Buffer device and method for high-capacity circuit breaker

Abstract

The invention relates to the field of circuit breakers, in particular to a buffer device and method for a high-capacity circuit breaker. Comprising a first buffer unit, a second buffer unit and a limiting unit, comprising a first buffer unit, a second buffer unit and a limiting unit, the first buffer unit is used for being in contact with a moving part in an opening spring device of the circuit breaker in the opening process of the circuit breaker so as to provide buffer of a first stage; the second buffer unit is used for being arranged opposite to a movable guide rod of an arc extinguish chamber of the circuit breaker in the opening process of the circuit breaker so as to provide buffer of a second stage; and the limiting unit is used for being in transmission fit with a main shaft of the circuit breaker so as to stop the opening motion of the circuit breaker. According to the buffer device disclosed by the invention, through a sectional buffer design, the impact on the internal mechanical structure of the circuit breaker at the last stage of opening is reduced while the breaking performance of the circuit breaker is maintained, and the overall service life of equipment is effectively prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of circuit breakers, in particular to a buffering device and method for a high-capacity circuit breaker. BACKGROUND

[0002] A high-capacity circuit breaker is a key protection device in a power system, and the circuit breaker has a high requirement for the tripping characteristics, especially the initial tripping speed, which is directly related to the rapid extinction of arc and the reliable breaking capacity of short-circuit fault, so the industry generally pursues a higher initial tripping speed.

[0003] However, a higher tripping speed, while ensuring the breaking capacity, will also cause a severe impact on the internal mechanical structure of the circuit breaker, which not only may cause damage to the transmission components and shorten the service life of the equipment, but also easily causes overshoot and rebound at the end of the tripping movement, thereby interfering with the stable separation of the contacts and reducing the actual breaking performance and operation reliability.

[0004] To alleviate the above problems, the prior art usually provides a buffering device in the circuit breaker, such as a hydraulic buffer, a pneumatic damper or an elastic element installed at the end of the transmission chain or the moving component, so as to consume part of the kinetic energy and reduce the impact and rebound at the end of tripping.

[0005] However, the existing buffering scheme is usually a whole deceleration at the end of tripping, which is difficult to meet the two problems of high initial speed and low end impact, and if the buffering is intervened too early, the speed will be weakened, affecting the breaking capacity, and if the buffering is insufficient, the end overshoot cannot be effectively inhibited. SUMMARY

[0006] In view of the problems mentioned in the prior art, the present application provides a buffering device and method for a high-capacity circuit breaker, which realizes the initial fast tripping and smooth stopping of the tripping movement of the circuit breaker by using multiple buffering units in cooperation, so as to solve the problems in the background art.

[0007] In order to achieve the above-mentioned purposes, the present application adopts the following technical solutions: The buffering device for a high-capacity circuit breaker comprises a first buffering unit, a second buffering unit and a limiting unit. The first buffering unit is used to contact the moving part in the tripping spring device of the circuit breaker during the tripping process of the circuit breaker, so as to provide the first-stage buffering. The second buffering unit is used to be arranged opposite to the moving guide rod of the arc-extinguishing chamber of the circuit breaker during the tripping process of the circuit breaker, so as to provide the second-stage buffering. The limiting unit is used to cooperate with the main shaft transmission of the circuit breaker, so as to terminate the tripping movement of the circuit breaker. As a further improvement of the present application, the first buffering unit comprises a buffering spring, and the buffering spring is arranged on the tripping spring device.

[0008] As a further improvement of the application, the first buffer unit further comprises a washer arranged between the buffer spring and the moving part in the opening spring device.

[0009] As a further improvement of the application, the second buffer unit comprises a buffer fixed on the lower support of the circuit breaker through a mounting plate; the buffer is in contact with the moving contact rod of the arc extinguishing chamber to realize buffering.

[0010] As a further improvement of the application, the second buffer unit further comprises a fixing nut for adjusting the buffering stroke of the buffer.

[0011] As a further improvement of the application, the number of the buffers is plural, and each buffer is arranged corresponding to one phase of the circuit breaker.

[0012] As a further improvement of the application, the limiting unit comprises limiting screws in contact with the rollers connected with the main shaft transmission.

