121 results about "Isolated ground" patented technology

The invention relates to the technical field of power line protection, and discloses a direct-current ice melting device and a control method thereof.According to the direct-current ice melting device, an alternating-current bus of an original alternating-current ice melting module is connected into the direct-current ice melting module through an isolation grounding switch, and the control relation between the alternating-current ice melting module and the direct-current ice melting module is optimized; the alternating current ice melting module and the direct current ice melting module are controlled in a coordinated mode through the control module, on the premise that reliable and effective control is guaranteed, control hierarchy arrangement is reduced, a control link is made to be simple and efficient, control time delay is reduced, protection action time when a system breaks down is shortened, free and automatic switching of the two ice melting modules can be achieved, and the system reliability is improved. And the ice melting efficiency is improved.

The utility model discloses a gas insulated switchgear (GIS) multichannel modularized inlet and outlet wire switch interval structure, which belongs to the technical field of high-voltage switches and comprises a bottom frame, a circuit breaker, a current transformer and a three-way special-shaped steering unit, the circuit breaker and the current transformer are horizontally connected, and one sides, far away from each other, of the circuit breaker and the current transformer are connected with a three-position isolation grounding switch. The upper part of the three-position isolation grounding switch is connected with the three-way special-shaped steering unit. The left and right sides of the three-way special-shaped steering unit are connected with the cable connection terminal unit. The upper portion of the three-way upward unit is connected with the three-way special-shaped steering unit, and the left side and the right side of the three-way special-shaped steering unit are connected with the cable connection terminal unit. Through the multi-channel incoming and outgoing line modular design, multi-channel free and flexible switching can be realized, multiple use conditions are ensured, the rated and redundant through-current capability of the high-voltage switch is flexibly and effectively exerted, and the multi-group low-current combined on-off condition is satisfied. The whole structure is simple and compact, the occupied space is small, and the installation and maintenance workload is small.

The invention discloses a 220kV high-voltage combined electric appliance structure and a deconstruction method. An existing high-voltage composite apparatus is large in size and difficult to maintain. The combined electric appliance interval comprises a mutual inductor, an isolation grounding switch, a three-way bus, a wire inlet and outlet sleeve, a split bus, a double-fracture isolation switch and a movable circuit breaker. The main bus is formed by connecting buses at different intervals, the main bus is connected with the isolation grounding switch through the split bus, the isolation grounding switch is connected with the double-break isolation switch through the split bus, the double-break isolation switch is connected with the mobile circuit breaker through the split bus, the current transformer is connected with the three-way bus through the split bus, and the three-way bus is connected with the three-way bus through the split bus. The isolation grounding switch is connected with the wire inlet and outlet sleeve through a split bus. The disassembly range is reduced, other functional units do not need to be disassembled, traditional, low-efficiency and complex transfer modes such as rolling bars and cranes are replaced by the moving function, and the maintenance efficiency is remarkably improved.

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 discloses a five-defense mechanical interlocking structure used in an upper isolating switch cabinet, including a reset base, an interlocking plate, a fixed bracket, a fixing screw, a limit block, a circuit breaker indication interlocking limit block, a circuit breaker indication rotating shaft, an isolating connecting rod, a grounding connecting rod, an isolating welding baffle, an isolating fixed rotating shaft, a grounding welding baffle, a grounding fixed rotating shaft and an isolating grounding indication interlocking plate. The isolating grounding indication interlocking plate is conducive to its own appearance design, the isolating welding baffle and the grounding welding baffle are linked with the circuit breaker indication interlocking limit block through the isolating connecting rod and the grounding connecting rod, the limit block and the limit dial block in the circuit breaker indication interlocking limit block are bent to form an interlocking relationship with the interlocking plate, the interlocking plate is interlocked with the lower door of the cable room through the reset base, and the four-block combination realizes the five-defense interlocking function. The invention has reliable performance and simple assembly, fully meets the five-defense interlocking performance requirements, greatly improves the safety of the switch cabinet equipment, and is more conducive to the safety of the power system and operators.

