A high breaking capacity frame circuit breaker

Abstract

This utility model discloses a high breaking capacity frame circuit breaker, including an arc-extinguishing structure, a stationary contact assembly, and a moving contact assembly disposed in the housing. The arc-extinguishing structure includes an arc-extinguishing chamber and an arc-extinguishing cavity, with first and second arc-extinguishing chambers spaced apart inside the arc-extinguishing chamber. The stationary contact assembly includes a main stationary contact and two sets of arc-initiating stationary contacts. The moving contact assembly includes multiple active contacts corresponding to the main stationary contacts, and two sets of arc-initiating moving contacts spaced apart between the active contacts. The two sets of arc-initiating moving contacts extend into the openings of their respective arc-extinguishing cavities and cooperate with the arc-initiating stationary contacts. This technical solution, by setting a double arc-extinguishing cavity in the arc-extinguishing chamber and matching it with two sets of arc-extinguishing plate assemblies, and by cooperating with the double arc-extinguishing cavity and the double arc-initiating moving contacts, significantly increases the number of arc-extinguishing plates, improves arc voltage and heat dissipation capacity, realizes dual-path diversion of arc energy, effectively prevents arc reignition, and significantly improves breaking capacity and electrical life.

Description

Technical Field

[0001] This utility model relates to the field of low-voltage electrical technology, specifically to a high breaking capacity frame circuit breaker. Background Technology

[0002] A frame-type circuit breaker is a switching device capable of connecting, carrying, and breaking current under normal circuit conditions, and also capable of connecting, carrying, and breaking current for a certain time under specified abnormal circuit conditions. In a frame-type circuit breaker, an arc-extinguishing chamber is typically installed inside to extinguish the electric arc generated by the contacts in the electrical equipment, ensuring the safe operation of the equipment. However, when breaking short-circuit currents, the breaking capacity of existing circuit breakers is often limited due to severe contact erosion of the moving contacts and the inability of the electric arc to enter the arc-extinguishing chamber's grid plates in a timely and sufficient manner. Currently, each phase circuit of a frame-type circuit breaker typically has only one set of arc-extinguishing grid plates installed in the arc-extinguishing chamber. An electromagnetic force is generated in the current path by an arc-initiating plate, which facilitates the movement of the arc towards the arc-extinguishing chamber. Conventional methods to improve breaking capacity include increasing the contact gap and adding arc-initiating plates, but due to the limitations of the existing arc-extinguishing chamber structure, the improvement in arc-extinguishing capacity is limited.

[0003] With the continuous expansion of power system capacity, existing arc extinguishing structures also have the following problems when dealing with large-capacity short-circuit currents: First, an electric arc is generated between the moving and stationary contacts of the circuit breaker due to the breaking process. However, the space of the arc extinguishing chamber in the traditional layout is limited, and the number of arc extinguishing plates that can be installed is small. This results in each arc extinguishing plate bearing a large arc voltage. The larger the arc voltage, the more difficult it is to extinguish the arc, which can easily cause the arc to reignite, posing a great danger and affecting the breaking capacity and service life of the circuit breaker. Second, the generated arc is blown or pulled into the arc extinguishing chamber by electromagnetic force and the action of the arc ignition plate. This process is delayed and unstable. This makes the process of the arc root peeling off from the contact surface and transferring to the arc extinguishing chamber delayed. The longer the arc stays on the moving and stationary contacts, the more severe the contact erosion, which directly reduces the conductivity and mechanical life of the contacts. Utility Model Content

[0004] Therefore, the technical problem to be solved by this utility model is to overcome the problem that the arc-extinguishing chamber space of the traditional layout of the frame circuit breaker in the prior art is limited, the number of arc-extinguishing plates that can be installed is small, the arc-extinguishing capacity is insufficient, and the breaking capacity and service life of the circuit breaker are affected.

[0005] To solve the above-mentioned technical problems, this utility model provides a high breaking capacity frame circuit breaker, including a housing and a contact system, an arc extinguishing structure, and an operating mechanism disposed within the housing:

[0006] The arc extinguishing structure includes an arc extinguishing chamber and two arc extinguishing cavities spaced apart within the arc extinguishing chamber, as well as an arc extinguishing chamber connected to the rear ends of the two arc extinguishing cavities. Arc extinguishing plate assemblies are respectively provided in the two arc extinguishing cavities.

[0007] The contact system includes a moving contact assembly and a stationary contact assembly. The stationary contact assembly includes a main stationary contact and two sets of arc-inducing stationary contacts electrically connected to the main stationary contact. The main stationary contact is located outside the openings of the two arc-extinguishing cavities, and the two sets of arc-inducing stationary contacts are respectively arranged at the bottom of the openings at the front ends of the two arc-extinguishing cavities. The moving contact assembly includes multiple active contacts corresponding to the main stationary contact, and two sets of arc-inducing moving contacts spaced apart between the multiple active contacts. The length of the two sets of arc-inducing moving contacts is greater than the length of the active contacts, and they extend into the openings of the two arc-extinguishing cavities to engage with the corresponding two sets of arc-inducing stationary contacts.

