CN107527773B

CN107527773B - Universal circuit breaker with arc extinguishing performance

Info

Publication number: CN107527773B
Application number: CN201710727750.2A
Authority: CN
Inventors: 张珂; 张信明
Original assignee: Hebei Bao Kay Electric Co ltd
Current assignee: Hebei Bao Kay Electric Co ltd
Priority date: 2017-08-23
Filing date: 2017-08-23
Publication date: 2020-02-18
Anticipated expiration: 2037-08-23
Also published as: CN107527773A

Abstract

A universal circuit breaker with arc extinguishing performance comprises a fixed contact, a movable contact and an insulating arc extinguishing mechanism which are arranged in a breaker shell, wherein the insulating arc extinguishing mechanism comprises an insulating shielding plate, an armature, a magnetic yoke, a sliding rod and a pressure spring, and the magnetic yoke is fixed on one side of the fixed contact of the circuit breaker and is lower than a contact surface of the fixed contact and the movable contact; the insulating shielding plate and the armature are positioned on the other side of the static contact, and the insulating shielding plate is fixed on the armature and corresponds to a gap between a moving contact and the static contact of the circuit breaker; one end of the sliding rod is fixedly connected with the magnetic yoke, and the other end of the sliding rod penetrates through the pressure spring and the armature in sequence and then is screwed into the anti-falling nut. The insulation shielding plate can be quickly inserted between the moving contact and the static contact when the breaker breaks the short-circuit current, so that the electric arc between the moving contact and the static contact is extinguished, short flashover or no flashover of the breaker is realized, the capacity of breaking alternating-current and direct-current short-circuit currents of the breaker is greatly improved, and the application range of the breaker is expanded.

Description

Universal circuit breaker with arc extinguishing performance

Technical Field

The invention relates to an alternating current and direct current universal circuit breaker with strong short-circuit current breaking capacity, belonging to the technical field of emergency protection devices.

Background

The conventional circuit breaker (ACB) is an important electrical component in industrial and civil low-voltage distribution equipment, and is mostly used as a master switch on the low-voltage side of a low-voltage distribution system to protect overload and short-circuit faults of a distribution line. The short-circuit fault protection is the most important function, and because the short-circuit current of a line is very large during short-circuit fault, plasma electric arcs with very large energy can be generated between a moving contact and a static contact of the breaker when the breaker breaks the short-circuit current, and the breaker can complete the task of breaking the short-circuit current only by quickly extinguishing the electric arcs through certain technical measures.

At present, ACBs at home and abroad adopt an arc extinguishing chamber technology to cool and extinguish high-temperature and high-voltage electric arcs generated when short-circuit current is disconnected, and the arc extinguishing principle of the technology is as follows: when the short-circuit current is cut off, after the electric arc is generated between the moving contact and the static contact and is stretched to a certain length and the energy is correspondingly amplified, the high-energy electric arc is driven to enter the arc extinguish chamber by adopting magnetic field electrodynamic force or other modes, so that the high-energy electric arc is extinguished under the cooling action of the metal grid sheet in the arc extinguish chamber. The arc extinguishing effect of the method is influenced by factors such as arc extinguishing chamber materials, contact opening speed, contact opening distance, contact materials and the like, particularly for the circuit breaker with a single-breakpoint structure, the capacity of breaking short-circuit current is poor and generally does not exceed the alternating current 400V and 50-80kA, and if the performance parameter is improved, the manufacturing cost is greatly improved. And the direct current short-circuit current is not easy to break because of no zero-crossing process.

With the construction and development of a power grid and the improvement of the reliability requirement of people on the power grid, a new arc extinguishing scheme is objectively needed to greatly improve the capacity of the ACB for breaking alternating current and direct current short-circuit current.

Disclosure of Invention

The invention aims to provide a universal circuit breaker with arc extinguishing performance aiming at the defects of the prior art so as to improve the capacity of the universal circuit breaker for breaking short-circuit current and expand the application range of the universal circuit breaker.