[0013] As a further improvement of the application, the number of the limiting screws is 2-5.

[0014] As a further improvement of the application, the first buffer unit, the second buffer unit and the limiting unit work in sequence during the opening process of the circuit breaker.

[0015] The application provides a buffering method of a large-capacity circuit breaker, based on the buffering device of the large-capacity circuit breaker, comprising the following steps: Drive the circuit breaker to open, so that the moving contact rod of the arc extinguishing chamber starts to move, at this time, the first buffer unit and the second buffer unit do not participate in buffering; When the circuit breaker is opened to a first preset distance, the first buffer unit is triggered to be in contact with the moving part in the opening spring device and provide the first-stage buffering; When the circuit breaker is opened to a second preset distance, the second buffer unit is triggered to be in contact with the moving contact rod of the arc extinguishing chamber and provide the second-stage buffering; When the main shaft transmission of the circuit breaker rotates to a preset end position, the limiting unit is triggered to be in contact with the main shaft transmission to terminate the opening movement of the circuit breaker.

[0016] Compared with the prior art, the application has the following technical effects: The buffer device of the application fundamentally solves the demand of large-capacity circuit breaker for high initial opening speed and low final impact by sectional buffer design; specifically, by setting the first buffer unit, the second buffer unit and the limiting unit, the decoupling and collaborative control of the opening process are successfully realized, in the initial opening stage, the first buffer unit, the second buffer unit and the limiting unit do not work, so that a higher initial opening speed can be obtained, ensuring the arc breaking capacity of the circuit breaker, then the first buffer unit works at the first preset position to reduce the opening kinetic energy, followed by the second buffer unit working to further dissipate the remaining opening kinetic energy and reduce the opening speed to a safe range; finally, the limiting unit is used to realize mechanical stop and complete the opening work; the whole process can maintain the breaking performance of the circuit breaker while reducing the impact on the internal mechanical structure of the circuit breaker at the end of the opening, effectively prolonging the overall life of the equipment.

[0017] The first buffer unit of the application includes a buffer spring and cooperates with a gasket, which is simple and reliable in structure, and realizes control of the buffer starting point, and the gasket ensures that the buffer spring contacts the moving part in the opening spring device after the circuit breaker reaches the first preset distance, thereby ensuring that the opening speed is not affected; the second buffer unit adopts a buffer fixed to the lower support, and the stroke of the buffer can be adjusted by a fixing nut, further improving flexibility, and the damping force of the buffer can be adjusted according to the actual working conditions and buffer requirements of different types of circuit breakers to achieve the best buffer effect, and the buffer is configured as multiple and corresponding to the number of phases of the circuit breaker, which not only enhances the buffer reliability, but also ensures the synchronization and stability of the movement of the moving contact of each phase, improving the stability and consistency of the breaking of the circuit breaker; in addition, the limiting unit of the application adopts a limiting screw and cooperates with a roller associated with the main shaft transmission to realize the termination of the opening movement of the circuit breaker, and multiple limiting screws can be used to increase the buffering effect and further improve the use reliability. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a structural front view of the buffer device of the application; Figure 2 is a structural right view of the buffer device of the application; Figure 3 is a structural top view of the buffer device of the application; Figure 4 is a working timing diagram of the buffer device of the application.

[0019] Reference: 1, operating mechanism; 2, limit crank arm; 3, roller; 4, main shaft transmission; 5, limit screw; 6, insulating pull rod; 7, crank arm; 8, connecting head; 9, lower support; 10, mounting plate; 11, fixing nut; 12, buffer; 13, vacuum interrupter; 13.1, interrupter moving guide rod; 14, opening spring device; 15, buffer spring; 16, washer. DETAILED DESCRIPTION

[0020] Hereinafter, only certain exemplary embodiments are simply described. As those skilled in the art can recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the present application. Therefore, the drawings and the description are considered to be exemplary in nature rather than limiting.

