Vacuum circuit breaker and mechanical characteristic testing method thereof

Abstract

The invention relates to the field of high-voltage switches, in particular to a vacuum circuit breaker and a mechanical characteristic testing method thereof. The device comprises a vacuum arc-extinguishing chamber moving contact, an electric connector, a moving support, a guide cylinder, an insulating pull rod and a contact spring assembly. The upper part of the movable support is provided with a vertically distributed guide channel; the guide cylinder is arranged at the bottom end of the movable support; a moving contact of the vacuum arc-extinguishing chamber upwards penetrates out of the top end of the guide channel; the electric connector is arranged on the periphery of the bottom end of the vacuum arc-extinguishing chamber moving contact; the contact spring assembly comprises a connecting rod arranged at the bottom end of a moving contact of the vacuum arc-extinguishing chamber, a trigger assembly slidably arranged on the guide cylinder and a contact spring connected between the trigger assembly and the connecting rod, and the upper portion of the trigger assembly is unlocked from the connecting rod when extending upwards into the guide channel. The upper portion of the trigger assembly is interlocked with the connecting rod when moving out of the guide channel downwards. According to the invention, the influence on the service life of key parts of the vacuum circuit breaker due to opening overshoot can be avoided. The mechanical characteristic test method can truly reflect the motion state of the moving contact of the vacuum arc-extinguishing chamber.

Description

Technical Field

[0001] This invention relates to the field of high-voltage switches, and in particular to a vacuum circuit breaker and a method for testing its mechanical characteristics. Background Technology

[0002] Vacuum circuit breakers are widely used in power distribution networks due to their advantages of small size, light weight, suitability for frequent operation, and maintenance-free arc extinguishing. However, SF6 circuit breakers dominate the market for circuit breakers at voltage levels of 126kV and above. With the increase in voltage levels, the quality of the moving contacts in vacuum interrupters has significantly improved due to requirements for insulation, temperature rise, and breaking performance.

[0003] Increasing the mass of the moving contact in a vacuum interrupter will lead to inconsistencies between its movement and the operating mechanism during circuit breaker tripping. The reasons are as follows: Vacuum circuit breakers have contact springs between the moving contact and the operating mechanism. To meet the breaking requirements during tripping, the vacuum circuit breaker must reach a certain speed before decelerating and stopping. When the mechanism decelerates or stops during tripping, the moving contact, under the influence of kinetic energy, will overcome the spring force and continue to compress the spring, resulting in abnormal overshoot, collision, and rebound. This affects the breaking performance of the vacuum circuit breaker and the service life of critical components. Furthermore, conventional methods for testing the mechanical characteristics of vacuum circuit breakers involve installing sensors at the mechanism's transmission box. Due to the aforementioned reasons, the inconsistency between the moving contact and the operating mechanism means that the existing sensor results cannot accurately reflect the motion state of the moving contact. Summary of the Invention

[0004] The purpose of this invention is to address the problems existing in the background technology by proposing a vacuum circuit breaker and its mechanical characteristic testing method, which can avoid the impact on the lifespan of key components of the vacuum circuit breaker due to tripping overshoot. The mechanical characteristic testing method can accurately reflect the movement state of the moving contact of the vacuum interrupter.

[0005] On one hand, the present invention proposes a vacuum circuit breaker, including a vacuum interrupter moving contact, an electrical connection, a moving support, a guide cylinder, an insulating pull rod, and a contact spring assembly; the moving support has vertically distributed guide channels on its upper part; the guide cylinder is disposed at the bottom end of the moving support; the vacuum interrupter moving contact extends upward through the top of the guide channel; the electrical connection is disposed on the outer periphery of the bottom end of the vacuum interrupter moving contact and is slidably disposed inside the guide channel; the contact spring assembly includes a connecting rod disposed at the bottom end of the vacuum interrupter moving contact, a trigger assembly slidably disposed on the guide cylinder, and a contact spring connected between the trigger assembly and the connecting rod; when the upper part of the trigger assembly extends upward into the guide channel, it is disengaged from the connecting rod; when the upper part of the trigger assembly moves downward out of the guide channel, it is interlocked with the connecting rod; the insulating pull rod is disposed at the bottom end of the trigger assembly.

