The effects of doping micro-SiO2 on the electrical tree resistance, thermal stability, thermal conductivity, and trap characteristics of epoxy resin under repetitive frequency bipolar square wave voltage were investigated. The results show that the electrical tree breakdown time of epoxy resin is prolonged by doping micro-SiO2, and the prolong effect is the most obvious at 10 kHz, the electrical tree breakdown time is prolonged from 6 min to 44 min. Doping micro-SiO2 can also increase the thermal conductivity of the epoxy resin and reduce the degradation of epoxy molecular chain at high temperature. The micro-SiO2 filler can introduce more deep level traps, hinder the development of electrical tree channels, extend and even block the development path of electrical tree, which decreases the damage degree of molecular chain. Therefore, doping micro-SiO2 can effectively improve the electrical tree resistance of epoxy resin under repetitive frequency bipolar square wave voltage.
| 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 |