An arc extinguishing system

Abstract

The invention discloses an arc extinguishing system, which relates to the field of circuit breakers. The system includes a bracket, a narrow slot structure and an arc extinguishing chamber; the arc extinguishing chamber includes a first arc extinguishing chamber and a second arc extinguishing chamber, and the first arc extinguishing chamber and the second arc extinguishing chamber are electrically isolated from each other; a first arc extinguishing grid group is arranged inside the first arc extinguishing chamber, and a second arc extinguishing grid group is arranged inside the second arc extinguishing chamber; the narrow slot structure separates the first narrow slot structure and the second narrow slot structure from one end to the other end, and the first narrow slot structure and the second narrow slot structure are arranged at an angle, and are respectively oriented toward the first arc extinguishing grid group and the second arc extinguishing grid group, forming two arc extinguishing channels. The invention can effectively reduce the volume of the circuit breaker, greatly reduce the arcing distance, constrain the arc diameter, length and path, and improve the arc extinguishing effect.

Description

Technical Field

[0001] The invention relates to the technical field of circuit breakers, and in particular to an arc extinguishing system. Background Art

[0002] A circuit breaker is a mechanical switch that can connect, carry and disconnect current under normal circuit conditions, and can also connect, carry for a certain time and disconnect current under specified abnormal circuits. At present, low-voltage circuit breakers generally use the near-pole voltage drop and deionization effect of arc-extinguishing grids to increase the arc voltage and dielectric recovery strength, extinguish the arc and prevent the arc from reigniting. The more grids there are, the greater the arc voltage formed by the sum of the near-pole voltage drops, and the better the deionization effect. When the arc voltage exceeds the power supply voltage, the arc is extinguished. Therefore, the ability to disconnect arcs at higher voltages depends on the number of available grids, but arranging more grids requires more space. The greater space requirement will increase the product size, increase the cost, and make it inconvenient for users. On the basis of limited space and a limited number of grids, continuing to increase the arc voltage often requires measures such as increasing the arc length and reducing the arc cross-section through a narrow slit structure. At the same time, because the arc length required at higher voltages such as AC and DC 1500V is longer, and the ability of a single narrow slot structure to lengthen the arc is limited, it is not conducive to the use of arc extinguishing systems with multi-grid group structures. Based on this, how to improve the arc extinguishing effect of the arc extinguishing system, shorten the arcing distance, and not increase the volume through the reliable cooperation of the narrow slot structure and the multi-grid group, so as to make it suitable for higher working voltages, is a difficult problem that needs to be solved urgently in the current field. Summary of the invention

[0003] The purpose of the present invention is to provide an arc extinguishing system that can be applicable to higher rated working voltages, can effectively reduce the size of the circuit breaker, significantly reduce the arcing distance, constrain the arc diameter, length and path, and improve the arc extinguishing effect.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] The present invention provides an arc extinguishing system, which constitutes a circuit breaker with a contact system. The contact system includes a moving contact system and a stationary contact system. The moving contact system includes an arc contact. The arc extinguishing system includes a bracket, a narrow slot structure arranged in front of the bracket and accommodating the arc contact, and an arc extinguishing chamber arranged behind the bracket.

[0006] The arc extinguishing chamber comprises a first arc extinguishing chamber and a second arc extinguishing chamber, the first arc extinguishing chamber and the second arc extinguishing chamber are electrically isolated from each other; a first arc extinguishing grid group is arranged inside the first arc extinguishing chamber, and a second arc extinguishing grid group is arranged inside the second arc extinguishing chamber.

[0007] The narrow slot structure is a narrow slot-shaped hollow structure, and a first narrow slot structure and a second narrow slot structure are separated from one end to the other end of the narrow slot structure. The first narrow slot structure and the second narrow slot structure are arranged at an angle, and the first narrow slot structure and the second narrow slot structure are respectively oriented toward the first arc-extinguishing grid group and the second arc-extinguishing grid group to form two arc-extinguishing channels; the narrow slot structure is used for causing the arc generated at the arc contact to reach the first arc-extinguishing grid group and the second arc-extinguishing grid group along the two arc-extinguishing channels to achieve arc extinguishing after the circuit is disconnected.

[0008] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0009] The present invention proposes an arc extinguishing system, which can be applied to circuit breakers with higher rated working voltages. It adopts a series connection method in which multiple arc extinguishing chambers are arranged in parallel. By dividing the arc extinguishing system into two arc extinguishing chambers arranged in parallel, namely, a first arc extinguishing chamber and a second arc extinguishing chamber, the two arc extinguishing chambers are electrically isolated, thereby effectively reducing the volume of the circuit breaker, so that the arc extinguishing system has the ability to single-pole interrupt the full voltage short-circuit current, and greatly reduces the arcing distance. At the same time, a special structure in which a single narrow slit structure is dispersed into two narrow slit structures is adopted to maximize the length of the arc within a limited volume. The double narrow slit structure can compress the diameter of the arc and constrain the movement path of the arc, thereby improving the utilization rate of the grid and enhancing the ion elimination effect. In addition, the arc extinguishing system of the present invention can cooperate with the contact system to isolate the contact system from the arc extinguishing system. The arc diameter is constrained by the narrow slit structure, so that the arc electric field is more concentrated, which is conducive to constraining the arc path and easily forming a more concentrated induced magnetic field, thereby improving the performance and arc extinguishing effect of the arc extinguishing system. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0011] Figure 1 A schematic diagram of the relative positions of an arc extinguishing system provided in Embodiment 1 of the present invention;

