JPS6196623A - Gas breaker - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a gas circuit breaker with improved arc extinguishing chamber and improved interrupting performance.

[Technical background of the invention and its problems]

As the capacity of power transmission systems increases, the breaking capacity required of circuit breakers used in substations and switchyards continues to increase. Therefore, it is necessary to increase the breaking capacity per breaking point.

Buffer-type SFs and gas circuit breakers are mainly used in substations and switching stations where the power transmission voltage is relatively high. This is 8F,
This is due to its excellent gas interrupting performance and insulation performance, and the buffer type is particularly simple in structure compared to the two-pressure type, so it has become the mainstream of high-voltage circuit breakers. In addition, it is particularly often used in closed type gas switchyards where the entire substation equipment is insulated with 8F6 gas, as it has great advantages in insulation coordination with other equipment, equipment placement, etc.

FIG. 8 shows an arc extinguishing chamber of a conventional buffer type gas circuit breaker.

A gas having good arc-extinguishing properties and insulation properties, such as SF or gas, is sealed in a container (not shown), and the arc-extinguishing chamber shown in FIG. 8 is housed in the container. The buffer piston 3 is fixed to a container (not shown) via an insulator, and a back cylinder 2 that slides on the outer periphery of the buffer piston 3 is arranged coaxially around the buffer piston 3. The buffer cylinder 2 is fixed to one end of an operating rod 6 that slidably passes through the inner circumferential surface of the buffer piston 3. The other end of the operating rod 6 is connected to an operating mechanism (not shown). A movable electrode 1 is fixed to one end of the operating rod. The operating rod 6 is reciprocated by an operating mechanism (not shown). Along with this, the movable electrode 1 performs mechanical and electrical opening and closing between the movable electrode 1 and the fixed electrode 5 disposed inside. In addition, the buffer cylinder (2) generates compressed gas by relative movement with the buffer piston 3, extends this compressed gas around the movable electrode 1, and insulates the nozzle 4 fixed to the buffer cylinder 2.
Blow out through the gas to create a high-speed gas flow. This insulating nozzle 4 has a throat portion 4a with the smallest diameter on the fixed electrode 5 side. When interrupting the current, a high-speed gas flow is blown onto the arc 7 generated between the fixed and movable electrodes 4.5 to interrupt the current.

The breaking performance of the buffer type gas circuit breaker configured in this manner is determined by the volume of the buffer cylinder, and the volume of the buffer cylinder 2 is increased to improve performance. However, as the volume of the back cylinder 2 increases, the force for moving the buffer cylinder 2, that is, the operating force of the operating mechanism connected to the operating rod 6 to which the buffer cylinder 2 is attached must be increased.

Therefore, there was a drawback that the size of the operating mechanism became large and the entire circuit breaker became large.

[Purpose of the invention]

The present invention has been made in consideration of the above points, and provides a small, lightweight, and highly reliable gas circuit breaker that efficiently uses the thermal energy of the arc itself and compressed gas in the buffer chamber for arc extinguishing action. The purpose is to

[Summary of the invention]

