As a conventional technique, a configuration of a self discharge-type circuit closer is disclosed in which when the voltage between a pair of electrodes reaches a dielectric breakdown voltage in a circuit including a charged capacitor or the like, the electrodes are short-circuited to close the circuit (e.g., see Patent Document 1).
Another configuration is disclosed in which the contact elements of a pair of electrodes disposed in a vacuum vessel are brought into contact with each other to bring the electrodes into a conduction state (e.g., see Patent Document 2).
Further, as a circuit closer using a vacuum interrupter as with the aforementioned configuration, a configuration of a pulse-type circuit closer is disclosed in which: a pair of main electrodes is oppositely disposed in a vacuum vessel; a high voltage is applied to a trigger electrode provided in proximity to one or both of the main electrodes, to cause a micro-discharge between the trigger electrode and the electrode(s); and the plasma generated by the micro-discharge is injected into the main electrode(s) to break down the insulation between the main electrodes and to generate an arc, thus bringing the main electrodes into a conduction state (e.g., see Patent Document 3).
In addition, vacuum gap breakdown characteristics in the case of using oxygen-free copper as the electrode material are disclosed (Non-Patent Document 1, cited as FIG. 6 in the accompanying drawings of the present application). Dielectric breakdown voltages in the case of using different electrode materials are also disclosed (Non-Patent Document 2, cited as FIG. 7 in the accompanying drawings of the present application).