A highly reliable ring main unit

Abstract

This utility model belongs to the field of ring main units, specifically relating to a high-reliability ring main unit, including a cabinet, a disconnecting switch, and three top-expanding bushings. Each top-expanding bushing includes an epoxy resin casting and a conductive component. One end of the conductive component has a stationary contact extending inside the contact insulation cover of the epoxy resin casting for cooperating with the isolating blade of the disconnecting switch. Two elastic clamping pieces are provided on the conductive component corresponding to both sides of the stationary contact. When the isolating blade is connected to the stationary contact, the clamping force of the two elastic clamping pieces causes the isolating blade to exert pressure towards the stationary contact. The addition of two elastic clamping pieces to the conductive component increases the contact pressure between the isolating blade and the stationary contact of the top-expanding bushing, thereby improving the contact reliability between the disconnecting switch and the top-expanding bushing. The gas-filled top-expanding bushing is made of epoxy resin casting, and the stationary contact is set inside the contact insulation cover of the epoxy resin casting, increasing the insulation distance between the three top-expanding bushings and improving insulation performance.

Description

Technical Field

[0001] This utility model belongs to the field of ring main unit technology, and specifically relates to a high-reliability ring main unit. Background Technology

[0002] Currently, a ring main unit (RNB) is an electrical device consisting of a group of power transmission and distribution equipment (high-voltage switchgear) housed in a metal or non-metal insulated cabinet or assembled into a modular ring network power supply unit. Its core components utilize load switches and fuses, offering advantages such as simple structure, small size, low price, improved power supply parameters and performance, and enhanced power supply safety. It is widely used in substations and prefabricated substations in load centers such as urban residential areas, high-rise buildings, large public buildings, and factories. It typically uses sulfur hexafluoride gas, environmentally friendly gases, or epoxy resin as the insulating medium. For the rapidly developing power industry, the development of environmentally friendly gas-insulated RNBs is an inevitable trend. Future power transmission and distribution equipment will inevitably continue to evolve around the demands for safety, reliability, miniaturization, and environmental friendliness. Because the insulating properties of existing environmentally friendly gases such as nitrogen and dry air are far lower than those of sulfur hexafluoride gas, there are very high requirements for the insulation performance of environmentally friendly gas-insulated RNBs.

[0003] The existing ring main unit has insufficient contact pressure between the top expansion bushing and the disconnecting switch, resulting in unreliable contact between the stationary contact of the top expansion bushing and the isolating blade of the disconnecting switch. In addition, the stationary contact of the top expansion bushing is exposed outside the insulation layer, resulting in a small creepage distance between multiple top expansion bushings, which cannot meet the insulation requirements of environmentally friendly gas-insulated ring main units. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings and deficiencies of the existing technology and provide a highly reliable ring main unit that can effectively increase the contact pressure between the static contact of the top expansion bushing and the disconnecting switch, thereby effectively improving the contact reliability between the top expansion bushing and the disconnecting switch.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A high-reliability ring main unit includes a cabinet, a disconnecting switch disposed within the cabinet, and three top expansion sleeves disposed on the cabinet. Each top expansion sleeve includes an epoxy resin casting body disposed on the cabinet and a conductive element disposed within the epoxy resin casting body. One end of the conductive element has a stationary contact extending within the contact insulation cover of the epoxy resin casting body for cooperating with the disconnecting blade of the disconnecting switch. Two elastic clamping pieces are disposed on the conductive element corresponding to both sides of the stationary contact. When the disconnecting blade is connected to the stationary contact, the clamping force of the two elastic clamping pieces causes the disconnecting blade to apply pressure toward the stationary contact.

[0006] In some embodiments, each of the elastic clamping pieces has a planar clamping portion at one end. When the isolation blade is connected to the stationary contact, the planar clamping portions of the two elastic clamping pieces respectively abut against the two sides of the isolation blade.

[0007] In some embodiments, each of the elastic clamping pieces has a beveled guide portion that transitions to the planar clamping portion, and when the isolation blade is closed, the isolation blade slides along the beveled guide portion onto the planar clamping portion.

[0008] In some embodiments, each of the elastic clamping pieces has a fixing portion at the other end, and the conductive member is provided with two insulating pressure plates that abut against the fixing portions of the two elastic clamping pieces. Each of the two insulating pressure plates is provided with a screw, which passes through the insulating pressure plate and the fixing portion in sequence and is connected to the conductive member.

[0009] In some embodiments, the other end of the conductive element has a wiring portion, the wiring portion has a wiring hole exposed outside the cabinet, and the wiring portion is provided with a plurality of protruding rings that fit into the epoxy resin casting body.

[0010] In some embodiments, the epoxy resin casting body is provided with a skirt separating the contact insulation cover and the cabinet.

[0011] In some embodiments, a plurality of isolation protrusions are arranged at intervals inside the contact insulation cover corresponding to the area below the stationary contact.

