Miniaturized 40.5 kV ring main unit gas tank and ring main unit thereof

Abstract

The invention belongs to the technical field of switch equipment, and particularly relates to a miniature 40.5 kV ring main unit gas tank and a ring main unit thereof, a switch assembly and a mounting frame are arranged in the gas tank, the miniature 40.5 kV ring main unit gas tank is characterized in that the switch assembly comprises a circuit breaker and a three-position switch, the circuit breaker comprises a movable contact seat, a solid-sealed polar pole and a closing and opening transmission mechanism, and the three-position switch is arranged on the mounting frame. The movable contact seat is fixed at the top of the solid-sealed polar pole, the solid-sealed polar pole, the closing and opening transmission mechanism and the three-position switch are all arranged on the mounting frame, the closing and opening transmission mechanism is located at the side part of the solid-sealed polar pole, a transmission block arranged on the movable contact seat is connected with the movable end of an arc extinguish chamber of the solid-sealed polar pole, and the transmission block is in transmission connection with the closing and opening transmission mechanism. And the isolation contact at the bottom of the solid-sealed polar pole is separated from or conducted with the three-position switch. According to the invention, the overall height of the gas tank unit is reduced, the electric field can be homogenized while the electrical conduction is ensured, the interphase creepage risk does not exist, and the insulation performance is excellent.

Description

Technical Field

[0001] The present invention specifically relates to a miniaturized 40.5kV ring main unit gas box and a ring main unit thereof, belonging to the technical field of switchgear. Background Art

[0002] China is vigorously developing new energy. Inland and offshore wind power mostly adopts 40.5kV ring network. The ring network cabinet is installed inside the wind turbine tower. Due to the limited space inside the wind turbine tower, the ring network cabinet is required to be miniaturized.

[0003] The energy storage industry has experienced rapid growth in recent years, with numerous energy storage power station projects both domestically and internationally requiring a large number of 40.5kV ring main unit (RMU) units. Energy storage power stations, often utilizing containerized integrated layouts, offer increasing energy density and shrinking footprints. This limited integration size necessitates an increasing demand for miniaturized RMU units.

[0004] Chinese patent document CN 115000866 A discloses a ring main unit (RMU) comprising a gas box, a fixed frame secured to the inner wall of the gas box, and a circuit breaker located within the gas box. The circuit breaker comprises a circuit breaker body. The circuit breaker body comprises an insulating housing and first and second ends located at either end of the insulating housing. The first end is provided with a first fixing seat, and the second end is provided with a second fixing seat. Both the first and second fixing seats are metal components and enclose a shielded space to enclose the conductive members disposed on the first and second ends. The first fixing seat is secured to the fixed frame via an insulator, and the second fixing seat is secured to the fixed frame via another insulator. However, this technical solution still has drawbacks. The arc extinguishing chamber support is fixed close to the static end insulator, resulting in weak strength. The static contact seat, arc extinguishing chamber, and moving contact seat make the pole height high, which does not meet the requirements of miniaturization.

[0005] Chinese patent document CN218975340U, "A Novel Vacuum Switch for 35kV Ring Main Units," discloses a novel vacuum switch for 35kV ring main units. This relates to circuit breaker technology and includes a switch frame with upper and lower insulating beams fixed to the top and bottom of the switch frame. A drive shaft is mounted near the bottom of the switch frame, with three sets of crank arms sleeved onto the surface of the drive shaft. A vacuum switch mechanism is positioned horizontally within the switch frame, perpendicular to the drive shaft. The entire switch is housed within a cylindrical pole sleeve. This assembly method offers a simple and clear structure, making production and installation easy and efficient. The modular design of the components allows for commonality across upper and lower isolation and independent PT cabinet switches, enabling centralized mass production, low cost, a limited number of parts, and stable and controllable quality. Metal inserts are added to non-metallic parts to extend their lifespan. The extensive use of environmentally friendly non-metallic materials results in an overall environmentally friendly design and a low switching electric field. The vacuum interrupter of this device is arranged horizontally, but due to the size limitations of the 35kV vacuum interrupter and the layout of the transmission components, the width of the cabinet cannot be miniaturized. The disconnector adopts an integrated insulating main shaft structure, and there is a creepage path between phases, which poses a serious risk of phase-to-phase insulation. Summary of the Invention

[0006] The purpose of the present invention is to provide a miniaturized 40.5kV ring main unit gas box and its ring main unit, which not only enhances the structural strength and reduces the overall height of the gas box unit, but also can shield the sharp corners and burrs in the high-voltage structure while ensuring electrical conduction, uniform electric field, and no phase-to-phase creepage risk, so that the insulation performance is excellent.

