Surface flashover characteristic of epoxy resin composite material in SF

6

/CF

4

mixture were studied throughexperimental method

and the influence of several key parameters were analyzed

such as gas pressure

SF

6

mixratio and voltage polarity. During experiment

the needle-plate electrodes structure to simulate the extremely unevenelectric field. The electrode spacing is 5 mm

and the testing pressure is 0.1

0

.4 MPa. Resul

ts show that

when themix ratio of SF

6

in the mixed gas is 40%

the flashover voltage of epoxy resin insulator can reach over 60% of theflashover voltage in SF

6

with the same pressure. The synergistic effects in needle-plate electrodes system are of largedistinguish difference under different polarity

which is much weaker under negative polarity than that undernegative polarity. The flashover voltage shows significant polarity effect

but this effect reverses when the gaspressure increases. This reversal is because the distortions of positive and negative particles to the electric field areentirely different under different polarity voltages. Comprehensive environmental requirements and surface flashovercharacteristics

the results provide a potential SF

6

alternative for GIS equipment.