[0008] During the circuit breaker tripping process, multiple active contacts separate from the corresponding main stationary contacts before the two sets of arc-inducing moving contacts, and then the two sets of arc-inducing moving contacts separate from the corresponding two sets of arc-inducing stationary contacts.

[0009] As a preferred embodiment, the two arc-extinguishing chambers are respectively the first arc-extinguishing chamber and the second arc-extinguishing chamber, which are arranged side by side and separated, and together form an integrated double arc-extinguishing chamber structure. The arc-extinguishing plate assembly includes multiple arc-extinguishing grid plates arranged in parallel and spaced apart in each set of arc-extinguishing chambers.

[0010] As a preferred embodiment, a first arc-inducing plate is correspondingly provided in both the first and second arc-extinguishing cavities; the first arc-inducing plate is arranged on the top of the arc-extinguishing plate assembly, and the first arc-inducing plate has a bent arc-inducing end extending out of the arc-extinguishing cavity, which is positioned close to the opening and closing trajectory of the active contact.

[0011] As a preferred embodiment, the main stationary contact is fixedly mounted on the outgoing busbar, and the two sets of arc-inducing stationary contacts are respectively mounted on the connecting busbar, with the two sets of arc-inducing stationary contacts and the main stationary contact arranged parallel to each other along the direction of multiple active contacts; the connecting busbar is fixedly connected to or integrally formed with the outgoing busbar to realize the electrical connection between the arc-inducing stationary contact and the main stationary contact.

[0012] As a preferred embodiment, each of the arc-extinguishing cavities is further provided with a second arc-initiating plate, which is located at the bottom of the arc-extinguishing plate assembly of the corresponding arc-extinguishing cavity; one end of the second arc-initiating plate extends and is fixedly connected to the connecting bar or the arc-initiating stationary contact, and the other end extends into the corresponding arc-extinguishing cavity along the arc-entry direction of the arc-extinguishing cavity.

[0013] As a preferred embodiment, the middle part of the second arc-inducing plate is integrally bent to form a bent arc-inducing angle; the bent arc-inducing angle has two arc-inducing inclined surfaces set at a preset angle, one of which is in contact with the end inclined surface of the connecting row; the other arc-inducing inclined surface extends toward the side of the arc-extinguishing plate assembly in the corresponding arc-extinguishing cavity.

[0014] As a preferred embodiment, the connecting busbar is provided with an insulating gas-generating pad, which surrounds the outside of the arc-initiating stationary contact and covers the exposed conductive surfaces of the connecting busbar and the outgoing busbar.

[0015] As a preferred embodiment, each set of arc-initiating stationary contacts is provided with a magnetic blower at its bottom. The magnetic blower is used to generate a strong magnetic blowing force when the contacts break to quickly blow the arc into the gap of the arc-extinguishing grid plate in the corresponding arc-extinguishing cavity. The magnetic blower is composed of multiple permanent magnets stacked in the same direction and fixed between the bottom of the arc-initiating stationary contact and the second arc-initiating plate, and the magnetic field directions of the multiple permanent magnets are arranged in the same direction.

[0016] As a preferred embodiment, the moving contact assembly includes a contact frame rotatably mounted on the housing, wherein both the active contact and the arc-initiating moving contact are mounted on the contact frame; an insulating partition is provided on the side of the contact frame facing the outgoing busbar, the insulating partition extending and arranged opposite to the side wall of the main stationary contact and the outgoing busbar, such that the insulating partition rotates and abuts against one side wall of the outgoing busbar when the moving contact assembly and the stationary contact assembly are separated.

[0017] As a preferred embodiment, the arc-extinguishing chamber includes an arc-extinguishing cover, multiple arc-extinguishing plates, and an arc-extinguishing cavity; the arc-extinguishing cover is fixedly connected to the rear end of the arc-extinguishing chamber and encloses a closed cavity forming the arc-extinguishing cavity, which is connected to both the first and second arc-extinguishing cavities; the multiple arc-extinguishing plates are arranged parallel to each other and spaced apart within the arc-extinguishing cavity along a direction perpendicular to the arc-extinguishing grid plates; each arc-extinguishing plate has several arc-extinguishing holes, and the rear side plate of the arc-extinguishing cover, which is opposite to the arc-extinguishing plates, has several exhaust holes.

