JP2881841B2 - Gas circuit breaker - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a gas circuit breaker which uses both an arc-extinguishing type arc-extinguishing method and a self-expanding type arc-extinguishing method.

[Prior Art] As arc extinguishing methods of a gas circuit breaker, there are known an arc extinguishing method of an arc rotation type and an arc extinguishing method of a self-expansion type (auto-expansion type).

The arc-extinguishing method of the arc rotation type links the magnetic flux generated from the arc drive coil excited by the arc current with the arc, and rotates the arc at high speed in the arc-extinguishing gas to spray gas relatively to the arc. This is a method to extinguish the arc.

In addition, the self-expansion type arc extinguishing method provides a high-pressure gas by providing a booster chamber surrounding the arc generating space, and ejecting the gas in the booster chamber, whose pressure has increased due to self-expansion by the strong energy of the arc, from the insulating nozzle. A flow is generated, and the gas flow is blown against an arc to extinguish the arc.

6 and 7 show a conventional gas circuit breaker using both an arc-extinguishing method of an arc rotation type and a self-expansion type arc-extinguishing method. FIG. 6 shows a closed state, and FIG. Indicates a cutoff state.

In these figures, reference numeral 1 denotes a cylindrical boosting chamber forming cylinder,
Reference numeral 2 denotes a disc-shaped fixed contact-side conductor attached so as to close the upper end of the cylinder 1 secretly. Reference numeral 3 denotes an insulating plate attached so as to close the bottom of the cylinder 1 airtightly.
An insulating nozzle 4 is formed at the center of the. An external terminal (not shown) is connected to the fixed contact-side conductor 2. The step-up chamber 5 is constituted by the step-up chamber forming cylinder 2, the conductor 2 and the insulating plate 3.

An annular fixed contact 6 is connected to the center of the inner surface of the conductor 2, and an arc drive coil 7 is arranged so as to concentrically surround the fixed contact. Arc drive coil 7
Is electrically connected to the conductor 2 and the other end of the coil is electrically connected to an annular arc rotating electrode 8 coaxially arranged with the fixed contact.

Reference numeral 9 denotes a movable contact which moves into and out of the pressurizing chamber 5 through the nozzle 4, and the movable contact is, as shown in FIG.
As shown in the figure, it is displaced between a fixed position and a blocking position where it is separated from the nozzle 4 by a predetermined distance. The movable contact is electrically connected to a movable contact side conductor (not shown) provided at a fixed location via a current collector, and an external terminal is connected to the movable contact side conductor.

The main part of the cut-off part is composed of the above parts,
This shut-off section is housed in a circuit breaker container filled with SF ₆ gas.

When the circuit breaker is in the closed state shown in FIG. 6, a seed circuit current flows through the fixed contact-side conductor 2-fixed contact 6-movable contact 9-movable contact-side conductor (not shown).

When the movable contact 9 is moved downward in the drawing to separate from the fixed contact 6 in order to open the circuit breaker, an arc A1 is generated between both contacts. A current flows through the arc driving coil 7 from the moment the arc contacts the arc rotating electrode 8, and the coil is excited. Since the magnetic flux generated from this coil links with the arc A1, a rotational force is applied to the arc, and the arc A1 rotates at high speed along the arc rotating electrode 8. As a result, gas is blown relatively to the arc A1, and the arc is cooled.

Further, since the gas in the pressurizing chamber 5 expands rapidly due to the strong energy of the arc, the movable contact 9
The pressure in the pressurizing chamber 5 increases during the period of fitting.

When the movable contact 9 comes off from the nozzle 4, the gas in the pressurizing chamber 5 blows out through the nozzle 4, and a high-speed gas flow is generated. Since this gas flow is blown to the arc A2, the arc is further cooled and extinguished at the current zero point.

[Problems to be Solved by the Invention] During the period in which the movable contact 9 is fitted to the nozzle 4 in the process of shutting off the gas circuit breaker, the surrounding gas rotates with the high-speed rotation of the arc A1. Is moved radially outward by centrifugal force. The gas moved to the outside in the radial direction flows into the space Q outside the arc drive coil 7 and increases the pressure in the space Q. This space Q is closed at one end side (the conductor 2 side) in the axial direction. Since the gas moved by the centrifugal force from the arc A1 side flows into the space Q, the gas in the space Q is immediately discharged when the movable contact 9 is separated from the nozzle 4. 4 could not be drained. Therefore, it is difficult to intensify the gas blow to the arc immediately after the movable contact 9 is detached from the nozzle 4, and this is one of the factors that hinder the improvement of the breaking performance.

An object of the present invention is to improve the breaking performance by strengthening the blowing of gas to the arc when the movable contact is detached from the insulating nozzle and making the ionized gas and fresh gas stir well. It is an object of the present invention to provide a gas circuit breaker that can be designed.

