Evaluation of mechanical and chemical chacteristics of 6.6 kV AC XLPE cable according to thermal aging

As the number of AC XLPE cables operated for more than 30 years increases, interest in evaluating the electrical integrity of insulating materials is increasing. Therefore, it is necessary to study long-term reliability in order to determine the replacement time of the aging AC XLPE cable. However, unlike high-voltage lines, it is difficult to manage the history of distribution lines, so the characteristic evaluation of AC XLPE cables linked with historical operating data is insufficient. In this paper, mechanical stress and chemical stress were evaluated by performing accelerated thermal aging on specimens of new 6.6 kV AC XLPE cable and old 6.6 kV AC XLPE cable. Although the mechanical and chemical characteristics of the new 6.6 kV AC XLPE specimen decreased as thermal aging progressed, there were some areas where the chemical increased due to crystallinity. The mechanical and chemical characteristics of the old 6.6 kV AC XLPE specimen decreased as thermal aging progressed. Mechanical and chemical characteristics according to thermal aging is considered to be helpful for the long-term reliability study of 6.6 kV AC XLPE cables.