Analysis of influencing factors on buffer layer discharge for high‐voltage XLPE cable

In the high-voltage (HV) cross-linked polyethylene (XLPE) cable, buffer layer has function of electrical connection and water-blocking. However, after water invades cables, discharge defect may occur, which can lead to breakdown accident cable line. It does serious harm safe stable operation power system. At present, not been sufficiently investigated in existing research. This paper establishes a voltage distribution calculation model for analyzing defect. The mechanism how presence air gap white marks (the corrosion products) between aluminium sheath influencing inside is involved this model. Based on simulation software, convenient method solving proposed. Using model, internal results under different forms are obtained. factors affecting analyzed. validity proved by test with controllable defects. show that risk be quantitatively assessed mark feature.