Primary and secondary fusion ring network box

Abstract

The application discloses a primary and secondary fusion ring network box and relates to the technical field of ring network boxes, and aims to solve the technical problem of switch contact lacking the ability to block derived electric arc. The application is characterized in that a triple synergistic structure of "grid piece segmentation + gas cooling + physical plugging" is adopted to efficiently extinguish electric arc and block derived electric arc, thereby solving the problem of secondary discharge in a harsh environment. With the help of paraffin phase change material for heat storage and release, the inner wall temperature is stably maintained, the formation of electrolyte film due to condensation is avoided, and the insulation performance is ensured. A shape memory alloy is used to drive an isolation structure to be sealed in normal state, opened during arc and closed after arc extinction, and a one-way valve is used to discharge harmful gas. A linkage ventilation system is used to replace residual harmful gas with dry gas, dilute conductive particles and reduce humidity, and the four functions are synergistically used to protect in multiple dimensions, such as arc extinguishing, condensation prevention, harmful gas isolation and residual removal, so that the operation stability and safety of the ring network box under complex working conditions are greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ring main unit, more particularly to a primary and secondary fusion ring main unit. BACKGROUND

[0002] In the 10-24kV distribution network system, the primary and secondary fusion ring main unit is the core equipment of line control and fault isolation, which is widely used in urban distribution network, industrial park and various outdoor scenes. The reliable arc extinguishing capability of the switch part (circuit breaker, load switch) of the ring main unit directly determines the safe operation of the distribution network. If the arc generated by the switch breaking is not effectively controlled, it is easy to cause equipment damage, fault expansion, and even threaten the safety of the operation and maintenance personnel. At present, the mainstream ring main unit switch body integrates a vacuum arc chamber or an SF6 gas arc chamber, which can automatically extinguish 2000 to 5000℃ load current and small short-circuit current arc, responds quickly and does not require manual intervention, and can meet the basic needs of conventional environments such as urban indoor and dry outdoor environments.

[0003] In actual distribution network operation, 2000 to 5000℃ arc is a high-frequency working condition, which mainly occurs in two scenarios: one is the breaking of 630A to 1250A rated load current (daily high-frequency operation) of the circuit breaker / load switch, and the other is the breaking of 3 to 5kA small-capacity short-circuit current (small-scale fault downstream). Although the energy of this type of arc is lower than that of the extreme short-circuit arc, the existing arc extinguishing means has significant limitations and cannot fully cover the hazards.

[0004] Firstly, the existing arc extinguishing only protects the "point-to-point" of the switch contact, and lacks the blocking ability of the derived arc. The metal vapor generated by the switch breaking is easy to diffuse to cause gap discharge, or splash to the busbar joint to form a local arc. Especially in coastal salt spray, high humidity, and dusty environments, salt spray and condensation form an electrolyte film on the surface of the insulating part, and the metal vapor attached to it is easy to cause secondary discharge; in the dust environment, the arc may also ignite the dust, which has the risk of explosion. Operation and maintenance data show that in coastal areas, ring main units without protection often have problems such as carbonization of insulating parts and busbar creepage. Secondly, the long-term cumulative hazards of high-frequency arc are difficult to avoid. For the switch body, the high temperature of the arc will cause contact ablation and arc chamber pollution, shorten the service life of the contact, increase the probability of arc reignition, and may also cause the operation mechanism to jam; for the surrounding elements, arc heat radiation and metal particles will burn the insulating part, aggravate the busbar joint discharge, and interfere with the work of DTU, sensor and other secondary elements; for the distribution network operation, incomplete arc treatment is easy to cause breaking failure, fault expansion, and even switch "false tripping", which brings safety hazards. The existing arc extinguishing means can only meet the basic needs of conventional environments, and cannot solve the problem of derived arc in harsh environments. In view of this, we propose a primary and secondary fusion ring main unit. SUMMARY

[0005] The purpose of the present application is to provide a primary and secondary fusion ring network box to solve the technical problem of switch contact lacking arc blocking ability.

[0006] To solve the above technical problems, the present application provides the following technical solutions: a primary and secondary fusion ring network box, comprising a ring network box body, a primary and secondary device group is arranged inside the ring network box body, a control switch is arranged on the primary and secondary device group, a plurality of switch doors are rotatably connected to one side of the ring network box body, and a fixed lock is installed on the switch door.

