特高压气体绝缘输电设备载流连接结构过热腐蚀特性  

Overheating Corrosion Characteristics of Electrical Connection Structure of UHV Gas Insulated Transmission Apparatus

作　　者：靳守锋 任汀 田汇冬 赵子辰 谢韬 王青于 刘鹏[1] 彭宗仁[1] JIN Shoufeng;REN Ting;TIAN Huidong;ZHAO Zichen;XIE Tao;WANG Qingyu;LIU Peng;PENG Zongren(State Key Laboratory of Electrical Insulation and Power Equipment(Xi’an Jiaotong University),Xi’an 710049,Shaanxi Province,China;State Grid Economic and Technological Research Institute Co.,Ltd.,Changping District,Beijing 102211,China)

机构地区：[1]电力设备电气绝缘国家重点实验室(西安交通大学),陕西省西安市710049 [2]国网经济技术研究院有限公司,北京市昌平区102211

出　　处：《电网技术》2023年第7期2985-2993,共9页Power System Technology

基　　金：国家自然科学基金项目(NSFC:52107163);电力设备电气绝缘国家重点实验室资助(EIPE21208)。

摘　　要：在特高压气体绝缘输电设备运行过程中,触指载流连接结构处容易因安装不当、载流不均而产生过热温度,加剧接触劣化,引发过热性故障。以气体绝缘设备中表带触指为研究对象,通过电热计算及红外温谱,确定触指过热范围,开展触指在SF_(6)、N_(2)、氮氧混合3种气氛下的过热腐蚀实验。利用扫描电镜、能谱分析对触指的接触形貌、腐蚀产物进行分析。结果表明,短时和长时大电流条件对接触电阻的影响相反。在铝电极组合和加速腐蚀48h内,3种气氛差异明显,纯氮气下接触电阻最低。在掺杂氧气、纯SF_(6)下接触电阻呈现波动、增长、稳定3个阶段,电阻最大值比氮气条件增长约14%。触指过热劣化机制主要为镀层高温剥落,基体暴露生成腐蚀产物。其表面氧、氟元素占比高,集中于触点。纯SF_(6)下触点及边缘腐蚀严重,铜银分界区存在明显的CuF、CuF_(2),与故障套管中触指表面形貌及产物较为相似,表明模拟实验的有效性。该研究可为气体绝缘输电设备中触指结构过热劣化分析提供依据。During the operation of the gas-insulated power transmission equipment,the connection structure of the contacts is prone to overheating due to improper installation and uneven current-carrying,which aggravates contact deterioration and causes an overheating failure.In this paper,the overheating temperature of the contacts is determined by electrothermal coupling and the infrared temperature spectrum.The high-temperature accelerated corrosion experiments of the strap contacts are carried out in three atmospheres of the SF_(6),the pure nitrogen,and the mixed nitrogen and oxygen.The contact morphology and corrosion products are analyzed by the electron microscope scanning and the energy spectrum analyzing.The results show that the short-term and the long-term high current have opposite effects on the contact resistance.For a specifically combined electrode and within 48h accelerated corrosion,the difference between the three atmaspheres is obvious with the lowest in the pure nitrogen.The overall contact resistance in the pure SF_(6) and the mixed gases presents three stages:fluctuation,deterioration,and stabilization,which is increased by about 14% compared with that under the pure nitrogen.Under the latter two atmospheres,the overheating degradation mechanism of the contact finger shows mainly the peeling of the coating at high temperatures,forming the corrosion products caused by the exposure of the substrates.The corrosion products on the contact surfaces have a high proportion of oxygen and fluorine,mainly concentrated in the contact area.The more serious corrosion degrees occur in the contact areas and the edges in the SF_(6) environment.There is CuF\CuF_(2) in the Cu-Ag boundary areas,similar to the surface morphology and products of the contact finger in the faulty bushing,indicating the validity of the simulation experiment.The research can provide a basis for the degradation analysis of the contact finger in the gas-insulated power transmission equipment.

关 键 词：气体绝缘输电设备 载流连接结构 接触电阻 腐蚀 过热劣化 

分 类 号：TM721[电气工程—电力系统及自动化]