JP3132226B2 - 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 a gas circuit breaker using both a magnetic arc driven arc extinguishing method and a thermal puffer extinguishing method.

[0002]

2. Description of the Related Art A conventional gas circuit breaker using both a magnetic arc drive arc extinguishing method and a thermal puffer extinguishing method will be described with reference to the drawings. FIG. 3 shows a cross-section of the shut-off portion of the gas circuit breaker. The right side from the center line in FIG. 3 shows the closed state of the circuit breaker, and the left side shows the closed state. This blocking portion is housed together with the high voltage insulator gas such as SF ₆ circuit breaker vessel, not shown.

In the closed state of the circuit breaker shown on the right side of the figure, the movable contact 5 comes into contact with the fixed contact 1, and the current flows through the path of the upper terminal 8 -fixed contact 1 -movable contact 5. During the breaking operation of the circuit breaker, the movable contact 5 is moved downward by the operation mechanism (not shown), the fixed contact 1 and the movable contact 5 are separated, and an arc is generated between the contacts 1 and 5. When the movable contact 5 further moves downward, one end of the arc moves from the fixed contact 1 to the arc runner 7, and an arc is generated between the arc runner 7 and the movable contact 5. At this time, the current flows through the path of the upper terminal 8-fixed contact 1-coil 2-arc runner 7-arc-movable contact 5.

When a current flows through the coil 2, a magnetic field crossing the arc is generated. This magnetic field drives the arc, and the arc rotates at high speed on the arc runner 7 about the center line in the figure. Since the rotating motion of the arc blows gas relatively to the arc, an arc extinguishing action is performed on the arc, and the current is interrupted by the arc extinguishing action by the magnetic arc drive.

[0005] While the movable contact 5 closes the opening of the nozzle 4, the pressurizing chamber 3 is sealed. When the arc rotates at a high speed in the sealed pressurizing chamber 3, the pressurizing chamber 3
The gas inside is expanded and pressurized by the arc energy, and the high-pressure gas is accumulated in the pressurizing chamber 3. Then, when the movable contact 5 moves further downward and separates from the nozzle 4, the high-pressure gas stored in the pressurizing chamber 3 flows out to the outside exhaust side at a high speed through the opening of the nozzle 4. As a result, gas is blown to the arc generated between the arc runner 7 and the movable contact 5, and the current is interrupted by the arc extinguishing action of the heat puffer.

The inventors of the present invention have studied the arc extinguishing performance of a gas circuit breaker using the above-described magnetic arc drive and heat puffer together, and have found the following. The principle of the arc extinguishing performance will be described with reference to FIG. As described above, as the movable contact 5 moves, the interruption by the magnetic arc drive and the interruption by the thermal puffer are performed. In the conventional gas circuit breaker, a breakable region A by magnetic arc drive and a breakable region B by a heat puffer exist in correspondence with the process in which the movable contact 5 is separated from the fixed contact. It has been found that there is a region between B, where no arc extinguishing action is performed and a cut-off is not possible.

[0007]

As described above,
In the conventional gas circuit breaker using both the magnetic arc drive and the heat puffer, any of the gas breakers that can be cut off by the magnetic arc drive from the time when the cutoff area A reaches the limit to the time when the next heat puffer can be cut off the area B starts. There is a region where the arc extinguishing operation is not performed and the cutoff cannot be performed. For this reason, in order to secure a continuous interruptable area of a certain level or more necessary for a circuit breaker,
Since the region A alone is insufficient, the arc time is extended as a whole because the region is secured only in the shuttable region B. Further, there is a problem that the contact length increases due to an increase in the arc length, and the life of the contact is shortened.

