Abstract:
Electrical inductive apparatus of the type which includes an insulating structure comprising liquid dielectric means in series with solid insulating means. The solid insulating means is formed of a first organic resin and a filler which includes a second organic resin. The first organic resin is selected to provide the required chemical resistance and mechanical properties and the second organic resin is selected to have a dielectric constant which is lower than the first organic resin, to provide solid insulating means having a composite dielectric constant which more closely matches that of the liquid dielectric means than that of the first organic resin alone.
Abstract:
A circuit interrupter including a dielectric particle trapping structure interposed between two conductors of a generally concentric arrangement which forms part of the circuit interrupter and to which a high voltage may be applied. The particle trap is particularly adapted for use with a fluid insulating system, more specifically a gaseous insulating medium such as sulfur hexafluoride. The particle trap may be disposed in the vicinity of a critical section of a high voltage conductor, where the presence of extraneous particles of dielectric or metallic material, which are suspended within the fluid may trigger high voltage breakdown if not removed. The particle trap may also be disposed proximate to an inner electrode barrier. Since the particle trap may be a dielectric material which has either corrugations or holes in it, zero or near zero electric fields are created near the holes or depressions. The particle trap allows gravity or the attraction between oppositely charged bodies to actuate charged particles to move into the zero electric field regions and onto the low voltage conductor in the circuit interrupter where the particles discharge any charge thereon. Subsequently, the electric fields in these regions are too low to allow migration of particles to the oppositely charged high voltage electrode.