A dual magnetic circuit high current release for a circuit breaker

Abstract

The application discloses a double-magnetic-circuit large-current release of a circuit breaker, which comprises a magnetic conducting frame, an armature, a short circuit ring, a fixed plate, a compression spring and a guide rod. The middle part of the magnetic conducting frame is provided with a first rectangular opening for allowing a current-carrying copper bar of the circuit breaker to pass through, the upper part of the magnetic conducting frame is provided with an inverted triangular opening for arranging the armature, the upper part of the inverted triangular opening is provided with a second rectangular opening for dividing the magnetic circuit; the armature is in an inverted triangular shape and is composed of three parts, i.e., an upper armature, a lower armature and a non-magnetic body; the non-magnetic body is arranged in the middle part of the armature, and the upper armature, the lower armature and the non-magnetic body are fixedly connected with each other; the magnetic conducting frame, the lower armature and the working air gap between the magnetic conducting frame and the lower armature form a first magnetic circuit, the magnetic conducting frame, the upper armature and the working air gap between the magnetic conducting frame and the upper armature form a second magnetic circuit, the working air gap of the second magnetic circuit is smaller than that of the first magnetic circuit, and the magnetic flux area of the second magnetic circuit is smaller than that of the first magnetic circuit.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of switchgear, in particular to a double magnetic circuit large current release of circuit breaker. BACKGROUND

[0002] In the rail transit power supply system, the large current release of the current DC circuit breaker mostly adopts single magnetic circuit structure. In the actual application process, the single magnetic circuit large current release has some defects: 1) with the capacity of modern DC power supply system becoming larger and larger, the rated current and short circuit current peak of the system loop also become larger and larger, which requires the upper limit of the setting value of the large current release protection of the circuit breaker to increase. But for the single magnetic circuit large current release, the increase of the upper limit of the setting value increases the electromagnetic force received by the armature, which requires the use of a larger stiffness spring. Due to the compact structure of the large current release, the movement stroke of the armature is limited, in order to increase the setting current capacity of the circuit breaker, a disc spring set is used to meet the stiffness requirement, but the disc spring set has unstable reverse force characteristics due to its variable stiffness characteristics, size dispersion and lubrication maintenance problems, and the excessive stiffness increases the release response time of the circuit breaker; 2) there is a situation that when the loop current fluctuates up and down in the vicinity of the release current, the armature of the single magnetic circuit large current release will appear the phenomenon of shaking and attraction stagnation, which leads to the false release or no release of the circuit breaker. SUMMARY

[0003] In order to solve the problems in the background art, the purpose of the present application is to provide a double magnetic circuit large current release of circuit breaker.

[0004] In order to achieve the above purpose, the technical scheme adopted by the present application is:

[0005] A double magnetic circuit large current release of circuit breaker, comprising a magnetic conducting frame, an armature and a striking rod;

[0006] The middle part of the magnetic conducting frame is provided with a first rectangular opening for the current-carrying copper bar of the circuit breaker to pass through, and the upper part is provided with an inverted triangular opening for setting the armature, and the upper part of the inverted triangular opening is provided with a second rectangular opening for dividing the magnetic circuit;

[0007] The armature is in the shape of an inverted triangle and is composed of three parts: an upper armature, a lower armature and a non-magnetic body; the non-magnetic body is arranged in the middle part of the armature; the upper armature, the lower armature and the non-magnetic body are fixedly connected;

[0008] The magnetic conducting frame, the lower armature and the working air gap therebetween form a first magnetic circuit, the magnetic conducting frame, the upper armature and the working air gap therebetween form a second magnetic circuit, the working air gap of the second magnetic circuit is smaller than that of the first magnetic circuit, and the magnetic flux area of the second magnetic circuit is smaller than that of the first magnetic circuit.

[0009] The armature is fixedly connected with the impact rod, and when the armature moves, the impact rod is driven to move, the impact rod impacts the interlocking structure, and the tripping of the circuit breaker is realized.

[0010] In some embodiments, two short-circuit rings are symmetrically arranged on the second magnetic circuit formed by the magnetic conductive frame, the upper armature and the working air gap therebetween.

[0011] In some embodiments, a positioning bent plate is further included, the positioning bent plate is fixed on the magnetic conductive frame, a positioning hole is formed in the positioning bent plate, and the impact rod passes through the positioning hole.

[0012] In some embodiments, a stop sleeve, a fixed plate, a compression spring and a guide rod are further included.

[0013] A circular hole is arranged in the middle of the armature for the guide rod to pass through.

[0014] The fixed plate is fixedly installed on the top of the magnetic conductive frame, and the stop sleeve is arranged at the top end of the armature, and the fixed plate and the stop sleeve are used for limiting the armature.

[0015] The guide rod is connected with the fixed plate in an interference fit.

[0016] The compression spring is sleeved on the guide rod, and the upper end is limited by the armature.

