Study on Thermal Aging Test of 500kV Three-core XLPE Insulated Submarine Cable

Because of its compact structure, 500kV three-core XLPE insulated submarine cables usually heat more seriously than single-core cables of the same section, so the heat resistance of XLPE insulation and outer sheath materials is higher. In this paper, according to the standards GB/T22078.1-2008 and IEC 62067-2006, mechanical performance tests of XLPE and outer sheath of 500kV three-core XLPE insulated submarine cable prefabricated by manufacturers are carried out. thermal extension tests, and high-temperature pressure tests. The results show that the crystallinity and wafer thickness of the trial-made cable sample increase slightly at 100 °C, indicating that the proportion of antioxidants and crosslinking agents added is reasonable. At the same time, in the above experiments, the performance of XLPE sample, outer sheath sample, and cable segment sample is higher than the standard value, meeting the requirements of long-term operation.