Abstract: A vacuum valve includes a structure having: a container in which a fixed-side end plate and a movable-side end plate are fixed to both ends of an insulation cylinder; and an arc shield at an intermediate portion of the insulation cylinder. The vacuum valve includes: a voltage nonlinear resistance layer containing particles having a voltage nonlinear resistance characteristic at at least either one of an outer creepage surface or an inner creepage surface of the insulation cylinder. A filling rate of the particles in the voltage nonlinear resistance layer has a distribution along a film thickness direction, and a filling rate of the particles in an outermost layer is not greater than half of an average filling rate of the particles in an entirety of the voltage nonlinear resistance layer.

Abstract: A vacuum interrupter according to the present disclosure is configured such that a linear resistive layer and a nonlinear resistive layer are disposed so as to cover at least a part of a periphery of an insulation container, and a magnitude relationship of each resistivity is R1>R3>R2, where a resistivity of the nonlinear resistive layer less than an operating electric field is R1, a resistivity less than or equal to an impedance when a lightning impulse is applied is R2, and a resistivity of the linear resistive layer is R3.

Abstract: Provided is a busbar connecting device that can achieve good workability and high reliability at the same time. The busbar connecting device includes: a connection portion in which a busbar conductor and a current conductor of a bushing are connected; an insulation busbar connector covering the connection portion; a work hole communicating with the connection portion from an outside of the insulation busbar connector; and an insulating plug inserted into the work hole and sealing the insulation busbar connector, wherein a surface pressure between an inner circumferential surface of the work hole and an outer circumferential surface of the insulating plug is greater at a deep part of the work hole than at a shallow part of the work hole.

Abstract: The voltage measuring device includes: a light source; a polarizer polarizing light emitted from the light source; a grounded conductor provided apart from a high-voltage conductor; a crystal end face electrode being out of contact with the grounded conductor and the high-voltage conductor; a Pockels cell transmitting light from the polarizer; an analyzer transmitting light reflected by the Pockels cell; a photodetector detecting light emitted from the analyzer; an intra-crystal electric field measurement unit converting voltage output by the photodetector into intra-crystal electric field; a bias electrode being out of contact with the crystal end face electrode; a bias supply; a bias supply control unit controlling the bias supply to keep internal electric field of the Pockels cell at zero; and a measurement voltage calculation unit obtaining voltage of the high-voltage conductor based on results output by the intra-crystal electric field measurement unit and the bias supply control unit.

Abstract: The voltage measuring device includes: a light source; a polarizer polarizing light emitted from the light source; a grounded conductor provided apart from a high-voltage conductor; a crystal end face electrode being out of contact with the grounded conductor and the high-voltage conductor; a Pockels cell transmitting light from the polarizer; an analyzer transmitting light reflected by the Pockels cell; a photodetector detecting light emitted from the analyzer; an intra-crystal electric field measurement unit converting voltage output by the photodetector into intra-crystal electric field; a bias electrode being out of contact with the crystal end face electrode; a bias supply; a bias supply control unit controlling the bias supply to keep internal electric field of the Pockels cell at zero; and a measurement voltage calculation unit obtaining voltage of the high-voltage conductor based on results output by the intra-crystal electric field measurement unit and the bias supply control unit.

Abstract: Provided is a busbar connecting device that can achieve good workability and high reliability at the same time. The busbar connecting device includes: a connection portion in which a busbar conductor and a current conductor of a bushing are connected; an insulation busbar connector covering the connection portion; a work hole communicating with the connection portion from an outside of the insulation busbar connector; and an insulating plug inserted into the work hole and sealing the insulation busbar connector, wherein a surface pressure between an inner circumferential surface of the work hole and an outer circumferential surface of the insulating plug is greater at a deep part of the work hole than at a shallow part of the work hole.

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 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: 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 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 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.