Gas-insulated switchgear and system

Abstract

The present invention relates to the technical field of electrical devices, and provides gas-insulated switchgear and a system; the gas-insulated switchgear comprises a cabinet body, wherein a busbar compartment, a switch compartment, and a circuit breaker compartment are provided within the cabinet body, the busbar compartment is configured for providing a busbar, the switch compartment is configured for providing a switch, and the circuit breaker compartment is configured providing a circuit breaker pole; the present invention further comprises a three-position switch, wherein the three-position switch is fixedly disposed within the cabinet body by means of a side-mounted insulator, the three-position switch is directly connected, by means of a copper bar, to the circuit breaker pole mounted in the circuit breaker compartment, and the busbar compartment, the switch compartment, and the circuit breaker compartment are sealed within the same gas compartment by means of the three-position switch. The present invention effectively resolves the technical problems in the prior art of complex gas-filled enclosure structures and high gas-filled enclosure processing costs which result from switchgear using compartment bushings to connect three-position switches and circuit breakers.

Description

A gas-insulated cabinet and system Technical Field

[0001] This invention relates to the field of electrical equipment technology, specifically to a gas-filled cabinet and system. Background Technology

[0002] Gas-insulated switchgear is a new generation of switchgear, specifically indoor AC high-voltage gas-insulated metal-enclosed switchgear. The main switch can be either a permanent magnet vacuum circuit breaker or a spring-mechanism vacuum circuit breaker. The entire cabinet combines air insulation with sulfur hexafluoride gas compartments, featuring: compact structure, easy expansion, and suitability for power distribution automation; robust cabinet structure, excellent airtightness, and each functional unit is an independent module for easy assembly; and independent pressure relief channels to maximize personal safety and equipment operation.

[0003] There are three types of main busbars for gas-insulated switchgear: top connection, side connection, and field busbar connection with vacuum filling. From a manufacturing and installation process perspective, field busbar connection is the easiest to implement, followed by top connection, with side connection having the highest requirements. From a cost perspective, field busbar connection has the lowest cost, followed by side connection, with top connection having the highest requirements. From a product quality control perspective, top connection is the best, followed by side connection, with field busbar connection having the lowest requirements.

[0004] Various gas-insulated switchgear structures are disclosed in the prior art. For example, utility model CN219739745U discloses a 40.5kV high-current gas-insulated switchgear structure, including a double-pole disconnector assembly, a cabinet, and a heat dissipation assembly. The double-pole disconnector assembly is disposed in the cabinet, and the heat dissipation assembly is disposed on the cabinet. The cabinet includes a first housing section, a second housing section, and a third housing section, with the second housing section disposed between the first and third housing sections. The double-pole disconnector assembly is disposed in the second housing section. In this solution, the internal heat dissipation section can quickly remove the temperature from the poles, ensuring that the poles are always used within a safe range. At the same time, the first, second, and third heat dissipation fin groups can accelerate the thermal radiation efficiency of the entire cabinet. The addition of four fans enhances air circulation, allowing the entire cabinet to better exchange heat with the surrounding environment, thereby achieving the standard temperature rise of the product.

[0005] The existing gas-insulated cabinets have the following shortcomings:

[0006] First, existing gas-filled switchgear uses a three-position switch for fixing. Currently, the TGP-40.5 switchgear uses a compartment bushing to connect the three-position switch and the circuit breaker, resulting in a complex gas box structure and high gas box processing costs.

[0007] Secondly, the current transformers in the existing gas-insulated switchgear are installed in the cable compartment, with the cable heads located above the current transformers. The current transformers cannot protect the cable heads, and when a fault occurs at the cable heads during the operation of the power grid system, it can easily lead to a power outage of the entire system.

[0008] Third, the current transformers in the existing gas-insulated switchgear are installed in the cable compartment, with the cable head above the current transformer. The current transformer cannot protect the cable head. When a fault occurs at the cable head during the operation of the power grid system, the insulation between the cable head and the inner cone overlap is damaged, forming an arc, causing combustion or even an explosion, which can damage the switchgear or even cause a safety accident.

[0009] Fourth, for gas-filled switchgear with line PT scheme, the PT current transformer is installed on the top of the gas box. Considering transportation factors, it often has to be installed on the project site. During the installation process, the operating space is small, the PT current transformer is heavy, the PT current transformer is inconvenient to install, and the installation is difficult.

