JP3000735B2 - Gas circuit breaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an arc rotary type self-extinguishing type gas circuit breaker.

[0002]

2. Description of the Related Art In a self-extinguishing type gas circuit breaker, a pressure boosting chamber is provided in which the pressure is increased by an arc generated when an electric current is cut off, and gas ejected from the pressure boosting chamber is blown to the arc. The arc is extinguished.

[0003] This type of gas circuit breaker has excellent arc extinguishing performance when the breaking current is large and the arc energy is large. However, when the breaking current is small, the pressure in the boosting chamber is not sufficiently increased, so that sufficient gas quenching is not possible. Arc performance cannot be expected.

Therefore, an arc rotary extinguishing mechanism is provided in which an arc driving coil which is excited by an arc current is provided, and a magnetic flux generated from the coil is linked with the arc so that the arc is rotated at a high speed to extinguish the arc. A self-extinguishing type gas circuit breaker was also proposed. FIG. 3 shows a configuration of a main part of this type of gas circuit breaker. In FIG. 3, reference numeral 1 denotes a cylindrical boosting chamber constituent member made of a conductive or insulating material;
Is a main circuit conductor on the fixed contact side provided so as to airtightly close the opening at one end of the booster chamber component 1. The booster chamber component 1 and the main circuit conductor 2 constitute the booster chamber 3. . A bottom portion 1a of the boosting chamber constituent member 1 is tapered so that a diameter decreases toward the main circuit conductor 1, and a hole 1b is formed in a center portion of the bottom portion 1a.
The nozzle portion 3n for gas ejection is formed by the hole 1b. The main circuit conductor 2 is provided with a terminal portion 2a, and this terminal portion is connected to an external terminal.

In the boosting chamber 3, a support 4 connected to the main circuit conductor 2, a tulip-shaped fixed arc contact 5 supported on the support 4, and a coil support 6 on the support 4. A stationary element 9 composed of a supported arc driving coil 7 and an annular arc traveling plate 8 disposed at an end of the arc driving coil 7 is disposed. One end of the arc drive coil 7 is electrically connected to the main circuit conductor 2 through the coil support 6 and the support 4, and the other end is an arc traveling plate 8.
Is electrically connected to

Reference numeral 10 denotes a rod-shaped or tubular movable arc contact connected to an operation device via an insulating operation rod (not shown).
The movable arc contact is positioned between the injection position where the movable arc contact comes into contact with the fixed arc contact 5 through the nozzle portion 3n of the boosting chamber 3 and the boosting chamber 3.
, And is linearly driven between the fixed arc contact and a breaking position at which a predetermined insulating distance is provided between the fixed arc contact and the fixed arc contact. The movable arc contact 10 is connected to a main circuit conductor on the movable contact side via a not-shown current collecting contact. Each of the above parts is disposed in a circuit breaker container in which SF ₆ gas is sealed.

In the above-described circuit breaker, the movable arc contact 1
When 0 moves away from the fixed arc contact 5, an arc is generated between the two arc contacts. When the arc comes into contact with the arc traveling plate 8, an arc current flows through the arc driving coil 7, so that a magnetic flux is generated from the coil, and the magnetic flux links with the arc. The arc rotates at high speed along the arc traveling plate 8 by receiving a driving force by this magnetic flux. Further, the gas in the pressurizing chamber 3 is expanded by the energy of the arc, and the pressure in the pressurizing chamber 3 increases. Since the arc is rotating at a high speed, energy is efficiently supplied from the arc to the gas in the pressurizing chamber 3, and the pressure in the pressurizing chamber rapidly increases. Further, since the gas is relatively blown to the arc by the rotation of the arc, the arc is cooled.

When the movable arc contact comes out of the boosting chamber 3, gas in the boosting chamber is blown out from the nozzle portion 3n, and this gas is blown to the arc. Since the operation timing of the movable arc contact is set so that the time at which the gas is blown coincides with the zero point of the current, the arc is extinguished at the zero point of the current by blowing the gas from the boosting chamber 3.

When the breaking current is small, the arc energy is insufficient and the pressure in the boosting chamber does not rise sufficiently, so that the self-extinguishing effect by blowing the gas ejected from the boosting chamber cannot be expected much. In this case,
We hope that the arc will be extinguished by the cooling effect of the gas blown relatively to the arc by the high-speed rotation of the arc.

[0010]

In the gas circuit breaker described above, when the breaking current is large, high arc extinguishing performance is achieved by the cooling effect of the relative gas blowing generated by blowing the gas from the boosting chamber and the rotation of the arc. Obtainable. However, when the cutoff current is small, the current flowing through the arc drive coil is small and the rotational driving force of the arc is weak, and the pressure rise in the boosting chamber is also weak. As the arc extinguishing performance decreases and the arc time becomes longer, the arc becomes longer, so that the relative gas blowing effect due to the rotation of the arc becomes weaker.

