摘要
为研究RVVB导线过电流诱发短路故障的发生过程和熔痕典型特征,搭建220 V电压条件下的导线过电流诱发短路故障电路,利用高速影像分析短路发生过程,统计初次短路发生时间和持续拉弧次数,收集线芯熔痕并分析其典型特征。结果表明:导线由内及外受热时,逐渐炭化以致失效,导线发生初次短路时间与电流值存在指数递减关系,最短初次短路时间为46 s,I≥48 A时导线发生持续拉弧的试验组数增多,持续拉弧向电源侧移动,同组试验最多为13次,线端熔痕金相组织主要为粗大的柱状晶,电弧熔珠多为树枝晶和等轴晶。试验结果可为起火原因认定提供基础数据。
In this paper, the occurrence process of RVVB over-current induced short-circuit fault and the typical characteristics of weld marks are studied. Based on the simulation of a short-circuit fault induced by over-current of power line under 220 V voltage, the short-circuit occurrence process is analyzed by using high-speed images, the initial short-circuit occurrence time and continuous arc striking times are counted, and the core weld marks are collected to analyze their typical characteristics. The results show that: when the wire is heated from the inside, it is gradually carbonized and become useless;the initial short-circuit time of the wire is exponentially decreasing with the current value and the shortest initial short-circuit time is 46 s;when I≥48 A, the number of the arcing wire in the experimental groups increases and the continuous arcing moves to the power source side;the number of experiments made among the same group is up to 13 times, and the metallographic structure of the wire end weld marks is mainly bulky cylindrical crystal, the arc melting beads are mainly branch and isometric crystal. The results can provide basic data for identifying the cause of fire.
作者
李朝阳
赵彬岐
LI Chaoyang;ZHAO Binqi(Law,Regulation and Resources Division,Guizhou Fire and Rescue Brigade,Guiyang,Guizhou Province 550000,China;School of Fire Protection Engineering,China People’s Police University,Langfang,Hebei Province 065000,China)
出处
《中国人民警察大学学报》
2022年第10期19-23,共5页
Journal of China People's Police University
关键词
电气火灾
过电流
短路故障
熔痕特征
electrical fire
over-current
short-circuit fault
characteristics of weld marks