[0012] Figure 2 A schematic diagram of the relative positions of the arc extinguishing system after removing a cover plate on one side and part of the bracket provided in Example 1 of the present invention;

[0013] Figure 3 A schematic diagram of the relative positions of only the moving arc-striking plate and the static arc-striking plate of the arc-extinguishing system provided in Embodiment 1 of the present invention;

[0014] Figure 4 This is a schematic isometric diagram of the arc-entry side of the arc extinguishing system provided in Example 1 of the present invention;

[0015] Figure 5 This is a schematic isometric diagram of the arc-exiting side of the arc extinguishing system provided in Example 1 of the present invention;

[0016] Figure 6 This is a schematic isometric diagram of the arc-entry side of the arc extinguishing system provided in Example 1 of the present invention;

[0017] Figure 7 This is an axonometric diagram of the arc extinguishing system provided in Example 1 of the present invention without the right cover plate;

[0018] Figure 8 An axonometric schematic diagram of the arc extinguishing system provided in Example 1 of the present invention without the left cover plate;

[0019] Fig. 9 A plan view of the arc extinguishing system provided in Example 1 of the present invention after removing the left cover plate and baffle;

[0020] Fig.10 A plan view of the arc extinguishing system provided in Example 1 of the present invention after removing the right cover plate and baffle;

[0021] Fig.11 A schematic diagram of the structure of the arc extinguishing system provided in Example 1 of the present invention after removing the bracket and the cover plate;

[0022] Fig.12 An axonometric diagram of the arc extinguishing system provided in Example 1 of the present invention without the support cover plate and the U-shaped magnetizing sheet group;

[0023] Fig.13 A schematic diagram of the arrangement of the arc extinguishing grid group and the dynamic and static arc striking plates of the arc extinguishing system provided in Example 1 of the present invention;

[0024] Fig.14 A schematic diagram of arc movement direction of an arc extinguishing system without a bracket and a cover plate provided in Example 1 of the present invention;

[0025] Fig.15 A schematic isometric diagram of the arc movement direction of the arc extinguishing system without the bracket and the cover plate provided in Example 1 of the present invention;

[0026] Fig.16 A bottom plan view of the bracket provided in Example 1 of the present invention;

[0027] Fig.17 A schematic diagram of the arc movement direction of the first arc extinguishing chamber of the bracket provided in Example 1 of the present invention;

[0028] Fig.18 A front view of the bracket and a schematic diagram of the arc movement direction provided in Example 1 of the present invention;

[0029] Fig.19 A top plan view of a bracket provided in Example 1 of the present invention;

[0030] Fig. 20 A schematic diagram of the arc movement direction of the second arc extinguishing chamber of the bracket provided in Example 1 of the present invention;

[0031] Fig.21 A schematic diagram of the arc at the arc entrance and the airflow movement direction of the arc extinguishing system provided in Example 1 of the present invention;

[0032] Fig. 22 A plan view of the arc extinguishing system provided in Example 2 of the present invention after removing the left cover plate and baffle;

[0033] Fig.23 A plan view of the arc extinguishing system provided in Example 1 of the present invention after removing the right cover plate and baffle;

[0034] Fig.24 A schematic diagram of the relative relationship between the first arc-starting plate and the second arc-starting plate provided in Example 1 of the present invention;

[0035] Fig.25 A schematic diagram of an arc striking cut provided in Example 1 of the present invention;

[0036] Fig.26 A schematic diagram of arc motion trend provided in Example 1 of the present invention;

[0037] Fig. 27 A schematic diagram of the current at the initial stage of disconnection provided by Embodiment 1 of the present invention;

[0038] Fig.28 A schematic diagram of current and arc movement at the initial stage of contact opening provided by Embodiment 1 of the present invention;

[0039] Fig.29 A schematic diagram of current and arc movement during the middle of disconnection provided by Embodiment 1 of the present invention;

[0040] Fig.30 A schematic diagram of the current and arc movement in the first arc extinguishing chamber at the end of the breaking period provided by Embodiment 1 of the present invention;

[0041] Fig.31 This is a schematic diagram of the current and arc movement in the second arc extinguishing chamber at the end of the disconnection period provided in Example 1 of the present invention.

