Abstract
Researches in the area of gas insulated systems (GIS) reliability are still attracting a considerable attention from the electric utilities and the scientific community in many countries. Solid insulating spacers in GIS represent the weakest points in these systems, and several troubles and systems' outages have been reported all over the world due to their failure. So it is essential to determine the electric field distribution along their surfaces and hence evaluate the degree of their reliability. This paper discusses the electric stress distribution at the solid-gas interface with spacer's defects and contaminating spherical conducting particles on the surface. The effects of the defects size, type and its location and the particles size and its location on the electric stress distribution at solid-gas interface are presented and discussed.