An arc suppression and isolation device inside a ring main unit

Abstract

This invention discloses an internal arc suppression and isolation device for ring main units, relating to the field of ring main unit technology. It includes a sealing plate movably inserted inside a fixed frame for sealing; movable rods symmetrically inserted on both sides of the fixed frame for limiting the sealing plate; a movable column movably positioned on the other side of the movable rods to sense arcing and generate thrust displacement; a pressing plate movably positioned on one side of the sealing plate for pushing it to seal; a cylindrical outer shell and piston rod symmetrically positioned on one side of the pressing plate to sense arcing and generate thrust; and an annular plate symmetrically positioned within a square outer shell to reduce airflow. This invention cleverly utilizes the characteristics of paraffin wax melting and expanding in volume when heated and the temperature rising when an arc is generated. A sealing plate that can fall and seal with temperature changes is provided at the heat dissipation holes, while an annular plate that can close the channel after high temperatures is provided at the wiring holes, thus suppressing and isolating the arc and improving the safety of the ring main unit.

Description

Technical Field

[0001] This invention relates to the field of ring main unit technology, specifically to an internal arc suppression and isolation device for a ring main unit. Background Technology

[0002] The internal arc suppression and isolation device of the ring main unit is a key protection system designed for internal arc accidents caused by equipment aging, operational errors, insulation failures or foreign object intrusion in the distribution network. It can greatly limit the destructive energy generated by the arc, ensure the safety of equipment and personnel, and is an important technical equipment for improving the reliability of the distribution network.

[0003] Arcing in ring main units is usually caused by insulation aging, foreign object intrusion, operational overvoltage, or equipment defects leading to phase-to-phase or phase-to-ground breakdown discharge. Existing ring main units are generally composed of multiple standardized functional cabinets (such as incoming line cabinets, outgoing line cabinets, metering cabinets, PT cabinets, etc.) spliced ​​together. This is mainly for modular design, standardized manufacturing, and flexibility for later expansion and maintenance. Each compartment is designed with a directional pressure relief channel at the top.

[0004] Ring main units rely on air convection for heat dissipation during use, so ventilation holes must be provided. The energy released by the electric arc is extremely fast, and the pressure inside the cabinet rises sharply within milliseconds when the pressure relief channel is fully opened. This pressure may temporarily exceed the bearing capacity of all weak points. The instantaneous extremely high pressure generated by the electric arc may still cause some high-temperature gas and arc products to leak directly and unobstructed from non-sealed gaps such as ventilation holes and wiring holes, igniting adjacent cabinets or causing fires outside the cabinet.

[0005] To address the aforementioned issues, there is an urgent need for innovative designs based on the existing arc suppression and isolation devices within the ring main unit. Summary of the Invention

[0006] The present invention addresses the problem of overly simplistic solutions in existing technologies by providing a significantly different solution. Specifically, the present invention aims to provide an internal arc suppression and isolation device for ring main units, thereby solving the problem mentioned in the background art where, when an arc is generated in a ring main unit, the extremely high instantaneous pressure generated by the arc may still cause some high-temperature gases and arc products to leak directly from non-sealed gaps such as heat dissipation holes and wiring holes, igniting adjacent cabinets or causing fires outside the cabinet.

[0007] To achieve the above objectives, the present invention provides the following technical solution: an arc suppression and isolation device for a ring main unit, comprising a ring main unit body and a fixing frame fixed inside the ring main unit body, and further comprising: A sealing plate that is movable and inserted inside the fixed frame for sealing; The movable rods symmetrically inserted on both sides of the fixed frame are used to limit the position of the sealing plate. The movable column, located on the other side of the movable rod, senses the electric arc and generates thrust displacement. An active pressure plate located on one side of the sealing plate is used to push it to seal. A cylindrical outer shell and piston rod symmetrically arranged on one side of the extrusion plate to sense the electric arc and generate thrust; A square outer shell fixed in the main body of the ring main unit to protect adjacent cabinets; A ring-shaped plate symmetrically arranged within a square casing to reduce airflow.