In order to achieve the above object, in the present invention, the cylinder forming the buffer chamber opens into the buffer chamber when charging,
A groove longer than the thickness of the piston is provided in the direction of movement of the piston, and the insulating nozzle is provided with a groove that connects the flow path formed by the buffer chamber, the movable electrode, and the insulating nozzle only when the insulating nozzle engages with the groove during the shutoff operation. Since the holes are provided so as to communicate with each other, at the time of shutoff, the insulating gas in the flow path can be made to have a high pressure by the thermal energy of the arc, and the insulating gas in the pump chamber can be compressed by the piston and then blown onto the arc.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to FIGS. 1 to 6. The arc extinguishing chamber, which is fixed inside a container (not shown) filled with insulating gas, has the following configuration. Disposed on the left side of the figure are a fixed current-carrying electrode 10 formed into a cylindrical shape and a fixed arc electrode 11 electrically connected to the central axis of the fixed current-carrying electrode 10. On the other hand, on the right side is an operating rod 12 connected to an operating device (not shown) via an insulating rod.
A movable current-carrying electrode 14 and a movable arc electric fence 15 are mounted on the fixed current-carrying electrode 10 side of the operating rod 12 via a buffer piston 13 and operate together with the operating rod 12. The buffer piston 13 has a disc shape,
It is fixed to one end of the operating rod 12. Movable arc electrode, 1
5 is a cylindrical counter-operating rod 1 of the buffer piston 13;
The fixed arc electrode 11 is fixed approximately at the center of the second side and is aligned with the axis of the fixed arc electrode 11. In addition, the movable current-carrying electrode 14
The counter operation rod 12 of the buffer piston 13 is cylindrical.
It is arranged and fixed on the side and outside of the movable arc electrode 15 and aligned with the axis of the fixed current-carrying electrode 10 . When the circuit breaker is closed, the fixed current-carrying electrode 1 is connected as shown in Figure 1.
The movable current-carrying electrode 14 fits into the movable arc electrode 15.
A fixed arc electrode 11 is fitted inside. A buffer cylinder 16 is arranged around the outer periphery of the buffer piston 13, into which the buffer piston 13 and the movable current-carrying electrode 14 are slidably fitted. Furthermore, the buffer cylinder 16
(7) A fixed piston 17 is airtightly provided inside and at a position facing the buffer piston 13, and the fixed piston 17, the buffer piston 13 and the buffer cylinder 1
A buffer chamber 18 is configured in the space surrounded by 6. A cylindrical insulating nozzle 19 is provided on the inner surface of the movable current-carrying electrode 14, one end of which is brought into contact with and supported by the end face of the reparation piston 13 by the movable current-carrying electrode 14, and the other end of which extends near the outer peripheral end of the fixed arc electrode 11. will be established. Note that the insulating nozzle 19 is arranged outside the movable arc electrode 15 at a predetermined interval.

The buffer cylinder 16 will now be described in detail with reference to FIGS. 4 and 5. Four grooves 16a are provided on the inner surface of the buffer cylinder 16, which are equally spaced and open to the buffer chamber 18. This groove 16a is arranged near the fixed piston 17, that is, at a position separated from the fixed piston 17 by about 10% to 50% of the stroke of the puffer piston 13 on the fixed current-carrying electrode 10 side. Further, the axial length of the groove 16g of the back cylinder 16 is several times the thickness of the buffer piston 13,
To prevent the buffer piston 13 from always blocking the groove 16a. Furthermore, the fixed piston 17 in the groove 16a
The side cross section is sloped smoothly so that the cross-sectional area of the groove 16a gradually decreases toward the fixed piston 17.

Next, the movable current-carrying electrode 14 and the insulating nozzle 19 will be described in detail with reference to FIG. The insulated nozzle 19 is connected to the movable current-carrying electrode 14
The buffer piston 13 is fixed to the buffer piston 13 together with the movable current-carrying electrode 14 by being fitted and integrated with the inner surface of the buffer piston 13 . Near the buffer piston 13 side of the movable current-carrying electrode 14 and the insulating nozzle 19,
The holes 14a and 19a, which smoothly communicate between the outer circumferential surface of the movable current-carrying electrode 14 and the inner circumferential surface of the insulating nozzle 19, are equally spaced in four holes.
There are designated areas. This hole! 4a and 19M are inclined so as to approach the fixed arc electrode 11 side from the outer peripheral surface of the movable current-carrying electrode 14 toward the inner peripheral surface of the insulating nozzle 19.

In the closed state of the circuit breaker shown in FIG.
The outer periphery of the hole 14a is closed by the inner peripheral surface of the back cylinder 16, and in the state shown in FIG. communicate with. In addition, hole 14
a, 19a are arranged on a common radius with respect to the groove 16a. Further, the sliding movement with respect to the back cylinder 16 is performed on the side of the fixed current-carrying electrode 10 from the hole 14a of the buffer piston 13 and the movable current-carrying electrode 14.

The operation of the configuration of this embodiment will be explained below.

In the circuit breaker closing state shown in FIG.
By holding the movable current-carrying electrode 14 to the left in the figure, the movable current-carrying electrode 14 contacts the inside of the fixed current-carrying electrode 10, and the movable arc electrode 15 contacts the outside of the fixed arc electrode 11.

