CN216389232U - Circuit breaker - Google Patents

Abstract

A circuit breaker belongs to the technical field of low-voltage electrical appliances. The power electronic switch comprises a shell, wherein a first mechanical switching-off device, a second mechanical switching-off device and a power electronic switch are installed in the shell, the second mechanical switching-off device is connected with the power electronic switch in series, a formed series circuit is connected with the first mechanical switching-off device in parallel, the first mechanical switching-off device comprises a first moving contact and a first fixed contact, the second mechanical switching-off device comprises a second moving contact and a second fixed contact, the first moving contact comprises a plurality of first moving contact pieces, the second moving contact comprises a plurality of second moving contact pieces, when the first moving contact and the second moving contact are located at opening positions, the first moving contact pieces and the second moving contact pieces are located at the same opening angle, and in the opening process, the second moving contact and the second fixed contact are separated later than the first moving contact and the first fixed contact. The advantages are that: the switching between two paths of current is realized by improving the contact of the existing circuit breaker, the universality of parts is improved, and the cost is reduced.

Description

Circuit breaker

Technical Field

The utility model belongs to the technical field of low-voltage electric appliances, and particularly relates to a circuit breaker.

Background

With the annual increase of installed capacity of distributed energy and the increase of capacity of a power system, a direct current power grid becomes the development direction of a future power grid, however, the direct current system also faces many potential problems, and the most serious problem is direct current short circuit fault. Because the short-circuit impedance of a direct-current system is small, the fault current rises quickly, and impact can be caused to system equipment, and the direct-current circuit breaker is the most promising solution for realizing quick isolation of short-circuit faults.

In recent years, along with the continuous development of power electronic technology, a solid-state direct-current circuit breaker based on a gate turn-off device appears, which can realize non-arc breaking and is applied to certain occasions due to short action time, but compared with the traditional mechanical circuit breaker, the solid-state direct-current circuit breaker has the defects of large on-state loss, limited bearing capacity, inrush current resistance and weak overvoltage resistance, so that the solid-state direct-current circuit breaker has great limitation in application, and the traditional mechanical circuit breaker generates an electric arc when breaking a fault current, so that the electric arc needs to be extinguished before breaking the fault current, and the traditional mechanical circuit breaker is unreliable.

In view of the above-mentioned prior art, the applicant has made an advantageous design to provide a hybrid circuit breaker that combines the features of both solid-state dc circuit breakers and mechanical circuit breakers, and the solutions to be described below have been created in this context.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a circuit breaker which can give consideration to the characteristics of a solid-state direct current circuit breaker and a mechanical circuit breaker, and has the advantages of low cost, reliable structure and high universality.

The utility model aims to achieve the aim, and the breaker comprises a shell, wherein a first mechanical breaking device, a second mechanical breaking device and a power electronic switch are arranged in the shell, the breaker also comprises an operating mechanism, the operating mechanism drives the first mechanical breaking device and the second mechanical breaking device to act, a series loop formed by the second mechanical breaking device and the power electronic switch which are connected in series is connected with the first mechanical breaking device in parallel, the first mechanical breaking device comprises a first moving contact and a first fixed contact matched with the first moving contact, the second mechanical breaking device comprises a second moving contact and a second fixed contact matched with the second moving contact, the first moving contact comprises a first moving contact, the second moving contact comprises a second moving contact, when the first moving contact and the second moving contact are in an opening position, the first moving contact piece and the second moving contact piece are positioned at the same opening angle, and in the opening process, the separation of the second moving contact and the second fixed contact is later than that of the first moving contact and the first fixed contact.

In a specific embodiment of the present invention, when the first movable contact and the second movable contact are in the closed position, the first movable contact piece and the second movable contact piece have an angle difference.

In another specific embodiment of the present invention, a first moving contact is disposed on the first moving contact, a first fixed contact is disposed on the first fixed contact, the first moving contact is contacted with or separated from the first fixed contact after the first moving contact swings, a second moving contact is disposed on the second moving contact, a second fixed contact is disposed on the second fixed contact, and the second moving contact is contacted with or separated from the second fixed contact after the second moving contact swings.

In a further specific embodiment of the present invention, the distance of the first movable contact from the swing center of the first movable contact is smaller than the distance of the second movable contact from the swing center of the second movable contact.

In a further specific embodiment of the present invention, when the first movable contact and the second movable contact are in the open position, the opening distance between the first movable contact and the first fixed contact is greater than the opening distance between the second movable contact and the second fixed contact.

In another specific embodiment of the present invention, the first movable contact piece and the second movable contact piece have the same shape and structure.