[0007] An electrically isolated base is fixed to the position close to the control switch on the inner side of the switch door, an electrically isolated sleeve is fixed to one side of the electrically isolated base, the electrically isolated sleeve and the electrically isolated base are made of electrically isolated material, an inner concave annular groove is formed on one side of the electrically isolated sleeve, a rubber sealing ring is bonded in the annular groove, and the rubber sealing ring is tightly attached to the outer peripheral area of the control switch when the switch door is closed.

[0008] An arc extinguishing structure is arranged on the inner periphery of the electrically isolated sleeve, the arc extinguishing structure comprises a ceramic ring, a plurality of through holes are formed in the ceramic ring, a metal grid ring is connected to the outer ring of the ceramic ring, an isolation arc extinguishing plate is filled in the gap between the grid fins of the metal grid ring, the isolation arc extinguishing plate is made of an expanded arc extinguishing material, the isolation arc extinguishing plate can instantaneously expand and release arc extinguishing gas when triggered by arc high temperature, and an air outlet pipe is connected between the outer peripheral bottom of the electrically isolated base and the exhaust groove of the ring network box body.

[0009] Preferably, the metal grid ring is composed of a grid ring shell and a grid outer cover, a heat preservation space is arranged between the grid ring shell and the grid outer cover, and the heat preservation space is filled with a phase change material.

[0010] Preferably, a one-way valve is fixed to the center of one end of the electrically isolated sleeve close to the rubber sealing ring, a fixed frame is fixed to the outer periphery of the one-way valve, a plurality of separation openings are arranged on the fixed frame, and a plurality of isolation structures are arranged on one end of the electrically isolated sleeve.

[0011] Preferably, the isolation structure comprises an isolation plate with the same size as the separation opening, an elastic sealing strip is fixed to the outer peripheral edge of the isolation plate; the isolation plate is in a fan arc structure, a plurality of isolation driving members are fixed to the outer arc edge of the isolation plate, a deformation cavity is formed on one end of the electrically isolated sleeve, and a pressure receiving surface is arranged on the deformation cavity.

[0012] Preferably, the isolation driving member comprises a hard connection plate fixed to the isolation plate, the hard connection plate is rotatably connected to the electrically isolated sleeve, a bent pressure arc piece is fixed to one side of the hard connection plate, the outer periphery of the bent pressure arc piece is attached to the inner wall of the deformation cavity, one end of the bent pressure arc piece is in contact with the pressure receiving surface, and the isolation plate and the bent pressure arc piece are made of a shape memory alloy that can be deformed.

[0013] Preferably, the electrically isolated sleeve is provided with a pressurized cavity at one end, and the pressurized cavity is internally provided with a gas exchange structure.

[0014] Preferably, the gas exchange structure comprises a pressurized ring, which is an annular plate structure, the pressurized ring is limitedly slid with the pressurized cavity, two soft rubber layers are connected between one side of the pressurized ring and the pressurized cavity, a gas storage space is formed between the pressurized ring and the two soft rubber layers, and a spring is connected between the pressurized ring and the pressurized cavity.

[0015] Preferably, the gas storage space is connected with an exhaust pipe penetrating through the electrically isolated sleeve and communicating with the inner wall space between the rubber sealing ring and the fixed frame, and the gas storage space is also connected with an air inlet pipe, the air inlet pipe is composed of a wave folded pipe and a hard pipe, and a one-way valve is installed on the air inlet pipe and the exhaust pipe.

[0016] Preferably, one end of the pressurized ring is provided with a round chamfer facilitating extrusion, and a pressing piece is arranged above one end of the pressurized ring, the pressing piece is composed of a driving section and a stabilizing section, the driving section is an arc structure with gradually increasing diameter and taking the hard connecting plate rotation point as the center, and the stabilizing section is an arc structure with the same distance from the hard connecting plate rotation point.

[0017] Preferably, a detachable ring is detachably fixed at the position of the hard connecting plate rotation point of the electrically isolated sleeve.

[0018] Compared with the prior art, the application has the following beneficial effects:

[0019] 1. By adopting the triple arc extinguishing structure of "grid piece segmentation + gas cooling + physical plugging", when the switch is broken, the metal grid ring first divides the electric arc into a short arc to reduce the energy stability; the isolation arc extinguishing plate (boric acid zinc-mica composite medium) is triggered by high temperature to release arc extinguishing gas to cool the electric arc, and at the same time, the volume is expanded by three to five times to plug the gap between the grid pieces and the gap of the sleeve, physically block the electric arc channel and air supplement, cooperate with the closed space formed by the electrically isolated sleeve and the rubber sealing ring, and completely extinguish the electric arc to avoid the secondary discharge caused by the diffusion of metal vapor, effectively solve the problems of carbonization of insulating parts, bus bar creeping and other faults in coastal salt mist and high humidity environment.

