SF₆ガス中アーク発生時の密閉容器内の圧力上昇およびエネルギー収支に及ぼす電極材質の影響

抄録

To develop an alternative test method for internal arc in SF₆-insulated power equipment, we have systematically obtained experimental data on SF₆ arc to calculate the pressure rise in power equipment. In this study, we carried out experiments on SF₆ arc in a closed container. The arcs were ignited between rod electrodes by applying a current with a peak of 10.7kA and a duration of 40ms. The rod electrodes were made of copper, iron, and aluminum. It was found that the maximum pressure rise was highest in the case of the aluminum electrode. Additionally, to determine the energy balance resulting from a SF₆ arc in the container, the energy balance was discussed on the basis of input energies and consumption energies. The input energy components are the arc energy and the energies of the decomposition reaction of SF₆, the oxidation reaction of metal vapor, and the fluoridation reaction of metal vapor. On the other hand, the consumption energy components are the energy contributing to the internal pressure rise and the energies associated with the melting of electrodes, the vaporization of electrodes, and the radiation emitted from the SF₆ arc. It was found that the input energies approximately agreed with the consumption energies. The energy of the fluoridation reaction of the metal vapor was highest in the case of the aluminum electrode, and the energy accounted for about 20% of the total input energy. Also, the radiation energy in the case of the aluminum electrode was comparable with that for the iron electrode, and the energy contributing to the internal pressure rise was highest in the case of the aluminum electrode.