摘要
为研究高压电缆阻水缓冲层失效机理,尤其是其电化学腐蚀特性,对事故电缆缓冲层白斑进行成分分析,结合理论分析和模拟实验,确定白斑不同成分的产生机理。测试了缓冲层受潮特性,研究了缓冲层含水率和电流密度对其电化学腐蚀特性的影响。最后,基于电化学阻抗谱,测试了电化学腐蚀对缓冲层电气特性的影响,确定了缓冲层电化学腐蚀至最终烧蚀的演变规律。结果表明:阻水缓冲层由于受潮或电缆外破进水,会发生电化学腐蚀生成白斑(碳酸氢钠和氢氧化铝),并最终导致高压电缆失效;其腐蚀速率主要受电流密度影响,而最终腐蚀程度取决于阻水缓冲层的含水率。
In order to study the failure mechanism of water-blocking buffer layer in high voltage power cable,especially the electrochemical corrosion characteristics, we analyzed the composition of the white powders from failed cables, and confirmed the production mechanism of different composition in the white powders combining with theoretical analysis and simulation experiments. The moisture absorption characteristics of the buffer layer was tested, and the influence of the water content and current density of the buffer layer on its electrochemical corrosion characteristics was studied. Finally, based on electrochemical impedance spectroscopy, the influence of electrochemical corrosion on the electrical characteristics of the buffer layer was identified, and the evolution rule of the buffer layer from electrochemical corrosion to final ablation was determined. The results show that moisture ingress due to dampness or mechanical damage of the cable sheath causes electrochemical corrosion of the buffer layer and leads to the generation of white powder(consisting of NaHCO3 and Al(OH)3) and results in the final failure of the cable. The corrosion rate is closely related to the current density, while the final corrosion degree mainly depends on the moisture content of the buffer layer.
作者
郑建康
苏小婷
李庚
梁战伟
翟志辰
孔佳民
周凯
ZHENG Jiankang;SU Xiaoting;LI Geng;LIANG Zhanwei;ZHAI Zhichen;KONG Jiamin;ZHOU Kai(State Grid Shaanxi Electric Power Company Limited,Xi'an 710032,China;College of Electrical Engineering,Sichuan University,Chengdu 610065,China)
出处
《绝缘材料》
CAS
北大核心
2022年第2期91-96,共6页
Insulating Materials
基金
国家自然科学基金资助项目(51877142)。
关键词
高压电缆
阻水缓冲层
电化学腐蚀
high voltage power cable
water-blocking buffer layer
electrochemical corrosion
