66 results about "Isolated ground" patented technology

The application discloses a three-position mechanism position signal operating mechanism and an isolated grounding switch. The mechanism comprises a top plate and a bottom plate, the top plate is provided with a second position signal device, and the bottom plate is provided with a first position signal device; a transmission device is connected with a driving device at one end and connected with the first position signal device and the second position signal device at the other end; after the operating mechanism receives an operation instruction, the driving device drives the transmission device to drive the first position signal device and the second position signal device to displace respectively, and double signal confirmation is performed. The double signal confirmation mechanism effectively avoids the possible misjudgment of a single signal, improves the accuracy of the position signal, and ensures that the background control system and the protection equipment can perform logical judgment based on accurate data.

This invention belongs to the field of electromagnetic interference (EMI) suppression technology, and proposes an EMI suppression device using isolated grounding. It includes shielded modules that act as interference sources or receivers for each other, and a shielded transmission circuit for signal transmission. The shielded modules include camera mechanisms, modules that easily generate high-frequency signals, and modules that easily generate large currents. The shielded transmission circuit includes transmission cables connecting each shielded module. This device is simple, easy to implement, and easy to operate. It mainly utilizes the conductivity of metallic materials to transmit external electromagnetic interference, which is easily received by the shielded modules and the transmission circuit cables, to the ground through a conductive layer. Simultaneously, the transmitted circuit signals are also protected, thus preventing electromagnetic interference to the shielded modules and the transmission circuit cables, allowing the equipment to maintain normal operation.

The utility model relates to the technical field of gas insulated switchgear, and especially relates to a GIS with a protective device. A GIS with a protection device comprises an isolation grounding switch shell flange connecting part, a bus cylinder flange connecting part and an insulation spacer which are fixedly connected through threaded connecting pieces, a protection cover with a downward opening is fixedly assembled on the bus cylinder flange connecting part, the protection cover is used for covering the bus cylinder flange connecting part, and the isolation grounding switch shell flange connecting part, the bus cylinder flange connecting part and the insulation spacer are fixedly connected through threaded connecting pieces. The protective cover is provided with a central hole for avoiding the bus cylinder, and the central hole of the protective cover is in sealing fit with the bus cylinder. Rain and snow are prevented from entering the insulation basin through the threaded connection part of the threaded connection piece, the insulation basin is prevented from cracking due to large expansion force after water accumulated at the insulation basin is frozen in an environment with low air temperature, and the sealing reliability of the GIS equipment is ensured.

The invention provides a convenient IGBT protection device, and belongs to the field of low-voltage frequency conversion / inversion, the convenient IGBT protection device comprises an IGBT, a radiator, a first protection device and a second protection device, the first side of the IGBT is fixed through a busbar bolt and is electrically connected with a laminated busbar, the second side of the IGBT is fixed through a busbar bolt and is electrically connected with a fixed busbar, and the second side of the IGBT is electrically connected with the laminated busbar. The first side and the second side of the IGBT are fixedly connected with the radiator through grounding bolts respectively, a first protection device is installed at the position of the grounding bolt at the first side of the IGBT in a limiting mode, a second protection device is installed at the position of the grounding bolt at the second side of the IGBT in a limiting mode, and the first protection device and the second protection device can completely wrap and isolate the grounding bolts. According to the device, the creepage distance between the terminals and between the terminals and the fixing screws can be effectively increased, the insulation performance is improved, and the creepage distance between the terminals is effectively increased due to the design that the partition plates are additionally arranged between the DCP / DCN terminals. The device is convenient to install and maintain, and the maintenance and repair efficiency of the IGBT is greatly improved.

