Comparison for Accelerated Degradation of New and Old 6.6 kV AC XLPE Cables

XLPE (Cross-linked Polyethylene) cable has excellent chemical resistance, heat resistance and electrical characteristics, playing a pivotal role in transmission and distribution systems. In the case of distribution cables, research is needed to determine when to replace old low-voltage cables due to lack of data on operation history. In the case of cables, insulator performance degradation occurs due to temperature, so a study to evaluate long-term reliability by performing an accelerated deterioration test through thermal deterioration is necessary. The lifetime of the distribution cable was analyzed by applying the Arrhenius model, and a new XLPE cable with no operating history and an old XLPE cable with about 10 years of aging were compared. The insulation of the cable was made into specimens and accelerated deterioration at four different temperatures. The specimens of each cable were thermally degraded and the tensile strength, crystallinity and dielectric strength were analyzed. The degradation of the old specimens was found to be earlier than the new ones, and the degradation ended more rapidly. Therefore, the predicted lifetimes of the new and old specimens by the Arrhenius model were found to differ by 10 to 20 years, Therefore, if a study was conducted on a variety of cables that had been in service for longer periods of time and it can be used as a method of evaluating the life of distribution cables.