[0007] In order to achieve the above object, the first technical solution of the present invention is: a miniaturized 40.5kV ring main unit gas box, comprising a gas box body, the interior of the gas box body is filled with insulating gas, and is provided with a switch assembly and a mounting frame. The connection terminal at the top of the switch assembly serves as the busbar connection terminal, and the outlet terminal at the bottom serves as the cable connection terminal. Its innovation lies in: The switch assembly includes a circuit breaker and a three-position switch. The circuit breaker has three-phase units A, B, and C with the same structure and arranged vertically separately. Each phase unit includes a moving contact seat, a sealed pole, and a closing and opening transmission mechanism. The moving contact seat is fixed to the top of the sealed pole. The sealed pole is provided on one side of the mounting frame and is detachably connected thereto. The closing and opening transmission mechanism and the three-position switch are both provided on the mounting frame, and the closing and opening transmission mechanism is located between the sealed pole and the mounting frame. The three-position switch is located below the sealed pole. The moving contact seat is provided with a transmission block that slides with it, and the transmission block is fixedly connected to the moving end of the arc extinguishing chamber at the top of the sealed pole. The transmission block is connected to the closing and opening transmission mechanism, and the isolating contact provided at the bottom of the sealed pole is separated or connected with the three-position switch.

[0008] In the above-mentioned first technical solution, a top expansion sleeve is provided on the upper part of the gas box body, and a connecting busbar for electrical connection is also provided on the dynamic contact seat, and the connecting busbar is electrically connected to the connector at the bottom of the top expansion sleeve. A wire outlet sleeve is provided on the lower side of the gas box body, and the three-position switch is connected by connecting the copper rod and the connector on the side of the wire outlet sleeve.

[0009] In the above-mentioned first technical solution, the closing and opening transmission mechanism includes a transmission plate, an insulating pull rod and a circuit breaker crank arm. The circuit breaker crank arm is rotatably connected to the mounting frame and rotates around the circuit breaker crank arm axis hole of the mounting frame. The transmission plate is rotatably connected to the moving contact seat. The two ends of the insulating pull rod are respectively rotatably connected to the transmission plate and the circuit breaker crank arm. A guide groove is provided on the moving contact seat. The transmission block is connected to the transmission plate and slides along the guide groove under the driving action of the transmission plate.

[0010] In the above-mentioned first technical solution, the insulating pull rod includes an insulating rod, a sliding rod and a spring. The sliding rod is fixed to the insulating rod as a whole, and the insulating rod is rotatably connected to the transmission plate. The spring is mounted on the sliding rod, and the two ends of the spring are respectively against the baffles provided on the sliding rod. At the same time, the sliding rod is also rotatably connected to the circuit breaker arm.

[0011] In the first technical solution described above, the insulating rod is rotatably connected to the transmission plate via a ball bearing screw, and the sliding rod is also rotatably connected to the circuit breaker arm via a pin in a shaft sleeve at its end.

[0012] In the above-mentioned first technical solution, a plurality of coaxially arranged contact finger grooves are provided at the bottom of the moving contact seat, a plurality of spring contact fingers are provided on the periphery of the moving end of the arc extinguishing chamber, and each spring contact finger is arranged in a corresponding contact finger groove. At the same time, the moving end of the arc extinguishing chamber is fixedly connected to the transmission block by a fastening bolt.

[0013] In the first technical solution mentioned above, the sealed pole has a vacuum arc chamber, and the outer periphery of the vacuum arc chamber is coated with epoxy resin. The interior of the vacuum arc chamber is provided with a static contact which is arranged opposite to the moving end of the arc chamber with a gap, and the static contact is fixedly connected to the isolating contact.

[0014] In the first technical solution described above, the bottom of the sealed pole has a positioning groove for forming a positioning fit with the isolation contact.

[0015] In the above-mentioned first technical solution, the three-position switch includes a knife switch, an insulating plate, an insulating connecting rod, a grounding contact, a knife switch arm and a conductive block. The grounding contact is fixed on the mounting frame, the knife switch arm is rotatably connected to the mounting frame, and an insulating connection is formed between the conductive block and the mounting frame. The knife switch is fixedly connected to the insulating plate, and the insulating plate is rotatably connected to the knife switch arm through the insulating connecting rod. One end of the knife switch is rotatably connected to the isolating contact, and the other end forms a conductive and rotatable connection with the conductive block.

