In this paper, a multi-physics finite element model of actual 10 kV T-type cable terminal joint was established. The electric field and temperature field distribution characteristics of the T-type cable terminal joint with air gap defect at insulation interface were studied, and the change laws of electric field and temperature field amplitudes were analyzed, then the characteristic quantities reflecting the air gap defect of T-type cable terminal joints effectively and the monitored position were proposed. The results show that different degrees of air gap defects in T-type cable terminal joints have a certain impact on the electric field distribution characteristics at the interface, but the electric field and temperature field amplitudes at other typical positions do not change significantly. The air gap defect position would near breakdown under air gap damping condition, at this time, the increase of electric field amplitude on flange base and upper surface of box can reach 20%, and the temperature rise can reach 15℃. In actual engineering, the potential critical hazard of partial breakdown discharge in T-type cable terminal joint can be reflected by monitoring the increase of electric field amplitude and temperature rise of the flange base and the upper surface of box.
| 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 |