An environmentally friendly gas-insulated ring main unit

Abstract

The present invention discloses an environmentally friendly gas-insulated ring main unit, which includes a cabinet body, a three-position switch, a three-position mechanism, a circuit breaker main circuit and a circuit breaker mechanism. The three-position switch, the three-position mechanism, the circuit breaker main circuit and the circuit breaker mechanism are installed in the cabinet body. An interlock device is connected between the three-position mechanism and the circuit breaker mechanism to prevent the three-position mechanism from being operated under live conditions. The three-position switch includes an insulating main shaft, and the indicating device includes an indicating main shaft. The insulating main shaft is connected to the indicating main shaft. The present invention optimizes the traditional three-position structure, increases the switch depth, and ensures the phase-to-phase and phase-to-ground distances of the isolating switch; designs an isolating switch structure suitable for the use of environmentally friendly gas to ensure qualified temperature rise; for the conductive standard parts on the isolating switch, electric field equalizing fittings are designed to make the standard parts meet the insulation requirement level specified by the state.

Description

Technical Field

[0001] The present invention belongs to the field of environmentally friendly gas-insulated ring main units, and relates to an environmentally friendly gas-insulated ring main unit. Background Art

[0002] Since the 1950s, the development of medium-voltage switchgear has gone through stages such as open type, box type, and metal-enclosed type. There are no problems in meeting the functional requirements of the equipment, and the products have long been serialized and fully covered in terms of usage scope. Currently, innovation and technological progress mainly focus on continuously meeting the market, social, and era demands for switchgear in terms of safety, reliability, miniaturization, environmental protection, etc.

[0003] Continuing to use SF6 as the insulating gas will cause a significant increase in environmental costs and social costs in the future. Therefore, reducing, restricting, or even banning SF6 gas in the power system is an inevitable trend in the development of power grid equipment.

[0004] With the continuous progress and improvement of breaking and insulation technologies, the development of environmentally friendly gas-insulated metal-enclosed switchgear has been theoretically and technically mature. Products produced by domestic equipment manufacturing enterprises have passed type tests and been put into operation on the grid. However, currently, most of the core environmentally friendly components on the market use epoxy resin to wrap the live parts or use insulating plates to isolate the live bodies to achieve the insulation effect; their structures are complex and the costs are relatively high. Summary of the Invention

[0005] In order to overcome the deficiencies of the prior art, the present invention provides an environmentally friendly gas-insulated ring main unit.

[0006] To achieve the above object, the present invention adopts the following technical solutions: An environmentally friendly gas-insulated ring main unit, characterized in that: it includes a cabinet body, a three-position switch, a three-position mechanism, a breaker main circuit, and a breaker mechanism. The three-position switch, the three-position mechanism, the breaker main circuit, and the breaker mechanism are installed in the cabinet body. An interlock device is connected between the three-position mechanism and the breaker mechanism to prevent live operation of the three-position mechanism. The three-position switch includes an insulating main shaft, and the indicating device includes an indicating main shaft. The insulating main shaft is connected to the indicating main shaft.

[0007] Furthermore; the cabinet body includes a gas box, an instrument room, and a cabinet frame. An mechanism room and a cable room are configured inside the cabinet frame. An inflatable compartment is arranged inside the gas box. The breaker mechanism and the three-position mechanism are installed in the mechanism room. The three-position switch and the breaker main circuit are installed in the inflatable compartment. The breaker mechanism is connected to the breaker main circuit, and the three-position switch is connected to the three-position mechanism.

[0008] Furthermore, the three-position switch includes a three-position bracket, an insulating main shaft, and a closing and opening mechanism. The insulating main shaft and the closing and opening mechanism are installed on the three-position bracket. The insulating main shaft is linked with the closing and opening mechanism. The closing and opening mechanism includes a shielding ring and a shielding cover, and the shielding ring and the shielding cover are used for temperature rise control and electric field voltage equalization.

[0009] Furthermore, the three-position mechanism includes a three-position frame and a cam disc. The cam disc is fixedly arranged on the insulating main shaft of the three-position switch. An isolating output device, an isolating transmission device, a grounding output device, a grounding transmission device, and an energy storage device are installed on the three-position frame. The isolating transmission device and the grounding transmission device are linked with the cam disc and respectively output closing and opening torques and grounding torques to the insulating main shaft through the cam disc.

[0010] Furthermore, the main circuit of the circuit breaker includes a main circuit frame of the circuit breaker. An arc extinguishing chamber assembly and a main circuit power assembly are installed on the main circuit frame of the circuit breaker. The arc extinguishing chamber assembly includes an arc extinguishing contact seat. The arc extinguishing contact seat includes an integrally formed arc extinguishing contact seat column and an arc extinguishing contact seat surface. The main circuit power assembly includes a bracket shielding ring. The arc extinguishing contact seat and the bracket shielding ring are used for electric field equalization around.

[0011] Furthermore, the interlocking device includes a circuit breaker interlocking plate and a three-position interlocking plate. The three-position interlocking plate is connected with the three-position mechanism. The circuit breaker mechanism controls the circuit breaker interlocking plate through a buckle device to restrict the movement of the three-position interlocking plate.

[0012] Furthermore, the indicating device includes an indicating plate. The indicating main shaft is connected with the indicating plate, and the indicating plate is used for displaying the state of the three-position switch.

[0013] Furthermore, the closing and opening mechanism includes three-phase upper insulators, three-phase lower insulators, and a transmission component. The three-phase upper insulators are fixedly arranged on the three-position bracket. A closing and grounding contact seat is fixedly arranged on the bus bar. The three-phase lower insulators are fixedly arranged on the three-position bracket. A transition row is fixedly arranged on the three-phase lower insulators. An arc extinguishing chamber contact seat is fixedly arranged on the transition row. The transmission component includes a connecting rod structure. The connecting rod structure includes a transmission crank arm, a moving knife pull rod, and a moving knife pull plate. The transmission crank arm is fixedly arranged on the insulating main shaft. There are two groups of moving knife pull rods and they are symmetrically arranged. The two ends of the moving knife pull rod are respectively rotationally connected with the transmission crank arm and the moving knife pull plate. Nylon pins located on both sides of the transmission crank arm are fixedly arranged on the insulating main shaft to restrict the movement of the transmission crank arm.

[0014] Furthermore, the transmission component further includes isolating knives. There are two groups of isolating knives. The two groups of isolating knives are arranged in parallel and fixedly connected through a first knife support and a second knife support. A connecting rod located between the first knife support and the second knife support is also fixedly arranged on the two groups of isolating knives. The connecting rod is rotationally connected with the moving knife pull plate. A first contact point located at the knife head and a second contact point located at the knife tail are fixedly arranged on the isolating knife. The second contact point contacts or separates from the arc extinguishing chamber contact seat.