[0008] Preferably, the front of the main body of the ring main unit is hinged with a door panel, and the inner wall of the door panel is fixed with a fixing frame. The door panel is provided with heat dissipation holes, and the position of the heat dissipation holes is adapted to the position of the sealing plate; The fixed frame is symmetrically provided with sliding grooves, and the end of the sliding groove facing the back plate is opened through.

[0009] Preferably, the inner wall of the ring main unit is provided with a wiring hole, and a wire is provided in the wiring hole, and a square shell is fixed on the surface of the wire; Movable rods are inserted into both sides of the square shell, and a ring plate is fixed to one side of the inner wall of the square shell through the movable rods. A second spring is fixed to the other side of the moving rod.

[0010] Preferably, circular shells are symmetrically fixed on both sides of the fixed frame, and movable columns are movably inserted into the circular shells; The bottom of the circular outer shell is covered with paraffin wax, and the top of the paraffin wax is in contact with the bottom of the movable column.

[0011] Preferably, the top of the sealing plate is symmetrically provided with irregularly shaped grooves, and a movable rod is movably inserted into the irregularly shaped grooves; The edge of the irregular groove has protrusions and recesses, the distance between the protrusions is less than the diameter of the movable rod, and the diameter of the recesses is greater than the diameter of the movable rod; A return spring is wound around the surface of the movable rod at the end located on the inner wall of the circular outer shell, and the two ends of the return spring are fixed to the inner wall of the circular outer shell and the surface of the movable rod, respectively.

[0012] Preferably, a movable rod is inserted laterally on one side of the circular outer shell, and one end of the movable rod movably passes through the fixed frame and extends into the sealing plate; The movable rod consists of two parts: a sphere and a cylinder. The sphere is fixed to one side and the surface of the cylinder. The end of the movable rod that contacts the movable column has an inclined surface, and the inclined surface is adapted to the diameter of the movable column.

[0013] Preferably, the cylindrical outer shell is symmetrically fixed on one side of the fixed frame, and a piston rod is movably inserted into the cylindrical outer shell; The cylindrical outer shell contains paraffin wax; A return spring is wound around the surface of the piston rod, and the two sides of the return spring are fixed to the surface of the piston rod and one side of the cylindrical outer shell, respectively.

[0014] Preferably, the extrusion plate is movably inserted into the fixed frame, and one side of the extrusion plate is in contact with the sealing plate; One end of the piston rod is fixed to one side of the extrusion plate.

[0015] Preferably, the movable column consists of two sets of connecting columns with different diameters; The surface of the movable column is wound with a first spring, and the two ends of the first spring are in contact with the inner wall of the circular outer shell and the surface of the movable column, respectively.

[0016] Preferably, a paraffin column is provided on the other side of the second spring, and the second spring is in contact with the paraffin column; The surface of the paraffin column is fitted with a hollow shell, and the hollow shell is fixed to the inner wall of the ring main unit. The inner wall of the hollow shell is provided with an arc-shaped groove that is compatible with the paraffin column; The hollow outer shell has equally spaced cylindrical grooves at its middle end.

[0017] Compared with the prior art, the beneficial effects of the present invention are: This invention cleverly utilizes the characteristics of paraffin wax expanding in volume upon heating and the temperature rising when an electric arc is generated. It upgrades passive protection to active intelligent sealing. A sealing plate that falls and seals the ventilation holes according to temperature changes is installed. When the temperature rises, the movable column rises and pushes the movable rod to move, causing the sealing plate to fall and be pushed by the compression plate to block the ventilation holes. At the same time, a ring plate that can close the channel when the wiring hole is hot is installed. In the instant that an arc fault occurs, it automatically and quickly replenishes and seals the air in the cabinet. It physically and quickly solves the two key potential leakage paths of ventilation holes and wiring holes in real time, and seals the high temperature gas and plasma generated by the arc inside the cabinet. It enhances the directional release effect of the pressure relief channel, reduces the possibility of arc energy and flame leaking to adjacent cabinets or outside the cabinet through the gaps, suppresses and isolates the arc, and improves the safety, reliability and protection level of the ring main unit for surrounding personnel and equipment. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the first three-dimensional structure of the present invention.