[0042] Explanation of reference numerals: 1. Static contact system; 2. Moving contact system; 3. Arc extinguishing system; 9. Arc contact; 10. Arc-striking silver point; 19. Cover plate; 20. Bracket; 21. Guide plate; 22. Gas-generating plate; 23. U-shaped magnetizing plate group; 24. Moving arc-striking plate; 25. Arc-striking grid group; 26. First arc-striking chamber; 27. Second arc-striking chamber; 28. Static arc-striking plate; 29. ​​Platform structure; 30. Baffle; 31. First arc-striking grid; 32. Second arc-striking grid; 33. Guide slope; 34. First arc-entry port; 35. Second arc-entry port; 36. Soft connection; 39. Groove structure; 40. Slit structure; 41. First narrow slit structure; 42. Second narrow slit structure; 45. Insulating sleeve; 47. Cylindrical structure; 48. Arc-striking cut. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] At present, the existing arc extinguishing system has poor arc extinguishing performance, high requirements for installation space, which is not conducive to reducing costs, and has low reliability and a large arcing distance. In addition, when breaking the critical load current under a higher DC voltage, due to the low current, the effects of magnetic blowing and air blowing are reduced. At present, the method of adding permanent magnets is often used to enhance the magnetic blowing effect, so that the arc enters the arc extinguishing chamber and completes the breaking. However, the DC circuit breaker with permanent magnets has polarity requirements. Current breaking under the condition of incorrect wiring polarity will cause more serious consequences. With the increase of the service life of the permanent magnet, the high temperature effect of the arc on it during breaking, and the high temperature of the circuit breaker itself when operating at a high ambient temperature, the magnetism of the permanent magnet will gradually decrease under the influence of the inherent temperature rise of the circuit breaker, resulting in a reduction in the magnetic blowing effect, which has a great impact on the breaking performance, reliability and service life of the circuit breaker.

[0045] The purpose of the present invention is to provide an arc extinguishing system that can be applicable to higher rated working voltages, can effectively reduce the size of the circuit breaker, significantly reduce the arcing distance, constrain the arc diameter, length and path, and improve the arc extinguishing effect.

[0046] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. Example

[0047] like Figure 1As shown, this embodiment proposes an arc extinguishing system, which arc extinguishing system 3 can form a circuit breaker with a contact system, wherein the contact system includes a moving contact system 2 and a stationary contact system 1, wherein the moving contact system 2 includes an arc contact 9, and the arc extinguishing system 3 includes a bracket 20, a narrow slot structure 40 arranged in front of the bracket 20 and accommodating the arc contact 9, and an arc extinguishing chamber arranged behind the bracket 20.

[0048] In this embodiment, the arc extinguishing chamber includes a first arc extinguishing chamber 26 and a second arc extinguishing chamber 27 , and the first arc extinguishing chamber 26 and the second arc extinguishing chamber 27 are electrically isolated from each other.

[0049] In this embodiment, a first arc-extinguishing grid group is disposed inside the first arc-extinguishing chamber 26, and a second arc-extinguishing grid group is disposed inside the second arc-extinguishing chamber 27. The first arc-extinguishing grid group and the second arc-extinguishing grid group both include a plurality of arc-extinguishing grids, and the first arc-extinguishing grid group and the second arc-extinguishing grid group are arranged at an angle.

[0050] In this embodiment, the narrow slot structure 40 is a narrow slot-shaped hollow structure, and the narrow slot structure 40 is separated into a first narrow slot structure 41 and a second narrow slot structure 42 from one end to the other end. The first narrow slot structure 41 and the second narrow slot structure 42 are arranged at an angle, and the first narrow slot structure 41 and the second narrow slot structure 42 are respectively oriented toward the first arc-extinguishing grid group and the second arc-extinguishing grid group to form two arc-extinguishing channels; the narrow slot structure 40 is used to make the arc generated at the arc contact 9 reach the first arc-extinguishing grid group and the second arc-extinguishing grid group along the two arc-extinguishing channels to achieve arc extinguishing after the circuit is disconnected.

[0051] In this embodiment, a first arc-striking grid 31 and a second arc-striking grid 32 are further included. The end of the first arc-striking grid 31 is arranged at the top of the first arc-extinguishing grid group, and the end of the second arc-striking grid 32 is arranged at the bottom of the second arc-extinguishing grid group, and the starting end of the first arc-striking grid 31 is overlapped with the starting end of the second arc-striking grid 32 and is electrically connected.

[0052] The first arc-striking grid 31 and the second arc-striking grid 32 are used to direct the arc to the first arc-extinguishing grid group and the second arc-extinguishing grid group, respectively.

[0053] In this embodiment, a movable arc-striking plate 24 is further included. The movable arc-striking plate 24 is arranged on the top of the second arc-extinguishing grid group. The movable arc-striking plate 24 is used to guide the arc to the second arc-extinguishing grid group.

[0054] In this embodiment, a static arc-striking plate 28 is further included. The static arc-striking plate 28 is arranged at the bottom of the first arc-extinguishing grid group. The static arc-striking plate 28 is used to connect the static contact system 1.

[0055] In this embodiment, a platform structure 29 is provided on the static arc-striking plate 28. The platform structure 29 is used to form an arc-striking zone between the arc contact 9 and the platform structure 29 after contacting the arc-striking silver point 10 of the arc contact 9. The arc-striking zone is the area where an arc is generated.

[0056] In this embodiment, a U-shaped magnetizing plate group 23 is arranged below the platform structure 29, and the U-shaped magnetizing plate group 23 includes a U-shaped arm, and the U-shaped arm is arranged on the bracket 20 and the opening of the U-shaped arm faces the narrow gap structure 40. The arc generating zone is located within the range of the U-shaped arm, and the U-shaped magnetizing plate group is used to form an induced magnetic field around the arc generating zone, so that the arc generated in the arc generating zone moves toward the direction of the narrow gap structure 40 under the action of the magnetic force of the induced magnetic field.