[0018] Compared with the prior art, the technical solution of this utility model has the following advantages:

[0019] 1. The high breaking capacity frame circuit breaker provided by this utility model, by setting up double arc-extinguishing chambers and matching two sets of arc-extinguishing plate assemblies in the arc-extinguishing chamber body, significantly expands the arc-extinguishing arrangement space and increases the number of arc-extinguishing plates. This can fully cut segmented arcs and enhance the near-cathode arc-extinguishing effect. After the arc is extinguished and cooled by the double arc-extinguishing chambers, it still needs to pass through the arc-extinguishing chamber body for secondary arc-extinguishing purification to remove residual arcs and high-temperature plasma, prevent the re-ignition caused by weak residual arcs, and efficiently conduct and dissipate arc heat. This design significantly increases the overall capacity of the arc-extinguishing chamber, enabling reliable interruption of higher-level large currents. At the same time, relying on the double arc-extinguishing chambers and two sets of arc-igniting moving contacts to form independent arc-ignition paths, the arc energy is evenly distributed. Parallel arc extinguishing in two arc-extinguishing chambers avoids overload or pressure imbalance in a single chamber, enabling arc diversion and dispersion, dispersing arc thermal shock and electrical stress, significantly shortening arc extinguishing time, and reducing the ablation degree of each pair of arc-initiating moving contacts. This ensures stable and rapid arc introduction into the arc-extinguishing chamber for arc extinguishing, effectively addressing the shortcomings of insufficient breaking capacity in traditional arc-extinguishing chambers. Furthermore, this technical solution employs a breaking sequence where the active contacts separate first and the arc-initiating moving contacts separate later, completely transferring the arc to the arc-initiating moving contact area, protecting the active contacts from arc ablation, effectively extending the service life of the entire circuit breaker, core contacts, and arc-extinguishing structure, and improving the overall arc extinguishing efficiency and ultimate short-circuit breaking capacity of the circuit breaker.

[0020] 2. In the high breaking capacity frame circuit breaker provided by this utility model, a second arc-inducing plate is set at the bottom of each group of arc-extinguishing chambers. The second arc-inducing plate is bent to form a bend arc-inducing angle with double arc-inducing slopes. The arc-inducing guide effect of the double arc-inducing slopes of the second arc-inducing plate changes the initial movement direction of the arc. Combined with the electric field concentration effect at the bend, the arc generated by the arc-inducing stationary contact is quickly guided along the slope into the arc-extinguishing grid area inside the arc-extinguishing chamber. This greatly shortens the movement path of the arc from the contact to the arc-extinguishing grid, reduces the residence time of the arc in the arc-inducing stationary contact area, thereby reducing the erosion loss of the arc-inducing stationary contact and greatly improving the overall breaking performance and service life of the circuit breaker.

[0021] 3. In the high breaking capacity frame circuit breaker provided by this utility model, the first and second arc-initiating plates are respectively arranged on the top and bottom of each arc-extinguishing cavity to form an enclosed arc-initiating structure, which avoids arc deflection and escape, and ensures that the arc enters the arc-extinguishing cavity for extinguishing. Combined with the independent arc-initiating design between the two sets of arc-initiating moving contacts and the double arc-extinguishing cavity, arc interference is eliminated, and the arc energy is evenly distributed to the two arc-extinguishing cavities for parallel processing, avoiding single-cavity overload, significantly shortening the arc-extinguishing time and reducing the ablation of each pair of arc-initiating contacts. This layout realizes dual-path current diversion of arc energy, significantly improves the ultimate short-circuit breaking capacity and operational reliability of the circuit breaker, and extends the service life of the entire unit.

[0022] 4. In the high breaking capacity frame circuit breaker provided by this utility model, the magnetic blow-out component is composed of multiple permanent magnets stacked in the same direction and fixed at the bottom of the arc-initiating stationary contact. When the arc-initiating moving contact and the arc-initiating stationary contact break and generate an arc, the directional strong magnetic field generated by the multiple permanent magnets applies a Lorentz force to the charged arc, forcibly blowing the arc quickly into the gap of the arc-extinguishing grid in the corresponding arc-extinguishing cavity. This significantly shortens the residence time of the arc in the contact area, reduces the erosion and loss of the contact, and works with the arc-initiating plate to accelerate the arc into the arc-extinguishing cavity along a preset path, avoiding arc retention or deflection. This design achieves the function of magnetic blow-out arc initiation, enhances the arc initiation and arc extinguishing efficiency under short-circuit high current, reduces arc voltage and suppresses arc reignition, and significantly improves the breaking capacity and contact life of the circuit breaker. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 A schematic diagram of the high breaking capacity frame circuit breaker provided by this utility model;

[0025] Figure 2 This is a schematic diagram of the connection structure between the contact system and the arc-extinguishing structure of this utility model;

[0026] Figure 3 This is a cross-sectional schematic diagram of the contact system and arc-extinguishing structure of this utility model;

[0027] Figure 4 for Figure 2 The top view of the contact system and arc-extinguishing structure is shown, with a particular cross-section of the arc-extinguishing structure shown.

