Abstract: A gas insulated apparatus includes: a grounded metal tank in which an insulating gas is enclosed; a conductor disposed in the tank, voltage being applied to the conductor; and a non-linear resistance layer disposed on at least part of an inner surface of the tank and made from an insulating material containing a particle of a non-linear resistance material, the non-linear resistance material being conductive when voltage higher than or equal to a threshold is applied. The non-linear resistance layer has a thickness that is larger than a sum of a thickness of a conductive portion and a particle diameter of the non-linear resistance material, the conductive portion being a portion of the non-linear resistance layer that is conductive when voltage higher than or equal to the threshold is applied to a metal foreign object on the non-linear resistance layer.

Abstract: This power conversion device includes a plurality of power conversion units, a first electric field relaxation shield, a second electric field relaxation shield, and a third electric field relaxation shield. The first, the second and the third electric field relaxation shield include a first end, a second end and a third end, respectively. The first electric field relaxation shield and the second electric field relaxation shield surround the plurality of power conversion units when viewed from a direction in which the first electric field relaxation shield and the third electric field relaxation shield are overlapped each other. The third end is disposed at any position within a range from a position overlapping the first end to a position overlapping the second end when viewed from the direction in which the first electric field relaxation shield and the third electric field relaxation shield are overlapped each other.

Abstract: A gas-insulated electrical apparatus according to the present invention comprises a grounded tank, a conductor placed inside the grounded tank, and an insulation gas filling the grounded tank. The insulation gas is a mixed gas comprising a first gas mainly responsible for insulation performance and having a global warming potential less than 6500, and a second gas having a small molecular weight, a low insulation performance, and a low global warming potential, as compared to the first gas. The insulation performance of the insulation gas is lower than the insulation performance of the first gas at a same pressure.

Abstract: A gas insulated apparatus includes: a grounded metal tank in which an insulating gas is enclosed; a conductor disposed in the tank, voltage being applied to the conductor; and a non-linear resistance layer disposed on at least part of an inner surface of the tank and made from an insulating material containing a particle of a non-linear resistance material, the non-linear resistance material being conductive when voltage higher than or equal to a threshold is applied. The non-linear resistance layer has a thickness that is larger than a sum of a thickness of a conductive portion and a particle diameter of the non-linear resistance material, the conductive portion being a portion of the non-linear resistance layer that is conductive when voltage higher than or equal to the threshold is applied to a metal foreign object on the non-linear resistance layer.

Abstract: A gas-insulated electric apparatus includes: a sealed container made of metal; a high-voltage conductor, housed within the sealed container, that receives voltage; an insulating support member that insulates the high-voltage conductor from the sealed container and support the high-voltage conductor to the sealed container; and a nonlinear-resistance film covering at least a portion of an inner surface of the sealed container, the portion being on a lower side of the inner surface with respect to the high-voltage conductor. The nonlinear-resistance film is formed by particles of a nonlinear-resistance material and an insulating material, and the particles of the nonlinear-resistance material are dispersed in the insulating material. The particles of the nonlinear-resistance material are placed in the insulating material such that one or more of the particles of the nonlinear-resistance material is in constant contact with a conductive foreign object trapped inside the sealed container.

Abstract: A coating material of the present invention includes an insulating resin, and dispersion particles dispersed in the insulating resin. The dispersion particle includes a core particle containing zinc oxide as a main component and having nonlinear resistance, and a resin layer covering the surface of the core particle and having an average thickness being less than or equal to 5.0 ?m. The coating material of the present invention is a coating material for coating an inner surface of a ground tank of a gas insulated switchgear.

Abstract: A gas-insulated electrical equipment includes: a grounded tank filled with an insulating gas; a central conductor which is disposed inside the grounded tank and to which to apply a voltage; a high-resistance insulating portion which is disposed on an inner surface of the grounded tank and which is configured of an insulating material of high resistivity; a low-resistance insulating portion which is disposed on at least a partial front surface of the high-resistance insulating portion and which has a resistivity lower than that of the high-resistance insulating portion, and a non-linear resistance insulating portion which is disposed on at least a partial front surface of the low-resistance insulating portion and which is configured of a non-linear resistance material, which exhibits a non-linear resistivity relative to a change in electric field, and an insulating material of high resistivity, wherein the low-resistance insulating portion has a floating potential.

