Basic consideration on electrical and nonelectrical surface stress factors influencing the insulating capability of a dielectric surface

Summary form only given, as follows. This paper gives an overview on different stress factors and relevant aging of the surface of solid insulation applied in different types of electrical power apparatus. Depending on the kind of insulation system, different stress factors are dominating and responsible for the degradation of the surface of the solid insulating material. The amount of permissible electrical stress on the surface of an insulating solid depends on the type of the surrounding gas medium and its pressure. Such gases are atmospheric air under outdoor or indoor conditions or SF₆ under low or high pressure. The paper explains the different mechanisms and stages of surface insulation aging at different applications in the electrical power apparatus field