[0015] Furthermore, the arc extinguishing contact seat column is vertically installed on the arc extinguishing contact seat surface member. The arc extinguishing contact seat surface member is provided with an arc extinguishing contact seat hole, and the arc extinguishing contact seat hole is opposite to the support plate mounting hole on the arc extinguishing chamber support plate. The first fixing member is inserted into the arc extinguishing contact seat hole and the support plate mounting hole to fixedly connect the arc extinguishing contact seat and the arc extinguishing chamber support plate.

[0016] In summary, the advantages of the present invention are as follows:

[0017] 1), The present invention optimizes the traditional three-position structure, increases the switch depth, and ensures the phase-to-phase and phase-to-ground distances of the isolating switch; designs an isolating switch structure suitable for the use of environmental protection gas to ensure qualified temperature rise; for the conductive standard parts on the isolating switch, by designing an electric field equalizing fitting, the standard parts meet the insulation requirement level stipulated by the state.

[0018] 2), The present invention optimizes the main circuit structure of the original sulfur hexafluoride circuit breaker, improves the processing technology requirements, rounds and edges the parts, and polishes the surface; designs a special arc extinguishing chamber contact seat and an electric field equalizing fitting, so that the main circuit of the environmental protection circuit breaker can achieve the same performance as the main circuit of the sulfur hexafluoride circuit breaker without using epoxy resin and insulating plates.

[0019] 3), The present invention redesigns the main circuit structure and the isolating three-position structure of the circuit breaker, improves the processing technology level, so that the main circuit of the environmental protection circuit breaker and the three-position switch can achieve the same performance as the main circuit of the sulfur hexafluoride circuit breaker and the three-position switch without using epoxy resin and insulating plates.

[0020] 4), The present invention cooperates with a special isolating mechanism and a circuit breaker mechanism to realize the opening and closing operation functions of the switch; is equipped with an overall cabinet frame structure to form a complete environmental protection gas-insulated ring main switchgear system.

[0021] 5), The present invention designs a double-headed screw to realize the functions of adjusting the opening distance and overtravel of the vacuum bubble, solves the problem that the coarse-thread screw cannot accurately adjust the opening distance, and at the same time, because the fine-thread screw has better self-locking performance, improves the mechanical stability of the main circuit of the circuit breaker.

[0022] 6), The present invention designs the surface of the support shielding ring, the support busbar and the arc extinguishing contact seat to be rounded, without edges and corners, so that the parts themselves ensure a uniform electric field when energized, achieving the purpose of improving the insulation performance of the main circuit of the circuit breaker.

[0023] 7), The present invention designs a method of driving a cam disk by an isolation drive device and a grounding drive device to output closing and opening torques and grounding torques to an insulating main shaft. The structure is simple, the operation is convenient, the transmission efficiency is high, the overall structure design of the three-position switch operating mechanism is reasonable and reliable, the stability is high, and the service life is long; the isolation output device and the grounding output device of the present invention are interlocked to ensure that the three-position switch operating mechanism can only perform closing or grounding operations in the isolated state, preventing operations of grounding during closing or closing during grounding.

[0024] 8), The present invention designs an interlock device between the three-position mechanism and the circuit breaker mechanism to achieve the purpose of preventing the operation of the three-position mechanism when the main circuit of the circuit breaker is in the closed state, ensuring the safety of the ring main unit and the operator; the present invention designs a buckle notch 511 on the circuit breaker indicating main shaft 51, and the state of the main circuit of the circuit breaker controls the different rotations of the circuit breaker indicating main shaft to cause the buckle notch to interfere with or disengage from the first buckle plate and the second buckle plate, realizing locking and unlocking. The present invention realizes the interlock function through optimizing the design of its own structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the internal device installation of the environmentally friendly gas-insulated ring main unit of the present invention.

[0026] Figure 2 It is a schematic diagram of the three-position switch of the present invention.

[0027] Figure 3 It is a shielding schematic diagram of the present invention.

[0028] Figure 4 It is a shielding ring schematic diagram of the present invention.

[0029] Figure 5 It is a schematic diagram of the isolating knife of the present invention Figure 1 。

[0030] Figure 6 It is a schematic diagram of the isolating knife of the present invention Figure 2 。

[0031] Figure 7 It is a schematic diagram of the transmission component of the present invention.

[0032] Figure 8 It is a schematic diagram of the three-position mechanism of the present invention Figure 1 。

[0033] Figure 9 It is a schematic diagram of the three-position mechanism of the present invention Figure 2 。

[0034] Figure 10 It is a schematic diagram of the cam disk of the present invention.

[0035] Figure 11 Schematic diagram of the second mechanism board of the present invention.

[0036] Figure 12 Schematic diagram of the isolation drive crank arm of the present invention.

[0037] Figure 13 Schematic diagram of the grounding drive crank arm of the present invention.

[0038] Figure 14 Schematic diagram of the indicating device of the present invention.

[0039] Figure 15 Schematic of the main circuit of the circuit breaker of the present invention Figure 1 .

[0040] Figure 16 Schematic of the main circuit of the circuit breaker of the present invention Figure 2 .

[0041] Figure 17 Schematic diagram of the arc extinguishing contact base of the present invention.

[0042] Figure 18 Schematic diagram of the double-headed screw of the present invention.

[0043] Figure 19 Schematic diagram of the interlocking device of the present invention.

[0044] Figure 20 Installation schematic diagram of the interlocking device of the present invention.

[0045] Figure 21 is Figure 20 an enlarged schematic diagram of A in. Specific embodiments

[0046] The following specific examples illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0047] It should be noted that the drawings provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Therefore, only the components related to the present invention are shown in the drawings, rather than being drawn according to the number, shape, and size of the components in actual implementation. The types, quantities, and proportions of the components in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0048] In the embodiments of the present invention, all directional indications (such as up, down, left, right, front, back, horizontal, vertical, etc.) are only used to explain the relative positional relationship, movement conditions, etc. between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0049] Embodiment 1:

[0050] As Figure 1 - 21 shown, an environmentally friendly gas-insulated ring main unit includes a cabinet body 1, a three-position switch 2, a three-position mechanism 3, a circuit breaker main circuit 4, and a circuit breaker mechanism 5. The three-position switch 2, the three-position mechanism 3, the circuit breaker main circuit 4, and the circuit breaker mechanism 5 are installed in the cabinet body 1. An interlock device 6 is connected between the three-position mechanism 3 and the circuit breaker mechanism 5 to prevent the three-position mechanism 3 from being operated when energized. The three-position switch 2 is connected with an indicating device 9 for displaying the three-position state.

[0051] The cabinet body 1 includes a gas tank 11, an instrument room 12, and a cabinet frame 13. An operating mechanism room 131 and a cable room 132 are arranged in the cabinet frame 13. An inflatable compartment 111 is arranged in the gas tank 11. The circuit breaker mechanism 5 and the three-position mechanism 3 are installed in the operating mechanism room 11. The three-position switch 2 and the circuit breaker main circuit 4 are installed in the inflatable compartment 111. The circuit breaker mechanism 5 is connected with the circuit breaker main circuit 4, and the three-position switch 2 is connected with the three-position mechanism 3 to realize the opening and closing functions of the switch.