In a further specific embodiment of the present invention, the number of the second movable contact pieces is smaller than the number of the first movable contact pieces.

In a further specific embodiment of the present invention, the housing is formed by splicing a bottom plate and a base.

In a more specific embodiment of the present invention, the first movable contact and the second movable contact are arranged on the base in a swinging manner, and the first stationary contact and the second stationary contact are mounted on the bottom plate.

Compared with the prior art, the hybrid circuit breaker has the advantages that: the solid-state direct current circuit breaker and the mechanical circuit breaker can be used at the same time, and the contact is small in abrasion, long in electric service life, simple in structure and easy to realize.

Drawings

Fig. 1 is a schematic view of the overall structure of the circuit breaker according to the present invention.

Fig. 2 is a schematic diagram of an internal wiring method of the circuit breaker according to an embodiment of the present invention.

Fig. 3 is a schematic structural view of a first mechanical breaking device and a second mechanical breaking device according to the present invention.

Fig. 4 is a schematic diagram of the engagement of the moving contact and the stationary contact of the first mechanical disconnecting device according to the present invention.

Fig. 5 is a schematic diagram of the engagement of the moving and stationary contacts of the second mechanical disconnecting apparatus according to the present invention.

Fig. 6 is a schematic circuit diagram of the circuit breaker of the present invention.

In the figure: 1. the mechanical breaker comprises a first mechanical breaking device, 11, a first moving contact, 111, a first moving contact piece, 1111, a first moving contact, 12, a first fixed contact and 121, a first fixed contact; 2. the second mechanical breaking device, 21, a second moving contact, 211, a second moving contact piece, 2111, a second moving contact, 22, a second fixed contact and 221, a second fixed contact; 3. a power electronic switch; 4. a base plate; 51. a first outlet row, 52, a second outlet row; 6. a base; 7. an operating mechanism; 100. a first lapping bus bar; 200. a second lapping bus bar; 300. and a third lapping busbar.

Detailed Description

The following detailed description of the embodiments of the present invention will be described with reference to the accompanying drawings, but the description of the embodiments is not intended to limit the technical solutions, and any changes in form and not essential to the inventive concept should be regarded as the protection scope of the present invention.

In the following description, any concept related to the directionality (or the directional nature) of up, down, left, right, front, and rear is intended to facilitate understanding by the public, and thus should not be construed as particularly limiting the technical solution provided by the present invention, with respect to the position state in which the drawings are being described.

Referring to fig. 1 and 2, the present invention relates to a circuit breaker, and more particularly, to a hybrid circuit breaker. The circuit breaker comprises a shell, wherein the shell is formed by splicing a bottom plate 4 and a base 6, and at least three accommodating cavities which are spaced from each other are formed in the shell. The casing install operating device 7 in the outside of base 6, the internally mounted of casing has first mechanical cut-off device 1, second mechanical cut-off device 2 and power electronic switch 3, first mechanical cut-off device 1, second mechanical cut-off device 2 and power electronic switch 3 set up side by side and hold to one respectively and hold the intracavity. The mode can be used for the existing breaker shell, and the installation requirements of the three can be met only by a little change. The power electronic switch 3 can be arranged between the first mechanical breaking device 1 and the second mechanical breaking device 2; it can also be placed on one side of the first mechanical breaking device 1 and the second mechanical breaking device 2, i.e. the first mechanical breaking device 1 and the second mechanical breaking device 2 are placed adjacent to each other. In the present embodiment, only the mode between the first mechanical breaking device 1 and the second mechanical breaking device 2 is illustrated, and the first mechanical breaking device 1 and the second mechanical breaking device 2 are respectively located on two sides of the housing, but the protection scope is not limited thereto. The operating mechanism 7 drives the first mechanical breaking device 1 and the second mechanical breaking device 2 to act. The second mechanical breaking device 2 is connected in series with the power electronic switch 3, and the formed series circuit is connected in parallel with the first mechanical breaking device 1, so that two parallel current circulation paths are formed in the circuit breaker, wherein one is the first mechanical breaking device 1, and the other is the second mechanical breaking device 2 and the power electronic switch 3.

Further, the first mechanical breaking device 1 is a fracture which is mechanically opened and closed, the second mechanical breaking device 2 is another fracture which is mechanically opened and closed, and the power electronic switch 3 is a fracture which is mechanically opened and closed. In this embodiment, the first mechanical breaking device 1 and the second mechanical breaking device 2 both refer to a contact system that is mechanically turned on and off, and the power electronic switch 3 refers to an electronic device that is turned on and off by an IGBT, an IGCT, or the like.