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 the technical field of medium-voltage distribution network looped network switch equipment, in particular to an environment-friendly gas insulation PT cabinet, which is characterized in that a mechanism chamber is positioned at the front part of a sealed gas box, an instrument chamber is positioned at the top of the mechanism chamber, a pressure relief chamber is positioned below the sealed gas box, and a cable chamber is positioned below the mechanism chamber; a three-position switch device is arranged in the sealed gas tank and is filled with nitrogen or dry air, and the three-position switch device comprises an isolating switch and a grounding switch; the mechanism chamber is internally provided with an isolation / grounding operation mechanism, and the isolation / grounding operation mechanism is used for triggering the opening and closing of the isolation switch. The ring network switch cabinet has the beneficial effects that the pollution of the ring network switch cabinet to the environment is reduced, and the problem that the inter-phase and relative-to-ground insulation capability of conductive parts is insufficient is solved.

The utility model relates to the technical field of electrical cabinets, in particular to a mechanical electrical interlocking structure of a high-voltage fixed cabinet, which comprises a JSXGN upper isolation and upper grounding interlocking mechanism, and the JSXGN upper isolation and upper grounding interlocking mechanism is used for completing upper isolation, upper grounding and opening a corresponding high-voltage chamber door. The wire inlet end live display and the wire outlet end live display are used for realizing electrical interlocking of auxiliary elements; and the upper-stage circuit breaker is connected with the wire inlet end of the circuit and is used for controlling the on-off of the whole circuit. According to the mechanical and electrical interlocking structure of the high-voltage fixed cabinet provided by the utility model, under the condition that an energy storage element is arranged at an isolation wire outlet end, the operation and interlocking of an isolation switch and a grounding switch are separated, the problem of non-on-load opening and closing isolation is solved, the electrified closing of the grounding switch is avoided, and a powerful guarantee is provided for the safety of high-voltage power distribution and maintenance.

The invention relates to a segmented flat plate structure high-field asymmetric waveform ion migration tube and application, the segmented flat plate structure high-field asymmetric waveform ion migration tube comprises an insulating cylinder with a rectangular cross section, the lower wall surface of the cylinder is an insulating lower plate, and the upper wall surface of the cylinder is an insulating upper plate; an ionization source is arranged between the insulating lower plate and the insulating upper plate and close to a left port of the cylinder, and an isolation ground electrode pair and an ion receiving electrode pair are arranged between the insulating lower plate and the insulating upper plate and close to a right port; between the ionization source and the isolated ground electrode pair, two or more pairs of opposite sectional electrode pairs are arranged on the upper surface of the lower insulating plate and the lower surface of the upper insulating plate, and the working air pressure range is 10 Pascals to 1 atmospheric pressure; the moving speed of ions in the X-axis direction can be reduced, and the separation capacity is improved.

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 utility model discloses a power conversion and detection circuit and a household appliance. The power conversion and detection circuit comprises a signal processing branch, a voltage conversion branch, a feedback branch, a zero-cross detection branch and a controller. And the signal processing branch is used for rectifying and filtering. The voltage conversion branch comprises a power management chip and a transformer, and the voltage conversion branch controls the primary coil to be charged or discharged through the power management chip based on a feedback signal. And the feedback branch outputs a feedback signal. The zero-cross detection branch comprises a first optocoupler, the first optocoupler and a ground pin of the power management chip are connected to a first ground, and the first optocoupler and the secondary coil are connected to a second ground. The zero-crossing detection branch outputs a first level in response to the alternating-current power supply in the positive half cycle and outputs a second level in response to the alternating-current power supply in the negative half axis, so that the controller determines a zero-crossing point. By means of the mode, the non-isolated ground and the isolated ground formed in the power supply conversion process can be used for eliminating power loss when the alternating current power supply is in the negative half cycle.

The invention provides substation electrical equipment totally-enclosed insulation arrangement equipment, which relates to the technical field of substations, and comprises a transformer, a three-station isolation grounding combination switch, a rigid gas insulation power transmission line, a gas insulation combined electric appliance, a totally-insulated inflatable looped network switch cabinet and an integrated sleeve, two rigid gas insulated transmission lines are led out from the transformer, the three-station isolation grounding combination switch is arranged between the transformer and the rigid gas insulated transmission lines, the all-insulation inflatable looped network switch cabinet is arranged at the tail ends of the rigid gas insulated transmission lines, and the gas insulated composite apparatus is connected in series with the middle sections of the rigid gas insulated transmission lines. And the integrated sleeve is arranged on the rigid gas insulated transmission line. According to the invention, the insulation performance and the safety of the electrical equipment are improved, the service life of the electrical equipment is prolonged, the equipment layout is optimized, the construction cost is reduced, a rapid switching function is provided, and the compatibility and the use convenience of the equipment are enhanced.

