Abstract: Aiming at the ablation of the buffer layer of high-voltage cross-linked polyethylene (XLPE) cables, the influence of white powder produced by the moisture in the buffer layer on the ablation condition of the radial current concentration of the buffer layer of the cables is explored, and the degree of distortion of the electric field at the defects of the buffer layer of the cables in this condition are investigated. Using mult-physical field simulation software, a three-dimensional electro-thermal field simulation of the cableis is conducted to analyze the impact of the white powder on the internal electro-thermal field distribution of the cable. The results show that buffer layer is affected by water ingress and moisture, and the chemical reaction between water molecules and buffer layer and aluminum sheath couses the ablation of buffer layer of the cableis. At the same time, it intensifies the degree of distortion of the electric field near the defects of the buffer layer of the cable under the condition of radial current concentration ablation, which easily leads to partial discharge and subsequently triggers ablation.

Key words: highvoltage XLPE cable, buffer layer ablation, radial current concentration, white powder, electro-thermal field simulation