[0006] Preferably, the triggering component includes an end cap for vertical sliding of the connecting rod, a spring cylinder disposed at the bottom of the end cap, and a linkage component for interlocking or unlocking the end cap and the connecting rod.

[0007] Preferably, the linkage assembly is arranged in two sets symmetrically about the connecting rod along the radial direction, including spring one, sliding pin one, spring two and sliding pin two. The connecting rod has a groove distributed radially outward, and the end cover has a slide rail that runs radially through. The groove is for sliding pin one to slide, and the slide rail is for sliding pin one and sliding pin two to slide. Sliding pin two is located on the outer periphery of sliding pin one. Spring one is connected between sliding pin one and the bottom of the groove, and spring two is connected between sliding pin two and the end cover.

[0008] Preferably, the top and bottom of the outer side of the sliding pin one are chamfered, the outer end of the sliding pin two is a hemispherical structure, and the moving support is flared at the bottom of the guide channel.

[0009] Preferably, the linkage assembly further includes a limiting plate disposed at the outer end of the slide rail. The limiting ring has a through hole through which the outer end of the second sliding shaft pin passes. The outer periphery of the second sliding shaft pin has an outwardly protruding convex ring portion. The limiting plate limits the outward movement limit position of the second sliding shaft pin through the convex ring portion.

[0010] Preferably, the slide of the end cap includes a slide section one, a connecting section and a slide section two connected sequentially from the outside to the inside. The cross-sectional dimension of the connecting section is smaller than the cross-sectional dimensions of the slide section one and the slide section two. The protruding ring of the sliding pin two is slidably disposed inside the slide section one, and one end of the inner side of the sliding pin two passes through the connecting section and extends into the slide section two.

[0011] Preferably, when the sliding pin 2 extends upward into the guide channel, the passive support pushes inward and pushes the sliding pin 1 from between the slide section 2 and the slide groove into the slide groove, releasing the interlock between the end cover and the connecting rod. When the sliding pin 2 moves downward out of the guide channel, it is pushed outward by the spring 2. The spring 1 pushes the sliding pin 1 outward until it is stuck between the slide section 2 and the slide groove, interlocking the end cover and the connecting rod.

[0012] On the other hand, the present invention proposes a method for testing the mechanical characteristics of the above-mentioned vacuum circuit breaker, comprising the following steps: S1. A linear displacement sensor is placed between the end cap and the electrical connection; S2. Set the sampling frequency of the linear displacement sensor to the same sampling frequency as the sensor at the transmission box of the mechanism; S3. Based on the difference between the sampled data sets of the two sensors, accurately reflect the motion state of the moving contact of the vacuum interrupter.

[0013] Compared with the prior art, the present invention has the following beneficial technical effects: the vacuum circuit breaker of the present invention can maintain the consistency of the movement between the moving contact of the vacuum interrupter and the operating mechanism during opening, avoiding the impact on the life of key components of the vacuum circuit breaker due to opening overshoot. The mechanical characteristic testing method can also accurately reflect the movement state of the moving contact of the vacuum interrupter. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the open state of the vacuum circuit breaker of the present invention; Figure 2 This is a partially enlarged view of the transmission structure of the vacuum circuit breaker in the open state of the present invention; Figure 3 This is a partially enlarged view of the transmission structure of the vacuum circuit breaker of the present invention when the closing stroke reaches 80mm (the opening stroke reaches 40mm); Figure 4 This is a partially enlarged view of the transmission structure of the vacuum circuit breaker of the present invention when the closing stroke reaches 100mm (the opening stroke reaches 20mm); Figure 5 This is a partially enlarged view of the transmission structure of the vacuum circuit breaker in the closed state of the present invention; Figure 6 for Figure 5 Enlarged view of the structure at point A in the middle.