[0021] In the description of the present application, it needs to be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0022] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0023] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral; it can be mechanical connection, or electrical connection, or communication; it can be directly connected, or indirectly connected through intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0024] In the present application, unless specifically stated and limited otherwise, the first feature is "on" or "under" the second feature can include that the first and second features are in direct contact, or can include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature is "on", "above" and "over" the second feature includes that the first feature is directly above and obliquely above the second feature, or only means that the first feature is higher in horizontal height than the second feature. The first feature is "under", "below" and "underneath" the second feature includes that the first feature is directly above and obliquely above the second feature, or only means that the first feature is lower in horizontal height than the second feature.

[0025] It should be understood that the terms "comprises" and "comprising" when used in this specification and the following claims, indicate the presence of the described features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0026] It should also be understood that the terms used in the present application specification are only for the purpose of describing particular embodiments and are not intended to limit the present application. As used in the present application specification and the following claims, the singular forms "a", "an" and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0027] It should be further understood that the term "and / or" used in the present application specification and the following claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0028] Various structural diagrams according to the disclosed embodiments of the present application are shown in the accompanying drawings. These drawings are not drawn to scale, in which certain details are exaggerated for the purpose of clarity and some details may be omitted. The shapes of various regions, layers shown in the drawings and their relative sizes and positional relationships may deviate in actuality due to manufacturing tolerances or technical limitations, and regions / layers with different shapes, sizes, relative positions can be additionally designed by those skilled in the art according to actual needs.

[0029] Referring to Figure 1 , Figure 2 and Figure 3 , the present embodiment proposes a buffering device of a large-capacity circuit breaker, comprising a first buffering unit, a second buffering unit and a limiting unit; The first buffering unit is used to contact the moving part in the circuit breaker opening spring device 14 during the opening process of the circuit breaker, to provide the first stage of buffering; The second buffering unit is arranged opposite to the moving contact rod 13.1 of the arc extinguishing chamber of the circuit breaker during the tripping process of the circuit breaker to provide a second stage of buffering. The limiting unit is used in cooperation with the main shaft transmission 4 of the circuit breaker to terminate the tripping movement of the circuit breaker.

[0030] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0031] Referring to Figure 1 The circuit breaker of the embodiment is composed of an operating mechanism 1, a main shaft transmission 4, an insulating pull rod 6, a crank arm 7, a lower support 9, a moving contact rod 13.1 of an arc extinguishing chamber, a tripping spring device 14, etc., to complete the tripping movement of the circuit breaker.

[0032] The operating mechanism 1 in the embodiment is a power source of the tripping movement, and the operating mechanism 1 is usually a mechanism composed of a spring, a connecting rod and a tripping device, which outputs mechanical movement to the main shaft transmission 4, wherein the main shaft transmission 4 is connected to a limiting crank arm 2, which rotates synchronously with the main shaft transmission 4, and a roller 3 is installed at the end of the limiting crank arm 2 in order to improve the contact performance and reduce wear; the connecting rod mechanism for converting the rotary movement into linear movement is connected to the main shaft transmission 4, and the connecting rod mechanism includes the insulating pull rod 6 and the crank arm 7, one end of the insulating pull rod 6 is hinged to the output arm of the main shaft transmission 4, and the other end is connected to the moving contact rod 13.1 of the arc extinguishing chamber through a connecting head 8, when the main shaft transmission 4 rotates, the power is transmitted through the crank arm 7 and the insulating pull rod 6, and finally the linear movement of the moving contact rod 13.1 vertically upward is realized, so as to drive the moving contact and the static contact in the vacuum arc extinguishing chamber 13 to separate.

[0033] The moving part in the tripping spring device 14 in the embodiment is a main tripping spring, after the operating mechanism 1 is unlocked, the elastic potential stored in the tripping spring device 14 is released, and the main tripping spring in the tripping spring device 14 acts, and the action is finally applied to the main shaft transmission 4 to provide a continuous rotary torque.

[0034] The above components constitute the transmission chain of the tripping of the circuit breaker, and the first buffering unit, the second buffering unit and the limiting unit are arranged on the basis of the transmission chain in the embodiment.