[0028] Figure 5 This is a schematic diagram of the arc-extinguishing chamber body and the arc-extinguishing chamber body of this utility model.

[0029] Explanation of reference numerals in the attached drawings: 1. Shell; 2. Arc-extinguishing chamber body; 21. Arc-extinguishing cavity; 22. Arc-extinguishing plate assembly; 31. First arc-inducing plate; 32. Second arc-inducing plate; 33. Bending arc-inducing angle; 4. Arc-extinguishing chamber body; 41. Arc-extinguishing cover; 42. Arc-extinguishing plate; 43. Arc-extinguishing cavity; 5. Moving contact assembly; 51. Active contact; 52. Arc-inducing moving contact; 53. Contact frame; 6. Stationary contact assembly; 61. Main stationary contact; 62. Arc-inducing stationary contact; 63. Outgoing busbar; 64. Connecting busbar; 7. Insulating partition; 8. Magnetic blower; 9. Insulating gas-generating cushion. Detailed Implementation

[0030] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0031] In the description of this utility model, it should be noted that the terms "first", "second" and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0032] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0033] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0034] Example

[0035] The following is a detailed description of this embodiment with reference to the accompanying drawings:

[0036] This embodiment provides, as follows: Figures 1-5 A high breaking capacity frame circuit breaker is shown, including a housing 1 and a contact system, an arc extinguishing structure and an operating mechanism disposed within the housing 1. The arc extinguishing structure includes an arc extinguishing chamber 2 and two arc extinguishing cavities 21 spaced apart within the arc extinguishing chamber 2, and an arc extinguishing chamber 4 connected to the rear ends of the two arc extinguishing cavities 21. Arc extinguishing plate assemblies 22 are respectively disposed in the two arc extinguishing cavities 21.

[0037] The contact system includes a moving contact assembly 5 and a stationary contact assembly 6. The operating mechanism drives the moving contact assembly 5 and the stationary contact assembly 6 to engage or disengage, thereby realizing the closing or opening operation of the circuit breaker. The stationary contact assembly 6 includes a main stationary contact 61 and two sets of arc-inducing stationary contacts 62 electrically connected to the main stationary contact 61. The main stationary contact 61 is located outside the openings of the two arc-extinguishing chambers 21, and the two sets of arc-inducing stationary contacts 62 are respectively arranged at the bottom of the openings at the front ends of the two arc-extinguishing chambers 21. The moving contact assembly 5 includes a moving contact assembly 5 and a stationary contact assembly 6. The contact 61 has multiple active contacts 51 and two sets of arc-inducing active contacts 52 spaced apart between the multiple active contacts 51. The length of the two sets of arc-inducing active contacts 52 is greater than the length of the active contacts 51, and they extend into the openings of the two arc-extinguishing chambers 21 to make contact with the corresponding two sets of arc-inducing stationary contacts 62. During the circuit breaker tripping process, the multiple active contacts 51 separate from the corresponding main stationary contacts 61 before the two sets of arc-inducing active contacts 52, and then the two sets of arc-inducing active contacts 52 separate from the corresponding two sets of arc-inducing stationary contacts 62.

[0038] In the above embodiments, by setting up a double arc-extinguishing chamber and matching it with two sets of arc-extinguishing plate assemblies in the arc-extinguishing chamber body 2, the arc-extinguishing arrangement space is greatly expanded and the number of arc-extinguishing plates is increased. This can fully cut the segmented arc and enhance the near-cathode arc-extinguishing effect. After the arc is extinguished and cooled by the double arc-extinguishing chamber, it still needs to pass through the arc-extinguishing chamber body 4 for secondary arc-extinguishing purification to remove residual arc and high-temperature plasma, prevent the re-ignition caused by weak residual arc, and efficiently conduct and dissipate arc heat. This design significantly increases the overall capacity of the arc-extinguishing chamber and can reliably interrupt higher-level large currents. At the same time, relying on the double arc-extinguishing chamber and the two sets of arc-igniting moving contacts 52 to form independent arc-ignition paths, the arc energy is evenly distributed to the two arc-extinguishing chambers and By performing arc extinguishing treatment, overload or pressure imbalance of a single arc extinguishing chamber can be avoided, and short-circuit arc shunting and diversion can be achieved, dispersing arc thermal shock and electrical stress, significantly shortening arc extinguishing time and reducing the degree of ablation on the arc-initiating moving contact 52. This ensures that the arc is stably and quickly introduced into the arc extinguishing chamber 21 to complete arc extinguishing. This effectively solves the defect of insufficient breaking capacity of traditional arc extinguishing chambers. This technical solution, combined with the breaking sequence of the active contact 51 separating first and the arc-initiating moving contact 52 opening later, can completely transfer the arc to the arc-initiating moving contact area, protecting the active contact from arc ablation, effectively extending the service life of the circuit breaker as a whole and the core contacts and arc extinguishing structure, and improving the overall arc extinguishing efficiency and ultimate short-circuit breaking capacity of the circuit breaker.

