Summary
Investigations have shown that crosslinked polyethylene (XLPE) cable joints are vulnerable to moisture intrusion, which wets the composite interface, triggers discharge, and eventually causes insulation breakdown accidents. However, the mechanism of moisture-induced insulation failure at the composite interface remains unclear, limiting effective diagnosis of joint moisture conditions. This paper investigates the effect of moisture intrusion on the discharge failure process of cable joints under operating conditions. An accelerated moistureaging platform was established, and partial discharge (PD) measurements were performed on
Read more Read lessAC 10 kV power cable joints. The results show that normal cable joints exhibit no significant
PD in the early and middle stages of moisture ingress, whereas the maximum discharge amplitude increases sharply in the later stage. Finite-element simulation indicates that when moisture approaches the conductor shield along the interface, early interfacial insulation discharge is initiated, consistent with the PD results. Post-mortem examination reveals early insulation degradation, characterized by non-conductive regions and dendritic carbonization, which ultimately develops into complete interfacial insulation failure. Based on these results, four PD stages in moisture-affected cable joints are identified, providing a theoretical basis for
PD monitoring of moisture-affected cable accessories.
Additional informations
| Publication type | Session Materials |
|---|---|
| Reference | D1_12523_2026 |
| Publication year | |
| Publisher | CIGRE |
| Country | China, People's Republic of |
| Study committees | |
| File size | 1,014 KB |
| Price for non member | 30 € |
| Price for member | 30 € |
Authors
RAO Congxiao - Sichuan University; ZHU Guangya - Sichuan University; LIU Zhaogui - Sichuan University; PAN Songkun - Sichuan University
Keywords
Partial discharges, Power Cables, PD detection, Moisture Intrusion, Cable Aging
