Rejuvenation of retired power cables by heat treatment

A possible rejuvenation method of a power cable insulated with cross-linked polyethylene (XLPE) is presented. Samples with the shape of a film with a thickness of about 0.4 mm was peeled from two retired 110 kV cables and their spare cable. First, the peeled samples were annealed at 85, 90, 95 and 100 °C. Then, the differential scanning calorimetric spectrum, DC current, dielectric spectrum, indenter modulus, and dielectric breakdown were measured for these samples. As a result, we found the possibility that the XLPE insulation in the retired cables can be rejuvenated by giving a thermal treatment at a proper temperature, which is around 95 °C for the present cables.