Abstract: A compact and economical gas-insulated switchgear is provided. The gas-insulated switchgear includes: a grounding metal housing 1 filled with insulating gas, and in which the disconnector part 2 having a moving side electrode part 2a and a stationary side electrode part 2b is accommodated; and composite insulating shields 17a, 17b integrally formed into one metal-dielectric member in which surface of a high electric field part located in the vicinity of ends of openings is coated with a dielectric so as to cover the moving side and stationary side electrode parts 2a and 2b with the dielectric. To form the composite insulating shields 17a, 17b, a metal shield of less than 0.6 in non-uniform constant before coating with the dielectric is coated with dielectrics 18a, 18b having a thickness of not more than approximately 30% of an inter-electrode distance from a facing electric-field relaxation shield.

Abstract: A compact and economical gas-insulated switchgear is provided. The gas-insulated switchgear includes: a grounding metal housing 1 filled with insulating gas, and in which the disconnector part 2 having a moving side electrode part 2a and a stationary side electrode part 2b is accommodated; and composite insulating shields 17a, 17b integrally formed into one metal-dielectric member in which surface of a high electric field part located in the vicinity of ends of openings is coated with a dielectric so as to cover the moving side and stationary side electrode parts 2a and 2b with the dielectric. To form the composite insulating shields 17a, 17b, a metal shield of less than 0.6 in non-uniform constant before coating with the dielectric is coated with dielectrics 18a, 18b having a thickness of not more than approximately 30% of an interelectrode distance from a facing electric-field relaxation shield.

Abstract: Disclosed is a transformer for a gas insulated electrical apparatus which requires no grounding field and which provides high accuracy with a simple structure. A transformer includes a capacitor type voltage divider having a floating electrode at a position opposed to a high-voltage conductor through an insulation sealing terminal mounted to a flange of a branch pipe provided on an inner surface of the annular grounding container; an ohm resistor for voltage division which has an impedance that is sufficiently smaller than the impedance between the floating electrode and the annular grounding container; and a converting portion which converts the detection voltage of the high-voltage conductor to a voltage value that allows processing on the secondary side.

Abstract: In a three-phase current transformer, a plate adaptor includes first to third coil insertion slots and is a magnetic shield. First to third Rogowskii coils are arranged in the first to third coil insertion slots. The metal adaptor is fixed with a phase-to-phase magnetic shield and an outer peripheral magnetic shield. An end magnetic shield is fixed to an end portion of the phase-to-phase magnetic shield.

Abstract: A failure determining apparatus for a gas-insulated electrical appliance where the appliance is a cylindrical metal container with a charged conductor, insulating gas, and a plurality of insulating spaces inside for supporting the conductor and partitioning the container. The failure determining apparatus has a high-speed developing sensor which detects a high-speed phenomenon caused by a failure within the gas sections; a first failure determining circuit which determines the presence of a failure from an output of the high-speed developing sensor; a low-speed developing sensor which detects a low-speed phenomenon caused by a failure within the gas sections; a second failure determining circuit which determines the presence of a failure from an output of the low-speed developing sensor; and an arithmetic control circuit which identifies a gas section of the metal container in which a failure occurs from an output of the first and second failure determining circuits.

Abstract: Disclosed is a transformer for a gas insulated electrical apparatus which requires no grounding field and which provides high accuracy with a simple structure.

Abstract: In a three-phase package type current transformer, first to third coil insertion slots are formed in a plate-like metal adaptor that serves as a magnetic shield. First to third Rogowskii coils are arranged in the first to third coil insertion slots. The metal adaptor is fixed with a phase-to-phase magnetic shield and an outer peripheral magnetic shield. An end magnetic shield is fixed to an end portion of the phase-to-phase magnetic shield.

Abstract: A gas insulated switching device including a series of pressure containers 1 and 4 mutually connected, in which a conductor 2 is positioned in an inside center, and an insulating and arc-extinguishing gas is filled in a space around the conductor 2, and a current transformer fabricated by Rogowskii coils for detecting a current passing through the conductor 2, the current transformer is attached to flanges of the pressure containers 1 and 4 via a metallic adaptor 5, wherein the current transformer is accommodated in a groove formed toward an inside of the metallic adaptor 5 and uses the metallic adaptor 5 to obtain an earth potential, whereby the gas insulated switching device having the current transformer with high accuracy can be miniaturized.

Abstract: A failure determining apparatus of a gas-insulated electrical appliance determining a failure, having a cylindrical metal container, a charged conductor housed in the metal container filled with an insulating gas, and a plurality of insulating spaces insulation-supporting the charged conductor from the metal container and partitioning the interior of the metal container into gas sections, comprising a high-speed developing sensor which detects a high-speed phenomenon caused by a failure such as a ground-fault or a short-circuit within the gas sections; a first failure determining circuit which determines the presence of a failure from an output of the high-speed developing sensor; a low-speed developing sensor which detects a low-speed phenomenon caused by a failure such as a ground-fault or a short-circuit within the gas sections; a second failure determining circuit which determines the presence of a failure from an output of the low-speed developing sensor; and an arithmetic control circuit which identifie