[0020] 2. By filling paraffin phase change material in the metal grid ring, the arc high temperature is quickly conducted to the heat preservation space through the grid piece, the paraffin gradually melts from solid to liquid, and a large amount of heat is absorbed and stored; after the arc is extinguished, the paraffin cools and solidifies to release heat, so that the temperature of the metal grid ring and the inner wall of the electrically isolated sleeve is stably maintained at a temperature higher than the dew point of the environment, which effectively inhibits the generation of condensed water, avoids the combination of water droplets, metal vapor and salt to form an electrolyte film, guarantees the insulation reliability of the ring net box in high humidity, salt mist and other harsh environments, and prolongs the service life of the equipment.

[0021] 3、The invention also designs a shape memory alloy driven isolation structure, in normal state, the isolation plate is sealed to the fixed frame at the separation port, preventing gas from contacting the control switch peripheral area; when arc is generated, high temperature triggers the bending and pressing arc piece (high temperature nickel titanium niobium alloy) to millisecond deformation, driving the isolation plate to quickly spin open, providing a smooth channel for the arc and arc extinguishing gas; after arc extinguishing, the alloy elastic recovery makes the isolation plate close and seal, cooperating with the one-way valve to discharge harmful gas, completely blocking the contact between residual gas and the control switch and busbar lap joint, avoiding gap discharge and insulation deterioration, and ensuring the normal work of primary and secondary equipment groups.

[0022] 4、The invention also integrates a gas exchange system linked with the isolation structure, when arc is generated, the hard connection plate rotation drives the extrusion piece to push the pressure ring to slide, and dry gas in the ring network box is sucked through the air inlet pipe; after arc extinguishing, the isolation plate resets the end, and the spring pushes the pressure ring to move back, and the dry gas is flushed into the closed space through the exhaust pipe to displace and neutralize the residual metal vapor and conductive particles, which not only dilutes harmful gas and improves the insulation strength of the local space, but also reduces humidity and inhibits condensation, greatly reduces the risk of secondary discharge without interfering with the arc extinguishing process, and ensures the cleanliness of the equipment surrounding environment.

[0023] 5、The invention also adopts modular integrated design, the electrically isolated jacket is linked with the switch door, and the closed space can be constructed by closing the switch door without additional operation; the shape memory alloy driven isolation structure does not need complex limiting guide, and realizes automatic opening and closing through material characteristics, and the response speed matches the arc time sequence, at the same time, the disassembly ring on the electrically isolated jacket is convenient for maintaining and replacing core components, the soft air outlet pipe is matched with the opening and closing action of the switch door, does not affect the normal operation of the equipment, the overall structure is compact, does not interfere with the operation of the control switch, DTU, sensor and other primary and secondary equipment, retains the basic function of the traditional ring network box, and adds multiple protections, and adapts to the use requirements of multiple scenes such as urban distribution network and industrial park. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of the invention;

[0025] Figure 2 It is an internal structure schematic diagram of the invention;

[0026] Figure 3 It is an internal structure schematic diagram of a single switch door in the invention;

[0027] Figure 4 It is a connection structure schematic diagram of the jacket part in the invention;

[0028] Figure 5 It is a half-section structure schematic diagram of the jacket part in the invention;

[0029] Figure 6This is a schematic diagram of the fixing frame in this invention;

[0030] Figure 7 This is a half-section schematic diagram of the arc-extinguishing structure in this invention;

[0031] Figure 8 This is a schematic diagram of the disassembled structure of the arc-extinguishing structure in this invention;

[0032] Figure 9 For the present invention Figure 5 Enlarged view of the structure at point A in the middle;

[0033] Figure 10 This is a schematic diagram of a single isolation structure under normal conditions in this invention;

[0034] Figure 11 This is a half-section diagram of a single isolation structure in the present invention when it is in contact with an electric arc;

[0035] Figure 12 For the present invention Figure 11 Enlarged view of the structure at point B;

[0036] Figure 13 This is a schematic diagram of a single isolation structure of the present invention when it is in contact with an electric arc.

