Abstract: A gas-insulated switchgear includes a grounded tank filled with insulation gas, a center conductor which is disposed in the grounded tank and to which a voltage is applied, an insulating support member which insulates and supports the center conductor, and a nonlinear resistive part disposed at least on a vertically lower side inner surface of the grounded tank and formed by an insulation material containing a nonlinear resistive material. If an electric field applied to the nonlinear resistive part is higher than an electric field value in a vicinity of a contact point between the nonlinear resistive part and a metallic foreign substance mixed in the grounded tank during an operation, a resistivity of the nonlinear resistive part at the center conductor side is lower than a resistivity at which a discharge delay time is equal to an electric field relaxation time constant.

Abstract: Each of a plurality of electrostatic shields includes an insulator portion and a conductor portion. The conductor portion includes a flat portion formed in an annular shape and a pair of protruding portions. The insulator portion is provided with a first housing portion housing the flat portion and a pair of second housing portions each housing a corresponding one of the pair of protruding portions. Each of the pair of protruding portions includes: a protruding end portion located along an inner surface of a corresponding one of the pair of second housing portions, and a center portion located adjacent to the protruding end portion. In each of the pair of protruding portions, the protruding end portion and the center portion are electrically connected to each other and are equal in electric potential to each other.

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: A water treatment device generates a bubble in water to be treated inside a treatment tank, and treats the water to be treated through use of radicals that are generated by bubble electric discharge caused via the bubble. The water treatment device includes main electrodes for forming a main discharge area between a first main electrode and a second main electrode, auxiliary electrodes for forming a preliminary discharge area between a first auxiliary electrode and a second auxiliary electrode, and a bubble generator generating a bubble in water to be treated through use of an externally supplied gas. When a bubble generated by the bubble generator passes through the preliminary discharge area, discharge is caused via the bubble, and, when the bubble in an excited state subsequently passes through the main discharge area, the bubble causes discharge again to generate radicals.

Abstract: A lead wire for a stationary induction apparatus includes a conductor, a covering insulating layer provided on an outer periphery of the conductor, and an insulating sheet provided on the covering insulating layer. The insulating sheet includes base paper having a prescribed width, and insulating spacers disposed to protrude from the base paper at prescribed spacings in a longitudinal direction of the base paper. The insulating sheet is spirally wound continuously from a straight portion to a curved portion such that the insulating spacers come into contact with the covering insulating layer.

Abstract: A gas insulated switchgear includes: a center conductor that is arranged to extend horizontally in a tank; a cylindrical member that is arranged in the tank to surround a center conductor, and formed by curving a metal plate-like member into a cylindrical shape and then joining circumferentially opposed both ends of the plate-like member by welding to form a welding portion, the welding portion being located on a lower side of the cylindrical member; and a current transformer for instruments, through which the cylindrical member is inserted, the current transformer being supported by the cylindrical member, and being arranged to surround the center conductor. The welding portion includes a metal spacer sandwiched between the circumferentially opposed both ends of the plate-like member, and the spacer and the ends are welded to each other.

Abstract: In a stationary induction apparatus, an inter-partial-coil insulating plate and a plurality of inter-partial-coil spacer insulators form a refrigerant flow path in conjunction with each other. A space having an inter-partial-coil insulation dimension for withstanding an abnormal voltage is formed between a pair of partial coils. The inter-partial-coil insulating plate and the inter-partial-coil spacer insulators support both the pair of partial coils at an insulated state so as to maintain the inter-partial-coil insulation dimension. The insulators are arranged so as to be overlapped with each other in the direction in which mutually adjacent partial coils are opposed to each other.

Abstract: A foreign matters trap in which a metallic corrugated plate is arranged in a ground tank so that a line connecting portions of the corrugated plate having the same height is made parallel to a central axis of the ground tank, a metallic round rod is mounted to an corrugated end of the corrugated plate, the corrugated plate and the metallic round rod are connected electrically to each other, and a surface of the corrugated plate is covered by an insulating material. The foreign matters trap is capable of surely trapping metallic foreign matters in a gas insulated electric apparatus and suppressing concentration of an electric field to become excellent in voltage endurance and which can be readily mounted in a ground tank.

Abstract: When electric discharging occurs inside a gas insulated apparatus in which sulfur hexafluoride is filled, hydrogen-fluoride gas is generated, which abrades a part formed of glass fiber reinforced plastics included in the apparatus. Previously, resin for preventing the abrasion has been coated on the surface of the part; however, a problem has occurred that the coating film peels off. Organic fiber woven cloth woven using organic fiber such as aramid fiber or the like having hydrogen fluoride resistance and mechanical toughness is wrapped around the surface of glass fiber reinforced plastics, and thermosetting resin is wettably impregnated into weave patterns of the organic fiber woven cloth and then heat cured; thereby, an abrasion-preventing protection layer that does not peel off is formed.

Abstract: In a stationary induction apparatus, an inter-partial-coil insulating plate and a plurality of inter-partial-coil spacer insulators form a refrigerant flow path in conjunction with each other. A space having an inter-partial-coil insulation dimension for withstanding an abnormal voltage is formed between a pair of partial coils. The inter-partial-coil insulating plate and the inter-partial-coil spacer insulators support both the pair of partial coils at an insulated state so as to maintain the inter-partial-coil insulation dimension. The insulators are arranged so as to be overlapped with each other in the direction in which mutually adjacent partial coils are opposed to each other.