[0016] In the above-mentioned first technical solution, the mounting frame has a grounding contact fixing plate, the grounding contact is fixed on the grounding contact fixing plate, and a buffer pad is provided between the grounding contact and the grounding contact fixing plate.

[0017] In the above-mentioned first technical solution, the mounting frame has an insulator fixing plate, and the conductive block is insulatedly connected to the insulator fixing plate via the insulator.

[0018] In the above-mentioned first technical solution, the mounting frame includes side plates and a pole fixing plate fixedly connected to the side plates, and the sealed pole is detachably connected to the pole fixing plate.

[0019] In the first technical solution described above, the pole fixing plate has a diagonal support plate for enhancing structural strength, the diagonal support plate has a circuit breaker crank arm shaft hole, and the circuit breaker crank arm is rotatably connected to the diagonal support plate.

[0020] In the first technical solution described above, the mounting frame has a pole fixing plate, the epoxy resin sealing the back of the pole is connected to the pole fixing plate via a fastener, and the thickness of the epoxy resin sealing the back of the pole is greater than the thickness of the epoxy resin on the remaining outer portion.

[0021] In order to achieve the above-mentioned purpose, the second technical solution of the present invention is: a miniaturized 40.5kV ring main unit, including an instrument room, a mechanism room and a cable room, and the instrument room is located above the mechanism room, and the cable room is located below the mechanism room. Its innovation lies in: it also includes the above-mentioned miniaturized 40.5kV ring main unit gas box, which is arranged on one side of the mechanism room and side by side with it, and the three-position switch is also electrically connected to the cable in the cable room.

[0022] The positive effects of the present invention are as follows: after adopting the miniaturized 40.5kV ring main unit gas box and the ring main unit thereof of the present invention, since the switch assembly in the ring main unit gas box of the present invention includes a circuit breaker and a three-position switch, the circuit breaker has three-phase units A, B, and C with the same structure and arranged vertically separately, each phase unit includes a moving contact seat, a sealed pole and a closing and opening transmission mechanism, the moving contact seat is fixed on the top of the sealed pole, the sealed pole is provided on one side of the mounting frame and is detachably connected thereto, the closing and opening transmission mechanism and the three-position switch are both provided on the mounting frame, and the closing and opening transmission mechanism is located between the sealed pole and the mounting frame, and the three-position switch is located below the sealed pole. The moving contact seat is provided with a transmission block that is slidably matched with it, and the transmission block is fixedly connected to the moving end of the arc extinguishing chamber at the top of the solid-sealed pole. The transmission block is in transmission connection with the closing and opening transmission mechanism. The isolating contact provided at the bottom of the solid-sealed pole is separated from or connected to the three-position switch. The present invention has the advantages that: (1) The present invention adopts a small solid-sealed pole solution, which is integrated with a three-position switch. At the same time, the integrated frame structure is not only compact but also easy to install. Compared with the transmission solid-sealed pole, the height is reduced. The position of the transmission mechanism is changed from the vertical pole direction to the side (back) direction, which also enhances the structural strength and reduces the overall height of the pole. At the same time, the present invention fully utilizes the side space to set the transmission components, achieving miniaturization; (2) The three-phase circuit of the present invention adopts an independent structure, without inter-phase leakage and creepage paths, thus reducing the risk of inter-phase short circuit; (3) The structural method of fixed connection between the movable contact seat and the sealed pole of the present invention not only ensures the electrical conduction function, but also provides transmission support and shielding of sharp corners and burrs in the high-voltage structure, and uniform electric field function. At the same time, it also reduces the number of parts, and the overall structure is compact, which conforms to the miniaturization design concept; To sum up, the present invention is aimed at the 40.5kV ring main unit gas box and the ring main unit with such structure. Not only is the overall structure miniaturized, but the ring main unit gas box also adopts gas-sealed insulation, making the product safer and more reliable. The special miniaturized solid-sealed pole side-mounted solution reduces the overall height. The three-phase circuits of the present invention are independent of each other, there is no risk of phase-to-phase creepage, and the insulation performance is also more superior. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a structural diagram of a specific embodiment of a ring main unit of the present invention; Figure 2 yes Figure 1 A side view schematic diagram of Figure 3 This is a structural diagram of the ring main unit gas box of the present invention when the circuit breaker is in the closed position and the three-position switch is in the closed position; Figure 4 This is a schematic structural diagram of the ring main unit gas box of the present invention when the circuit breaker is in the open position and the three-position switch is in the closed position; Figure 5 This is a schematic diagram of the structure of the ring main unit gas box of the present invention when the circuit breaker is in the open position and the three-position switch is in the isolation position; Figure 6 This is a structural diagram of the ring main unit gas box of the present invention when the circuit breaker is in the open position and the three-position switch is in the connected position; Figure 7 It is a structural schematic diagram of the solid-sealed pole of the present invention; Figure 8 It is a structural schematic diagram of the dynamic contact seat of the present invention; Figure 9 It is a structural schematic diagram of the installation frame of the present invention; Figure 10 It is a structural schematic diagram of the insulating pull rod of the present invention. DETAILED DESCRIPTION

