摘要
高压开关柜内的绝缘件失效故障,易引发火灾事故、区域停电甚至影响电网系统的稳定运行。基于高压击穿电弧模拟与材料引燃机理综合模拟实验平台,针对4 mm厚支柱绝缘子和固封极柱,开展了15 kV击穿电弧作用下的系列引燃实验研究。结果表明,高压电极横向击穿后,电弧迅速上翻形成自上而下“夹持”样品的倒“U”形弧柱,弧根与弧顶首先炭化或引燃。阻燃绝缘件样品顶部形成火焰后,随着燃烧的进行,逐渐从顶部形成穿透样品的内部击穿电弧,该电弧易诱发剧烈燃烧的水平喷射火焰。内部击穿电弧位置向下移动呈“2阶段”特征:在初始阶段较慢,支柱绝缘子和固封极柱样品内击穿点下移速度分别约为2.55 mm/s和1.74 mm/s,而在第2阶段分别增大至78.50 mm/s和35.03 mm/s。此外,高压起弧瞬间,在紧邻电极上方的绝缘材料表面,升温速率可达180℃/s。研究结果可用于高压开关柜各类阻燃绝缘件的科学选型与优化设计,为开关柜防火安全性能的提升提供科学依据。
The failure caused by insulation invalidation in high voltage switchgear can easily lead to fire accidents and regional blackouts,and even affect the stable operation of the power grid system.An experimental setup is developed to simulate the high-voltage breakdown arc and material ignition mechanism.An experimental study on post insulators and embedded poles is carried out.The results indicate that after high voltage transverse breakdown of air,the arc moves up rapidly and forms an inverted"U"shaped that"clamps"the sample from top to bottom.The temperature of the root and top of the arc column is higher,and it tends to form carbonization or ignition first.After the flame is formed on the top of the flame-retardant insulation sample,the internal breakdown arc is gradually formed from the top of the sample during the combustion,which is easy to induce a horizontal jet flame.The downward movement of the internal breakdown arc position is characterized by"two stages".In the initial stage,the downward spread velocities of the breakdown point in the post insulator and embedded pole sample are 2.55 mm/s and 1.74 mm/s,respectively,while in the second stage,they increase to 78.5 mm/s and 35.03 mm/s respectively.In addition,at the moment of high-voltage arcing,the heating rate on the surface of the insulating material close to the electrode can reach 180℃/s.The results here can be used for the scientific selection and optimization design of all kinds of flame-retardant insulation in high-voltage switchgear and provide scientific support for improving the fire safety performance of switchgear.
作者
宋思齐
任美杰
李成钢
贾勇勇
谢启源
SONG Siqi;REN Meijie;LI Chenggang;JIA Yongyong;XIE Qiyuan(Electric Power Science Research Institute, State Grid Jiangsu Electric Power Company Limited, Nanjing 211103, China;State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei 230026, China;Research of Advanced Technology, University of Science and Technology of China, Hefei 230088, China)
出处
《火灾科学》
CAS
北大核心
2022年第1期15-24,共10页
Fire Safety Science
基金
国家电网有限公司总部科技项目(5500-202055065A-0-0-00J2020105)
国家重点研发计划项目(2020YFC1522800)
中央高校基本科研业务费专项资金(WK2320000043,WK2320000047)。
关键词
高压开关柜
阻燃材料
环氧树脂
电弧
引燃机理
High-voltage switchgear
Flame retardant materials
Epoxy resin
Electric arc
Ignition mechanism
