CN112259409A

CN112259409A - Vacuum arc extinguish chamber, vacuum circuit breaker and switching-on and switching-off control method of vacuum circuit breaker

Info

Publication number: CN112259409A
Application number: CN202010981544.6A
Authority: CN
Inventors: 齐大翠; 李小钊; 刘畅; 柴娜; 张杨; 王宇浩; 李锟; 刘世柏; 赵芳帅; 薛从军; 亓春伟
Original assignee: State Grid Corp of China SGCC; State Grid Zhejiang Electric Power Co Ltd; Pinggao Group Co Ltd
Current assignee: State Grid Corp of China SGCC; State Grid Zhejiang Electric Power Co Ltd; Pinggao Group Co Ltd
Priority date: 2020-09-17
Filing date: 2020-09-17
Publication date: 2021-01-22

Abstract

The invention relates to a vacuum arc extinguish chamber, a vacuum circuit breaker and a switching-on and switching-off control method of the vacuum circuit breaker. And the movable contact rod and the movable arc contact can move back and forth relative to the movable main contact and the vacuum arc extinguish chamber shell, the movable main contact can move back and forth relative to the shell, the movable contact rod and the movable arc contact are driven by the arc contact driving mechanism to independently move back and forth during switching-on and switching-off operation, and the movable main contact is driven by the main contact driving mechanism to independently move back and forth, so that double-acting control is realized, the switching-on and switching-off sequence requirements of the main contact and the arc contact in the switching-on and switching-off operation process are effectively met, the static contact component is not required to be capable of moving back and forth, and the requirement on the motion installation space of.

Description

Vacuum arc extinguish chamber, vacuum circuit breaker and switching-on and switching-off control method of vacuum circuit breaker

Technical Field

The invention relates to a vacuum arc-extinguishing chamber, a vacuum circuit breaker and a switching-on and switching-off control method of the vacuum circuit breaker.

Background

High voltage circuit breakers are the most important control and protection devices in electrical power systems. At present, almost all circuit breakers of 72.5kV and above used in electric power systems are SF₆Circuit breakers, however SF₆The gas is the strongest greenhouse effect gas limited by international convention, and environment-friendly switchgear is developed to replace SF₆The circuit breaker has become a research hotspot in the field of high-voltage switches at home and abroad.

Vacuum circuit breakers are now widely used in medium voltage distribution systems, but for high voltage vacuum circuit breakers there are few applications in power systems. At present at 72.5kIn the transmission class of V, the vacuum interrupter accounts for only 0.56%. Obviously, with SF₆Using a vacuum circuit breaker of high voltage class (transmission class) instead of SF₆Circuit breakers have become a necessary trend.

Generally, a single-electrode contact structure is adopted for the vacuum arc-extinguishing chamber, current flows through the contact structure to generate a magnetic field, and the magnetic field acts on electric arcs to diffuse the electric arcs, so that the aim of successfully switching off the current is fulfilled. For a vacuum arc-extinguishing chamber with a high voltage level, a large enough distance is needed to bear high voltage, but the magnetic field is reduced along with the increase of the distance, and a longitudinal magnetic field contact structure is a necessary structure to ensure that the magnetic field is sufficient under the large distance. Among the longitudinal magnetic field contact structures, the coil type contact structure is the most commonly used contact structure at present due to the uniform magnetic field and the high short-circuit current breaking capability. However, the limitation of this structure is that the contact structure has a long current path and a large resistance, and the current capacity of the rated current cannot be made very large, and currently only 2500A can be achieved. The U-shaped two-pole longitudinal magnetic field contact structure has strong longitudinal magnetic field, but the uniformity of the magnetic field is poor, and the contact area is only half of the contact area due to the two directions of the longitudinal magnetic field, so that the breaking capacity of short-circuit current is limited. Therefore, in the vacuum arc-extinguishing chamber with high voltage class, the capability of short-circuit breaking current and the current capability of rated current are a pair of typical contradictions, and the rated current of the contact structure with large breaking capability is not large, so that the application of the vacuum arc-extinguishing chamber in the high voltage field is limited.

The invention discloses a high-capacity vacuum load switch, wherein a moving main contact, a static main contact, a moving arc contact and a static arc contact which are used in a matched mode are arranged in a ceramic shell, the moving arc contact protrudes out of the moving main contact, the moving main contact and the moving arc contact move together under the driving of a moving conducting rod during switching, the moving arc contact is in conductive contact with the static arc contact at first, at the moment, the moving main contact is not in contact with the static main contact, the moving conducting rod continues to move, the static arc contact drives the conducting rod at the static end to retreat, and an energy storage spring at the tail end is compressed to store energy until the moving main contact is in contact with the static main contact, at the moment, most of current is transferred to the moving main contact and the static main contact from the moving arc contact and the static arc contact, namely, the moving main contact and the static main contact complete a large-current bearing task. When the brake needs to be switched off, the movable conducting rod moves reversely, the movable main contact and the static main contact are firstly separated, the movable arc contact and the static arc contact are still in a conducting state, the movable conducting rod continues to move until the movable arc contact and the static arc contact are separated, electric arcs can be burnt on the movable arc contact and the static arc contact in the whole range of the opening distance, and the electric arcs are easily extinguished because the movable arc contact and the static arc contact adopt a longitudinal magnetic structure. That is, by configuring the movable and static arc contacts and the movable and static main contacts, the vacuum arc-extinguishing chamber can simultaneously have the capacity of carrying large rated current and breaking large short-circuit current.

The vacuum arc-extinguishing chamber disclosed in the chinese invention patent application with application publication No. CN111463061A also has a structure of moving and static arc contacts and moving and static main contacts, so that the arc-extinguishing chamber has the capability of carrying a large rated current and breaking a large short-circuit current at the same time, wherein the moving and static arc contacts specifically adopt a coil magnetic field contact structure.

In fact, in the vacuum interrupter disclosed in the above two patent documents, not only the moving contact rod needs to move during the opening and closing operation, but also the static arcing contact needs to be moved backward when being pressed by the moving arcing contact, and accordingly, the corresponding contact rod supporting and mounting the static arcing contact needs to be moved backward, and an elastic member is usually provided to drive the static arcing contact and the corresponding contact rod to move forward and return. Therefore, when the vacuum arc-extinguishing chamber is applied, not only the movement space of the guide rod for driving the movable main contact to move needs to be reserved, but also the movement space of the conducting rod corresponding to the static arc contact needs to be reserved, and if no redundant space exists on one side of the static end of the arc-extinguishing chamber in a corresponding application field, the vacuum arc-extinguishing chamber is not suitable for being applied.

