摘要
外界压力是影响高压电缆缓冲层烧蚀故障发展的重要因素。实际电缆的敷设条件以及缆芯重力会造成缓冲层受力不均匀,然而该不均匀性对缓冲层烧蚀故障发展过程的影响目前尚不明确。本文搭建了缓冲层不均匀烧蚀模拟实验平台,分别研究了干燥与潮湿条件下局部受力不均对缓冲层烧蚀发展过程的影响。然后结合缓冲层的局部体积电导率变化、微观形貌特征以及烧蚀产物成分,分析了受力不均匀性对烧蚀故障发展过程的影响机理。结果表明:在干燥条件下,缓冲层的电流密度随烧蚀时间逐渐衰减,受力集中部位的电流密度衰减速率更快;而在潮湿条件下,缓冲层的电流密度在烧蚀初期先急剧增加,随后迅速下降,呈现出电流密度尖峰特征,受力集中部位的电流密度尖峰的峰值更大,且尖峰内电流密度的变化速率更快。分析认为,局部受力集中会增大缓冲层半导电纤维之间的有效接触面积,导致电流密度上升,加剧烧蚀过程。
External force is the significant factor affecting the buffer layer ablation faults development of high voltage cables.The actual cable laying conditions and cable core gravity will lead to inhomogeneous force on the buffer layers.However,the influence of inhomogeneous force on the development process of buffer layer ablation faults is still unclear.In this paper,a simulating ablation experiment platform of buffer layers under inhomogeneous force was built.The influence of local inhomogeneous force on the buffer layer ablation development process was studied under dry and wet conditions.Then combining with the variation of buffer layer local volume conductivity,micromorphology and the components of ablation products,the affecting mechanisms of inhomogeneous force on the fault development were analyzed.The results show that in the dry condition,the current density of buffer layer decreases gradually with the ablation time,and the decreasing rate is higher in the force concentration region.While in the wet condition,the current density of buffer layer surges dramatically in the initial ablation stage,and then drops rapidly,exhibiting the characteristic of a current density peak.In the local force concentration region,the peak value of current density is larger,and the current density variation rate inner the peak is faster.It is analyzed that the local force concentration could increase the effective contact area between the buffer layer semi-conductive fibers,leading to the rising of current density and aggravating of ablation process.
作者
任志刚
郭卫
门业堃
陈平
高建
张浩然
李建英
REN Zhigang;GUO Wei;MEN Yekun;CHEN Ping;GAO Jian;ZHANG Haoran;LI Jianying(State Grid Beijing Electric Power Research Institute,Beijing 100075,China;Xi′an Jiaotong University,Xi′an 710049,China)
出处
《绝缘材料》
CAS
北大核心
2023年第8期80-86,共7页
Insulating Materials
基金
国家电网有限公司科技项目资助(5108-202218280A-2-353-XG)。
关键词
高压电缆缓冲层
不均匀受力
发展过程
导电路径
high voltage cable buffer layer
inhomogeneous force
development process
electrical conduction path
作者简介
任志刚(1983-),男(汉族),内蒙赤峰人,高级工程师,主要研究方向为高电压与绝缘技术、高压电缆;高建(1996-),男(汉族),辽宁大连人,博士生,主要从事先进电工材料、高压电缆领域的研究工作。