As a result, main current conduction is performed between the movable current-carrying electrode 14 and the fixed current-carrying electrode 10. In addition, the buffer piston 13
is located closer to the fixed arc electrode 11 than the groove 16a, and the buffer chamber 18 surrounded by the buffer piston 13, the fixed piston 17, and the buffer cylinder 16 is filled with an arc-extinguishing insulating gas, such as 8F gas.

At this time, the buffer chamber 18 is kept sufficiently airtight. Note that the buffer piston 1 constituting the buffer chamber 18
3. The fixed piston 17 or the pack cylinder 16 is provided with a known check valve (not shown).

This check valve allows insulating gas to flow into the buffer chamber 18 through the check valve, and prevents the insulating gas from flowing out of the buffer chamber 18.

Now, the operating rod 12 moves toward the fixed piston 17 in response to a tripping command for the circuit breaker. At the same time buffer piston 1
3 moves to the right while compressing the insulating gas in the sealed buffer chamber 18. Moreover, the movable current-carrying electrode 14 is separated from the fixed current-carrying electrode 10, and the current is applied to the fixed and movable arc electrodes 11.1.
It is held for 5 minutes. Subsequently, the movable arc electrode 15 separates from the fixed arc electrode 11, so that both arc electrodes 1
An arc 20 occurs during 5.11. The energy accompanying the generation of the arc 20 increases the pressure of the insulating gas within the flow path 21 formed between the insulating nozzle 19 and the movable arc electrode 15. That is, the flow path 21 has an open portion at the throat portion 19b and hole 19a formed at the end of the insulating nozzle 19, but the hole 19a is closed by the buffer cylinder 16 together with the hole 14a of the movable current-carrying electrode 14. . Further, since the throat portion 19b surrounds the outside of the arc 20, the insulating gas in the throat portion 19b expands due to the heat of the arc 20, and as a result, the throat portion 19 is closed due to a so-called blocking phenomenon. Therefore, the insulating gas in the flow path 21 is compressed and the pressure increases. Further, when the buffer piston 13 moves to the right by a predetermined distance suitable for interrupting the arc 20, the hole 1 of the movable current-carrying electrode 14
4a and the hole 19a of the insulating nozzle 19 engage with the groove 168 of the buffer cylinder 16. That is, when the buffer piston 13 reaches the middle part of the groove 16a as shown in FIG.
, 19a. Therefore, the high-pressure insulating gas in the buffer chamber 18 flows through the grooves 16a and holes 14a.

It is instantaneously discharged through the insulating nozzle 19 and the movable arc electrode 15 into the flow path 21 through the insulating nozzle 19a. As a result, the pressure of the insulating gas in the flow path 21 is increased by the arc 20, and the pressure is further increased by the insulating gas discharged from the buffer chamber 18. This insulating gas is squeezed by the throat portion 19b of the insulating nozzle 19 and then blown onto the arc 20 at high speed to extinguish the arc. Further, as shown in FIG. 3, the buffer piston 13 moves to the right and reaches between the groove 16a of the buffer cylinder 16 and the fixed piston 17. At this time, the buffer chamber 18 is sealed again and the insulation inside the buffer chamber 18 is closed. The gas is compressed and pressurized, and the buffer piston 1
You can gradually slow down the rightward movement speed of 3. That is, it can be buffered.