Disclosure of Invention

The invention aims to provide a vacuum arc-extinguishing chamber, which aims to solve the technical problem that in the prior art, a static arc contact and a corresponding conducting rod in the vacuum arc-extinguishing chamber which is simultaneously provided with a static arc contact and a dynamic arc contact and a static main contact reciprocate and a corresponding motion space needs to be reserved in an arc-extinguishing chamber application place; meanwhile, the invention also provides a vacuum circuit breaker using the vacuum arc extinguish chamber and a switching-on and switching-off control method of the vacuum circuit breaker.

In order to achieve the purpose, the technical scheme of the vacuum arc-extinguishing chamber provided by the invention is as follows: vacuum interrupter, includes:

a housing extending in a front-rear direction;

the static contact assembly is positioned in the shell and comprises a static main contact and a static arc contact which are in conductive connection;

the movable contact assembly is positioned in the shell and comprises a movable main contact and a movable arc contact, the movable main contact is used for conducting contact with the static main contact so as to normally pass through the movable contact, the movable arc contact is used for breaking and arc extinguishing with the static arc contact, and the movable main contact and the movable arc contact move forwards so as to correspondingly conduct contact with the static main contact and the static arc contact;

the movable main contact is sleeve-shaped and sleeved outside the movable arc contact at intervals, and the movable main contact can reciprocate relative to the shell in the front-back direction;

the outer sealing corrugated pipe is connected between the shell and the movable main contact in a sealing manner;

the moving contact rod is sleeved in the moving main contact in a penetrating way and can relatively slide along the front-back direction, and is in conductive connection with the moving main contact, and the moving arc contact is fixedly arranged at the front end of the moving contact rod;

the inner sealing corrugated pipe is connected between the movable contact rod and the movable main contact in a sealing manner;

the rear part of the movable main contact is provided with a main contact driving part which is used for being in transmission connection with a corresponding main contact driving mechanism and driving the movable main contact to move back and forth relative to the shell;

the rear part of the movable contact rod is provided with an arc contact driving part which is used for being in transmission connection with a corresponding arc contact driving mechanism to drive the movable contact rod and the movable arc contact to move back and forth relative to the movable main contact and the shell;

when the vacuum arc extinguish chamber is switched on, the movable arc contact is in conductive contact with the static arc contact, and then the movable main contact is in conductive contact with the static main contact to realize normal through-flow; when the vacuum arc-extinguishing chamber is opened, the movable main contact and the static main contact are opened, and then the movable arc contact and the static arc contact are opened to extinguish arc.

The beneficial effects are that: the vacuum arc extinguish chamber is provided with the movable main contact and the static main contact for realizing normal through-flow, and the movable arc contact and the static arc contact for realizing cut-off arc extinguishing, so that the whole vacuum arc extinguish chamber has both large through-flow capacity and high cut-off performance, and the application place of the vacuum arc extinguish chamber is enlarged. And the movable main contact and the movable contact rod can respectively and independently move back and forth relative to the shell, the main contact driving mechanism of the vacuum circuit breaker can drive the movable main contact to reciprocate, the arc contact driving mechanism of the vacuum circuit breaker drives the movable contact rod to reciprocate, and double-acting control is realized, so that the switching sequence requirements of the main contact and the arc contact in the switching-on and switching-off operation process are effectively met, further, the static contact component is not required to be capable of reciprocating, the requirement of the installation space corresponding to the movement of the static contact component is reduced, and the movable contact component can be applied to places where the installation space is insufficient and the requirement of the movable space of the static contact component cannot be met.

As a further improvement, a packing support part is fixedly arranged on the inner side of the movable main contact, a through hole is formed in the center of the packing support part, and a movable contact rod is arranged in the through hole in a guiding and penetrating mode along the front-back direction.

The beneficial effects are that: the movable contact rod is guided and supported by the packing supporting part to be assembled inside the movable main contact, the movable contact components can be assembled together in advance to form a pre-assembly body, and then the pre-assembly body is assembled in the shell in a front-back movable mode, so that the movable contact rod is convenient to install.

As a further improvement, one end of the inner sealing corrugated pipe is fixedly connected to the sealing support part so as to be indirectly sealed and connected between the movable contact rod and the movable main contact.

The beneficial effects are that: one end of the inner plugging corrugated pipe is connected to the plugging supporting part, so that the installation is convenient.

As a further improvement, an inner shielding cover is fixedly sleeved on the movable contact rod at the rear side of the movable arc contact, the inner shielding cover is provided with a rear cylinder shielding section which is folded and extended backwards, and the rear cylinder shielding section at least covers the front part of the inner plugging corrugated pipe from front to back.

The beneficial effects are that: the rear cylinder body shielding section of the inner shielding cover shields the inner plugging corrugated pipe, so that the influence of the front tip of the inner plugging corrugated pipe on an electric field can be effectively prevented.

As a further improvement, the inner shield is fixedly connected to the front end of the inner plugging corrugated pipe, and the inner shield is in sealing fit with the movable contact rod so as to realize the sealing assembly of the inner shield and the movable contact rod; the movable contact rod is provided with a stop step, the step surface of the stop step is arranged backwards, and the stop step is in stop fit with the inner shield cover so as to be matched with the inner plugging corrugated pipe to fix the inner shield cover on the movable contact rod.

The beneficial effects are that: the inner shield cover is fixed at the front end of the inner plugging corrugated pipe and is blocked by the blocking step, so that the assembly is convenient.

As a further improvement, the movable contact rod comprises a contact rod main body, a movable terminal and a transmission connecting rod are arranged at the rear part of the contact rod main body, the movable arc contact is fixed at the front end of the contact rod main body, the movable main contact is provided with a sliding conductive cylinder, the movable terminal is assembled in the sliding conductive cylinder in a sliding manner along the front-back direction, a spring contact finger is arranged in the sliding conductive cylinder to realize the conductive connection of the movable main contact and the movable contact rod, the transmission connecting rod is fixedly connected with the movable terminal or the contact rod main body, and the transmission connecting rod is used as the arc contact driving part and is used for being in transmission connection with an arc contact driving mechanism.