Abstract: In a stationary induction apparatus, an inter-partial-coil insulating plate and a plurality of inter-partial-coil spacer insulators form a refrigerant flow path in conjunction with each other. A space having an inter-partial-coil insulation dimension for withstanding an abnormal voltage is formed between a pair of partial coils. The inter-partial-coil insulating plate and the inter-partial-coil spacer insulators support both the pair of partial coils at an insulated state so as to maintain the inter-partial-coil insulation dimension. The insulators are arranged so as to be overlapped with each other in the direction in which mutually adjacent partial coils are opposed to each other.

Abstract: A gas-insulated switchgear apparatus includes a center conductor 2, a current transformer 4 surrounding the center conductor 2, an electric field shield 5, and a metallic vessel 1. The electric field shield 5 is located between the center conductor 2 and the current transformer 4 and surrounds the center conductor 2. The current transformer 4 and the electric field shield 5 constitute a tubular part that outputs a signal representing an electric physical quantity. The metallic vessel 1 is filled with an insulating gas 19. The tubular part has an opening 6 formed therein. In a posture in which the center axis of the tubular part about which the tubular part surrounds the center conductor 2 is substantially horizontal, the opening 6 is located in a surface of the tubular part, which surface is included in a lower portion of the tubular part and faces the center conductor 2.

Abstract: A fluid-insulated electrical apparatus includes a grounded tank which is an airtight metal vessel filled with an insulating fluid. A conductor to which a high voltage is applied is disposed in the grounded tank. A metal plate that is press-processed to have an inclined portion and a groove between adjacent head top portions is fixed to and electrically connected to an inner wall of the grounded tank.

Abstract: When electric discharging occurs inside a gas insulated apparatus in which sulfur hexafluoride is filled, hydrogen-fluoride gas is generated, which abrades a part formed of glass fiber reinforced plastics included in the apparatus. Previously, resin for preventing the abrasion has been coated on the surface of the part; however, a problem has occurred that the coating film peels off. Organic fiber woven cloth woven using organic fiber such as aramid fiber or the like having hydrogen fluoride resistance and mechanical toughness is wrapped around the surface of glass fiber reinforced plastics, and thermosetting resin is wettably impregnated into weave patterns of the organic fiber woven cloth and then heat cured; thereby, an abrasion-preventing protection layer that does not peel off is formed.

Abstract: A gas insulated switchgear includes: a center conductor that is arranged to extend horizontally in a tank; a cylindrical member that is arranged in the tank to surround a center conductor, and formed by curving a metal plate-like member into a cylindrical shape and then joining circumferentially opposed both ends of the plate-like member by welding to form a welding portion, the welding portion being located on a lower side of the cylindrical member; and a current transformer for instruments, through which the cylindrical member is inserted, the current transformer being supported by the cylindrical member, and being arranged to surround the center conductor. The welding portion includes a metal spacer sandwiched between the circumferentially opposed both ends of the plate-like member, and the spacer and the ends are welded to each other.

Abstract: A gas-insulated switchgear includes an electric conductor that is housed in a vessel that is sealed and filled with insulating gas, a current transformer that is housed in the vessel, which includes a coil wound around the electric conductor, an electric-field relaxing shield that is arranged in the vessel at a radially inward position relative to an inner side of the coil, and a dielectric insulating member that is arranged on an end portion of the electric-field relaxing shield.

Abstract: A foreign matters trap in which a metallic corrugated plate is arranged in a ground tank so that a line connecting portions of the corrugated plate having the same height is made parallel to a central axis of the ground tank, a metallic round rod is mounted to an corrugated end of the corrugated plate, the corrugated plate and the metallic round rod are connected electrically to each other, and a surface of the corrugated plate is covered by an insulating material. The foreign matters trap is capable of surely trapping metallic foreign matters in a gas insulated electric apparatus and suppressing concentration of an electric field to become excellent in voltage endurance and which can be readily mounted in a ground tank.

Abstract: A gas-insulated switchgear includes an electric conductor that is housed in a vessel that is sealed and filled with insulating gas, a current transformer that is housed in the vessel, which includes a coil wound around the electric conductor, an electric-field relaxing shield that is arranged in the vessel at a radially inward position relative to an inner side of the coil, and a dielectric insulating member that is arranged on an end portion of the electric-field relaxing shield.

Abstract: A fluid-insulated electrical apparatus includes a grounded tank which is an airtight metal vessel filled with an insulating fluid. A conductor to which a high voltage is applied is disposed in the grounded tank. A metal plate that is press-processed to have an inclined portion and a groove between adjacent head top portions is fixed to and electrically connected to an inner wall of the grounded tank.

Abstract: To provide a structure capable of securing satisfactory induction coupling efficiency and high reliability in manufacturing an induction coupling apparatus used in power line carrier communication, the induction coupling apparatus having a magnetic core formed from a first core element part and a second core element part so that a gap would be formed between the core element parts, includes: a core parallel moving mechanism for carrying out relative and parallel movement of the first core element part and the second core element part in a direction that the length of the gap varies; and a predetermined gap length regulating member for limiting parallel movement in a direction that the first core element part and the second core element part approach each other to regulate the gap length to the predetermined gap length in the case that the core parallel moving mechanism is used for the parallel movement.