The invention discloses a gas tank device of an environment-friendly gas-filled switch cabinet, and relates to the technical field of intelligent power grid power transformation and high-voltage power transmission and distribution, the gas tank device comprises a top expansion bus gas chamber (23) formed by welding stainless steel plates, the top expansion bus gas chamber (23) is of a full-sealed structure, and environment-friendly gas with the pressure not exceeding 0.05 MPa is filled into a full-sealed gas filling device (25); a high-voltage live part is packaged in the full-sealed inflation device (25) and comprises a three-station isolating / grounding switch (13), a vacuum circuit breaker (15), a bus of a copper bar structure and a high-voltage live conductor insulating sleeve. The conductors in the air chamber equipment are subjected to electric field optimization design, silver plating and polishing, the insulation performance of a primary part can be ensured, and the reliability and the stability of the air chamber equipment are equivalent to those of sulfur hexafluoride inflation equipment.

The application relates to the technical field of electrostatic protection, and particularly discloses an isolated composite PNP tube, a high-voltage electrostatic protection structure and electronic equipment, which comprises a P-type substrate, a P-type epitaxial layer arranged on the P-type substrate, and an N-type buried layer arranged between the P-type substrate and the P-type epitaxial layer; a plurality of spaced active regions are arranged on the surface of the P-type epitaxial layer; the active regions located in the outer region are connected with metal wires and then serve as lead-out ends of an isolated ground end; the plurality of active regions located in the central region are connected with metal wires and then serve as lead-out ends of a collector of a longitudinal PNP tube, a collector of a transverse PNP tube and a base and an emitter shared by the longitudinal PNP tube and the transverse PNP tube; and the active regions located between the outer region and the central region are connected with metal wires and then serve as lead-out ends of an isolated port. The isolated composite PNP tube provided by the application has strong high-voltage electrostatic protection capability and can effectively prevent negative pulse triggering latching when being applied to the high-voltage electrostatic protection structure.

The utility model relates to a compact sleeve retraction type composite combined electric appliance for a 145kV mobile transformer. The compact sleeve retraction type composite combined electric appliance is characterized by comprising a three-phase tank type circuit breaker, a three-pole three-station isolation grounding switch, an elbow bus, a current transformer, an airtight retraction rotating device and a composite sleeve, according to the 145kV composite combined electric appliance, an airtight retraction rotating device is designed, so that the casing pipe of the product is rotated and forms are switched under the condition that gas in the product is not leaked, and the maximum insulation distance size is ensured; a transportation form and an operation form can be switched; the whole structure is designed in a non-over-limit width range, the whole width is smaller than 2.55 m, moving and carrying are convenient, and meanwhile the transportation safety is improved.

A gas insulated switch device comprises a first spacing unit and a second spacing unit, the first spacing unit and the second spacing unit respectively comprise a first accommodating shell, a second accommodating shell and a third accommodating shell which correspond to each other, and the first accommodating shell, the second accommodating shell and the third accommodating shell have at least partially identical structures; the first accommodating shell comprises a circuit breaker control mechanism, the second accommodating shell is filled with insulating gas and comprises a circuit breaker and an isolation grounding switch, and the third accommodating shell comprises a cable terminal used for being connected with a cable; the first accommodating shell is arranged above the second accommodating shell, the third accommodating shell is adjacent to the second accommodating shell and is arranged on at least one side of the second accommodating shell, and the first spacing unit is detachably connected with the second spacing unit. The design is beneficial to installation and maintenance, parts can be exchanged, universally used and reused, meanwhile, design verification and production manufacturing are facilitated, and the research and development and production cost is reduced.

The invention relates to the technical field of power equipment, and discloses an electricity testing locking system and a control method and a state prompting method thereof, which are used for still keeping the electricity testing locking of an isolation grounding device under the condition of power loss of a secondary power supply. An electricity testing locking controller in the electricity testing locking system is provided with a super capacitor which is charged when a secondary power supply works normally and responds to triggering of a power supply awakening button when the secondary power supply loses power, so that the super capacitor provides temporary electric energy for the electricity testing locking controller through an internal electrical loop; the super capacitor supplies power to the power supply module through a second normally open contact and a third normally open contact of the relay in the discharge control loop. The electricity verification locking controller is provided with a second open contact connected to the isolation grounding device switch unlocking loop. Therefore, unlocking and locking control is carried out on the isolation grounding device based on an unlocking and locking instruction output by the electricity testing and locking controller after electricity testing of the contact network.