[0024] The present invention will be further described below with reference to the accompanying drawings and given embodiments, but the present invention is not limited thereto.

[0025] Example 1 like Figure 1 、 2 , 3, 4, 5, 6, 7, 8, 9, and 10 show a miniaturized 40.5 kV ring main unit gas box, comprising a gas box body, the interior of the gas box body is filled with insulating gas, and is provided with a switch assembly 5 and a mounting frame 6. The connection terminal at the top of the switch assembly 5 serves as the busbar connection terminal, and the outlet terminal at the bottom serves as the cable connection terminal. The switch assembly 5 includes a circuit breaker and a three-position switch 54. The circuit breaker has three-phase units A, B, and C with the same structure and arranged vertically separately. Each phase unit includes a moving contact seat 51, a sealed pole 52, and a closing and opening transmission mechanism 53. The moving contact seat 51 is fixed to the top of the sealed pole 52. The sealed pole 52 is provided on one side of the mounting frame 6 and is detachably connected thereto. The closing and opening transmission mechanism 53 and the three-position switch 54 are both provided on the mounting frame 6, and the closing and opening transmission mechanism 53 is located between the sealed pole 52 and the mounting frame 6. The three-position switch 54 is located below the sealed pole 52. The moving contact seat 51 is provided with a transmission block 511 that slides with it, and the transmission block 511 is fixedly connected to the moving end 521 of the arc extinguishing chamber at the top of the sealed pole 52. The transmission block 511 is transmission-connected to the closing and opening transmission mechanism 53, and the isolating contact 522 provided at the bottom of the sealed pole 52 is separated or connected with the three-position switch 54.

[0026] Further, such as Figure 1 、2 As shown, in order to ensure reliable electrical connection between the circuit breaker and the busbar and the main body of the ring network cabinet, and to ensure the overall sealing of the interior of the gas box body, a top expansion sleeve 71 is provided on the upper part of the gas box body, and an electrically connected connecting busbar 81 is also provided on the moving contact seat 51, and the connecting busbar 81 is electrically connected to the connector at the bottom of the top expansion sleeve 71. An outlet sleeve 72 is provided on the lower side of the gas box body, and the three-position switch 54 is connected by connecting the copper rod 82 and the connector on the side of the outlet sleeve 72.

[0027] Further, such as Figure 3 、 4 As shown in Figures 5 and 6, in order to ensure the stability of the structural transmission during the closing or opening process of the circuit breaker, and to constrain the up and down movement of the transmission block to achieve the purpose of precise closing or opening, and to ensure that the closing or opening is in place, the closing and opening transmission mechanism 53 includes a transmission plate 531, an insulating pull rod 532 and a circuit breaker crank arm 533. The circuit breaker crank arm 533 is rotatably connected to the mounting frame 6 and rotates around the circuit breaker crank arm shaft hole 61 of the mounting frame 6. The transmission plate 531 is rotatably connected to the moving contact seat 51. The two ends of the insulating pull rod 532 are rotatably connected to the transmission plate 531 and the circuit breaker crank arm 533 respectively. A guide slot 512 is provided on the moving contact seat 51. The transmission block 511 is connected to the transmission plate 531 and slides along the guide slot 512 under the driving action of the transmission plate 531.