The problem of the invention is realized by the following technical scheme:

a universal circuit breaker with arc extinguishing performance comprises a shell, a fixed contact, a moving contact, a tripping mechanism and an arc extinguishing chamber, wherein after improvement, the universal circuit breaker is additionally provided with an insulating arc extinguishing mechanism, the insulating arc extinguishing mechanism comprises an insulating shielding plate, an armature, a magnetic yoke, a sliding rod and a pressure spring, and the magnetic yoke is fixed on one side of the fixed contact of the circuit breaker and is lower than a contact surface of the fixed contact and the moving contact; the insulating shielding plate and the armature are positioned on the other side of the static contact, and the insulating shielding plate is fixed on the armature and corresponds to a gap between a moving contact and the static contact of the circuit breaker; one end of the sliding rod is fixedly connected with the magnetic yoke, and the other end of the sliding rod penetrates through the pressure spring and the armature in sequence and then is screwed into the anti-falling nut.

Above-mentioned universal circuit breaker with arc extinguishing performance, slide bar and pressure spring all set up two, and they symmetry sets up the both sides at the circuit breaker static contact.

According to the universal circuit breaker with the arc extinguishing performance, the insulating shielding plate is in a dustpan shape and is placed upside down, the front end of the insulating shielding plate corresponds to a gap between a moving contact and a static contact of the circuit breaker, and the back plate penetrates through the sliding rod and is fixedly connected with the armature.

The universal circuit breaker with arc extinguishing performance is characterized in that a tripping mechanism, an energy storage mechanism, an intelligent control module and a magnetic flux tripper are further arranged in the breaker shell.

The invention adds the insulation shielding plate as an auxiliary arc extinguishing mechanism, the auxiliary arc extinguishing mechanism can rapidly act at the moment that the breaker breaks the short-circuit current and is inserted between the moving contact and the static contact, and the electric arc just generated between the moving contact and the static contact is extinguished or reduced, so that the amplification time of electric arc energy is shortened, the concentration of electric arc energy is reduced, and the short flashover or no flashover of the breaker is realized. The invention adopts two-stage arc extinction, and the electric arc after the initial auxiliary arc extinction can be introduced into the arc extinction chamber to continue the subsequent arc extinction operation, thereby greatly improving the arc extinction capability of the circuit breaker and greatly improving the short-circuit current breaking capability of the circuit breaker.

Drawings

FIG. 1 is a schematic diagram of the closing state of the present invention;

FIG. 2 is a schematic diagram illustrating an instant state of opening the gate according to the present invention;

FIG. 3 is a schematic diagram illustrating the completion state of the opening operation of the present invention;

FIG. 4 is a schematic diagram of an insulating arc-quenching mechanism;

FIG. 5 is a schematic diagram of the operation of the intelligent control module and the magnetic flux release;

FIG. 6 is a schematic view of the structure of the dielectric shield;

fig. 7 is a left side view of fig. 6.

The list of labels in the figure is: 1. static contact; 2. a moving contact; 3. a magnetic yoke; 4. an insulating shield plate; 5. an armature; 6. a pressure spring; 7. a slide bar; 8. a tripping mechanism; 9. an energy storage mechanism; 10. intelligent control module and magnetic flux release, CT, current transformer; A. and (7) a pin shaft.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

The invention adds a special insulation arc-extinguishing mechanism on the static contact side of the universal circuit breaker (ACB), when the circuit has fault and short circuit current, the intelligent controller module of the circuit breaker sends out instantaneous tripping command and the action mechanism acts instantaneously, and the insulation shielding plate of the insulation arc-extinguishing mechanism inserts between the moving head and the static head quickly, thus playing a role of high-efficiency arc-extinguishing instantaneously.

Referring to fig. 1 to 7, the invention includes a fixed contact 1, a movable contact 2, a tripping mechanism 8, an energy storage mechanism 9, an insulating arc extinguishing mechanism, an intelligent control module and a magnetic flux tripper 10, which are arranged on a circuit breaker housing, wherein the insulating arc extinguishing mechanism includes a magnetic yoke 3, an insulating shielding plate 4, an armature 5, a pressure spring 6 and a slide bar 7.

