JPH0770279B2 - Puffer type gas circuit breaker - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a puffer type gas circuit breaker among high-pressure gas blow circuit breakers used in substations or switchyards of electric power systems, and particularly to a circuit breaker. The present invention relates to a puffer type gas circuit breaker in which an arc extinguishing chamber has been improved to improve the breaking performance.

[Technical background of the invention] With the increase in electric power demand, the power plant and substation are steadily increasing in capacity. Moreover, due to the difficulty in constructing a power plant in an urban area, which is a region where a large amount of electricity is consumed, the power transmission line has a long distance, and the power transmission system tends to have a high voltage in order to improve the power transmission efficiency.

With the increase in capacity of such power transmission systems, the breaking capacity required for circuit breakers used in substations and switchyards has also increased, and at present, a breaking current of 63KA has been put to practical use in 550KV systems. There is. This 550KV-63KA is composed of 4 points, and if this is applied to the 1000KV system as it is, it will correspond to 8 points. In order to improve the reliability of the breaker, it is important to reduce the number of breaking points and the number of parts as much as possible, so that it is necessary to increase the breaking capacity per breaking point.

By the way, puffer-type SF ₆ gas circuit breakers are mainly used for transmission voltage of 168 KV or more. This is due to the excellent breaking performance and insulation performance of SF ₆ gas, but the puffer type is the mainstream of high-voltage breakers because it has a simpler structure than the two-pressure type. Also, the entire substation equipment
It is especially often used in a closed gas switchgear where insulation is provided by SF ₆ gas, because it has great advantages in coordinating the insulation with other equipment or the arrangement of equipment.

An example of the arc-extinguishing chamber of the gas breaker of such a puffer type gas breaker is shown in FIG. This arc extinguishing chamber is housed in a container (not shown) in which an arc extinguishing gas such as SF ₆ gas is sealed.

In FIG. 3, the puffer piston 1 is fixed to a container (not shown) via an insulator.
A puffer cylinder 2 that slides on the outer circumference of the piston and an operation rod 3 that slides on the inner peripheral surface of the puffer piston 1 are mounted around the. One end of the operation rod 3 is connected to an operation mechanism (not shown), and the movable electrode 4 and the puffer cylinder 2 are fixed to the other end of the operation rod 3, respectively. The operation rod 3 is driven by the operation mechanism. When the movable electrode 4 is opened and closed accordingly, the movable electrode 4 electrically opens and closes between the fixed electrode 5 facing the movable electrode 4.
At this time, the puffer cylinder 2 generates a compressed gas therein by a relative movement between the puffer cylinder 2 and the puffer piston 1. This compressed gas is ejected through an insulating nozzle 6 arranged around the movable electrode 4 and fixed to the tip of the puffer cylinder 2, and becomes a high-speed gas flow, which is generated between the electrodes 4 and 5 when the current is cut off. The arc 7 is actuated to perform the blocking operation. The insulating nozzle 6 has a minimum diameter portion 6a (throat) formed on the side facing the fixed electrode 5, whereby the compressed gas has a high-speed gas flow.

FIG. 4 is a diagram showing insulation recovery characteristics when a 420 KV class advanced small current interruption is carried out using the arc-extinguishing chamber shown in FIG. According to the JEC standard, the peak value of the recovery voltage after the forward small current cutoff is 960KV (430 × √2 / √3 × 2 × 1.4 = 96
Reach 0). In order to make an arc-extinguishing chamber that can withstand this high recovery voltage, it is necessary to either relax the electric field between the fixed electrode and the movable electrode or increase the contact opening speed.

[Problems of the Background Art] However, conventionally, it was difficult to satisfy only one of the above two conditions, and it was not possible to obtain an arc-extinguishing chamber having a high recovery voltage.

First, although there are various methods for implementing the former electric field relaxation, there is a limit to the improvement of the insulation recovery characteristics by the electric field relaxation between the electrodes when the opening speed is constant.

On the other hand, it is considered that the driving force is increased to improve the latter opening speed. Here, assuming that the driving force F, the opening stroke l, the moving part weight M, and the speed v, the relationship between the kinetic energy and the driving energy is approximately Fl≈ (1/2) Mv ² .