[0010] Fifth, after the gas-insulated switchgear has been fully assembled, if it is necessary to replace the circuit breaker's solid-sealed pole, the operating space is small, the solid-sealed pole is heavy, and the replacement is difficult. Summary of the Invention

[0011] The purpose of this invention is to provide a gas-filled switchgear and system that can effectively solve the technical problem in the prior art where the switchgear uses compartment bushings to connect three-position switches and circuit breakers, resulting in a complex gas box structure and high gas box processing cost.

[0012] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0013] An air-insulated switchgear includes a cabinet, within which are a busbar compartment, a switch compartment, and a circuit breaker compartment. The busbar compartment houses busbars, the switch compartment houses switches, and the circuit breaker compartment houses circuit breaker poles. The invention also includes a three-position switch, which is fixedly mounted in the cabinet via side-mounted insulators. The three-position switch is directly connected to the circuit breaker poles installed in the circuit breaker compartment via copper busbars. The three-position switch seals the busbar compartment, switch compartment, and circuit breaker compartment within the same air chamber.

[0014] Furthermore, the copper busbar lap joints are provided with a plating structure.

[0015] The plating structure is a silver layer, and the copper busbar overlapping surfaces are silver-plated and then embossed.

[0016] Furthermore, pads are provided at the copper busbar lap surfaces to increase the contact area.

[0017] The busbar includes a busbar body and an extension busbar bushing. The extension busbar bushing is provided at both ends of the busbar body. The cross-section of the busbar body is a D-shaped structure.

[0018] Furthermore, in actual use, the busbar body is also equipped with a stationary contact of a disconnector switch.

[0019] In practical applications, traditional gas-insulated switchgear busbars use a copper busbar structure, which is wide and thin. It is bolted to the expansion busbar bushing. Due to the thinness of the copper busbar, the bolts and nuts are exposed, and their irregular tips can create localized high electric fields in the entire busbar system, thus affecting the product's insulation. This application makes an adaptive improvement to the copper busbar structure, changing the rectangular cross-section of the copper busbar to a "D" shaped structure. This structure results in a more uniform electric field and eliminates particularly high localized electric fields.

[0020] Further optimization involves installing a shielded disconnect switch inside the cabinet. The shielded disconnect switch includes a moving knife support frame, a moving knife contact spring, and moving contacts. The moving knife support frame has circular ends and clearance openings on its sides. A through slot perpendicular to the clearance openings is also provided on the side of the moving knife support frame. A support block is installed inside the moving knife support frame. Several moving contacts are installed inside the moving knife support frame and are slidably mounted on both sides of the support block. The two ends of the spring are connected to the moving contacts located at both ends of the support block. Under the action of the spring, the moving contacts move towards the center of the support block.

[0021] This ensures a tighter connection and improves conduction. The disconnector switch moving knife support bracket is used to connect to the insulated spindle inside the cabinet.

[0022] Existing disconnect switches mainly consist of a bracket, contact springs, support blocks, and moving blade conductors; the contact springs, support blocks, and moving blades extend beyond the bracket. Due to burrs and irregular chamfers on components such as the springs, support blocks, and moving blades, this structure easily forms localized sharp electric fields in high-voltage electric fields, leading to point discharge and reducing the product's insulation performance. In this application, the disconnect switch bracket is optimized and extended, rounded, and polished. The moving blade head adopts a ball-head structure. The improved structure places the springs, support blocks, and moving contacts all within the disconnect switch's moving blade support frame. The end of the disconnect switch's moving blade support frame has an arc-shaped structure, which optimizes the electric field and effectively improves the electric field uniformity of the disconnect switch.

[0023] The copper busbar has bolt shielding rings at both ends, and countersunk holes on the bolt shielding rings. The copper busbar includes a first copper busbar and a second copper busbar. The first copper busbar and the second copper busbar are located on both sides of the conductor and are in close contact with the conductor. The bolt shielding rings are located on both sides of the first copper busbar and the second copper busbar and correspond to the sides of the first copper busbar and the second copper busbar respectively. The bolt shielding rings located on both sides of the first copper busbar and the second copper busbar are connected by bolts.

[0024] Furthermore, several climbing skirts are provided on the insulating main shaft. The insulating main shaft has a hexagonal shaft structure.

[0025] In practical use, the climbing umbrella skirts are connected to form a one-piece structure.

[0026] Furthermore, a cable compartment is provided inside the cabinet, located below the circuit breaker compartment. There is a mounting plate between the cable compartment and the circuit breaker compartment, and a recessed sleeve is fixedly installed on the mounting plate. An inner conical sleeve is installed inside the recessed sleeve, and a current transformer is movably installed on the outside of the recessed sleeve.

[0027] The sunken sleeve is fixed to the mounting plate by welding.

