Vacuum arc extinguishing chamber contact, vacuum arc extinguishing chamber and vacuum circuit breaker

Abstract

The invention relates to a vacuum arc extinguishing chamber contact, a vacuum arc extinguishing chamber and a vacuum circuit breaker. The contact includes a contact blade, a first contact cup and a second contact cup. The first contact cup is arranged in the second contact cup. One end of the first contact cup is connected with the second contact cup, and the other end of the first contact cup is connected with the contact blade. The contact blade is connected with the second contact cup. According to the invention, a single longitudinal magnetic field is split into a plurality of independent longitudinal magnetic field areas, a plurality of coils are used for shunting current, and the current density is reduced, thereby solving the contradiction between interrupting of the large short-circuit current and the temperature rise of the large rated current.

Claims

1. A vacuum arc extinguishing chamber contact, comprising a contact blade, a plurality of first contact cups and a second contact cup, wherein the first contact cups are arranged in the second contact cup and arranged in a circumferential array with respect to a geometric center of the second contact cup, and one end of each of the first contact cups is connected with the second contact cup, and the other end of each of the first contact cups is connected with the contact blade.

2. The vacuum arc extinguishing chamber contact according to claim 1, wherein the contact blade is connected with the second contact cup.

3. The vacuum arc extinguishing chamber contact according to claim 2, wherein an upper end surface of each of the first contact cups and an upper end surface of the second contact cup are in a same plane.

4. The vacuum arc extinguishing chamber contact according to claim 3, further comprising a plurality of magnetic collecting rings respectively arranged in the first contact cups.

5. The vacuum arc extinguishing chamber contact according to claim 4, further comprising a reinforcing rib arranged in the second contact cup.

6. The vacuum arc extinguishing chamber contact according to claim 5, wherein each of the first contact cups is cylindrical or horseshoe-shaped or other coil capable of forming a longitudinal magnetic field.

7. The vacuum arc extinguishing chamber contact according to claim 1, wherein a wall of the second contact cup is provided with a chute.

8. The vacuum arc extinguishing chamber contact according to claim 7, wherein a wall of each of the first contact cups is provided with a chute.

9. A vacuum arc extinguishing chamber comprising a first conductive rod, a second conductive rod, a first end cap, a second end cap, a grading ring of a first end, a grading ring of a second end, an insulating shell, a main shielding cover, a corrugated pipe and a shielding cover of the corrugated pipe, wherein the vacuum arc extinguishing chamber comprises two vacuum arc extinguishing chamber contacts as claimed in claim 1; the first conductive rod is connected with a first contact, and the second conductive rod is connected with a second contact; the first conductive rod is connected with the first end cap, the first end cap is connected with the first grading ring, and the first grading ring is connected with the insulating shell; the second conductive rod is connected with the shielding cover of the corrugated pipe, the shielding cover of the corrugated pipe is connected with one end of the corrugated pipe, and the other end of the corrugated pipe is connected with the second end cap, and the second end cap is connected with the grading ring of the second end; and the grading ring of the second end is connected with one end of the insulating shell.

10. The vacuum arc extinguishing chamber according to claim 9, further comprising a guide sleeve and a positioning ring of the guide sleeve, wherein the guide sleeve is arranged between the first conductive rod and the corrugated pipe, and the positioning ring of the guide sleeve is connected with the first end cap and presses against the guide sleeve.

11. A vacuum circuit breaker provided with the vacuum arc extinguishing chamber as claimed in claim 10.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure.

(2) FIG. 1 is an overall external schematic diagram of a vacuum arc extinguishing chamber contact of embodiments I-III of the present invention.

(3) FIG. 2 is an internal structure diagram of the vacuum arc extinguishing chamber contact in the embodiment II of the present invention.

(4) FIG. 3 is an axial sectional view of the vacuum arc extinguishing chamber of embodiment IV of the present invention.

DESCRIPTION OF THE EMBODIMENTS

(5) The present invention now will be described more clearly and fully hereinafter with reference to the accompanying drawings, in which it is apparent that the described embodiments are only a few, but not all embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without involving any inventive effort are within the scope of the present invention.