As a further improvement, the vacuum arc-extinguishing chamber comprises a stationary contact rod extending in the front-rear direction, the stationary arc contact is located at the rear end of the stationary contact rod, the stationary main contact is fixedly sleeved outside the stationary contact rod, the stationary main contact is provided with a stationary contact sleeve section, the stationary contact sleeve section is sleeved outside the stationary arc contact at intervals, the rear end of the stationary contact sleeve section is used for being in conductive contact with the moving main contact, the stationary main contact is provided with a set length, so that a set distance is formed between the rear end of the stationary contact sleeve section and the front end of the stationary arc contact, and the moving arc contact is guaranteed to be matched with the stationary arc contact to realize breaking and breaking before exiting the stationary contact sleeve section backwards, so that the stationary contact sleeve section absorbs arc generated after arc.

The beneficial effects are that: the static main contact is provided with a static contact sleeve section, the static main contact is provided with a set length, so that a set distance is formed between the rear end of the static contact sleeve section and the front end of the static arc contact, and the movable arc contact is still positioned in the static main contact when the two arc contacts are switched off and arc extinguishing is guaranteed.

The technical scheme of the vacuum circuit breaker provided by the invention is as follows:

the vacuum circuit breaker comprises a vacuum arc extinguish chamber, a main contact driving mechanism and an arc contact driving mechanism,

vacuum interrupter, includes:

a housing extending in a front-rear direction;

the rear part of the movable main contact is provided with a main contact driving part which is in transmission connection with the main contact driving mechanism and drives the movable main contact to move back and forth relative to the shell;

the rear part of the movable contact rod is provided with an arc contact driving part which is in transmission connection with the arc contact driving mechanism and drives the movable contact rod and the movable arc contact to move back and forth relative to the movable main contact and the shell;

The beneficial effects are that: in the vacuum circuit breaker provided by the invention, the vacuum arc extinguish chamber is internally provided with the movable main contact and the static main contact for realizing normal through-flow, and the movable arc contact and the static arc contact for realizing cut-off arc extinguishing, so that the whole vacuum arc extinguish chamber has both high through-flow capacity and high cut-off performance, and the application place of the vacuum arc extinguish chamber is expanded. And the movable main contact and the movable contact rod can respectively and independently move back and forth relative to the shell, the main contact driving mechanism of the vacuum circuit breaker can drive the movable main contact to reciprocate, the arc contact driving mechanism of the vacuum circuit breaker drives the movable contact rod to reciprocate, and double-acting control is realized, so that the switching sequence requirements of the main contact and the arc contact in the switching-on and switching-off operation process are effectively met, further, the static contact component is not required to be capable of reciprocating, the requirement of the installation space corresponding to the movement of the static contact component is reduced, and the movable contact component can be applied to places where the installation space is insufficient and the requirement of the movable space of the static contact component cannot be met.

The technical scheme of the switching-on and switching-off control method of the vacuum circuit breaker provided by the invention is as follows:

the switch-on and switch-off control method of the vacuum circuit breaker, in the vacuum arc-extinguishing chamber, the moving contact stick and moving arc contact can move the main contact, outer casing of the vacuum arc-extinguishing chamber back and forth relatively, the moving main contact can move the main contact back and forth relatively to outer casing of the vacuum arc-extinguishing chamber;

when the switch-on operation is carried out, the arc contact driving mechanism drives the movable contact rod and the movable arc contact to independently move forwards to be in conductive contact with the static arc contact in the vacuum arc extinguishing chamber, the main contact operating structure drives the movable main contact to independently move forwards to be in conductive contact with the static main contact in the vacuum arc extinguishing chamber, and after the movable arc contact is in conductive contact with the static arc contact, the movable main contact is in conductive contact with the static main contact again to realize normal through-flow;

when the switching-off operation is carried out, the arc contact driving mechanism drives the movable contact rod and the movable arc contact to independently move backwards to be disconnected with the static arc contact in the vacuum arc extinguishing chamber, the main contact operating structure drives the movable main contact to independently move backwards to be disconnected with the static main contact in the vacuum arc extinguishing chamber, and after the movable main contact is disconnected with the static main contact, the movable arc contact is disconnected with the static arc contact to extinguish arc.

The beneficial effects are that: according to the switching-on and switching-off control method provided by the invention, the main contact driving mechanism can be used for independently driving the main contact to reciprocate, the arc contact driving structure can be used for independently driving the movable contact rod and the movable arc contact to reciprocate, and then double-acting control is realized, so that the switching-on and switching-off sequence requirements of the main contact and the arc contact in the switching-on and switching-off operation process are effectively met, and the normal switching-on and switching-off work of the vacuum circuit breaker is met.

As a further improvement, when the switching-on operation is carried out, the movable contact rod and the movable arc contact move forwards synchronously with the movable main contact first until the movable arc contact is in conductive contact with the static arc contact, and then the movable main contact moves forwards independently until the movable main contact is in conductive contact with the static main contact, so that normal through-flow is realized; when the switching-off operation is carried out, the movable main contact independently moves backwards for a set distance to be disconnected with the static main contact, and then the movable main contact, the movable contact rod and the movable arc contact synchronously move backwards again, so that the movable arc contact and the static arc contact are disconnected and arc-extinguishing.

The beneficial effects are that: in the switching-on and switching-off operation process, a section of stroke for synchronously moving the movable main contact and the movable arc contact is respectively set, so that the whole switching-on and switching-off action stroke is conveniently designed, and the design process is simplified.

Drawings

Fig. 1 is a schematic structural diagram of an embodiment 1 of a vacuum interrupter provided by the present invention;

fig. 2 is a schematic structural view of the vacuum interrupter shown in fig. 1 when the moving arc contact and the stationary arc contact are closed during a closing process;

fig. 3 is a schematic structural view of the movable main contact and the static main contact closed when the vacuum interrupter shown in fig. 1 completes the closing;

fig. 4 is a schematic structural diagram of the vacuum interrupter shown in fig. 1 when the movable main contact and the static main contact are opened during the opening process;

fig. 5 is a schematic structural diagram of the vacuum interrupter shown in fig. 1 when the moving arc contact and the fixed arc contact are opened during the opening process.

Description of reference numerals:

1-static cover plate; 2-a housing; 3-static contact bar; 4-static arc contact (coil structure inside); 5-moving arc contact (coil structure inside); 6-inner shield cover; 7-moving contact bar; 8-inner plugging bellows; 9-fixing a flange; 10-a guide sleeve; 11-a movable terminal; 12-connecting screw; 13-spring contact fingers; 14-moving the cover plate; 15-external plugging of the corrugated pipe; 16-a support ring; 17-a bellows retaining ring; 18-moving main contacts; 19-moving contact ring; 20-stationary contact ring; 21-middle seal ring; 22-stationary main contacts; 181-cover plate portion; 100-a main contact drive mechanism; 200-arc contact drive mechanism.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that relational terms such as "first" and "second," and the like, may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, elements recited by the phrase "comprising an … …" do not exclude the inclusion of such elements in processes or methods.