[0052] Three-phase insulating bushings 7 are installed above the inflatable compartment 111. From top to bottom, the inflatable compartment 111 is successively the three-phase insulating bushings 7, the three-position switch 2, and the circuit breaker main circuit 4. The three-phase insulating bushings 7 are connected with the three-position switch 2 through a main bus assembly 71. The three-position switch 2 is interlocked with the circuit breaker main circuit 4. The lower part of the circuit breaker main circuit 4 is connected to the cable room 132 through a branch bus assembly 44. An explosion-proof plate 112 is fixedly arranged on the bottom plate of the gas tank 11.

[0053] The instrument room is used to install secondary wires and secondary components, such as opening and closing buttons, indicator lights, microcomputer protection devices, ammeters and voltmeters, etc. It is a gathering place for the secondary line terminals of the environmentally friendly gas-insulated ring main unit, which is convenient for secondary line inspection and after-sales maintenance. The microcomputer protection device can enable users to remotely query the opening and closing states of the switch according to the opening and closing signals of the travel switches on the mechanism, and remotely control the opening and closing of the switch. At the same time, in cooperation with detection components such as current transformers, it can intelligently judge faults on the line and control the switch to eliminate faults or give feedback to the background.

[0054] As Figure 2 - 7As shown, the three-position switch 2 includes a three-position bracket 21, an insulating main shaft 22, and a closing and opening mechanism 23. The insulating main shaft 22 and the closing and opening mechanism 23 are installed on the three-position bracket 21. The insulating main shaft 22 is linked with the closing and opening mechanism 23. The closing and opening mechanism 23 includes a shielding ring 232 and a shielding cover 233, which are used for temperature rise control and electric field voltage equalization.

[0055] The three-position bracket 21 is composed of a front bracket plate 211, a rear bracket plate 212, a first cross beam 213, a second cross beam 214, and a fourth cross beam 215. The first cross beam 213, the second cross beam 214, and the fourth cross beam 215 are horizontally arranged in parallel and fixed between the front bracket plate 211 and the rear bracket plate 212. The front bracket plate 211 and the rear bracket plate 212 are fixedly connected to the gas tank 11. The insulating main shaft 22 is horizontally arranged. The output end of the insulating main shaft 22 is rotatably connected to the rear bracket plate 212. The input end of the insulating main shaft 22 passes through the front bracket plate 211 and is movably sealed 25 connected to the front bracket plate 211.

[0056] The closing and opening mechanism 23 includes three-phase upper insulators 230, three-phase lower insulators 231, and a transmission assembly. The three-phase upper insulators 230 are fixed on the first cross beam 213. A bus bar 2301 is fixed on the three-phase upper insulators 230. The bus bar 2301 is fixedly connected to the three-phase insulating bushing 7. A closing and grounding contact seat 2302 is fixed on the bus bar 2301. The three-phase lower insulators 231 are fixed on the second cross beam 214. A transition row 2311 is fixed on the three-phase lower insulators 231. An arc extinguishing chamber contact seat 2312 is fixed on the transition row 2311.

[0057] The transmission assembly further includes a connecting rod structure. The connecting rod structure includes a transmission crank arm 2341, a moving knife pull rod 2342, and a moving knife pull plate 2343. The transmission crank arm 2341 is fixed on the insulating main shaft 22. There are two groups of moving knife pull rods 2342, which are symmetrically arranged. The two ends of the moving knife pull rod 2342 are respectively rotatably connected to the transmission crank arm 2341 and the moving knife pull plate 2343. Nylon pins 2340 located on both sides of the transmission crank arm 2341 are fixed on the insulating main shaft 22 to further limit the movement of the transmission crank arm 2341.

[0058] The transmission assembly further includes isolation knives 235. There are two sets of isolation knives 235, which are arranged in parallel and fixedly connected through a first knife support 2351 and a second knife support 2356. A connecting rod 2357 located between the first knife support 2351 and the second knife support 2356 is also fixedly installed on the two sets of isolation knives 235. The connecting rod 2357 is rotatably connected to the moving knife pull plate 2343. The isolation knife 235 includes a first side surface 2358 and a second side surface 2359. The first side surfaces 2358 of the two sets of isolation knives 235 face each other, and the second side surfaces 2359 face away from each other. On the first side surface 2358 of the isolation knife 235, a first contact point 2355 located at the knife tip and a second contact point 2354 located at the knife tail are fixedly installed to contact or separate from the arc extinguishing chamber contact seat 2312.

[0059] The shielding cover 233 is fixedly installed at the knife tip of the isolation knife 235. Specifically, the shielding cover 233 is provided with a stepped shielding cover mounting hole 2331. The first knife support 2351 penetrates through the shielding cover mounting hole 2331, and standard parts are arranged at both ends to fixedly connect the shielding cover 233 and the first knife support 2351. The standard parts are wrapped inside the shielding cover 233 through the shielding cover mounting hole 2331, achieving the purpose of evenly isolating the electric field around the isolation knife 235 and reducing the phase-to-phase insulation clear distance. In this embodiment, the shielding cover 233 is fixedly installed at the knife tip of the isolation knife 235, which can increase the heat dissipation area of the isolation knife 235, thereby improving the temperature rise margin at the closing grounding contact seat 2302 and the isolation knife 235.

[0060] The shielding ring 232 is installed at the knife tail of the isolation knife 235 through a second standard part 2322. The second standard part 2322 is rotatably connected to the arc extinguishing chamber contact seat 2312. The shielding ring 232 is fixedly provided with a shielding ring mounting hole 2321. The second standard part 2322 is located inside the shielding ring mounting hole 2321. The second standard part 2322 is wrapped inside the shielding ring 232 through the shielding ring mounting hole 2321, achieving the purpose of evenly isolating the electric field around the isolation knife 235 and reducing the phase-to-phase insulation clear distance. In this embodiment, the shielding ring 232 is installed at the knife tail of the isolation knife 235, which can increase the heat dissipation area of the isolation knife 235, thereby improving the temperature rise margin at the arc extinguishing chamber contact seat 2312 and the isolation knife 235.

[0061] The transmission assembly further includes a contact seat assembly 236. The contact seat assembly 236 includes a grounding bar 2361 and a grounding contact seat 2362. The grounding bar 236 is fixedly installed on the fourth cross beam 215. There are three sets of grounding bars 2361. The grounding contact seat 2362 is inserted between the two sets of isolation knives 235. Both sides of the grounding contact seat 2362 contact or separate from the first contact point 2355.

[0062] The surfaces of the shielding cover 233, the shielding ring 232, and the isolation knife 235 are treated with rounded corners, no edges, and no sharp corners, so as to ensure a uniform electric field when the parts are energized, achieving the purpose of improving the insulation performance of the main circuit.

