森林火灾风险下的配电线路单相断线放电发展过程研究  

Research on the Development Process of Single-phase Breakage Discharge in Distribution Lines Under Forest Fire Risks

作　　者：权立 贺梦莎 张小庆 王毅钊 付钰伟 QUAN Li;HE Mengsha;ZHANG Xiaoqing;WANG Yizhao;FU Yuwei(Power Research Institute of State Grid Shaanxi Electric Power Company Limited,Xi’an 710100,Shaanxi Province,China;School of Electrical Engineering,Xi’an University of Technology,Xi’an 710048,Shaanxi Province,China)

机构地区：[1]国网陕西省电力有限公司电力科学研究院,陕西省西安市710100 [2]西安理工大学电气工程学院,陕西省西安市710048

出　　处：《全球能源互联网》2024年第1期55-65,共11页Journal of Global Energy Interconnection

基　　金：国网陕西省电力有限公司科技项目(5226KY 230003)。

摘　　要：随着台风、暴雪等极端恶劣环境的不断常态化,单相接地故障(如单相断线、单相击穿等)频繁发生,严重危害了电网安全。单相断线故障是引发森林火灾的常见故障之一,导线断线坠落至地面附近,在极短间隙内对地放电引燃地表附着的易燃物,最终引发森林火灾,对社会经济和自然环境危害严重。针对森林火灾风险下的配电线路单相断线对地放电发展过程研究建立短间隙放电模型,可以获得断口对地放电过程中的电场分布、电子平均能量分布、电子密度分布,以及不同断口外形对放电过程的影响机理。研究结果表明,随着断口半径从0.5 mm降至0.3 mm,流注头部的电场强度从80 kV/cm升高到110 kV/cm,电子平均能量从10 eV升高到11 eV,流注贯穿间隙时电子密度的最大值由1.5×10~(20)m~(-3)升高到2.7×10~(20) m~(-3)。断口半径越小、曲率越大,导致流注头部的电场强度和电子平均能量升高,流注头部电子密度和放电电流增加,更容易导致流注贯穿间隙。而断口不规则时由于具有更大半径,间隙击穿需要更长时间,因此放电电流峰值由9 A升高至15 A。如果考虑松针等含油量较高的地表附着物影响,该放电电流极易点燃地表附着物并形成电弧、引发火灾。该研究结果对于极端天气下的配电线路安全防护、预防森林火灾具有重要意义。In extremely harsh environments such as typhoons and blizzards,single-phase grounding faults(such as single-phase disconnection,single-phase breakdown,etc.)occur frequently,seriously endangering the safety of the power grid.Single-phase wire breakage fault is one of the common faults that cause mountain fires.Wire breakage falls near the ground,causing ground discharge in extremely short gaps and igniting flammable substances attached to the ground,ultimately causing mountain fires,posing serious harm to the social economy and natural environment.This article establishes a short gap discharge model for the development process of single-phase disconnection to ground discharge in distribution lines under forest fire risks,and obtains the electric field distribution,average electron energy distribution,electron density distribution,and the influence mechanism of different fracture shapes on the discharge process.The research results indicate that as the fracture radius decreases from 0.5 mm to 0.3 mm,the electric field intensity of the streamer head increases from 80 kV/cm to 110 kV/cm,the average electron energy increases from 10 eV to 11 eV,and the maximum electron density 20-320-3 increases from 1.5×10 m to 2.7×10 m when the streamer passes through the gap.The smaller the fracture radius and the larger the curvature,the higher the electric field intensity and average electron energy of the streamer head,the higher the electron density and discharge current of the streamer head,and the easier it is for the streamer to penetrate the gap.When the fracture is irregular,due to its larger radius,the gap breakdown takes longer,so the peak discharge current increases from 9A to 15 A.If considering the influence of high oil content surface attachments such as pine needles,the discharge current is highly likely to ignite the surface attachments and form an arc,causing a fire.The research results of this article are of great significance for the safety protection of distribution lines and the prevention of mountain fire d

关 键 词：山火放电机理 单相断线 流注放电 

分 类 号：TM771[电气工程—电力系统及自动化]