The utility model relates to an outdoor high-voltage isolation grounding type vacuum circuit breaker, and belongs to the technical field of circuit breakers. Comprising a support, a circuit breaker body, a movable connecting structure, a first fixing structure and a second fixing structure, the movable connecting structure is installed at the bottom of the support, the circuit breaker body is installed on the support through the first fixing structure and the second fixing structure, and the first fixing structure comprises a fixing plate, a threaded column, a locking nut, a limiting rod and a first magnet. The limiting rod is a magnetic metal rod which can be adsorbed with the first magnet; the support is installed on the installation structure through the movable connection structure, the distance between the connection plates can be adjusted, the installation structure can be adapted conveniently, meanwhile, the circuit breaker body is installed on the support through the first fixing structure and the second fixing structure in an easily detachable mode, operation is simplified, and use is more convenient.

The invention provides a land flexible direct current converter station direct current field arrangement system and an operation control method, and relates to the technical field of flexible direct current transmission, and the system comprises a bridge arm reactor, an isolation grounding switch, a direct current measuring device, a direct current voltage measuring device, a direct current lightning arrester, a wall bushing and an energy consumption device which are conventionally configured in a land converter station direct current field. The devices are connected through tubular buses and flexible conductors. According to the invention, a double-spliced direct current submarine cable scheme is adopted for high-capacity offshore wind power flexible direct current transmission, on the basis of conventional direct current field configuration, by adding three isolation grounding switches, no power failure can be realized when any two direct current submarine cables are in an outgoing line fault, and the reliability of high-capacity offshore wind power flexible direct current transmission is greatly improved.

The invention discloses a 40.5 kV environment-friendly gas-insulated switchgear, which relates to the technical field of high-voltage power transmission and distribution equipment, comprises a top expansion bus chamber (6), a mechanism chamber (1), a cable chamber (3) and an anti-explosion pressure relief channel (4) which are formed by separation of partition plates, and is characterized by further comprising a fully-sealed gas-insulated compartment (5) formed by welding stainless steel plates with the thickness being greater than or equal to 3mm, the full-sealed inflatable compartment (5) is filled with dry air with rated pressure of 0.04 MPa, all 40.5 kV high-voltage live parts are packaged in the full-sealed inflatable compartment (5), the full-sealed inflatable compartment (5) comprises a vacuum circuit breaker fracture (10), a three-station isolating / grounding switch (7), a main bus (13), a branch bus (12) and a wire outlet sleeve (11), the surfaces of the main bus (13) and the branch bus (12) are polished, and the surface of the main bus (13) and the surface of the branch bus (12) are filled with dry air with rated pressure of 0.04 MPa. And a double-shielding cover (14) is additionally arranged at a stress concentration part where the double-shielding cover (14) is connected with the supporting insulator (15).

The invention relates to the technical field of electrical switch equipment, and discloses an electrical cabinet and an integrated three-position isolation grounding switch mechanism thereof. In the switch mechanism, an isolation operation assembly and a grounding operation assembly are symmetrically arranged on a frame structure, each operation assembly comprises an operation shaft, an input transmission part, an output transmission part and a middle transmission part, and a first pin is arranged on the middle transmission part. The two ends of the spring are connected with the first pins on the two sides respectively, when the operation shaft on any side rotates, the corresponding first pin moves to enable the spring to store energy, and when the first pins on the two sides and the axis of the spring are collinear and then cross a dead point, the spring releases energy to drive the corresponding output transmission piece to rotate rapidly. According to the invention, two functions of isolation and grounding are simultaneously realized in a single module through the symmetrical double-operation assembly and the over-dead-point quick energy release mechanism, and the device has the advantages of compact structure, quick and reliable action, good symmetry and perfect safety protection.

