HV dielectric strength of shielding electrodes in vacuum circuit-breakers

The subject of this paper is the HV dielectric strength of shielding and field-grading electrodes in vacuum circuit-breakers. It describes the effects exerted by various geometrical parameters, the surface area and the material of the shielding on the breakdown behavior of shielding. The experiments were performed with a shielding electrodes model and were carried out under lightning impulse voltage. The dielectric results are discussed by means of field simulations.