It is an object of the present invention to provide an arc-rotating self-extinguishing type gas circuit breaker having improved arc extinguishing performance when a small current is interrupted.

[0012]

SUMMARY OF THE INVENTION The present invention provides a booster chamber having a nozzle for gas ejection, a fixed arc contact, and an arc drive provided to surround the fixed arc contact and excited by an arc current. A fixed side element disposed in a boosting chamber including a coil and an arc rotating plate disposed at an end of the arc driving coil, and a charging position and a boosting chamber that come into contact with a fixed arc contact through a nozzle portion of the boosting chamber. The present invention relates to a gas circuit breaker provided with a movable arc contact that is linearly driven between a breaking position and a breaking position at which a predetermined insulation distance is provided between the moving arc contact and the fixed arc contact.

In the present invention, an annular arc runner made of a non-magnetic material is arranged concentrically with the movable arc contact at a position away from the boosting chamber. A permanent magnet for rotating the arc is arranged inside the arcrunner, and a magnetic flux is generated from the magnet so as to intersect the arc at a right angle.

The non-magnetic material means a conductive metal material (eg, copper or the like) other than the ferromagnetic material.

[0015]

When the permanent magnet for driving the arc rotation is arranged outside the boosting chamber as described above, the arc time becomes longer when a small current is interrupted, and when the arc becomes longer, the magnetic flux generated from the permanent magnet is reduced. Since the arc is linked to the arc, the arc rotates at high speed while contacting the arc runner. Since gas is blown relatively to the arc by the rotation of the arc, stable arc extinguishing performance can be obtained even in a small current range.

With the above configuration, the arc comes into contact with the surface of the arc runner. However, the arc does not concentrate on a specific portion of the arc runner, but rotates at high speed along the circumferential direction of the arc runner. There is no unevenness that causes the electric field to be disturbed. Therefore, the arc runner can be provided with a function as a shield for shielding the permanent magnet from the fixed element.

[0017]

FIG. 1 shows an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a cylindrical boosting chamber forming member made of a conductive material, and 2 denotes an opening at one end of the boosting chamber forming member 1 in an airtight manner. The step-up chamber 3 is constituted by the step-up chamber constituent member 1 and the main circuit conductor 2 with the main circuit conductor on the side of the fixed contact to be closed. As in the conventional case, the bottom 1a of the booster chamber component 1
And a hole 1b is formed at the center thereof,
A nozzle portion 3n for gas ejection is formed by the bottom portion 1a and the hole 1b.

In the boosting chamber 3, a support 4, a fixed arc contact 5, a coil support 6, an arc driving coil 7
And a fixed-side element 9 comprising an annular arc traveling plate 8. The structure of the fixed side element is also the same as that of the conventional one. One end of the arc drive coil 7 is electrically connected to the main circuit conductor 2 through the coil support 6 and the support 4, and the other end is the arc traveling plate 8. Is electrically connected to

Reference numeral 10 denotes a movable arc contact similar to the conventional one. The movable arc contact is operated by an operating device (not shown) to make contact with the fixed arc contact 5 through the nozzle portion 3n of the boosting chamber 3; It is linearly driven between the chamber 3 and a breaking position at which a predetermined insulating distance is left between the chamber 3 and the fixed arc contact.

In the present invention, an annular cylinder 11 made of a good conductive material (eg, copper) other than a ferromagnetic material is disposed at a position separated from the boosting chamber 3 by a predetermined insulating distance. The illustrated cylindrical body 11 is formed in a cylindrical shape as a whole, and provided at an end on the side of the pressurizing chamber with an inner flange portion in which a portion closer to the inner circumference is bent inward. The arc runner 11a is constituted by the tip of the body. Arcranna 11
a, a circular concave portion 11b for holding a magnet is formed inside the concave portion 11a.
Are fixed by appropriate means. The magnet 12 is shown in FIG.
As shown in (1), in order to generate a magnetic flux orthogonal to the arc, the magnet is radially magnetized so that different magnetic poles appear on the inner and outer peripheral surfaces thereof. In the illustrated example, the magnet 12 is magnetized such that the inner peripheral surface is an N pole and the outer peripheral surface is an S pole. It is to be noted that the inner peripheral surface of the magnet 12 is the S pole and the outer peripheral surface is the N
It may be magnetized to be a pole.

The potential of the cylinder 11 is fixed to the potential of a main circuit conductor (not shown) which is electrically connected to the movable contact via a current collecting contact.

Each of the above-mentioned parts is housed in a cut-off part container (not shown), in which SF ₆ gas is sealed at a predetermined pressure.