The insulating arc extinguishing mechanism adopts a slide bar type structure, two slide bars 7 are fixed on the static contact 1 through a magnet yoke 3 and screws, two pressure springs 6 are arranged on the two slide bars 7, an armature 5 and an insulating shielding plate 4 are fixed into a whole through screws and are arranged on the two slide bars 7, the end parts of the two slide bars 7 are provided with anti-drop nuts for limiting the combination of the armature 5 and the insulating shielding plate 4 and preventing the two from dropping off from the slide bars 7, and the combination of the armature 5 and the insulating shielding plate 4 can overcome the elasticity of the pressure springs 6 to slide towards the static contact 1 and one side of the magnet yoke 3 under the action of external force. When a fault short-circuit current occurs in a circuit, because a strong electromagnetic field is generated around the static contact 1, the magnetic yoke 3 attracts the armature 5 after being magnetized, a combination of the armature 5 and the insulating shielding plate 4 overcomes the elasticity of the pressure spring 6 and slides to one side of the static contact 1 and the magnetic yoke 3 rapidly, meanwhile, an intelligent control module and a magnetic flux release 10 of the switch send out an instant release instruction according to the collected information of the current transformer CT and act instantaneously to cause the release mechanism 8 to act, and when the moving contact 2 rotates clockwise around the pin shaft A to be opened, the insulating shielding plate 4 is rapidly inserted between the moving contact 2 and the static contact 1 to play a role of rapidly insulating and shielding arc extinguishing. After the short-circuit current disappears, the attraction force borne by the armature 5 disappears, the combination body of the armature 5 and the insulating shielding plate 4 returns to the original position under the action of the elastic force of the pressure spring 6, and the circuit breaker completes the whole process of breaking the short-circuit current. The energy storage mechanism 9 is used for closing and storing energy.

The insulating shielding plate 4 is used as an auxiliary arc extinguishing mechanism to form a two-stage arc extinguishing device with the original arc extinguishing chamber, the auxiliary arc extinguishing mechanism is used for extinguishing arcs when the moving contact and the static contact are not completely opened, and the arc extinguishing chamber 15 has a good residual arc extinguishing effect after the moving contact and the static contact are completely opened.

The insulation shielding plate 4 is made of high-strength and high-temperature-resistant engineering plastic materials. The number of times (3 times at most) of effectively breaking the short-circuit current specified by the product standard can be ensured.

Due to the adoption of the technical scheme, the arc extinguishing device of the ACB can achieve the following technical progress:

1, the capacity of breaking short-circuit current of a product can be greatly improved;

2. the purpose of alternating current and direct current is achieved;

3. when the fault short-circuit current is cut off, the further expansion of the arc energy can be limited, so that short arcing or no arcing of the product can be realized.

Claims

1. A universal circuit breaker with arc extinguishing performance comprises a shell, a static contact, a moving contact, a tripping mechanism and an arc extinguishing chamber, and is characterized in that the universal circuit breaker is additionally provided with an insulating arc extinguishing mechanism, the insulating arc extinguishing mechanism comprises an insulating shielding plate (4), an armature (5), a magnetic yoke (3), a sliding rod (7) and a pressure spring (6), and the magnetic yoke (3) is fixed on one side of the static contact (1) of the circuit breaker and is lower than the contact surface of the static contact (1) and the moving contact (2); the insulation shielding plate (4) and the armature (5) are positioned on the other side of the static contact (1), and the insulation shielding plate (4) is fixed on the armature (5) and corresponds to a gap between the moving contact (2) and the static contact (1) of the circuit breaker; one end of the sliding rod (7) is fixedly connected with the magnetic yoke (3), and the other end of the sliding rod penetrates through the pressure spring (6) and the armature (5) in sequence and then is screwed into the anti-falling nut;

a tripping mechanism (8), an energy storage mechanism (9), an intelligent control module and a magnetic flux tripper (10) are further arranged in the shell of the circuit breaker.

2. Universal circuit breaker with arc quenching properties according to claim 1, characterized in that two sliding rods (7) and two compression springs (6) are provided, symmetrically arranged on both sides of the stationary contact (1) of the circuit breaker.

3. Universal circuit breaker with arc quenching function according to claim 1 or 2, characterized in that the insulating shielding plate (4) is in the shape of an upside-down dustpan, the front end of which corresponds to the gap between the moving contact (2) and the stationary contact (1) of the circuit breaker, and the backplate is threaded on the sliding rod (7) and is fixedly connected to the armature (5).