JPH034418A - Buffer type gas breaker - Google Patents

Abstract

PURPOSE:To break a large capacity, enhance reliability and enable miniaturization by setting a closing speed of a closing resistant contact higher than a relative closing speed of first and second movable electrodes constituting a main contact, and keeping the closing resistant contact in a switched state even in the closing state of the main contact. CONSTITUTION:A closing resistant contact movable electrode 46 is driven by a resistant contact operating cylinder 50 in association with a main contact operating cylinder 35. A closing speed of the closing resistant contact movable electrode 46 is set higher than a relative closing speed of two movable electrodes 1, 10 constituting a main contact in an arc extinguish chamber 30 in such a manner that the closing resistant contact is switched during closing of the main contact. Therefore, a device as a whole can be constituted compact, and further, decrease in closing overvoltage in closing or an insulative recovery speed of the closing resistant contact in closing can be improved, thus enhancing reliability.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a large-capacity one-off, closing contact, and a buffer type gas circuit breaker with closing resistance, such as for a 550 KV system. .

(Prior Art) As the capacity of power transmission systems increases, the breaking capacity of circuit breakers used in substations and switchyards increases, and high reliability is required. In order to improve the reliability of circuit breakers, it is important to reduce the number of parts and simplify the structure. Therefore, efforts are being made to reduce the number of breaking points of circuit breakers. For example, currently in the 550 KV system, a two-point circuit breaker with a breaking current of 50 KA is in practical use, but there is a demand for a one-point circuit breaker.

By the way, in order to improve the arc extinguishing performance when converting such a large-capacity circuit breaker to one point, it is necessary to make the opening speed much faster than that of a conventional two-point circuit breaker. There is. Therefore, unlike conventional circuit breakers, which are equipped with a fixed electrode and a movable electrode facing the fixed electrode and move only the movable electrode when opening, we have developed a so-called double-motion circuit breaker that opens the circuit by simultaneously moving two opposing electrodes. A circuit breaker called According to this double-motion type circuit breaker, although the moving speed of each electrode is similar to that of a conventional circuit breaker, the opening speed is much faster and the arc extinguishing performance is improved.

An example of such a double motion type circuit breaker is shown in the sixth section.
It is shown in FIG.

In this figure, 1 is a first movable electrode, and 10 is a second movable electrode (corresponding to a conventional fixed electrode). The first movable electrode 1 is provided at the tip of the buffer cylinder 2,
An insulating nozzle 3 and a movable current-carrying contact 4 are arranged concentrically around its outer periphery.

An operating rod 5 is fixed to the center of the buffer cylinder 2, and the operating rod 5 is connected to a mechanism (not shown) via an insulating rod 6. A buffer piston 8 fixedly supported by an insulating cylinder 7 is inserted inside the buffer cylinder 2, and a space surrounded by the buffer piston 8 and the buffer cylinder 2 forms a buffer chamber 9.

The second movable electrode 10 is provided so as to protrude from the center of the face of the current-carrying cylinder 11 facing the first movable electrode 1, and is inserted into the insulating nozzle 3 and the first movable electrode 1. On the outer periphery of the second movable electrode 10, there is a second movable current-carrying contact 12 that contacts the movable current-carrying contact 4 of the first movable electrode.
A movable shield 13 is provided. The current-carrying cylinder 11 that supports these second movable electrodes 10 is slidably inserted into the current-carrying conductor 14 at its base, and at the same time an insulating rod 15 and a link are provided outside the first movable electrode 1. It is connected via a mechanism 16 to the base of the operating rod 5 that drives the first movable electrode 1 . This link mechanism 1
Reference numeral 6 denotes first and second connecting rods 16b, 16c and a link 16 rotatably connected to both ends of the link 16a.
The link support section 16d supports the link a.

The link 16a rotates around the fulcrum 16e of the link support 16d, which is set to a predetermined link ratio.
It is rotatably supported with respect to d.

