Summary

The pressboard/oil interface in transformer insulation is very vulnerable to creeping discharge. Therefore, the influences of thermal ageing of pressboard on the creeping discharge at pressboard/oil interface have been studied in the present contribution. Using a needle-plate electrode, long-term tests were carried out with differently-aged pressboard samples under constant voltages of 34 kV and 36 kV, respectively. The PD number and the average magnitude of PD pulses have been analysed to study PD activities of various test samples under different voltages. Moreover, it was found that the carbonization area is inversely proportional to the ageing degree of pressboard and the formation of white mark was jointly determined by the degree of thermal ageing and the intensity of electric field. The carbonized pressboard can still withstand the applied voltage for a comparatively long time, whereas the pressboard with white marks will flashover soon due to the bubbling effect. Lastly, the nature and influential factors of carbonation and white mark have been also discussed.

Additional informations

Publication type ISH Collection
Reference ISH2015_164
Publication year 2015
Publisher ISH
File size 812 KB
Price for non member Free
Price for member Free

Authors

Kikuchi Yusuke, Nagata Masayoshi, Li Chong, Hochmuth Harald, Samusenko Andrey

The Influence of Thermal Ageing on the Electrical and Physiochemical Properties of Pressboard/Oil Interface
The Influence of Thermal Ageing on the Electrical and Physiochemical Properties of Pressboard/Oil Interface