[Means for Solving the Problems] A circuit breaker according to the present invention is, as shown in FIGS. 1 to 3 showing an embodiment thereof, a booster chamber 16 having an insulating nozzle 15.
A fixed contact 17 provided in the pressurized chamber with the axis shared with the insulating nozzle, and an arc coaxially arranged with the fixed contact in a gas space located between the fixed contact in the pressurized chamber and the insulating nozzle. A drive coil 20, and first and second arc rotating electrodes disposed coaxially with the arc drive coil and electrically connected to the fixed contact side end and the insulating nozzle side end of the arc drive coil, respectively. 23 and 24, and a movable contact 26 which is displaced between a closing position where the fixed contact is brought into contact with the fixed contact through a passage including the inside of the insulating nozzle and the inside of the arc driving coil, and a blocking position where the fixed contact is separated from the insulating nozzle. ing.

An insulating means 25 for insulating the movable contact from the arc rotating electrode can be provided inside the arc driving coil.

Also, as can be seen in FIGS. 4 and 5, a contact in which the movable contact slides on the second arc rotating electrode 24 '.
28 can also be connected. In this case, the movable contact 26
Is electrically connected to the second arc rotating electrode until it is separated from the second arc rotating electrode.

[Operation] In the above-described gas circuit breaker, when the movable contact moves away from the fixed contact, an arc is generated between the two contacts. When the tip of the movable contact moves further toward the second arc rotating electrode than the position of the first arc rotating electrode, the arc moves to the first arc rotating electrode. The gas in the pressurizing chamber is heated and expanded by the energy of the arc. At this time, since the movable contact is in a state of being fitted to the insulating nozzle and the pressurizing chamber is substantially sealed, the ionized gas near the arc flows as indicated by an arrow q in FIG. Agitated with fresh gas Q in 16,
It is pushed into the nozzle unit 15. As a result, the pressure in the pressurizing chamber rapidly increases. When the movable contact further moves and the tip of the movable contact reaches a position closer to the insulating nozzle than the second arc rotating electrode, an arc is also generated between the movable contact and the second arc rotating electrode. From this moment, a current flows through the arc driving coil, and the magnetic flux generated from the arc driving coil is linked to the arcs generated on the first arc rotating electrode side and the second arc rotating electrode side, respectively. As a result, the arcs rotate at high speed along the first arc rotating electrode and the second arc rotating electrode, respectively.

When the movable contact further moves to the blocking position side and separates from the insulating nozzle, gas in the boosting chamber blows out of the insulating nozzle at a stretch, and the gas is blown to the arc. The arc is cooled by both the relative gas blowing performed by the high-speed rotation and the gas blowing from the pressurized chamber through the insulating nozzle, and disappears at the current zero point.

When the arc drive coil is arranged in the space between the fixed contact and the insulating nozzle as described above, the space outside the arc drive coil becomes a space opened to both sides in the axial direction in the boosting chamber, so that the movable contact is insulated. At the moment when the gas comes off from the nozzle, the gas in each part in the boosting chamber is smoothly guided to the insulating nozzle side, so that a large amount of gas can flow out at once from the gas insulating nozzle. Further, the gas pressure in the boosting chamber can be sufficiently increased by the preceding arc generated on the first arc rotating electrode side. Therefore, it is possible to increase the gas blowing to the arc at the moment when the movable contact comes off the insulating nozzle, and the arc is formed by a synergistic effect of the gas blowing and the gas blowing relatively generated by the high-speed rotation of the arc. It is possible to effectively cool and improve the breaking performance.

Embodiment An embodiment of the present invention will be described below with reference to the accompanying drawings.

1 to 3 show a main part of a shut-off unit according to a first embodiment of the present invention. FIG. 1 is a longitudinal sectional view showing a closed state, and FIG. FIG. 3 is a vertical sectional view showing a cut-off state.

In these figures, reference numeral 11 denotes a cylindrical boosting chamber forming cylinder made of an insulating material or a conductive material. In this embodiment, the cylindrical body 11 is made of an insulating material, and an annular conductor 12 is attached to one end of the cylindrical body.
Are connected in a gas-tight manner. At the center of the annular conductor 12, a cylindrical protruding portion 12b protruding on the opposite side of the cylindrical body 11
Is provided, and a conductive plate 13 is attached so as to airtightly close the end of the protruding portion 12b. An insulating plate 14 is connected to the other end of the cylindrical body 11, and an insulating nozzle 15 sharing an axis with the cylindrical body 11 is provided at the center of the insulating plate 14. The cylinder 11, the annular conductor 12, the conductive plate 13, and the insulating plate 14 form a boosting chamber 16.

