Influence of contact layer on the sulphur corrosion of copper conductors in power transformers  

作　　者：Lijun Yang Dong Ding Yuan Yuan Sihang Gao Yuncai Lu 

机构地区：[1]State Key Laboratory of Power Transmission Equipment and System Security and New Technology,Chongqing University,Chongqing,China [2]College of Material Science and Engineering,Chongqing University,Chongqing,China [3]Key Laboratory of Industrial Internet of Things and Networked Control,Ministry of Education,Chongqing University of Posts and Telecommunications,Chongqing,China [4]State Grid Jiangsu Electric Power Co.,Ltd.,Electric Power Research Institute,Nanjing,China

出　　处：《High Voltage》2022年第1期176-184,共9页高电压（英文）

基　　金：supported in part by the National Natural Science Foundation of China(Grant No.51677015 and 51907014);the Natural Science Foundation of Chongqing Province of China(Grant No.cstc2019jcyj‐msxmX0070).

摘　　要：Owing to the corrosive sulphides in the mineral insulating oil such as dibenzyl disul-phide(DBDS),copper windings in oil‐immersed transformers may suffer sulphur corrosion.This study investigates the influence of different contact conditions on the corrosion of copper conductors in transformers.Oil‐immersed accelerated corrosion experiment was conducted on copper conductors with various contact materials and different layers of insulating paper.The surface micromorphology,deposition compo-nent and the potentiodynamic polarization characteristics of copper conductors were explored.The results show that copper with different contact materials suffer sulphur corrosion;conversely,bare copper rarely does.It was also verified that the existence of a particular gap between copper and contact layer is a significant factor in sulphur corrosion by the formation of a concentration cell on the copper surface.The insu-lating paper wrapped around copper conductors does not increase the corrosion ten-dency of copper;however,it contributes to the formation of a region concentrated with DBDS,Cu^(2+),H^(+)by adsorption and impediment,which plays a key role in facilitating the sulphur corrosion of copper conductors.Moreover,sulphur corrosion can also occur on other metal parts in transformers when there is a particular gap on surfaces other than copper.

关 键 词：CORROSION COPPER SULPHUR 

分 类 号：TM41[电气工程—电器]