[0035] The first buffering unit of the embodiment comprises a buffering spring 15, which is specifically mounted on the opening spring device 14, and the axis direction of the buffering spring 15 is consistent with the movement direction of the moving part inside the opening spring device 14; in addition, a gasket 16 is arranged between the buffering spring 15 and the moving part in the opening spring device 14, wherein the thickness of the gasket 16 is adjustable; specifically, in the initial opening stage, the moving part of the opening spring device 14 is in action, and within the initial distance, the gasket 16 arranged can make the moving part in the opening spring device 14 and the buffering spring 15 have a gap, so the two are not in contact, at this time, the buffering spring 15 does not work, only the opening spring device 14 works; when the moving part in the opening spring device 14 completely adheres and starts to compress the gasket 16 and the buffering spring 15, the first buffering unit starts to work, at this time, the reverse elastic force generated by the buffering spring 15 can offset part of the driving force of the opening spring device 14, so as to realize the first-stage buffering.

[0036] The second buffering unit of the embodiment is a buffer 12, which preferably adopts any one of a hydraulic buffer, an oil-gas hybrid buffer or a high-performance elastomer, which can be selected according to the use scene; as shown in Figure 2 and Figure 3 , the buffer 12 is mounted on the mounting plate 10, the mounting plate 10 is fixedly mounted on the lower support 9 of the circuit breaker by means of bolts and the like, and the lower support 9 in the embodiment is a steel structure for supporting the vacuum arc-extinguishing chamber 13 and the like; the buffer 12 in the embodiment is arranged in alignment with the lower end of the arc-extinguishing chamber moving guide rod 13.1. Specifically, when the arc-extinguishing chamber moving guide rod 13.1 has not reached this position during the opening movement, the buffer 12 does not work, when the arc-extinguishing chamber moving guide rod 13.1 contacts and starts to compress the buffer 12 during the opening movement, the second buffering unit starts to work, the buffer 12 generates a strong damping force through the internal medium (oil or gas) thereof, which directly acts on the arc-extinguishing chamber moving guide rod 13.1, so as to consume the remaining opening kinetic energy, and realize the second-stage buffering.

[0037] In order to optimize the buffering effect, the buffering stroke of the buffer 12 is adjustable, by screwing the fixing nut 11, the axial position of the buffer 12 relative to the mounting plate 10 can be changed, so as to adjust the contact timing and compression stroke of the buffer 12 and the arc-extinguishing chamber moving guide rod 13.1, to adapt to different buffering strength requirements; in addition, for a three-phase circuit breaker, the buffer 12 is preferably mounted on the lower support 9 of each phase as shown in Figure 3 , which can provide independent and balanced buffering for each phase.

[0038] The limiting unit in the embodiment comprises at least one limiting screw 5, as shown in Figure 1As shown, the end face position of the limit screw 5 is set to the maximum opening angle allowed by the design when the main shaft drive 4 rotates. Specifically, when the opening movement is about to end, the main shaft drive 4 will drive the connected limit crank arm 2 and roller 3 to rotate together to the end position. The roller 3 will come into contact with the limit screw 5. Since the limit screw 5 is fixed, it will restrict the roller 3 from moving forward, thereby forcibly preventing the limit crank arm 2 and the main shaft drive 4 from rotating further. At this point, the entire opening movement is stopped. In addition, in order to improve the reliability of long-term use, this embodiment can set two or even more limit screws 5, and set multiple limit screws 5 on the movement trajectory of the limit crank arm 2 to form a stable structure with multiple points of contact.

[0039] See Figure 4 The usage process in this embodiment includes: first, the tripping command is triggered, the operating mechanism 1 is unlocked, and the corresponding... Figure 4 At time t1, the circuit breaker is in the initial opening stage. The energy stored in the opening spring device 14 is released instantaneously, causing the moving parts of the opening spring device 14 to move. At this time, due to the gap created by the washer 16, the opening spring device 14 and the buffer spring 15 are not in contact. The driving force generated by the moving parts of the opening spring device 14 will drive the main shaft drive 4 to rotate, thereby driving the arc-extinguishing chamber moving guide rod 13.1 to move. As the main shaft drive 4 rotates, it will drive the arc-extinguishing chamber moving guide rod 13.1 to move. At this time, after the moving parts in the opening spring device 14 have completed their stroke, they will begin to compress the washer 16 and the buffer spring 15. The buffer spring 15 will counteract part of the thrust from the opening spring, thus achieving the first stage of buffering. Figure 4 At time t2.

