A pole-mounted circuit breaker for transient overload conditions

Abstract

The present application relates to the field of pole-mounted circuit breaker, especially to a pole-mounted circuit breaker for transient overload state, comprising a mechanism box, an operating mechanism and a movable plate which can move left and right are arranged inside the mechanism box, the operating mechanism can control the left and right movement of the movable plate, three vacuum circuit breaking chambers are installed at the upper end of the mechanism box, and a current transformer is installed at the rear side of each vacuum circuit breaking chamber; three contact opening and closing mechanisms, the contact opening and closing mechanism comprises a static conducting rod which is fixedly installed at the top of the vacuum circuit breaking chamber, and a static contact is installed at the lower end of the static conducting rod. Through the double-layer structure of the inner mesh and the outer cylinder, the metal vapor molecules collide multiple times between the two layers, gradually consume kinetic energy and improve condensation probability, significantly reduce the amount of vapor rebound, reduce the deposition of rebound vapor on the surface of the contact, thereby inhibiting the formation and expansion of contact spots. The movable design makes the vapor condensation and deposition uniformly distributed on the surface of the mesh, avoids local saturation, and prolongs the effective capture life of the shield.

Description

Technical Field

[0001] This invention relates to the field of pole-mounted circuit breakers, and more particularly to a pole-mounted circuit breaker for transient overload conditions. Background Technology

[0002] Pole-mounted vacuum circuit breakers are widely used switching devices in the distribution networks of the smart grid industry. Installed on outdoor utility poles, they are used for fault protection, sectional isolation, and control operations of distribution lines. When a pole-mounted vacuum circuit breaker performs a tripping operation, the moving and stationary contacts separate, generating an electric arc. The high temperature of the arc causes a large amount of metal vapor to evaporate from the contact surface. Existing technology typically includes a shielding cover inside the arc-extinguishing chamber to block and capture this metal vapor, preventing vapor deposition on the inner wall of the insulating housing and reducing the surface insulation strength.

[0003] However, not all metal vapor molecules condense after impacting the shield surface. Since the condensation coefficient of metal vapor molecules in a vacuum environment is typically between 0.3 and 0.9, a considerable proportion of vapor molecules bounce off with each impact. These bounced vapor molecules move randomly inside the arc-extinguishing chamber, with some returning to the contact surface and depositing, forming localized metal deposit spots. The microstructure and material composition of these deposit spots differ from the contact matrix. When the contacts are closed, the contact resistance at these spots differs from that of the matrix, leading to uneven current distribution and causing localized overheating. During the next opening, the overheated area preferentially attracts arc roots, and the concentrated arc further accelerates material evaporation and sputtering in this area, exacerbating the uneven erosion of the contact surface. This creates a positive feedback degradation process of spot expansion and arc concentration, ultimately shortening the contact's electrical life. Furthermore, during long-term operation, vapor condensation and deposition concentrate in a localized area facing the contact. In this area, the condensate layer continuously thickens, the surface temperature gradually increases, and the condensation coefficient decreases accordingly, leading to an accelerated decline in localized vapor capture capability with increasing operation frequency. Meanwhile, the area of ​​the shield away from the contact almost entirely fails to participate in vapor capture, resulting in low material utilization.

[0004] The aforementioned problems are particularly prominent in distribution networks under transient overload conditions, such as short-circuit fault interruption, automatic reclosing during faults, inrush current when an unloaded transformer is energized, and inrush current when capacitor banks are switched on. Under these conditions, the interrupting current far exceeds the rated value, the arc energy increases proportionally to the square of the current, and the amount of metal vapor evaporating from the contact surface is significantly higher than during normal interruption. Consequently, the vapor rebound also increases, significantly accelerating the formation and expansion of deposits on the contact surface. The arc-extinguishing chamber of a pole-mounted circuit breaker is a permanently sealed structure, and the contacts and shielding cannot be replaced or maintained during operation. The contact spot problem accumulates continuously with operation and cannot be alleviated. When pole-mounted vacuum circuit breakers are used under frequent overload conditions, the contact spot problem caused by metal vapor rebound is even more severe. Therefore, improving the overall service life is a crucial consideration. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a pole-mounted circuit breaker for transient overload conditions. Through a double-layer structure of an inner mesh and an outer cylindrical layer, metal vapor molecules collide multiple times between the two layers, successively consuming kinetic energy and increasing the condensation probability. This significantly reduces vapor rebound and minimizes the deposition of rebounded vapor on the contact surface, thereby inhibiting the formation and expansion of contact spots. The movable design ensures that vapor condensation and deposition are evenly distributed on the mesh surface, avoiding local saturation and extending the effective capture life of the shield.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A pole-mounted circuit breaker for instantaneous overload conditions includes a mechanism box, inside which is an operating mechanism and a movable plate that can move left and right. The operating mechanism can control the left and right movement of the movable plate. Three vacuum circuit breakers are installed at the upper end of the mechanism box, and a current transformer is installed on the rear side of each vacuum circuit breaker. The three contact opening and closing mechanisms include a stationary conductive rod fixedly installed on the top of the vacuum circuit breaker chamber, a stationary contact installed at the lower end of the stationary conductive rod, a movable connecting rod that can move up and down inside the vacuum circuit breaker chamber, a movable contact fixedly connected at the upper end of the movable connecting rod, and a lifting rod fixedly connected at the lower end of the movable connecting rod extending into the mechanism box. The lower end of the lifting rod is hinged to the moving plate through a swing arm. Three capture mechanisms are installed inside three vacuum circuit breaker chambers. Each capture mechanism includes an outer capture cylinder. The inner sides of the upper and lower ends of the outer capture cylinder are rotatably connected to support rings through support bearings. The two support rings are connected to the inner capture cylinder through two one-way bearings. The inner capture cylinder has multiple capture holes. The inner capture cylinder rotates through a rotating mechanism, and the outer capture cylinder moves up and down through a lifting mechanism.