[0019] Figure 2 This is a schematic diagram of the second three-dimensional structure of the present invention.

[0020] Figure 3 This is a schematic diagram of the third three-dimensional structure of the present invention.

[0021] Figure 4 This is a three-dimensional structural diagram of the fixing frame and sealing plate of the present invention.

[0022] Figure 5 This is a three-dimensional cross-sectional structural diagram of the circular outer shell of the present invention.

[0023] Figure 6 This is a three-dimensional structural diagram of the movable column and movable rod of the present invention.

[0024] Figure 7 This is a three-dimensional structural diagram of the movable rod and irregular groove of the present invention.

[0025] Figure 8 This is a three-dimensional cross-sectional structural diagram of the cylindrical shell of the present invention.

[0026] Figure 9 This is a three-dimensional rear view structural diagram of the fixed frame of the present invention.

[0027] Figure 10 This is a three-dimensional structural diagram of the square outer shell of the present invention.

[0028] Figure 11 This is a three-dimensional structural diagram of the annular plate and the movable rod of the present invention.

[0029] Figure 12 This is a three-dimensional structural diagram of the hollow column and paraffin column of the present invention.

[0030] Figure 13 This is a schematic diagram showing the usage state of the fixing frame and sealing plate of the present invention.

[0031] In the diagram: 1. Main body of the ring main unit; 2. Fixed frame; 3. Square outer shell; 4. Sealing plate; 5. Circular outer shell; 6. Columnar outer shell; 7. Extrusion plate; 8. Movable column; 9. Movable rod; 10. First spring; 11. Irregular groove; 12. Ring plate; 13. Moving rod; 14. Second spring; 15. Hollow outer shell; 16. Paraffin column; 17. Piston rod. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Please see Figures 1 to 13The present invention provides a technical solution: an arc suppression and isolation device inside a ring main unit, comprising a ring main unit body 1 and a fixing frame 2 fixed inside the ring main unit body 1, characterized in that it further comprises: A sealing plate 4 is inserted into the fixed frame 2 for sealing purposes; The movable rods 9, symmetrically inserted on both sides of the fixed frame 2, are used to limit the sealing plate 4. An active column 8, located on the other side of the active rod 9, senses the electric arc and generates thrust displacement. An active compression plate 7 is located on one side of the sealing plate 4 to push it to seal. A cylindrical outer shell 6 and a piston rod 17 are symmetrically arranged on one side of the extrusion plate 7 to sense the electric arc and generate thrust. A square outer shell 3 fixed in the main body 1 of the ring main unit to protect adjacent cabinets; Annular plates 12 are symmetrically arranged in the square outer casing 3 to reduce airflow.

[0034] Additionally, it should be noted that the main body 1 of the ring main unit is equipped with an arc detector, which can detect a strong light signal at the moment the arc is generated. The protection device then issues a command to make the circuit breaker of the upstream or local section trip quickly and cut off the fault current. It can quickly transform the unstable arc grounding into a stable metallic grounding to eliminate the arc and the overvoltage it causes. This is existing technology and will not be elaborated on here.

[0035] In practice, the front of the main body 1 of the ring main unit is hinged with a door panel, and the inner wall of the door panel is fixed with a fixing frame 2. The door panel has ventilation holes, and the position of the ventilation holes is adapted to the position of the sealing plate 4; The fixed frame 2 has symmetrically arranged sliding grooves, and the end of the sliding groove facing the back plate is opened through.