[0015] Reference numerals in the attached drawings: 1. Moving contact of vacuum interrupter; 2. Electrical connection; 3. Moving support; 4. Contact spring assembly; 401. Connecting rod; 402. End cap; 403. Spring cylinder; 404. Contact spring; 405. Spring one; 406. Sliding pin one; 407. Spring two; 408. Sliding pin two; 409. Limiting plate; 5. Guide cylinder; 6. Insulating pull rod; 7. Linear displacement sensor. Detailed Implementation

[0016] Example 1: As Figures 1-6 As shown in this embodiment, a vacuum circuit breaker includes a vacuum interrupter moving contact 1, an electrical connection 2, a moving support 3, a guide cylinder 5, an insulating pull rod 6, and a contact spring assembly 4. The total stroke of the vacuum circuit breaker is 120 mm, the stroke of the vacuum interrupter moving contact 1 is 100 mm, and the compression stroke of the contact spring 404 is 20 mm.

[0017] like Figure 1 As shown, the movable support 3 has vertically distributed guide channels on its upper part. A guide cylinder 5 is located at the bottom of the movable support 3 and is connected by bolts. An insulating pull rod 6 is located at the bottom of the trigger assembly. The moving contact 1 of the vacuum interrupter extends upwards through the top of the guide channel of the movable support 3. The electrical connection 2 is located on the outer periphery of the bottom of the moving contact 1 of the vacuum interrupter and is slidably positioned inside the guide channel, which guides the electrical connection 2.

[0018] The contact spring assembly 4 includes a connecting rod 401 disposed at the bottom end of the moving contact 1 of the vacuum interrupter, a trigger assembly slidably disposed on the guide cylinder 5, and a contact spring 404 connected between the trigger assembly and the connecting rod 401. Specifically, the contact spring 404 is tensioned between the bottom end of the connecting rod 401 and the inner bottom end of the spring cylinder 403. When the upper part of the trigger assembly extends upward into the guide channel, it disengages from the connecting rod 401; when the upper part of the trigger assembly moves downward out of the guide channel, it interlocks with the connecting rod 401. When the trigger assembly and the connecting rod 401 are interlocked, they can move synchronously.

[0019] The triggering assembly includes an end cap 402 for vertical sliding of the connecting rod 401, a spring cylinder 403 disposed at the bottom of the end cap 402, and a linkage assembly for locking or unlocking the end cap 402 and the connecting rod 401. Specifically, the end cap 402 is used to lock or unlock the connecting rod 401. The triggering assembly slides on the inner circumferential surface of the guide cylinder 5 via the spring cylinder 403.

[0020] Two sets of linkage components are symmetrically arranged radially around the connecting rod 401. Alternatively, three or four sets can be evenly arranged around the central axis of the connecting rod 401. The linkage components include a first spring 405, a first sliding pin 406, a second spring 407, a second sliding pin 408, and a limiting plate 409. The connecting rod 401 has radially outwardly distributed grooves, and the end cap 402 has a radially through-type slide rail. The grooves allow the first sliding pin 406 to slide, and the slide rail allows both the first and second sliding pins 406 to slide. The second sliding pin 408 is located on the outer periphery of the first sliding pin 406, meaning the distance from the second sliding pin 408 to the central axis of the connecting rod 401 is greater than the distance from the first sliding pin 406 to the central axis of the connecting rod 401. Spring 1 405 is connected between sliding pin 1 406 and the bottom of the slide groove, and spring 2 407 is connected between sliding pin 2 408 and end cap 402. Both spring 1 405 and spring 2 407 have sufficient extension and retraction space.

[0021] To ensure smooth sliding of sliding pin 406 into the slideway of end cover 402, both the top and bottom edges of sliding pin 406 are chamfered. To ensure smooth inward pushing of sliding pin 408 by the bottom of the guide channel, the outer end of sliding pin 408 has a hemispherical structure, and the movable support 3 is flared at the bottom of the guide channel. As sliding pin 408 moves from bottom to top, it is pushed inward by the flared portion at the bottom of the guide channel, and the hemispherical structure also reduces wear from sliding contact with the movable support 3.