[0007] Preferably, each of the three vacuum circuit breakers is equipped with an incoming terminal at its upper end, and each current transformer is equipped with an outgoing terminal at its rear. Each incoming terminal is electrically connected to a corresponding stationary conductive rod, and each outgoing terminal is electrically connected to a corresponding moving conductive rod.

[0008] Preferably, an aviation plug is installed on the front side of the mechanism box, and an operation feedback panel is installed on the front side of the mechanism box, the operation feedback panel cooperating with the operation mechanism.

[0009] Preferably, the operation feedback panel consists of a circuit breaker handle, an energy storage handle, a circuit breaker indicator head, and an energy storage indicator head.

[0010] Preferably, a shield is installed on the inner wall of each of the vacuum circuit breakers.

[0011] Preferably, a movable cylinder is fixedly connected to the outside of each of the movable poles, and a fixed ring is fixedly connected to the outside of each of the movable cylinders. Each fixed ring is fixedly connected to the inner bottom of the corresponding vacuum circuit breaker chamber through a bellows.

[0012] Preferably, the rotating mechanism includes multiple fixed frames fixedly connected to the bottom of the shield, with a fixed disk fixedly connected to the upper end of the multiple fixed frames. A rotating ring is rotatably connected to the middle of the fixed disk via a support bearing. Two connecting strips are fixedly connected to the outer side of the rotating ring, and an optical axis is fixedly connected to the upper end of each of the two connecting strips. Two L-shaped extension plates are symmetrically fixedly connected to the lower end of the inner capture tube. The two optical axes pass through the corresponding L-shaped extension plates and are slidably connected.

[0013] Preferably, the rotating mechanism further includes a spiral groove formed on the outside of the moving cylinder, the moving cylinder being located inside the rotating ring, and a sliding pin being fixedly connected to the inside of the rotating ring. The sliding pin extends into the spiral groove and is slidably connected to the inner wall of the spiral groove. When the moving cylinder moves up and down, the rotating ring can be rotated.

[0014] Preferably, the lifting mechanism includes a driven ring, the upper ends of both optical shafts are fixedly connected to the driven ring, multiple branch rods are fixedly connected to the inner side of the driven ring, and a connecting ring is fixedly connected to the inner side of the multiple branch rods. A rotating cylinder is installed on the inner side of the connecting ring through a one-way bearing. The rotating cylinder is sleeved on the outer side of the stationary conductive rod. A reciprocating threaded groove is provided on the outer side of the rotating cylinder. A lifting seat is installed on the reciprocating threaded groove of the rotating cylinder. As the rotating cylinder rotates in one direction, the lifting seat can move up and down reciprocally. The two sides of the lifting seat are fixedly connected to the outer capture cylinder through two L-shaped rods respectively.

[0015] Preferably, a connecting seat is fixedly connected to the upper end of the stationary contact, and two guide rods are symmetrically fixedly connected to the upper end of the connecting seat. The upper ends of the two guide rods pass through the lifting seat and are slidably connected.

[0016] Compared with the prior art, the beneficial effects of this invention are as follows: 1. The design adopts a double-layer structure with an inner perforated mesh cylinder and an outer closed cylinder. The sum of the surface areas of the inner mesh wire and the edges of the capture holes is much larger than that of a single-layer closed cylinder of the same size, which effectively increases the steam capture area per unit space and realizes the graded capture of steam.

[0017] 2. The annular gap between the double-layer cylinders creates a multiple collision confinement effect. The rebounding vapor molecules collide repeatedly within the gap. Each collision consumes kinetic energy and gains a new condensation opportunity, which greatly reduces the probability of vapor molecules escaping from the double-layer structure and returning to the contact surface, effectively inhibiting the formation of deposit spots on the contact surface.

[0018] 3. The inner layer rotates step by step during the opening and closing of the gate, causing the alignment position of the capture hole to change periodically. The deposition position of the vapor penetrating the inner layer on the inner wall of the outer cylinder shifts in a ring shape accordingly, avoiding excessive local condensation layer thickness in the outer cylinder and achieving uniform utilization of the entire inner wall of the outer cylinder.

