Research on the Mechanism of High Voltage Cable Buffer Layer Ablation Fault

In recent years, power accidents of high voltage XLPE cable caused by buffer layer ablation failure have become common. How to reduce the possibility of ablation failure effectively and deal with a series of results that endanger the stable operation of the power system has become an urgent problem in the power industry. In this paper, the distributed equivalent electric network model and equivalent circuit of high voltage cable are constructed. The load capacity of the high-voltage cable under three different operating conditions, such as normal operation, a few white spots and ablative failure, is calculated. The electric field intensity distribution under three different operating conditions is simulated by multi-physics field model, and the ablation failure mechanism of buffer layer of high voltage cable is summarized. It can be seen from the analysis of the experimental results that with the increasing running time of the cable, partial discharge will occur, causing irreversible damage to the outer shielding layer and the main insulation layer. With the continuous accumulation of insulation damage, high-voltage XLPE cable breakdown will eventually occur, seriously damaging the cable structure and endangering the stable operation of the power system.