[0040] When the arc-extinguishing chamber moving guide rod 13.1 reaches the predetermined position, it begins to contact and compress the buffer 12. Utilizing the damping force provided by the buffer 12, the remaining tripping kinetic energy is dissipated, achieving the second stage of buffering. This reduces the tripping speed to a very low level. Figure 4 At time t3; when the main shaft drive 4 rotates to its limit angle, the roller 3 on the limit crank arm 2 contacts the limit screw 5, and the limit screw 5 limits the movement, causing the main shaft drive 4 to stop. This completes the entire circuit breaker opening and closing motion. Figure 4 At time t4.

[0041] The foregoing merely illustrates the principles of the application and application of its leading features. This application is not limited to the exact details shown above and described herein, and obvious modifications will occur to those skilled in the art upon reading the foregoing description. Therefore, the scope of the application is not to be determined by such specific details but only by the claims which follow, and any equivalents thereof. Any figure reference herein shall not be construed as limiting the scope of the claims to which it is directed.

[0042] Furthermore, it should be understood that although the description above relates to embodiments, not every embodiment contains only one independent technical solution, and the description above is only for the sake of clarity, and those skilled in the art should understand the description as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that those skilled in the art can understand. The above is only to illustrate the technical idea of the present application, and cannot limit the protection scope of the present application. Any modification made on the basis of the technical solutions according to the present application falls within the protection scope of the claims of the present application.

Claims

1. A cushioning device for a bulk circuit breaker, characterized in that The first buffer unit, the second buffer unit and the limiting unit are included. The first buffer unit is used to contact with the moving part in the circuit breaker opening spring device (14) during the circuit breaker opening process to provide the first stage of buffer. The second buffer unit is used to be arranged opposite to the moving contact of the arc extinguishing chamber (13.1) during the circuit breaker opening process to provide the second stage of buffer. The limiting unit is used to cooperate with the main shaft transmission (4) of the circuit breaker to terminate the circuit breaker opening movement.

2. The damping device for bulk circuit breakers according to claim 1, characterized in that The first buffer unit includes a buffer spring (15) arranged on the opening spring device (14).

3. A damping device for a high capacity circuit breaker according to claim 2, characterized in that The first buffer unit further includes a washer (16) arranged between the buffer spring (15) and the moving part in the opening spring device (14).

4. The damping device for bulk circuit breakers of claim 1, wherein The second buffer unit includes a buffer (12) fixedly arranged on the lower support (9) of the circuit breaker through a mounting plate (10); the buffer (12) is used to realize the buffer by contacting with the moving contact of the arc extinguishing chamber (13.1).

5. The damping device of a bulk circuit breaker according to claim 4, characterized in that The second buffer unit further includes a fixing nut (11) used to adjust the buffer stroke of the buffer (12).

6. The damping device of a bulk circuit breaker according to claim 4, wherein The number of the buffers (12) is multiple, and each buffer (12) corresponds to one phase of the circuit breaker.

7. The damping device of a bulk circuit breaker according to claim 1, wherein The limiting unit includes a limiting screw (5) contacting with the roller (3) connected with the main shaft transmission (4).

8. The damping device of a bulk circuit breaker according to claim 7, characterized in that The number of the limiting screws (5) is 2-5.

9. The damping device of a bulk circuit breaker according to claim 1, wherein During the circuit breaker opening process, the first buffer unit, the second buffer unit and the limiting unit work in sequence.

10. A method of damping a bulk circuit breaker, based on the damping device of any one of claims 1 to 9, characterized in that The method includes the following steps: Drive the circuit breaker to open, and the moving contact of the arc extinguishing chamber (13.1) starts to move, at this time, the first buffer unit and the second buffer unit do not participate in the buffer; When the circuit breaker is opened to the first preset distance, the first buffer unit is triggered to contact with the moving part in the opening spring device (14) and provide the first stage of buffer; When the circuit breaker is opened to the second preset distance, the second buffer unit is triggered to contact with the moving contact of the arc extinguishing chamber (13.1) and provide the second stage of buffer; When the main shaft transmission (4) of the circuit breaker rotates to the preset end position, the limiting unit is triggered to contact with the main shaft transmission (4) to terminate the circuit breaker opening movement.

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