SF6 gas insulated switchgear plays an important role
in electric power networks all over the world due to its merits as
compared to traditional air insulated switchgear. According to a
numerous studies, it appears very difficult that any pure gas can
bring a solution to the issue of desirable insulation ability and low
environmental impact, so the mixtures composed of a strongly
electronegative gases with high dielectric strength such as SF6
and ordinary gases (N2, CO2, or Air) are used to reduce the gas
price and liquefaction temperature. From this point of view,
various types of gas mixtures such as(5%SF6+5%CO2+90%Air),
(5%SF6+40%CO2+55%Air),(5%SF6+80%CO2+15%Air),(5%SF6
+5%N2+90%Air),(5%SF6+40%N2+55%Air) and (5%SF6+80%
N2+15%Air) are used inside compressed gas devices to give a
higher dielectric strength with lower cost and lower
environmental impact. In this paper, the Finite Elements Method
(FEM) is used to evaluate the electric field distribution on and
around multi-contaminating filamentary wire particles. The
effect of two contaminating particles which one of them is rested
at ground plate and other is hovering inside the gap on the
electric field values are studied. The effect of three contaminating
particles which are rested at ground plate on the electric field
values are also studied. The effect of gas pressure, SF6 gas
concentration in mixture, gap spacing and height between
particles on the breakdown voltage calculations are also studied.