[0019] 4. The inner and outer layers reciprocate up and down during the opening and closing operations, allowing different height areas to alternately target the vapor diffusion concentration area of ​​the contact head, avoiding localized vapor accumulation along the height direction, and achieving effective utilization of the entire height direction of the outer layer cylinder. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of a pole-mounted circuit breaker for transient overload conditions proposed in this invention; Figure 2 for Figure 1 A view from the left side; Figure 3 for Figure 1 Cross-sectional view; Figure 4 This is a cross-sectional view of one of the vacuum circuit breakers and its internal structure. Figure 5 for Figure 4 Front plan view; Figure 6 for Figure 4 Schematic diagram after removing the vacuum circuit breaker chamber and shielding cover; Figure 7 for Figure 6 A cross-sectional schematic diagram; Figure 8 for Figure 7 Enlarged view of point A.

[0021] In the diagram: 1. Mechanism box, 2. Vacuum circuit breaker chamber, 3. Incoming terminal, 4. Operation feedback panel, 5. Outgoing terminal, 6. Moving plate, 7. Lifting rod, 8. Swing arm, 9. Moving contact rod, 10. Shielding cover, 11. Operating mechanism, 12. Moving contact, 13. Static conductive rod, 14. Static contact, 15. Moving cylinder, 16. Fixing ring, 17. Bellows, 18. Aviation plug, 19. Outer capture cylinder, 20. Inner capture cylinder, 21. Support ring, 22. Spiral groove, 23. Fixing plate, 24. Fixing frame, 25. Rotating ring, 26. Connecting bar, 27. Optical axis, 28. L-shaped extension plate, 29. Driven ring, 30. Rotating cylinder, 31. Reciprocating threaded groove, 32. Lifting seat, 33. L-shaped rod, 34. Branch rod, 35. Guide rod, 36. Connecting seat, 37. Current transformer. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0023] The pole-mounted circuit breaker of this invention is a part of electrical switches and is a basic power component for control and protection in power systems. It can be applied in distribution networks containing power electronic components (such as photovoltaic inverters, energy storage converters, SVG, etc.). The pole-mounted circuit breaker can serve as the upper-level protection of the grid connection point and disconnect the line in the event of a system-level fault. As a basic core device for smart distribution network protection in the smart grid industry, the pole-mounted circuit breaker is one of the core basic safety conditions for the large-scale grid connection of new energy. This solution effectively improves the overall service life of the contacts through a rotatable and movable double-layer capture structure.

[0024] Reference Figures 1-8 A pole-mounted circuit breaker for instantaneous overload conditions includes a mechanism box 1, which serves as the basic support housing for the entire circuit breaker and is used to house and protect the internal functional components. The mechanism box 1 contains an operating mechanism 11 and a movable plate 6 that can move left and right. The operating mechanism 11 provides the mechanical driving force required for opening and closing actions. The operating mechanism 11 can control the left and right movement of the movable plate 6. Specifically, the operating mechanism 11 includes structures such as an energy storage spring, a trip unit, and a transmission assembly. The energy storage spring is used to store mechanical energy in advance and release the energy when the opening and closing command is triggered. The trip unit is used to trigger the release of the energy storage spring under the drive of the protection signal. The transmission assembly is used to convert the energy released by the energy storage spring into the horizontal movement of the movable plate 6. The specific structure and working principle of the operating mechanism 11 are existing technologies, and it has two operating modes: manual and electric drive, which will not be described in detail here. The movable plate 6, acting as an intermediate input component for motion conversion, transmits the horizontal motion output from the operating mechanism 11 to the contact opening and closing mechanism. Three vacuum circuit breaker chambers 2 are installed at the upper end of the mechanism box 1, arranged in a straight line. Their interiors are maintained in a sealed high-vacuum state, providing an arc-extinguishing environment for the generation and extinction of the electric arc. A shielding cover 10 is installed on the inner wall of each vacuum circuit breaker chamber 2 to shield against arc radiation and metal vapor sputtering generated during the arc extinguishing process, preventing them from directly impacting the inner wall of the vacuum circuit breaker chamber 2. A current transformer 37 is installed on the rear side of each vacuum circuit breaker chamber 2, used to collect real-time data on the power distribution line's electrical current. The current signal is transmitted to the protection device to realize the overcurrent protection and short circuit protection functions. The upper end of each of the three vacuum circuit breakers 2 is equipped with an incoming terminal 3. The incoming terminal 3 is used to connect the power supply side conductor of the overhead power distribution line. The rear side of each current transformer 37 is equipped with an outgoing terminal 5. The outgoing terminal 5 is used to connect the load side conductor. Each incoming terminal 3 is electrically connected to the corresponding stationary conductive rod 13. The stationary conductive rod 13 is a fixed conductive path that guides the current of the incoming terminal 3 to the stationary contact 14. Each outgoing terminal 5 is electrically connected to the corresponding moving contact rod 9. The moving contact rod 9 is a conductive path that can move back and forth along the axial direction. Its lifting and lowering drives the contact to realize the opening and closing action. Each movable connecting rod 9 is fixedly connected to a movable cylinder 15 on its outer side. The movable cylinder 15 is sleeved on the outside of the movable connecting rod 9 and rises and falls synchronously with the movable connecting rod 9. The contact point between the two is sealed. Each movable cylinder 15 is fixedly connected to a fixing ring 16 on its outer side. Each fixing ring 16 is fixedly connected to the inner bottom of the corresponding vacuum circuit breaker chamber 2 through a bellows 17. The bellows 17 is an elastic sealing element that allows the movable connecting rod 9 to perform axial reciprocating movement while maintaining a vacuum seal, and at the same time isolates the external atmosphere from the vacuum environment inside the arc extinguishing chamber.

