Abstract: A non-linear resistance film including an insulating material and a non-linear resistance material is provided on an inner surface of a grounded tank. The non-linear resistance film is formed to contain a larger amount of the non-linear resistance material on a side of a central conductor than on a side of the grounded tank. Accordingly, a gas insulated switchgear that can suppress partial discharge around metallic foreign matters and also can suppress inflow of charges from the grounded tank to the metallic foreign matters can be provided.

Abstract: To provide a gas-insulated switchgear including a metal tank that is grounded and has insulating gas filled therein, a central conductor that is extended in the tank and to which an alternating voltage is applied, an insulative coating film that is coated on an inner surface of the tank, and a coating film that is overcoated on the coating film and is formed by coating a coating material containing an insulative coating material component and a non-linear resistance material. Due to this configuration, behavior of metallic foreign matter can be suppressed in a wide range from a region having a small electric field to a region having a large electric field.

Abstract: To provide an electric current switching apparatus having a fixed-side electrode unit and a movable-side electrode unit that are arranged to align central axes thereof with each other and to face each other, in which a movable contact provided in the movable-side electrode unit reciprocates on the central axis to contact or separate from a fixed-side contact provided in the fixed-side electrode unit, thereby switching electric current flowing through these electrode units, the electric current switching apparatus including a plurality of permanent magnets that are provided in at least one of the fixed-side electrode unit and the movable-side electrode unit, that have bodies arranged on the central axis to align magnetizing directions thereof with the central axis, and that are arranged to cause same poles of adjacent ones of the permanent magnets to face each other as if butting with each other.

Abstract: A gas insulated switchgear is configured including phase-A, phase-B, and phase-C breaker units. For example, the phase-A breaker unit includes breakers connected in series in a horizontal first direction, disconnectors annexed on the breaker, disconnectors annexed on a breaker, and disconnectors annexed on a breaker. The disconnector is connected to a main bus that extends in the first direction, and the disconnector is connected to a main bus that extends in the first direction. Each of the disconnectors on the breakers is arranged while a longitudinal direction thereof is set to a second direction orthogonal to the first direction so that a switching direction of the disconnector is equal to the second direction. Thereby, the length of the main buses can be shortened, and an interphase distance and a breaker-to-breaker distance can be reduced.

Abstract: To provide an electric current switching apparatus having a fixed-side electrode unit and a movable-side electrode unit that are arranged to align central axes thereof with each other and to face each other, in which a movable contact provided in the movable-side electrode unit reciprocates on the central axis to contact or separate from a fixed-side contact provided in the fixed-side electrode unit, thereby switching electric current flowing through these electrode units, the electric current switching apparatus including a plurality of permanent magnets that are provided in at least one of the fixed-side electrode unit and the movable-side electrode unit, that have bodies arranged on the central axis to align magnetizing directions thereof with the central axis, and that are arranged to cause same poles of adjacent ones of the permanent magnets to face each other as if butting with each other.

Abstract: A gas insulated switchgear is configured including phase-A, phase-B, and phase-C breaker units. For example, the phase-A breaker unit includes breakers connected in series in a horizontal first direction, disconnectors annexed on the breaker, disconnectors annexed on a breaker, and disconnectors annexed on a breaker. The disconnector is connected to a main bus that extends in the first direction, and the disconnector is connected to a main bus that extends in the first direction. Each of the disconnectors on the breakers is arranged while a longitudinal direction thereof is set to a second direction orthogonal to the first direction so that a switching direction of the disconnector is equal to the second direction. Thereby, the length of the main buses can be shortened, and an interphase distance and a breaker-to-breaker distance can be reduced.

Abstract: A valley section is provided between a high-voltage arc contact and a high-voltage main contact. Because of the presence of the valley section, resistance between contacts is reduced while a moving arc contact makes contact with the high-voltage arc contact and then slides up to making contact with the high-voltage main contact.

Abstract: A contact device includes a first conductor and a second conductor disposed with the first conductor on a common axis and having a fitting hole into which the first conductor can be inserted. At least one of the conductors is axially moved to fit the conductors together so that a current is allowed to flow between the conductors through contacts. The contact device further includes: a conductive coil spring that is disposed circumferentially on an outer circumferential surface of the first conductor and is contactable with an inner circumferential surface of the fitting hole; and a conductive coil spring that is disposed circumferentially on the inner circumferential surface of the fitting hole and is contactable with the outer circumferential surface of the first conductor.

Abstract: A valley section is provided between a high-voltage arc contact and a high-voltage main contact. Because of the presence of the valley section, resistance between contacts is reduced while a moving arc contact makes contact with the high-voltage arc contact and then slides up to making contact with the high-voltage main contact.