Charge accumulation on conical spacer in compressed SF6 gas at DC stress

Surface charging phenomena on spacers have been investigated by several researchers
^(1–5)
as collected charges may work to impair the flashover properties at the time of polarity reversal. Some charging mechanisms have been proposed, assuming gas phase
^(2,3)
epoxy bulk
⁽⁴⁾
or surface
⁽¹⁾
conduction in interpreting the charge accumulation. The authors have studied surface charging phenomena using a model cylindrical spacer placed between parallel electrodes with fine finish surface in compressed SF
6
gas and have indicated the possibility that surface charging is caused by electrical conduction on the surface of spacer.