[0028] Furthermore, the current transformer is movably mounted on the outside of the sunken sleeve via an adjustment mechanism.

[0029] Further optimization is achieved by incorporating a support plate, a lead screw, and a threaded sleeve into the adjustment mechanism. The support plate is slidably mounted on the mounting plate, the threaded sleeve is mounted on the support plate, and the lead screw is rotatably mounted on the support plate and engages with the threaded sleeve. Rotating the lead screw allows the support plate to move closer to or further away from the mounting plate. The current transformer is fixedly mounted on the support plate. In practical use, the position of the current transformer can be adjusted by adjusting the position of the support plate, thereby allowing for adjustment of the current transformer's installation height and ensuring that the cable remains within the protection range of the current transformer when inserted into the inner tapered sleeve.

[0030] Furthermore, in practical use, nitrogen is used for charging the gas-filled cabinet. In this application, the nitrogen is dried and then sealed in the gas-filled cabinet as an insulating medium for the primary main circuit. Nitrogen has stable chemical properties, is easy to obtain, does not have a greenhouse effect, and its decomposition products are non-toxic and will not cause secondary harm to maintenance personnel after the switchgear arcs.

[0031] Furthermore, in this application, the circuit breaker pole is disassembled and assembled using a circuit breaker pole auxiliary tooling, which includes a base plate, a top plate, and a pole guard plate. A driving mechanism is provided between the base plate and the top plate. The driving mechanism is used to drive the top plate to move closer to or away from the base plate. The pole guard plate is fixedly installed on the top plate, and rollers are provided on the base plate.

[0032] Furthermore, the driving mechanism is a hydraulic driving mechanism or a pneumatic driving mechanism, specifically a hydraulic cylinder or a pneumatic cylinder.

[0033] The driving mechanism includes a double-ended screw, two sets of first support frames, and two sets of second support frames. Each first and second support frame includes a first support rod and a second support rod. The first and second support rods are connected by a pivot shaft. The upper end of the first support rod is hinged to the top plate, and the lower end of the second support rod is hinged to the bottom plate. The pivot shaft has threaded holes. Both ends of the double-ended screw engage with the pivot shafts in the first and second support frames, respectively. In practical use, the top plate is driven by rotating the double-ended screw.

[0034] In practical applications, the drive mechanism can also be a jack.

[0035] In practical use:

[0036] 1) Place the auxiliary tooling under the circuit breaker pole to be removed;

[0037] 2) Crank the lifting jack to raise the top plate until it contacts the circuit breaker pole.

[0038] 3) Remove the fixing bolts of the circuit breaker pole;

[0039] 4) Reduce the height of the tooling;

[0040] 5) Transport the circuit breaker pole to the gas box and then inspect the assembly hole using the base plate rollers;

[0041] 6) Remove the faulty circuit breaker terminal;

[0042] To install a new circuit breaker pole, simply reverse the above steps.

[0043] Furthermore, a PT current transformer is installed on the enclosure, and the PT current transformer is installed using the following auxiliary installation structure;

[0044] The auxiliary installation structure includes a first bracket and a second bracket. The second bracket is vertically installed on the side of the first bracket. Both the first bracket and the second bracket are used to fix and connect to the cabinet. A support slide is provided on the second bracket. The support slide is slidably installed on the second bracket. A movable pulley assembly is provided on the support slide.

[0045] In practical use, the PT current transformer is hoisted by a movable pulley assembly. After the PT current transformer reaches the appropriate position, the position is adjusted by moving the support slide plate.

[0046] Furthermore, in actual use, a free first drive unit is set on the second bracket, which is used to drive the support slide plate to slide on the second bracket.

[0047] Furthermore, the support slide is slidably mounted on the second bracket via a sliding assembly.

[0048] Furthermore, the movable pulley assembly is specifically an electric hoist or a hand chain hoist.

[0049] Furthermore, the first support includes parallel uprights and several first crossbeams connecting the uprights. The uprights are slidably connected to the second support, and several second crossbeams connected to the cabinet are provided on the uprights.

[0050] Furthermore, the second support includes several third crossbeams and several fourth crossbeams, and the third crossbeams and fourth crossbeams are spliced ​​together to form the second support.

[0051] Furthermore, in practical use, the movable pulley assembly is slidably mounted on the support plate, allowing the movable pulley assembly to move on the support plate and adjust its position during the hoisting process.

[0052] In addition, the present invention also discloses an electrical system including an air-filled cabinet, wherein the air-filled cabinet is the air-filled cabinet described above.

