To investigate the critical conditions of high voltage cable buffer layer ablation, the types of insulation shielding damage caused by actual cable ablation were summarized in this paper. A three-dimensional asymmetric high-voltage cable model was established by finite element simulation. The ablation development process of high-voltage cables under both dry and wet conditions, as well as the mechanisms of their damage to insulation shielding, were studied separately. The difficulty of ablation under the two conditions was compared and analyzed. The results show that damage under dry condition is attributed to current-induced thermal effects caused by prolonged poor contact. When poor contact extends to 7.5 m, the surface current density on the buffer layer reaches as high as 442 A/m2, and the temperature reaches high as 200℃ within the buffer layer. Damage under wet condition arises from current-induced thermal effects caused by the high resistance products from electrochemical corrosion, and these products can penetrate areas where current and temperature are concentrated within the buffer layer. When the coverage rate of white powder reaches 97.9%, the surface current density on the buffer layer is up to 416 A/m2. Simulation results align closely with actual dissolution observed in faulty cables affected by ablation, thus validating our analysis findings presented in this paper.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |