Title :
Mechanisms for degradation of TR-XLPE impulse strength during service aging
Author :
Boggs, Steven A.
Author_Institution :
Electr. Insulation Res. Center, Connecticut Univ., Storrs, CT, USA
fDate :
4/1/2002 12:00:00 AM
Abstract :
While the retained AC strength of TR-XLPE distribution cable appears to be quite good at about 80% of the AC strength of degassed, as-manufactured cable, the impulse strength appears to drop linearly over time and has been reported to drop by as much as 50% during the first two years of normal service aging before leveling off. In this paper, we discuss the mechanisms by which the impulse strength can degrade to a greater degree than the AC strength. Three frequency-dependent mechanisms, which include electrothermal, electromechanical, and electrical, have been identified
Keywords :
XLPE insulation; ageing; electric strength; power cable insulation; power distribution lines; trees (electrical); AC strength; EPR; TR-XLPE impulse strength degradation; distribution cable; frequency-dependent mechanisms; impulse breakdown strength; lightning impulse induced electrical phenomena; lightning impulse-induced electro-thermal-mechanical phenomena; lightning impulse-induced mechanical phenomena; normal service aging; service aging; tree retardant XLPE; Aging; Degradation; Dielectrics; Electric breakdown; Frequency; Lightning; Optical polarization; Power cables; Trees - insulation; Water heating;
Journal_Title :
Power Delivery, IEEE Transactions on