The invention relates to the technical field of switch equipment, in particular to a three-phase common box type isolation grounding switch and a GIS (Gas Insulated Switchgear). The three-phase common box type isolation grounding switch comprises a three-way shell, two opposite openings of the three-way shell are distributed in the first direction, a middle phase and a side phase which are arranged in a triangular mode are arranged between the two opposite openings, and each of the middle phase and the side phase comprises a phase conductor and an isolation static contact. A moving contact seat is further arranged on one side of the middle phase and the side phase in the second direction in the three-way shell, the second direction is perpendicular to the first direction, the moving contact seat and the first direction form a set included angle and are obliquely arranged, a direct-acting moving contact is arranged in the moving contact seat, the middle phase is located on one side, close to the moving contact, of the side phase, and the second direction is perpendicular to the first direction. The conductor of the middle phase is provided with a bending section which is recessed towards the space between the two side phases, and the part, corresponding to the corresponding moving contact seat, of the bending section in the second direction is far away from the moving contact seat by being recessed. According to the invention, the middle phase is arranged close to the moving contact seat, so that the overall size is reduced to the maximum extent.

The invention discloses a 27.5 kV middle tank type environment-friendly high-voltage alternating-current metal-enclosed switchgear, which comprises a mechanism chamber, an instrument chamber, a cable chamber and an expansion chamber, and is characterized in that the instrument chamber and a bipolar vacuum circuit breaker are responsible for controlling the on-off of a circuit in a circuit breaker tank body; the isolating switch is responsible for isolating the on-off of a circuit in the tank body and respectively realizing three states of isolation, grounding and closing, the whole body adopts an extensible mode design, the cable chamber is taken as a center, the mechanism chamber, the instrument chamber, the lower chamber and the extension chamber are respectively arranged on a left combined cabinet and a right combined cabinet, a group of combinations with different functional units is formed, and a plurality of extension mode designs are formed. The movable contact can form stable and reliable conductive connection with the high-voltage static contact, the isolation static contact and the grounding static contact, so that flexible switching among three working states of connection, isolation and grounding is efficiently realized, the stability of conductive connection is enhanced, the problems of poor contact and improper switching are reduced, and the service life of the switch is prolonged. And the working reliability and accuracy of the isolating switch are ensured.

The invention discloses an isolation grounding switch structure for a transformer substation. The isolation grounding switch structure comprises a worm, a limiting ring, an outer ring sheath, a grounding knife transmission buckle and a knife transmission buckle. The relative rotation of the outer ring sheath is linked with the worm to rotate through the adaptive connection of the ground knife transmission buckle and the ground knife tooth groove or the adaptive connection of the knife transmission buckle and the knife tooth groove, so as to drive the knife and the ground knife operation body to rotate. The position of the limiting ring in the outer ring sheath is changed through synchronous linkage of relative rotation of the outer ring sheath, and the limiting ring is linked to change the grounding knife transmission buckle to move away from the grounding knife tooth groove step by step or change the disconnecting link transmission buckle to move away from the disconnecting link tooth groove step by step, so that the grounding knife transmission buckle or the disconnecting link transmission buckle is separated from the worm. According to the isolation grounding switch structure for the transformer substation, the operation of the disconnecting link and the operation of the grounding switch can be separated, and misoperation is avoided; the structure is simple, repair and maintenance are easy, and product cost is controlled.

The invention discloses a long-line high-voltage cable metal isolation grounding joint and an installation method. The grounding joint comprises a grounding metal sleeve shell, a lead sealing structure and a multifunctional wrapping layer. The grounding metal sleeve shell comprises two grounding semicircular shells which sleeve the outer side of an exposed cable metal layer, the two grounding semicircular shells are fixedly connected through a locking structure, and one of the grounding semicircular shells is provided with a grounding leading-out terminal used for being connected with a grounding cable; the two groups of lead sealing structures respectively wrap the two end parts of the grounding semicircular shell, and the lead sealing structures are simultaneously and fixedly connected with the end parts of the grounding semicircular shell and the cable metal layers at the corresponding positions; and the multifunctional wrapping layer wraps the outer sides of the grounding semicircular shell, the lead sealing structure and the exposed cable metal layer. The invention has the advantages of good connection reliability, good sealing performance, small occupied space and the like.