[0057] In this embodiment, guide plates 21 are provided at the ends of the first arc-extinguishing grid group and the second arc-extinguishing grid group. A gas pressure reduction area is provided at the end of the guide plates 21. The guide plates 21 are used to guide the residual arc and residual gas to the gas pressure reduction area.

[0058] In this embodiment, a cover plate 19 is further included. The cover plate 19 is arranged on the bracket 20, and the cover plate 19 is located between the first arc extinguishing chamber 26 and the second arc extinguishing chamber 27. The cover plate 19 is used to increase the isolation performance between the first arc extinguishing chamber 26 and the second arc extinguishing chamber 27.

[0059] In this embodiment, the angle between the first arc-extinguishing grid group and the second arc-extinguishing grid group is 3° to 5°.

[0060] In this embodiment, the angle between the first narrow slot structure 41 and the second narrow slot structure 42 is 20° to 180°.

[0061] The arc extinguishing system 3 in this embodiment is as follows Figure 1 The position shown is arranged with the moving contact system 2 and the stationary contact system 1 .

[0062] like Figure 2 and Figure 3 As shown, in the arc extinguishing system 3 of this embodiment, the area between the platform structure 29 of the static arc striking plate 28 and the arc striking silver point 10 of the arc contact 9 is the area where the arc is generated when the current is interrupted, that is, the arc generating area.

[0063] like Figures 4 to 13As shown, the arc extinguishing system 3 includes a bracket 20, a cover plate 19, a gas production plate 22, an arc extinguishing grid group 25, a dynamic arc striking plate 24, a static arc striking plate 28, a U-shaped magnetizing plate group 23, a first arc striking grid 31, a second arc striking grid 32, a baffle 30, and a guide plate 21.

[0064] In this embodiment, the cover plate 19 is installed on both sides of the bracket 20. The bracket 20 and the cover plate 19 together divide the arc extinguishing system 3 into two arc extinguishing chambers, namely the first arc extinguishing chamber 26 and the second arc extinguishing chamber 27, and the two arc extinguishing chambers are electrically isolated. An arc extinguishing grid group 25 is arranged in each arc extinguishing chamber, the end of the first arc-striking grid 31 is arranged at the uppermost side of the arc extinguishing grid group 25 of the first arc extinguishing chamber 26, and the end of the second arc-striking grid 32 is arranged at the lowermost side of the arc extinguishing grid group 25 of the second arc extinguishing chamber 27. The starting end of the first arc-striking grid 31 and the starting end of the second arc-striking grid 32 are stacked together, spanning the two arc extinguishing chambers, and are electrically connected. The movable arc-striking plate 24 is arranged at the uppermost side of the arc extinguishing grid group 25 of the second arc extinguishing chamber 27, and its part located outside the second arc extinguishing chamber 27 is a widened structure to enhance the arc-striking ability and heat capacity.

[0065] like Fig.13 As shown, the arc extinguishing grid group 25 in the first arc extinguishing chamber 26 and the arc extinguishing grid group 25 in the second arc extinguishing chamber 27 are arranged at a certain angle, and the angle is not less than 3°, preferably 3°~5°. With the above-mentioned angled arrangement, since the arc currents in the two arc extinguishing chambers have the same direction, the induced magnetic field between the two will attract each other, thereby solving the problem that the arc extinguishing grids are biased and burned after the arcs moving in the same direction in the two arc extinguishing chambers generate magnetic fields, and the utilization rate of the grids is low. At the same time, the thickness of the bracket 20 between the arc extinguishing grid group 25 in the first arc extinguishing chamber 26 and the arc extinguishing grid group 25 in the second arc extinguishing chamber 27 is increased, which ensures the mechanical strength of the bracket 20 and ensures that it is not damaged by the thrust of the high-pressure gas.

[0066] In this embodiment, the arc extinguishing grid group 25 in the first arc extinguishing chamber 26 and the arc extinguishing grid group 25 in the second arc extinguishing chamber 27 are arranged side by side, which is convenient for assembly.

[0067] In this embodiment, the support 20 has a guiding slope 33 structure, so that the incoming arc and high-temperature gas can easily change direction and enter the first arc extinguishing chamber 26 through the first arc entrance 34 and enter the second arc extinguishing chamber 27 through the second arc entrance 35. Fig.21As shown, the guide slope 33 of the bracket 20 cooperates with the baffle 30 to form narrow slot structures from small to large, and is dispersed into two narrow slot structures 40 from a single narrow slot structure 40, namely a first narrow slot structure 41 and a second narrow slot structure 42. The first narrow slot structure 41 and the second narrow slot structure 42 are arranged at a certain angle to the left and right, and the angle is between 20° and 180°. In this embodiment, taking the 2500A shell frame as an example, the angle is preferably 75°~95°.

[0068] It should be noted that, in the present embodiment, the angle between the first narrow slot structure 41 and the second narrow slot structure 42 depends on the distance between the first narrow slot structure 41 and the second narrow slot structure 42 (this distance depends on the grid width, and the grid width is limited by the overall size of the circuit breaker. When the grid width is larger, the angle will also become larger. Therefore, circuit breakers of different sizes will have different angles and the difference is relatively large) and the distance between the two and the narrow slot structure 40 (if the distance is too far, the arc extinguishing grid will be too far away from the arc contact, which is not conducive to the arc extinguishing grid attracting the arc; if the distance is too close, the airflow direction will rotate too quickly and the airflow resistance will be too large).

