Two kinds of nano-fillers nano-tiania (TiO2) and muti-wall carbon nanotubes (MWCNTS) were selected. Sixteen different epoxy nanocomposite dielectrics were prepared by adding two kinds of nanofiller alone or simultaneously to the epoxy resin. The influence of nanoparticles on the surface flashover characteristics of epoxy nanocomposite dielectrics was explored through the volume resistivity test, surface potential decay and vacuum DC surface flashover experiment. The results show that the surface flashover voltage of epoxy nano-composite is related to the mass fraction of filler, and an appropriate amount of filler can enhance the flashover voltage effectively. Comparing with adding TiO2 (improving 14.49%) and MWCNTS alone (improving 23.11%), adding TiO2 and MWCNT simultaneously can further improve the surface flashover voltage up to 44.99 kV (improving 36.06%). The surface trap characteristics of the material are calculated by the surface potential decay curve. By analyzing the relationship between deep trap and surface flashover voltage, it is found that the flashover voltage is linearly correlated with the deep trap energy level, and the deeper the trap energy, the higher the flashover voltage. The depth of surface deep trap energy is improved by adding two kinds of nanoparticle into epoxy composites, thus the electron emission and charge transport processes are suppressed, and the surface flashover voltage increases.
| 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 |