[0036] Additionally, it should be noted that... Figure 9 As shown, the sealing plate 4 is initially at the upper end of the fixed frame 2. After an electric arc is generated, it moves down to the lower end of the fixed frame 2. The groove at the lower end of the fixed frame 2 is wider. The sealing plate 4 tilts down as it moves down and then comes into contact with the heat dissipation hole.

[0037] In specific implementation, the inner wall of the main body 1 of the ring main unit is provided with a wiring hole, and a wire is provided in the wiring hole, and a square outer shell 3 is fixed on the surface of the wire. Movable rods 13 are inserted into both sides of the square outer shell 3, and an annular plate 12 is fixed to one side of the inner wall of the square outer shell 3. In addition, it should be noted that the ring plate 12 has a circular design that can wrap the circuit in the middle, relatively sealing the holes outside the circuit, reducing air leakage and diffusion, improving safety when an electric arc occurs, protecting adjacent cabinets, and further reducing the tripping problem of other cabinets. It is equivalent to "dynamically" rebuilding a complete sealed barrier for the cabinet at the moment of failure, firmly locking the arc products in the main body 1 of the ring main unit and the predetermined pressure relief channel, which greatly improves the directional pressure relief efficiency of the pressure relief channel.

[0038] A second spring 14 is fixed to the other side of the moving rod 13.

[0039] In specific implementation, circular shells 5 are symmetrically fixed on both sides of the fixed frame 2, and movable columns 8 are movably inserted into the circular shells 5; The bottom of the circular outer shell 5 is covered with paraffin wax, and the top of the paraffin wax is in contact with the bottom of the movable column 8.

[0040] Additionally, it should be noted that when the main body 1 of the ring main unit is operating normally, the paraffin wax is in a solid state and its volume is relatively small. The bottom end of the movable column 8 is located at the upper middle part of the paraffin wax chamber, and the first spring 10 is in an extended and unforced state. When an electric arc is generated in the main body 1 of the ring main unit, the paraffin wax in the circular outer shell 5 is heated and melts, increasing its volume and pushing the movable column 8 upwards. This pushes the bottom end of the movable column 8 to the top of the paraffin wax chamber. At this time, the first spring 10 is in a contracted and force-bearing state. It does not rely on the pressure difference after depressurization, but is triggered immediately when the electric arc begins and the temperature just rises. The phase change expansion speed of the paraffin wax is extremely fast, which can complete the sealing of key pores before the large-scale diffusion of high-temperature gas. The response speed is far superior to traditional passive protection.

[0041] In specific implementation, the top of the sealing plate 4 is symmetrically provided with irregular grooves 11, and a movable rod 9 is movably inserted in the irregular grooves 11; The edge of the irregular groove 11 has protrusions and recesses. The distance between the protrusions is less than the diameter of the movable rod 9, and the diameter of the recesses is greater than the diameter of the movable rod 9. A return spring is wound around the surface of the movable rod 9 at the end of the inner wall of the circular outer shell 5, and the two ends of the return spring are fixed to the inner wall of the circular outer shell 5 and the surface of the movable rod 9, respectively.

[0042] In specific implementation, a movable rod 9 is inserted horizontally on one side of the circular outer shell 5, and one end of the movable rod 9 moves through the fixed frame 2 and extends into the sealing plate 4; The movable rod 9 consists of two parts: a sphere and a cylinder. The sphere is fixed to one side and the surface of the cylinder. Additionally, it should be noted that... Figure 7As shown, the irregular groove 11 has a protrusion and a concave part. The surface of the movable rod 9 has a spherical protrusion. The diameter of the sphere is larger than the width of the protrusion. When the sphere is located at the protrusion of the irregular groove 11, it is limited in the sealing plate 4, so that the sealing plate 4 as a whole can be restricted to the upper end of the slide groove of the fixed frame 2. When the movable rod 9 is pushed and displaced, the diameter of the sphere is smaller than the width of the concave part. The sphere of the movable rod 9 is located at the concave part of the irregular groove 11 and no longer limits the sealing plate 4, so the sealing plate 4 can fall down.

