An Experience of Ageing on XLPE Insulation

A case study of ageing on XLPE conductor insulation of 20kV primary distribution feeder is presented in this paper. The insulation degradation mainly occurred around conductor tie where the conductor is attached to the post insulator. A section of distribution feeder with defects on the conductor insulation has been examined for this study. Potential losses due to presence of discharges have been investigated by measuring the difference current at locations of the affected conductor. Temperature measurements of the insulation surface have also been carried out. Provisional maintenance procedures were introduced to eliminate the discharges. Measurements of current and surface temperature were repeated nine months after completion of the maintenance work. Results indicated that the discharges have been completely disappeared.