Further, each of the first and second connecting portions 16b and 16c is rotatably connected to the operating rod 5 and the insulating rod 15 at one end of each. Note that the link support portion 16d is fixed to an insulating cylinder 9 that is insulated and fixed to a container (not shown).

In the double-motion circuit breaker configured in this way, when the operating mechanism (not shown) is driven in the closed state shown in FIG.
The first movable electrode 1 fixed to the tip thereof moves rightward, and a disconnection operation is performed between the first movable electrode 1 and the second movable electrode 10. On the other hand, as the operating rod 5 moves, a link mechanism 16 connected thereto is driven, and the insulating rod 15 is moved to the side opposite to the operating rod 5 (to the left in the figure). As a result, the current-carrying cylinder 11 and the second movable electrode 10 fixed to the tip of the insulating rod 15 move in the opposite direction to the first movable electrode 1 (to the left in the figure). Also,
As the operating rod 5 moves, the buffer cylinder 2 fixed at its tip moves relative to the buffer piston 8 fixed to the insulating cylinder 7, and the buffer chamber 9 is compressed, so that the arc extinguishing gas inside is insulated. The arc is blown between the first and second electrodes which are guided by the nozzle 3 and separated, thereby extinguishing the arc.

Note that the closing operation is performed by driving the operating rod 5 in the opposite direction to the closing operation.
10 relatively close together.

In this way, in a double-motion type circuit breaker, although the moving speed of the operating rod 5 is similar to that of a conventional circuit breaker, since it drives both the first and second movable electrodes 1. The relative opening speed between them is more than doubled, making it possible to trip at one point even in large-capacity circuit breakers.

(Problems to be Solved by the Invention) By the way, in circuit breakers for lines in large-capacity systems such as 550 KV class, a closing resistance method is adopted in order to suppress the closing overvoltage at the time of closing. In this system, a closing resistance contact with a closing resistance is installed in parallel with the main contact of the circuit breaker, and when the circuit breaker is closed, this closing resistance contact is closed before the main contact, and the closing overvoltage is suppressed by the closing resistance. is input. In this method, when opening, it is necessary that the making resistance contact first be opened, and then the main contact must be opened.

When this closing resistance contact is used in the above-mentioned double-motion type circuit breaker, the major problems are the reduction of switching overvoltage and the miniaturization of the circuit breaker and the entire gas-insulated switchgear that employs it, and it is difficult to solve these problems. This is an important issue.

First, Figure 8 shows the insulation recovery characteristics between the closing contact and the arc extinguishing chamber (main contact) per point of a conventional 550KV class two-point circuit breaker, and the closing contact and extinguishing point of a 550KV class single-point circuit breaker. The insulation recovery characteristics of the arc chamber are shown.

As is clear from this figure, in a 550 KV class single-point circuit breaker, the opening speed of both the main contact and the closing resistance contact is faster than in the case of two-point circuit breakers, each with one point.

■ When opening, the insulation recovery speed of the closing resistance contact is faster than that of the main contact.

■ At the time of closing, the closing resistance contact is closed before the main contact.

It is necessary to satisfy the following conditions.

However, in conventional circuit breakers in which only one electrode is movable, the movable electrode and the closing resistance contact are moved simultaneously at the same speed using the same drive source, and the timing of opening or closing of both depends on the shape of the electrode. (The main contact has an electrode structure using a wipe, while the closing resistance contact uses a butt contact using a spring.)

However, in the double motion method adopted for 55 OKV class single-break circuit breakers, the picture electrodes at the main contact move simultaneously, so the closing resistor contact opens at the same speed as the opening speed of the main contact, unlike conventional circuit breakers. If the closing resistance contact is moved, the closing or opening speed of the closing resistance contact will be approximately 172 times that of the main contact, and as mentioned above, the closing or opening speed of the closing resistance contact cannot be made faster than that of the main contact. A problem arises. Moreover, as this type of large capacity circuit breaker,
The reason for this is that while a buffer type gas circuit breaker is used that sprays arc-extinguishing gas between the electrodes of the main contact when opening, no arc-extinguishing gas is sprayed on the closing resistance contact. Also, it was difficult to make the insulation recovery speed of the closing resistance contact faster than that of the main contact.

