RVVB护套线弯折角度对过电流诱发短路故障的影响  

Influence of non-metallic sheathed cable’s turning angleon short circuit occurrence induced by overcurrent

作　　者：金运 李阳 余韬 郭鑫尧 闫奕欣 JIN Yun;LI Yang;YU Tao;GUO Xinyao;YAN Yixin(Graduate School,China People’s Police University,Langfang 065000,China;Institute of Forensic Science,China People’s Police University,Langfang 065000,China;College of FireProtection Engineering,China People’s Police University,Langfang 065000,China)

机构地区：[1]中国人民警察大学研究生院,廊坊065000 [2]中国人民警察大学物证鉴定中心,廊坊065000 [3]中国人民警察大学防火工程学院,廊坊065000

出　　处：《火灾科学》2023年第2期128-134,共7页Fire Safety Science

基　　金：中国人民警察大学校级科研重点专项项目(2019sycxpd001)。

摘　　要：RVVB护套线弯折处的内部导线应力有别于它处,发生过电流故障时,易在此处诱发短路故障。搭建了故障模拟电路,研究弯折角度α、电流值对短路发生过程、临界电流值、短路时间的影响。结果表明:相较于无弯折护套线,弯折的护套线发生过电流故障时,诱发短路故障的临界电流值降低了6 A(0.750Ie),即临界电流值I=4.125Ie;当I≤4.125Ie时,在所有测试角度下,护套线均不发生短路故障;当I=4.500Ie时,护套线仅在测试角度α=77°和84°诱发短路故障;当I≥4.875Ie时,在所有测试角度下均诱发短路故障,护套线弯折程度越大,诱发短路所需时间越短,且当I≥6.375Ie时,弯折角度对诱发短路时间的影响减弱,所有测试角度下诱发短路的时间趋于一致。研究结果可为电气火灾防治与调查提供基础数据。The turning angle of the non-metallic sheathed cable could change the stress distribution inside the cable.Theoretically,the different stress distribution is more likely to cause a short circuit on the overcurrent cable.In this work,the fault simulation circuit was conducted to study the effect of turning angle(α)on the current limit and required time under different overcurrent values.For a cable with various turning angles,compared to the horizontal cable(180°),the current limit with the turning situation decreased by 6 A(0.750 I e).A breakdown could be induced when the cable was at 4.125 I e.When the flowing current rose to 4.500 I e,a short circuit could occur at 77°and 84°.As this continuous luminous electric discharge,the circuit fault would inevitably be produced at 4.875 I e.A short circuit due to overcurrent might need less time if the cable was bent more.When the current increased to 6.375 I e,the time of short circuit occurrence at all testing angles had the same trend.With the current value increase,the impingement of the turning angle on the induced short circuit time decreased.This work provides information and data for electrical fire prevention and investigators to evaluate and identify the fire cause resulting from overcurrent cables.

关 键 词：电气火灾 故障转化 弯折角度 短路时间 

分 类 号：X93[环境科学与工程—安全科学] X932