摘要
皱纹铝护套结构的高压电缆近年来频繁发生缓冲层烧蚀故障,严重影响电缆的安全稳定运行。缓冲层烧蚀的机理、检测技术与解决方案在电力电缆领域得到了广泛关注。该文在阐述缓冲层结构及其功能的基础上,结合实际电缆的解体分析结果,从铝护套、缓冲层、绝缘屏蔽层、主绝缘层的角度,系统总结了烧蚀故障的典型特征。梳理了干燥与潮湿环境下缓冲层烧蚀的发展机理:在干燥条件下,烧蚀故障主要由电缆受力不均匀引发的局部电流集中所致;在潮湿条件下,除上述机制外,电化学腐蚀反应生成的高阻性白色粉末进一步加剧了电流集中现象,焦耳热持续累积,最终引发电缆结构的损伤。基于烧蚀特征及机理,讨论了各类烧蚀缺陷检测技术的适用性,包括基于烧蚀过程中物理信号变化、电缆结构变化及烧蚀产物的检测方法。此外,该文讨论了缓冲层烧蚀故障的解决方案:对于存量电缆,在烧蚀未伤及绝缘屏蔽之前可采取修复技术修复故障缓冲层;对于增量电缆,建议严格控制缓冲层杂质离子成分及含量、保证绝缘屏蔽与铝护套之间良好的电气接触,或采用平滑铝护套结构替代现有皱纹铝护套结构,从根本上预防烧蚀故障的发生。
In recent years,buffer layer ablative failure occurs frequently in high-voltage cables with corrugated aluminum sheathed structure,which seriously affects the safe and stable operation of cables.The mechanism,detection technology and solution of buffer layer ablation have been widely concerned in the field of power cable.On the basis of describing the structure and function of buffer layer,combined with the disintegration analysis results of actual cables,the typical characteristics of ablative faults are systematically summarized from the angles of aluminum sheath,buffer layer,insulation shield layer,and main insulation layer.The mechanism of buffer layer ablation under dry and wet conditions is summarized.Under dry conditions,ablation failure is mainly caused by local current concentration caused by uneven cable force.Under humid conditions,in addition to the above mechanism,the high-resistance white powder generated by the electrochemical corrosion reaction further aggravates the current concentration phenomenon,and the Joule heat continues to accumulate,eventually causing damage to the cable structure.Based on ablative characteristics and mechanism,the applicability of various ablative defect detection techniques is discussed,including detection methods based on changes of physical signal,cable structure during ablative process and ablative products.In addition,this paper discusses the solution of buffer layer ablative failure.For the stock cable,the repair technology can be adopted to repair the fault buffer layer before the ablative damage does not hurt the insulation shield.For incremental cables,it is recommended to strictly control the composition and content of impurity ions in the buffer layer,ensure good electrical contact between the insulation shield and the aluminum sheath,or replace the existing corrugated aluminum sheath structure with a smooth aluminum sheath structure to fundamentally prevent the occurrence of ablation failures.
作者
武康宁
赵鸽
李博达
葛洲
高建
任志刚
李建英
WU Kangning;ZHAO Ge;LI Boda;GE Zhou;GAO Jian;REN Zhigang;LI Jianying(State Key Laboratory of Electrical Insulation and Power Equipment(Xi’an Jiaotong University),Xi’an 710049,China;Guangdong Key Laboratory of Electric Power Equipment Reliability(Electric Power Research Institute of Guangdong Power Grid Co.,Ltd.),Guangzhou 510080,China;State Grid Beijing Electric Power Research Institute,Beijing 100075,China)
出处
《高电压技术》
北大核心
2026年第2期789-800,共12页
High Voltage Engineering
基金
国家电网有限公司科技项目(5108-202218280A-2-353-XG)。
关键词
高压电缆
缓冲层烧蚀
故障机理
故障检测
解决方案
high voltage cable
buffer layer ablation
failure mechanism
fault detection
solution