[0053] Compared with the prior art, the present invention has the following beneficial effects:

[0054] This invention provides a three-position switch fixedly mounted inside a cabinet via side-mounted insulators. The three-position switch is directly connected to the circuit breaker poles via copper busbars. This invention allows the busbar compartment, switch compartment, and circuit breaker compartment to be sealed within the same gas chamber, simplifying the gas box structure, facilitating manufacturing, and reducing costs. This invention can also protect cable heads of current transformers. When a fault occurs at the cable head during power grid operation, it will prioritize de-energizing the cabinet in question, without affecting the normal power supply to other cabinets in the system. The tooling disclosed in this invention allows for the hoisting and installation of PT current transformers, facilitating assembly by installation personnel. This tooling is not only simple in structure, easy to manufacture, and low in cost, but also effectively improves work efficiency and reduces workload. Furthermore, this invention enables convenient disassembly and assembly of the circuit breaker poles. Attached Figure Description

[0055] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0056] Figure 1 is a schematic diagram of the overall structure of the present invention.

[0057] Figure 2 is a schematic diagram showing the positional relationship between the side-mounted insulator and the three-position switch of the present invention.

[0058] Figure 3 is a schematic diagram showing the positional relationship between the inner conical sleeve and the sinking sleeve of the present invention.

[0059] Figure 4 is a schematic diagram of the connection relationship between the cable and the inner conical sleeve of the present invention.

[0060] Figure 5 is a schematic diagram of the installation relationship between the climbing umbrella skirt and the insulating spindle of the present invention.

[0061] Figure 6 is a schematic diagram of the shielded disconnect switch of the present invention.

[0062] Figure 7 is a side view of Figure 6 of the present invention.

[0063] Figure 8 is a top view of Figure 6 of the present invention.

[0064] Figure 9 is a schematic diagram of the structure of the busbar of the present invention.

[0065] Figure 10 is a top view of Figure 9 of the present invention.

[0066] Figure 11 is a schematic diagram of the overall structure of the auxiliary tooling for the circuit breaker pole of the present invention.

[0067] Figure 12 is a schematic diagram of the overall structure of the auxiliary installation structure of the present invention.

[0068] Figure label:

[0069] 101 Cabinet, 102 Busbar Compartment, 103 Switch Compartment, 104 Circuit Breaker Compartment, 105 Busbar, 106 Three-Position Switch, 107 Side-Mounted Insulator, 108 Copper Busbar, 109 Circuit Breaker Pole, 110 Cable Compartment, 111 Current Transformer, 112 Mounting Plate, 113 Recessed Sleeve, 114 Inner Conical Sleeve, 115 Adjusting Mechanism, 116 Busbar Body, 117 Extended Busbar Bushing, 118 Disconnect Switch Stationary Contact, 119 Disconnect Switch Moving Knife Support Frame, 120 Moving Knife Contact Spring, 121 Moving Contact, 122 Through Slot, 123 Clearance Opening, 124 Bolt Shielding ring, 125 First copper busbar, 126 Second copper busbar, 127 Climbing umbrella skirt, 128 Insulating main shaft, 129 Base plate, 130 Top plate, 131 Pole post guard plate, 132 Drive mechanism, 133 First support frame, 134 Second support frame, 135 First support rod, 136 Third crossbeam, 137 Fourth crossbeam, 138 Second support rod, 139 Rotary shaft, 140 Double-ended screw, 141 First bracket, 142 Second bracket, 143 Electric hoist, 144 Support slide plate, 145 Sliding assembly, 146 Column, 147 First crossbeam, 148 Second crossbeam. Detailed Implementation

[0070] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the embodiments of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive. Embodiments of the invention will now be described in detail with reference to the accompanying drawings.

[0071] Referring to Figures 1 and 2, this embodiment discloses a gas-insulated switchgear, including a cabinet 101. The cabinet 101 contains a busbar compartment 102, a switch compartment 103, and a circuit breaker compartment 104. The busbar compartment 102 is used to house busbars 105, the switch compartment 103 is used to house switches, and the circuit breaker compartment 104 is used to house circuit breaker poles 109. This embodiment also includes a three-position switch 106, which is fixedly installed in the cabinet 101 by a side-mounted insulator 107. The three-position switch 106 is directly connected to the circuit breaker poles 109 installed in the circuit breaker compartment 104 by a copper busbar 108. The three-position switch 106 allows the busbar compartment 102, the switch compartment 103, and the circuit breaker compartment 104 to be sealed in the same gas chamber.