Referring to fig. 3 in conjunction with fig. 1 and 2, the first mechanical breaking device 1 includes a first movable contact 11 and a first stationary contact 12, and similarly, the second mechanical breaking device 2 includes a second movable contact 21 and a second stationary contact 22. The first movable contact 11 and the first fixed contact 12 are correspondingly matched, and the second movable contact 21 and the second fixed contact 22 are correspondingly matched, where the corresponding matching mentioned herein means that the movable contact is contacted with or separated from the fixed contact after swinging.

The first moving contact 11 is arranged on the base 6 in a swinging manner, the first fixed contact 12 is arranged on the bottom plate 4, a first outlet line row 51 is respectively arranged on the outer side of the bottom plate 4 and corresponding to the first moving contact 11 and the first fixed contact 12, wherein the first outlet line row 51 of the first fixed contact 12 is positioned above the first outlet line row 51 of the first moving contact 11. The first moving contact 11 and the first fixed contact 12 are electrically connected to a first outlet line 51 respectively to realize the wiring of the first mechanical disconnecting link 1, and when the circuit breaker is connected to the power grid, the first mechanical disconnecting link 1 alone forms a current loop.

Similarly, the second movable contact 21 is arranged on the base 6 in a swinging manner, the second fixed contact 22 is mounted on the bottom plate 4, and second outlet lines 52 are respectively arranged outside the bottom plate 4 and corresponding to the second movable contact 21 and the second fixed contact 22. Here, the second outgoing line row 52 of the second movable contact 21 is as high as the first outgoing line row 51 of the first movable contact 11, and the second outgoing line row 52 of the second stationary contact 22 is as high as the first outgoing line row 51 of the first stationary contact 12. In order to form a series connection between the power electronic switch 3 and the second mechanical disconnecting device 2, a first overlapping busbar 100 is further arranged on the outer side of the bottom plate 4, and a second overlapping busbar 200 and a third overlapping busbar 300 are arranged inside the bottom plate 4. The first overlapping busbar 100 is L-shaped, and is used for connecting the second outlet line 52, corresponding to the second movable contact 21, below the bottom plate 4 to one end of the power electronic switch 3. Specifically, one end of the lower side of the first bridging busbar 100 is connected to the second outgoing line bar 52 of the second movable contact 21, one end of the upper side of the first bridging busbar 100 is connected to one end of the second bridging busbar 200, the other end of the second bridging busbar 200 is connected to one end of the power electronic switch 3, the other end of the power electronic switch 3 is connected to one end of the third bridging bar 300, the other end of the third bridging bar 300 is connected to the second movable contact 21, the second fixed contact 22 is connected to the second outgoing line bar 52, which is located above the bottom plate 4 and corresponds to the second mechanical breaking device 2, and the second movable contact 21 and the second fixed contact 22 are respectively connected to the corresponding second outgoing line bar 52, so far, the formation of the second current loop is completed.

When the circuit breaker is connected to a power grid, the outlet rows of the two current circuits need to be short-circuited to complete the parallel connection of the two circuits. Specifically, the first outlet line row 51 of the first movable contact 11 and the second outlet line row 52 of the second movable contact 21 which are located at the same height below the base 4, and the first outlet line row 51 of the first fixed contact 12 and the second outlet line row 52 of the second fixed contact 22 which are located at the same height above the base 4 are overlapped through the busbar, that is, the parallel connection of the two circuits is completed. Preferably, the overlap joint is realized by adopting a wiring bar in the cabinet. The row format mentioned here is only a specific example and should not be taken as a limitation of the scope of protection. For example, when the power electronic switch 3 is located on one side of the circuit breaker, the first mechanical disconnecting device 1 is located on the other side of the circuit breaker, and the second mechanical disconnecting device 2 is located between the first mechanical disconnecting device 1 and the power electronic switch 3, the first overlapping row 100 should be adjusted adaptively, and only the first overlapping row 100 needs to be installed by reversing, and at this time, the upper and lower second outgoing line rows 52 correspondingly connected to the second mechanical disconnecting device 2 and the power electronic switch 3 should be located at the same position.

With regard to the above solution, it should be further noted that, when the power electronic switch 3 is located at the middle phase position, that is, between the first mechanical breaking device 1 and the second mechanical breaking device 2, if the operating mechanism 7 of the circuit breaker is installed outside the middle phase, the first mechanical breaking device 1 and the second mechanical breaking device 2 may be symmetrically arranged on two sides of the operating mechanism 7, and when the two are located in a symmetric environment, the main shaft of the circuit breaker is not subjected to a biasing force; when the power electronic switch 3 is located on the side of the circuit breaker, the overlapping length of the external terminal block can be reduced because the first outlet line block 51 and the second outlet line block 52 on the same level of the two current loops are close to each other.

