Field Application of Defect Localization and Extending Life Technology for XLPE Cables in Distribution Systems

According to statistics from State Grid Corporation of China, a large number of cable lines in operation are subjected to varying degrees of moisture or water ingress. The proportion of moisture and water ingress lines exceeds 60%. Among them, more than 80% of cables are affected by moisture or moisture intrusion at cable joints, leading to breakdown. The paper summarizes the defect localization method and repair technology of cross-linked polyethylene (XLPE) cables in response to the problems of moisture and water tree aging in large-scale cables in urban power grids. Firstly, it introduces the principle and implementation scheme of precise localization technology for local defects in distribution cables based on frequency domain reflection method; Secondly, it elaborates on the use of organic silicon repair technology to extend the service life of water tree aging XLPE cables and improve insulation performance; Finally, it introduces successful field application cases of defect localization and repair technology.