[0025] The front of the mechanism box 1 is equipped with an aviation plug 18, which is an external electrical interface for connecting external control power and signal cables to realize the electric opening and closing operation and remote control of the circuit breaker. The front of the mechanism box 1 is also equipped with an operation feedback panel 4, which consists of an opening / closing handle, an energy storage handle, an opening / closing indicator head, and an energy storage indicator head. The opening / closing handle is used to manually drive the circuit breaker to perform opening or closing operations. The energy storage handle is used to manually store energy in the spring of the operating mechanism 11. The opening / closing indicator head is used to indicate to the operation and maintenance personnel the current opening or closing status of the circuit breaker. The energy storage indicator head is used to indicate whether the spring of the operating mechanism 11 has reached the required energy storage level. All of the above are existing technologies and will not be described in detail here. The operation feedback panel 4 works in conjunction with the operating mechanism 11.

[0026] The system also includes three contact opening and closing mechanisms. Each mechanism includes a stationary conductive rod 13 fixedly installed at the top of the vacuum circuit breaker chamber 2, with a stationary contact 14 mounted at the lower end of the rod 13. Inside the vacuum circuit breaker chamber 2, a movable contact rod 9 is installed, with a movable contact 12 fixedly connected to the upper end of the rod 9. The stationary contact 14 is a fixed contact end face that works with the movable contact 12 to connect and disconnect the main circuit. When the movable contact 12 and the stationary contact 14 are closed, they form a low-resistance conductive path; when separated, they remain open. An electric arc is generated in the gap and extinguished in a high vacuum environment by the recovery of the medium when the current crosses zero. The lower end of the moving rod 9 extends into the mechanism box 1 and is fixedly connected to the lifting rod 7. The lower end of the lifting rod 7 is hinged to the moving plate 6 through the swing arm 8. One end of the swing arm 8 is hinged to the lifting rod 7 and the other end is hinged to the moving plate 6, forming a crank-connecting rod motion conversion structure (which belongs to the prior art), converting the horizontal movement of the moving plate 6 into the vertical movement of the lifting rod 7, thereby driving the moving contact 12 to open and close the circuit.

[0027] The system also includes three capture mechanisms, which are installed inside three vacuum circuit breaker chambers 2. Each capture mechanism includes an outer capture cylinder 19. The inner sides of the upper and lower ends of the outer capture cylinder 19 are rotatably connected to a support ring 21 via a support bearing. The support bearing provides low-friction rotational support for the rotational connection between the outer capture cylinder 19 and the support ring 21, allowing the support ring 21 to rotate freely relative to the outer capture cylinder 19. The two support rings 21 are connected to an inner capture cylinder 20 via two one-way bearings. The inner capture cylinder 20 is located inside the outer capture cylinder 19 and the two are arranged coaxially. An annular gap is formed between the outer wall of the inner capture cylinder 20 and the inner wall of the outer capture cylinder 19, forming a vapor capture space between the two layers. The inner capture cylinder 20 has multiple capture holes distributed along the circumference and axial direction of the inner capture cylinder 20, allowing some metal vapor molecules to pass through the inner capture cylinder 20 to reach the outer capture cylinder 19, thus achieving double-layer graded capture. By using the one-way bearing, it can be ensured that the inner capture cylinder 20 always rotates in one direction after the subsequent rotation mechanism is triggered. In the double-layer structure, the inner trapping cylinder 20 is a perforated mesh cylinder, while the outer trapping cylinder 19 is a closed cylinder without perforations. The sum of the surface areas of the mesh surface and the edges of the trapping holes in the inner trapping cylinder 20 is much larger than the inner surface area of ​​a single-layer closed cylinder of the same size, effectively increasing the vapor trapping area per unit space. When metal vapor molecules diffuse outward from the contact area, they first collide with the mesh surface and the edges of the trapping holes in the inner trapping cylinder 20. Some vapor molecules condense directly on the surface of the inner trapping cylinder 20 after the collision and are captured for the first time, while other vapor molecules pass through the trapping holes and enter the annular gap between the inner trapping cylinder 20 and the outer trapping cylinder 19, where they collide with the inner wall of the outer trapping cylinder 19 and condense for secondary capture.