In the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" when they are used are to be construed broadly, e.g., as meaning a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; either directly or indirectly through intervening media, or may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those skilled in the art from specific situations.

In the description of the present invention, it should be noted that, unless explicitly stated or limited otherwise, the term "provided" may be used in a broad sense, for example, the object of "provided" may be a part of the body, or may be arranged separately from the body and connected to the body, and the connection may be a detachable connection or a non-detachable connection. The specific meaning of the above terms in the present invention can be understood by those skilled in the art from specific situations.

The present invention will be described in further detail with reference to examples.

The specific embodiment 1 of the vacuum arc-extinguishing chamber provided by the invention is as follows:

as shown in fig. 1, the vacuum interrupter in this embodiment includes a housing 2, which is a metalized porcelain shell, and a center seal ring 21 is disposed in the middle of the housing 2. The shell 2 is of a cylindrical structure, the axial direction extends along the front-back direction, the front end is provided with a static cover plate 1, and the rear end is provided with a movable cover plate 14.

Quiet 1 one side of apron is fixed and is provided with

quiet contact stick

3, 3 axial of quiet contact stick extend along the fore-and-aft direction, quiet contact subassembly is installed to its rear side, quiet contact subassembly is located shell 2, specifically include quiet main contact 22 and quiet arc contact 4, the inside coil type structure that is of quiet arc contact 4, be used for breaking the arc extinguishing, 4 fixed mounting in the 3 rear ends of quiet contact stick of quiet arc contact, quiet main contact 22 fixed suit is outside quiet contact stick 3, leave the arc separation clearance between quiet main contact 22 of here and quiet arc contact 4, and, quiet

main contact

22 and 3 fixed connection of quiet contact stick, through

quiet contact stick

3 and 4 conductive connection of quiet arc contact.

The static main contact 22 has a static contact sleeve section extending backwards, the static contact sleeve section is sleeved outside the static arc contact 4 at intervals, and a static contact ring 20 is arranged at the rear end of the static contact sleeve section for electrically contacting with the movable contact ring 19 on the movable main contact 18. In this embodiment, the static contact sleeve segment needs to have a set length, so that the static main contact 22 has a set length, so that the rear end of the static contact sleeve segment has a set distance from the front end of the static arc contact 4, it is ensured that the moving arc contact 5 is matched with the static arc contact 4 to realize the on-off arc extinguishing before exiting the static contact sleeve segment backwards, the static contact sleeve segment can absorb the post-arc product generated when the electric arc is generated, and then the main shield used for absorbing the post-arc product inside the vacuum arc extinguish chamber in the prior art is replaced, thereby effectively ensuring the insulating function of the housing 2. The set length of the static main contact 22 can be set independently according to vacuum arc-extinguishing chambers of different models, and only the arc is drawn before the moving arc contact 5 exits the static contact sleeve section backwards for extinguishing.

The movable contact component is further installed inside the shell 2 and comprises a movable main contact 18 and a movable arc contact 5, the movable main contact 18 is used for being in conductive contact with the static main contact 22 to normally pass through, the movable arc contact 5 is used for being matched with the static arc contact 4 to break and extinguish arc, and the movable main contact 18 and the movable arc contact 5 move forwards to be in conductive contact with the static main contact 22 and the static arc contact 4 correspondingly.

The moving main contact 18 is generally sleeve-shaped and extends axially in the forward and rearward directions, and has a moving contact ring 19 at its forward end for electrically conductive contact with a stationary contact ring 20 on a stationary main contact 22. Because the movable main contact 18 is assembled in the shell 2 in a reciprocating manner along the front-back direction, in order to realize the sealing between the movable main contact 18 and the shell 2 and ensure the air tightness of the vacuum arc-extinguishing chamber, an outer sealing corrugated pipe 15 is connected between the shell 2 and the movable main contact 18 in a sealing manner, the axial direction of the outer sealing corrugated pipe 15 extends along the front-back direction, the rear end of the outer sealing corrugated pipe 15 is fixedly connected on the movable cover plate 14 in a sealing manner, a corrugated pipe fixing ring 17 is fixedly arranged on the outer side of the middle part of the movable main contact 18, and the front end of the outer sealing corrugated pipe 15 is fixedly connected on the corrugated pipe fixing ring 17 in a sealing manner, so that the outer sealing corrugated pipe 15 is indirectly connected between the shell 2 and the movable main contact 18 through the.

The rear end of the movable main contact 18 is provided with a main contact driving part which is used for being in transmission connection with a corresponding main contact driving mechanism 100, so that the movable main contact 18 can move back and forth relative to the movable contact rod 7, the movable arc contact 5 and the shell 2. Actually, the rear end of the movable main contact 18 is a cover portion 181, the cover portion 181 is used as a main contact driving portion, and the output rod of the main contact driving mechanism 100 and the cover portion 181 of the movable main contact 18 may be fixedly connected by a bolt.

The rear end of the sleeve-shaped movable main contact 18 is integrally connected with a sliding conductive cylinder through a cover plate part 181, the sliding conductive cylinder extends along the front-back direction, the movable contact rod 7 can be assembled in the sliding conductive cylinder in a relative movement manner along the front-back direction, and a plurality of spring contact fingers 13 are arranged in the sliding conductive cylinder to realize the conductive connection of the movable main contact 18 and the movable contact rod 7. The sliding conductive cylinder can not only play a role in conductive connection, but also play a certain supporting role.

In this embodiment, the moving contact rod 7 is inserted into the moving main contact 18 in a manner of relatively sliding along the front-rear direction, a packing support part is fixedly arranged at the middle position of the inner side of the moving main contact 18, a through hole is arranged at the center of the packing support part, and the moving contact rod 7 is inserted into the through hole along the front-rear direction in a guiding manner. The packing support part specifically comprises a support ring 16, a fixed flange 9 and a guide sleeve 10, the support ring 16 is fixedly arranged on the inner side wall of the movable main contact 18, the fixed flange 9 is welded on the rear side surface of the support ring 16, the guide sleeve 10 is fixedly connected on the rear side of the fixed flange 9, and hole sections which are mutually communicated are arranged on the support ring 16, the fixed flange 9 and the guide sleeve 10 so as to form a through hole of the packing support part for the movable contact rod 7 to pass through.

