JPH11176300A - Puffer gas circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deterioration of arc extinguishing capability due to low density of an arc-extinguishable gas flow in the initial stage of a circuit opening operation by communicating a buffer chamber of a buffer cylinder add the hollow part of a cylinder through a connection hole of the cylinder in a state that a fixed contactor and a movable contact are brought into contact. SOLUTION: A second piston 12 is moved into a fixed piston 8 through an operation rod 13 in a container of a gas circuit breaker filled with an arc- extinguishable gas and a buffer cylinder 7 integrally attached to the tip of the cylinder 17 attached to the piston 12, a movable contact 4, ad an insulated nozzle 2 are moved in the left direction. Consequently, the fixed contactor 1 is moved into the throat of the insulated nozzle 2 to be brought into contact with the movable contactor 4. In such a state, a connection hole 12 formed in the cylinder 17 is communicated with a buffer chamber 5 constituted of the buffer cylinder 7, a piston 8, and the cylinder 17. Consequently, at the time of starting the circuit opening operation, the gas in the buffer chamber 5 is supplied to the cylinder 17 through a hollow part 16 and the density of the arc-extinguishable gas blown through a small hole 14 is prevented from lowering.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a puffer type gas circuit breaker having a suction chamber, and more particularly, to adjusting a gas suction start time at an early stage of an opening operation and a pressure reduction amount of the suction chamber during the opening operation. It relates to a possible puffer type gas circuit breaker.

[0002]

2. Description of the Related Art Along with an increase in power demand and severe land conditions in the center of a city, a breaker provided in a substation is required to have an increased breaking capacity, downsizing, high reliability, and the like. A puffer type gas circuit breaker is equipped with a pair of fixed contacts and movable contacts in a container filled with an arc-extinguishing gas, and an operating rod connected to a puffer cylinder is driven by an actuator to be surrounded by a puffer cylinder and a piston. The compressed puffer chamber volume is reduced, and the arc generated between the fixed contact and the movable contact due to the open circuit is blown with the compressed arc-extinguishing gas in the puffer chamber to extinguish the arc. Therefore, in order to improve the performance of the puffer type gas circuit breaker, it is effective to increase the blowing force of the arc-extinguishing gas.

In order to increase the blowing of the arc-extinguishing gas,
There are methods of improving the gas flow path structure, strengthening the operating force of the operating device for performing the opening operation, and increasing the relative pressure difference between the puffer chamber and the space downstream of the gas flow. Among them, as a technique related to the last method, as described in Japanese Patent Application Laid-Open No. 51-67974, the pressure in the space and the initial pressure in the vessel are reduced with the opening operation on the downstream side of the gas flow from the puffer chamber. There is a puffer type gas circuit breaker with a suction chamber that is lower than the suction chamber.

A conventional example will be described with reference to FIG.
An operating rod 13 connected to an operating device (not shown) is connected to the puffer cylinder 7 and the movable contact 4 via a cylinder 17, and the fixed contact 1 and the movable contact 4 are moved by the operating device 13 in the axial direction. Perform opening and closing operations. On the opening side of the puffer cylinder 7, a piston 8 which is slidably connected to the inner surface of the puffer cylinder 7 is supported by a fixing member (not shown).

The space formed by the puffer cylinder 7, the piston 8 and the cylinder 17 is a puffer chamber 5
Thus, the inner volume of the movable contact 4 is reduced along with the separating operation. Although not shown, since the entire shut-off portion is housed in a container filled with the arc-extinguishing gas, the reduction in the internal volume of the puffer chamber 5 results in the compression of the arc-extinguishing gas. The insulating nozzle 2 is fixed so as to surround the small hole 14 of the puffer cylinder 7, and when the throat portion of the insulating nozzle 2 comes out of the fixed contact 1, the puffer chamber 5 communicates with the surrounding gas through the throat portion. . The aforementioned cylinder 17 has a hollow portion 16.

[0006] A second piston 11 slidable on the inner surface of the supporting cylindrical portion of the piston 8 is connected to the operating rod 13. The suction chamber 6 is formed by the second piston 11, the piston 8, and the cylinder 17. The hollow portion 16 of the cylinder 17 communicates with the suction chamber 6 via the connection hole 12 even in a contact state between the two contacts.
Contrary to the puffer chamber 5, the suction chamber 6 increases in volume in connection with the opening operation of the movable contact 4, and becomes negative with respect to the initial pressure in the container.