In view of this point, the present invention increases the continuous interruptable area of the gas circuit breaker, obtains a stable interrupting performance, and sets the continuous interruptable area required as a circuit breaker to be a predetermined or more interruptable area with an arc time. An object of the present invention is to secure a short portion, further reduce the damage of the contact, and prolong the life of the contact.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a boosting chamber formed in a container having a nozzle, a fixed contact and an arc driving coil housed in the boosting chamber, and the nozzle. And a movable contact which comes into and out of the pressurized chamber through the fixed contact and separates from the fixed contact. The gas circuit breaker combines an arc extinguishing action by a magnetic arc drive and an arc extinguishing action by a heat puffer. By partially overlapping an area that can be cut off by the arc extinguishing action and an area that can be cut off by the arc extinguishing action of the thermal puffer in the process of separating the movable contact from the fixed contact, The entire blockable area in the separating process is a continuous area.

[0010]

According to the above-mentioned means, in the moving process of the movable contact, before the cut-off area by the magnetic arc reaches the limit, the cut-off area is successively formed by the heat puffer. Regions which can be continuous and which cannot be interrupted without any arc extinguishing action are eliminated. As a result, the continuous breakable area of the gas circuit breaker can be lengthened, and stable breaking performance can be obtained, and a necessary break area can be secured in a short arc time area, so that damage to the contact is reduced.

[0011]

An embodiment of the present invention will be described with reference to the drawings. FIG.
Indicates a cross section of the shutoff portion of the gas circuit breaker. The right side from the center line in FIG. 1 shows the closed state of the circuit breaker, and the left side shows the closed state. This cut-off portion is provided with SF in a circuit breaker container (not shown).
It is housed with ₆ gases and placed in a high pressure insulating gas atmosphere. FIG. 2 is a diagram for explaining arc extinguishing performance in the present embodiment.

The pressure chamber 3 is formed by the insulating container 6 and the upper terminal 8, and the nozzle 4 is formed in a part of the container 6. The fixed contact 1, the coil 2, and the arc runner 7 are attached to the upper terminal 8 and housed in the boosting chamber 3. The upper terminal 8, the fixed contact 1, the coil 2, and the arc runner 7 are electrically connected in series. The movable contact 5 that comes into contact with and separates from the fixed contact 1 is driven in the vertical direction in the figure by an operating mechanism (not shown), and enters and exits the pressurizing chamber through the nozzle 4 provided in the container 6.

In the closed state of the gas circuit breaker shown on the right side of the drawing, the movable contact 5 comes into contact with the fixed contact 1 and the current is applied to the upper terminal 8 -fixed contact 1 -movable contact 5
It flows through the route. At this time, the movable contact 5
Blocks the opening of the nozzle 4, so that the pressurizing chamber 3 is sealed.
In the shut-off state of the gas circuit breaker shown on the left side in the figure, the movable contact 5 is separated from the fixed contact 1 and is outside the pressure boosting chamber 3, so that the pressure boosting chamber 3 communicates with the exhaust side outside the container 6 via the nozzle 4.

Next, at the time of the breaking operation of the circuit breaker, the movable contact 5 is moved downward in the figure by an operating mechanism (not shown) from the closed state on the right side in the figure. Thereby, the fixed contact 1 and the movable contact 5 are separated, and an arc is generated between the contacts 1 and 5. When the movable contact 5 further moves downward, one end of the arc moves from the fixed contact 1 to the arc runner 7 and the arc is moved to the arc runner 7.
And between the movable contact 5. At this time, the current flows through the path of the upper terminal 8-fixed contact 1-coil 2-arc-arc runner 7.

When a current flows through the coil 2, a magnetic field crossing the arc is generated, and the magnetic field drives the arc. Therefore, the arc rotates at a high speed on the arc runner 7 about the illustrated center line. Rotating the arc at high speed in the insulating gas is equivalent to relatively blowing the gas on the arc, so that the arc is extinguished, and the arc is extinguished by the magnetic arc drive. The action causes a current interruption. The area that can be cut off by the magnetic arc drive is shown as A in FIG. In the figure, during the process of moving the movable contact 5 away from the fixed contact 1, the tip position of the movable contact 5 is set to A.
When the current is in the range shown in FIG. 7, the current is interrupted by the arc extinguishing action by the magnetic arc drive.