[0028] Further, such as Figure 10 As shown, in order to further improve the rationality and compactness of the structure and ensure that the circuit breaker can be accurately closed or opened, the insulating pull rod 532 includes an insulating rod 5321, a sliding rod 5322 and a spring 5323. The sliding rod 5322 is fixed to the insulating rod 5321 as a whole, and the insulating rod 5321 is rotatably connected to the transmission plate 531. The spring 5323 is mounted on the sliding rod 5322, and the two ends of the spring 5323 are respectively against the baffle 5325 provided on the sliding rod 5322. At the same time, the sliding rod 5322 is also rotatably connected to the circuit breaker arm 533.

[0029] Further, such as Figure 10 As shown, to facilitate adjustment of the overall length of the insulating rod, the insulating rod 5321 is rotatably connected to the transmission plate 531 via a ball bearing screw 5324. The sliding rod 5322 is also rotatably connected to the circuit breaker arm 533 via a pin within a sleeve 5326 at its end. Specifically, the threaded fixing position between the ball bearing screw 5324 and the insulating plate 5321 allows adjustment of the overall length of the insulating rod 532. Furthermore, the ball bearing of the ball bearing screw 5324 can also compensate for the threaded fixing angle.

[0030] Further, such as Figure 8As shown, in order to achieve both a soft connection between the movable contact seat and the movable end of the arc extinguishing chamber of the present invention and a more compact structural connection, reduce the overall volume and height, and further improve the miniaturization of the structure, the bottom of the movable contact seat 51 is provided with a plurality of coaxially arranged contact finger grooves 513, and the outer periphery of the movable end 521 of the arc extinguishing chamber is provided with a plurality of spring contact fingers 514, and each spring contact finger 514 is arranged in a corresponding contact finger groove 513. At the same time, the movable end 521 of the arc extinguishing chamber is fixedly connected to the transmission block 511 by a fastening bolt 515.

[0031] Further, such as Figure 3 、 4 As shown in Figures 5 and 6, in order to achieve vacuum arc extinguishing and ensure the insulation of the periphery of the vacuum arc extinguishing chamber, the sealed pole 52 has a vacuum arc extinguishing chamber 523, and the periphery of the vacuum arc extinguishing chamber 523 is coated with epoxy resin 524. The interior of the vacuum arc extinguishing chamber 523 is provided with a static contact that is arranged opposite to the moving end 521 of the arc extinguishing chamber and has a gap, and the static contact is fixedly connected to the isolating contact 522.

[0032] Further, such as Figure 7 As shown, in order to achieve positioning connection between the sealed pole and the isolation contact and ensure assembly accuracy, the bottom of the sealed pole 52 has a positioning groove 525 that forms a positioning match with the isolation contact 522. The positioning groove 525 is a step-shaped positioning groove.

[0033] Further, such as Figure 3 、 4 As shown in Figures 5 and 6, in order to serve as an isolating switch and a grounding switch, the three-position switch 54 includes a knife switch 541, an insulating plate 542, an insulating connecting rod 543, a grounding contact 544, a knife switch arm 545 and a conductive block 546. The grounding contact 544 is fixed on the mounting frame 6, the knife switch arm 545 is rotatably connected to the mounting frame 6, and an insulating connection is formed between the conductive block 546 and the mounting frame 6. The knife switch 541 is fixedly connected to the insulating plate 542, and the insulating plate 542 is rotatably connected to the knife switch arm 545 through the insulating connecting rod 543. One end of the knife switch 541 is rotatably connected to the isolating contact 522, and the other end is conductively and rotatably connected to the conductive block 546.

[0034] Further, such as Figure 3 、 4 As shown in Figures 5 and 6, in order to further improve the rationality of the structure and facilitate quick and easy assembly, making the structure more compact and reasonable, the mounting frame 6 has a grounding contact fixing plate 65, the grounding contact 544 is fixed on the grounding contact fixing plate 65, and a buffer pad 547 is provided between the grounding contact 544 and the grounding contact fixing plate 65, which can effectively buffer and protect the grounding contact 544.

[0035] Further, such as Figure 3 、 4 As shown in Figures 5 and 6, in order to facilitate the installation of the conductive block and ensure the insulation between the conductive block and the mounting frame, the mounting frame 6 has an insulator fixing plate 66, and the conductive block 546 is insulatedly connected to the insulator fixing plate 66 through an insulator 548.

[0036] Further, such as Figure 3 、 4 As shown in Figures 5, 6 and 9, in order to facilitate the installation and fixation of the sealed pole, the installation frame 6 includes a side plate 62 and a pole fixing plate 63 fixedly connected to the side plate 62, and the sealed pole 52 is detachably connected to the pole fixing plate 63.