[0063] During the implementation of the three-position switch 2, when the three-position mechanism 3 performs a tripping operation, it drives the insulating main shaft 22 to rotate. The insulating main shaft 22 drives the transmission assembly to rotate, separating the isolating knife 235 from the grounding bar 2361 and keeping it in the isolating position. At this time, the insulation clearance on the side shell of the gas tank is increased.

[0064] The three-position switch 2 can be individually moved into an existing ring main unit.

[0065] As Figure 8 - 13 shown, the three-position mechanism 3 includes a three-position frame 31 and a cam disk 32. The cam disk 32 is fixedly arranged on the insulating main shaft 22. An isolating output device, an isolating transmission device, a grounding output device, a grounding transmission device, and an energy storage device are installed on the three-position frame 31. The isolating output device and the grounding output device are respectively linked with the energy storage device and control the energy storage of the energy storage device. The isolating transmission device and the grounding transmission device are linked with the cam disk 32 and respectively output closing-opening torque and grounding torque to the insulating main shaft 22 through the cam disk 32.

[0066] The three-position frame 31 includes a first mechanism plate 311 and a second mechanism plate 312. The first mechanism plate 311 is located at the operation input end of the three-position mechanism 3, and the second mechanism plate 312 is located at the operation output end of the three-position mechanism 3. The first mechanism plate 311 and the second mechanism plate 312 are fixedly connected by a three-position support column 313. Generally, the first mechanism plate 311 and the second mechanism plate 312 are arranged in parallel. The second mechanism plate 312 is fixedly connected to the partition of the mechanism chamber 131 through a fixed support column 324, thereby installing the three-position mechanism 3 in the mechanism chamber 131.

[0067] The isolating output device includes an isolating output shaft 33. The input end of the isolating output shaft 33 rotatably penetrates the first mechanism plate 311, and an isolating cam sleeve 331 is fixedly sleeved on the input end of the isolating output shaft 33 outside the first mechanism plate 311.

[0068] The grounding output device includes a grounding output shaft 34. The input end of the grounding output shaft 34 rotatably penetrates the first mechanism plate 311, and a grounding cam sleeve 341 is fixedly sleeved on the input end of the grounding output shaft 34 outside the first mechanism plate 311.

[0069] The energy storage device includes an isolated energy storage crank arm 351, a grounded energy storage crank arm 352, and an energy storage compression spring 353. The isolated energy storage crank arm 351 is fixedly arranged on the isolated output shaft 33 and can rotate with the isolated output shaft 33. An isolated transmission pin 3511 is provided at the free end of the isolated energy storage crank arm 35. The grounded energy storage crank arm 352 is fixedly arranged on the grounded output shaft 34 and can rotate with the grounded output shaft 34. A grounded transmission pin 3521 is provided at the free end of the grounded energy storage crank arm 352. Spring heads 3531 are provided at both ends of the energy storage compression spring 353, and the spring heads 3531 are respectively rotatably connected to the isolated transmission pin 3511 and the grounded transmission pin 3521. An energy storage telescopic rod 3532 is arranged between the two groups of spring heads 3531. When the energy storage compression spring 353 stretches or contracts, the energy storage telescopic rod 3532 can stretch or contract accordingly.

[0070] The isolated transmission device includes an isolated transmission crank arm 36. The isolated transmission crank arm 36 is rotatably connected to the isolated output shaft 33. An isolated sliding groove 361 is fixedly arranged on the side of the isolated transmission crank arm 36. The isolated transmission pin 3511 slides along the sliding groove 361. Isolated limiting ends for restricting the isolated transmission pin 3511 are fixedly arranged at both ends of the sliding groove 361. As Figure 12 shown, the isolated limiting ends are respectively set as a first isolated limiting end 3611 and a second isolated limiting end 3612. An isolated transmission rod 362 is also fixedly arranged on the isolated transmission crank arm 36. An isolated arc groove 3121 is fixedly arranged on the second mechanism plate 312. The two ends of the isolated arc groove 3121 are set as a first isolated arc groove end 31211 and a second isolated arc groove end 31212. The isolated transmission rod 362 is inserted into the isolated arc groove 3121 and slides along the isolated arc groove 3121. The isolated transmission rod 362 is linked with the cam disc 32. When the three-position switch 2 performs a closing operation, the isolated transmission rod 362 slides from the second isolated arc groove end 31212 to the first isolated arc groove end 31211. When the three-position switch 2 performs a tripping operation, the isolated transmission rod 362 slides from the first isolated arc groove end 31211 to the second isolated arc groove end 31212.

[0071] The grounded transmission device includes a grounded transmission crank arm 37. The grounded transmission crank arm 37 is rotatably connected to the grounded output shaft 34. A grounded sliding groove 371 is fixedly arranged on the grounded transmission crank arm 37. The grounded transmission pin 3521 slides along the grounded sliding groove 371. Grounded limiting ends for restricting the grounded transmission pin 3521 are fixedly arranged at both ends of the grounded sliding groove 371. As Figure 13As shown, the grounding limiting ends are respectively set as the first grounding limiting end 3711 and the second grounding limiting end 3712; a grounding driving lever 372 is also fixedly arranged on the grounding driving lever 37, and a grounding arc groove 3122 is fixedly arranged on the second mechanism plate 312. The two ends of the grounding arc groove 3122 are set as the first grounding arc groove end 31221 and the second grounding arc groove end 31222. The grounding driving lever 372 is inserted into the grounding arc groove 3122 and slides along the grounding arc groove 3122. The grounding driving lever 372 is linked with the cam disc 32. When the three-position switch 2 performs a grounding operation, the grounding driving lever 372 slides from the first grounding arc groove end 31221 to the second grounding arc groove end 31222.

[0072] The cam disc 32 is arranged in a plate-like structure, including a cam disc mounting hole 321. The central axis of the cam disc mounting hole 321 is collinear with the central axis of the insulating main shaft 22. The insulating main shaft 22 and the cam disc 32 are connected by a connecting shaft 26. Specifically, one end of the connecting shaft 26 is located in the gas-filled compartment 111, and a first connecting hole 261 is fixedly arranged thereon. The cross-section of the first connecting hole 261 is set as a polygon, preferably a hexagon, which matches the cross-section of the insulating main shaft 22. The insulating main shaft 22 is inserted into the first connecting hole 261 and fixedly connected, which can prevent the insulating main shaft 22 from rotating relative to the connecting shaft 26. The other end of the connecting shaft 26 is located in the mechanism chamber 131, and its outer cross-section is set as a polygon, preferably a square, which matches the cross-section of the cam disc mounting hole 321. The other end of the connecting shaft 26 is inserted into the cam disc mounting hole 321 and fixedly connected, which can prevent the cam disc 32 from rotating relative to the connecting shaft 26. A second connecting hole 262 is fixedly arranged at the other end of the connecting shaft 26; the dynamic seal 25 is sleeved outside the connecting shaft 26 and is hermetically connected to the three-position bracket 21 and the partition of the mechanism chamber 131 through the dynamic seal 25.

