Probabilidad

Investigation of Dielectric Breakdown Probability Distribution for Vacuum Disconnecting switch
Tetsu Shioiri, Kosuke Sasage, Tom Kamikawaji ,Mitsutaka Homma and E.Kaneko, Senior Member, IEEEAbsmcf-Vacuum insulation system has little effect on environments. Therefore, vacuum insulation system is expected to find wider application. such as disconnecting switch and earthing switch. To investigatethe reliability of equipment of vacuum insulation, a study was carried out to clarify breakdown probability distributions in vacuum gap. Experiments were carried out to compare a uniform field gapand non-uniform field gap on the breakdown probability distributions. Further, experiments were carried out to investigate effects of no-load switching on the breakdown probability distributions forvacuum disconnecting switch. The electrode materials were oxygen-free copper and copper-chromium alloy. The test results show that the breakdown probability distribution of the vacuum gap can berepresented by a Weibull distribution using a location parameter, which show the voltage that permits a zero breakdown probability. When aiming for highly reliable vacuum disconnecting switch, an importantfactor is insulation design with the location parameter just mentioned take into account. The location parameter obtained Weibull plot depends OD electrode area. This is probably because the existenceprobability of factors as weak-points for breakdowns such as micro-protrusions and microparticles depends on the electrode area. The shape parameter obtained Weibull plot of vacuum gap was 1013, and isconstant irrespective non-uniform field factor. The breakdown probability distribution after no-load switching can he represented by Weibull distribution using P loeation parameter. The shapeparameter after no-load switching was 6-8.5, and is constant, irrespective of gap length. This indicates that the scatter of breakdown voltage was increased by no-load switching. It is supposed that the...