[0037] Further, such as Figure 3 、 4 As shown in Figures 5, 6 and 9, in order to strengthen the structural strength of the pole fixing plate, the pole fixing plate 63 has a diagonal support plate 64 for strengthening the structural strength. The diagonal support plate 64 has a circuit breaker crank arm shaft hole 61, and the circuit breaker crank arm 533 is rotatably connected to the diagonal support plate 64.

[0038] Further, such as Figure 3 、 4 As shown in Figures 5 and 6, in order to ensure the insulation performance between the sealed pole and the pole fixing plate, and to prevent the fasteners from destroying the vacuum performance of the sealed pole when the sealed pole is connected to the mounting frame, the mounting frame 6 has a pole fixing plate 63, and the epoxy resin 524 on the back of the sealed pole 52 is connected to the pole fixing plate 63 through fasteners, and the thickness of the epoxy resin on the back of the sealed pole 52 is greater than the thickness of the epoxy resin on the remaining part of the outer side.

[0039] Furthermore, in order to ensure the insulation inside the gas box body and thus effectively reduce the overall size of the switch assembly, the gas box body of the present invention is filled with SF6 gas or other insulating gas.

[0040] Example 2 like Figure 1 、 2 As shown in Figures 3, 4, 5, 6, 7, 8, 9 and 10, a miniaturized 40.5kV ring main unit includes an instrument room 1, a mechanism room 2 and a cable room 3, and the instrument room 1 is located above the mechanism room 2, and the cable room 3 is located below the mechanism room 2. It also includes the miniaturized 40.5kV ring main unit gas box 4 as mentioned above, which is arranged on one side of the mechanism room 2 and side by side with it, and the three-position switch 54 is also electrically connected to the cable in the cable room 3.

[0041] The specific working process of the ring main unit gas box in Examples 1 and 2 of the present invention is as follows: the circuit breaker is responsible for cutting off and connecting the power to ensure the stable movement of the system; the three-position switch 54 integrates the functions of the isolating switch and the grounding switch, and has the functions of circuit connection, circuit isolation, and grounding maintenance; like Figure 3 As shown, when the circuit breaker is closed, the circuit breaker arm 533 rotates counterclockwise and pushes the insulating pull rod 532 to move, thereby driving the transmission plate 531 to rotate. The transmission plate 531 drives the transmission block 511 and the arc extinguishing chamber movable end 521 to move downward. When the circuit breaker moves, after the arc extinguishing chamber movable end 521 is closed, the circuit breaker arm 533 continues to rotate counterclockwise and compresses the spring 5323 of the insulating pull rod 532, providing contact pressure between the arc extinguishing chamber movable end 521 and the static contact in the vacuum interrupter 523. At this time, the knife switch 541 of the three-position switch 54 contacts the isolation contact 522. like Figure 4 As shown, when the circuit breaker is opened, the circuit breaker arm 533 rotates in the opposite direction and pulls the insulating pull rod downward, synchronously driving the transmission plate 531 to rotate, causing the transmission block 511 to move upward under the drive of the transmission plate 531, and the arc extinguishing chamber moving end 521 is separated from the static contact in the vacuum arc extinguishing chamber 523, achieving opening. At this time, the knife switch 541 of the three-position switch 54 is still in contact with the isolation contact 522; like Figure 5 As shown, when the three-position switch 54 is in the closed position, the knife switch arm 545 rotates (counterclockwise) and drives the knife switch 541 to rotate clockwise to the isolation position through the insulating connecting rod 543 and the insulating plate 542. At this time, the isolation contact 522 is separated from the knife switch 541, and the arc extinguishing chamber moving end 521 is separated from the static contact in the vacuum arc extinguishing chamber 523, and is in the open state; like Figure 6 As shown, when the line needs to be grounded for maintenance, the knife switch arm 545 continues to rotate counterclockwise, and continues to drive the knife switch 541 to rotate clockwise through the insulating connecting rod 543 and the insulating plate 542 until the knife switch 541 contacts the grounding contact 544. At this time, the moving end 521 of the arc extinguishing chamber is separated from the static contact in the vacuum arc extinguishing chamber 523 and is in the open state.

