Abstract: A first opposing surface inclination angle of a protruding first solid insulating material of a first high-voltage device is smaller than a second opposing surface inclination angle of a dented second solid insulating material of a second high-voltage device. A hollow truncated-cone flexible insulating material of which the thickness before insertion between the first high-voltage device and the second high-voltage device is the same at every part and the elasticity modulus gradually increases from a small-diameter side toward a large-diameter side, or a hollow truncated-cone flexible insulating material of which the thickness before insertion gradually increases from a small-diameter side toward a large-diameter side and the elasticity modulus is the same at every part, is compressed and sandwiched between the first solid insulating material and the second solid insulating material.

Abstract: Provided is a gas insulation device that includes a grounded metal tank in which an insulation gas is encapsulated; a conductor which is provided in the tank, on a surface of which an alumite film on which sealing treatment is performed is formed, and across which a voltage is applied; an insulating coat provided on an inner surface of the tank; and a coat that is provided on the coat and that includes an insulation material containing a non-linear resistive material.

Abstract: A first opposing surface inclination angle of a protruding first solid insulating material of a first high-voltage device is smaller than a second opposing surface inclination angle of a dented second solid insulating material of a second high-voltage device. A hollow truncated-cone flexible insulating material of which the thickness before insertion between the first high-voltage device and the second high-voltage device is the same at every part and the elasticity modulus gradually increases from a small-diameter side toward a large-diameter side, or a hollow truncated-cone flexible insulating material of which the thickness before insertion gradually increases from a small-diameter side toward a large-diameter side and the elasticity modulus is the same at every part, is compressed and sandwiched between the first solid insulating material and the second solid insulating material.

Abstract: A partial discharge determination method and apparatus, and a partial discharge determination system capable of indicating how much margin is left before dielectric breakdown, in a lighting impulse withstand voltage test, and a power device for which whether partial discharge is caused is determined by them, and a method for manufacturing a power device including the partial discharge determination method. A low-pass filter receives an acoustic signal resulting from application of an impulse voltage and acquired by an acoustic emission sensor, and removes an electromagnetic noise superimposed on the acoustic signal. A mechanical oscillation removal unit removes a mechanical oscillation component of a device under test, from the acoustic signal resulting from application of the impulse voltage which is a high voltage, based on the mechanical oscillation component acquired in advance and included in the acoustic signal resulting from application of the impulse voltage which is a low voltage.

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: A gas electrical apparatus includes: a container filled with insulating gas; a high voltage conductor arranged inside the container and applied with a prescribed voltage; and an insulating support member configured to insulate and support the high voltage conductor relative to the container. The high voltage conductor is covered by a first dielectric film. The first dielectric film includes a through hole extending from the first main surface to the second main surface. The through hole has an inner circumferential surface on which a first coating film is formed such that at least a hole diameter of the through hole is less than a diameter of an electron avalanche in a state where a gas insulated electrical apparatus is used.

Abstract: Provided is a gas insulation device that includes a grounded metal tank in which an insulation gas is encapsulated; a conductor which is provided in the tank, on a surface of which an alumite film on which sealing treatment is performed is formed, and across which a voltage is applied; an insulating coat provided on an inner surface of the tank; and a coat that is provided on the coat and that includes an insulation material containing a non-linear resistive material.

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: Gas insulated electrical equipment includes: a metal enclosure having an insulating gas introduced therein; a conductor that is accommodated inside the metal enclosure and to which voltage is applied; and an insulating and supporting member insulating and supporting the conductor relative to the metal enclosure. The conductor is circumferentially covered with a dielectric film, and furthermore, a nonlinear resistance film provided on the dielectric film and having a nonlinear volume resistivity decreasing when the nonlinear resistance film is acted on by an electric field higher than a critical value.

Abstract: A gas-insulated electrical device includes a covering film covering an inner surface of a ground tank filled with an insulation gas. The covering film is formed of an insulation dielectric covering film that becomes more positively charged than metals in a triboelectric series, and becomes positively charged upon contact with metal foreign matter. At the same time, the metal foreign matter becomes negatively charged upon contact with the covering film. In a case where the high-voltage conductor is charged to a negative polarity, a Coulomb's force acts on the metal foreign matter in contact with the covering film in a direction away from the high-voltage conductor. The metal foreign matter in the ground tank is thus suppressed from floating.

Abstract: A partial discharge detection apparatus detects a plurality of discharge events, finds a time interval between the plurality of discharge events, and determines, where the discharge events occur at a time interval shorter than a threshold time, that a partial discharge has occurred within a metal enclosure, or determines, where the discharge events occur only at a time interval longer than the threshold time, that a discharge has occurred outside the metal enclosure. The partial discharge detection apparatus can thus readily distinguish between a partial discharge that occurs within the metal enclosure of a gas-insulated switchgear and a discharge that occurs outside the metal enclosure.

Abstract: Gas insulated electrical equipment includes: a metal enclosure having an insulating gas introduced therein; a conductor that is accommodated inside the metal enclosure and to which voltage is applied; and an insulating and supporting member insulating and supporting the conductor relative to the metal enclosure. The conductor is circumferentially covered with a dielectric film, and furthermore, a nonlinear resistance film provided on the dielectric film and having a nonlinear volume resistivity decreasing when the nonlinear resistance film is acted on by an electric field higher than a critical value.

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 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 copy source inverter includes a parameter-information transmission controller that reads parameters stored in a storage area and causes a USB host controller to transmit the parameters to a copy destination inverter when the inverter is connected to the copy destination inverter. The copy destination inverter includes a parameter-information reception controller that stores the received parameters in a storage area included in the inverter when the parameters transmitted from the copy source inverter are received via a USB slave controller included in the inverter.

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: 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 method of fabricating a semiconductor optical device, a semiconductor region is formed by growing an InP lower film, a active region, an InP upper film and a capping film on a substrate sequentially. Material of the capping film is different from that of InP. Next, a mask is formed on the capping film, and the semiconductor region is etched using the mask to form a semiconductor stripe mesa, which includes an InP lower cladding layer, a active layer, an InP upper cladding layer and a capping layer. The active layer comprises aluminum-based III-V compound. A width of the top surface of the capping layer is greater than that of a width of the bottom surface of the capping layer. A width of the top surface of the InP upper cladding layer is smaller than that of the bottom surface of the InP upper cladding layer. The minimum width of the semiconductor mesa is in the InP upper cladding layer.

Abstract: A voltage-command correction unit provided between an electric-power conversion unit and a voltage-command calculation unit provides a predetermined current range including the zero level for the detected output current, and, at a first clock time when the output current enters from outside to inside of the current range, sets a zero cross timing of the output current as a clock time for switching the polarity of the correction voltage that corrects the AC voltage command calculated and output by the voltage-command calculation unit based on the first clock time and the frequency, thereby making a configuration capable of correcting the AC voltage command with the correction voltage with the same polarity as the polarity of the output current around the zero cross point of the output current.