[0039] The following is combined with 2- Figure 5 The specific structures of arc-extinguishing chamber 2 and arc-extinguishing chamber 4 are described in detail below:

[0040] The two arc-extinguishing chambers 21 are respectively the first arc-extinguishing chamber 21 and the second arc-extinguishing chamber 21, which are arranged side by side and separated, and together form an integrated double arc-extinguishing chamber structure. The arc-extinguishing plate assembly 22 includes multiple arc-extinguishing grid plates arranged in parallel and spaced apart in each set of arc-extinguishing chambers 21. Further preferably, a first arc-inducing plate 31 is correspondingly arranged in both the first and second arc-extinguishing chambers. The first arc-inducing plate 31 is arranged on the top of the arc-extinguishing plate assembly 22. The first arc-inducing plate 31 has a bent arc-inducing end that extends out of the arc-extinguishing chamber 21 and is arranged close to the opening and closing trajectory of the active contact 51. This design integrates the first and second arc-extinguishing chambers into a single, parallel, dual-chamber configuration. The two chambers are mutually isolated, preventing arc interference. Multiple parallel arc-extinguishing grids within the chambers evenly divide the arc and enhance heat dissipation and arc extinguishing effects. The arc-initiating moving contact 52 and the arc-initiating stationary contact 62 engage or disengage within the opening range of their respective arc-extinguishing chambers, and are very close to the arc-extinguishing grids. This facilitates the rapid introduction of the arc concentrated in the area of ​​the arc-initiating moving contact 52 into the arc-extinguishing grids. Furthermore, each arc-extinguishing chamber 21 is independently designed... A first arc-initiating plate 31 is configured on the top of the arc-extinguishing grid. The arc-initiating end of the first arc-initiating plate 31 extends outward and is close to the opening and closing trajectory of the active contact 51. This allows the weak initial arc generated when the active contact breaks to be quickly diverted and drawn into the arc-extinguishing grid to extinguish the arc, completely preventing the arc from remaining on the surface of the active contact and avoiding the active contact from being burned by the arc. By using two arc-initiating structures to independently guide and divert the arc, the arc direction is made stable and controllable, further optimizing the arc-initiating efficiency, ensuring smooth dual-cavity arc extinguishing, and steadily improving the overall breaking protection performance.

[0041] like Figure 3As shown, the arc-extinguishing chamber 4 includes an arc-extinguishing cover 41, multiple arc-extinguishing plates 42, and an arc-extinguishing cavity 43. The arc-extinguishing cover 41 is fixedly connected to the rear end of the arc-extinguishing chamber 2 and encloses the arc-extinguishing cavity 43 to form a closed cavity. The arc-extinguishing cavity 43 is connected to the first arc-extinguishing cavity and the second arc-extinguishing cavity. The multiple arc-extinguishing plates 42 are arranged parallel to each other in the arc-extinguishing cavity 43 along the arrangement direction perpendicular to the arc-extinguishing grid plates. Each arc-extinguishing plate 42 is provided with several arc-extinguishing holes. The rear side plate of the arc-extinguishing cover 41, which is opposite to the arc-extinguishing plates 42, is provided with several exhaust holes. In this structural configuration, the arc-extinguishing chamber 4 and the arc-extinguishing chamber 2 are directly connected, allowing the residual electric arc, high-temperature plasma, and incandescent arc gas remaining after the previous arc extinguishing to be collected in the arc-extinguishing chamber 43. Multiple arc-extinguishing plates in the arc-extinguishing chamber 43 are arranged perpendicularly to the arc-extinguishing grid plates in the arc-extinguishing chamber 21. These multiple arc-extinguishing plates 42 extinguish the residual electric arc and block some large metal particles, while also providing multiple deionization treatments for charged free gases, thus achieving the effect of absorbing and neutralizing charged free gases. Finally, the cooled hot gas is smoothly discharged through the exhaust vents on the arc-extinguishing cover, releasing internal pressure and preventing hot gas backflow that could reignite the arc. The entire process achieves step-by-step arc extinguishing and purification, digesting all arc energy within the arc-extinguishing and arc-extinguishing structure, better achieving the requirement of zero arc flashover, preventing external arc ejection, external flashover, and ablation of surrounding components, and significantly improving the circuit breaker's breaking safety and operational reliability.