[0069] In this embodiment, the arc extinguishing grid group 25 (i.e., the first arc extinguishing grid group) of the first arc extinguishing chamber 26 and the arc extinguishing grid group 25 (i.e., the second arc extinguishing grid group) of the second arc extinguishing chamber 27 are arranged at a certain angle to the left and right, which is conducive to completing the arrangement of the narrow slot structure 40 dispersed into the first narrow slot structure 41 and the second narrow slot structure 42, reducing the angle between the first narrow slot structure 41 and the second narrow slot structure 42, and reducing gas resistance.

[0070] In this embodiment, the arc extinguishing grid group 25 in the lower part of the first arc extinguishing chamber 26 is a longer arc extinguishing grid; the arc extinguishing grid group 25 in the lower part of the second arc extinguishing chamber 27 is a shorter arc extinguishing grid, and the two are arranged at a certain angle or in parallel.

[0071] In this embodiment, the arc extinguishing grid group 25 in the upper part of the first arc extinguishing chamber 26 is a shorter arc extinguishing grid; the arc extinguishing grid group 25 in the upper part of the second arc extinguishing chamber 27 is a longer arc extinguishing grid, and the two are arranged at a certain angle or in parallel.

[0072] In this embodiment, baffles 30 are provided on both sides of the arc extinguishing grid group 25 in each arc extinguishing chamber to block the protruding parts on both sides of the arc extinguishing grid group 25 and respectively fit with both sides of the middle part of the first arc striking grid 31 and the second arc striking grid 32.

[0073] In this embodiment, the static arc-striking plate 28 is arranged at the bottom of the arc-extinguishing grid group 25 of the first arc-extinguishing chamber 26 of the bracket 20, and one end is connected to the static contact system 1 through a flexible connection line 36, and the two are electrically connected.

[0074] In this embodiment, the static arc-striking plate 28 has a platform structure 29 , which can contact the arc-striking silver point 10 of the arc contact 9 of the moving contact system 2 to achieve current conduction.

[0075] In this embodiment, a U-shaped magnetizing sheet group 23 is arranged below the platform structure 29. The two arms of the U-shaped arm of the U-shaped magnetizing sheet group 23 are arranged in the bracket 20, and are located on both sides of the arc-starting silver point 10 and the platform structure 29 (i.e., on both sides of the arc-generating area). The U-shaped magnetizing sheet group 23 is wrapped by an insulating sleeve 45 below, which can be electrically isolated from the static arc-starting plate 28, and cooperates with the pad of the static contact system 1 to fix the position of the platform structure 29.

[0076] In this embodiment, a narrow slot structure 40 is formed at the front end of the bracket 20, and gas production plates 22 are provided on both sides of the narrow slot structure 40. Figure 2 , Figure 4 and Figure 6 As shown, the gas production plate 22 is located on both sides of the platform structure 29 of the static arc-starting plate 28 and covers the entire movement path of the arc-starting silver point 10, and cooperates closely with the arc contact 9 to form a narrow gap structure.

[0077] like Figures 16 to 20 As shown, the bracket 20 has a guide slope 33 structure, which makes it easy for the incoming arc and high-temperature gas to change direction and enter the first arc extinguishing chamber 26 through the first arc entrance 34 and enter the second arc extinguishing chamber 27 through the second arc entrance 35.

[0078] like Fig.21 As shown, the guide slope 33 of the bracket 20 cooperates with the baffle 30 to form narrow slot structures from small to large, and is dispersed from a single narrow slot structure 40 into two narrow slot structures 40, namely a first narrow slot structure 41 and a second narrow slot structure 42. The first narrow slot structure 41 and the second narrow slot structure 42 are arranged at a certain angle to the left and right, and the angle is between 20° and 180°.

[0079] like Figure 4 and Figure 6 As shown, the front end of the bracket 20 has a cylindrical structure 47 and a groove structure 39, which can cooperate with the moving contact system 2, wherein the cylindrical structure 47 at the front end of the bracket 20 fits with the cylindrical structure of the moving contact cover of the moving contact system 2, and the groove structure 39 cooperates with the boss structure of the moving contact cover, thereby increasing the resistance of the airflow to escape outward, preventing the airflow from moving from the arcing area toward the moving contact system 2, and isolating the arcing area between the arcing silver point 10 of the arc contact 9 and the platform structure 29 of the static arcing plate 28 from other conductive parts of the moving contact system 2.

[0080] like Figure 5As shown, guide plates 21 are provided at the ends of the arc extinguishing grid groups 25 in the first arc extinguishing chamber 26 and the second arc extinguishing chamber 27. The guide plates 21 have a certain thickness. In this embodiment, the thickness of the guide plates 21 is preferably 5-8 mm. By using a hole structure with a certain thickness, the airflow direction is constrained to the direction of the hole, so that the movement direction of the residual arc and the high-temperature gas can be controlled, and an appropriate space is left on the outside of the guide plate 21 as a gas pressure decompression area, which is beneficial to gas discharge and prevents back breakdown.

[0081] In this embodiment, the platform structure 29 may be welded with materials such as silver dots to cooperate with the arc-starting silver dots 10 to reduce the contact resistance between the static arc-starting plate 28 and the arc contact 10 and enhance conductivity.