In addition, in conventional circuit breakers with closing resistance contacts,
Because the arc extinguishing chamber housing the main contact and the closing resistance contact were housed in the same container, the outer diameter of the entire container became larger, and at the same time, the entire gas-insulated switchgear that used it also became larger. There were also drawbacks. For example, FIG. 9 is a plan view of a gas-insulated switchgear using conventional circuit breakers housed in the same container. When the circuit breaker 23 with a closing resistance contact is connected to the circuit breaker 23 with a closing resistance contact through the current transformer 24, and this is further connected to the bushing 25 on the line side through the current transformer 24, if the outer diameter of the container of the circuit breaker 23 of each phase is large, the When the circuit breaker 23 is installed, the dimension between the phases increases, which increases the space occupied by the gas-insulated switchgear, and also increases the length of the three-phase bracket bus 20, which is difficult and expensive to manufacture. was there.

Furthermore, circuit breakers with closing resistance contacts are used for normal line circuits, and circuit breakers without closing resistance contacts are used for other line sections. Even for circuit breakers that do not require a closing resistor contact, a container large enough to accommodate the closing resistor contact is commonly used. Problems also occurred in other parts of gas-insulated switchgear.

The present invention solves the problems of the prior art as described above, is miniaturized, and contributes to the downsizing of the entire gas-insulated switchgear,
Moreover, the purpose is to provide a highly reliable, large-capacity, single-break buffer type gas circuit breaker that can reduce the closing overvoltage at the time of closing and improve the insulation recovery speed of the closing resistance contact at the time of opening or closing. do.

[Structure of the Invention] (Means for Solving the Problems) In the present invention, a main contact consisting of a first and a second movable electrode is housed in an arc extinguishing chamber, and a fixed electrode and a fixed side electrode are arranged in parallel with the main contact. In a buffer type gas circuit breaker with a double-motion single-break closing resistance contact, which is equipped with a closing resistance contact section consisting of a movable side electrode and a closing resistor connected to these electrodes, the closing resistance contact is movable. The electrode is driven by a resistance contact operation cylinder that is linked with the main contact operation cylinder, and the closing speed of the movable electrode of the closing resistance contact is controlled by
The structural feature is that the closing speed is higher than the relative closing speed of both movable electrodes that constitute the main contact in the arc extinguishing chamber, and the closing resistance contact performs opening and closing operations during closing wipe of the main contact. It is.

(Function) In the buffer type gas circuit breaker of the present invention having the above configuration, when the closing resistance contact is opened during the closing wipe operation of both movable electrodes of the main contact and the main contact is in the closing stationary state, Since the closing resistance contact maintains the open state, there is no need to operate the closing resistance contact at high speed when the main contact opens, and it exhibits good insulation recovery characteristics.
It is also possible to provide good mechanical strength.

(Example) Hereinafter, an example of the present invention will be specifically described with reference to FIGS. 1 to 5. It should be noted that the same members as those of the conventional circuit breaker shown in FIG.

In this embodiment, as shown in FIG.
is stored in a dedicated arc extinguishing chamber storage container 31. The first movable electrode 1 located at the lower part of the arc extinguishing chamber 30 is electrically connected to a conductor 33 drawn out from an opening 32 on the lower side of the arc extinguishing chamber storage container 31 (to the side of the closing resistance contact storage container). It is connected. Further, the arc extinguishing chamber 30 is supported by an insulating tube 9 on an operating mechanism box 34 in which an arc extinguishing chamber storage container 31 is installed. In this arc extinguishing chamber 30, each movable electrode 1,
The operating rod 5 that drives the arc-extinguishing chamber 10 is extended into the operating mechanism box 34 via an insulating rod 6, and is connected to an operating rod 36 of an arc-extinguishing chamber operating cylinder 35 provided therein. On the other hand, the second movable electrode 1 located at the upper part of the arc extinguishing chamber 30
0 is connected to a conductor 38 drawn out from an outlet 37 provided at the upper part of the arc-extinguishing chamber storage container 31 via a current-carrying conductor 14.