(6) Now, as mentioned in the background art, a product which realizes such a large current interrupting capacity and can conduct and carry a rated current of 6300 A for a long time has not yet appeared in the field. In the conventional theory, the diameter of a contact and the rotation angle of a coil arranged below a contact blade are increased to increase the magnetic field strength so as to meet the interrupting capacity of such a large short-circuit current. However, after the rotation angle of the coil is increased, it would be difficult to process, causing a main thing that the current path is obviously increased and the resistance of the contact becomes large. Therefore, the vacuum arc extinguishing chamber is difficult to conduct and carry a large rated current, and causes serious heating, which cannot meet the type test and normal operation requirements.

Embodiment I

(7) The vacuum arc extinguishing chamber contact of the embodiment is applied to a vacuum arc extinguishing chamber of vacuum circuit breaker at a generator outlet, and the design specification is as follows: rated voltage: 24 KV, rated current: 6300 A, and rated short-circuit interrupting current: 90 KA. The vacuum arc extinguishing chamber contact comprises one second contact cup 5, three first contact cups 4 and one contact blade 1. The three first contact cups 4 are all cylindrical and uniformly distributed on an inner bottom surface of the second contact cup 5, and a gap exists between two adjacent first contact cups 4. A wall of the second contact cup 5 is provided with three chutes. A wall of the first contact cup 4 is provided with three chutes. The chutes of the first contact cup 4 and the second contact cup 5 are arranged on the outer surface of the wall and do not penetrate through the wall. The chutes incline in an arc shape from bottom to top of the cup, and are uniformly distributed. The bottom of each first contact cup 4 is brazed with the inner bottom surface of the second contact cup 5, and an upper end surface of each first contact cup 4 and an upper end surface of the second contact cup 5 are positioned at the same height and brazed with the contact blade 1.

Embodiment II

(8) As shown in FIG. 1 and FIG. 2, the vacuum arc extinguishing chamber contact of the embodiment is applied to a vacuum arc extinguishing chamber of vacuum circuit breaker at a generator outlet, and the design specification is as follows: rated voltage: 24 KV, rated current: 6300 A, and rated short-circuit interrupting current: 90 KA. The vacuum arc extinguishing chamber contact comprises one second contact cup 5, six first contact cups 4, one contact blade 1, six magnetic collecting rings 3 and one reinforcing rib 2.

(9) The magnetic collecting ring 3 is made of electrical pure iron with high magnetic permeability, the second contact cup 5 is made of copper with high conductivity, and the reinforcing rib 2 is made of stainless steel.

(10) The magnetic collecting ring is annular, and deep grooves are uniformly distributed and axially formed in the annular ring.

(11) The six first contact cups 4 have annular cross sections and are uniformly distributed on the inner bottom surface of the second contact cup 5, and a gap exist between two adjacent first contact cups 4. The wall of the second contact cup 5 is provided with four chutes. The wall of each of the first contact cups 4 is provided with five chutes. The bottom of each first contact cup 4 is brazed with the inner bottom surface of the second contact cup 5, and the upper end surface of each first contact cup 4 and the upper end surface of the second contact cup 5 are positioned at the same height and brazed with the contact blade 1.

(12) The magnetic collecting rings 3 are arranged in the six first contact cups 4 so as to enhance the longitudinal magnetic field formed by each first contact cup 4. The reinforcing rib 2 is arranged at the center of the second contact cup 5 and plays a supporting role between the contact blade 1 and the reinforcing rib 2.

Embodiment III

(13) The vacuum arc extinguishing chamber contact of the embodiment is applied to a vacuum arc extinguishing chamber of vacuum circuit breaker at a generator outlet, and the design specification is as follows: rated voltage: 24 KV, rated current: 6300 A, and rated short-circuit interrupting current: 90 KA. The vacuum arc extinguishing chamber contact comprises one second contact cup 5, six first contact cups, one contact blade 1, six magnetic collecting rings and one reinforcing rib 2.

(14) The six first contact cups are all horseshoe-shaped assemblies capable of generating longitudinal magnetic fields and are uniformly arranged on the inner bottom surface of the second contact cup 5, and a gap exists between two adjacent first contact cups 4.