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 present invention discloses an integrated interlocking mechanism of an inflatable cabinet, which is mainly composed of a valve card plate, a first interlocking crank arm, a closing brake assembly, a rotating assembly, a transmission assembly and a reset assembly. By arranging the first interlocking crank arm on the main shaft of the circuit breaker operating mechanism, connecting the valve card plate to the operating valve of the direct-acting three-position mechanism, and arranging the closing brake assembly, the rotating assembly, the transmission assembly and the reset assembly between the first interlocking crank arm and the valve card plate, the function of being unable to open the operating valve of the three-position mechanism for manual operation when the circuit breaker of the inflatable cabinet is in the closed state is realized, and the function of being unable to close the circuit breaker during the manual operation of the three-position mechanism in the circuit breaker opening state is also realized. Therefore, the present invention realizes the mechanical interlocking function between the three-position isolation grounding switch of the inflatable cabinet and the circuit breaker, and has the advantages of simple structure, active interlocking and safety and reliability.

The invention relates to the technical field of gas insulated switch devices, in particular to a series fracture vacuum grounding switch device and a ring main unit. A series connection fracture vacuum grounding switch device comprises a wire inlet end and a wire outlet end, a circuit breaker and a three-position isolation grounding switch are sequentially connected between the wire inlet end and the wire outlet end in series, and the three-position isolation grounding switch comprises an isolation switch static contact seat, a contact knife assembly and a grounding switch assembly. The isolating switch static contact seat is connected with the circuit breaker to form a conductive loop, the grounding switch assembly comprises a grounding contact, and the contact knife assembly is movably arranged between the isolating switch static contact seat and the grounding contact to realize conduction with the isolating switch static contact seat or the grounding contact. The grounding switch assembly further comprises an arc extinguishing breaking device which is closed after the contact knife assembly moves to the grounding contact. The arc extinguishing on-off device of the grounding switch assembly has the arc extinguishing capability, and a circuit breaker does not need to be operated during grounding operation, so that the operation link is simplified, and the misoperation possibility of operation and maintenance operators is avoided.

The present invention belongs to the technical field of isolating and grounding switches, and relates to a three-phase common-box type three-position isolating and grounding switch, comprising a housing, within which are disposed three sets of isolating and grounding devices and a three-phase linkage device; the housing comprises a main tube, on which are disposed three pairs of mutually perpendicular horizontal and vertical support tubes; each set of isolating and grounding devices comprises a vertical isolating static contact, a vertical moving contact, a horizontal isolating static contact, a horizontal moving contact, and a grounding static contact; the vertical moving contact and the horizontal moving contact are arranged vertically within a moving contact support seat, the vertical isolating static contact being disposed within an upper support tube, the support tube being disposed within a lower support tube, the horizontal isolating static contact being disposed within a rear support tube, and the grounding static contact being disposed within a front support tube; the three-phase linkage device comprising a transmission shaft and three gear transmission devices, the gear transmission devices being disposed on the transmission shaft. This solves the problems of current three-phase common-box isolating switches, such as large housings, heavy weight, and high costs, and the need for busbar power outages for on-site GIS expansion and maintenance.

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 utility model discloses a rail transit integrated grounding load switch device, which comprises a cabinet body, a contactor, a mounting rack, a contact knife switch, an isolation grounding knife switch and a control assembly, and is characterized in that the cabinet body comprises an accommodating cavity, the contactor is arranged in the accommodating cavity and can connect or disconnect a load circuit, and the mounting rack is arranged in the accommodating cavity and can connect or disconnect the load circuit; the contact disconnecting link is arranged on one side of the mounting frame and is connected with the contactor in parallel, the isolation grounding disconnecting link is arranged on the other side of the mounting frame, the contactor, the contact disconnecting link and the isolation grounding disconnecting link are connected through copper bars, and the isolation grounding disconnecting link can connect or disconnect a load circuit. The control assembly can control the opening and closing of the contactor, the contact disconnecting link and the isolation grounding disconnecting link. The technical scheme of the utility model facilitates the collection and transmission of the whole signal, facilitates the improvement of the installation convenience, saves the occupied area, and saves the workload of construction, on-site wiring and debugging.

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.