The front end of the movable contact rod 7 is fixedly provided with a movable arc contact 5, and the interior of the movable arc contact 5 is of a coil structure and is used for being disconnected with the static arc contact 4 to extinguish arc. In order to improve the breaking performance, the coil structures arranged in the movable arc contact 5 and the static arc contact 4 generate longitudinal magnetic fields, and the arc extinguishing device has strong breaking and arc extinguishing capabilities.

Specifically, the movable contact rod 7 extends in the front-rear direction as a whole and comprises a contact rod main body, a movable terminal 11 and a transmission connecting rod, the movable terminal 11 and the transmission connecting rod are arranged at the rear part of the contact rod main body, the movable arc contact 5 is fixed at the front end of the contact rod main body, the movable terminal 11 is assembled in a corresponding sliding conductive cylinder in a sliding manner in the front-rear direction and is in conductive connection with the spring contact finger 13, and then the movable contact rod 7 and the movable main contact 18 are in conductive connection.

Move terminal 11 and contact stick main part conductive connection, it is concrete, set up the toper arch in contact stick main part rear end, then set up the toper sunken in moving terminal 11 front end, the toper arch corresponds with the toper sunken to coincide and inserts the cooperation, not only conveniently inserts the cooperation, can effectively increase the through-flow area moreover.

The transmission connecting rod is specifically a connecting screw rod 12, the connecting screw rod 12 is in threaded connection with the rear end of the contact rod main body, a nut can be screwed on the connecting screw rod 12, the nut pushes the terminal 11 forwards, and the connecting screw rod 12, the movable terminal 11 and the contact rod main body can be fixedly assembled together.

The connecting screw 12 is used as an arc contact driving part and is positioned at the rear side of the movable contact rod 7 and is used for being in transmission connection with a corresponding arc contact driving mechanism 200, so that the movable contact rod 7 and the movable arc contact 5 can move back and forth relative to the movable main contact 18 and the shell 2. Correspondingly, the connection screw 12 may also be a metal rod, and at this time, an insulating pull rod needs to be disposed on the arc contact driving mechanism 200 to be in transmission connection with the metal rod, so as to ensure an insulating effect. Of course, in other embodiments, the connecting screw itself may employ an insulator having some supporting rigidity.

In the embodiment, as the movable contact rod 7, the movable main contact 18 and the shell 2 can relatively slide in the front and back direction, in order to ensure the air tightness of the vacuum arc extinguish chamber, the inner blocking corrugated pipe 8 is arranged, and the inner blocking corrugated pipe 8 is blocked and connected between the movable contact rod 7 and the movable main contact 18. The inner plugging corrugated pipe 8 axially extends along the front-back direction, the inner plugging corrugated pipe 8 is sleeved on the movable contact rod 7, the rear end of the inner plugging corrugated pipe is fixedly connected with the support ring 16 in a sealing mode, the front end of the inner plugging corrugated pipe is fixedly connected on the bottom wall of the inner shielding cover 6 in a sealing mode, actually, the inner shielding cover 6 is fixedly connected at the front end of the inner plugging corrugated pipe 8 and located on the rear side of the moving arc contact 5, the inner shielding cover 6 is sleeved on the movable contact rod 7, the movable contact rod 7 is provided with a stopping step, the step surface of the stopping step is arranged backwards and used for being matched with the bottom wall stop of the inner shielding cover 6, and then the inner shielding cover 6 is fixed on the movable contact rod 7 through the matching of the stopping step and the. The inner shield cover 6 is in sealing fit with the movable contact rod 7, and sealing assembly of the inner shield cover 6 and the movable contact rod 7 is achieved.

In addition, because the inner plugging corrugated pipe 8 is positioned between the movable contact rod 7 and the movable main contact 18, and the front end of the inner plugging corrugated pipe 8 is arranged close to the front end of the movable main contact 18, in order to prevent the front tip of the inner plugging corrugated pipe 8 from influencing the internal electric field, the inner shielding cover 6 is provided with a rear cylinder shielding section which is folded and extended backwards, the rear cylinder shielding section at least covers the front part of the inner plugging corrugated pipe 8 from front to back, and also can cover the middle part and the rear part of the inner plugging corrugated pipe, as long as when the movable main contact 18 and the movable arcing contact 5 move relatively, the rear cylinder shielding section cannot interfere with the support ring 16 to influence the normal compression of the inner plugging corrugated pipe 8.

The vacuum arc-extinguishing chamber that this embodiment provided arranges from top to bottom when using, and quiet end is located the top usually, and quiet main contact, quiet arc contact set firmly on quiet contact stick, and then are together fixed with quiet apron. The movable end of the arc extinguish chamber is usually positioned below, the movable main contact and the movable arc contact are supported in the shell through the corresponding plugging corrugated pipes, and in addition, when the arc extinguish chamber is used, the movable main contact and the movable arc contact can be in transmission connection with the corresponding driving mechanisms, the corresponding driving mechanisms can also improve certain supporting acting force, and the action stability of the movable main contact and the movable arc contact is ensured.

As shown in fig. 1, in the fully open state, the moving main contact 18 and the stationary main contact 22 maintain a main contact opening distance, and the moving arcing contact 5 and the stationary arcing contact 4 maintain an arcing contact opening distance (i.e., an insulation opening distance), which is generally greater than the arcing contact opening distance. Under the condition of keeping a set opening distance, the movable arc contact 5 protrudes forwards from the movable main contact 18, and in order to reduce the front and rear axial lengths of the vacuum arc extinguish chamber, the movable arc contact 5 can extend and be inserted into the static main contact 22, that is, when the movable arc contact 5 and the static arc contact 4 complete the switching-off and arc extinguishing operations, the movable arc contact 5 can be positioned in the static main contact 22, so that the static contact sleeve section absorbs arc post-arc products generated by electric arcs. At this time, of course, the arc-isolating gap is kept between the movable arc contact 5 and the static main contact 22.