[0072] Furthermore, the overlapping surfaces of the copper busbar 108 are provided with a plating structure. The plating structure is a silver layer, and the overlapping surfaces of the copper busbar 108 are embossed after being silver-plated.

[0073] Furthermore, pads are provided at the lap joint surfaces of the copper busbar 108 to increase the contact area.

[0074] Furthermore, the copper busbar is equipped with columnar heat sinks, which effectively achieve the purpose of heat dissipation.

[0075] Furthermore, the cabinet 101 is equipped with a top sealing plate and a rear sealing plate. The top sealing plate and the rear sealing plate are made of aluminum plates. Replacing the stainless steel plates with aluminum plates can greatly improve heat dissipation efficiency and accelerate the flow of heat during switch operation.

[0076] Furthermore, a base is provided at the bottom of the cabinet 101, and the base is provided with heat dissipation holes. The base can accelerate air circulation and improve heat dissipation.

[0077] Furthermore, in actual use, both the top and rear sealing plates are equipped with several toothed heat dissipation plates.

[0078] In the prior art, a compartment bushing is used to connect the three-position switch 106 and the circuit breaker. In this application, a side-mounted insulator 107 is used for fixing, and the three-position switch 106 is directly connected to the circuit breaker pole 109 via a copper busbar 108. The advantage of this embodiment is that it can seal the busbar compartment 102, switch compartment 103, and circuit breaker compartment 104 in the same gas chamber, simplifying the gas box structure, facilitating manufacturing and processing, and reducing costs.

[0079] Furthermore, in some preferred embodiments, since the current transformer 111 in the gas-insulated switchgear is installed in the cable compartment 110, and the cable head is above the current transformer 111, the current transformer 111 cannot protect the cable head. When a fault occurs at the cable head during power grid operation, it can easily lead to a power outage of the entire system. Simultaneously, because the current transformer 111 in the existing gas-insulated switchgear is installed in the cable compartment 110, and the cable head is above the current transformer 111, the current transformer 111 cannot protect the cable head. When a fault occurs at the cable head during power grid operation, the insulation between the cable head and the inner cone (inner cone sleeve 114) at the overlap point breaks, forming an arc, causing combustion or even an explosion, thereby damaging the switchgear 101 or even causing a safety accident.

[0080] To solve the above technical problems, referring to Figures 3-5, in some preferred embodiments, a cable compartment 110 is provided inside the cabinet 101. The cable compartment 110 is located below the circuit breaker compartment 104. There is a mounting plate 112 between the cable compartment 110 and the circuit breaker compartment 104. A recessed sleeve 113 is fixedly installed on the mounting plate 112. An inner conical sleeve 114 is provided inside the recessed sleeve 113. A current transformer 111 is movably installed on the outside of the recessed sleeve 113.

[0081] The sunken sleeve 113 is fixedly mounted on the mounting plate 112 by welding.

[0082] Furthermore, the current transformer 111 is movably mounted on the outside of the sunken sleeve 113 via the adjustment mechanism 115.

[0083] Furthermore, in practical use, the adjusting mechanism 115 includes a support plate, a lead screw, and a threaded sleeve. The support plate is slidably mounted on the mounting plate 112, the threaded sleeve is mounted on the support plate, and the lead screw is rotatably mounted on the lead screw and engages with the threaded sleeve. After rotating the lead screw, the support plate can move closer to or further away from the mounting plate 112. The current transformer 111 is fixedly mounted on the support plate. In practical use, the position of the support plate can be adjusted to adjust the position of the current transformer 111, thereby adjusting the installation height of the current transformer 111 so that the cable is within the protection range of the current transformer 111 when inserted into the inner tapered sleeve 114.

[0084] In this embodiment, the installation position of the current transformer 111 is adjusted by the adjustment mechanism 115, enabling the current transformer 111 to protect the cable head. When a fault occurs at the cable head during power grid operation, the power supply to that cabinet 101 is de-energized first, without affecting the normal power supply to other cabinets 101 in the system. This system not only enables the current transformer 111 to protect the cable head, but also prevents arcing and improves safety.

[0085] Furthermore, in some preferred embodiments, referring to Figures 6-10, the busbar 105 includes a busbar body 116 and an extension busbar bushing 117. The extension busbar bushing 117 is provided at both ends of the busbar body 116, and the cross-section of the busbar body 116 is a D-shaped structure.

[0086] Furthermore, in some preferred embodiments, the busbar body 116 is also provided with a disconnector stationary contact 118.