Moreover, on the side of the arc extinguishing chamber storage container 31 as described above, a closing resistance contact storage container 40 which is a separate container is provided. This storage container 40 has openings 41 and 42 provided on the upper and lower sides of the side surface of the arc extinguishing chamber storage container 3.
1 is connected to an opening 39.32 formed in one side. A making resistance contact portion is housed in the making resistance contact storage container 40 . This closing resistance contact section is composed of a closing resistor 43, a closing contact fixed electrode 44, a spring 45 for returning the closing contact, and a closing contact movable electrode 46 facing the closing contact fixed electrode 44. Among these, the fixed side electrode 44 is connected via the closing resistor 43 to the conductor 38 connected to the second movable electrode 10 of the arc extinguishing chamber. Further, the movable electrode 46 is electrically connected to the conductor 33 connected to the first movable electrode 1 of the arc extinguishing chamber via a sliding part 47, and the base of the movable electrode 46 is connected to an insulating rod. 48 and the operating mechanism box 34 by the operating rod 49.
It is connected to the closing resistance contact operating cylinder 50 inside.

The closing resistance contact operation cylinder 50 is connected to the arc extinguishing chamber operation cylinder 35 through a hydraulic pipe 51 and is driven synchronously. Here, the arc extinguishing chamber operating cylinder 35 is configured as a system as schematically shown in FIG. 2. In other words, the operation cylinder 35 has a cylinder 351 and a piston 35.
A liquid chamber 351a on one side of the cylinder 351 with respect to the piston 352 is connected to an accumulator AL that stores pressurized liquid pressurized by the pump P. On the other hand, the liquid chamber 351b on the other side of the cylinder 351 is connected to the accumulator AL or the tank T via the control valve CV, and the operation of the control valve Cv is performed by the closing pilot valve PVI and the shutting pilot valve PV2. That is, by operating the pilot valves PVI and PV2, the control valve Cv switches the flow path, and the operating rod 36 engaged with the piston 352 is driven by charging and discharging the pressure liquid into the liquid chamber 351b.

On the other hand, the closing resistance contact operation cylinder 50 is shown in FIG. 3(A).
It is configured as shown in (B). That is, cylinder 5
01, liquid chambers 501a and 501b are formed by a piston 502 that engages with the operating rod 49 and slides on its inner surface.
is formed.

Further, the liquid chamber 501a is communicated with the liquid chamber 351b of the arc extinguishing chamber operating cylinder 35 via a supply valve 503, and is also communicated with the liquid chamber 501b via a discharge valve 504 provided in the piston 502. ing. Note that this supply valve 5
03 is driven in the left-right direction in the drawing by the hydraulic pressure in a valve chamber 503a provided at the back thereof and the force acting on a spring 505a provided in a valve chamber 503b provided at a position opposing the hydraulic pressure. By the operation of this supply valve 503, the seat portion 503C formed in the cylinder 501 is brought into contact with and separated from the seat portion 503C, and the flow path of the piping 51 connected to the liquid chamber 351b is connected to the liquid chamber 501a. Closing and communication with the flow path 506a are performed. Further, a flow path 506b communicating with the flow path of the piping 51 is connected to the valve chamber 503a.
is in communication with a low pressure flow path 506c connected to a tank (not shown).

On the other hand, the discharge valve 504 has a valve body 504a and a piston 502.
It consists of a valve rod 504b that penetrates and protrudes toward the liquid chamber 501b side, and is incorporated into the piston 502 together with a spring 505b that acts in a direction to push down the discharge valve 504. Then, the valve body 504a and the seat portion 504C come into contact,
By opening, the liquid chambers 501a and 501b are closed and communicated with each other, and when the piston 502 moves upward, the valve rod 50
The tip of the cylinder 4b is configured to abut against the upper end of the cylinder 501. Furthermore, inside the liquid chamber 501b, there is a spring 5 that acts to constantly push down the piston 502.
05c is provided and communicated with the low pressure flow path 506c.