[0012] In some embodiments, the stationary contact is T-shaped, and the stationary contact and the conductive element are integrally formed.

[0013] In some embodiments, a fixing plate is provided on the outer wall of the cabinet corresponding to the three top expansion sleeves, and a plurality of fasteners are respectively provided on the fixing plate. A plurality of copper inserts connected to the plurality of fasteners are respectively provided in the epoxy resin casting bodies of the three top expansion sleeves.

[0014] In some embodiments, the fixing plate has two vertically bent flanges on both sides.

[0015] The beneficial effects of this utility model are as follows: Two elastic clamping pieces are added to the conductive component. The two elastic clamping pieces can increase the contact pressure between the isolating blade and the stationary contact of the top expansion bushing, thereby improving the contact reliability between the isolating switch and the top expansion bushing. The gas top expansion bushing is made of epoxy resin casting, and the stationary contact is set inside the contact insulation cover of the epoxy resin casting body, which increases the insulation distance between the three top expansion bushings and helps to improve the insulation performance. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, obtaining other drawings based on these drawings without creative effort still falls within the scope of this utility model.

[0017] Figure 1 This is a perspective view of an embodiment of the present utility model; Figure 2 This is a cross-sectional view of an embodiment of the present utility model; Figure 3 This is a structural diagram of the conductive component in an embodiment of the present invention; Figure 4 This is a perspective view of the elastic clamping sheet according to an embodiment of the present invention. Detailed Implementation

[0018] To make the technical problem to be solved, the technical solution, and the beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0020] The directional and positional terms used in this utility model, such as up, down, front, back, left, right, inside, outside, top, bottom, side, etc., are only for reference to the accompanying drawings. Therefore, the directional and positional terms used are for the purpose of explaining and understanding this utility model, and not for limiting the scope of protection of this utility model.

[0021] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments: like Figure 1-4As shown, a high-reliability ring main unit includes a cabinet 1, a disconnecting switch 2 installed inside the cabinet 1, and three top expansion sleeves 3 installed on the cabinet 1. Each top expansion sleeve 3 includes an epoxy resin casting body 31 installed on the cabinet 1 and a conductive element 32 installed inside the epoxy resin casting body 31. One end of the conductive element 32 has a stationary contact 321 extending inside the contact insulation cover 311 of the epoxy resin casting body 31 for cooperating with the disconnecting blade 21 of the disconnecting switch 2. Two elastic clamping pieces 33 are provided on the conductive element 32 at both sides corresponding to the stationary contact 321. When the disconnecting blade 2 is connected to the stationary contact 321, the clamping force of the two elastic clamping pieces 33 causes the disconnecting blade 2 to apply pressure toward the stationary contact 321.

[0022] like Figure 1 , 3 As shown in Figure 4, one end of the elastic clamping piece 33 has a flat clamping portion 331. When the isolating blade 21 is connected to the stationary contact 321, the flat clamping portions 331 of the two elastic clamping pieces 33 respectively abut against both sides of the isolating blade 21. The elastic clamping pieces abut against the isolating blade through the flat clamping portions, thereby ensuring that the clamping force of the elastic clamping pieces can reliably act on the isolating blade, which is beneficial to improving the contact reliability between the isolating blade and the stationary contact. Moreover, the contact area between the elastic clamping pieces and the isolating blade through the flat clamping portions is increased, which is beneficial to the heat dissipation of the isolating blade. The elastic clamping piece 33 has an inclined guide portion 332 that transitions to the flat clamping portion 331. When the isolating blade 21 performs closing, the isolating blade 21 slides along the inclined guide portion 332 onto the flat clamping portion 331. The inclined guide portion guides the isolating blade, ensuring that the clamping force of the elastic clamping pieces can be reliably applied to the isolating blade, which is beneficial to improving the contact reliability between the isolating blade and the stationary contact. Each elastic clamping piece 33 has a fixing part 333 at its other end. The conductive member 32 is provided with two insulating pressure plates 34 that abut against the fixing parts 333 of the two elastic clamping pieces 33. Each of the two insulating pressure plates 34 is provided with a screw 35. The screw 35 passes through the insulating pressure plate 34 and the fixing part 333 in sequence and is connected to the conductive member 32. The screws press the elastic clamping pieces to the conductive member through the insulating pressure plates, thereby ensuring a tighter connection between the elastic clamping pieces and the conductive member.