In fact, since the arc contact opening distance between the moving arc contact 5 and the fixed contact is the insulation opening distance, generally speaking, the arc extinguishing opening distance between the two arc contacts is smaller than the insulation opening distance between the two arc contacts, so long as it is ensured that when the arc extinguishing opening distance is formed between the moving arc contact 5 and the fixed arc contact 4 (at this time, the arc extinguishing can be achieved), the moving arc contact 5 is still located inside the fixed main contact 22, after the arc extinguishing by switching off, the moving arc contact 5 will continue to move backwards until the set arc contact opening distance (i.e., the insulation opening distance) is reached, at this time, the moving arc contact 5 can be located inside the fixed main contact 22, and can also exit the fixed main contact 22 backwards. In any case, it is necessary that the static contact sleeve segment of the static main contact 22 has a sufficient length, so that the static main contact 22 has a set length, so that the rear end of the static contact sleeve segment has a set distance from the front end of the static arc contact 4, and it is ensured that the moving arc contact 5 is matched with the static arc contact 4 to realize the on-off arc extinguishing before exiting the static contact sleeve segment backwards, so that the static contact sleeve segment absorbs the post-arc product generated by the arc.

In the process of closing operation, as shown in fig. 2, the main contact driving mechanism 100 and the arcing contact driving mechanism 200 may be driven synchronously at the beginning, so that the movable main contact 18, the movable contact rod 7 and the movable arcing contact 5 move synchronously until the movable arcing contact 5 is in contact with the stationary arcing contact 4 in a closing manner, at this time, the arcing contact driving mechanism 200 stops outputting, the movable contact rod 7 and the movable arcing contact 5 stop moving, in the process, the outer plugging corrugated tube 15 stretches and deforms, the stretching distance of the outer plugging corrugated tube 15 is consistent with the opening distance of the arcing contacts, and the length of the inner plugging corrugated tube 8 is unchanged.

Then, as shown in fig. 3, the main contact driving mechanism 100 continues to drive the movable main contact 18 to move forward until the movable main contact 18 is in close contact with the stationary main contact 22, in this process, the outer plugging bellows 15 continues to stretch, while the inner plugging bellows 8 is compressed and deformed, the compressed storage of the inner plugging bellows 8 is equal to the difference between the opening distance of the main contact and the opening distance of the arcing contact, and in the whole closing process, the stretching amount of the outer plugging bellows 15 is equal to the opening distance of the main contact.

After the circuit is completely closed, the resistance of the main contact closed loop is smaller than that of the arc contact closed loop, so that the current is conducted through the main contact loop, and the through-current capacity of the whole conductive loop can be effectively improved. And when the vacuum arc-extinguishing chamber is switched on, the two arc contacts are closed first, and the main contact is opened and closed, so that abnormal phenomena such as pre-breakdown and the like generated in the switching-on process can be avoided.

During the opening operation, as shown in fig. 4, the main contact driving mechanism 100 drives the movable main contact 18 to move backward, the movable main contact 18 is disconnected from the stationary main contact 22, in the process, the movable arcing contact 5 and the stationary arcing contact 4 are still in a conducting state, the main contact and the arcing contact are in the same potential, the arcing condition between the movable main contact 18 and the stationary main contact 22 cannot occur, in the process, the inner plugging corrugated pipe 8 is stretched to be lengthened, and the outer plugging corrugated pipe 15 is compressed to be shortened.

As shown in fig. 5, during the opening process, when the movable main contact 18 retreats until the distance between the movable main contact 18 and the fixed main contact 22 is equal to the difference between the main contact opening distance and the arcing contact opening distance, the arcing contact driving mechanism 200 and the main contact driving mechanism 100 synchronously act, the movable main contact 18 and the movable arcing contact 5 synchronously retreat until the main contact opening distance and the arcing contact opening distance both reach the rated opening distance, and then the movement is stopped. In the process, the length of the inner plugging bellows 8 is not changed, and the outer plugging bellows 15 continues to be shortened.

When the movable arc contact and the static arc contact 4 are disconnected, electric arcs can be generated between the movable arc contact and the static arc contact 4, and due to the fact that coil structures are arranged inside the two arc contacts, the generated magnetic field can effectively control the electric arcs to achieve the on-off arc extinction.

In the vacuum arc-extinguishing chamber provided by the embodiment, the rear part of the movable main contact 18 is provided with a main contact driving part for being in transmission connection with the corresponding main contact driving mechanism 100, the rear part of the movable contact rod 7 is provided with an arc contact driving part for being in transmission connection with the corresponding arc contact driving mechanism 200, the movable main contact 18 and the movable arc contact 5 can be driven to move back and forth independently through two sets of driving mechanisms, and the moving speed of the movable contact rod 7 and the movable main contact 18 is controlled. When the vacuum arc extinguish chamber is switched on, the movable arc contact 5 is in conductive contact with the static arc contact 4, and then the movable main contact 18 is in conductive contact with the static main contact 22, so that normal through flow is realized. When the vacuum arc extinguish chamber is opened, the movable main contact 18 and the static main contact 22 can be opened and the movable arc contact 5 and the static arc contact 4 can be opened and arc-extinguished after the movable main contact and the static main contact are opened and closed, so that the through-current capacity of the vacuum arc extinguish chamber can be effectively improved, the contradiction that the high opening and closing capacity and the high-current capacity can not be managed simultaneously is solved, and the application market of the high-voltage-level vacuum arc extinguish chamber is effectively widened.

And because the movable arc contact and the movable arc contact can move back and forth relatively independently and respectively, the static main contact, the static arc contact and the static contact rod can be set into a fixed structure, a motion space does not need to be reserved on one side of the static end of the vacuum arc extinguish chamber, the requirement on the application space can be further reduced, and the movable arc contact and the static arc contact can be applied to installation places with relatively strict space requirements.

The specific embodiment 2 of the vacuum arc-extinguishing chamber provided by the invention is as follows:

the difference from example 1 is mainly that: in embodiment 1, the coil structures inside the moving arc contact and the fixed arc contact generate longitudinal magnetic fields, so as to obtain a strong arc extinguishing effect. In the embodiment, the movable arc contact and the static arc contact can generate a transverse magnetic field to realize the on-off arc extinction.

Of course, in other embodiments, on the basis of ensuring the arc extinction, the moving arc contact and the static arc contact may also adopt other existing arc contacts capable of achieving the breaking arc extinction, such as: the U-shaped longitudinal magnetic field contact structure is adopted, although the magnetic field uniformity is poor, the longitudinal magnetic field is strong, and the U-shaped longitudinal magnetic field contact structure has certain arc extinguishing performance.