The opening operation of the fixed contact 1 and the movable contact 4 is performed by driving the operating rod 13 rightward by the operating device. With this operation, the volume of the puffer chamber 5 is reduced, and the arc-extinguishing gas in the volume is compressed and its pressure is increased. On the other hand, the suction chamber 6 increases its volume. An arc 15 is generated by the opening between the fixed contact 1 and the movable contact 4. At this time, as shown in FIG. 6, a gas flow 3a from the puffer chamber 5 to the suction chamber 6 and a gas flow 3b toward the fixed contact 1 after the fixed contact 1 has passed through the throat portion of the insulating nozzle 2 are arcuated. To extinguish the arc.

FIG. 7 shows the pressure characteristics of each part associated with the above-described opening operation. The vertical axis represents the pressure P, and the horizontal axis represents the time t. P ₀
Is the pressure of the arc-extinguishing gas filled in the container, 18 is the stroke characteristic, 19 is the pressure characteristic of the puffer chamber 5, and 20 is the pressure characteristic of the suction chamber 6. As shown in the figure, the pressure inside the puffer chamber 5 rises slowly, and a sufficient pressure cannot be obtained from the beginning of the opening operation. On the other hand, the suction chamber 6 has a remarkable decrease in pressure from the beginning of the opening operation. For this reason, in the initial stage of the opening operation, a blowing gas flow having a sufficient flow velocity is formed in the gas flow path connecting the puffer chamber 5 and the suction chamber 6. Further, at the end of the opening operation, the piston 8 is provided with an exhaust port 9 to suppress a rise in the pressure of the suction chamber 6, so that the pressure in the suction chamber 6 does not become larger than the initial pressure in the container.

[0009]

In the above conventional example, the effect of the suction chamber 6 enhances the effect of blowing to the arc 15 from the beginning of the opening operation, so that it has excellent performance in large current interruption duty. In the case of interrupting a small current, there is a concern that the shut-off performance may be reduced due to a decrease in gas density due to an increase in the speed of the arc-extinguishing gas flow.

In order to reduce the size of the circuit breaker, the operating force for driving the puffer cylinder 7 must be reduced.
In some cases, a method of adjusting the pressure drop amount of the suction chamber 6 is required.

An object of the present invention is to provide a puffer type gas circuit breaker for solving the above-mentioned problems.

[0012]

In order to achieve the above object, the present invention according to claim 1 comprises a pair of fixed and movable contacts and a puffer cylinder in a container filled with an arc-extinguishing gas. , A puffer chamber composed of a cylinder and a piston, an operating rod connected to the cylinder, and an arc generated between the fixed contact and the movable contact by compressing the arc-extinguishing gas with the opening operation of the puffer cylinder. A puffer-type gas shut-off provided with a hollow part and a connection hole in the cylinder to guide the arc-extinguishing gas blown to the inside of the puffer chamber or the container, and a suction chamber whose internal volume increases with opening operation. A puffer type gas circuit breaker, wherein the connecting hole of the cylinder communicates with the puffer chamber when the fixed contact and the movable contact are in contact with each other. .

According to a second aspect of the present invention, there is provided a puffer type apparatus comprising the suction chamber surrounded by the piston having at least one set of an intake port and an exhaust port. It is a gas circuit breaker.

That is, when the fixed contact 1 and the movable contact 4 are in contact with each other, the connecting hole 12 of the cylinder 17 is communicated with the puffer chamber 5 so that the opening operation of the fixed contact 1 and the movable contact 4 is started. Since there is no suction of the arc-extinguishing gas from the hollow portion 16 into the suction chamber 6 at the time of the opening, the arc-extinguishing gas flow which becomes a problem when the gap between the fixed contact 1 and the movable contact 4 is short during the opening operation is short. It is possible to reduce a decrease in gas density due to an increase in speed.

By forming the suction chamber 6 with the piston 8 having at least one set of the intake port 21 and the exhaust port 9, the inside of the container is maintained until the suction chamber 6 and the cylinder 17 communicate with each other through the communication hole 12. , The arc-extinguishing gas can be guided to the suction chamber 6, and it is possible to prevent a pressure drop in the suction chamber 6 during this time. Further, the arc-extinguishing gas in the suction chamber 6 can be exhausted from the exhaust port 9 at the end of the opening operation.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1, 2, 3, 4, and 5. FIG.