[0042] The present invention adopts a small solid-sealed pole solution and integrates it with a three-position switch. At the same time, the integrated frame structure is not only compact but also easy to install. Compared with the transmission solid-sealed pole, the height is reduced, and the position of the transmission mechanism is changed from the vertical pole direction to the side (back) direction, which also enhances the structural strength and reduces the overall height of the pole. At the same time, the present invention fully utilizes the side space to set the transmission components, achieving miniaturization.

[0043] The three-phase circuit of the present invention adopts an independent structure, has no inter-phase leakage or creepage path, and reduces the risk of inter-phase short circuit.

[0044] The structural mode of fixed connection between the movable contact seat and the sealed pole of the present invention not only ensures the electrical conduction function, but also the structural form of the movable contact seat provides transmission support and shielding of sharp corners and burrs in the high-voltage structure, and uniform electric field function. At the same time, it also reduces the number of parts, and the overall structure is compact, which conforms to the miniaturization design concept.

[0045] To sum up, the 40.5kV ring main unit gas box and its ring main unit targeted by the present invention not only have an overall miniaturized structure, but the ring main unit also adopts gas-sealed insulation, making the product safer and more reliable. The special miniaturized solid-sealed pole side-mounting solution reduces the overall height; and the three-phase circuits of the present invention are independent of each other, there is no risk of phase-to-phase creepage, and the insulation performance is also more superior.

[0046] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A miniaturized 40.5 kV ring main unit gas box, comprising a gas box body, the interior of the gas box body being filled with insulating gas, and provided with a switch assembly (5) and a mounting frame (6). The connection terminal at the top of the switch assembly (5) serves as a busbar connection terminal, and the outlet terminal at the bottom serves as a cable connection terminal. Its characteristics are: The switch assembly (5) includes a circuit breaker and a three-position switch (54), wherein the circuit breaker has three-phase units A, B, and C with the same structure and arranged vertically separately, and each phase unit includes a movable contact seat (51), a sealed pole (52), and a closing and opening transmission mechanism (53), wherein the movable contact seat (51) is fixed on the top of the sealed pole (52), and the sealed pole (52) is arranged on one side of the mounting frame (6) and is detachably connected thereto, and the closing and opening transmission mechanism (53) and the three-position switch (54) are both arranged on the mounting frame (6), and the closing and opening transmission mechanism (53) is located between the sealed pole (52) and the mounting frame (6), and the three-position switch (54) is located below the sealed pole (52). The movable contact seat (51) is provided with a transmission block (511) that is slidably engaged therewith, and the transmission block (511) is fixedly connected to the arc extinguishing chamber movable end (521) at the top of the sealed pole (52). The transmission block (511) is transmission-connected to the closing and opening transmission mechanism (53), and the isolating contact (522) provided at the bottom of the sealed pole (52) is separated from or connected to the three-position switch (54).

2. The miniaturized 40.5kV ring main unit gas box according to claim 1 is characterized in that: A top expansion sleeve (71) is provided on the upper portion of the gas box body, and an electrically connected connecting busbar (81) is also provided on the moving contact seat (51), and the connecting busbar (81) is electrically connected to a connector at the bottom of the top expansion sleeve (71). An outlet sleeve (72) is provided on the lower side of the gas box body, and the three-position switch (54) is connected via a connecting copper rod (82) and a connector on the side of the outlet sleeve (72).

3. The miniaturized 40.5kV ring main unit gas box according to claim 1 is characterized in that: The closing and opening transmission mechanism (53) includes a transmission plate (531), an insulating pull rod (532) and a circuit breaker arm (533); the circuit breaker arm (533) is rotatably connected to the mounting frame (6) and rotates around the circuit breaker arm shaft hole (61) of the mounting frame (6); the transmission plate (531) is rotatably connected to the movable contact seat (51); the two ends of the insulating pull rod (532) are rotatably connected to the transmission plate (531) and the circuit breaker arm (533), respectively; a guide slot (512) is provided on the movable contact seat (51); the transmission block (511) is connected to the transmission plate (531) and slides along the guide slot (512) under the driving action of the transmission plate (531).

4. The miniaturized 40.5kV ring main unit gas box according to claim 3 is characterized in that: The insulating pull rod (532) includes an insulating rod (5321), a sliding rod (5322) and a spring (5323). The sliding rod (5322) and the insulating rod (5321) are fixed as a whole, and the insulating rod (5321) is rotatably connected to the transmission plate (531). The spring (5323) is mounted on the sliding rod (5322), and both ends of the spring (5323) are respectively against the baffle (5325) provided on the sliding rod (5322). At the same time, the sliding rod (5322) is also rotatably connected to the circuit breaker arm (533).