[0073] A moving arc groove is also arranged on the cam disc 32. The moving arc groove includes an isolation limiting arc groove 322 and a grounding limiting arc groove 323. The isolation limiting arc groove 322 and the grounding limiting arc groove 323 are communicated. The isolation driving lever 362 is inserted into the isolation limiting arc groove 322 and slides along the isolation limiting arc groove 322. The grounding driving lever 372 is inserted into the grounding limiting arc groove 323 and slides along the grounding limiting arc groove 323.

[0074] The two ends of the isolation limiting arc groove 322 are set as the first isolation limiting end 3221 and the second isolation limiting end 3222. The two ends of the grounding limiting arc groove 323 are set as the first grounding limiting end 3231 and the second grounding limiting end 3232. The second isolation limiting end 3222 and the first grounding limiting end 3231 are located at the junction position of the isolation limiting arc groove 322 and the grounding limiting arc groove 323. There is an upward convex part at the junction position, and the convex part is used to prevent the isolation driving lever 362 from sliding into the grounding limiting arc groove 323 and to prevent the grounding driving lever 372 from sliding into the isolation limiting arc groove 322.

[0075] When the three-position switch 2 is in the isolated state, the isolation drive rod 362 is located at the end 31212 of the second isolation arc groove and the second isolation limiting end 3222, and the grounding drive rod 372 is located at the first grounding limiting end 3231. When the three-position switch 2 performs a closing operation, the isolation drive crank 36 drives the isolation drive rod 362 to slide from the end 31212 of the second isolation arc groove to the end 31211 of the first isolation arc groove. During this process, the isolation drive rod 362 moves upward in the vertical direction, so that the isolation drive rod 362 slides from the second isolation limiting end 3222 to the first isolation limiting end 3221, thereby driving the cam disk 32 to rotate along the insulating main shaft 22 and outputting a closing torque to the insulating main shaft. During this process, the grounding drive rod 372 slides along the grounding limiting arc groove 323, and the arc of the grounding limiting arc groove 323 matches the path of the isolation drive rod 362 driving the cam disk 32 to rotate, so that when the cam disk 32 performs a closing operation, it will not affect the grounding drive rod 372. The end of the grounding limiting arc groove 323 is set as the limiting end 3232. When the cam disk 32 is in the closing state, the grounding drive rod 372 moves into the limiting end 3232.

[0076] When the three-position switch 2 performs a grounding operation, the grounding drive crank 37 drives the grounding drive rod 372 to slide from the end 31221 of the first grounding arc groove to the end 31222 of the second grounding arc groove. The arc of the isolation limiting arc groove 322 matches the path of the grounding drive rod 372 driving the cam disk 32 to rotate, so that when the cam disk 32 performs a grounding operation, it will not affect the isolation drive rod 362. The grounding drive rod 372 drives the cam disk 32 to rotate along the insulating main shaft 22 and outputs a grounding torque to the insulating main shaft 22.

[0077] To ensure safety, the closing or grounding operation can only be performed when the three-position switch 2 is in the isolated state. As Figure 9 shown, the three-position switch 2 is in the isolated state. At this time, the isolation drive pin 3511 is located at the second limiting end 3612. When the three-position switch 2 performs a closing operation, when an external force drives the isolation output shaft 33 to rotate, the isolation output shaft 33 drives the isolation energy storage crank 351 to rotate. The isolation energy storage crank 351 drives the isolation drive pin 3511 to slide along the isolation chute 361, and then drives the energy storage compression spring 353 to store energy. When it rotates to make the energy storage compression spring 353 reach the maximum energy storage position, the external force is removed. The isolation output device will continue to rotate under the action of inertia and make the energy storage compression spring 353 rotate past the maximum energy storage position, release the energy storage and drive the isolation drive crank 36 to rotate through the isolation drive pin 3511, so that the isolation drive rod 362 drives the cam disk 32 to rotate and outputs a closing torque to the insulating main shaft 22 through the cam disk 32.

[0078] When the energy storage compression spring 353 reaches the maximum energy storage position, the isolation transmission pin 3511 slides from the second limiting end 3612 along the slide groove 361 to the first limiting end 3611. During this process, the isolation transmission crank arm 36 does not rotate. When the energy storage compression spring 353 releases the stored energy, the isolation transmission pin 3511 drives the isolation transmission crank arm 36 to rotate through the first limiting end 3611, and then the isolation transmission rod 362 drives the cam plate 32 to rotate, and the closing torque is output to the insulating main shaft 22 through the cam plate 32; when the three-position switch 2 needs to be opened, the operation is reversed, and the opening torque is output to the insulating main shaft 22 through the cam plate 32.

[0079] The three-position switch 2 is in an isolated state, at which time the grounding transmission pin 3521 is located at the first grounding limiting end 3711. When the three-position switch 2 is grounded, when the external force drives the grounding output shaft 34 to rotate, the grounding output shaft 34 drives the grounding energy storage arm 352 to rotate, and the grounding energy storage arm 352 drives the grounding transmission pin 3521 to slide along the grounding slide groove 371, thereby driving the energy storage compression spring 353 to store energy. When the energy storage compression spring 353 is rotated to reach the maximum energy storage position, the external force is removed, and the grounding output device will continue to rotate under the action of inertia and make the energy storage compression spring 353 rotate past the maximum energy storage position, release the stored energy, and drive the grounding transmission crank arm 37 to rotate through the grounding transmission pin 3521, so that the grounding transmission rod 372 drives the cam plate 32 to rotate, and outputs the grounding torque to the insulating main shaft 22 through the cam plate 32.

[0080] When the energy storage compression spring 353 reaches the maximum energy storage position, the grounding transmission pin 3521 slides from the first grounding limiting end 3711 along the grounding slide groove 371 to the second grounding limiting end 3712. During this process, the grounding transmission crank arm 37 does not rotate. When the energy storage compression spring 353 releases the stored energy, the grounding transmission pin 3521 drives the grounding transmission crank arm 37 to rotate through the second grounding limiting end 3712, and then the grounding transmission rod 372 drives the cam plate 32 to rotate, and outputs the grounding torque to the insulating main shaft 22 through the cam plate 32.

[0081] This embodiment outputs the opening and closing torque and the grounding torque to the insulating main shaft 22 by driving the cam plate 32 to rotate through the isolation transmission device and the grounding transmission device. It has a simple structure, convenient operation and high transmission efficiency.

[0082] The three-station mechanism 3 also includes a three-station mechanism interlocking plate 38, on which a lower cover plate 381, an upper cover plate 382 and a toggle plate 383 are fixedly provided. The toggle plate 383 is toggled by external force to control the three-station mechanism interlocking plate 38 to move up or down. When the three-station mechanism interlocking plate 38 moves up, the upper cover plate 382 covers the isolation cam sleeve 331. When the three-station mechanism interlocking plate 38 moves down, the lower cover plate 381 covers the grounding cam sleeve 341, to ensure that the isolation output shaft 33 and the grounding output shaft 34 are not operated at the same time.