The inner end of the conductor 13 is connected to the rear end of an annular fixed contact 17 sharing an axis with the insulating nozzle 15. The fixed contact 17 is configured such that its tip is substantially flush with the inner surface of the plate-like portion 12a of the annular conductor 12, and a contact portion 17a is provided inside the tip of the fixed contact. A disk-shaped arc rotating plate 18 is fixed across the end of the fixed contact 17 and the inner surface of the annular conductor plate-shaped portion 12a. The rotating plate 18 is made of an arc-resistant conductive material such as a W-Cu sintered alloy, and has a central portion provided with a hole 18 a having an inner diameter slightly larger than the inner diameter of the fixed contact 17.

In the gas space between the fixed contact 17 and the insulating nozzle 15 in the booster chamber 16, the arc drive coil 20 is provided with a fixed contact.
It is arranged coaxially with 17. This arc drive coil 20
Is disposed in a support cylinder 21 made of an insulating material, and the support cylinder 21 is provided via a support arm 22 provided radially.
It is supported by the inner surface of.

An annular first arc rotating electrode 23 is electrically connected to an end on the fixed contact side of the arc driving coil 20, and a second arc rotating electrode 24 is electrically connected to an end on the insulating nozzle side. The first arc rotating electrode 23 is formed in a shape having a plate portion 23a and a cylindrical portion 23b.
3a is arranged along with the end face of the arc drive coil 20 on the fixed contact side. Second arc rotating electrode 24
Is formed of a plate formed in an annular shape, and is arranged along the end face of the arc drive coil 20 on the insulating nozzle side.
The first and second arc rotating electrodes 23 and 24 are arc rotating plates.
Like 18, it is formed of an arc-resistant conductive material.

In this embodiment, an insulating sleeve 25 is disposed inside the arc driving coil 20, and the insulating sleeve 25 insulates the inner periphery of the second arc rotating electrode 24 and the inner periphery of the arc driving coil.

Reference numeral 26 denotes a rod-shaped movable contact. The movable contact passes through a linear moving path including a space inside the insulating nozzle 15 and a space inside the arc drive coil 20, and as shown in FIG. The input position to contact,
As shown in FIG. 3, it is provided so as to be displaced between a fixed contact and a blocking position which is separated from the insulating nozzle. In this example, the inner diameter of the cylindrical portion 23b of the first arc rotating electrode 23 is formed slightly smaller than the inner diameter of the insulating sleeve 25, so that the movable contact 26 does not directly contact the second arc rotating electrode 23. ing.

In order to prevent the pressure in the pressurizing chamber 16 from increasing when the movable contact 26 is inserted and hinder the insertion of the movable contact, the movable contact 26 is relatively loosely fitted to the nozzle 15 or an arc is inserted. When the pressure rises, the pressure in the pressurization chamber 16
It is desirable to make the inside and outside communicate with each other.

The above-mentioned components constitute a main part of the shut-off unit, and the shut-off unit is housed in a circuit breaker container (not shown) in which SF ₆ gas is sealed.

When the circuit breaker is in the closed state shown in FIG. 1, the conductive plate 13-fixed contact 17-movable contact 26-
The main circuit current flows through the path. When a cutoff command is given and the movable contact 26 separates from the fixed contact 17, an arc is generated between the two contacts. When the tip position of the movable contact 26 reaches a position below the first arc rotating electrode 23 (on the side of the nozzle 15), the arc moves to the arc rotating electrode 23 and the arc rotating plate 18 and the arc rotating electrode 23 Arc A occurs between them. With the energy of this arc A, the boost room
The gas in the chamber 16 is heated and expands, and the gas pressure in the pressurizing chamber rapidly increases.

When the tip of the movable contact 26 reaches a position below the second arc rotating electrode 24, an arc A ′ is generated between the movable contact 26 and the second arc rotating electrode 24, and the arc driving coil 20 arcs. Electric current flows. As a result, magnetic flux is generated from the arc driving coil, and the magnetic flux links the arcs A and A ', so that a rotating force is applied to the arcs A and A', and these arcs are formed along the arc rotating electrodes 23 and 24. Rotate at high speed. As a result, gas is blown relatively to the arcs A and A '.

When the movable contact 26 separates from the insulating nozzle 15, the gas in the boosting chamber 16 is released at a stretch through the insulating nozzle 15, so that the gas is strongly blown to the arc A 'and the arc disappears at the current zero point.

4 and 5 show a shut-off unit according to a second embodiment of the present invention. FIG. 4 shows a closed state, and FIG. 5 shows a cut-off state. In FIGS. 4 and 5, parts that are the same as the parts of the embodiment in FIGS. 1 to 3 are given the same reference numerals, and descriptions thereof will be omitted.