[0028] Since the condensation coefficient of metal vapor molecules in a vacuum environment is typically between 0.3 and 0.9, a considerable proportion of molecules bounce off after each collision without condensing. In a single-layer shield structure, the bounced vapor molecules return directly to the internal space of the arc-extinguishing chamber, and some of them can return to the contact surface to deposit and form spots. In the double-layer structure of this scheme, most of the vapor molecules bouncing off the surface of the inner trapping cylinder 20 move towards the annular gap and collide with the inner wall of the outer trapping cylinder 19, while the vapor molecules bouncing off the inner wall of the outer trapping cylinder 19 bounce back to the mesh surface of the inner trapping cylinder 20. A multi-collision confinement effect similar to a blackbody cavity is formed between the two layers, causing the vapor molecules to bounce repeatedly between the two layers. Each bounce consumes kinetic energy and gains a new condensation opportunity. The cumulative capture probability approaches 1 with the increase of the number of collisions, thereby significantly reducing the probability of vapor molecules escaping from the double-layer structure and returning to the contact surface, effectively suppressing the formation of deposited spots on the contact surface.

[0029] The inner capture cylinder 20 rotates via a rotating mechanism, which includes multiple fixed frames 24 fixedly connected to the bottom of the shield 10. The upper ends of the multiple fixed frames 24 are all fixedly connected to a fixed disk 23. A rotating ring 25 is rotatably connected to the middle of the fixed disk 23 via a second support bearing. The second support bearing allows the rotating ring 25 to rotate freely around the axis on the fixed disk 23. Two connecting strips 26 are fixedly connected to the outer side of the rotating ring 25. The upper ends of the two connecting strips 26 are fixedly connected to optical shafts 27. The optical shafts 27 provide guidance and a carrier for motion transmission for the subsequent lifting mechanism. Two L-shaped extension plates 28 are symmetrically fixedly connected to the lower end of the inner capture cylinder 20. The two optical shafts 27 pass through the corresponding L-shaped extension plates 28 and are slidably connected. The L-shaped extension plates 28 transmit the rotational motion of the optical shafts 27 to the inner capture cylinder 20, causing the inner capture cylinder 20 to rotate accordingly. At the same time, the sliding fit between the optical shafts 27 and the L-shaped extension plates 28 allows the inner capture cylinder 20 to have the freedom of axial lifting during rotation. Furthermore, the rotating mechanism also includes a spiral groove 22 formed on the outside of the moving cylinder 15. The spiral groove 22 is a spiral groove structure used to convert the axial lifting motion of the moving cylinder 15 into the circumferential rotation motion of the rotating ring 25. The moving cylinder 15 is located inside the rotating ring 25. A sliding pin 38 is fixedly connected to the inner side of the rotating ring 25. The sliding pin 38 extends into the spiral groove 22 and is slidably connected to the inner wall of the spiral groove 22. When the moving cylinder 15 moves up and down, the rotating ring 25 can be rotated, that is, the sliding pin 38 is embedded in the spiral groove 22. When the moving cylinder 15 moves up and down, the side wall of the spiral groove 22 applies a circumferential thrust to the sliding pin 38, driving the rotating ring 25 to rotate around the axis. Thus, the lifting motion of the moving contact rod 9 in each opening and closing operation of the circuit breaker is automatically converted into the rotation of the inner capture cylinder 20. In conjunction with the one-way bearing, it is ensured that it can only rotate in one direction, realizing the intermittent angle adjustment of the inner capture cylinder 20.

[0030] It should be noted that the process of metal vapor being generated from the contacts, diffusing to the surface of the shield, and condensing during a single opening and closing operation is extremely rapid, with a timescale on the order of microseconds to milliseconds. The rotation of the inner capture cylinder 20 cannot and does not need to occur simultaneously during the single vapor diffusion process. The rotation of the inner capture cylinder 20 mainly occurs during the interval between two opening operations, driven by the lifting and lowering motion of the moving contact rod 9 through the spiral groove 22 of the moving cylinder 15. After each opening and closing operation is completed, the inner capture cylinder 20 rotates by a set angle in steps.

[0031] The position of the capture holes on the inner capture cylinder 20 changes with rotation. Vapor molecules not intercepted by the mesh of the inner capture cylinder 20 pass through the capture holes and deposit at an angle shift on the inner wall of the outer capture cylinder 19. If the inner capture cylinder 20 does not rotate, vapor passing through the fixed capture holes in each operation will always deposit in the same area on the inner wall of the outer capture cylinder 19, causing the condensate layer in that area to thicken rapidly while other areas hardly participate in capture, significantly reducing the effective utilization area of ​​the outer capture cylinder 19. After each step rotation of the inner capture cylinder 20, the capture holes align with different angle areas on the inner wall of the outer capture cylinder 19, causing the landing point of the penetrating vapor to shift in the next operation. After multiple operations, the entire inner circumference of the outer capture cylinder 19 is utilized sequentially, and the vapor condensation and deposition on the inner wall are evenly distributed, avoiding excessively thick local condensate layers that would reduce the condensation coefficient. This fully utilizes the capture capacity of the outer capture cylinder 19 and extends the overall service life of the capture mechanism.