[0083] The three-position mechanism 3 further includes an interlock device for isolating the output device and the grounding output device.

[0084] The interlock device includes a hanging plate 391, on which an adjusting waist-shaped hole 392 is fixedly provided. An interlock post 3111 is fixedly provided on the first mechanism plate 311. The interlock post 3111 is inserted into the adjusting waist-shaped hole 392, thereby hanging the hanging plate 391 on the first mechanism plate 311. Isolation interlock holes 394 for locking the isolation output shaft 33 and grounding interlock holes 395 for locking the grounding output shaft 34 are respectively provided at both ends of the hanging plate 391. Notches are provided on the isolation interlock holes 394 and the grounding interlock holes 395. Cuts matching the notches of the isolation interlock holes 394 and the grounding interlock holes 395 are respectively provided on the isolation output shaft 33 and the grounding output shaft 34. During the interlock process of this embodiment, when the three-position switch 2 is in the isolation state, the cuts of the isolation output shaft 33 and the grounding output shaft 34 are opposite to the notches of the isolation interlock holes 394 and the grounding interlock holes 395. At this time, the hanging plate 391 is in an unlocked state with the isolation output device and the grounding output device, and the hanging plate 391 can move up and down within the range defined by the adjusting waist-shaped hole 392 to realize the closing or grounding operation of the three-position switch. When the three-position switch is in the closing state, the arc surface of the isolation output shaft 33 abuts against the notch of the isolation interlock hole 394, and the cut of the grounding output shaft 34 is opposite to the notch of the grounding interlock hole 395 and is limited. At this time, the grounding output shaft 34 cannot be operated. When the grounding output device is in the grounding state, the arc surface of the grounding output shaft 34 abuts against the notch of the grounding interlock hole 395, and the cut of the isolation output shaft 33 is opposite to the notch of the isolation interlock hole 394 and is limited. Thus, it is realized that only when both the isolation output device and the grounding output device are in the isolation state can the three-position switch be grounded or closed.

[0085] The three-position mechanism 3 can be independently applied to the existing ring main unit.

[0086] As Figure 14 shown, an indicating device 9 is used to display the state of the three-position switch 2. The indicating device 9 includes an indicating main shaft 91 and an indicating plate 92. The indicating main shaft 91 is connected to the insulating main shaft 22 of the three-position switch 2, and the indicating plate 92 is connected to the indicating main shaft 91 for displaying the state of the three-position switch 2.

[0087] It further includes a connecting device for connecting the indicating device 9 and the insulating main shaft 22. The connecting device includes a connecting shaft 26. A second connecting hole 262 is fixedly provided at one end of the connecting shaft 26. The indicating main shaft 91 is inserted into the second connecting hole 262 and fixedly connected. A first connecting hole 261 is fixedly provided at the other end of the connecting shaft 26. The insulating main shaft 22 is inserted into the first connecting hole 261 and fixedly connected.

[0088] The connecting shaft 26 is sleeved with a dynamic seal 25, and through the dynamic seal 25, the connecting shaft 26 is hermetically connected to the three-position support 21 and the partition of the mechanism chamber 131.

[0089] The indicating device 9 of this embodiment is connected to the insulating main shaft 22. The state of the three-position switch 2 is directly output to the indicating device 9 through the insulating main shaft 22 and is displayed by the indicator board 92, eliminating the intermediate transmission components and improving the indicating efficiency of the state of the three-position switch 2.

[0090] The indicating device 9 can be separately applied to the existing ring main unit.

[0091] As Figure 15 - 18 shown, the main circuit 4 of the circuit breaker includes a main circuit frame 41 of the circuit breaker. The main circuit frame 41 of the circuit breaker is installed with an arc extinguishing chamber assembly 42 and a main circuit power assembly 43. The arc extinguishing chamber assembly 42 includes an arc extinguishing contact seat 8. The arc extinguishing contact seat 8 includes an integrally formed arc extinguishing contact seat column member 81 and an arc extinguishing contact seat surface member 82. The main circuit power assembly 43 includes a support shielding ring 434. The arc extinguishing contact seat 8 and the support shielding ring 434 are used to evenly distribute the electric field around.

[0092] The main circuit frame 41 of the circuit breaker includes two groups of main circuit support plates 411 of the circuit breaker. Generally, the two groups of main circuit support plates 411 are arranged in parallel. An arc extinguishing chamber support plate 412 and an epoxy support plate 413 are fixedly arranged between the two groups of main circuit support plates 411. There are three groups of arc extinguishing chamber support plates 412 and epoxy support plates 413 respectively, and the three groups of arc extinguishing chamber support plates 412 and epoxy support plates 413 are horizontally distributed. The arc extinguishing chamber support plate 412 is located above the epoxy support plate 413. Shaft mounting plates 414 are fixedly arranged on the two groups of main circuit support plates 411; the arc extinguishing chamber assembly 42 includes a vacuum bulb 421 and an arc extinguishing contact seat 8. The arc extinguishing contact seat 8 is fixedly connected to the vacuum bulb 421. The arc extinguishing contact seat 8 and the arc extinguishing chamber support plate 412 are fixedly connected through a first fixing member 415. The epoxy support plate 413 is connected to the vacuum bulb 421 for supporting the vacuum bulb 421.

[0093] The arc extinguishing contact seat 8 includes an arc extinguishing contact seat column member 81 and an arc extinguishing contact seat surface member 82. The arc extinguishing contact seat column member 81 is vertically installed on one side of the arc extinguishing contact seat surface member 82. The arc extinguishing contact seat column member 81 and the arc extinguishing contact seat surface member 82 are integrally designed to eliminate the potential trouble of partial discharge caused by assembly. The structure of the arc extinguishing contact seat 8 in this embodiment replaces the existing copper bar bending. Through symmetric design, it is ensured that the installation of the isolating knife 235 and the vacuum bulb 421 are on the same horizontal plane, so as to ensure the rationality of the phase-to-phase (longitudinal) insulation clearance distribution of the main circuit 4 of the circuit breaker. On the other side of the arc extinguishing contact seat surface member 82, an arc extinguishing contact seat hole 83 is fixedly arranged. The arc extinguishing contact seat hole 83 is opposite to the support plate mounting hole on the arc extinguishing chamber support plate 412. The first fixing member 415 is inserted into the arc extinguishing contact seat hole 83 and the support plate mounting hole to realize the fixed connection between the arc extinguishing contact seat 8 and the arc extinguishing chamber support plate 412.