[0037] Explanation of the labels in the diagram:

[0038] 1. Ring network enclosure; 2. Primary and secondary equipment group; 3. Control switch; 4. Switch door; 5. Fixed lock; 6. Isolation base; 7. Isolation jacket; 8. Rubber sealing ring; 9. Arc extinguishing structure; 10. Air outlet pipe; 11. One-way valve; 12. Fixing frame; 121. Separation port; 13. Isolation structure; 14. Deformation cavity; 141. Pressure surface; 15. Compressed air cavity; 16. Ventilation structure; 17. Extrusion component; 18. Disassembly ring;

[0039] 901. Ceramic ring; 902. Metal grille ring; 9021. Grille ring shell; 9022. Grille outer cover; 903. Isolation arc extinguishing plate; 131. Isolation plate; 132. Isolation drive component; 1321. Rigid connecting plate; 1322. Bending and pressing arc plate; 161. Pressure ring; 162. Soft rubber layer; 163. Air storage space; 164. Spring; 165. Exhaust pipe; 166. Intake pipe; 171. Pressure driving section; 172. Stabilizing section. Detailed Implementation

[0040] like Figures 1 to 13 As shown, the present invention relates to a primary and secondary integrated ring network box, including a ring network box body 1, a primary and secondary equipment group 2 is arranged inside the ring network box body 1, a control switch 3 is arranged on the primary and secondary equipment group 2, and a plurality of switch doors 4 are rotatably connected to one side of the ring network box body 1, and a fixed lock 5 is installed on the switch doors 4.

[0041] The electrically isolated base 6 is fixed at a position close to the control switch 3 on the inner side of the switch door 4, and the electrically isolated sleeve 7 is fixed on one side of the electrically isolated base 6, both of which are made of electrically isolated materials; a concave annular groove is formed on one side of the electrically isolated sleeve 7, and a rubber sealing ring 8 is bonded in the annular groove; when the switch door 4 is closed, the rubber sealing ring 8 is tightly attached to the outer peripheral area of the control switch 3, and the elastic design of the rubber sealing ring 8 allows it to tightly attach to the outer periphery of the control switch 3, thereby achieving the closure of the space.

[0042] An arc extinguishing structure 9 is arranged on the inner periphery of the electrically isolated sleeve 7, which includes a ceramic ring 901 having a plurality of through holes, and a metal grid ring 902 connected to the outer ring of the ceramic ring 901, and an isolation arc extinguishing plate 903 filled in the gaps between the grid fins of the metal grid ring 902; the isolation arc extinguishing plate 903 is made of an expanded arc extinguishing material, which can be instantaneously expanded and release arc extinguishing gas when triggered by arc high temperature, and an air outlet pipe 10 is connected between the outer peripheral bottom of the electrically isolated base 6 and the exhaust groove of the ring net box body 1; each ring net box body 1 is provided with an exhaust groove, and the air outlet pipe 10 is made of soft material to facilitate the opening and closing of the switch door 4.

[0043] The material of the isolation arc extinguishing plate 903 is preferably zinc borate-mica composite solid arc extinguishing medium, which can release CO2 and H2O arc extinguishing gas and expand three to five times in volume when heated to a temperature of 800℃ or above, thereby quickly plugging the gaps between the grid fins and the inner wall of the sleeve, physically isolating the arc channel and blocking air supply, achieving triple arc extinguishing of "grid fin segmentation + gas cooling + physical plugging", and the isolation arc extinguishing plate 903 can also be made of other similar materials.

[0044] Working principle: close the switch door 4 and lock it with the fixed lock 5, the rubber sealing ring 8 on one side of the electrically isolated sleeve 7 is tightly attached to the outer peripheral area of the control switch 3 by means of elasticity, and the electrically isolated materials of the electrically isolated base 6 and the electrically isolated sleeve 7 form a closed space outside the control switch 3, preventing the arc from spreading to other areas inside the ring net box body 1 and avoiding the secondary discharge caused by the arc.

[0045] When the control switch 3 breaks and generates an arc (temperature ≥800℃), the grid fins of the metal grid ring 902 first divide the arc into multiple short arcs, reducing the arc energy and stability; at the same time, the isolation arc extinguishing plate 903 (zinc borate-mica composite solid medium) in the gap between the grid fins is triggered by the high temperature of the arc, causing it to rapidly decompose and release CO2 and H2O arc extinguishing gas, which quickly diffuses in the closed space, cooling the arc and diluting the arc zone conductive particles, weakening the arc conductive ability.

[0046] The isolation arc-extinguishing plate 903 expands by three to five times in volume during decomposition, tightly seals the gaps between the latticed sheets of the metal latticed ring 902 and the inner wall gaps of the electrically isolated outer sleeve 7, physically blocks the arc channel and air replenishment, realizes "arc-extinguishing without oxygen supply", and the exhaust gas and excess gas generated by arc-extinguishing are discharged through the soft exhaust pipe 10 at the bottom of the electrically isolated base 6, guided to the exhaust groove of the ring network box body 1, avoids the influence of gas accumulation on the arc-extinguishing effect, and finally completely extinguishes the arc.