[0043] The end of the movable rod 9 that contacts the movable column 8 has an inclined surface, and the inclined surface is adapted to the diameter of the movable column 8.

[0044] Additionally, it should be noted that... Figure 6 As shown, when the movable column 8 is in the initial position, the movable rod 9 is in contact with the small diameter end of the movable column 8, and the movable rod 9 is located between the upper and lower large diameter ends. When the movable column 8 moves upward, the large diameter end of the movable column 8 moves upward and pushes the inclined surface of the movable rod 9, causing it to move outward.

[0045] In practice, the cylindrical shell 6 is symmetrically fixed on one side of the fixed frame 2, and the piston rod 17 is movably inserted into the cylindrical shell 6; Paraffin wax is provided inside the cylindrical outer shell 6; In addition, it should be noted that the melting point of the paraffin in the cylindrical shell 6 is higher than that of the paraffin in the first spring 10. After the paraffin in the first spring 10 melts first, the sealing plate 4 is no longer limited and falls down. Subsequently, the volume of the paraffin melted in the cylindrical shell 6 increases, pushing the piston rod 17 and the extrusion plate 7 forward, pressing against the sealing plate 4 to further seal it, reduce the gap, and prevent high-temperature gas from being ejected from the personnel operation surface, providing more valuable escape time and safety guarantee for on-site personnel.

[0046] A return spring is wound around the surface of the piston rod 17, and the two sides of the return spring are fixed to the surface of the piston rod 17 and one side of the cylindrical housing 6, respectively.

[0047] In practice, the extrusion plate 7 is movably inserted into the fixed frame 2, and one side of the extrusion plate 7 is in contact with the sealing plate 4; One end of the piston rod 17 is fixed to one side of the extrusion plate 7.

[0048] Additionally, it should be noted that after the sealing plate 4 is lowered, the paraffin wax in the cylindrical outer shell 6 is also heated and melts, expanding in volume and pushing the piston rod 17 forward. As the piston rod 17 moves, it pushes the extrusion plate 7 forward, pressing the sealing plate 4 against the heat dissipation hole, thus sealing the cabinet where the electric arc is generated, isolating and suppressing the electric arc inside. Without the need for additional mechanical structures, the paraffin wax is simple, direct, reliable, and has strong anti-interference ability, and will not fail due to power outages or signal problems in emergency situations.

[0049] In practice, the movable column 8 consists of two sets of connecting columns with different diameters; A first spring 10 is wound around the surface of the movable column 8, and the two ends of the first spring 10 are in contact with the inner wall of the circular outer shell 5 and the surface of the movable column 8, respectively.

[0050] In specific implementation, a paraffin column 16 is provided on the other side of the second spring 14, and the second spring 14 is in contact with the paraffin column 16; a hollow shell 15 is fitted on the surface of the paraffin column 16, and the hollow shell 15 is fixed to the inner wall of the ring main body 1; the inner wall of the hollow shell 15 is provided with an arc-shaped groove that matches the paraffin column 16; and cylindrical grooves are provided at equal intervals at the middle end of the hollow shell 15.

[0051] Additionally, it should be noted that the paraffin pillar 16 above the hollow outer shell 15 melts when heated. The liquid flows down the cylindrical groove in the middle of the hollow outer shell 15 into the arc-shaped groove at the bottom of the hollow outer shell 15. After the temperature inside the cabinet recovers, the liquid paraffin pillar 16 re-solidifies into its initial solid form. Then, the paraffin pillar 16 is placed at the top of the hollow outer shell 15 for positioning. After the paraffin pillar 16 melts, the second spring 14 rebounds under force, causing the symmetrical moving rod 13 and the annular plate 12 to move towards the center simultaneously. This greatly reduces the risk of leakage due to the closure of the wiring hole gap, and reduces the leakage of air and electric arc.