The specific embodiment 3 of the vacuum arc-extinguishing chamber provided by the invention is as follows:

the difference from example 1 is mainly that: in the embodiment 1, the rear end of the inner plugging corrugated pipe is hermetically and fixedly connected to the support ring, so that the inner plugging corrugated pipe is indirectly plugged between the movable main contact and the movable contact rod. In this embodiment, the rear end of the inner sealing bellows may also be directly welded to the inside of the movable main contact, and the front end of the inner sealing bellows may also be directly welded to the outer peripheral surface of the movable contact rod, so that the inner sealing bellows is directly sealed between the movable main contact and the movable contact rod.

The specific embodiment 4 of the vacuum arc-extinguishing chamber provided by the invention is as follows:

the difference from example 1 is mainly that: in embodiment 1, the moving contact rod is supported and arranged inside the moving main contact through the packing support part, and the packing support part is fixedly arranged inside the moving main contact, so that the moving contact rod is conveniently supported. In this embodiment, the sealing support portion is omitted, a guide support frame is added to the movable cover plate, the movable contact rod is movably supported and assembled on the guide support frame along the front-back direction, and therefore relatively independent reciprocating movement between the movable main contact and the movable contact rod can be achieved.

The specific embodiment 5 of the vacuum arc-extinguishing chamber provided by the invention is as follows:

the difference from example 1 is mainly that: in embodiment 1, an inner shield is provided, and a rear cylinder shield section on the inner shield is sleeved on the front part of the inner plugging corrugated pipe to prevent the tip discharge. In this embodiment, if the outer periphery of the front end of the inner plugging corrugated pipe is a smooth surface, the inner shield can be omitted. Or when the front end of the inner plugging corrugated pipe is far away from the movable main contact, the inner shielding cover can be omitted.

The specific embodiment 6 of the vacuum interrupter provided by the present invention:

the difference from example 1 is mainly that: in embodiment 1, the inner shield is directly fixed to the front end of the inner plugging corrugated pipe, and the inner shield is effectively positioned by the cooperation of the stop step on the movable contact rod and the inner plugging corrugated pipe. In this embodiment, the inner shield can be directly welded and fixed on the moving contact rod in advance, and then the front end of the inner plugging corrugated pipe is welded and connected on the moving contact rod, so long as the inner shield can be sleeved on the front part of the inner plugging corrugated pipe to play a good protection role.

The specific embodiment 7 of the vacuum interrupter provided by the present invention:

the difference from example 1 is mainly that: in embodiment 1, the movable contact rod includes a contact rod main body and a movable terminal which are separately assembled, and a transmission connecting rod is provided at the rear of the movable contact rod to implement a transmission mechanism with the arc contact driving mechanism. In this embodiment, the contact rod main body and the movable terminal are of an integrated structure, and a connecting pin shaft is arranged at the rear part of the movable contact rod and is used as an arc contact driving part and is in transmission connection with an arc contact driving mechanism.

The specific embodiment 8 of the vacuum interrupter provided by the present invention:

the difference from example 1 is mainly that: in embodiment 1, the stationary main contact and the stationary arcing contact are fixed to a stationary contact bar, and the stationary contact bar is fixedly mounted to the stationary cover plate so as to be relatively fixed to the housing. In this embodiment, the static contact component may also adopt a structure of a static contact rod 3, a static conductive rod, a static main contact and a static longitudinal magnetic field contact (i.e. a static arc contact) in the vacuum arc-extinguishing chamber disclosed in the chinese patent application with application publication No. CN111463061A, the static contact rod 3 is a sleeve structure, one end of the static contact rod is fixed on the housing, the other end of the static contact rod is fixedly provided with the static main contact for electrically conducting contact with the dynamic main contact to realize normal through-flow, one end of the static conductive rod is correspondingly and fixedly provided with the static longitudinal magnetic field contact to open and close the arc with the corresponding dynamic arc contact, at this time, the static conductive rod can move up and down relative to the housing and the static contact rod 3, so that the static arc contact can move up and down to meet the position requirements of closing contact and opening.

Certainly, in other embodiments, the static contact component may also adopt a structure such as a static main contact, an upper moving conductive rod, an upper guide sleeve and the like in the authorization publication No. CN100555496C, and a static arc contact is disposed at a corresponding end of the upper moving conductive rod, and specific structures are not described herein again.

That is to say, quiet arc contact in the quiet contact subassembly can the oscilaltion to satisfy the position demand of closing a floodgate contact and separating brake arc extinguishing can, of course, can have certain requirement to the installation space of using the place this moment.

The embodiment of the vacuum circuit breaker provided by the invention comprises the following components:

as shown in fig. 1, the vacuum circuit breaker in this embodiment includes a vacuum arc-extinguishing chamber, a main contact driving mechanism and an arc contact driving mechanism, where the structure of the vacuum arc-extinguishing chamber is the same as that in the above-mentioned vacuum arc-extinguishing chamber embodiment 1, and details are not repeated herein, the main contact driving mechanism may employ an electromagnetic operating mechanism, and only an output portion of the electromagnetic operating mechanism is in transmission connection with a main contact driving portion at the rear side of a moving main contact of the vacuum arc-extinguishing chamber, and the arc contact driving mechanism may employ another set of electromagnetic operating mechanism, and only an output portion of the electromagnetic operating mechanism is in transmission connection with a contact driving portion at the rear side of a moving contact rod of the vacuum arc-extinguishing chamber, so that the moving contact rod, the moving arc contact and the moving main contact can independently move back and forth relative to the housing, so that when the vacuum arc-extinguishing chamber is switched on, the moving arc contact and the static arc contact are, the movable main contact is in conductive contact with the static main contact to realize normal through-flow; when the vacuum arc-extinguishing chamber is opened, the movable main contact and the static main contact are opened, and then the movable arc contact and the static arc contact are opened to extinguish arc.

In this embodiment, the vacuum interrupter in the vacuum circuit breaker adopts the interrupter structure in the vacuum interrupter embodiment 1, and in other embodiments, the interrupter structure in any one of the vacuum interrupter embodiments 2 to 8 may be adopted.

In this embodiment, the main contact driving mechanism and the arc contact driving mechanism both adopt electromagnetic operating mechanisms. In other embodiments, the main contact driving mechanism and the arcing contact driving mechanism may be different driving mechanisms, such as a pneumatic operating mechanism, a hydraulic operating mechanism, etc., or other driving mechanisms capable of driving the arcing contact and the main contact to reciprocate.