On the other hand, when the current zero point is longer than the interruptable area A by the magnetic arc driving, the arc continues further, and the magnetic arc driving also continues. During this time, since the movable contact 5 closes the opening of the nozzle 4,
Is sealed by the container 6 and the upper terminal 8. When the arc rotates at high speed in the sealed pressurizing chamber 3, the pressurizing chamber 3
The gas inside is expanded and pressurized by the arc energy, and the high-pressure gas is accumulated in the pressurizing chamber 3.

When the movable contact 5 moves further downward and separates from the nozzle 4, the high-pressure gas stored in the pressurizing chamber 3 flows out to the external exhaust side at a high speed through the opening of the nozzle 4. Thereby, gas is blown to the arc generated between the arc runner 7 and the movable contact 5 through the nozzle 4, and the current is interrupted by the arc extinguishing action of the thermal puffer. The area that can be cut off by the heat puffer is shown as B in FIG.

In this embodiment, as shown in FIG.
During the moving process of the movable contact 5, a part of the two regions A and B are overlapped so that the interruptable region B by the thermal puffer is started before the interruptable region A by the magnetic arc reaches the limit. I have. In order to partially overlap the two regions A and B, the position of the nozzle 4 or the position of the nozzle 4 is set so that the movable contact 5 comes out of the opening of the nozzle 4 before reaching the limit of the interruptable region A by the magnetic arc drive. Set the shape.

By setting the areas A and B as described above, the shuttable area of the entire gas circuit breaker is shown in FIG.
become that way. As is clear from comparison with the above-described conventional example, the region C of the present embodiment has no non-interruptible region in which no interruption is performed during the process of separating the movable contact 5. As a result, the continuous cut-off possible area C
Has a longer overall length, a stable breaking performance can be obtained, and a continuous breaking area required as a breaker can be secured in a short arc time area. For this reason, the arc time width specified in the standard can be ensured in a region where the arc time is short, and damage to the contact due to the arc is reduced, and the life of the contact is extended. Further, in the portion where the regions A and B overlap, the magnetic arc drive and the thermal puffer affect each other, and stable arc extinction is performed.

[0020]

According to the present invention, since the continuous breakable region of the gas circuit breaker can be lengthened, stable breaking performance can be obtained, and the continuous breaker required as a breaker in a short arc time region can be obtained. A secure area can be secured, and damage to the contact can be reduced.

[Brief description of the drawings]

FIG. 1 is a side sectional view of an embodiment of the present invention.

FIG. 2 is a schematic diagram for explaining the arc extinguishing performance of FIG. 1;

FIG. 3 is a side sectional view of a conventional example.

FIG. 4 is a schematic diagram for explaining the arc extinguishing performance of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Fixed contact 2 ... Coil 3 ... Step-up chamber 4 ... Nozzle 5 ... Movable contact 6 ... Container 7 ... Arc runner 8 ... Upper terminal A ... Blockable area by magnetic arc drive B ... Blockable area by thermal puffer C ... Blocking of whole Possible area

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01H 33/70 H01H 33/985

Claims (1)

(57) [Claims] A pressurizing chamber formed in a container having a nozzle, a fixed contact and an arc driving coil housed in the pressurizing chamber, and a fixed contact that enters and exits the pressurizing chamber through the nozzle. In a gas circuit breaker having a movable contact that is separated from and in contact with each other, and the arc extinguishing action by a magnetic arc drive and the arc extinguishing action by a heat puffer are combined, the pressurizing chamber may be configured such that the movable contact has an opening of the nozzle
When the nozzle is closed, the nozzle is sealed.
Can be shut off by the magnetic arc drive during the shut-off operation
Before the area limit is reached, the movable contact
The movable contact opens from the fixed contact to a region where interruption can be performed by an arc extinguishing action by magnetic arc driving and an area that can be interrupted by an arc extinguishing action by a thermal puffer. A gas circuit breaker characterized in that by partially overlapping in a separating step, an entire shuttable area in a separating step of the movable contact is a continuous area.