院,四川省成都市610041 [3]电力物联网四川省重点实验室(国网四川省电力公司),四川省成都市610041

出　　处：《电网技术》2023年第3期1289-1298,共10页Power System Technology

基　　金：国家电网有限公司科技项目(52199921002U)。

摘　　要：近年来世界范围内因电气故障引发森林火灾的案例时有发生,严重威胁到民众的生命财产安全。该文针对架空导线单相触树引燃植被的事故,分析了高压电场作用下植被的引燃机制,并建立树线接触模拟试验平台,得到植被引燃过程中典型的物理特征和电气特征。结果表明:1)放电引燃过程可分为4个典型的阶段并和泄漏电流的变化相对应;2)电流持续导通时间和初始电流是决定引燃能否发生和发展的关键;3)接触部位和炭化通道上的电弧能促进火焰的发展,并导致植被绝缘能力进一步下降;4)引燃过程中存在“炭化效应”和“烹饪效应”的博弈,这种竞争导致电气信号在时域发生变化;5)炭化通道呈典型的电树枝状,树枝中的导电通道集中于表皮和主干的交界面处。从试验结果可知,高压电场下的植被引燃有阶段性发展的特点,分析放电引燃的机制,准确提取并识别植被燃烧各阶段特征,将有助于改善故障检测技术。In recent years, forest fires have areoccured frequently caused by electrical faults all over the world, which seriously threaten people’s life and property safety. Aiming at the accidents of vegetation ignition caused by the treecontacting sin-gle-phase-to-ground faults of the overhead lines, a tree-line contacting simulation test platform was established, and the ignition mechanism of vegetation under a high voltage electric field was analyzed based on the typical characteristics of vegetation ignition process in the test. The Rresults surfaceindicate: 1) The process of discharge ignition can be divided into four typical stages corresponding to the changeing characteristics of electricalcurrent leakage characteristics;2) Cumulative The continuous current conduction time and the initial current are the keys to determine whether the ignition canmay occur and how it develops;3) The arcs inat the contacting areapoint and in the carbonization channel canmay promote the development of flames and further reduce the insulation ability of the vegetation;4) There is a game between the "carbonization effect" and the "cooking effect" happening in the ignition process, which leadsing to the change of electrical signals in time domain;5) The carbonization channels arepresent the typical shape of electrical dendritice, and thewhose conductive channels in the dendrites are concentrated aton the interfaces between the epidermis and the trunk. According to the test and analysis, the vegetation ignition under a high voltage field has the characteristic of stage development. Accurately extracting and identifying the characteristics of vegetation combustion in different each stages of vegetation combustion will be helpful to improve the technology of fault detection technology.

关 键 词：导线触树故障 炭化通道 电弧 引燃过程 山火 

分 类 号：TM721[电气工程—电力系统及自动化]