This paper presents the breakdown voltage
characteristics of a non-uniform electric field affected by the
insertion of solid dielectric barrier under air atmosphere. The
investigations have been done experimentally and simulated in
order to study the surface breakdown phenomenon of solid
dielectric barrier. According to the experiments, the results are
divided into two parts. The first part is the pressure and the
polarity effects on breakdown voltage. The results show the
breakdown voltage increase when air pressure are increase and
the intersection between the positive and negative DC breakdown
curves at the pressure of 1.5 bars, which is supposed to be critical
pressure. At the pressure lower than 1.5 bars, the negative DC
breakdown voltage is lower than the positive case. In the other
hand, the negative DC breakdown voltage is higher than the
positive case at the pressure higher than 1.5 bars. The second
part is the simulation results of electric field distribution with
solid dielectric barrier, which is numerically analysed by Finite
Element Method (FEM). It can be described that in case of the
thicker solid barrier, the electric field stress at the contact point
is lower than the one with thinner barrier. That means the higher
applied voltage will be needed to increase the ionization process.
Therefore for the thicker solid barrier, the higher voltage must
be applied to raise the electric field strength at the contact point
to reach the breakdown condition.