Analysis of the Inhibition of Different Dendritic Defects in Cables by Silicone Repair fluid

Abstract

Through preliminary experimental research and field application, it is found that, as an excellent repair agent for cable water tree defects, the silicone water tree repair liquid has a good water tree repair effect to support its wider engineering application prospects. In view of the diversity of dendritic defects in cables, this paper explores the characteristics of the effects of the injection of silicone repair fluid on the generation and growth of different types of dendritic defects and provides a certain theory for the extended research of multi-defect repair methods and the improvement of repair efficiency, which has high research value. In this paper, an experimental platform for aging and repair of dendritic defects of cross-linked polyethylene (XLPE) cables is established. Using block XLPE and pin-plate electrodes to build an uneven electric field inside the cable. Change the frequency and amplitude of the applied electric field, moisture content, and other external conditions to simulate the generation and development of three types of defects: water tree, electric tree, and electrical tree-water tree coordinated development in cable insulation. In addition, the injection of the repair liquid was performed in the form of a control experiment. By comparing the micro-morphology, partial discharge, and Growth characteristics of electric tree of each defect sample before and after the repair fluid injection, the inhibition characteristics of the silicone repair fluid for different dendritic defects in cables were explored. The results showed that: After the repair fluid was injected, the maximum local discharge and the number of discharges of the three types of defective samples decreased, and the breakdown voltage per unit length of the samples increased. Various insulation characteristics confirm the inhibitory effect of water tree repair fluid on the growth of various defects. Among them, water tree samples had the best inhibitory effect, followed by wet electric trees. Finally, the inhibition mechanism of silicone repair solution to different defects is analyzed and summarized, which provides certain theoretical guidance for improving the repair solution to have the function of simultaneously repairing different defects in the future.