5. The miniaturized 40.5kV ring main unit gas box according to claim 4 is characterized in that: The insulating rod (5321) is rotatably connected to the transmission plate (531) via a ball bearing screw (5324), and the sliding rod (5322) is also rotatably connected to the circuit breaker arm (533) via a pin in a shaft sleeve (5326) at its end.

6. The miniaturized 40.5kV ring main unit gas box according to claim 1, characterized in that: The bottom of the movable contact seat (51) is provided with a plurality of contact finger grooves (513) arranged coaxially, the outer periphery of the arc extinguishing chamber movable end (521) is provided with a plurality of spring contact fingers (514), and each spring contact finger (514) is arranged in a corresponding contact finger groove (513), and at the same time, the arc extinguishing chamber movable end (521) is fixedly connected to the transmission block (511) by a fastening bolt (515).

7. The miniaturized 40.5kV ring main unit gas box according to claim 1, characterized in that: The sealed pole (52) has a vacuum interrupter (523), and the outer periphery of the vacuum interrupter (523) is coated with epoxy resin (524). A static contact is provided inside the vacuum interrupter (523), which is arranged opposite to the interrupter moving end (521) with a gap therebetween, and the static contact is fixedly connected to the isolation contact (522).

8. The miniaturized 40.5kV ring main unit gas box according to claim 1, characterized in that: The bottom of the sealed pole (52) has a positioning groove (525) for forming a positioning match with the isolation contact (522).

9. The miniaturized 40.5kV ring main unit gas box according to claim 1, characterized in that: The three-position switch (54) comprises a knife switch (541), an insulating plate (542), an insulating connecting rod (543), a grounding contact (544), a knife switch arm (545) and a conductive block (546), wherein the grounding contact (544) is fixed on the mounting frame (6), the knife switch arm (545) is rotatably connected to the mounting frame (6), and an insulating connection is formed between the conductive block (546) and the mounting frame (6), the knife switch (541) is fixedly connected to the insulating plate (542), and the insulating plate (542) is rotatably connected to the knife switch arm (545) via the insulating connecting rod (543), one end of the knife switch (541) is rotatably connected to the isolating contact (522), and the other end forms a conductive and rotatable connection with the conductive block (546).

10. The miniaturized 40.5kV ring main unit gas box according to claim 9, characterized in that: The mounting frame (6) has a grounding contact fixing plate (65), the grounding contact (544) is fixed on the grounding contact fixing plate (65), and a buffer pad (547) is provided between the grounding contact (544) and the grounding contact fixing plate (65).

11. The miniaturized 40.5kV ring main unit gas box according to claim 9, characterized in that: The mounting frame (6) has an insulator fixing plate (66), and the conductive block (546) forms an insulating connection with the insulator fixing plate (66) via an insulator (548).

12. The miniaturized 40.5kV ring main unit gas box according to claim 3, characterized in that: The mounting frame (6) comprises a side plate (62) and a pole fixing plate (63) fixedly connected to the side plate (62), and the sealed pole (52) is detachably connected to the pole fixing plate (63).

13. The miniaturized 40.5kV ring main unit gas box according to claim 12, characterized in that: The pole fixing plate (63) has a diagonal support plate (64) for enhancing structural strength, the diagonal support plate (64) has a circuit breaker crank arm shaft hole (61), and the circuit breaker crank arm (533) is rotatably connected to the diagonal support plate (64).

14. The miniaturized 40.5kV ring main unit gas box according to claim 7, characterized in that: The mounting frame (6) has a pole fixing plate (63), the epoxy resin (524) on the back of the sealed pole (52) is connected to the pole fixing plate (63) via a fastener, and the thickness of the epoxy resin on the back of the sealed pole (52) is greater than the thickness of the epoxy resin on the remaining portion outside the pole.

15. A miniaturized 40.5 kV ring main unit, comprising an instrument room (1), a mechanism room (2) and a cable room (3), wherein the instrument room (1) is located above the mechanism room (2) and the cable room (3) is located below the mechanism room (2), characterized in that: It also includes a miniaturized 40.5kV ring main unit gas box (4) as described in any one of claims 1 to 14 above, wherein the ring main unit gas box is arranged on one side of the mechanism room (2) and arranged side by side therewith, and the three-position switch (54) is also electrically connected to the cable in the cable room (3).

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