[0032] The outer capture cylinder 19 moves up and down via a lifting mechanism, which includes a driven ring 29. The upper ends of the two optical shafts 27 are fixedly connected to the driven ring 29. The driven ring 29 collects and transmits the rotational motion of the two optical shafts 27 to the transmission component of the lifting mechanism. Multiple branch rods 34 are fixedly connected to the inner side of the driven ring 29, and a connecting ring is fixedly connected to the inner side of the multiple branch rods 34. A rotating cylinder 30 is installed on the inner side of the connecting ring via a one-way bearing. The one-way bearing is existing technology, and its function is to allow the rotating cylinder 30 to rotate in only one direction and lock it in the opposite direction, thereby converting the bidirectional rotation transmitted from the optical shafts 27 into the unidirectional intermittent rotation of the rotating cylinder 30. This allows the lifting mechanism to drive the outer capture cylinder 19 to adjust all positions within the adjustable range. The rotating cylinder 30 is sleeved on the outside of the stationary conductive rod 13, and a reciprocating thread groove 31 is provided on the outside of the rotating cylinder 30. The reciprocating thread groove 31 is an alternating spiral. The grooved structure allows the lifting seat 32 to reciprocate up and down during the continuous unidirectional rotation of the rotating cylinder 30. The lifting seat 32 is installed on the reciprocating threaded groove 31 of the rotating cylinder 30. As the rotating cylinder 30 rotates in one direction, the lifting seat 32 can reciprocate up and down. This connection method is existing technology, that is, the lifting seat 32 is provided with corresponding sliding teeth inside, which can cooperate with the reciprocating threaded groove 31. The two sides of the lifting seat 32 are fixedly connected to the outer capture cylinder 19 through two L-shaped rods 33 respectively. The upper end of the stationary contact 14 is fixedly connected to the connecting seat 36. The intermittent reciprocating rotation of the outer capture cylinder 19 allows its different height areas to participate in steam capture in turn, that is, to change the local area facing the contact direction (i.e., the local horizontal area near the moving contact 12 and the stationary contact 14, which is the area where steam diffusion is concentrated during opening and closing), avoiding the situation where steam condenses and accumulates in a local area, causing the local area to continuously thicken and the capture capacity to decrease rapidly. This improves the overall material utilization rate. Two guide rods 35 are symmetrically fixedly connected to the upper end of the connecting seat 36. The upper ends of the two guide rods 35 pass through the lifting seat 32 and are slidably connected. The guide rods 35 guide and constrain the movement of the lifting seat 32 to prevent the lifting seat 32 from deflecting or radially shifting during reciprocating motion, thus ensuring the accuracy and stability of the lifting motion of the outer capture cylinder 19.

[0033] It is worth mentioning that this solution is applicable to pole-mounted circuit breakers with a rated voltage of [value missing]. At this voltage level, the electric field strength inside the arc-extinguishing chamber is low, eliminating the need for electric field equalization maintenance via the shield 10. The design of the shield 10 and the capture mechanism can be fully focused on the efficient capture of metal vapor. Furthermore, all rotating and sliding contact parts in this solution, including the sliding contact surfaces of support bearing 1, support bearing 2, one-way bearing 1, one-way bearing 2, the optical shaft 27 and the L-shaped extension plate 28, the contact surface of the sliding pin 38 inside the rotating ring 25 and the spiral groove 22, the sliding contact surface of the lifting seat 32 and the guide rod 35, and the contact surface of the rotating cylinder 30 and the reciprocating thread groove 31, are all surface-hardened (nitrided) to suppress microparticles generated by friction during long-term operation, preventing microparticles from diffusing and depositing on the inner surface of the contacts or insulating housing in a vacuum environment, thus ensuring the long-term stability of the cleanliness and insulation performance inside the arc-extinguishing chamber.

[0034] In this invention, the operating mechanism 11 inside the mechanism box 1 stores mechanical energy in advance through an energy storage spring. Energy storage can be completed via a manual energy storage handle or electric control, and the energy storage status is displayed by the energy storage indicator on the operation feedback panel 4. After the opening / closing command is triggered, the trip unit unlocks the energy storage spring, and the elastic potential energy is converted into a horizontal driving force through the transmission component, driving the moving plate 6 to move horizontally left and right. Maintenance personnel can manually operate the opening / closing mechanism via the opening / closing handle on the operation feedback panel 4, and the equipment's operating status is fed back in real time by the opening / closing indicator.