The application relates to the field of switch devices, in particular to a main bus conductor, a main bus conductor assembly and an isolated grounding switch. The main bus conductor comprises a conductor section, the two ends of the conductor section are respectively provided with a first electric connection structure and a second electric connection structure, and a groove extending along the length direction of the conductor section is arranged on the conductor section. The application improves the main bus conductor in the prior art, the groove is arranged on the conductor section along the length direction of the conductor section, which is beneficial to reducing the use of materials and facilitating weight reduction; since the conductor surface mainly plays a role in current conduction when the conductor transmits alternating current, the central part of the conductor section does not contain a part with low electric conduction efficiency, which is beneficial to improving the utilization rate of the materials; in addition, the conductor surface area and the heat dissipation area are increased due to the groove, which is beneficial to timely heat dissipation of the conductor during the working process, therefore, the problems of the main bus conductor in the prior art, such as large weight, low material utilization rate and poor heat dissipation, are solved.

A device assembly is provided that is capable of selectively connecting one or more tracer wires to ground and isolating one or more tracer wires from ground. The device assembly includes a housing, an electrical switch within the housing, and one or more contact assemblies. The tracer wire(s) and the ground wire are connected to one or more contact assemblies. The electrical switch can connect the tracer wires to the ground wire and can isolate the tracer wires from the ground wire.

The application relates to a gas-enclosed switch device system, which comprises a mounting base plate, a total isolation grounding switch module mounted on the mounting base plate, an incoming line isolation grounding switch module mounted on a first connecting hole and electrically connected with the total isolation grounding switch module, and an outgoing line isolation grounding switch module mounted on a second connecting hole and electrically connected with the total isolation grounding switch module. The total isolation grounding switch module is provided with the first connecting hole and the second connecting hole which are arranged in the same direction and are spaced from top to bottom. The incoming line isolation grounding switch module has an incoming line interface which is different from the direction of the first connecting hole. The outgoing line isolation grounding switch module has an outgoing line interface which is different from the direction of the second connecting hole. Compared with a traditional longitudinal arrangement scheme, the device is miniaturized, the problem of the too large longitudinal size of an offshore wind power layout is solved, intensive and modular design is realized, and the special requirements of the offshore wind power layout on the gas-insulated switch device are met.

The utility model relates to the technical field of optical fiber sensing, and discloses an optical fiber mutual transmission measurement and control device and a rail transit cross-station locking system, which are used for improving the efficiency of network communication in rail transit cross-station locking. The optical fiber mutual transmission measurement and control device comprises a switching value input module, an optical fiber mutual transmission module, a control module and a switching value output module. The switching value input module is connected with an isolation grounding device of the station and is used for acquiring the state of a disconnecting link of the isolation grounding device; the optical fiber mutual transmission module is in communication connection with an optical fiber mutual transmission measurement and control device of an adjacent station and is used for receiving a disconnecting link state of an isolation grounding device of the adjacent station; and the control module is respectively connected with the switching value input module, the switching value output module and the optical fiber mutual transmission module.

