| Title |
Evaluation of Water Tree Propagation and Dielectric Strength in Tree-Retardant XLPE using FEM Electric Field Analysis |
| Authors |
서예슬(Ye-Seul Seo) ; 김가현(Ga-Hyun Kim) ; 최현준(Hyen-Jun Choi) ; 임장섭(Jang-Seob Lim) |
| DOI |
https://doi.org/10.5370/KIEE.2026.75.8.1893 |
| Keywords |
Tree retardant XLPE; Water tree; Finite Element Method(FEM); Dielectric breakdown strength |
| Abstract |
To secure the reliability of extra high voltage power cables, evaluating the properties of TR XLPE is essential. This study fabricated pinhole defect specimens of commercial XLPE and TR XLPE A, B to verify their water tree suppression and initial dielectric strength. FEM analysis quantified an electric field concentration of 475kV/mm at the defect tip, which coincided with the actual water tree initiation site in accelerated aging tests. The maximum water tree growth lengths were 331μm for TR XLPE A and 212μm for TR XLPE B. Weibull analysis of initial AC breakdown strength showed that the scale parameter of TR materials, 11.8kV/mm, improved by 5.4% over commercial XLPE, and the shape parameter of TR XLPE B increased by 15.4%. By correlating numerical electric field stress with physical degradation and statistical breakdown thresholds, this study provides baseline indicators that can be utilized as a standard for evaluating the secondary dielectric strength of aged cable insulation. |