[0035] The horizontal movement of the moving plate 6 is converted into vertical lifting power through the crank-connecting rod structure composed of the swing arm 8 and the lifting rod 7, which drives the moving contact rod 9 to reciprocate up and down along the axial direction, so that the moving contact 12 at the top of the moving contact rod 9 and the stationary contact 14 at the bottom of the stationary contact rod 13 can complete the closing and separation, realizing the core action of the circuit breaker closing and opening. The three vacuum circuit breakers 2, arranged in a straight line, maintain a high vacuum environment. The electric arc generated at the moment the contacts open can be quickly extinguished by the vacuum medium when the current crosses zero, thus achieving arc extinguishing protection. The shielding cover 10 on the inner wall of the vacuum circuit breaker 2 can shield the arc radiation and metal vapor sputtering during the arc extinguishing process, preventing damage to the inner wall of the circuit breaker.

[0036] During the opening and closing process, the movable cylinder 15 fixed on the outside of the moving contact pole 9 rises and falls synchronously with it. The fixed ring 16 on the outside of the movable cylinder 15 is connected to the bottom of the vacuum circuit breaker chamber 2 through the bellows 17. By utilizing the elastic sealing characteristics of the bellows 17, the external atmosphere is isolated while ensuring the freedom of the moving contact pole 9 to rise and fall, and the vacuum sealing environment inside the vacuum circuit breaker chamber 2 is continuously maintained.

[0037] During each opening and closing operation, the moving contact pole 9 drives the moving cylinder 15 to rise and fall. The spiral groove 22 on the outside of the moving cylinder 15 presses the sliding pin 38 on the inside of the rotating ring 25 through the groove wall, converting the axial lifting motion into the circumferential rotation of the rotating ring 25.

[0038] The rotating ring 25 is fixed to the optical axis 27 via the outer connecting strip 26 and slides with the L-shaped extension plate 28 at the bottom of the inner capture cylinder 20. This allows the rotational power of the rotating ring 25 to be transmitted to the inner capture cylinder 20. With the help of the one-way bearing, the inner capture cylinder 20 can achieve intermittent fixed rotation. That is, after each opening and closing operation, the inner capture cylinder 20 rotates by a fixed angle, changing the alignment position of the capture hole. This causes the deposition position of metal vapor on the inner wall of the outer capture cylinder 19 to shift in a ring shape, achieving uniform utilization of the entire inner wall of the outer capture cylinder 19 and avoiding excessive local condensation layer that would reduce the capture capacity.

[0039] The upper end of the optical axis 27 is connected to the driven ring 29. The driven ring 29 is connected to the rotating cylinder 30 outside the stationary conductive rod 13 through the branch rod 34, the connecting ring and the one-way bearing 2. The one-way bearing 2 converts the rotational motion of the inner driven ring 29 into the one-way intermittent rotation of the rotating cylinder 30.

[0040] The reciprocating threaded groove 31 on the outer side of the rotating cylinder 30 engages with the lifting seat 32. The unidirectional rotating cylinder 30 drives the lifting seat 32 to perform reciprocating linear motion along the guide rod 35. The guide rod 35 precisely guides the lifting seat 32 to prevent radial deviation. The lifting seat 32 drives the outer capturing cylinder 19 to synchronously and intermittently rise and fall via the L-shaped rod 33. This allows different height areas of the outer capturing cylinder 19 to alternately target the vapor diffusion concentration area of ​​the contact head, avoiding localized vapor accumulation and achieving effective utilization of the entire height range. This improves the overall service life of the capturing mechanism and the arc extinguishing stability under instantaneous overload conditions.

[0041] It should be noted that the capture mechanism adopts an inner and outer double-layer cylinder structure. The outer capture cylinder 19 is rotatably engaged with the support ring 21 through upper and lower support bearings. The inner capture cylinder 20 is fixed between the support rings 21. The two are arranged coaxially and form an annular vapor capture gap. The inner capture cylinder 20 has a perforated mesh structure. Its surface and capture holes can perform initial collision condensation capture of the metal vapor generated by the arc extinguishing of the contacts. Vapor molecules that are not captured pass through the capture holes, enter the double-layer cylinder gap, and collide with the sealed inner wall of the outer capture cylinder 19 to complete secondary condensation capture, increasing the actual capture area. The gap between the double-layer cylinders can create a multiple collision trapping effect, causing the rebounding vapor molecules to collide repeatedly within the gap, continuously increasing the probability of vapor condensation and capture, significantly reducing the return of metal vapor to the contact area for deposition, avoiding the formation of deposition spots on the contact surface, and ensuring stable contact conductivity and opening / closing performance.

