Influence of switching regimes on dielectric strength of high current triggered vacuum switches

Switching conditions influence on dielectric strength of internal insulation of high-current triggered vacuum switches with trapezoidal-rod electrode system is investigated. Investigations were carried out for two switching regimes. In the first regime electrode erosion occurs mainly in a vapor phase where the electrode surface remains smooth after switching. In the other switching regime a drop phase of electrode erosion prevails and considerable electrode surface damage takes place. It follows from statistical processing of experimental data that the breakdown voltage distribution is described with a Weibull distribution law satisfactorily. Influence of gap and electrode material on dielectric strength of triggered vacuum switches is considered.