Further, at least one of the first, second, and third strap banks 100, 200, and 300 may be replaced with a shunt, so that the current of the circuit can be detected. The first overlapping row 100 may be referred to as a first electrical connector; the second overlapping row 200 can be a second electric connector; the third landing row 300 may be referred to as a third electrical connector.

In this hybrid circuit breaker, the structure or means for switching the current, i.e. when a fault current is generated in the circuit, is described below, i.e. the circuit breaker is to divert the current from the first current circuit of the first mechanical breaking device 1 into the second current circuit, which is formed by the second mechanical breaking device 2 in series with the power electronic switch 3, and to break the current through the power electronic switch 3. When the circuit breaker has been closed, the current to the second mechanical breaking device 2 is switched off by the power electronic switch 3, so that in the on-state situation the current flows only through the first mechanical breaking device 1.

Referring to fig. 3, the first movable contact 11 is provided with a first movable contact 1111 on the first movable contact 111, and correspondingly, a first stationary contact 121 is provided on the first stationary contact 12. The first movable contact 1111 cooperates with the first stationary contact 121, and when the first movable contact 1111 and the first stationary contact 121 are in contact with each other, the first mechanical opening/closing device 1 is in a closed state, and when the first mechanical opening/closing device 1 and the first stationary contact are separated from each other, the first mechanical opening/closing device 1 is in an open state. Similarly, the second moving contact 21 is provided with a second moving contact 2111 on the second moving contact piece 211, and correspondingly, a second fixed contact 221 is provided on the second fixed contact 22. The second movable contact 2111 cooperates with the second stationary contact 221, and when the two are in contact, the second mechanical disconnecting device 2 is in a closed state, and when the two are separated, the second mechanical disconnecting device 2 is in an open state.

Further, the circuit breaker may further include an arc extinguishing chamber (not shown). Specifically, an arc extinguishing chamber is arranged above the first mechanical breaking device 1, preferably, an arc extinguishing chamber is also arranged above the second mechanical breaking device 2, and a ventilation device is arranged above the power electronic switch 3, wherein the ventilation device enables heat on the power electronic switch 3 to be discharged outwards.

In terms of the technical scope of the present invention, the first movable contact 11 and the second movable contact 21 both rotate synchronously and are both driven by the main shaft of the circuit breaker. In order to allow the presence between said first mechanical breaking device 1 and said second mechanical breaking device 2: the design requirement of the first mechanical breaking device 1 breaking first and the second mechanical breaking device 2 breaking later in disjunction is that the rotation centers of the first movable contact 11 and the second movable contact 21 are both positioned on the same axis O, so the swing radius of the second movable contact 2111 is larger than that of the first movable contact 1111, and therefore, when the circuit breaker performs a breaking action, the separation between the second movable contact 2111 and the second fixed contact 221 is later than that between the first movable contact 1111 and the first movable contact 121, and the design requirement is met.

With reference to fig. 4 and 5, another solution is illustrated that enables the second mechanical breaking device 2 to break later than the first mechanical breaking device 1. In this technical solution, the first movable contact 11 and the second movable contact 21 have the same structure, that is, the same movable contact is adopted, and the first fixed contact 12 and the second fixed contact 22 have the same structure, only the distance between the movable contact and the fixed contact is adjusted.

Specifically, in the first mechanical opening/closing device 1, the opening moment between the first movable contact 1111 and the first fixed contact 121 is set to L1, and in the second mechanical opening/closing device 2, the opening distance between the second movable contact 2111 and the second fixed contact 221 is set to L2. By adjusting the installation positions of the first stationary contact 121 and the second stationary contact 221, L1 is made larger than L2. Naturally, after the above adjustment, the contact springs of the first movable contact 11 and the second movable contact 21 should be adjusted accordingly to meet the requirement for the contact pressure.

For the above two embodiments, the first movable contact 11 includes a first contact support, the first movable contact 111 is mounted on the first contact support, and a contact spring is disposed between the first movable contact 111 and the first contact support. When the first movable contact 111 contacts the first fixed contact 12, the first movable contact 11 continues to rotate, and at this time, the contact spring is compressed, which is called over travel.