In addition, in this embodiment, the conductor 38, which is arranged at the upper part of each storage container 31, 40 and connects the second movable electrode 10 and the fixed side electrode 44 of the closing resistance contact, is connected to the upper part of the arc-extinguishing chamber storage container 31. The conductor 33, which is disposed at the bottom of each storage container 31 and 40 and connects the first movable electrode 1 and the movable side electrode 46 of the making resistance contact, is connected to the making resistance contact storage container 40 from the opening 37.
is pulled out from the outlet 52 provided at the bottom of the
Connected to other equipment that makes up the gas-insulated switchgear. In addition, each outlet 37°52 of these storage containers has
Insulating spacers 53,54 are provided for supporting the conductors 33,38 and for gas separation with other equipment.

The operation of the buffer type gas circuit breaker of this embodiment having the above configuration will be explained.

1 and 3(A) show the open state, and in FIG. 3(A), the supply valve 503 is connected to the seat portion 50.
3c is held in an open state and communicates with the liquid chamber 351b of the arc extinguishing chamber operation cylinder 35 which is in a low pressure state.
is also maintained at low pressure. Therefore, due to the action of the spring 505c disposed inside the cylinder 501, the piston 5
02 is pressed against the bottom of the cylinder 501, and
The discharge valve 504 has a valve body 504a attached to the seat portion 504.
A force is applied to bring the liquid chambers 501a and 50 into contact with each other.
Communication between 1b is blocked.

At this time, when a closing command is input, pressure liquid is supplied into the liquid chamber 351b of the arc extinguishing chamber operation cylinder 35, and the operation rod 3
6 starts moving to the input side. At the same time, pressure liquid is supplied into the liquid chamber 501a of the closing resistance contact operation cylinder 50 via the piping 51 and the supply valve 503, so that the piston 502
starts moving toward the input side (upward in the figure) against the reaction force of the spring 505C in the liquid chamber 501b. During such operation of the piston 502, the discharge valve 504 receives the liquid pressure in the liquid chamber 501a, the seat portion 504C remains closed by the valve body 504a, while the supply valve 503 receives the liquid pressure in the liquid chamber 501a. 50
6b to the valve chamber 503b, the difference in pressure receiving area causes the direction of closing the seat portion 503C (
(in the figure, to the left).

The driving speed of the piston 502 is set to be at least twice the driving speed of the operating rod 36, and near the end of the movement toward the input side, the supply valve 503 closes to the seat portion 503c.
The discharge valve 504 is set so that the tip of the valve rod 504b of the discharge valve 504 comes into contact with the upper end of the cylinder 501.

At this time, the arc extinguishing chamber 30 is operated by the operating rod 36 on the arc extinguishing chamber side.
As described in the prior art, the first movable electrode 1 and the second movable electrode 10 are driven in opposite directions by the link mechanism 16, so the relative input speed of the two is controlled by the operating rod 3.
The driving speed is approximately twice as high as that of No. 6. On the other hand, in order to suppress overvoltage at the time of closing, the closing resistance contact side needs to be closed earlier than the high-speed closing of the arc extinguishing chamber 30 as described above, but in this embodiment, Since the closing resistance contact operating cylinder 50 drives its operating rod 49 at a speed faster than the relative speed of the first and second movable electrodes 1.10 within the arc extinguishing chamber 30, the closing resistance contact operates within the arc extinguishing chamber. The main contact is always closed before the main contact.As a result,
First, the movable side electrode 46 of the closing resistance contact is connected to its fixed side electrode 4.
4 and pushing it against the return spring 45, the conductors 33 and 38 are connected through the closing resistor 43, and then the arc extinguishing chamber 30 is opened at a speed slower than the closing speed of the closing resistor contact. The side main contact is closed in the manner described in the prior art section, resulting in an electrical connection between the conductors 33 and 38.