FIG. 1 is a longitudinal sectional view of a puffer type gas circuit breaker in a closed state according to a first embodiment of the present invention. Although not shown, the entire blocking unit is housed in a container filled with an arc-extinguishing gas. The operating rod 13 is connected to an operating device (not shown), and is connected to the puffer cylinder 7 and the movable contact 4 via a cylinder 17. The opening operation is performed by an operating device (not shown) using an operating device (not shown).
3 to the right. The piston 8 is supported by a fixed member (not shown) and has a slidable relationship with the inner surface of the puffer cylinder 7. The space formed by the puffer cylinder 7, the piston 8, and the cylinder 17 is the puffer chamber 5, and the inner volume of the puffer chamber 5 is reduced with the opening operation, and the arc-extinguishing gas is compressed.

The insulating nozzle 2 is fixed so as to surround the small hole 14 of the puffer cylinder 7, and when the throat portion of the insulating nozzle 2 comes out of the fixed contact 1, the puffer chamber 5
Communicates with the surrounding gas through the throat portion. The cylinder 17 has a hollow portion 16, and a part of the arc-extinguishing gas blown out from the puffer chamber 5 between the fixed contact 1 and the movable contact 4 flows into the hollow portion 16.

Further, a second piston 11 slidable on the inner surface of the supporting cylindrical portion of the piston 8 is connected to the operating rod 13. The suction chamber 6 is formed by the second piston 11, the piston 8, and the cylinder 17. In the contact state between the two contacts, the hollow portion 16 of the cylinder 17 is disposed so as to communicate with the puffer chamber 5 via the communication hole 12. According to this embodiment, the suction of the arc-extinguishing gas into the suction chamber 6 can be prevented at the beginning of the opening operation.

FIG. 2 is a longitudinal sectional view of a puffer type gas circuit breaker at an early stage of an opening operation according to a second embodiment of the present invention. In a contact state between the fixed contact 1 and the movable contact 4, the hollow portion 16 of the cylinder 17 is
It communicates with the puffer room 5. The operating rod 13 has a second piston 1 slidable on the inner surface of the supporting cylindrical portion of the piston 8.
1 are connected. The suction chamber 6 is formed by the second piston 11, the piston 8, and the cylinder 17.

The piston 8 is slidable with respect to the inside of the puffer cylinder 7 and the cylinder 17. In this figure, a communication hole 10 is formed in a puffer cylinder 7 and a piston 8 is formed.
Further, an exhaust port 9 and an intake port 21 are provided. According to the present embodiment, during the opening operation, the suction chamber 6 is disconnected from the cylinder 17 through the communication hole 10 through the communication hole 10 of the puffer cylinder 7 until the suction chamber 6 and the cylinder 17 communicate with each other through the connection hole 12. The arc gas is led to the suction chamber 6
Can be prevented from lowering.

FIG. 3 shows the puffer type gas circuit breaker shown in FIG. In the middle stage of the opening operation, the communication hole 10 of the puffer cylinder 7 is closed by the piston 8, and the pressure in the suction chamber 6 decreases as the internal volume increases. Further, at the end of the opening operation, the exhaust port 9 of the piston 8 and the puffer cylinder 7
The communication holes 10 communicate with each other, and the pressure increase in the suction chamber 6 can be suppressed.

FIG. 4 is a longitudinal sectional view of a puffer type gas circuit breaker in the middle of an opening operation according to a third embodiment of the present invention. In a contact state between the fixed contact 1 and the movable contact 4, the hollow portion 16 of the cylinder 17 is
It communicates with the puffer room 5. The operating rod 13 has a second piston 1 slidable on the inner surface of the supporting cylindrical portion of the piston 8.
1 are connected. The suction chamber 6 is formed by the second piston 11, the piston 8, and the cylinder 17.

The piston 8 is slidable with respect to the inside of the puffer cylinder 7 and the cylinder 17. In this figure, the piston 8 has an exhaust port 9 and an intake port 21. Even in such a structure, as in the second embodiment, the suction chamber 6 and the cylinder 17 during the opening operation are connected to the connection hole 12.
Until the point of communication through the, the arc-extinguishing gas is guided into the suction chamber 6 from inside the container (not shown), and the pressure in the suction chamber 6 can be prevented from lowering.