[0047] Further, the high-temperature gas generated in the process of arc-extinguishing will condense after the arc is extinguished, resulting in the generation of an electrolyte film. In order to reduce or avoid the occurrence of condensation, the following structure is designed.

[0048] The metal latticed ring 902 is composed of a latticed ring shell 9021 and a latticed outer cover 9022, and a heat preservation space is arranged between the latticed ring shell 9021 and the latticed outer cover 9022, which is filled with a phase change material, preferably paraffin.

[0049] Working principle: when the control switch 3 breaks and generates an arc, the high temperature (≥800℃) is transmitted to the heat preservation space between the latticed ring shell 9021 and the latticed outer cover 9022 through the latticed sheets of the metal latticed ring 902, and the paraffin phase change material in the heat preservation space changes from solid to liquid after being heated, absorbs a large amount of heat generated by the arc during this phase change process and stores it, avoiding the rapid diffusion of heat leading to sudden temperature rise and fall.

[0050] When the arc is extinguished by the arc-extinguishing structure 9, the internal environment temperature of the ring network box body 1 begins to drop, at this time, the paraffin phase change material gradually cools down and releases the stored heat, which is transmitted to the latticed sheets of the metal latticed ring 902 and the inner wall of the electrically isolated outer sleeve 7 through the latticed ring shell 9021, continuously maintaining the temperature of the inner wall area.

[0051] The latent heat of the paraffin phase change material is large, the heat storage and release process is gentle and long-lasting, and the temperature of the metal latticed ring 902 and the inner wall of the electrically isolated outer sleeve 7 can be stably maintained above 50℃ (much higher than the environmental dew point temperature), which is sufficient to inhibit the condensation of high-temperature arc-extinguishing gas after cooling, avoid the formation of electrolyte film on the surface of the insulating part, eliminate the risk of secondary discharge caused by metal vapor attachment, and ensure the insulation performance of the ring network box in harsh environments such as high humidity and salt spray.

[0052] The phase change temperature of the paraffin phase change material is about 58℃, the latent heat of phase change can reach 200-250kJ / kg, and the heat release after single heat storage can last for more than 30 minutes, which can stably maintain the inner wall temperature at 50-60℃. This temperature range can effectively avoid the generation of condensate water (the environmental dew point temperature is usually lower than 30℃), and will not affect the normal work of the surrounding elements due to the temperature being too high, completely meeting the use requirements of anti-condensation.

[0053] Further, in the process of extinguishing the arc, metal vapor and ionized conductive particles may be mixed in the arc-extinguishing gas. If not discharged in time, it will reduce the gas insulation strength in the closed space, easily cause gap discharge or secondary arc at the control switch 3 peripheral elements and busbar lap joint, aggravate the carbonization and creep risk of the insulation piece, affect the normal work of the primary and secondary equipment group 2. In view of this point, the following structure is designed.

[0054] The one-way valve 11 is fixed at the center of one end of the electrically isolated sleeve 7 close to the rubber sealing ring 8, the outer periphery of the one-way valve 11 is fixed with a fixed frame 12, the fixed frame 12 is provided with a plurality of separation ports 121, and the electrically isolated sleeve 7 is provided with a plurality of isolation structures 13 at one end.

[0055] The isolation structure 13 comprises an isolation plate 131 with the same size as the separation port 121, and the outer periphery of the isolation plate 131 is fixed with an elastic sealing strip; the isolation plate 131 is in a fan arc structure, a plurality of isolation driving elements 132 are fixed on the outer arc edge of the isolation plate 131, and a deformation cavity 14 is formed at one end of the electrically isolated sleeve 7, and the deformation cavity 14 is provided with a pressure receiving surface 141.

[0056] The isolation driving element 132 comprises a hard connection plate 1321 fixed with the isolation plate 131, the hard connection plate 1321 is rotationally connected with the electrically isolated sleeve 7, one side of the hard connection plate 1321 is fixed with a bent pressure arc piece 1322, the outer periphery of the bent pressure arc piece 1322 is attached to the inner wall of the deformation cavity 14, one end of the bent pressure arc piece 1322 is in contact with the pressure receiving surface 141, and the isolation plate 131 and the bent pressure arc piece 1322 are made of a deformable shape memory alloy.