[0087] In practical applications, the traditional gas-insulated switchgear busbar 105 uses a copper busbar 108 structure. The copper busbar 108 is a wide and thin structure, and its connection to the extended busbar bushing 117 is secured with bolts. Due to the thinness of the copper busbar 108, its bolts and nuts are exposed, and their irregular tips can create localized high electric fields in the entire busbar 105 system, thus affecting the product's insulation. This application makes an adaptive improvement to the copper busbar 108 of the busbar 105, changing its rectangular cross-section to a "D"-shaped structure. This structure results in a more uniform electric field and eliminates particularly high localized electric fields.

[0088] The existing knife-type disconnect switch mainly consists of a bracket, contact springs, support blocks, and moving blade conductors; its structure includes contact springs, support blocks, and moving blades extending from the bracket. Due to the presence of sharp burrs and irregular chamfers in components such as the springs, support blocks, and moving blades, this structure is prone to forming localized sharp electric fields in high-voltage electric fields, leading to point discharge and reducing the product's insulation performance.

[0089] Furthermore, in some preferred embodiments, a shielded disconnect switch is also installed inside the cabinet 101. The shielded disconnect switch includes a moving knife support frame 119, a moving knife contact spring 120, and moving contacts 121. The moving knife support frame 119 has circular ends and a clearance opening on its side. A through groove 122 perpendicular to the clearance opening 123 is provided on the side of the moving knife support frame 119. A support block is installed inside the moving knife support frame 119. Several moving contacts 121 are installed inside the moving knife support frame 119 and slidably mounted on both sides of the support block. The two ends of the spring are connected to the moving contacts 121 located at both ends of the support block. Under the action of the spring, the moving contacts 121 move towards the center of the support block to ensure a tighter contact and improve the conduction effect. The moving knife support frame 119 is used to connect to the insulated main shaft 128 inside the cabinet 101.

[0090] In this application, the support of the disconnecting switch is optimized and extended, and rounded and polished. The moving blade head adopts a ball head structure. The improved structure places the spring, support block and moving contact 121 inside the disconnecting switch moving blade support frame 119. The end of the disconnecting switch moving blade support frame 119 has an arc-shaped structure, which can optimize the electric field and effectively improve the electric field uniformity of the disconnecting switch.

[0091] Furthermore, in some preferred embodiments, bolt shielding rings 124 are provided at both ends of the copper busbar 108. The bolt shielding rings 124 are provided with countersunk holes. The copper busbar 108 includes a first copper busbar 125 and a second copper busbar 126. The first copper busbar 125 and the second copper busbar 126 are located on both sides of the conductor and are in close contact with the conductor. The bolt shielding rings 124 are located on both sides of the first copper busbar 125 and the second copper busbar 126 and correspond to the sides of the first copper busbar 125 and the second copper busbar 126 respectively. The bolt shielding rings 124 located on both sides of the first copper busbar 125 and the second copper busbar 126 are connected by bolts. Traditional copper busbar 108 lap joints and copper busbar 108 and bushing lap joints are directly connected by bolts. After the bolt heads, spring flat washers and nuts are tightened, sharp burrs will be formed, which will affect the conductor electric field of the entire main circuit. In this application, a lap shielding ring structure is adopted, and a locking bolt is used to connect the copper busbar 108 and the conductor. After the connection is completed, the bolt heads and spring flat washers are completely embedded in the countersunk holes in the shielding ring, which can effectively improve the uniformity of the entire electric field.

[0092] Furthermore, the insulating main shaft 128 is provided with several climbing skirts 127. The insulating main shaft 128 is a hexagonal shaft structure.

[0093] In practical applications, the creeper skirts 127 form an integrated structure after connection. The insulation capacity of a conventional disconnector switch drive shaft primarily depends on the insulation performance of the material itself and its surface. In this application, the insulated spindle 128 is improved by incorporating several creeper skirts 127, which significantly increases the surface insulation performance of the drive shaft and reduces the risk of surface insulation failure due to contamination or other factors.

[0094] Furthermore, in practical use, nitrogen is used for charging the gas-filled cabinet. In this application, the nitrogen is dried and then sealed in the gas-filled cabinet as an insulating medium for the primary main circuit. Nitrogen has stable chemical properties, is easy to obtain, does not have a greenhouse effect, and its decomposition products are non-toxic and will not cause secondary harm to maintenance personnel after the switchgear arcs.