The invention relates to the technical field of isolating switches, in particular to a three-station isolating grounding switch for a GIS (gas insulated switchgear), which comprises an isolating shell, a static contact seat and a grounding contact seat which are matched with a movable contact seat are arranged in the isolating shell, a round hole and a notch communicated with the round hole are formed in the front end of the movable contact seat, and a sliding block elastically slides in the notch; the outer wall of the contact end of the contact finger is slidably sleeved with a clamping ring, the rear end of the clamping ring is provided with a positioning rod, the end of the positioning rod elastically slides in the circular hole in a matched mode, the clamping ring makes contact with the end of the inner cavity of the static contact base before the contact finger, and when the clamping ring and the contact finger are in a closing state attached to the end of the inner cavity of the static contact base, the positioning rod extrudes the outer wall of the sliding block to abut against the inner wall of the static contact base. Through the cooperation of the clamping ring and the sliding block, the clamping ring is firstly contacted with the static contact seat in the switching-on process, mechanical friction and scraping caused by axis deviation between the contact finger and the inner wall of the static contact seat are avoided, the completeness and smoothness of the surface of the contact are protected, and the centering deviation is actively corrected through the radial extension of the sliding block.

The invention provides a double-fracture isolation grounding switch, and belongs to the field of circuit breakers. The double-fracture isolation grounding switch comprises a first moving contact, a second moving contact and a gear transmission mechanism, the gear transmission mechanism comprises a transmission shaft, a first rack, a second rack, a first gear and a second gear, the second rack comprises a rack main body and a reversing matching body, and the rack main body comprises a toothed section and a toothless section. And after the second moving contact is opened, the second gear is separated from the toothed section and corresponds to the toothless section, the second gear comprises a gear main body and a reversing shifting body located at the axial end part of the gear main body, and the reversing shifting body is used for shifting the reversing matching body to enable the toothed section to be meshed with the gear main body again. According to the double-fracture isolation grounding switch, the second moving contact can stay in situ in the grounding closing process of the first moving contact, the overall size of the double-fracture isolation grounding switch can be reduced, and the double-fracture isolation grounding switch can be used under the condition that the GIS equipment interval size is limited.

The utility model relates to a high-voltage one-to-three-phase gas insulation metal enclosed isolation grounding switch device, which comprises a sleeve branch and a switch assembly, the switch assembly comprises a shell, a straight conductor, a triangular conductor and three isolation grounding switch assemblies, the straight conductor, the triangular conductor and the three isolation grounding switch assemblies are arranged in the shell, and the shell is provided with a single-phase insulator and a three-phase insulator. One end of the straight conductor is connected with a single-phase conductor of the single-phase insulator, the other end of the straight conductor is connected with the triangular conductor, one ends of the three isolation grounding switch assemblies are respectively connected with a three-phase conductor of the three-phase insulator, and the other ends of the three isolation grounding switch assemblies are all connected with the triangular conductor; the sleeve branch comprises an outgoing line sleeve, a bent pipe branch bus and a straight pipe branch bus which are connected in sequence, and the straight pipe branch bus is connected with the single-phase insulator. The device is compact in structure and simple to operate, can realize rapid butt joint with a GIS product, does not need repeated operation during a test, is convenient to use, and greatly improves the test efficiency.

A power supply circuit includes a supply input including a positive terminal, a neutral terminal, and a negative terminal, wherein an input voltage is applied to the positive terminal and the negative terminal; a first switching converter circuit referenced to the neutral terminal and having a first converter input coupled to the positive terminal, and a first converter output to produce a first regulated output voltage referenced to an isolated ground electrically isolated from the supply input; a second switching converter circuit having a second converter input coupled to the neutral terminal and the negative bus terminal, and a second switching converter circuit referenced to the negative terminal and having a second converter input coupled to the neutral terminal, and a second converter output to produce a second regulated output voltage referenced to the isolated ground.

The invention discloses a combined shielding structure and an isolation grounding switch, and the combined shielding structure comprises a resistor outer shield and a resistor inner shield. The resistor outer shield is positioned at one end of the resistor and is used for shielding an electric field of a resistor mounting part and balancing a fracture electric field; and the resistor inner shield is mounted at one end, close to the moving contact, of the resistor outer shield, and is used for forming an arc path with the moving contact when a fault occurs, and introducing fault current into a resistor loop. By using the shielding structure in the isolation grounding switch, 'no-load no-input and on-load automatic input 'of a resistor loop is realized through a gap between a moving contact and a resistor inner shield, so that the mechanical transmission structure and fracture design of the isolation switch with the closing resistor are greatly simplified; therefore, the overall size, the manufacturing complexity and the production cost of the product are reduced.