[0057] The isolation plate 131 and the bent pressure arc piece 1322 are preferably made of high-temperature nickel-titanium-niobium (Ni-Ti-Nb) shape memory alloy, which has the characteristics of "millisecond thermal response deformation + instantaneous elastic recovery", the deformation speed can match the speed of the arc, and the control of the deformation only needs to preset the shapes before and after the deformation during manufacturing, which can be realized through the material characteristics of itself, without the need to set a limiting or guiding structure, and the "instantaneity" of the arc is reflected in "fast discharge start" (≤1ms), but the physical moving speed is relatively slow (gas diffusion characteristics); while the deformation of the SMA valve is "thermal driven instantaneous deformation", and there is almost no delay between high-temperature conduction and alloy phase change, the deformation speed is much higher than the moving speed of the arc, and there is no problem of "valve not opened, arc arrived".

[0058] Working principle: after the switch door 4 is closed, the isolation plate 131 of the isolation structure 13 is precisely connected with the separation port 121 of the fixed frame 12, the elastic sealing strip on the outer periphery of the isolation plate 131 is tightly attached to the inner wall of the separation port 121, forming a closed state, at this time, the outer periphery of the bent pressure arc piece 1322 is tightly attached to the inner wall of the deformation cavity 14, further strengthening the sealing effect, preventing the internal gas of the ring network box from directly contacting the peripheral area of the control switch 3, and avoiding the attachment of harmful gas.

[0059] When the control switch 3 is disconnected to generate an electric arc (temperature ≥800℃), high temperature is rapidly conducted to the bending and pressing arc piece 1322 (high-temperature nickel-titanium-niobium shape memory alloy), triggering the alloy millisecond-level thermal response deformation. During the deformation of the bending and pressing arc piece 1322, one end extrudes the pressure surface 141 of the pressure cavity 14, drives the hard connection plate 1321 to rotate around the connecting point of the electrically isolated outer sleeve 7, and further drives the fan-shaped isolation plate 131 to rotate open synchronously, rapidly opening the separation port 121 of the fixed frame 12, forming a smooth channel, ensuring that the electric arc and the arc extinguishing gas smoothly enter the arc extinguishing structure 9 region inside the electrically isolated outer sleeve 7 without affecting the arc extinguishing process.

[0060] After the electric arc is extinguished, the ambient temperature rapidly decreases, and the bending and pressing arc piece 1322 and the isolation plate 131 are instantaneously reversely deformed and reset under the elastic recovery characteristics of the shape memory alloy. The hard connection plate 1321 drives the isolation plate 131 to re-close the separation port 121, and the elastic sealing strip is tightly sealed again. At the same time, the one-way valve 11 at the center of the electrically isolated outer sleeve 7 remains open under the internal gas pressure after arc extinguishing, guiding the harmful gas mixed with metal vapor and conductive particles to the exhaust pipe 10 for discharge. After the gas is discharged, the one-way valve 11 is closed, cooperating with the closure of the isolation plate 131, completely blocking the contact of the residual harmful gas with the surrounding elements of the control switch 3 and the bus joint, avoiding the risk of gap discharge, secondary arc, and carbonization and creeping of the insulation parts, and ensuring the normal work of the primary and secondary equipment group 2.

[0061] Further, in order to reduce the retention of arc extinguishing gas again.

[0062] The electrically isolated outer sleeve 7 is provided with a gas pressing cavity 15 at one end, and a gas exchange structure 16 is arranged inside the gas pressing cavity 15.

[0063] The gas exchange structure 16 includes a pressure receiving ring 161, which is a ring-shaped plate structure. The pressure receiving ring 161 is limited to slide with the gas pressing cavity 15. Two soft rubber layers 162 are connected between one side of the pressure receiving ring 161 and the gas pressing cavity 15. A gas storage space 163 is formed between the pressure receiving ring 161 and the two soft rubber layers 162. A spring 164 is connected between the pressure receiving ring 161 and the gas pressing cavity 15, and the force of the spring 164 is much smaller than the driving force.

[0064] The gas storage space 163 is connected with an exhaust pipe 165 penetrating through the electrically isolated outer sleeve 7 and communicating with the inner wall space between the rubber sealing ring 8 and the fixed frame 12. The gas storage space 163 is also connected with an air inlet pipe 166, which is composed of a wave-shaped folding pipe and a hard pipe. A one-way valve is installed on each of the air inlet pipe 166 and the exhaust pipe 165.

