A grounding switch for grounding a high voltage cable in underground switchgear. The switch includes a solid insulation housing and a fixed electrode extending into one end of the housing and being encapsulated in the solid insulation housing. The switch also includes a ground electrode positioned at an opposite end of the housing from the fixed electrode, an air gap formed in the solid insulation housing between the fixed electrode and the ground electrode, and a movable electrode slidable positionable within the air gap to electrically connect and disconnect the fixed electrode to and from the ground electrode. An annular shielding electrode having a ridge is electrically coupled to the fixed electrode proximate the air gap, and shapes an electric field generated by the fixed electrode to be mostly confined within the solid insulation housing.

The present invention provides an electrical insulating material for high voltage equipment which suppresses precipitation of additive materials, while achieving electrical and mechanical properties equal to or higher than those of the conventional ones. An electrical insulating material for high voltage equipment according to an embodiment of the present invention includes: a resin (3); and additive materials (1, 2) and fine particles (4) dispersed in the resin (3), wherein the fine particles (4) have the same main skeleton as the additive materials (1, 2), and have an average particle diameter of 1-200 nm, and some of atoms forming the main skeleton are bonded to an organic group and an inorganic group, and are arranged around the additive materials (1, 2).

A switching apparatus and a switching system are provided. The switching apparatus comprises an insulating housing comprising a housing wall, a disconnector disposed inside the insulating housing and at least partially surrounded by the housing wall, an insulated branch busbar disposed outside the insulating housing, such that part of the housing wall is disposed between the disconnector and the insulated branch busbar, an insulated connection element passing through the housing wall connecting the second end of the disconnector to the insulated branch busbar, and an insulated phase busbar connected to the branch busbar. The switching system comprises a plurality of switching apparatuses.

A switching apparatus and a switching system are provided. The switching apparatus comprises an insulating housing comprising a housing wall, a disconnector disposed inside the insulating housing and at least partially surrounded by the housing wall, an insulated branch busbar disposed outside the insulating housing, such that part of the housing wall is disposed between the disconnector and the insulated branch busbar, an insulated connection element passing through the housing wall connecting the second end of the disconnector to the insulated branch busbar, and an insulated phase busbar connected to the branch busbar. The switching system comprises a plurality of switching apparatuses.

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.

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.

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.

The disclosure relates to a gas insulated electric apparatus, which includes an enclosure, an electric high voltage appliance arranged inside the enclosure and a permeation barrier arranged within the enclosure and circumferentially surrounding the electric high voltage appliance, whereby the enclosure contains an insulation gas including at least 70% by volume of CO.sub.2 and including an elevated and pre-determined operating gas pressure level, and the permeation barrier includes a permeation layer surrounded on at least one side by a flow promoter layer and/or a surface activation and/or primer layer.

A submersible electrical enclosure is for a switchgear assembly. The switchgear assembly includes a number of electrical switching apparatus. The submersible electrical enclosure includes: a plurality of sides defining an interior, the interior receiving each of the electrical switching apparatus, each side including: a conductive polymeric layer facing away from the interior, and an insulative polymeric layer molded to the conductive polymeric layer. The insulative polymeric layer faces the interior and substantially overlays the conductive polymeric layer.

A submersible electrical enclosure is for a switchgear assembly. The switchgear assembly includes a number of electrical switching apparatus. The submersible electrical enclosure includes: a plurality of sides defining an interior, the interior receiving each of the electrical switching apparatus, each side including: a conductive polymeric layer facing away from the interior, and an insulative polymeric layer molded to the conductive polymeric layer. The insulative polymeric layer faces the interior and substantially overlays the conductive polymeric layer.