[0022] like Figure 6 As shown, the limiting plate 409 is disposed at the outer end of the slide rail. The limiting plate 409 has a through hole through which the outer end of the sliding shaft pin 408 passes. The outer periphery of the sliding shaft pin 408 has an outwardly protruding ring portion. The limiting plate 409 limits the outward movement limit position of the sliding shaft pin 408 through the protruding ring portion.

[0023] like Figure 6 As shown, the slide of end cap 402 includes slide section one, connecting section and slide section two connected sequentially from the outside to the inside. The cross-sectional dimension of the connecting section is smaller than the cross-sectional dimensions of slide section one and slide section two. Spring two 407 is specifically connected between the convex ring section and the connecting section, and spring two 407 extends and retracts within this range. The cross-sectional dimension of slide section two is the same as the cross-sectional dimension of the slide groove, both of which allow sliding pin one 406 to slide. When the two ends of sliding pin one 406 are located inside slide section two and inside slide groove respectively, it indicates that sliding pin one 406 is locked between slide section and slide groove, interlocking end cap 402 and connecting rod 401. The convex ring section of sliding pin two 408 is slidably disposed inside slide section one, and one end of sliding pin two 408 passes through the connecting section and extends into slide section two.

[0024] The closing process of a vacuum circuit breaker is as follows Figures 1-5 The sequence proceeds as follows: when the vacuum circuit breaker's closing stroke reaches 80mm, sliding pin 2 408 begins to enter the guide channel. As sliding pin 2 408 extends upward into the guide channel, passive support 3 pushes inward, compressing spring 2 407 and pushing sliding pin 1 406 from between slide section 2 and slide groove until it is completely inside the slide groove. At this time, the vacuum circuit breaker's closing stroke reaches 100mm, and sliding pin 1 406 compresses spring 1 405. This releases the interlock between end cover 402 and connecting rod 401. At this time, the moving contact 1 of the vacuum interrupter moves into position, and insulating pull rod 6 continues to push spring cylinder 403 upward, compressing contact spring 404.

[0025] Conversely, the opening process of a vacuum circuit breaker follows the same principle. Figures 5-1 The sequence is as follows: when the sliding pin 408 moves downward out of the guide channel, it is pushed outward by the spring 407. The spring 405 pushes the sliding pin 406 outward in the opposite direction until it is re-locked between the slide section 2 and the slide groove. At this point, the end cover 402 and the connecting rod 401 are re-locked. When the insulating pull rod 6 continues to move downward, the moving contact 1 of the vacuum interrupter can maintain synchronous movement.

[0026] This embodiment eliminates the phenomenon that when the vacuum circuit breaker is opened, the moving contact 1 of the vacuum interrupter is compressed by the contact spring 404 under the action of kinetic energy due to the deceleration or stopping of the mechanism. It can maintain the consistency of the action between the moving contact 1 of the vacuum interrupter and the operating mechanism, and solve the problem of the impact of opening overshoot on the life of key components of the vacuum circuit breaker.

[0027] Example 2: Figures 1-6 As shown, this embodiment proposes a mechanical characteristic testing method for testing the mechanical characteristics of the vacuum circuit breaker in Embodiment 1. The testing method includes the following steps: S1. A linear displacement sensor 7 is arranged between the end cap 402 and the electrical connection 2; S2. Set the sampling frequency of the linear displacement sensor 7 to the same sampling frequency as the sensor at the transmission box of the mechanism; S3. Based on the difference between the sampled data sets of the two sensors, accurately reflect the motion state of the moving contact 1 of the vacuum interrupter.

[0028] The test method in this embodiment can truly reflect the motion state of the moving contact 1 of the vacuum interrupter.

[0029] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited thereto. Various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention.