[0095] Furthermore, since the gas-insulated switchgear is difficult to replace if the circuit breaker pole 109 needs to be replaced after the overall assembly is completed, the operating space is small and the circuit breaker pole 109 is heavy. In some preferred embodiments, auxiliary tooling for disassembly and assembly of the circuit breaker pole 109 is used, as shown in Figure 11. It includes a base plate 129, a top plate 130, and a pole guard plate 131. A driving mechanism 132 is provided between the base plate 129 and the top plate 130. The driving mechanism 132 is used to drive the top plate 130 to move closer to or away from the base plate 129. The pole guard plate 131 is fixedly installed on the top plate 130, and rollers are provided on the base plate 129.

[0096] Furthermore, the drive mechanism 132 is a hydraulic drive mechanism 132 or a pneumatic drive mechanism 132, specifically a hydraulic cylinder or a pneumatic cylinder.

[0097] In this embodiment, the drive mechanism 132 includes a double-ended screw 140, two sets of first support frames 133, and two sets of second support frames 134. Each of the first support frames 133 and 134 includes a first support rod 135 and a second support rod 138. The first support rod 135 and the second support rod 138 are connected by a pivot 139. The upper end of the first support rod 135 is hinged to the top plate 130, and the lower end of the second support rod 138 is hinged to the bottom plate 129. The pivot 139 has a threaded hole. Both ends of the double-ended screw 140 engage with the pivot 139 in the first support frame 133 and the second support frame 134, respectively. In actual use, the top plate 130 is driven by rotating the double-ended screw 140.

[0098] In practical use, the drive mechanism 132 can also be a jack.

[0099] In practical use:

[0100] 1) Place the auxiliary tooling below the circuit breaker pole 109 that needs to be removed;

[0101] 2) Crank the lifting jack to raise the top plate 130 until it contacts the pole.

[0102] 3) Remove the fixing bolts 109 of the circuit breaker pole;

[0103] 4) Reduce the height of the tooling;

[0104] 5) Use the rollers on the base plate 129 to transport the circuit breaker pole 109 to the inspection and assembly hole behind the gas box;

[0105] 6) Remove the faulty circuit breaker pole 109;

[0106] To install a new circuit breaker pole 109, simply reverse the above steps.

[0107] During the disassembly and assembly of the circuit breaker pole 109, the tooling can support and transport the circuit breaker pole 109, facilitating the smooth removal and replacement of the circuit breaker pole 109 by construction personnel. The tooling can be raised and lowered to adjust its height, adapting to the disassembly and assembly of the tooling; the tooling can be easily moved, facilitating the transport of the circuit breaker pole 109.

[0108] Furthermore, in actual use, the cabinet is also equipped with guide grooves corresponding to the rollers to control the movement and facilitate positioning operations during disassembly and assembly.

[0109] Furthermore, in some preferred embodiments, a PT current transformer is installed on the enclosure, and the PT current transformer is installed using the following auxiliary installation structure;

[0110] Referring to Figure 12, the auxiliary installation structure includes a first bracket 141 and a second bracket 142. The second bracket 142 is vertically installed on the side of the first bracket 141. Both the first bracket 141 and the second bracket 142 are used to fix and connect to the cabinet 101. A support slide plate 144 is provided on the second bracket 142. The support slide plate 144 is slidably installed on the second bracket 142. A movable pulley assembly is provided on the support slide plate 144.

[0111] In practical use, the PT current transformer is hoisted by the set movable pulley assembly. After the PT current transformer reaches the appropriate position, the position is adjusted by moving the support slide plate 144.

[0112] Furthermore, in actual use, a free first drive unit is provided on the second bracket 142, which is used to drive the support slide plate 144 to slide on the second bracket 142.

[0113] Furthermore, the support slide plate 144 is slidably mounted on the second bracket 142 via the sliding assembly 145.

[0114] Furthermore, the movable pulley assembly is specifically an electric hoist 143 or a hand chain hoist.

[0115] Furthermore, the first support 141 includes parallel uprights 146 and a plurality of first crossbeams 147 connecting the uprights 146. The uprights 146 are slidably connected to the second support 142, and a plurality of second crossbeams 148 connected to the cabinet 101 are provided on the uprights 146.

[0116] Furthermore, the second support 142 includes several third crossbeams 136 and several fourth crossbeams 137, and the third crossbeams 136 and the fourth crossbeams 137 are spliced ​​together to form the second support 142.

[0117] Furthermore, in actual use, the movable pulley assembly is slidably mounted on the support plate 144, enabling the movable pulley assembly to move on the support plate 144 and adjust its position during hoisting.

[0118] The auxiliary installation structure allows for the hoisting and installation of PT current transformers, facilitating assembly by installation personnel. This fixture is not only simple in structure and easy to manufacture, but also low in cost, effectively improving work efficiency and reducing workload.