In the above embodiment, when the circuit breaker is turned on, the movable arc contact 10 comes into contact with the fixed arc contact 5 from the inside through the nozzle 3n of the boosting chamber 3. In this state, the main circuit conductor 2 → the support 4 → the fixed arc contact 5 →
A main circuit current flows through a path from the movable arc contact 10 to a main circuit conductor (not shown).

When the movable arc contact 10 is separated from the fixed arc contact 5, an arc is generated between the two arc contacts. When this arc comes into contact with the arc traveling plate 8, the main circuit conductor 2 → the support 4 → the coil support 6 → the arc driving coil 7 → the arc traveling plate 8 → the arc → the movable arc contact 10
The arc current flows through the path, and the arc drive coil 7 is excited. Since the magnetic flux generated from the arc driving coil 7 is linked to the arc, the arc rotates at high speed along the arc traveling plate 8 and gas is blown relatively to the arc. As a result, the arc is cooled, the arc energy is efficiently given to the gas in the pressurizing chamber 3, and the pressure in the pressurizing chamber rapidly increases.

When the movable arc contact comes off the nozzle 3n, the gas in the booster chamber 3 is blown out from the nozzle 3n, and this gas is blown to the arc, so that the arc is extinguished at the zero current.

When the cutoff current is small, the pressure in the boosting chamber 3 is insufficient, and the arc extinguishing performance is reduced, so that the arc time becomes longer and the arc becomes longer. At this time, if the arc has reached the vicinity of the arc runner 11a, the magnetic flux generated from the arc rotation driving permanent magnet 12 links to the arc, so that the arc rotates at high speed in the circumferential direction along the surface of the arc runner 11a. Thereby, gas is blown relatively to the arc to cool the arc, and the arc is extinguished at the current zero point. Therefore, excellent arc extinguishing performance can be obtained even in a region where the breaking current value is small.

When the arc is driven to rotate by the magnetic flux generated from the permanent magnet, the arc comes into contact with the surface of the arc runner. In this case, the arc does not concentrate on a specific portion of the arc runner, but in the circumferential direction of the arc runner. Since it rotates at a high speed along the arc runner, there is no unevenness on the surface of the arc runner that may disturb the electric field. Therefore, the arc runner (cylinder 11) can have a function as a shield.

In the above example, only the fixed arc contact and the movable arc contact are provided. In addition to these contacts, a fixed main contact and a movable main contact are provided, and the movable arc contact is provided at the time of closing. The movable main contact comes in contact with the fixed main contact after the contact comes into contact with the fixed arc contact, and at the time of interruption, the movable arc contact comes off the fixed main contact after the movable main contact separates from the fixed main contact. Each contact may be arranged so as to be away from the contact, and the present invention can be applied to such a case.

In the above embodiment, a single ring-shaped magnet is used as the arc rotation driving permanent magnet 12, but a ring-shaped magnet may be formed by arranging a plurality of arc-shaped magnets. A large number of arc-shaped magnets may be arranged at intervals. Regardless of the arrangement of the magnets, it is necessary to magnetize the magnets so as to generate a magnetic flux intersecting at right angles with the arc.

[0030]

As described above, according to the present invention, the arc runner and the permanent magnet for driving the arc rotation are disposed outside the boosting chamber, and the magnetic flux generated from the permanent magnet when the arc becomes longer is provided. Since the arc is linked to the arc and driven to rotate, stable arc extinguishing performance can be obtained even in a small current range.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a main part of an embodiment of the present invention.

FIG. 2 is a perspective view of a permanent magnet used in the embodiment of FIG.

FIG. 3 is a longitudinal sectional view showing a structure of a main part of a conventional gas circuit breaker.

[Explanation of symbols]

3 ... Pressurizing chamber, 3n ... Nozzle part, 5 ... Fixed arc contact,
7 arc driving coil, 8 arc traveling plate, 9 fixed element, 10 movable arc contact, 11 cylinder, 1
1a: arc runner, 12: permanent magnet for arc rotation drive.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01H 33/18 H01H 33/70

Claims (1)

(57) [Claims] 1. A boosting chamber having a nozzle for gas ejection, a fixed arc contact, an arc driving coil provided to surround the fixed arc contact and excited by an arc current, and an end of the arc driving coil. A fixed-side element disposed in the pressurizing chamber including an arc rotating plate disposed in the pressure-inverting chamber; a charging position in contact with the fixed arc contact through a nozzle portion of the pressurizing chamber; A movable arc contact that is linearly driven between the arc contact and a breaking position at which a predetermined insulation distance is provided between the arc contact and the movable arc contact. An annular arc runner made of a nonmagnetic material concentrically arranged with the arc contact, and an arc arranged inside the arc runner to generate a magnetic flux intersecting at right angles to the arc Rolling gas circuit breaker characterized by comprising the driving permanent magnets.