For example, if the moving part weight M is fixed and the speed is increased by 1.5 times, the kinetic energy becomes 2.25 times, and if the stroke 1 is constant, the driving force must be 2.25 times. In addition, even if the stroke is 1.5 copies, the driving force will be 1.5 times. In order to increase the driving force, it is necessary to increase the size of the driving device, but in this case, not only the cost increases but also the weight of the driving device increases. Furthermore, if the opening speed is increased, the seal between the container and the sliding part, the strength of the parts,
Phenomena such as impact force that should be newly considered are expected, and improvement of mechanical strength of each part at a level beyond the conventional design concept,
It is also necessary to strengthen the gas seal.

If the opening speed is increased by 1.5 times without changing the driving force F and the stroke l, it is necessary to increase the weight of the movable part by 1 / 2.25 times. In order to reduce the weight of conventional moving parts by 1 / 2.25 times, it is necessary to adopt new materials that are lighter and strengthened, or to make the wall thickness as thin as possible. The adoption of new materials
Although it has been done in part, it is very difficult to increase the weight of moving parts by 1 / 2.25.

[Object of the Invention] The present invention has been proposed in order to eliminate the above-mentioned drawbacks of the prior art, and does not require special mechanical strength improvement, gas seal portion strengthening, etc. At the level of the design concept of, the insulation recovery characteristic was improved by enabling the opening speed to be increased while keeping the driving force almost the same as before, and it became possible to cut off even when the rated voltage became extremely high. It is to provide a highly reliable puffer type gas circuit breaker.

SUMMARY OF THE INVENTION According to the present invention, a link device having a support point which reverses a direction of a driving force is provided on a drive device side of an operating rod, and one end of the link device is connected to the operating rod, and the link device is provided. Provided is a puffer type gas circuit breaker in which the other end and a counter electrode facing a movable electrode are connected by an insulating rod, and a puffer piston is connected to the insulating rod.

With the above configuration, when the driving device is driven, the movable electrode and the counter electrode are driven in opposite directions, respectively, and thus the speed at which the movable electrode and the counter arc electrode are separated and the speed at which they are in contact with each other. Can be relatively fast, and therefore
The opening speed can be improved while the driving force is the same as before, and by connecting the puffer piston to the insulating rod, the puffer paston operates in the direction opposite to the movement direction of the puffer cylinder, so It is possible to improve the compression efficiency of the space formed by.

[Embodiment of the Invention] An embodiment of the puffer type gas circuit breaker according to the present invention as described above will be described with reference to FIG. The same parts as those of the related art are designated by the same reference numerals and the description thereof will be omitted.

FIG. 1 is a diagram showing the vicinity of the arc-extinguishing chamber in the closed state, and shows the closed state. In FIG. 1, an insulating rod 8 is arranged on the outer circumference of the puffer cylinder 2 so as to maintain a constant distance from the puffer cylinder 2 and coaxial therewith. The insulating rod 8 is connected to the puffer piston 1 at the end on the operating mechanism side, and is also connected to the operating rod 3 via a link device 9 provided near the driving device side of the operating rod 3. . The link device 9 includes a link 9a, first and second connecting rods 9b and 9c rotatably connected to both ends of the link 9a, and a link support portion 9d that supports the link 9a. The link 9a is rotatably supported with respect to the link support portion 9d about a fulcrum 9e of the link support portion 9d set to a predetermined link ratio, and each of the first and second connecting rods. Each of 9b and 9c is rotatably connected to the operation rod 3 and the insulating rod 8 at one end thereof.
The link support portion 9d is fixed to an insulating cylinder 10 that is insulated and fixed to a container (not shown).

On the other hand, a current-carrying cylinder 11 is coaxially attached to the end of the insulating rod 8 on the side opposite to the operating mechanism. The current-carrying cylinder 11 is a current-carrying conductor for insulation and fixed from a container.
An energizing portion 12a formed inside 12 is slidably operable. A long opposing arc electrode 13 is provided on the axis line of the energizing cylinder 11 on the side of the operating mechanism, and constitutes the movable electrode 4 and the opposing electrode 14 for performing the opening / closing operation. The movable electrode 4 and the opposed arc electrode 13 are in contact with each other in the closed state of FIG.

The operation of this embodiment having the above configuration will be described below. Note that FIG. 2 is a diagram showing an open state of the arc extinguishing chamber of FIG. 1, and the movable electrode 4 and the counter electrode 14 are in a separated state.

