Influences of Corrosive Sulfur on Copper Wires and Oil-Paper Insulation in Transformers

Energies

Jian Li¹  Zhiman He²  Lianwei Bao² 

[1] State Key Laboratory of Power Transmission Equipment& System Security and New Technology, College of Electrical Engineering, Chongqing University, Chongqing 400030, China;

关键词: corrosive sulfur;    copper wire;    copper sulfide;    thermal aging;    oil-paper insulation;    power transformer;   

DOI  :  10.3390/en4101563

来源: mdpi

【 摘 要 】

Oil-impregnated paper is widely used in power transmission equipment as a reliable insulation. However, copper sulphide deposition on oil-paper insulation can lead to insulation failures in power transformers. This paper presents the influences of copper sulfur corrosion and copper sulphide deposition on copper wires and oil-paper insulation in power transformers. Thermal aging tests of paper-wrapped copper wires and bare copper wires in insulating oil were carried out at 130 °C and 150 °C in laboratory. The corrosive characteristics of paper-wrapped copper wires and bare copper wires were analyzed. Dielectric properties of insulation paper and insulating oil were also analyzed at different stages of the thermal aging tests using a broadband dielectric spectrometer. Experiments and analysis results show that copper sulfide deposition on surfaces of copper wires and insulation paper changes the surface structures of copper wires and insulation paper. Copper sulfur corrosion changes the dielectric properties of oil-paper insulation, and the copper sulfide deposition greatly reduces the electrical breakdown strength of oil-paper insulation. Metal passivator is capable of preventing copper wires from sulfur corrosion. The experimental results are helpful for investigations for fault diagnosis of internal insulation in power transformers.

【 授权许可】

CC BY   
© 2011 by the authors; licensee MDPI, Basel, Switzerland.