[0065] The one end of the pressure ring 161 is provided with a round chamfer for easy extrusion, and the one end of the pressure ring 161 is provided with an extrusion piece 17, which is composed of a driving section 171 and a stabilizing section 172. The driving section 171 is connected with the hard connection plate 1321, and the driving section 171 is in an arc structure with gradually increasing diameter and takes the rotation point of the hard connection plate 1321 as the center. The stabilizing section 172 is in an arc structure with the same distance from the rotation point of the hard connection plate 1321.

[0066] Working principle: when the control switch 3 generates an electric arc, the hard connection plate 1321 of the isolation driving piece 132 is driven to rotate by high temperature, and the extrusion piece 17 is synchronously rotated. In the initial stage, the driving section 171 (arc structure with gradually increasing diameter) of the extrusion piece 17 is in contact with the round chamfer of the pressure ring 161. With the continuous rotation, the extrusion force is continuously applied to push the pressure ring 161 to slide along the limit of the gas compression cavity 15, compress the spring 164 and extrude the gas storage space 163. At this time, the one-way valve on the gas inlet pipe 166 is opened, the dry gas in the ring net box 1 is sucked into the gas storage space 163 for storage, and the one-way valve of the exhaust pipe 165 is closed to avoid gas backflow.

[0067] When the hard connection plate 1321 rotates to a preset angle, the stabilizing section 172 (arc structure with equal distance from the rotation point) of the extrusion piece 17 is in contact with the pressure ring 161. At this time, no additional extrusion force is generated, the pressure ring 161 remains in a fixed position, and the gas storage volume of the gas storage space 163 is maintained to prepare for subsequent gas exchange, while the normal arc extinguishing of the arc extinguishing structure 9 is not affected.

[0068] After the electric arc is extinguished, the hard connection plate 1321 drives the extrusion piece 17 to rotate reversely and reset. In the reset stage, the stabilizing section 172 is still in contact with the pressure ring 161, and the pressure ring 161 remains stationary. When the reset is to the end stage, the isolation plate 131 is about to contact the separation opening 121 of the fixed frame 12, the extrusion piece 17 is switched to the driving section 171 opposite to the pressure ring 161, the spring 164 releases the elastic potential energy, pushes the pressure ring 161 to quickly return, and compresses the dry gas in the gas storage space 163. At this time, the one-way valve of the exhaust pipe 165 is opened, the dry gas is flushed into the space between the rubber sealing ring 8 and the fixed frame 12 through the exhaust pipe 165, and the residual arc extinguishing gas (containing metal vapor and conductive particles) is replaced and neutralized to reduce the retention of harmful gas.

[0069] The above operation is to close first and then replace. After the replacement of the gas, even if there is a small amount of gas that has not been replaced, the dry gas input can quickly dilute the residual metal vapor and ionized conductive particles, improve the gas insulation performance of the space between the rubber sealing ring 8 and the fixed frame 12, avoid the gap discharge and secondary arc caused by the retention of harmful gas, reduce the carbonization of the insulation piece and the risk of bus creeping from the root, and ensure the stable operation of the primary and secondary equipment group 2. Moreover, the dry gas can reduce the humidity of the local space and reduce the condensation probability of water vapor in the residual arc extinguishing gas.

[0070] The whole process is linked with the opening and closing of the isolation structure 13, which greatly reduces the insulation deterioration and secondary discharge risk caused by residual gas without interfering with the arc extinction process, and guarantees the cleanliness of the control switch 3 surrounding area.

[0071] Need to be explained, bending pressure arc piece 1322 adopts high temperature nickel titanium niobium (Ni-Ti-Nb) shape memory alloy is made, phase change recovery force can reach 200-300MPa, far higher than the driving force required by the driving pressure ring 161.

[0072] The above-mentioned one-way valve can adopt the existing one-way valve or the one-way design of the valve form, which can adopt the existing technology here.

[0073] Further, in order to facilitate maintenance and disassembly, the electrically isolated sleeve 7 is detachably fixed with a disassembly ring 18 at the rotation point position of the hard connection plate 1321.

[0074] The embodiments of the present application are disclosed, but not limited to the above, and those skilled in the art can easily understand the spirit of the present application according to the above embodiments, and make different inferences and changes, as long as they do not deviate from the spirit of the present application, they are within the protection scope of the present application.