[0017] In some embodiments, a setting scale adjusting device is further included, the setting scale adjusting device can adjust the compression amount of the compression spring, and is used for adjusting the setting current tripping value of the circuit breaker.

[0018] Compared with the prior art, the circuit breaker double-magnetic-circuit large-current tripping device has the following beneficial effects:

[0019] 1) The circuit breaker double-magnetic-circuit large-current tripping device provided by the present application adopts a double-magnetic-circuit structure, so that the upper limit of the tripping current of the large-current tripping device is greatly increased without changing the spring stiffness, and the circuit breaker can be used for short-circuit protection of a larger capacity.

[0020] 2) When the loop current fluctuates up and down in the vicinity of the tripping current, the armature of the tripping device is prevented from shaking and being attracted and stopped, so that the circuit breaker is prevented from being mis-tripped or not tripped. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 FIG. 1 is a schematic view of a circuit breaker double-magnetic-circuit large-current tripping device provided by the present application;

[0022] Figure 2 FIG. 2 is a structural schematic view of a magnetic conductive frame and a short-circuit ring of the double-magnetic-circuit large-current tripping device.

[0023] Figure 3 For Figure 1 the schematic diagram of two magnetic circuits and working air gap of the double magnetic circuit high current release of circuit breaker in

[0024] Figure 4 For Figure 1 the lateral partial sectional view schematic diagram

[0025] Figure 5 For the partial sectional view schematic diagram of the release principle of double magnetic circuit high current release

[0026] BRIEF DESCRIPTION OF DRAWINGS

[0027] 1, magnetic conductive frame; 2, armature; 3, stop sleeve; 4, short circuit ring; 5, fixed plate; 6, compression spring; 7, setting scale adjusting device; 8, impact lever; 9, guide bent plate; 10, guide lever; 21, upper armature; 22, non-magnetic body; 23, lower armature. DETAILED DESCRIPTION

[0028] In order to make the technical means, creative features, purposes and effects of the present application easy to understand, the following will further describe how the present application is implemented in combination with the drawings and specific embodiments.

[0029] As Figure 1 , Figure 2 and Figure 3 shown, the present application provides a double magnetic circuit high current release of circuit breaker, comprising a magnetic conductive frame 1, an armature 2 and an impact lever 8; the middle part of the magnetic conductive frame 1 is provided with a first rectangular opening for the current-carrying copper bar of the circuit breaker to pass through, the upper part is provided with an inverted triangular opening for setting the armature 2, the upper part of the inverted triangular opening is provided with a second rectangular opening for dividing the magnetic circuit; the armature 2 is in the shape of an inverted triangle and consists of three parts: an upper armature 21, a lower armature 23 and a non-magnetic body 22; the non-magnetic body 22 is arranged in the middle part of the armature 2; the upper armature 21, the lower armature 23 and the non-magnetic body 22 are fixedly connected.

[0030] The magnetic conductive frame 1, the lower armature 23 and the working air gap δ1 therebetween form a first magnetic circuit, the magnetic conductive frame 1, the upper armature 21 and the working air gap δ2 therebetween form a second magnetic circuit, the working air gap δ2 of the second magnetic circuit is smaller than that of the first magnetic circuit, and the magnetic flux area of the second magnetic circuit is smaller than that of the first magnetic circuit.

[0031] The armature 2 is fixedly connected with the impact lever 8, when the armature 2 moves, the impact lever 8 is driven to move, the impact lever 8 impacts the interlocking structure to realize the release and opening of the circuit breaker.

[0032] Further, the magnetic conductive frame 1 is symmetrically provided with two short circuit rings 4 on the second magnetic circuit formed by the upper armature 21 and the working air gap therebetween.

[0033] The tripping device further comprises a positioning bent plate 9 fixed on the magnetic conductive frame 1, the positioning bent plate 9 is provided with a positioning hole, and the impact rod 9 passes through the positioning hole.

[0034] The tripping device further comprises a stop sleeve 3, a fixed plate 5, a compression spring 6 and a guide rod 10; the armature 2 is provided with a circular hole in the middle for the guide rod 10 to pass through; the fixed plate 5 is fixedly installed on the top of the magnetic conductive frame 1, and the stop sleeve 3 is arranged at the top end of the armature 2; the fixed plate 5 and the stop sleeve 3 are used for limiting the armature 2; the guide rod 10 is connected with the fixed plate 5 in interference fit; and the compression spring 6 is sleeved on the guide rod 10, and the upper end is limited by the armature 2.

[0035] The tripping device further comprises a setting scale adjusting device 7, which can adjust the compression amount of the compression spring 6, and is used for adjusting the setting current tripping value of the circuit breaker.

