Firstly, a corresponding simulation model was built on the basis of terminal structure of 220 kV high-voltage dry cable, and combined with the nonlinear conductivity equation of insulating materials, the electric field distribution and temperature distribution in the terminal with different reinforced insulating materials, ambient temperature, and applied voltage were studied. And then, the electric field distributions of the terminal with defects such as misplacement of stress cone installation, surface bulge, and bubbles in the reinforced insulation were compared and analyzed. Finally, the corner shape of stress cone and the distance between stress cone edge and reinforced insulation were optimized, the electric field distribution of the terminal after optimization was analyzed, and the optimal distance between stress cone edge and reinforced insulation was proposed. The results show that the nonlinear silicone rubber insulating material can well homogenize the electric field. The change of external ambient temperature will decrease the temperature difference between the internal core and the external umbrella skirt, and the maximum field strength in terminal increases significantly with the increase of ambient temperature. The stress cone installation dislocation makes the field strength at the three-phase junction increase sharply. The bulge on stress cone surface makes the local field strength in terminal increase sharply. When there are bubbles in reinforced insulation, the bubble size has little effect on the maximum field strength in the cable terminal. By changing the corner shape of stress cone into a circular arc shape, the field strength at the corner decreases by 75.26%. By increasing the distance between stress cone edge and reinforced insulation to 5 mm appropriately, the field strength at the stress cone corner decreases.
| 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 |