Claims

1. A primary / secondary fusion ring box, characterized in that, Including ring network box (1), ring network box (1) inside be provided with a secondary equipment group (2), the secondary equipment group (2) is provided with control switch (3), ring network box (1) one side rotatably connected with multiple switch doors (4); The switch door (4) inboard is fixed with the electrically isolated base (6) near the control switch (3), the electrically isolated base (6) one side is fixed with the electrically isolated cover (7), the electrically isolated cover (7) and electrically isolated base (6) are made of electrically isolated material, the electrically isolated cover (7) one side is provided with the recessed annular groove, the rubber sealing ring (8) is bonded in the annular groove, when the switch door (4) is closed, the rubber sealing ring (8) and the outer circumferential region of control switch (3) are tightly attached; The arc extinguishing structure (9) is arranged on the inner circumferential surface of the electrically isolated cover (7), the arc extinguishing structure (9) comprises a ceramic ring (901), the ceramic ring (901) is provided with a plurality of through holes, the outer ring of the ceramic ring (901) is connected with a metal grid ring (902), the grid sheet gap of the metal grid ring (902) is filled with an isolation arc extinguishing plate (903), the isolation arc extinguishing plate (903) is made of an expanded arc extinguishing material, the isolation arc extinguishing plate (903) is triggered by arc high temperature and can be expanded and release arc extinguishing gas instantaneously, the outer circumferential bottom of the electrically isolated base (6) is connected with the gas outlet pipe (10) between the exhaust groove of the ring network box (1); The metal grid ring (902) is composed of a grid ring shell (9021) and a grid outer cover (9022), a heat preservation space is arranged between the grid ring shell (9021) and the grid outer cover (9022), and the heat preservation space is filled with a phase change material; The one-way valve (11) is fixed at the center of one end of the electrically isolated cover (7) close to the rubber sealing ring (8), the outer circumferential surface of the one-way valve (11) is fixed with a fixing frame (12), a plurality of separation openings (121) are arranged on the fixing frame (12), and a plurality of isolation structures (13) are arranged at one end of the electrically isolated cover (7); The isolation structure (13) comprises an isolation plate (131) with the same size as the separation opening (121), and the outer circumferential edge of the isolation plate (131) is fixed with an elastic sealing strip; the isolation plate (131) is in a fan arc structure, a plurality of isolation driving members (132) are fixed to the outer arc edge of the isolation plate (131), and a deformation cavity (14) is formed at one end of the electrically isolated cover (7); and a pressure receiving surface (141) is arranged on the deformation cavity (14).

2. The one-two hybrid ring box of claim 1, wherein, The isolation driving member (132) comprises a hard connecting plate (1321) fixed to the isolation plate (131), the hard connecting plate (1321) is rotatably connected with the electrically isolated cover (7), a bent pressure arc piece (1322) is fixed to one side of the hard connecting plate (1321), the outer circumferential surface of the bent pressure arc piece (1322) is attached to the inner wall of the deformation cavity (14), one end of the bent pressure arc piece (1322) is in contact with the pressure receiving surface (141), and the isolation plate (131) and the bent pressure arc piece (1322) are made of a shape memory alloy which can be deformed.

3. The one-two hybrid ring box of claim 2, wherein, The electrically isolated sheath (7) is provided with a pressurized cavity (15) at one end, and the pressurized cavity (15) is internally provided with a ventilation structure (16).

4. The one-two hybrid ring box of claim 3, wherein, The ventilation structure (16) comprises a pressure ring (161), which is an annular plate body structure, and the pressure ring (161) is in limited sliding connection with the pressurized cavity (15). Two soft rubber layers (162) are connected between one side of the pressure ring (161) and the pressurized cavity (15), and a gas storage space (163) is formed between the pressure ring (161) and the two soft rubber layers (162). A spring (164) is connected between the pressure ring (161) and the pressurized cavity (15).

5. The one-two hybrid ring box of claim 4, wherein, The gas storage space (163) is connected with an exhaust pipe (165) penetrating through the electrically isolated sheath (7) and communicating with the inner wall space between the rubber sealing ring (8) and the fixed frame (12). The gas storage space (163) is also connected with an air inlet pipe (166), which is composed of a wave-shaped folding pipe and a hard pipe. A one-way valve is installed on the air inlet pipe (166) and the exhaust pipe (165).

6. The one-two hybrid ring box of claim 5, wherein, The pressure ring (161) is provided with a round chamfer at one end for easy extrusion. An extrusion piece (17) is arranged above one end of the pressure ring (161). The extrusion piece (17) is composed of a driving section (171) and a stabilizing section (172). The driving section (171) is in an arc structure with gradually increasing diameter and takes the rotation point of the hard connecting plate (1321) as the center. The stabilizing section (172) is in an arc structure with the same distance from the rotation point of the hard connecting plate (1321).

7. The one-two hybrid ring box of claim 6, wherein, The electrically isolated sheath (7) is detachably fixed with a detachable ring (18) at the rotation point of the hard connecting plate (1321).

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