The present invention increases an area occupied by a first circuit and a second circuit, while ensuring isolation between the first circuit and the second circuit. A ground electrode (3) is disposed on a second main surface (102) of a mounting substrate (1), and is located between the second main surface (102) of the mounting substrate (1) and an IC chip (2). The IC chip (2) has a first circuit (21), a second circuit (22), a boundary region (B1), and a ground terminal (G1). The boundary region (B1) is a region between the first circuit (21) and the second circuit (22). The ground terminal (G1) overlaps a portion of the boundary region (B1) when viewed in plan view from a thickness direction of the mounting substrate (1), and is connected to the ground electrode (3). The ground electrode (3) overlaps the boundary region (B1) between the first circuit (21) and the second circuit (22) when viewed in plan view from the thickness direction of the mounting substrate (1).

The invention discloses a valve area grounding fault processing method, device and equipment and a storage medium, belongs to the technical field of high-voltage direct current transmission, and is applied to a direct current transmission system, the direct current transmission system comprises a valve group and a converter transformer, and the converter transformer comprises a Y-bridge converter transformer and a D-bridge converter transformer. The method comprises the steps of determining that a valve group is in a differential protection action state; determining that a ground fault occurs in an area surrounded by the direct current side of the valve group and the valve side of the converter transformer; determining that a connecting line between the valve side of the converter transformer and the valve group or a common part of the Y-bridge converter transformer and the D-bridge converter transformer has a grounding fault; through the locking valve group, an inlet wire switch of the converter transformer is tripped off, and a grounding fault is isolated. The invention aims to identify the grounding fault of the valve area of the direct-current power transmission system, and for the fault which can realize fault isolation through valve group locking, the fault isolation can be realized only by locking the fault valve group.

The utility model relates to a single-pole 31.5 kv composite combined electric appliance, which comprises a 31.5 kv tank type circuit breaker, a current transformer, a 31.5 kv isolation grounding switch and a sleeve, the 31.5 kv tank type circuit breaker is installed on a cross beam, the upper end face of the 31.5 kv tank type circuit breaker is provided with two phase column interfaces which are distributed in a V shape, and the upper end of each phase column interface is sequentially provided with a current transformer, a 31.5 kv isolation grounding switch and a sleeve from bottom to top. The 31.5 kv tank-type circuit breaker is provided with a circuit breaker shell wrapping all the elements, the current transformer is provided with a transformer shell wrapping all the elements, and the 31.5 kv isolation grounding switch is provided with an isolation switch shell wrapping all the elements. And the circuit breaker shell, the mutual inductor shell and the isolating switch shell are matched and fixed through flanges. The unipolar 31.5 kv composite combined electric appliance is suitable for a traction substation power supply system, and can automatically identify fault types, protect a power supply circuit and realize intelligent control of the circuit.

The utility model discloses a miniature cable testing device for a ring main unit, which comprises a cable testing unit, the cable testing unit comprises a grounding cable testing end sleeve, a first branch bus, a second branch bus and a branch bus appearance sleeve, the grounding cable testing end sleeve is connected with a grounding contact through the first branch bus, and the branch bus appearance sleeve is connected with the grounding contact through the second branch bus. According to the utility model, the grounding cable test end sleeve is connected with the grounding contact of the existing isolation switch through the first branch bus, and the branch bus appearance sleeve is connected with the lower isolation grounding of the existing isolation switch through the second branch bus. The three phases of the grounding switch are led out through the independent grounding cable testing end sleeves of the first branch bus, the size of the cable testing device is reduced, the miniaturization requirement of the cable testing end is met, and meanwhile the size of the ring main unit with the cable testing end scheme can be further reduced according to the requirement in the installation layout remaining place.