Abstract: In a connecting device of an electrical apparatus in which a first solid insulator and a second solid insulator each molded as a solid insulator on a periphery of a center conductor are connected to each other via a flexible insulator, a high voltage electrode having an outer diameter larger than those of the center conductors is disposed in the second solid insulator, and a ground electrode having an inner diameter smaller than that of an outer ground layer of the second solid insulator and larger than the outer diameter of the high voltage electrode is disposed in the first solid insulator. Electric field directions at an interface between the first solid insulator and the flexible insulator and at an interface between the second solid insulator and the flexible insulator are directions along the respective interfaces.

Abstract: A stator coil accommodated in a slot of a rotary electric machine includes a coil conductor, a main insulating layer, a low resistance corona shield layer, and a stator coil extending outside the slot is provided with a first stator coil at the end of the low resistance corona shield layer has a first nonlinear resistance layer and a second nonlinear resistance layer partially overlapping with an end of the first nonlinear resistance layer, and a lower limit value of an electric resistivity of the second nonlinear resistance layer in a predetermined electric field is larger than an upper limit value of an electric resistivity of the first nonlinear resistance layer by one order of magnitude or more.

Abstract: A gas-insulated electric apparatus includes: a sealed container made of metal; a high-voltage conductor, housed within the sealed container, that receives voltage; an insulating support member that insulates the high-voltage conductor from the sealed container and support the high-voltage conductor to the sealed container; and a nonlinear-resistance film covering at least a portion of an inner surface of the sealed container, the portion being on a lower side of the inner surface with respect to the high-voltage conductor. The nonlinear-resistance film is formed by particles of a nonlinear-resistance material and an insulating material, and the particles of the nonlinear-resistance material are dispersed in the insulating material. The particles of the nonlinear-resistance material are placed in the insulating material such that one or more of the particles of the nonlinear-resistance material is in constant contact with a conductive foreign object trapped inside the sealed container.

Abstract: A gas-insulated electrical equipment includes: a grounded tank filled with an insulating gas; a central conductor which is disposed inside the grounded tank and to which to apply a voltage; a high-resistance insulating portion which is disposed on an inner surface of the grounded tank and which is configured of an insulating material of high resistivity; a low-resistance insulating portion which is disposed on at least a partial front surface of the high-resistance insulating portion and which has a resistivity lower than that of the high-resistance insulating portion, and a non-linear resistance insulating portion which is disposed on at least a partial front surface of the low-resistance insulating portion and which is configured of a non-linear resistance material, which exhibits a non-linear resistivity relative to a change in electric field, and an insulating material of high resistivity, wherein the low-resistance insulating portion has a floating potential.

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: A coating material of the present invention includes an insulating resin, and dispersion particles dispersed in the insulating resin. The dispersion particle includes a core particle containing zinc oxide as a main component and having nonlinear resistance, and a resin layer covering the surface of the core particle and having an average thickness being less than or equal to 5.0 ?m. The coating material of the present invention is a coating material for coating an inner surface of a ground tank of a gas insulated switchgear.

Abstract: A stator coil accommodated in a slot of a rotary electric machine includes a coil conductor, a main insulating layer, a low resistance corona shield layer, and a stator coil extending outside the slot is provided with a first stator coil at the end of the low resistance corona shield layer has a first nonlinear resistance layer and a second nonlinear resistance layer partially overlapping with an end of the first nonlinear resistance layer, and a lower limit value of an electric resistivity of the second nonlinear resistance layer in a predetermined electric field is larger than an upper limit value of an electric resistivity of the first nonlinear resistance layer by one order of magnitude or more.

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: In a connecting device of an electrical apparatus in which a first solid insulator and a second solid insulator each molded as a solid insulator on a periphery of a center conductor are connected to each other via a flexible insulator, a high voltage electrode having an outer diameter larger than those of the center conductors is disposed in the second solid insulator, and a ground electrode having an inner diameter smaller than that of an outer ground layer of the second solid insulator and larger than the outer diameter of the high voltage electrode is disposed in the first solid insulator. Electric field directions at an interface between the first solid insulator and the flexible insulator and at an interface between the second solid insulator and the flexible insulator are directions along the respective interfaces.

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 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 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 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.