[0052] Working principle: When using the arc suppression and isolation device inside the ring main unit, when an arc is generated in the main body 1 of the ring main unit, the arc probe inside can detect a strong light signal at the moment the arc is generated. The protection device then issues a command to make the circuit breaker of the upper level or this section trip quickly and cut off the fault current.

[0053] Subsequently, the temperature in the main body 1 of the ring main unit rises, and the paraffin in the circular outer shell 5 melts from solid to liquid and its volume increases. The usable space in the paraffin chamber decreases, and the liquid paraffin pushes the movable column 8 upward, pushing the bottom of the movable column 8 to the top of the paraffin chamber. At this time, the first spring 10 is in a contracted state.

[0054] When the movable column 8 moves upward, the large-diameter end of the movable column 8 moves upward and pushes the inclined surface of the movable rod 9, causing it to move outward. The return spring then stretches and deforms. The diameter of the spherical surface of the movable rod 9 is smaller than the width of the concave area. The shape of the movable rod 9 is pushed from the protrusion of the irregular groove 11 to the concave area and no longer limits the sealing plate 4. As a result, the sealing plate 4 moves down along the slide of the fixed frame 2 to the lower end of the fixed frame 2. The slide of the lower end of the fixed frame 2 is wider. When the sealing plate 4 moves down, it tilts and moves down to the horizontal position of the heat dissipation hole.

[0055] When the sealing plate 4 moves down, the volume of the molten paraffin in the cylindrical shell 6 increases, pushing the piston rod 17 to move outward, thereby pushing the extrusion plate 7 forward and further pressing against the sealing plate 4 to move towards the heat dissipation hole, making the heat dissipation hole sealed, and making it difficult for the electric arc and internal air to escape through the heat dissipation hole.

[0056] At the same time, the two sets of paraffin pillars 16 near the square outer shell 3 at the wiring hole melt from solid to liquid. The liquid flows along the cylindrical groove in the middle of the hollow outer shell 15 to the arc-shaped groove at the bottom of the hollow outer shell 15. At this time, the second spring 14 and the moving rod 13 are no longer restricted. The second spring 14 rebounds under force, causing the moving rod 13 to move forward. The annular plate 12 and the moving rod 13 move towards the middle at the same time, clamping the wires and reducing the gaps generated by the wiring. This reduces the leakage of air and electric arc to the adjacent cabinets, physically cutting off and reducing the two key potential leakage paths of the heat dissipation hole and the wiring hole in real time and thoroughly.

[0057] Finally, the staff will arrive for maintenance. At this time, the temperature inside the cabinet will return to normal and the paraffin will solidify. After opening the cabinet door, push the sealing plate 4 upward to reset it. When the two sets of movable rods 9 are moved to reset, the sealing plate 4 returns to the initial limit position, the heat dissipation holes are exposed and heat dissipation is restored. The liquid paraffin column 16 re-solidifies into the initial solid form in the hollow shell 15. Then, place the paraffin column 16 at the top limit of the hollow shell 15 to limit the moving rod 13 and the second spring 14. After the annular plate 12 is opened to both sides, the wiring hole is exposed.

