Study of the ablation mechanism of high-voltage XLPE cables based on cross-interconnection grounding

Purpose This paper aims to establish a calculation model of the circulating current and loss of high-voltage cross-linked polyethylene (XLPE) cables under the cross-interconnection grounding method, and analyzing the physical mechanism of cable ablation caused by ground faults. Design/methodology/approach In view of the degree of influence of grounding defects on cable ablation, a model for calculating the ground loop current and loss of metal sheaths with unequal cross-interconnection segment lengths, unbalanced three-phase load currents, short-circuiting of inner and outer coaxial cable cores in transposition and incomplete transposition of three phases was established. The simulation experiment of wrinkled aluminum sheath ablation was carried out. Findings The differing lengths of the three cross-connected sections and the imbalance of the three-phase load current have a clear impact on the metal sheath circulation. The short circuit of the inner and outer core of land cable transposition coaxial cable and the incomplete three-phase transposition of metal sheath cross-interconnection exert a profound influence on the circulation of metal sheath. This situation will result in a considerable increase in three-phase circulation and metal sheath loss in the land cable metal sheath. In accordance with the stipulated test conditions, the requisite current is essential for the generation of white products. Originality/value The physical mechanism of the occurrence of the metal sheath ablation phenomenon is investigated from the point of view of the grounding method of high-voltage cables.