In this embodiment, the insulating nozzle 15 of the arc drive coil 20 is used.
An annular contact holding conductor 27 is in contact with the end on the side, and a contact 28 made of a tulip contact is attached to the conductor 27. A contact is provided on the outer periphery of the contact holding conductor 27.
A second arc rotating electrode formed in a bowl shape so as to cover 28
24 'is attached. The movable contact 26 inserted into the pressurizing chamber 5 through the insulating nozzle 15 contacts the fixed contact 17 through the space inside the arc drive coil 20 while keeping the contact with the contact 28. Other points are 1st
The configuration is the same as that of the embodiment shown in FIGS.

In this embodiment, since the movable contact 26 is electrically connected to the nozzle-side end of the arc drive coil 20 via the contact 28, the tip of the movable contact 26 is larger than the first arc rotating electrode 23. When moving downward, a current flows through the arc driving coil through the route of the fixed contact 17, the arc rotating plate 18, the arc A, the first arc rotating electrode 23, the arc driving coil 20, the contact 28, and the movable contact 26, The coil is excited. As a result, a magnetic flux is generated from the arc driving coil 20, and the magnetic flux links with the arc A.
Rotates between the first arc rotating electrode 23 and the arc rotating plate 18.

Along with the rotation of the arc, the gas in the R portion in the pressurizing chamber 16 rotates together with the arc, is agitated with the fresh gas Q by centrifugal force and thermal expansion due to the arc energy, and is pushed into the second arc rotating electrode 24. It is. As a result, the gas pressure in the pressurizing chamber 16 sharply increases.

When the movable contact 26 separates from the contact 28, an arc A 'is generated between the second arc rotating electrode 24' and the movable contact 26, and the arc is generated between the movable contact 26 and the arc rotating electrode 24 '. Rotate. Other operations are the same as those in the above-described embodiment.

According to the embodiment shown in FIGS. 4 and 5, the arc generated between the first arc rotating electrode 23 and the arc rotating plate 18 is moved between the second arc rotating electrode and the movable contact. Since the high-speed rotation can be performed before the arc A 'is generated, the breaking performance can be further improved as compared with the first embodiment.

[Effects of the Invention] As described above, according to the present invention, the arc drive coil is disposed in the space between the fixed contact and the insulating nozzle, and the space outside the arc drive coil is provided on both sides in the axial direction in the pressure-boosting chamber. Since the space is open, a large amount of gas can be discharged from the gas insulating nozzle at once at a moment when the movable contact comes off the insulating nozzle, and smoothly guides the gas in each part in the boosting chamber to the insulating nozzle side. Further, the gas pressure in the boosting chamber can be sufficiently increased by the preceding arc generated on the first arc rotating electrode side. Therefore, the blow of the gas to the instantaneous arc at which the movable contact comes off the insulating nozzle can be strengthened, and the arc can be effectively formed by the synergistic effect of the gas blow and the gas blow relatively generated by the high-speed rotation of the arc. This has the advantage that the breaking performance can be improved by cooling.

[Brief description of the drawings]

1 to 3 show a main part of a shut-off unit according to a first embodiment of the present invention. FIG. 1 is a longitudinal sectional view showing a closed state, and FIG. FIG. 3 is a longitudinal sectional view showing a cut-off state, FIG. 4 and FIG. 5 are longitudinal sectional views respectively showing a closed state and a closed state of a blocking unit according to a second embodiment of the present invention. 6 and 7 are longitudinal sectional views respectively showing a closed state and a closed state of a breaker of a conventional circuit breaker. 11 ………………………………………………………………………………………………………………………………………………………………………………………………….
17: fixed contact, 18: arc rotating plate, 20: arc drive coil, 21: support cylinder, 22: support arm, 23 ...
A first arc rotating electrode, 24... A second arc rotating electrode,
25 ... Insulation sleeve, 26 ... Movable contact.

Claims (3)

(57) [Claims] A pressure chamber provided with an insulating nozzle; a fixed contact provided in the pressure chamber with an axis shared by the insulating nozzle; and a fixed contact provided between the fixed contact and the insulating nozzle in the pressure chamber. An arc drive coil disposed coaxially with the fixed contact in a gas space; and an electric current being respectively supplied to the fixed contact side end and the insulating nozzle side end of the arc drive coil disposed coaxially with the arc drive coil. First and second arc rotating electrodes that are electrically connected to each other, and an input position that contacts the fixed contact through a passage including the inside of the insulating nozzle and the inside of the arc driving coil, and separates from the fixed contact and separates from the insulating nozzle. And a movable contact that is displaced between the gas breaker and a shutoff position. 2. The gas circuit breaker according to claim 1, wherein an insulating means for insulating the movable contact from the second arc rotating electrode is provided inside the arc driving coil. 3. The gas circuit breaker according to claim 1, wherein a contact for slidingly contacting the movable contact is connected to the second arc rotating electrode.