Title :
The effect of gas impregnation on the time to electrical tree inception in XLPE
Author :
Bamji, S.S. ; Bulinski, A.T. ; Chen, Y. ; Densley, R.J. ; Matsuki, M. ; Iwata, Z.
Author_Institution :
Nat. Res. Council of Canada, Ottawa, Ont., Canada
Abstract :
Long-term aging tests were performed on semiconductor protrusions embedded in cross-linked polyethylene (XLPE) cables impregnated with different gases. During aging, electroluminescence emitted at the protrusion was monitored continuously until tree initiation. The results showed that oxygen in the free volume of the polymer plays an important role in the deterioration of XLPE insulation subjected to high electrical stress. Decreasing the concentration of oxygen by degassing or impregnating with N2 or SF6 increased the time to electrical treeing. While the results for N2- and SF6 -impregnated XLPE were comparable, degassed XLPE had the longest time to tree inception. It is shown that ultraviolet light emitted during electroluminescence photodegrades the polymer and can account for the differences in the times to electrical tree inception in XLPE impregnated with different gases
Keywords :
ageing; cable insulation; electric breakdown of solids; electroluminescence; insulation testing; luminescence of organic solids; organic insulating materials; polymers; N2; SF6; XLPE cable; XLPE insulation; cross-linked polyethylene; degassing; electrical stress; electrical treeing; electroluminescence; gas impregnation effect; long term ageing test; polymer; semiconductor protrusions; ultraviolet light; Aging; Cables; Electroluminescence; Gases; Monitoring; Performance evaluation; Polyethylene; Polymers; Semiconductor device testing; Trees - insulation;
Conference_Titel :
Electrical Insulation, Conference Record of the 1992 IEEE International Symposium on
Conference_Location :
Baltimore, MD
Print_ISBN :
0-7803-0649-X
DOI :
10.1109/ELINSL.1992.247054