[0094] In this embodiment, the arc extinguishing contact seat member 81 has a columnar structure. A flat arc extinguishing plate 84 is fixedly arranged at the upper end of the arc extinguishing contact seat member 81. The thickness of the arc extinguishing plate 84 is less than the diameter of the arc extinguishing contact seat member 81. An inclined surface 845 is provided at the junction of the arc extinguishing contact seat member 81 and the arc extinguishing plate 84, and smooth connection is achieved through the inclined surface 845. The arc extinguishing contact seat member 81 and the arc extinguishing plate 84 are integrally designed to eliminate the potential risk of partial discharge caused by assembly. A concave groove 841 is fixedly arranged on the arc extinguishing plate 84. The arc extinguishing plate 84 is connected to the isolating knife 235. The groove 841 is matched with the second contact point 2354 of the isolating knife 235. The second contact point 2354 is snapped into the groove 841, which is convenient for the positioning of the installation of the two and the relative rotation of the isolating knife 235 and the arc extinguishing contact seat 8.

[0095] The main circuit power component 43 includes an insulating main shaft 431. Three pressure maintaining brackets 433 are rotatably arranged on the insulating main shaft 431. A bracket shielding ring 434 is arranged outside one group of breaker main circuit support plates 411. The bracket shielding ring 434 is fixedly connected to the pressure maintaining bracket 433. A branch busbar 437 is arranged outside another group of breaker main circuit support plates 411. The branch busbar 437 is fixedly connected to the pressure maintaining bracket 433. The branch busbar 437 is fixedly connected to the branch busbar assembly 44. A stepped shielding ring mounting hole 4341 is fixedly arranged on the bracket shielding ring 434. First mounting holes corresponding to the shielding ring mounting hole 4341 are fixedly arranged on the breaker main circuit support plate 411 and the pressure maintaining bracket 433. A second fixing member is sequentially inserted into the shielding ring mounting hole 4341 and the first mounting hole, and the bracket shielding ring 434, the breaker main circuit support plate 411, the pressure maintaining bracket 433 are fixedly connected. The second fixing member is arranged inside the bracket shielding ring 434 through the shielding ring mounting hole 4341 to uniformly distribute the electric field around the second fixing member, thereby ensuring the insulation requirement of the second fixing member for the side shell of the gas tank 11.

[0096] A number of pressure maintaining cams 432 are rotatably arranged on the insulating main shaft 431. Two groups of pressure maintaining cams 432 correspond to one group of pressure maintaining brackets 433. In this embodiment, the two groups of pressure maintaining cams 432 are respectively located on both sides of the pressure maintaining bracket 433. An arc-shaped groove 4321 is fixedly arranged on the pressure maintaining cam 432.

[0097] The vacuum cell 421 is linked with a double-headed screw rod 439. The double-headed screw rod 439 is provided with opposite threads, that is, one end is set as a right-handed thread and the other end is set as a left-handed thread, so as to realize the functions of adjusting the opening distance and over-travel of the vacuum cell 421, and solve the problem that when both ends are conventional threads, the opening distance cannot be adjusted and only the over-travel can be adjusted. In this embodiment, the double-headed screw rod 439 adopts a fine-thread screw, which solves the problem that the coarse-thread screw cannot accurately adjust the opening distance. At the same time, because the fine-thread screw has better self-locking performance, it can improve the mechanical stability of the main circuit 4 of the circuit breaker. The double-headed screw rod 439 is fixedly provided with a flexible connection 438, and the flexible connection 438 is fixedly connected with the branch busbar 437.

[0098] The double-headed screw rod 439 is helically connected with a vacuum switch pull rod 435. The lower end of the vacuum switch pull rod 435 is provided with a pressure-holding cap sleeve. A pulley slidingly connected with the arc-shaped groove 4321 is arranged on the pressure-holding cap sleeve. A pressure-holding spring 436 is arranged between the vacuum switch pull rod 435 and the pressure-holding cap sleeve.

[0099] During the implementation of the main circuit 4 of the circuit breaker, when the circuit breaker mechanism 5 performs a closing or opening operation, it drives the insulating main shaft 431 to rotate. The rotation of the insulating main shaft 431 drives the double-headed screw rod 439 to move up and down, thereby controlling the main circuit 4 of the circuit breaker to be in the closing or opening state.

[0100] The bracket shielding ring 434, the branch busbar 437 and the arc-extinguishing contact seat 8 are designed with rounded corners, without edges and corners, so that the parts themselves ensure a uniform electric field when they are energized, achieving the purpose of improving the insulation performance of the main circuit 4 of the circuit breaker.

[0101] The main circuit 4 of the circuit breaker can move independently into the existing ring main unit.

[0102] As Figure 19 - 21 shown, the interlocking device 6 includes a circuit breaker interlocking plate 61 and a three-position interlocking plate 62. The three-position interlocking plate 62 is connected with the three-position mechanism 3. The circuit breaker mechanism 5 controls the circuit breaker interlocking plate 61 through a snap device to restrict the movement of the three-position interlocking plate 62.

[0103] The interlocking device 6 is fixedly connected with the circuit breaker mechanism 5 or / and the three-position mechanism 3 through an interlocking fixing plate 63. The circuit breaker interlocking plate 61 is fixedly provided with a first interlocking hole 611 and a second interlocking hole 612. A sliding rod 613 is fixedly arranged on the circuit breaker frame of the circuit breaker mechanism 5. The sliding rod 613 is located in the second interlocking hole 612 and slides along the second interlocking hole 612. The circuit breaker mechanism 5 includes a energy storage operation handle 52, and the energy storage operation handle 52 passes through the first interlocking hole 611.

[0104] The three-position interlock plate 62 is rotatably connected to the interlock fixing plate 63. At both ends of the three-position interlock plate 62, there are fixedly provided interlock waist-shaped holes 621. The breaker interlock plate 61 is rotatably connected to the three-position interlock plate 62, and the three-position interlock plate 62 is rotatably connected to the three-position mechanism interlock plate 38 through fastening rotating parts.

[0105] The interlock device 6 further includes an interlock return mechanism 64. The interlock return mechanism 64 includes a first interlock rod 641, a second interlock rod 642, a third interlock rod 643, and a return spring 644. The first interlock rod 641 and the second interlock rod 642 are fixedly provided on the interlock fixing plate 63. The third interlock rod 643 is fixedly provided on the breaker interlock plate 61. The return spring 644 is sleeved on the first interlock rod 641. Two spring output ends 645 of the return spring 644 are located on both sides of the second interlock rod 642 and the third interlock rod 643. When the three-position mechanism interlock plate 38 moves downward, the third interlock rod 643 drives the upper spring output end 645 to move upward, and the second interlock rod 642 is used to limit the lower spring output end 645. When the three-position mechanism interlock plate 38 moves upward, the third interlock rod 643 drives the lower spring output end 645 to move downward, and the second interlock rod 642 is used to limit the upper spring output end 645. After the corresponding operation is completed, the breaker interlock plate 61 is controlled by the return spring 644 to return to the initial state.