[0058] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An internal arc suppression and isolation device for a ring main unit, comprising a ring main unit body (1) and a fixing frame (2) fixed inside the ring main unit body (1), characterized in that, Also includes: A sealing plate (4) is inserted into the fixed frame (2) for sealing. The movable rods (9) are symmetrically inserted on both sides of the fixed frame (2) to limit the sealing plate (4); An active column (8) is set on the other side of the active rod (9) to sense the electric arc and generate thrust displacement. The fixed frame (2) is symmetrically fixed with a circular shell (5) on both sides, and a movable column (8) is movably inserted in the circular shell (5). The bottom of the circular outer shell (5) is provided with paraffin wax, and the top of the paraffin wax is in contact with the bottom of the movable column (8); The top of the sealing plate (4) is symmetrically provided with irregular grooves (11), and a movable rod (9) is movably inserted in the irregular grooves (11). The edge of the irregular groove (11) is provided with protrusions and recesses, the distance between the protrusions is less than the diameter of the movable rod (9), and the diameter of the recesses is greater than the diameter of the movable rod (9); The surface of the movable rod (9) is wound with a return spring at the end of the inner wall of the circular outer shell (5), and the two ends of the return spring are fixed to the inner wall of the circular outer shell (5) and the surface of the movable rod (9), respectively. A movable rod (9) is inserted laterally on one side of the circular outer shell (5), and one end of the movable rod (9) moves through the fixed frame (2) and extends into the sealing plate (4); The movable rod (9) consists of two parts: a sphere and a cylinder. The sphere is fixed to one side and the surface of the cylinder. The end of the movable rod (9) that contacts the movable column (8) is provided with an inclined surface, and the inclined surface is adapted to the diameter of the movable column (8); An active pressure plate (7) is located on one side of the sealing plate (4) to push it to seal. A cylindrical outer shell (6) and a piston rod (17) are symmetrically arranged on one side of the extrusion plate (7) to sense the electric arc and generate thrust. The cylindrical shell (6) is symmetrically fixed on one side of the fixed frame (2), and a piston rod (17) is movably inserted into the cylindrical shell (6). The cylindrical outer shell (6) contains paraffin wax; The piston rod (17) is wound with a return spring, and the two sides of the return spring are fixed to the surface of the piston rod (17) and one side of the cylindrical shell (6), respectively. A square outer shell (3) is fixed in the main body (1) of the ring main unit to protect the adjacent cabinets; A ring plate (12) is symmetrically arranged in the square shell (3) to reduce airflow.

2. The arc suppression and isolation device inside a ring main unit according to claim 1, characterized in that: The front of the main body (1) of the ring main unit is hinged with a door panel, and the inner wall of the door panel is fixed with a fixing frame (2). The door panel is provided with heat dissipation holes, and the position of the heat dissipation holes is adapted to the position of the sealing plate (4); The fixed frame (2) is provided with symmetrical sliding grooves, and the end of the sliding groove facing the back plate is opened through.

3. The arc suppression and isolation device inside a ring main unit according to claim 1, characterized in that: The inner wall of the main body (1) of the ring network cabinet is provided with a wiring hole, and a wire is provided in the wiring hole, and a square shell (3) is fixed on the surface of the wire. Movable rods (13) are movably inserted on both sides of the square shell (3), and a ring plate (12) is fixed to one side of the inner wall of the square shell (3) where the movable rods (13) extend. A second spring (14) is fixed to the other side of the moving rod (13).

4. The arc suppression and isolation device inside a ring main unit according to claim 1, characterized in that: The extrusion plate (7) is movably inserted into the fixed frame (2), and one side of the extrusion plate (7) is in contact with the sealing plate (4); One end of the piston rod (17) is fixed to one side of the extrusion plate (7).

5. The arc suppression and isolation device inside a ring main unit according to claim 1, characterized in that: The movable column (8) consists of two sets of connecting columns with different diameters; The surface of the movable column (8) is wound with a first spring (10), and the two ends of the first spring (10) are in contact with the inner wall of the circular outer shell (5) and the surface of the movable column (8), respectively.

6. The arc suppression and isolation device inside a ring main unit according to claim 3, characterized in that: The second spring (14) has a paraffin column (16) on the other side, and the second spring (14) is in contact with the paraffin column (16); The surface of the paraffin column (16) is fitted with a hollow shell (15), and the hollow shell (15) is fixed to the inner wall of the main body (1) of the ring network cabinet; The inner wall of the hollow shell (15) is provided with an arc-shaped groove that is adapted to the paraffin column (16); The hollow outer shell (15) has cylindrical grooves at equal intervals at its middle end.

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