[0042] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A pole-mounted circuit breaker for transient overload conditions, characterized in that, include: The mechanism box (1) is equipped with an operating mechanism (11) and a movable plate (6) that can move left and right. The operating mechanism (11) can control the movable plate (6) to move left and right. Three vacuum circuit breakers (2) are installed at the upper end of the mechanism box (1). A current transformer (37) is installed on the rear side of each vacuum circuit breaker (2). Three contact opening and closing mechanisms, the contact opening and closing mechanisms include a stationary conductive rod (13) fixedly installed at the top of the vacuum circuit breaker chamber (2), a stationary contact (14) installed at the lower end of the stationary conductive rod (13), a movable connecting rod (9) that can move up and down is provided inside the vacuum circuit breaker chamber (2), a movable contact (12) is fixedly connected at the upper end of the movable connecting rod (9), the lower end of the movable connecting rod (9) extends into the mechanism box (1) and is fixedly connected to a lifting rod (7), the lower end of the lifting rod (7) is hinged to the moving plate (6) through a swing arm (8); Three capture mechanisms are installed inside three vacuum circuit breakers (2). Each capture mechanism includes an outer capture cylinder (19). The inner sides of the upper and lower ends of the outer capture cylinder (19) are rotatably connected to a support ring (21) through a support bearing. The two support rings (21) are connected to an inner capture cylinder (20) through two one-way bearings. The inner capture cylinder (20) has multiple capture holes. The inner capture cylinder (20) rotates through a rotating mechanism. The outer capture cylinder (19) moves up and down through a lifting mechanism.

2. A pole-mounted circuit breaker for transient overload conditions according to claim 1, characterized in that, Each of the three vacuum circuit breakers (2) is equipped with an incoming terminal (3) at its upper end, and each current transformer (37) is equipped with an outgoing terminal (5) on its rear side. Each incoming terminal (3) is electrically connected to the corresponding static conductive rod (13), and each outgoing terminal (5) is electrically connected to the corresponding dynamic conductive rod (9).

3. A pole-mounted circuit breaker for transient overload conditions according to claim 1, characterized in that, The front side of the mechanism box (1) is equipped with a flight plug (18) and an operation feedback panel (4) is installed on the front side of the mechanism box (1). The operation feedback panel (4) cooperates with the operation mechanism (11).

4. A pole-mounted circuit breaker for transient overload conditions according to claim 3, characterized in that, The operation feedback panel (4) consists of a circuit breaker handle, an energy storage handle, a circuit breaker indicator head, and an energy storage indicator head.

5. A pole-mounted circuit breaker for transient overload conditions according to claim 1, characterized in that, Each of the vacuum circuit breakers (2) has a shield (10) installed on its inner wall.

6. A pole-mounted circuit breaker for transient overload conditions according to claim 1, characterized in that, Each of the moving poles (9) is fixedly connected to a movable cylinder (15) on its outer side, and each movable cylinder (15) is fixedly connected to a fixed ring (16) on its outer side. Each fixed ring (16) is fixedly connected to the inner bottom of the corresponding vacuum circuit breaker chamber (2) through a bellows (17).

7. A pole-mounted circuit breaker for transient overload conditions according to claim 1, characterized in that, The rotating mechanism includes multiple fixed frames (24) fixedly connected to the bottom of the shield (10). The upper ends of the multiple fixed frames (24) are fixedly connected to a fixed disk (23). The middle part of the fixed disk (23) is rotatably connected to a rotating ring (25) through a support bearing. Two connecting strips (26) are fixedly connected to the outer side of the rotating ring (25). The upper ends of the two connecting strips (26) are fixedly connected to optical axes (27). The lower end of the inner capture tube (20) is symmetrically fixedly connected to two L-shaped extension plates (28). The two optical axes (27) pass through the corresponding L-shaped extension plates (28) and are slidably connected.

8. A pole-mounted circuit breaker for transient overload conditions according to claim 7, characterized in that, The rotating mechanism also includes a spiral groove (22) opened on the outside of the moving cylinder (15). The moving cylinder (15) is located inside the rotating ring (25). A sliding pin (38) is fixedly connected to the inside of the rotating ring (25). The sliding pin (38) extends into the spiral groove (22) and slides in connection with the inner wall of the spiral groove (22). When the moving cylinder (15) moves up and down, the rotating ring (25) can rotate.

9. A pole-mounted circuit breaker for transient overload conditions according to claim 8, characterized in that, The lifting mechanism includes a driven ring (29), the upper ends of two optical shafts (27) are fixedly connected to the driven ring (29), a number of branch rods (34) are fixedly connected to the inner side of the driven ring (29), a connecting ring is fixedly connected to the inner side of the multiple branch rods (34), a rotating cylinder (30) is installed on the inner side of the connecting ring through a one-way bearing, the rotating cylinder (30) is sleeved on the outer side of the static conductive rod (13), a reciprocating thread groove (31) is provided on the outer side of the rotating cylinder (30), a lifting seat (32) is installed on the reciprocating thread groove (31) of the rotating cylinder (30), as the rotating cylinder (30) rotates in one direction, the lifting seat (32) can move up and down reciprocally, and the two sides of the lifting seat (32) are fixedly connected to the outer capture cylinder (19) through two L-shaped rods (33).

10. A pole-mounted circuit breaker for transient overload conditions according to claim 9, characterized in that, The upper end of the stationary contact (14) is fixedly connected to a connecting seat (36), and the upper end of the connecting seat (36) is symmetrically fixedly connected to two guide rods (35). The upper ends of the two guide rods (35) pass through the lifting seat (32) and are slidably connected.

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