[0042] The following is combined Figures 1-4 The specific configuration methods for the moving contact assembly and the stationary contact assembly are explained in detail:

[0043] The main stationary contact 61 is fixedly mounted on the outgoing busbar 63, and two sets of arc-inducing stationary contacts 62 are respectively mounted on the connecting busbar 64. The arc-inducing stationary contacts 62 are fixedly connected to the outgoing busbar 63 or integrally formed through the connecting busbar 64 to achieve low-resistance conduction with the main stationary contact 61. The connecting busbar 64 is fixedly connected to the outgoing busbar 63 or integrally formed to achieve electrical connection between the arc-inducing stationary contact 62 and the main stationary contact 61. The two sets of arc-inducing stationary contacts 62 and the main stationary contact 61 are arranged parallel to each other along the arrangement direction of multiple active contacts, so that they can be precisely aligned with the active contact 51 and the arc-inducing moving contact 52.

[0044] In a further preferred configuration, each set of arc-extinguishing cavities 21 is also provided with a second arc-inducing plate 32, which is located at the bottom of the arc-extinguishing plate assembly 22 of the corresponding arc-extinguishing cavity 21; one end of the second arc-inducing plate extends and is fixedly connected to the connecting bar 64 or the arc-inducing stationary contact 62, and the other end extends along the arc-entry direction of the arc-extinguishing cavity 21 into the corresponding arc-extinguishing cavity 21, specifically, the second arc-inducing plate is fixedly connected to the connecting bar by screws; wherein, the second arc-inducing plate 32 is bent into a bent arc-inducing angle 33 near the arc-inducing stationary contact 62; the bent arc-inducing angle 33 has two arc-inducing inclined surfaces set at a preset included angle. In this structural configuration, the second arc-inducing plate 32 is bent to form a bent arc-inducing angle 33 with double arc-inducing slopes. One of the arc-inducing slopes contacts the end slope of the connecting busbar 64, directly receiving the arc generated by the broken arc of the arc-inducing stationary contact 62. This prevents the arc from spreading to the main stationary contact 61, the outgoing busbar 63, and other main circuit components, protecting the main circuit from ablation. The other arc-inducing slope extends towards the arc-extinguishing plate assembly 22 in the corresponding arc-extinguishing cavity 21, guiding the arc into the gap of the arc-extinguishing grid at a suitable angle. This angled arc is more easily blown away. The arc extinguishing grid is inserted deeper to achieve arc extinguishing. The second arc-initiating plate 32 of this structural design uses the guiding effect of the double arc-initiating inclined surface to change the initial movement direction of the arc. Combined with the electric field concentration effect at the bend, the arc generated by the arc-initiating stationary contact 62 is quickly and smoothly guided into the arc-extinguishing grid area inside the arc-extinguishing cavity along the inclined surface. This greatly shortens the movement path of the arc from the contact to the arc-extinguishing grid, reduces the residence time of the arc in the arc-initiating stationary contact area, and reduces the erosion loss of the arc-initiating stationary contact. This enhances the stability and reliability of arc extinguishing on the stationary contact side and greatly improves the overall breaking performance and service life of the circuit breaker.

[0045] In summary, by arranging the first arc-initiating piece 31 and the second arc-initiating piece 32 on the top and bottom of each arc-extinguishing cavity respectively, an enclosed arc-initiating structure is formed, which prevents the arc from deflecting and escaping, and ensures that the arc enters the arc-extinguishing cavity 21 for extinguishing. Combined with the independent arc-initiating design between the two sets of arc-initiating moving contacts and the double arc-extinguishing cavities, arc interference is eliminated, and the arc energy is evenly distributed to the two arc-extinguishing cavities 21 for parallel processing, avoiding single-cavity overload, significantly shortening the arc-extinguishing time and reducing the erosion of each pair of arc-initiating contacts. This layout achieves dual-path current distribution of arc energy, significantly improves the ultimate short-circuit breaking capacity and operational reliability of the circuit breaker, and extends the overall service life.

[0046] like Figure 3As shown, an insulating gas-generating pad 9 is provided on the connecting busbar 64. The insulating gas-generating pad 9 surrounds the outside of the arc-initiating stationary contact 62 and covers the exposed conductive surfaces of the connecting busbar 64 and the outgoing busbar 63. This design improves the creepage distance and electrical clearance tolerance between the main stationary contact 61 and the arc-initiating stationary contact 62, and achieves insulation isolation between the arc-initiating area and the main circuit and surrounding components. At the same time, the insulating gas-generating pad 9 will rapidly decompose and generate a large amount of gas under the high temperature of the arc. These gases expand to form a high-pressure airflow, which propels the arc to move rapidly along the preset arc-initiating path, preventing the arc from stagnating near the stationary contact and burning the contact. This achieves the functions of insulation isolation, high-temperature gas generation to blow away the arc, cooling the arc, and protecting the busbar.