(15) The second contact cup 5 is made of a copper material with high conductivity, and four chutes are formed in the wall of the second contact cup 5. The wall of the first contact cup and the wall of the second contact cup 5 are also provided with four chutes. The bottom of each first contact cup is brazed with the inner bottom surface of the second contact cup 5, and the upper end surface of each first contact cup and the upper end surface of the second contact cup 5 should be positioned at the same height and brazed with the contact blade 1.

(16) The six first contact cups are internally provided with magnetic collecting rings. The magnetic collecting rings are annular, and the annular rings are axially provided with straight grooves which penetrate through the inside and the outside of the annular rings. In order to enhance the longitudinal magnetic field formed by each first contact cup, the magnetic collecting ring is made of electrical pure iron with high magnetic permeability.

(17) The reinforcing ribs 2 is arranged at the center of the second contact cup 5, is made of stainless steel and plays a supporting role between the contact blade 1 and the reinforcing rib 2.

Embodiment IV

(18) The vacuum arc extinguishing chamber shown in FIG. 3 comprises a first conductive rod 6, a second conductive rod 17, a first contact 13, a second contact 14, a first end cap 7, a second end cap 16, a grading ring 8 of a first end, a grading ring 15 of a second end, an insulating shell 11, a main shielding cover 12, a corrugated pipe 9, a shielding cover of the corrugated pipe 10, and a guide sleeve. The first contact 13 and the second contact 14 are identical, and the internal structure of the contact is the same as that of the embodiment 1, which will not be described in detail. The first conductive rod 6 is connected with the first contact 13, and the second conductive rod 17 is connected with the second contact 14. The first conductive rod 6 is brazed with the first end cap 7, the first end cap 7 is brazed with the grading ring 8 of the first end, the grading ring 8 of the first end is brazed with the insulating shell 11, the first conductive rod 6 is brazed with the shielding cover 10 of the corrugated pipe, the shielding cover 10 of the corrugated pipe is brazed with one end of the corrugated pipe 9, and the other end of the corrugated pipe 9 is brazed with the first end cap 7. The second end cap 16 is brazed with the grading ring 15 of the second end, and the grading ring 15 of the second end is brazed with one end of the insulating shell 11, thereby forming a closed vacuum space. The guide sleeve is arranged between the first conductive rod 6 and the corrugated pipe 9, and the positioning ring of the guide sleeve is welded with the first end cap 7 and presses against the guide sleeve.

(19) When the vacuum arc extinguishing chamber is normally operated in a closed state, the current can be introduced by the first conductive rod 6 and the second conductive rod 17, as described here in the first case. When the current flows to the second contact cup 5 of the first contact 13 from the first conductive rod 6, the current is distributed to the wall of the second contact cup 5 and the wall of each first contact cup 4, and then is converged to the contact blade 1 of the first contact. The current then flows through the contact blade 1 of the second contact 14 and is distributed to the wall of the second contact cup 5 and the wall of each first contact cup 4, and then is converged to the second conductive rod 17 and outflows to the conductive circuit in the circuit. The current at the moment is shunted by a plurality of contact cups, and the current density in each contact cup is low, so that the vacuum arc extinguishing chamber has low heat generation and long-term reliable safety operation.

(20) When a short circuit occurs in the line and the vacuum circuit breaker is switched off to separate the two contacts of the vacuum arc extinguishing chamber, an intensive arc is generated between the first contact 13 and the second contact 14. At the moment, the current is distributed into the walls of a plurality of contact cups, and the wall of each contact cup is provided with a plurality of chutes, so that the longitudinal current is changed to the current flowing along a winding path in the wall. Therefore, a strong longitudinal magnetic field can be generated in a space corresponding to each contact cup, the electric arcs of the contact gaps can be well controlled by the plurality of magnetic field areas and dispersed to the surfaces of the contact blades 1 in a plurality of magnetic field areas for burning, and the arcs are diffused, so that when the alternating current crosses zero, the insulation capacity can be quickly restored between fractures of the vacuum arc extinguishing chamber, and the large short-circuit current can be effectively extinguished.

(21) In this specification, various embodiments have been described in an incremental manner. Each embodiment is described with emphasis on differences from other embodiments, while the identical or similar parts of the embodiment are described with reference to one another. The above description of the disclosed embodiments is provided to enable those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.