[0036] The working principle is as follows: the first magnetic circuit generates a downward electromagnetic force F1 on the armature 2, and the second magnetic circuit generates an upward electromagnetic force F2 on the armature 2, so that the electromagnetic force acting on the armature 2 is During the stable rising process of the circuit breaker circuit current, at the initial time, since δ2 < δ1, F2 > F1, the armature 2 is subjected to an upward electromagnetic force. Since the upper end limits the armature 2, the armature 2 remains stationary. When the current rises to a certain value, the magnetic flux of the second magnetic circuit tends to be saturated, and F2 no longer increases. With the further increase of the current, the downward electromagnetic force F1 generated by the first magnetic circuit on the armature 2 further increases, and finally the armature 2 overcomes the resistance of the spring 6 to attract downward to realize the tripping of the circuit breaker. Due to the existence of the second magnetic circuit, the upper limit of the tripping current of the large current tripping device is greatly increased without changing the stiffness of the spring 6, and the circuit breaker can be used for larger capacity short circuit protection.

[0037] When the loop current is fluctuated up and down by external disturbance, a magnetic field varying with the current fluctuation is generated in the magnetic circuit formed by the magnetic conductive frame 1, the armature 2 and the working air gap, and the electromagnetic force received by the armature 2 also varies. Under the critical condition, if the electromagnetic force received by the armature 2 fluctuates around the resistance value of the spring 6, the resultant force of the electromagnetic force and the spring force received by the armature 2 will appear zero-crossing, at this time, the armature will appear up and down jitter phenomenon, if the jitter amplitude is too large, the circuit breaker will appear mis-trip phenomenon. Preferably, to solve this problem, two short-circuit rings 4 are symmetrically arranged on the magnetic conductive frame 1 located in the second magnetic circuit, when the magnetic field varies with the current fluctuation, induced eddy current is generated in the short-circuit ring 4, which hinders the change of the magnetic flux passing through the second magnetic circuit, and the electromagnetic force received by the armature 2 also lags behind the change of the magnetic flux, so that the electromagnetic attraction of the armature 2 is compensated, in this case, the electromagnetic force received by the armature 2 is always smaller than the resistance of the spring 6, so that the jitter of the armature 2 is reduced, and the mis-trip action of the circuit breaker caused by disturbance is avoided.

[0038] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present application but not limit the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the purpose and scope of the present application, and all of them should be covered in the scope of the claims of the present application.

Claims

1. A dual magnetic circuit high current release for a circuit breaker, characterized by, It comprises a magnetic conductive frame (1), an armature (2) and a striking rod (8); The middle part of the magnetic conductive frame (1) is provided with a first rectangular opening for the copper bar of the circuit breaker to pass through, the upper part is provided with an inverted triangular opening for the armature (2) to be arranged, the upper part of the inverted triangular opening is provided with a second rectangular opening for the magnetic circuit to be segmented; The armature (2) is in an inverted triangular shape and is composed of three parts: an upper armature (21), a lower armature (23) and a non-magnetic body (22); the non-magnetic body (22) is arranged in the middle part of the armature (2); the upper armature (21), the lower armature (23) and the non-magnetic body (22) are fixedly connected with each other; The magnetic conductive frame (1), the lower armature (23) and the working air gap therebetween form a first magnetic circuit, the magnetic conductive frame (1), the upper armature (21) and the working air gap therebetween form a second magnetic circuit, the working air gap of the second magnetic circuit is smaller than that of the first magnetic circuit, and the magnetic flux area of the second magnetic circuit is smaller than that of the first magnetic circuit; The armature (2) is fixedly connected with the striking rod (8), when the armature (2) moves, the striking rod (8) is driven to move, the striking rod (8) strikes the interlocking structure to realize the tripping and opening of the circuit breaker.

2. The dual magnetic circuit high current release of a circuit breaker according to claim 1, characterized in that, Two short-circuit rings (4) are symmetrically arranged on the second magnetic circuit formed by the magnetic conductive frame (1) and the upper armature (21) and the working air gap therebetween.

3. The dual magnetic circuit high current release of a circuit breaker according to claim 1, characterized in that, It further comprises a positioning bent plate (9) fixed on the magnetic conductive frame (1), the positioning bent plate (9) is provided with a positioning hole, and the striking rod (9) passes through the positioning hole.

4. The dual magnetic circuit high current release of a circuit breaker according to claim 1, wherein, It further comprises a stop sleeve (3), a fixed plate (5), a compression spring (6) and a guide rod (10); The armature (2) is provided with a circular hole in the middle part for the guide rod (10) to pass through; The fixed plate (5) is fixedly installed on the top of the magnetic conductive frame (1), the stop sleeve (3) is arranged at the top end of the armature (2), and the fixed plate (5) and the stop sleeve (3) are used for limiting the armature (2); The guide rod (10) is connected with the fixed plate (5) in an interference fit; The compression spring (6) is sleeved on the guide rod (10), and the upper end is limited by the armature (2).

5. The dual magnetic circuit high current release of claim 4 wherein, It further comprises a setting scale adjusting device (7) capable of adjusting the compression amount of the compression spring (6) for adjusting the setting current tripping value of the circuit breaker.

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