Title :
Final breakdown mechanism
Author :
Pélissou, S. ; Noirhomme, B. ; Parpal, J.-L.
Author_Institution :
Hydro-Quebec, Varennes, Que., Canada
Abstract :
Preliminary results on the final breakdown mechanism of XLPE (cross-linked polyethylene) insulated field-aged cables are presented. The main goal is to determine the conditions that lead to the growth of electrical trees from water trees. Samples peeled off from two 28 kV and well-characterized (density, impurity and water content, field-water-tree density, oxidation) cables are considered. Aging conditions were 10 kV/mm, 60 Hz, 0.05 M NaCl solution, and 22-23°C. The results indicate that after 8000 h of aging the lab-water-tree length reaches 65-70% of the sample thickness and is not much affected by the presence of field water trees. The influence of the physico-chemical properties and AC breakdown strength is also reported
Keywords :
ageing; cable insulation; electric breakdown of solids; organic insulating materials; polymers; power cables; 22 to 23 degC; 28 kV; 8000 h; AC breakdown strength; XLPE; ageing conditions; cross-linked polyethylene; density; electrical trees; field-water-tree density; final breakdown mechanism; impurity content; insulated field-aged cables; oxidation; physico-chemical properties; water content; Aging; Cable insulation; Degradation; Dielectrics and electrical insulation; Electric breakdown; Impurities; Laboratories; Oxidation; Testing; Trees - insulation;
Conference_Titel :
Properties and Applications of Dielectric Materials, 1991., Proceedings of the 3rd International Conference on
Conference_Location :
Tokyo
Print_ISBN :
0-87942-568-7
DOI :
10.1109/ICPADM.1991.172287