FIG. 5 is a longitudinal sectional view of a puffer type gas circuit breaker in the middle of an opening operation according to a fourth embodiment of the present invention. In a contact state between the fixed contact 1 and the movable contact 4, the hollow portion 16 of the cylinder 17 is
It communicates with the puffer room 5. The piston 8 is provided with an exhaust port 9 and an intake port 21. In this figure, the puffer cylinder 7 is provided with a closing plate 22 at one end, and the suction chamber 6 is constituted by the closing plate 22, the puffer cylinder 7, the cylinder 17 and the piston 8 slidable with respect to these. ing. Even in such a structure, as in the second embodiment, the suction chamber 6 is connected to the suction chamber 6 from the container (not shown) until the suction chamber 6 and the cylinder 17 communicate with each other through the connection hole 12 during the opening operation. It is possible to prevent the gas from being introduced and the pressure in the suction chamber 6 from decreasing.

[0026]

According to the present invention, when the fixed contact and the movable contact are in contact with each other, the connection hole of the cylinder is communicated with the puffer chamber, so that the high-temperature gas in the suction chamber from the middle stage to the late stage of the opening operation is excellent. Therefore, it is possible to prevent a decrease in the shutoff performance in the early stage of the opening operation without impairing the cooling effect of the PGA, so that there is an effect that the shutoff performance can be improved when the puffer type gas circuit breaker is downsized and the capacity is increased.

By forming the suction chamber with a piston having an intake port and an exhaust port, the arc-extinguishing gas is introduced from the container to the suction chamber until the connecting hole of the cylinder communicates with the suction chamber during the opening operation. On the other hand, since it is possible to prevent the pressure in the suction chamber from dropping, the operating force for driving the puffer cylinder is reduced, and the puffer type gas circuit breaker can be downsized.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a puffer type gas circuit breaker according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a puffer type gas circuit breaker at an early stage of an opening operation, which is another embodiment of the present invention.

FIG. 3 is a longitudinal sectional view of the puffer circuit breaker shown in FIG. 2 in a middle stage of an opening operation.

FIG. 4 is a longitudinal sectional view of a puffer type gas circuit breaker at an early stage of an opening operation according to another embodiment of the present invention.

FIG. 5 is a longitudinal sectional view of a puffer type gas circuit breaker at an early stage of an opening operation, which is another embodiment of the present invention.

FIG. 6 is a longitudinal sectional view showing a conventional example of a puffer type gas circuit breaker having a suction chamber.

FIG. 7 is a pressure characteristic diagram of each part in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fixed contact, 2 ... Insulating nozzle, 3a, 3b ... Gas flow, 4 ... Movable contact, 5 ... Puffer chamber, 6 ... Suction chamber, 7 ... Puffer cylinder, 8 ... Piston, 9 ... Exhaust port 10, 12 ... communication hole, 11 ... second piston, 13 ...
Operation rod, 14: small hole, 15: arc, 16: hollow portion, 17: cylinder, 21: intake port, 22: closing plate.

Claims (2)

[Claims] A pair of fixed and movable contacts in a container filled with an arc-extinguishing gas, a puffer chamber comprising a puffer cylinder, a cylinder and a piston, an operation rod connected to the cylinder, In order to guide the arc-extinguishing gas blown to the arc generated between the fixed contact and the movable contact by compressing the arc-extinguishing gas along with the opening operation of the puffer cylinder into the puffer chamber or the container. In a puffer-type gas circuit breaker provided with a hollow portion and a connection hole in the cylinder and having a suction chamber whose internal volume increases with the opening operation, the cylinder may be mounted in a state where the fixed contact and the movable contact are in contact with each other. Wherein the connection hole communicates with the puffer chamber. 2. A fixed contact and a movable contact forming a pair in a container filled with an arc-extinguishing gas, a puffer chamber comprising a puffer cylinder, a cylinder and a piston, an operating rod connected to the cylinder, In order to guide the arc-extinguishing gas blown to the arc generated between the fixed contact and the movable contact by compressing the arc-extinguishing gas along with the opening operation of the puffer cylinder into the puffer chamber or the container. In a puffer type gas circuit breaker having a hollow portion and a connecting hole in the cylinder and having a suction chamber whose internal volume increases with the opening operation, the suction surrounded by the piston having at least one set of an intake port and an exhaust port. A puffer type gas circuit breaker characterized by having a chamber.