[0082] In this embodiment, the U-shaped magnetizing sheet group 23 can be made of low magnetic resistance materials such as silicon steel sheets to enhance magnetic conductivity.

[0083] In this embodiment, a folded metal mesh or other anti-ionization measures may be installed in the space outside the guide plate 21 to prevent the residual arc from further spreading outward.

[0084] In this embodiment, the arc extinguishing grid group 25 is a symmetrically cut grid or an asymmetrically cut grid. The shape of the arc extinguishing grid can be appropriately changed according to the voltage or current level requirements; a non-cut arc extinguishing grid can be used, which has a high heat capacity and a good deionization effect, making the arc easier to extinguish. Asymmetrically cut grids can also be arranged alternately to lengthen the arc, increase the arc voltage, and make the arc easier to extinguish.

[0085] In this embodiment, the initial end width of the static arc-striking plate 28 covers the entire width of the arc-extinguishing system 3 and gradually changes with the inclined structure at the bottom of the first arc-entry opening 34 of the bracket 20 until the end is the same width as the arc-extinguishing grid group 25 of the first arc-extinguishing chamber 26.

[0086] In this embodiment, the initial end of the movable arc-striking plate 24 gradually changes with the inclined structure at the top of the second arc entrance port 35 of the bracket 20 until the end is the same width as the arc-extinguishing grid group 25 of the second arc-extinguishing chamber 27; the movable arc-striking plate 24 is electrically connected to or close to the arc contact 9 in the disconnected position to guide the arc path.

[0087] like Figures 22 to 26 As shown, in another embodiment, the front ends of the first arc-striking grid 31 and the second arc-striking grid 32 of the arc-extinguishing system 3 extend to the interior of the bracket 20. The two have the same shape and structure, and are arranged to fit together by 180° rotation. The front ends form a U-shaped structure to pull the arc to move into the interior of the arc-extinguishing system 3.

[0088] like Fig.24As shown, the front ends of the first arc-starting grid 31 and the second arc-starting grid 32 have arc-starting cutouts 48, and the directions of the arc-starting cutouts 48 correspond to the entrance angles of the first arc-entry opening and the second arc-entry opening, respectively. Fig.25 As shown, it is more conducive for the arc to move into the first arc entrance opening 34 and the second arc entrance opening 35. At the same time, the first arc-starting grid 31 and the second arc-starting grid 32 adopt a superimposed structure to increase the heat capacity and enhance the deionization effect.

[0089] The operating principle of the arc extinguishing system of this embodiment is as follows:

[0090] like Figures 14 to 21 As shown, it is a schematic diagram of the movement direction of the arc in the arc extinguishing system 3 when the arc is generated between the arc-strike silver point 10 of the arc contact 9 and the static arc-strike plate 17. When the arc is generated, the high-temperature arc promotes the decomposition of the gas-producing plates 22 on both sides of the arc-strike silver point 10 of the arc contact 9, generates a particle airflow, forms a gas blowing effect, and promotes the arc to enter the first arc extinguishing chamber 26 and the second arc extinguishing chamber 27. At the same time, the U-shaped magnetizing plate group 23 on both sides of the arc-strike silver point 10 concentrates and enhances the current induced magnetic field flowing through the static arc-strike plate 28. According to the Lorentz force analysis, it can be obtained that the magnetic field formed between the two arms of the U-shaped arm of the U-shaped magnetizing plate group 23 has a Lorentz force direction on the arc current, which is toward the inside of the arc extinguishing system 3, regardless of the current direction, forming a non-polar enhanced magnetic blowing effect. The arc and the high-temperature gas are guided by the guide slope 33 and enter the first arc extinguishing chamber 26 through the first arc inlet 34 respectively, as shown in FIG. Figures 16-18 As shown, the arc enters the second arc extinguishing chamber 27 through the second arc entrance 35, as shown in FIG. Figures 18 to 20 shown.

[0091] Fig.21 The schematic diagram of the arc and airflow movement direction of the arc entrance of the arc extinguishing system is as follows. After the arc is generated in the arcing zone in the narrow slot structure 40, it passes through the first narrow slot structure 41 of the first arc entrance 34 and the second narrow slot structure 42 of the second arc entrance 35, and finally enters the arc extinguishing chamber. As the arc moves into the arc extinguishing system 3, the space gradually increases, reducing the arc and airflow resistance. Through the air blowing effect, the arc and high-temperature gas are accelerated to enter the arc extinguishing chamber. Multiple narrow slot structures 40 constrain the arc diameter, reduce the arc energy, and constrain the arc path at the same time. The arc is gradually elongated during the movement in the narrow slot structure 40, and then dispersed into the two gradually widening first narrow slot structures 41 and the second narrow slot structure 42, which enhances the diffusion and cooling of the arc and improves the ionization effect. The elongated arc finally enters the arc extinguishing grid group 25 of each arc extinguishing chamber, and the arc is extinguished through the cutting and cooling of the arc extinguishing grid.

[0092] Fig. 27Schematic diagram of the current state at the initial stage of breaking. At the moment of breaking, the arc-starting silver point 10 of the arc contact 9 is still in contact with the platform structure 29 of the static arc-starting plate 28 to achieve the function of conducting current, so the arc has not yet been generated. At this time, the current direction is as follows Fig. 27 shown.