The embodiment of the switching-on and switching-off control method of the vacuum circuit breaker provided by the invention comprises the following steps:

as shown in figure 1, in a vacuum arc-extinguishing chamber, a movable contact rod and a movable arc contact can move back and forth relative to a movable main contact and a shell of the vacuum arc-extinguishing chamber, the movable main contact can move back and forth relative to the shell of the vacuum arc-extinguishing chamber, at the moment, the movable main contact can be driven by a main contact driving mechanism to independently move back and forth, the movable contact rod and the movable arc contact can be driven by an arc contact driving mechanism to independently move back and forth, double-acting operation is realized, and the arc-extinguishing of the main contact before the arc contact is in closing and after the arc contact is in opening can be effectively met.

Of course, from the embodiment 1 of the vacuum arc-extinguishing chamber, when the switching-on operation is performed, the moving contact rod and the moving arc contact move forward synchronously with the moving main contact first until the moving arc contact is in conductive contact with the static arc contact, and then the moving main contact moves forward independently until the moving main contact is in conductive contact with the static main contact, so that normal through-flow is realized.

When the switching-off operation is carried out, the movable main contact independently moves backwards for a set distance to be disconnected with the static main contact, and then the movable main contact, the movable contact rod and the movable arc contact synchronously move backwards again, so that the movable arc contact and the static arc contact are disconnected and arc-extinguishing.

In other embodiments, of course, in the initial stage of the closing motion, the movable main contact and the movable contact rod may also move asynchronously, so that when the movable arcing contact is in contact with and conducted with the stationary arcing contact, the movable main contact and the stationary main contact are not yet in contact, and then the main contact driving mechanism may normally drive the movable main contact to move forward until the movable main contact is in contact with and closed with the stationary main contact, thereby completing the closing operation.

Correspondingly, in the process of opening the brake, the movable main contact can be moved back firstly in the early stage of opening the brake to form a certain opening distance with the static main contact, and the movable main contact and the movable contact rod can also move asynchronously in the later stage of opening the brake, so long as the arc discharge is ensured to occur between the arc contacts and the arc contacts break to extinguish the arc.

Finally, although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described in the foregoing embodiments without departing from the inventive concept, or some of the technical features may be replaced with equivalents. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. Vacuum interrupter, includes:

a housing extending in a front-rear direction;

the movable main contact is in a sleeve shape, is sleeved outside the movable arc contact at intervals, and can reciprocate in the front-back direction relative to the shell;

2. The vacuum arc-extinguishing chamber as claimed in claim 1, characterized in that a packing support part is fixedly arranged inside the moving main contact, a through hole is arranged in the center of the packing support part, and the moving contact rod is inserted into the through hole along the front-back direction.

3. The vacuum interrupter as claimed in claim 2, wherein one end of the inner sealing bellows is attached to the sealing support to indirectly seal the movable contact rod and the movable main contact.

4. The vacuum interrupter as claimed in claim 1, 2 or 3, wherein the moving contact rod is fixedly sleeved with an inner shield at the rear side of the moving arc contact, the inner shield has a rear barrel shielding section folded and extended backward, and the rear barrel shielding section covers at least the front part of the inner sealing bellows from front to back.

5. The vacuum arc-extinguishing chamber according to claim 4, characterized in that the inner shield is fixedly connected with the front end of the inner plugging corrugated pipe, and the inner shield is in sealing fit with the movable contact rod so as to realize the sealing assembly of the inner shield and the movable contact rod; the movable contact rod is provided with a stop step, the step surface of the stop step is arranged backwards, and the stop step is in stop fit with the inner shield cover so as to be matched with the inner plugging corrugated pipe to fix the inner shield cover on the movable contact rod.

6. The vacuum interrupter according to claim 1, 2 or 3, wherein the moving contact rod comprises a contact rod main body, a moving terminal and a transmission connecting rod are arranged at the rear part of the contact rod main body, the moving arc contact is fixed at the front end of the contact rod main body, the moving main contact is provided with a sliding conductive cylinder, the moving terminal is slidably assembled in the sliding conductive cylinder along the front-back direction, a spring contact finger is arranged in the sliding conductive cylinder to realize the conductive connection between the moving main contact and the moving contact rod, the transmission connecting rod is fixedly connected with the moving terminal or the contact rod main body, and the transmission connecting rod is used as the arc contact driving part and is in transmission connection with the arc contact driving mechanism.

7. The vacuum interrupter according to claim 1, 2 or 3, wherein the vacuum interrupter includes a stationary contact rod extending in a front-rear direction, the stationary arc contact is located at a rear end of the stationary contact rod, the stationary main contact is fixedly sleeved outside the stationary contact rod, the stationary main contact has a stationary contact sleeve section, the stationary contact sleeve section is sleeved outside the stationary arc contact at an interval, the rear end of the stationary contact sleeve section is used for electrically contacting with the moving main contact, the stationary main contact has a set length, so that a set distance is formed between the rear end of the stationary contact sleeve section and a front end of the stationary arc contact, and it is ensured that the moving arc contact is engaged with the stationary arc contact to achieve breaking and extinguishing before exiting the stationary contact sleeve section backwards, so that the stationary contact sleeve section absorbs post-arc products generated by the arc.

8. Vacuum interrupter, comprising:

vacuum interrupter, characterized in that the vacuum interrupter is a vacuum interrupter according to any of claims 1 to 7;

the vacuum circuit breaker also comprises a main contact driving mechanism and an arc contact driving mechanism;

the main contact driving mechanism is in transmission connection with a main contact driving part at the rear side of a movable main contact of the vacuum arc-extinguishing chamber and can drive the movable arc contact to move back and forth relative to the movable contact rod and the movable arc contact;

the arc contact driving mechanism is in transmission connection with an arc contact driving part at the rear side of a movable contact rod of the vacuum arc-extinguishing chamber and can drive the movable contact rod and the movable arc contact to move back and forth relative to the movable main contact.

9. The switching-on and switching-off control method of the vacuum circuit breaker is characterized in that in a vacuum arc extinguish chamber, a movable contact bar and a movable arc contact can move back and forth relative to a movable main contact and a shell of the vacuum arc extinguish chamber, and the movable main contact can move back and forth relative to the shell of the vacuum arc extinguish chamber;

10. The vacuum circuit breaker opening and closing control method according to claim 9, wherein when closing operation is performed, the moving contact rod and the moving arc contact move forward synchronously with the moving main contact first until the moving arc contact is in conductive contact with the stationary arc contact, and then the moving main contact moves forward independently until the moving main contact is in conductive contact with the stationary main contact, so that normal through-flow is realized;