On the basis of the statistics of bird damage accidents and drainage line faults in Ningxia, the causes of drainage line faults caused by bird dropping were analyzed. The metal conductor was used to simulate bird dropping. Under the condition of power frequency, the flashover characteristics of insulated drainage lines with different structural parameters were studied. Combined with simulation analysis, the influence of insulation thickness, conductor diameter, end shape and other parameters on the flashover characteristics of insulated drainage lines was obtained. The results show that compared with the diameter of conductor, the thickness of insulation layer has big effect on the flashover characteristics of the insulation drainage line, and within a certain range, the greater the thickness of insulation layer, the greater the flashover voltage. The flashover voltage along the insulation drainage line is not always positively correlated with the increase of surface distance. Within a certain range, the flashover voltage increases with the increase of surface distance d and then tends to stable and close to a peak value. The installation of terminal head can increase the creepage distance along the surface of insulation drainage line, effectively improve the flashover voltage of the insulation drainage line, and effectively hinder the development of surface arc, which has a significant improvement on the surface flashover of insulation drainage line.
| 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 |