[0093] Fig.28 The figure is a schematic diagram of the current and arc movement at the initial stage of contact opening. At this time, the moving contact system 2 drives the arc contact 9 to rotate clockwise, and the arc is generated between the arc-starting silver point 10 of the arc contact 9 and the platform structure 29 of the static arc-starting plate 28. The arc is in the narrow slit structure 40 on both sides of the arc contact 9. The high temperature causes the gas-producing plate 22 to crack and generate gas, forming a gas blowing effect. Under the action of the gas blowing, the arc moves toward the inside of the arc extinguishing system 3. The U-shaped magnetizing plate group 23 gathers the induced magnetic field in the "×" direction of the current through its "U-shaped" bottom, and forms an enhanced magnetic field in the "·" direction between the two arms of its "U-shaped" shape, exerting a Lorentz force on the arc to move toward the inside of the arc extinguishing system 3, forming a magnetic blowing effect, where "×" represents the tail of an arrow, that is, the direction perpendicular to the page direction, and "·" represents an arrow, that is, the direction perpendicular to the page direction.

[0094] Fig.29 This is a schematic diagram of current and arc movement in the middle of breaking. At this time, the moving contact system 2 gradually opens, and the generated arc moves to the first arc extinguishing chamber 26 through the first arc inlet 34 and to the second arc extinguishing chamber 27 through the second arc inlet 35 under the effect of air blowing and magnetic blowing.

[0095] Fig.30 This is a schematic diagram of the current and arc movement in the first arc extinguishing chamber 26 at the end of the breaking period; Fig.31 This is a schematic diagram of the current and arc movement in the second arc extinguishing chamber 27 at the end of the breaking period. At this time, the moving contact system 2 is basically fully opened, the arc contact 9 is electrically connected to the moving arc-starting plate 24, or the distance is small, it is easy to form an arc, so that the arc contact 9 and the moving arc-starting plate 24 have basically the same potential.

[0096] In this embodiment, the arc entering the first arc extinguishing chamber 26 is gradually blown into the first arc extinguishing chamber 26 by the action of gas blowing and magnetic blowing, and gradually elongated by the action of the static arc striking plate 28 and the first arc striking grid 31, and is cut by the arc extinguishing grid group 25. Since the static arc striking plate 28 is electrically connected to the static contact system 1, the resistance to arc movement and elongation is greatly reduced.

[0097] In this embodiment, the arc entering the second arc extinguishing chamber 27 is gradually blown into the second arc extinguishing chamber 27 by the action of air blowing and magnetic blowing, and gradually elongated by the second arc striking grid 32 and the moving arc striking plate 24, and is cut by the arc extinguishing grid group 25. Since the arc contact 9 and the moving arc striking plate 24 have basically the same potential, the resistance to arc movement and elongation is greatly reduced. The first arc striking grid 31 is electrically connected to the second arc striking grid 32, which also reduces the resistance to arc movement and elongation. The arcs inside the two arc extinguishing chambers have opposite current directions, and the Lorentz force between the two is mutually attractive, which can reduce the asynchronism of the arcs inside the two chambers and improve the simultaneous utilization of the grids. At the same time, the arc is formed in series inside the two arc extinguishing chambers, realizing the arc current series connection of the static arc-starting plate 28 → arc-extinguishing grid group 25 → first arc-starting grid 31 → second arc-starting grid 32 → arc-extinguishing grid group 25 → moving arc-starting plate 24, realizing a small volume, multi-grid series structure, improving the ability to break high-voltage arcs, and reducing the volume of the arc extinguishing system 3. The narrow slit structure on both sides of the arc contact 9 avoids the situation where the electric field is too dispersed due to excessive space, and the arc electric field is more concentrated, constraining the arc path, improving the utilization rate of the grid, improving the deionization effect, and helping to reduce the arc energy.

[0098] At the same time, the arc contact 9 cooperates with the narrow slot structure 40, and the arc is gradually stretched during the movement in the narrow slot structure 40, and then dispersed into two gradually widening first narrow slot structures 41 and second narrow slot structures 42, thereby enhancing the diffusion and cooling of the arc and improving the deionization effect. Multiple narrow slot structures 40 constrain the arc diameter, reduce the arc energy, and constrain the arc path at the same time. The space behind the narrow slot structure 40 gradually becomes larger, reducing the resistance to the arc movement, so that the arc can be stretched by the narrow slot structure 40 and is easier to enter the arc extinguishing grid and be cut by the arc extinguishing grid. The longer arc extinguishing grids and the shorter arc extinguishing grids in the first arc extinguishing chamber 26 and the second arc extinguishing chamber 27 are arranged in parallel, and the first arc entrance opening 34 and the second arc entrance opening 35 correspond to the longer arc extinguishing grids respectively, which enhances the attraction of the arc extinguishing grids to the arc at the arc entrance opening position, and at the same time prolongs the residence time of the initial arc at the arc entrance opening of each arc extinguishing chamber on the arc extinguishing grid, and is cut by the arc extinguishing grid synchronously with the delayed arc stretched by the first arc-starting grid 31 and the second arc-starting grid 32, thereby improving the simultaneous utilization rate of the arc extinguishing grids.