[0106] The buckle device includes a first buckle plate 651 and a second buckle plate 652. The first buckle plate 651 and the second buckle plate 652 are fixedly provided on the breaker interlock plate 61, and the first buckle plate 651 is located above the second buckle plate 652. The breaker mechanism 5 includes a breaker indication component. The breaker indication component is linked with the breaker operation component to display the state of the breaker main circuit 4. The breaker indication component includes a breaker indication main shaft 51 and a breaker indication board 53. The indication main shaft 51 is linked with the breaker operation component. The state of the breaker operation component controls the rotation direction of the breaker indication main shaft 51, and then different states of the breaker main circuit 4 are displayed through different rotation directions of the breaker indication board 53.

[0107] The breaker indicating main shaft 51 is provided with a snap notch 511. When the main circuit 4 of the breaker is in the closed state, the breaker indicating main shaft 51 rotates to make the breaker indicating main shaft 51 snap into the space between the first buckle plate 651 and the second buckle plate 652, locking the breaker interlock plate 61. At this time, the three-position interlock plate 38 cannot be moved through the three-position interlock plate 62, and both the isolation output shaft 33 and the grounding output shaft 34 are in a state covered by the three-position mechanism interlock plate 38. When the main circuit 4 of the breaker is tripped, the breaker indicating main shaft 51 rotates to make the snap notch 511 disengage from the interference state with the first buckle plate 651 and the second buckle plate 652, unlocking the breaker interlock plate 61. At this time, operating the three-position mechanism interlock plate 38 to move up or down to operate the three-position mechanism 3, so as to achieve the purpose of being unable to operate the three-position mechanism 3 when the main circuit 3 of the breaker is in the closed state, ensuring the safety of operation.

[0108] The interlock device 6 can be independently applied to the existing ring main unit.

[0109] Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

Claims

1. An environmentally friendly gas-insulated ring main unit, characterized in that: It includes a cabinet body, a three-position switch, a three-position mechanism, a breaker main circuit and a breaker mechanism. The three-position switch, the three-position mechanism, the breaker main circuit and the breaker mechanism are installed in the cabinet body. An interlock device is connected between the three-position mechanism and the breaker mechanism to prevent the three-position mechanism from being operated under live conditions. The three-position switch includes an insulating main shaft, and the indicating device includes an indicating main shaft. The insulating main shaft is connected to the indicating main shaft. The three-position switch includes a three-position bracket, an insulating main shaft and a closing and opening mechanism. The closing and opening mechanism includes three-phase upper insulators, three-phase lower insulators and a transmission assembly. The three-phase upper insulators are fixedly arranged on the three-position bracket, and a closing and grounding contact seat is fixedly arranged on the busbar. The three-phase lower insulators are fixedly arranged on the three-position bracket, and a transition row is fixedly arranged on the three-phase lower insulators. An arc extinguishing chamber contact seat is fixedly arranged on the transition row. The transmission assembly includes a connecting rod structure, and the connecting rod structure includes a transmission crank arm, a moving knife pull rod and a moving knife pull plate. The transmission crank arm is fixedly arranged on the insulating main shaft. There are two groups of moving knife pull rods, which are symmetrically arranged. The two ends of the moving knife pull rod are respectively rotationally connected to the transmission crank arm and the moving knife pull plate. Nylon pins are fixedly arranged on the insulating main shaft on both sides of the transmission crank arm to limit the movement of the transmission crank arm.

2. The environmentally friendly gas-insulated ring main unit according to claim 1, characterized in that: The cabinet body includes an air tank, an instrument room and a cabinet frame. An operating mechanism room and a cable room are arranged in the cabinet frame. An inflatable compartment is arranged in the air tank. The breaker mechanism and the three-position mechanism are installed in the operating mechanism room. The three-position switch and the breaker main circuit are installed in the inflatable compartment. The breaker mechanism is connected to the breaker main circuit, and the three-position switch is connected to the three-position mechanism.

3. The environmentally friendly gas-insulated ring main unit according to claim 1, characterized in that: The insulating main shaft and the closing and opening mechanism are installed on the three-position bracket. The insulating main shaft is linked with the closing and opening mechanism. The closing and opening mechanism includes a shielding ring and a shielding cover, which are used for controlling temperature rise and uniforming the electric field.

4. The environmentally friendly gas-insulated ring main unit according to claim 1, characterized in that: The three-position mechanism includes a three-position frame and a cam disc. The cam disc is fixedly arranged on the insulating main shaft of the three-position switch. An isolating output device, an isolating transmission device, a grounding output device, a grounding transmission device and an energy storage device are installed on the three-position frame. The isolating transmission device and the grounding transmission device are linked with the cam disc and respectively output closing and opening torque and grounding torque to the insulating main shaft through the cam disc.

5. The environmentally friendly gas-insulated ring main unit according to claim 1, characterized in that: The breaker main circuit includes a breaker main circuit frame. An arc extinguishing chamber assembly and a main circuit power assembly are installed on the breaker main circuit frame. The arc extinguishing chamber assembly includes an arc extinguishing contact seat, and the arc extinguishing contact seat includes an integrally formed arc extinguishing contact seat column part and an arc extinguishing contact seat surface part. The main circuit power assembly includes a bracket shielding ring. The arc extinguishing contact seat and the bracket shielding ring are used for uniforming the electric field around.

6. The environmentally friendly gas-insulated ring main unit according to claim 1, characterized in that: The interlock device includes a breaker interlock plate and a three-position interlock plate. The three-position interlock plate is connected to the three-position mechanism. The breaker mechanism controls the breaker interlock plate through a buckle device to limit the movement of the three-position interlock plate.

7. The environmentally friendly gas-insulated ring main unit according to claim 1, characterized in that: The indicating device includes an indicating plate. The indicating main shaft is connected to the indicating plate, and the indicating plate is used for displaying the state of the three-position switch.

8. The environmentally friendly gas-insulated ring main unit according to claim 1, characterized in that: The transmission assembly further includes isolation knives. There are two groups of isolation knives, which are arranged in parallel and fixedly connected through a first knife support and a second knife support. A connecting rod located between the first knife support and the second knife support is also fixedly installed on the two groups of isolation knives. The connecting rod is rotatably connected to the moving knife pull plate. On the isolation knife, a first contact point located at the knife head and a second contact point located at the knife tail are fixedly installed. The second contact point contacts or separates from the arc extinguishing chamber contact seat.

9. The environmentally friendly gas-insulated ring main unit according to claim 5, characterized in that: The arc extinguishing contact seat column is vertically installed on the arc extinguishing contact seat surface member. The arc extinguishing contact seat surface member is provided with an arc extinguishing contact seat hole, and the arc extinguishing contact seat hole is opposite to the support plate installation hole on the arc extinguishing chamber support plate. A first fixing member is inserted into the arc extinguishing contact seat hole and the support plate installation hole to fixedly connect the arc extinguishing contact seat and the arc extinguishing chamber support plate.

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