Similarly, for the second movable contact 21, the second movable contact 21 includes a second contact support, the second movable contact 211 is mounted on the second contact support, and a contact spring is disposed between the second movable contact 211 and the second contact support. When the second movable contact piece 211 contacts the second fixed contact 22, the second movable contact 21 continues to rotate, and at this time, the contact spring is compressed, and this stroke is called over travel.

Referring to fig. 6, a circuit block diagram of the present embodiment is shown. When the circuit breaker encounters fault current, the controller or other triggering devices trigger the power electronic switch 3 to be switched on first, and when the circuit breaker is switched off, the first mechanical breaking device 1 is switched off first, at the moment, because the second mechanical breaking device 2 is not switched off yet, the current flows to the second mechanical breaking device 2, and then the controller or other triggering devices trigger the power electronic switch 3 to be switched off, so that the current is extinguished. The second mechanical breaking device 2 is then disconnected. When the circuit breaker performs a closing action, the controller or other triggering devices trigger the power electronic switch 3 to be switched on, then the second mechanical breaking device 2 is closed before the first mechanical breaking device 1, and when the first mechanical breaking device 1 enters a closing state, the controller or other triggering devices trigger the power electronic switch 3 to be switched off, so that in the switching-on state, current only flows through the first mechanical breaking device 1.

For the first movable contact 11 and the second movable contact 21, as the first mechanical breaking device 1 and the second mechanical breaking device 2 do not need to extinguish arcs, and the current is cut off and switched on by the power electronic switch 3, the contact loss is reduced, and the electric service life is prolonged.

In all the drawings in this patent, it is clearly understood that the specific embodiments are directed to a conventional circuit breaker or a frame circuit breaker, but in practice, the core structure of the molded case circuit breaker can be implemented as well, and therefore, the protection scope should cover the molded case circuit breaker.

Claims (9)

1. A circuit breaker comprises a shell, wherein a first mechanical breaking device (1), a second mechanical breaking device (2), a power electronic switch (3) and an operating mechanism (7) are installed in the shell, the operating mechanism (7) drives the first mechanical breaking device (1) and the second mechanical breaking device (2) to act, a series loop formed by connecting the second mechanical breaking device (2) and the power electronic switch (3) in series is connected with the first mechanical breaking device (1) in parallel, the first mechanical breaking device (1) comprises a first movable contact (11) and a first fixed contact (12) matched with the first movable contact (11), the second mechanical breaking device (2) comprises a second movable contact (21) and a second fixed contact (22) matched with the second movable contact (21), the first movable contact (11) comprises a first movable contact (111), the second moving contact (21) comprises a second moving contact piece (211), and is characterized in that: when the first moving contact (11) and the second moving contact (21) are in the opening position, the first moving contact (111) and the second moving contact (211) are in the same opening angle, and in the opening process, the separation of the second moving contact (21) and the second fixed contact (22) is later than that of the first moving contact (11) and the first fixed contact (12).

2. A circuit breaker according to claim 1 wherein said first movable contact (111) and said second movable contact (211) have an angular difference when said first movable contact (11) and said second movable contact (21) are in a closed position.

3. The circuit breaker according to claim 1, wherein the first moving contact (1111) is disposed on the first moving contact (111), the first stationary contact (12) is disposed with a first stationary contact (121), the first moving contact (1111) is in contact with or separated from the first stationary contact (121) after the first moving contact (11) swings, the second moving contact (2111) is disposed on the second moving contact (211), the second stationary contact (22) is disposed with a second stationary contact (221), and the second moving contact (2111) is in contact with or separated from the second stationary contact (221) after the second moving contact (21) swings.

4. A circuit breaker according to claim 3, characterized in that said first movable contact (1111) is at a smaller distance from the centre of oscillation of the first movable contact (11) than said second movable contact (2111) is at a distance from the centre of oscillation of the second movable contact (21).

5. A circuit breaker as claimed in claim 3, characterized in that when said first movable contact (11) and said second movable contact (21) are in the open position, the opening between the first movable contact (1111) and said first fixed contact (121) is greater than the opening between the second movable contact (2111) and said second fixed contact (221).

6. A circuit breaker according to claim 1 wherein said first movable contact (111) and said second movable contact (211) are identical in shape and configuration.

7. A circuit breaker according to claim 1 wherein the number of said second movable contacts (211) is less than the number of said first movable contacts (111).

8. A circuit breaker as claimed in claim 1 wherein said housing is formed by a base plate (4) and a base (6) which are joined together.

9. A circuit breaker as claimed in claim 8, characterized in that said first movable contact (11) and said second movable contact (21) are arranged on said base (6) in a swinging manner, and said first stationary contact (12) and said second stationary contact (22) are mounted on said base plate (4).

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