Further, FIG. 3(B) shows the closing state of the closing resistance contact operating cylinder 50. That is, when the piston 502 is completely closed, the tip of the valve rod 504b of the discharge valve 504 comes into contact with the upper wall of the cylinder 501, so that the piston 50
The discharge valve 504 is pushed down by the reaction force of the inertial force No. 2, and the valve body 504a opens the seat portion 504c. At approximately the same time, the supply valve 503 closes the seat portion 503C. As a result, the liquid chambers 501a and 501b are communicated with each other, and the communication between the liquid chamber 501a and the liquid chamber 351b is cut off.
b and is discharged via the low pressure flow path 506C, but the liquid chamber 3
The inside of 51b is maintained at high pressure. For this reason, the piston 50
2 starts the opening operation by the compressive force of the spring 505C, but this is set so that the contact point of the arc extinguishing chamber 30 completes the closing operation. Further, during the opening operation of the piston 502, the discharge valve 504 is maintained in the open state by the action of the spring 505b, so that the liquid pressure in the liquid chamber 501a does not rise excessively and interfere with the operation of the piston 502. I have to. Furthermore, since the supply valve 503 is kept closed by the hydraulic pressure in the valve chamber 503a, the arc extinguishing chamber operation cylinder 35 is kept in the closed state. Then, when the piston 502 completes the opening operation, the head of the valve body 504a of the discharge valve 504 comes into contact with the lower wall of the cylinder 501, compressing the spring 505b and closing the seat portion 504c. At this time, the supply valve 50
3 is closed, no liquid pressure is supplied into the liquid chamber 501a, and the contact does not operate in the closing direction again.

On the other hand, when an opening command is given with the arc extinguishing chamber operating cylinder 35 in the closed state, the pressure liquid in the liquid chamber 351b is discharged and the operating rod 36 moves to the opening side. Along with this, the pressure in the valve chamber 503a communicating with the flow path of the pipe 51 also becomes low, so the supply valve 503 moves rightward in the figure by the action of the spring 505a and returns to the open state, as shown in FIG. The state returns to the state shown in (A). In this way, when the main contact is opened, the electrodes 44 and 46 of the closing resistance contact are already in the open state, so there is no need to consider the insulation recovery speed of the resistance contact as in the conventional case.

The buffer type gas circuit breaker of this embodiment having the configuration and operation described above exhibits the following effects.

■ After the closing resistance contact is closed, it is automatically opened, so there is no need to move the closing resistance contact at high speed when the main contact is opened, which improves insulation recovery characteristics, mechanical strength, etc.
Improves equipment reliability.

■ Arc extinguishing chamber storage container 31 and closing resistance contact storage container 40
Since these are made into separate bodies, it is possible to reduce the outer diameter of the container.

As a result, as shown in FIGS. 4 and 5, when the buffer type gas circuit breaker of this embodiment is incorporated into a gas insulated switchgear, it becomes possible to reduce the phase-to-phase dimension, shorten the busbar length, and Gas-insulated switchgear can be downsized.

■ Since the closing resistance contact storage container is separate from the arc-extinguishing chamber storage container, in places other than railroad circuits that do not require closing resistance contacts, only circuit breakers with main contacts housed in the arc-extinguishing chamber storage container can be used. Since it is only necessary to arrange the gas insulated switchgear, it is possible to reduce the size of the gas insulated switchgear while attempting to share the container.

■ The closing resistor is arranged on the upper part of the closing resistance contact storage container 40, and the operation rod 49 of the movable side electrode 45 of the closing resistance contact is directly connected to the operation cylinder 50, so the structure is simple and reliable. is high.

■ Hydraulic operation cylinders 50.35 are used as the driving sources for the closing resistance contact and the main contact, respectively, and both are connected by hydraulic piping 51, making it easy to control the displacement cylinders, and each contact can be operated at different speeds. It is extremely easy to drive and can be opened and closed at precise timing.