[0047] In order to quickly guide the electric arc into the gap between the arc-extinguishing grid plates to achieve arc extinguishing, combined with Figures 2-3 As shown, each set of arc-inducing stationary contacts 62 is provided with a magnetic blower 8 at its bottom. The magnetic blower 8 is used to generate a strong magnetic blowing force when the contacts break to quickly blow the arc into the gap of the arc-extinguishing grid plate in the corresponding arc-extinguishing cavity 21. The magnetic blower 8 is composed of multiple permanent magnets stacked in the same direction and is fixed between the bottom of the arc-inducing stationary contact 62 and the second arc-inducing plate 32. The magnetic field directions of the multiple permanent magnets are arranged in the same direction. This structural design, when the arc-initiating moving contact 52 and the arc-initiating stationary contact 62 break and generate an arc, utilizes multiple parallel-mounted permanent magnets to generate a strong magnetic field, applying a magnetic blowing force perpendicular to both the current direction and the magnetic field direction to the broken arc. This forces the arc to be quickly blown into the gap between the arc-extinguishing grid plates in the corresponding arc-extinguishing cavity 21. This significantly shortens the arc's dwell time in the contact area, reducing contact erosion and wear. In conjunction with the arc-initiating plates, it accelerates the arc into the arc-extinguishing cavity along a preset path, preventing arc retention or deflection. This design achieves the function of magnetic arc initiation, enhancing the arc initiation and extinguishing efficiency under short-circuit high current, reducing arc voltage and suppressing arc reignition, and significantly improving the circuit breaker's breaking capacity and contact life.

[0048] Combination Figures 1-3As shown, the moving contact assembly 5 includes a contact frame 53 rotatably mounted on the housing. The active contact 51 and the arc-inducing moving contact 52 are both mounted on the contact frame 53. The active contact 51 and the arc-inducing moving contact 52 are respectively connected to the incoming busbar via flexible connections. An insulating partition 7 is provided on the side of the contact frame 53 facing the outgoing busbar 63. The insulating partition 7 extends and is arranged opposite to the sidewalls of the main stationary contact 61 and the outgoing busbar 63. The advantage of this design is that during the circuit breaker tripping process, the insulating partition 7 rotates with the contact frame 53 and approaches the outgoing busbar 63, making contact with or against the side wall of the outgoing busbar 63. This forms an isolation barrier between the contact frame 53 and the outgoing busbar 63, which can prevent the arc and high-temperature plasma generated during the contact tripping process from moving into the circuit breaker body and prevent the arc light and high temperature from corroding the internal components. This ensures that the arc high temperature can only move towards the arc extinguishing chamber, strictly enclosing the arc in the arc extinguishing chamber and the arc ignition area. Combined with the arc ignition plate, magnetic blower and double arc extinguishing chamber structure, this design prevents the arc from moving randomly inside the circuit breaker and further ensures the rapid and complete extinguishing of the arc.

[0049] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A high breaking capacity frame circuit breaker, comprising a housing (1) and a contact system, an arc extinguishing structure, and an operating mechanism disposed within the housing, characterized in that: The arc extinguishing structure includes an arc extinguishing chamber (2) and two arc extinguishing cavities (21) formed at intervals within the arc extinguishing chamber (2), as well as an arc extinguishing chamber (4) connected to the rear ends of the two arc extinguishing cavities (21). Arc extinguishing plate assemblies (22) are respectively provided in the two arc extinguishing cavities (21). The contact system includes a moving contact assembly (5) and a stationary contact assembly (6); the stationary contact assembly (6) includes a main stationary contact (61) and two sets of arc-inducing stationary contacts (62) electrically connected to the main stationary contact (61). The main stationary contact (61) is located outside the openings of the two arc-extinguishing cavities (21), and the two sets of arc-inducing stationary contacts (62) are respectively arranged at the bottom of the openings at the front end of the two arc-extinguishing cavities (21); the moving contact assembly (5) includes multiple active contacts (51) corresponding to the main stationary contact (61), and two sets of arc-inducing moving contacts (52) spaced apart between the multiple active contacts (51). The two sets of arc-inducing moving contacts (52) extend into the openings of the two arc-extinguishing cavities (21) and make contact with the corresponding two sets of arc-inducing stationary contacts (62); During the circuit breaker tripping process, multiple active contacts (51) separate from the corresponding main stationary contacts (61) before the two sets of arc-inducing moving contacts (52), and then the two sets of arc-inducing moving contacts (52) separate from the corresponding two sets of arc-inducing stationary contacts (62).