First, in the closed state shown in FIG. 1, when an operating mechanism (not shown) is operated, the rod 3 is driven at a predetermined speed in the operating mechanism direction (rightward in the figure), and the movable electrode 4 fixed to the tip thereof. Moves to the right and shuts off from the counter electrode 14. On the other hand, as the operation rod 3 moves, a force is also applied to the first connecting rod 9b connected to the operating rod 3 in the same direction, and the force is applied to one end of the link 9a connected to the first connecting rod 9b. To move to the right in the figure. In this case, since the fulcrum 9e of the link 9a is fixed,
The above-mentioned force applied to one end of the link 9a causes the link 9a to be a fulcrum 9e.
Is used as a moment force to rotate in the counterclockwise direction, and the link 9a rotates in the same direction. Then, since the other end of the link 9a rotates leftward in the figure, the second connecting rod 9c connected to the same part moves leftward, and the insulating rod 8 and the puffer piston 1 connected to this move. Also moves to the left.
Therefore, the counter electrode 14 fixed to the insulating rod 8 moves to the left, separates from the movable electrode 4, and shifts to the open state as shown in FIG. That is, according to the operation of the operating rod 3, both the movable electrode 4 and the counter electrode 14 move in the cutting operation direction.

Further, the closing operation is similarly performed by driving the operation rod 3 in the direction opposite to the above-described cutting operation. That is,
When the operating rod 3 is driven leftward at a predetermined speed in the cutoff completion state of FIG. 2, the movable electrode 4 fixed to this moves leftward which is the contact direction with the counter electrode 14, while The link 9a rotates clockwise through the first connecting rod 9b. As a result, the second connecting rod 9c moves to the right, and the insulating rod 8 and the counter electrode 14 move to the right, which is the contact direction with the movable electrode 4.

Therefore, also in the closing operation, both electrodes move in the closing operation direction in accordance with the operation of the operating rod 3, similarly to the cutting operation.

As described above, in this embodiment, the movable electrode 4 and the counter electrode 4 are moved in accordance with the operation of the operation rod 3 in the closing and shutting operations.
Since 14 and 14 are driven in the opposite directions, respectively, the speed at which the movable electrode and the counter electrode are separated (cutting speed) and the speed at which they are in contact with each other (make-up speed) can be relatively increased.

For example, when the driving force is F and is constant and the counter electrode is not moved (that is, when the counter electrode is a fixed electrode), the stroke of the driving device is 1, the weight of the movable part is M, and the opening speed is v. Then, as mentioned above, Fl ≈ (1/2) Mv ² .

On the other hand, in the case of this embodiment in which the counter electrode is moved, when the link ratio is 1: 2, the stroke of the drive device is
(2/3) l is enough. Moreover, the weight of the counter electrode and the movable electrode on the side of the driving device is about 1.5 times M.
Furthermore, since the relative velocity of the opposing electrodes may be v, the velocity of the opposing electrode is (1/3) v and the velocity of the movable electrode is (2/3) v.
Can be distributed so that Therefore, the driving force is F
, The kinetic energy is F × (2/3) × 1 ≒ (1/2) × (1.5M) × {(2/3) v} ² = (2/3) × {(1/2 ) × Mv ² }, the kinetic energy is about 2/3, whereas the velocity is v when the counter electrode is not moved.

In other words, if the counter electrode is not moved, the stroke will eventually become long and the opening speed will not be increased. Therefore, the drive device based on the same design concept as before cannot withstand high speed, and You have to improve the physical strength. Further, the gas seal portion also deteriorates faster due to the higher speed, so that it becomes necessary to strengthen it.

On the other hand, when the counter electrode is operated as in the present invention, the stroke can be adjusted to the driving device which has been conventionally used by changing the link ratio. Further, the opening speed of the movable part can be slowed down and the conventional design concept can be used for designing, so there is no need to improve mechanical strength or strengthen the gas seal part.

Further, particularly in the above embodiment, since the insulating rod 8 and the puffer piston 1 are connected, the puffer piston 1
Operates in the direction opposite to the moving direction of the puffer cylinder 2, the gas compression efficiency of the space formed by the puffer piston 1 and the cylinder piston 2 is also improved, and even if the diameter of the puffer cylinder 2 is small, the relative speed v The same pressure rise can be expected.