■ If the operating mechanism system for each contact was provided separately, even if there was a defect in one system, only the normal contact would open or close, which could result in the circuit breaker being destroyed. By interlocking the displacement action cylinders, it is possible to eliminate the inconvenience that only one contact is opened and closed.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but can be widely applied to all circuit breakers in which the main contact opening/closing method is a double motion method.

Furthermore, the operation mechanism for the main contact and the closing resistance contact is not limited to hydraulic pressure, but may also use other fluids or mechanical means using links. Furthermore, it is also applicable to a circuit breaker in which a main contact and a closing resistance contact are housed in the same container.

[Effects of the Invention] As described above, according to the present invention, the closing speed of the closing resistance contact is made larger than the relative closing speed of the first and second movable electrodes constituting the main contact, and the closing speed of the main contact is By keeping the closing resistance contact in the open state even when the
A miniaturized buffer type gas circuit breaker can be provided.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the buffer type gas circuit breaker of the present invention, FIG. 2 is a schematic configuration diagram showing an example of the hydraulic operation cylinder for the circuit breaker shown in FIG. 1, and FIG. 3 is the same as that shown in FIG. 1. FIG. 4 is a sectional view showing an embodiment of the closing resistance contact operation cylinder, in which (A) shows the open state, (B) shows the closed state, and FIG. 4 shows the buffer type gas circuit breaker of FIG. A plan view showing the state in which it is incorporated into the device, FIG. 5 is a side view, and FIGS. 6 and 7.
The figures are cross-sectional views showing an example of a conventional double-motion buffer type gas circuit breaker, with FIG. 6 showing the closed state and FIG. 7 showing the open state. Figure 8 is a characteristic diagram showing the insulation recovery characteristics of the main contact and closing resistance contact in a 550KV class single-break circuit breaker and double-break circuit breaker, and Figure 9 is a gas-insulated switchgear using a conventional buffer type gas circuit breaker. FIG. 3 is a plan view showing a problem with the device. 1... First movable electrode, 10... Second movable electrode, 20
...Three-phase-block busbar, 21...Connection busbar, 22...
Disconnector, 23... Circuit breaker, 24... Current transformer, 25.
... Bushing, 30... Arc extinguishing chamber, 31... Arc extinguishing chamber storage container, 32... Opening, 33... Conductor, 34...
...Operation mechanism box, 35...Arc chamber operation cylinder, 36
... Operating rod, 37... Output port, 38... Conductor, 39.41.42... Opening, 40... Closing resistance contact storage container, 43... Closing resistor, 44... ... Closing resistance fixed side electrode, 45 ... Return spring, 46
... Closing resistance contact movable side electrode, 47 ... Sliding part, 4
8... Insulating rod, 49... Operating rod, 50...
- Closing resistance contact operation cylinder, 51... Hydraulic piping, 5
2... Takeout port, 501... Cylinder, 501a. b...liquid chamber, 502...piston, 503...supply valve, 503a, b-...valve chamber, 504-...discharge valve,
504a...valve body, 504b valve lot, 505
a ~ 505C... Spring, 506a, b... Channel,
506c...Low pressure flow path. Figure 2 Figure (Al Figure 3 (8) Figure ■ Figure

Claims (1)

[Scope of Claims] A main contact consisting of a first and a second movable electrode is housed in the arc extinguishing chamber, and in parallel with the main contact, a fixed side electrode, a movable side electrode, and an input terminal connected to these electrodes are arranged. In a buffer type gas circuit breaker with a double-motion single-break closing resistance contact, which is equipped with a closing resistance contact consisting of a resistor, the movable electrode of the closing resistance contact is connected to a resistance contact that interlocks with the main contact operating cylinder. It is driven by an operating cylinder, and the closing speed of the movable electrode of the closing resistance contact section is set to be higher than the relative closing speed of both movable electrodes that constitute the main contact in the arc extinguishing chamber, and after closing the main contact, the closing speed of the movable electrode of the closing resistance contact section is set to be higher than the relative closing speed of both movable electrodes that constitute the main contact in the arc extinguishing chamber. A buffer type gas circuit breaker characterized in that only the opening section performs the opening operation.