2. The high breaking capacity frame circuit breaker according to claim 1, characterized in that: The two arc-extinguishing chambers (21) are the first arc-extinguishing chamber and the second arc-extinguishing chamber, which are arranged side by side and separated, and together form an integrated double arc-extinguishing chamber structure. The arc-extinguishing plate assembly (22) includes multiple arc-extinguishing grid plates arranged in parallel and spaced apart in each group of arc-extinguishing chambers (21).

3. The high breaking capacity frame circuit breaker according to claim 2, characterized in that: The first arc-extinguishing cavity and the second arc-extinguishing cavity are each provided with a first arc-inducing plate (31); the first arc-inducing plate is arranged on the top of the arc-extinguishing plate assembly (22), and the first arc-inducing plate (31) has a bent arc-inducing end that extends out of the arc-extinguishing cavity (21), and the bent arc-inducing end is arranged close to the opening and closing trajectory of the active contact (51).

4. The high breaking capacity frame circuit breaker according to claim 1, characterized in that: The main stationary contact (61) is fixedly mounted on the outgoing busbar (63), and two sets of arc-inducing stationary contacts (62) are respectively mounted on the connecting busbar (64). The two sets of arc-inducing stationary contacts (62) and the main stationary contact (61) are arranged parallel to each other along the direction of multiple active contacts. The connecting busbar (64) is fixedly connected to the outgoing busbar (63) or integrally formed to realize the electrical connection between the arc-inducing stationary contact (62) and the main stationary contact (61).

5. The high breaking capacity frame circuit breaker according to claim 4, characterized in that: Each of the arc-extinguishing cavities (21) is also provided with a second arc-inducing plate (32), which is located at the bottom of the arc-extinguishing plate assembly (22) of the corresponding arc-extinguishing cavity (21). One end of the second arc-inducing plate (32) extends and is fixedly connected to the connecting bar (64) or the arc-inducing stationary contact (62), and the other end extends into the corresponding arc-extinguishing cavity (21) along the arc-entry direction.

6. The high breaking capacity frame circuit breaker according to claim 5, characterized in that: The second arc-inducing plate (32) is bent into an arc-inducing angle (33) near the arc-inducing stationary contact (62); the arc-inducing angle (33) has two arc-inducing inclined surfaces set at a preset angle, one of which contacts the end fitting inclined surface of the connecting row (64); the other arc-inducing inclined surface extends toward the side of the arc-extinguishing plate assembly (22) in the corresponding arc-extinguishing cavity (21).

7. The high breaking capacity frame circuit breaker according to claim 4, characterized in that: An insulating gas-generating pad (9) is provided on the connecting bus (64). The insulating gas-generating pad (9) surrounds the outside of the arc-initiating stationary contact (62) and covers the exposed conductive surfaces of the connecting bus (64) and the outgoing busbar (63).

8. The high breaking capacity frame circuit breaker according to any one of claims 1-7, characterized in that: Each set of arc-initiating stationary contacts (62) is provided with a magnetic blower (8) at the bottom. The magnetic blower (8) is used to generate a strong magnetic blowing force when the contacts break to quickly blow the arc into the gap of the arc-extinguishing grid plate in the corresponding arc-extinguishing cavity (21). The magnetic blower (8) is composed of multiple permanent magnets stacked in the same direction and is fixed between the bottom of the arc-initiating stationary contact (62) and the second arc-initiating plate (32). The magnetic field directions of the multiple permanent magnets are arranged in the same direction.

9. The high breaking capacity frame circuit breaker according to claim 1, characterized in that: The moving contact assembly (5) includes a contact frame (53) rotatably mounted on the housing (1), and the active contact (51) and the arc-inducing moving contact (52) are both mounted on the contact frame (53); an insulating partition (7) is provided on the side of the contact frame (53) facing the outgoing busbar (63), and the insulating partition (7) extends and is arranged opposite to the side wall of the main stationary contact (61) and the outgoing busbar (63).

10. The high breaking capacity frame circuit breaker according to claim 1, characterized in that: The arc-extinguishing chamber (4) includes an arc-extinguishing cover (41), multiple arc-extinguishing plates (42), and an arc-extinguishing cavity (43). The arc-extinguishing cover (41) is fixedly connected to the rear end of the arc-extinguishing chamber (2) and encloses the arc-extinguishing cavity (43) to form a closed cavity. The arc-extinguishing cavity (43) is connected to both arc-extinguishing cavities (21). The multiple arc-extinguishing plates (42) are arranged parallel to each other in the arc-extinguishing cavity (43) along the arrangement direction perpendicular to the arc-extinguishing grid. Each arc-extinguishing plate (42) has several arc-extinguishing holes. The rear side plate of the arc-extinguishing cover (41) and the arc-extinguishing plates (42) are provided with several exhaust holes.

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