[0023] like Figure 1 and 2As shown, the other end of the conductive component 32 has a wiring portion 322, which has a wiring hole 323 exposed outside the cabinet 1. Multiple protruding rings 324 are provided on the wiring portion 322 to fit within the epoxy resin casting body 31. The wiring portion of the conductive component is fitted into the epoxy resin casting body through multiple protruding rings, thereby ensuring a more secure connection between the conductive component and the epoxy resin casting body. A skirt 312 is provided on the epoxy resin casting body 31 to separate the contact insulation cover 311 from the cabinet 1. The skirt increases the creepage distance between the stationary contact and the cabinet, which is beneficial for improving insulation performance. Multiple isolation protrusions 3111 are arranged at intervals inside the contact insulation cover 311 corresponding to the area below the stationary contact 321. The isolation protrusions increase the creepage distance between the stationary contact and the disconnect switch, which is beneficial for improving insulation performance. The stationary contact 321 is T-shaped, and the stationary contact 321 and the conductive component 32 are integrally formed. The stationary contact adopts a T-shaped structure design, which ensures reliable contact between the stationary contact and the isolating blade. The stationary contact and the conductive component adopt an integrated structure design, resulting in better conductivity. Fixing plates 4 are installed on the outer wall of the cabinet 11 corresponding to the three top expansion sleeves 3. Multiple fasteners 5 are installed on the fixing plates 4, and multiple copper inserts 6 connected to the fasteners 5 are respectively installed within the epoxy resin castings 31 of the three top expansion sleeves 3. The three top expansion sleeves are integrated on the fixing plates, facilitating the assembly of the three top expansion sleeves with the cabinet and improving assembly efficiency. The fixing plates 4 have two vertically bent flanges 41 on both sides. The two flanges enhance the strength of the fixing plates and ensure reliable connection between the fixing plates and the three top expansion sleeves.

[0024] Two elastic clamping pieces are added to the conductive parts. These two elastic clamping pieces can increase the contact pressure between the isolating blade and the stationary contact of the top expansion bushing, thereby improving the contact reliability between the isolating switch and the top expansion bushing. The gas top expansion bushing is made of epoxy resin casting, and the stationary contact is set inside the contact insulation cover of the epoxy resin casting body, which increases the insulation distance between the three top expansion bushings and helps to improve the insulation performance.

[0025] The above description is only one embodiment of the present utility model and is not intended to limit the scope of protection of the present utility model; the scope of protection of the present utility model is defined by the claims in the claims, and all equivalent changes and modifications made in accordance with the utility model are within the scope of protection of the present utility model patent.

Claims

1. A high-reliability ring main unit, characterized in that: The device includes a cabinet, a disconnecting switch installed inside the cabinet, and three top expansion sleeves installed on the cabinet. Each top expansion sleeve includes an epoxy resin casting body installed on the cabinet and a conductive element installed inside the epoxy resin casting body. One end of the conductive element has a stationary contact extending inside the contact insulation cover of the epoxy resin casting body for cooperating with the disconnecting blade of the disconnecting switch. Two elastic clamping pieces are provided on the conductive element on both sides corresponding to the stationary contact. When the disconnecting blade is connected to the stationary contact, the clamping force of the two elastic clamping pieces causes the disconnecting blade to apply pressure toward the stationary contact.

2. The high-reliability ring main unit according to claim 1, characterized in that: Each of the aforementioned elastic clamping pieces has a flat clamping portion at one end. When the isolation blade is connected to the stationary contact, the flat clamping portions of the two elastic clamping pieces respectively abut against the two sides of the isolation blade.

3. The high-reliability ring main unit according to claim 2, characterized in that: Each of the aforementioned elastic clamping pieces has a beveled guide portion that transitions to the planar clamping portion. When the isolation blade is closed, it slides along the beveled guide portion onto the planar clamping portion.

4. The high-reliability ring main unit according to claim 2 or 3, characterized in that: Each of the elastic clamping pieces has a fixing part at the other end. The conductive element is provided with two insulating pressure plates that abut against the fixing parts of the two elastic clamping pieces. Each of the two insulating pressure plates is provided with a screw. The screw passes through the insulating pressure plate and the fixing part in sequence and is connected to the conductive element.

5. The high-reliability ring main unit according to claim 1, characterized in that: The other end of the conductive component has a wiring portion, which has a wiring hole exposed outside the cabinet body, and the wiring portion is provided with multiple protruding rings that fit into the epoxy resin casting body.

6. The high-reliability ring main unit according to claim 1, characterized in that: The epoxy resin casting body is provided with a skirt that separates the contact insulation cover and the cabinet.

7. The high-reliability ring main unit according to claim 6, characterized in that: Multiple isolation ridges are arranged at intervals inside the contact insulation cover, corresponding to the position below the stationary contact.

8. The high-reliability ring main unit according to claim 1, characterized in that: The stationary contact is T-shaped, and the stationary contact and the conductive component are integrally formed.

9. The high-reliability ring main unit according to claim 1, characterized in that: The outer wall of the cabinet is provided with fixing plates corresponding to the three top expansion sleeves. Each fixing plate is provided with multiple fasteners. Each of the three top expansion sleeves has multiple copper inserts connected to the multiple fasteners in the epoxy resin casting body.

10. The high-reliability ring main unit according to claim 9, characterized in that: The fixing plate has two vertically bent flanges on both sides.

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