The present invention is not limited to the above-described embodiment, and for example, the link ratio between the movable electrode side and the counter electrode side can be freely selected, and the configuration of the counter electrode can be freely selected. Further, a sufficient effect can be obtained without necessarily connecting the insulator and the puffer piston.

As described above, according to the present invention, the movable electrode and the counter electrode are driven in opposite directions, and the puffer piston is connected to the insulating rod to drive the puffer piston as well. At the level of the conventional design concept, it was possible to improve the opening speed and the gas compression efficiency while keeping the driving force almost the same as the conventional one, so that the insulation recovery characteristic was improved and even when the rated voltage became extremely high. It is possible to provide a highly reliable puffer type gas circuit breaker that can be cut off. Particularly, in the present invention, since the link device which reverses the direction of the driving force and has the supporting point is connected to the drive device side of the operation rod, and the counter electrode facing the movable electrode is connected to this link device through the insulating rod. , The movable electrode and the insulating rod move in opposite directions when the electrode is turned on. Therefore, tensile stress is applied to the insulating rod when the electrodes come into contact with each other. In general, an elongated rod-like object such as an insulating rod is much weaker than a compressive stress in the axial direction as compared with a tensile stress and may be buckled or broken. With this configuration, there is no fear of damage to the insulating rod and the reliability of the device is improved.

[Brief description of drawings]

1 and 2 are cross-sectional views of an arc-extinguishing chamber showing an embodiment of the puffer type gas circuit breaker according to the present invention. FIG. 1 is a closed state, FIG. 2 is an open state, and FIG. FIG. 4 is a sectional view showing an example of an arc extinguishing chamber of a conventional puffer type gas circuit breaker,
The figure shows the insulation recovery characteristics after 420 KV class small current break. 1 ... Puffer piston, 2 ... Puffer cylinder, 3
...... Insulating rod, 4 ...... Movable electrode, 5 ...... Fixed electrode, 6
…… Insulation nozzle, 7 …… Arc, 8 …… Insulation rod, 9
...... Link device, 9a ...... Link, 9b, 9c ...... Connecting rod, 9d
…… Link support, 9e …… Link fulcrum, 10 …… Insulation rod,
11 …… energizing cylinder, 12 …… energizing conductor, 13 …… facing arc electrode.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoru Yanagisa 2-1, Ukishima-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Inside the Hama-Kawasaki Plant, Toshiba Corporation (72) Hirokazu Takagi Second, Ukishima-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa No. 1 Incorporated company Toshiba Hamakawasaki Factory (56) References JP-A-51-89157 (JP, A) JP-B-50-7269 (JP, B1) JP-B-26-14626 (JP, Y1)

Claims (3)

[Claims] Claims: 1. A contactable and separable electrode is arranged to face each other in a container in which an arc extinguishing gas such as SF ₆ gas is sealed, and a movable electrode, which is one of the facing electrodes, and a puffer cylinder are driven. An arc-extinguishing gas in the puffer cylinder is fixed by one end of an operation rod connected to the device, and the puffer cylinder and a puffer piston having a hole through which the operation rod slides are fixed by the puffer cylinder. A puffer-type gas circuit breaker that compresses the compressed gas and ejects this compressed gas as a high-speed gas flow from an insulating nozzle that is concentrically fixed to the outside of the puffer cylinder and blows off the arc generated between the opposing electrodes to extinguish the arc. In the driving device side of the operating rod, a link device having a supporting point that reverses the direction of the driving force is provided, and one end of the link device is connected to the operating rod. A counter electrode opposed to the other end and the movable electrode of the sink device connected by insulating rods, puffer type gas circuit breaker, characterized in that said puffer piston coupled to the insulating rod. 2. The support point of the link device is arranged at a position where the link ratio between the operation rod side and the counter electrode side facing the movable electrode is 2: 1 or more.
The puffer type gas circuit breaker described in the item. 3. A counter electrode facing the movable electrode has a structure in which a counter arc electrode is attached to a coaxial current-carrying cylinder, and the current-carrying cylinder is insulated and fixed from a container and has a current-carrying conductor having a current-carrying portion inside. The puffer type gas circuit breaker according to claim 1, characterized in that it slides.