Research on the Correlation between the Moisture Content and Insulation Performance of XLPE Cables

Cross-linked polyethylene (XLPE) cables are widely used in urban distribution networks, but the inside structure of the cables tends to be damp after being mechanically damaged in the underground pipe corridors, resulting in deterioration of insulation performance and possible further accidents, which is not conducive to the safety and stability of the energy system. In this paper, the long-term damp process of the XLPE cables is simulated by manufacturing cable samples with different defects and placing them in a constant humidity environment. Then moisture content of the insulation layers and the insulation performance of these cables are tested to obtain the relationship between the insulation parameters and the damp extent. According to this relationship, the water content of the insulation layer in a XLPE cable can be evaluated through the detection of insulation characteristics, so as to measuring the dampness degree of the cable. This research can provide a reference for formulating the disposal methods of moist XLPE cables, and is beneficial to the operation and maintenance of the power distribution of the energy system.