[0119] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0120] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. It should be noted that any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A gas-insulated switchgear, comprising a cabinet, wherein a busbar compartment, a switch compartment, and a circuit breaker compartment are disposed within the cabinet, the busbar compartment for housing busbars, the switch compartment for housing switches, and the circuit breaker compartment for housing circuit breaker poles, characterized in that: It also includes a three-position switch, which is fixedly installed in the cabinet by side-mounted insulators. The three-position switch is directly connected to the circuit breaker pole installed in the circuit breaker compartment by copper busbars. The three-position switch makes the busbar compartment, switch compartment and circuit breaker compartment sealed in the same air chamber. The copper busbar lap surface is provided with a plating structure, and a pad is provided at the copper busbar lap surface to increase the contact area. A columnar heat sink is provided on the copper busbar to achieve the purpose of heat dissipation.

2. The gas-filled cabinet according to claim 1, characterized in that: The busbar includes a busbar body and an extension busbar bushing. The extension busbar bushing is provided at both ends of the busbar body. The cross-section of the busbar body is a D-shaped structure.

3. The gas-filled cabinet according to claim 2, characterized in that: The cabinet also houses a shielded disconnect switch, which includes a moving knife support frame, a moving knife contact spring, and moving contacts. The moving knife support frame has circular ends and clearance openings on its sides. A through slot perpendicular to the clearance openings is also provided on the side of the moving knife support frame. A support block is installed inside the moving knife support frame. Several moving contacts are installed inside the moving knife support frame and slidably mounted on both sides of the support block. The two ends of the spring are connected to the moving contacts located at both ends of the support block. Under the action of the spring, the moving contacts move towards the center of the support block.

4. The gas-filled cabinet according to claim 3, characterized in that: The copper busbar has bolt shielding rings at both ends, and countersunk holes on the bolt shielding rings. The copper busbar includes a first copper busbar and a second copper busbar. The first copper busbar and the second copper busbar are located on both sides of the conductor and are in close contact with the conductor. The bolt shielding rings are located on both sides of the first copper busbar and the second copper busbar and correspond to the sides of the first copper busbar and the second copper busbar respectively. The bolt shielding rings located on both sides of the first copper busbar and the second copper busbar are connected by bolts.

5. The gas-filled cabinet according to claim 1, characterized in that: The cabinet contains a cable compartment located below the circuit breaker compartment. There is a mounting plate between the cable compartment and the circuit breaker compartment. A recessed sleeve is fixedly mounted on the mounting plate. An inner conical sleeve is installed inside the recessed sleeve. A current transformer is movably mounted on the outside of the recessed sleeve.

6. The gas-filled cabinet according to claim 5, characterized in that: The current transformer is movably mounted on the outside of the sunken sleeve via an adjustment mechanism.

7. The gas-insulated cabinet according to claim 6, characterized in that: The adjustment mechanism includes a support plate, a lead screw, and a threaded sleeve. The support plate is slidably mounted on the mounting plate, the threaded sleeve is mounted on the support plate, and the lead screw is rotatably mounted on the lead screw and engages with the threaded sleeve. After rotating the lead screw, the support plate can move closer to or further away from the mounting plate. The current transformer is fixedly mounted on the support plate. By adjusting the position of the support plate, the position of the current transformer can be adjusted, so that the installation height of the current transformer can be adjusted, ensuring that the cable is within the protection range of the current transformer when inserted into the inner tapered sleeve.

8. The gas-filled cabinet according to claim 1, characterized in that: The circuit breaker pole is assembled and disassembled using a circuit breaker pole auxiliary tooling, which includes a base plate, a top plate, and a pole guard plate. A driving mechanism is provided between the base plate and the top plate. The driving mechanism is used to drive the top plate to move closer to or away from the base plate. The pole guard plate is fixedly installed on the top plate, and rollers are provided on the base plate.

9. A gas-filled cabinet according to claim 8, characterized in that: The driving mechanism includes a double-ended screw, two sets of first support frames and two sets of second support frames. Each of the first and second support frames includes a first support rod and a second support rod. The first support rod and the second support rod are connected by a rotating shaft. The upper end of the first support rod is hinged to the top plate, and the lower end of the second support rod is hinged to the bottom plate. The rotating shaft is provided with a threaded hole. The two ends of the double-ended screw are respectively engaged with the rotating shaft in the first and second support frames.

10. An electrical system, characterized in that: Includes an air-filled cabinet, wherein the air-filled cabinet is an air-filled cabinet as described in any one of claims 1-9.

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