Diagnosis of field-aged extruded cable material using the thermally stimulated currents (TSC) method

This paper is an update of preliminary results presented elsewhere. TSC measurements were performed on samples taken from three field-aged cables which had failed after 6 to 14 years in service and one unaged cable. For the sake of comparison, the four 28-kV distribution cables were chosen for their similar manufacturing characteristics. In order to isolate the effect of electrical aging, two lengths of 63-kV cables from the same extrusion were studied: one unaged and one electrically aged in laboratory conditions without the presence of water.