[0099] The present invention provides an arc extinguishing system, which is applied to higher rated working voltages, can effectively reduce the size of the circuit breaker, has the ability to single-pole interrupt the full voltage short-circuit current, and greatly reduces the arcing distance. The narrow slit structure of the arc extinguishing system adopts a structure in which a single narrow slit is dispersed into two narrow slits, which maximizes the arc length within a limited volume. The multi-narrow slit structure can compress the arc diameter, constrain the arc path, improve the grid utilization rate, and enhance the ion elimination effect. The arc extinguishing system of the present invention can be coordinated with the contact system to isolate the contact system from the arc extinguishing system. The arc diameter is constrained by the narrow slit structure, so that the arc electric field is more concentrated, which is conducive to constraining the arc path and easily forming a more concentrated induced magnetic field. In addition, the present invention adopts the method of enhancing magnetic blowing and air blowing to improve the breaking effect of the critical load current of the circuit breaker under DC conditions, and has the advantage of non-polarity. The arc extinguishing system of the present invention can be applied to higher AC rated working voltages and has a higher breaking capacity.

[0100] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0101] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An arc extinguishing system, wherein the arc extinguishing system and a contact system form a circuit breaker, wherein the contact system comprises a moving contact system and a stationary contact system, wherein the moving contact system comprises an arcing contact, wherein: The arc extinguishing system comprises a bracket, a narrow slot structure arranged in front of the bracket and accommodating the arc contact, and an arc extinguishing chamber arranged behind the bracket; The arc extinguishing chamber comprises a first arc extinguishing chamber and a second arc extinguishing chamber, the first arc extinguishing chamber and the second arc extinguishing chamber are electrically isolated from each other; a first arc extinguishing grid group is arranged inside the first arc extinguishing chamber, and a second arc extinguishing grid group is arranged inside the second arc extinguishing chamber; The narrow slot structure is a narrow slot-shaped hollow structure, and the narrow slot structure is separated into a first narrow slot structure and a second narrow slot structure from one end to the other end. The first narrow slot structure and the second narrow slot structure are arranged at an angle, and the first narrow slot structure and the second narrow slot structure are respectively oriented toward the first arc-extinguishing grid group and the second arc-extinguishing grid group to form two arc-extinguishing channels; the narrow slot structure is used to make the arc generated at the arc contact reach the first arc-extinguishing grid group and the second arc-extinguishing grid group along the two arc-extinguishing channels to achieve arc extinguishing after the circuit is disconnected; The arc extinguishing system further comprises a first arc striking grid and a second arc striking grid; The end of the first arc-striking grid is arranged at the top of the first arc-extinguishing grid group, the end of the second arc-striking grid is arranged at the bottom of the second arc-extinguishing grid group, and the starting end of the first arc-striking grid is overlapped with the starting end of the second arc-striking grid and is electrically connected; The first arc-starting grid and the second arc-starting grid are used to direct the arc to the first arc-extinguishing grid group and the second arc-extinguishing grid group, respectively.

2. An arc extinguishing system according to claim 1, characterized in that: It also includes a movable arc-striking plate, which is arranged on the top of the second arc-extinguishing grid plate group and is used to guide the arc to the second arc-extinguishing grid plate group.

3. An arc extinguishing system according to claim 1, characterized in that: It also includes a static arc-striking plate, which is arranged at the bottom of the first arc-extinguishing grid group and is used to connect the static contact system.

4. An arc extinguishing system according to claim 3, characterized in that: The static arc-starting plate is provided with a platform structure, and the platform structure is used to form an arc-starting zone between the arc contact and the platform structure after contacting the arc-starting silver point of the arc contact, and the arc-starting zone is a region where an arc is generated.

5. An arc extinguishing system according to claim 4, characterized in that: A U-shaped magnetizing plate group is arranged below the platform structure, and the U-shaped magnetizing plate group includes a U-shaped arm, and the U-shaped arm is arranged on the bracket and the opening of the U-shaped arm faces the narrow gap structure. The arc generating zone is located within the range of the U-shaped arm, and the U-shaped magnetizing plate group is used to form an induced magnetic field around the arc generating zone, so that the arc generated in the arc generating zone moves toward the direction of the narrow gap structure under the action of the magnetic force of the induced magnetic field.

6. An arc extinguishing system according to claim 1, characterized in that: A guide plate is provided at the end of the first arc-extinguishing grid group and the end of the second arc-extinguishing grid group. A gas pressure reduction area is provided at the end of the guide plate. The guide plate is used to guide the residual arc and residual gas to the gas pressure reduction area.

7. An arc extinguishing system according to claim 1, characterized in that: It also includes a cover plate, which is arranged on the bracket and located between the first arc extinguishing chamber and the second arc extinguishing chamber, and the cover plate is used to increase the isolation performance between the first arc extinguishing chamber and the second arc extinguishing chamber.

8. An arc extinguishing system according to claim 1, characterized in that: The first arc-extinguishing grid group and the second arc-extinguishing grid group are arranged at an angle, and the angle between the first arc-extinguishing grid group and the second arc-extinguishing grid group is 3° to 5°.

9. The arc extinguishing system according to claim 1, characterized in that: The included angle between the first narrow slit structure and the second narrow slit structure is 20° to 180°.

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