Claims

1. A vacuum circuit breaker, characterized in that, include: The movable support (3) has vertically distributed guide channels on the upper part and a guide cylinder (5) at the bottom. The moving contact (1) of the vacuum interrupter extends upward through the top of the guide channel; The electrical connection (2) is located on the outer periphery of the bottom end of the moving contact (1) of the vacuum interrupter and is slidably located inside the guide channel; The contact spring assembly (4) includes a connecting rod (401) disposed at the bottom end of the moving contact (1) of the vacuum interrupter, a trigger assembly slidably disposed on the guide cylinder (5), and a contact spring (404) connected between the trigger assembly and the connecting rod (401). When the upper part of the trigger assembly extends upward into the guide channel, it is disengaged from the connecting rod (401), and when the upper part of the trigger assembly moves downward out of the guide channel, it is interlocked with the connecting rod (401). An insulating pull rod (6) is set at the bottom of the trigger assembly.

2. The vacuum circuit breaker according to claim 1, characterized in that, The triggering assembly includes an end cap (402) for vertical sliding of the connecting rod (401), a spring cylinder (403) disposed at the bottom of the end cap (402), and a linkage assembly for interlocking or de-interlocking the end cap (402) and the connecting rod (401).

3. The vacuum circuit breaker according to claim 2, characterized in that, Two sets of linkage components are arranged radially symmetrically about the connecting rod (401), including spring one (405), sliding pin one (406), spring two (407) and sliding pin two (408). The connecting rod (401) has a groove distributed radially outward, and the end cover (402) has a slide rail that runs radially through. The groove is for sliding pin one (406) to slide, and the slide rail is for sliding pin one (406) and sliding pin two (408) to slide. Sliding pin two (408) is located on the outer periphery of sliding pin one (406). Spring one (405) is connected between sliding pin one (406) and the bottom of the groove, and spring two (407) is connected between sliding pin two (408) and end cover (402).

4. The vacuum circuit breaker according to claim 3, characterized in that, The top and bottom of the outer side of sliding pin one (406) are chamfered, the outer end of sliding pin two (408) is a hemispherical structure, and the moving support (3) is flared at the bottom of the guide channel.

5. The vacuum circuit breaker according to claim 3, characterized in that, The linkage assembly also includes a limiting plate (409) disposed at the outer end of the slide. The limiting ring (9) has a through hole through which the outer end of the sliding pin (408) passes. The outer periphery of the sliding pin (408) has an outwardly protruding ring portion. The limiting plate (409) limits the outward movement limit position of the sliding pin (408) through the protruding ring portion.

6. The vacuum circuit breaker according to claim 5, characterized in that, The slide of the end cap (402) includes a slide section 1, a connecting section and a slide section 2 connected sequentially from the outside to the inside. The cross-sectional dimension of the connecting section is smaller than the cross-sectional dimensions of the slide section 1 and the slide section 2. The protruding ring of the sliding pin 2 (408) is slidably disposed inside the slide section 1. One end of the inner side of the sliding pin 2 (408) passes through the connecting section and extends into the slide section 2.

7. The vacuum circuit breaker according to claim 6, characterized in that, When the sliding pin 2 (408) extends upward into the guide channel, the passive support (3) pushes inward and pushes the sliding pin 1 (406) from between the slide section 2 and the slide groove into the slide groove, releasing the interlock between the end cover (402) and the connecting rod (401). When the sliding pin 2 (408) moves downward out of the guide channel, it is pushed outward by the spring 2 (407). The spring 1 (405) pushes the sliding pin 1 (406) outward until it is stuck between the slide section 2 and the slide groove, interlocking the end cover (402) and the connecting rod (401).

8. A method for testing the mechanical characteristics of a vacuum circuit breaker according to claim 2, characterized in that, Includes the following steps: S1. A linear displacement sensor (7) is arranged between the end cap (402) and the electrical connection (2); S2. Set the sampling frequency of the linear displacement sensor (7) to the same sampling frequency as the sensor at the transmission box of the mechanism; S3. Based on the difference between the two sensor sampling datasets, accurately reflect the motion state of the moving contact (1) of the vacuum interrupter.

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