In this embodiment, the buffer piston 13 that fixes the movable 4J 7M pole 14, the movable arc electrode 15, etc. is slidably arranged in the buffer cylinder 16 to constitute the buffer chamber 18. The insulating gas within 18 is effectively compressed to high pressure. Furthermore, since M 16a having an axial length several times the thickness of the buffer piston 13 is provided on the inner surface of the buffer cylinder 16 and on the side of the tripping end position of the buffer piston 13, the buffer chamber
The high pressure insulating gas in the buffer chamber 8 flows through the groove 16a to the buffer chamber 1.
8 and the inside of the buffer chamber 18 is depressurized. The cross section of this groove 16H on the fixed piston 17 side is sloped, and the end of this groove 16a is connected from the fixed piston 17 to the buffer piston 1.
About 10% of the stroke of No. 3 is provided on the fixed current-carrying electrode 10 side. Therefore, when the buffer piston 13 reaches about 10% of the stroke between the groove 16a and the fixed piston 17 near the end position of the tripping operation of the buffer piston 13, that is, when the buffer piston 13 reaches about 10% of the stroke between the groove 16a and the fixed piston 17.
The buffer chamber 18 is gradually sealed again and the buffer chamber 18
As the pressure of the insulating gas inside increases gradually, the buffer piston 1
3 has an effective buffering effect without colliding with the stationary piston 17 so that the receiver stops quietly. Furthermore, the movable current-carrying electrode 14 and the buffer piston 13 of the insulating nozzle 19
Holes 14a and 19a are provided nearby to smoothly communicate the outside of the movable energized electrode 14 and the inside of the insulating nozzle 19, so that when the buffer piston 13 passes through the position a16H, the high pressure inside the buffer chamber 18 is reduced. The insulating gas instantly flows into flow path 2.
1 is released. Furthermore, since the hole 14a is closed by the buffer cylinder 16 until it reaches the position of the groove 16a, the insulating gas in the flow path 21 becomes high pressure due to the thermal energy accompanying the generation of the arc 20. Therefore, the arc 20 can be effectively extinguished by spraying the insulating gas which has been compressed in the buffer chamber 18 to a high pressure using the so-called expansion method and the high-pressure insulating gas using the so-called self-blade arc extinguishing method using the arc 20. can. Along with this,
The operating force for the circuit breaker can be reduced, and the circuit breaker can be made small and lightweight. Moreover, the fixed piston 17 side section of the groove 16a is sloped, and the holes 14a and 19M
is inclined toward the fixed arc electrode 11 from the outside toward the inside, so that the insulating gas compressed to high pressure within the buffer chamber 18 smoothly flows through the grooves 16a, holes 14a, and 19R. It can be discharged into the flow path 21.

In addition, in this embodiment, the groove 16a and the hole 14a, 1
Although 9a are provided at four locations, the number is not limited to four locations. Furthermore, even in a configuration in which both current-carrying electrodes 10.14 are omitted, great effects can be achieved.

In addition, as shown in FIG. 7, by increasing the volume of the flow path 21 formed between the movable arc electric core 15 and the insulating nozzle 19 and making it equal to or larger than the volume of the buffer chamber 18, the inside of the flow path 21 can be increased. A large amount of insulating gas can be pressurized by the arc 20.

〔Effect of the invention〕

As explained above, according to the present invention, the cylinder is provided with a groove that opens into the buffer chamber at the time of charging and is longer than the thickness of the piston in the direction of movement of the piston, and the insulating nozzle is provided with a groove that is buffered only when the groove is engaged with the groove during the shutoff operation. Since a hole is provided that communicates between the chamber and the flow path via a groove, the insulating gas in the flow path is made into high-pressure gas by an arc, and the insulating gas in the puffer chamber is made into high-pressure gas by a piston, and both of these insulating gases are By simultaneously spraying the gas on the arc, the arc extinguishing ability can be improved and a small and lightweight gas circuit breaker can be obtained.

[Brief explanation of the drawing]

1 to 3 show one embodiment of the present invention, and FIG. 4 is a sectional view of an arc extinguishing chamber of a circuit breaker, and FIG. 4 is a movable section shown in FIGS. 7 is a sectional view of the arc extinguishing chamber of a gas circuit breaker according to another embodiment of the present invention; FIG. 8 is a sectional view of the arc extinguishing chamber of a conventional gas circuit breaker. It is. 10... Fixed current-carrying electrode, 11... Fixed arc electrode,
12... Operating rod, 13... Buffer piston,
14... Movable current-carrying electrode, 14a... Hole, 15...
Movable arc electrode, 16...buffer cylinder, 16a...groove, 17.
...Fixed piston, 18...Buffer chamber, 19...
Insulating nozzle, 19a...hole, 19b...stroke portion, 20...arc, 21...flow path.

Claims (1)

[Claims] a fixed side electrode, a movable side electrode disposed opposite to the fixed side electrode so as to be able to move toward and away from the fixed side electrode, a piston that supports the movable side electrode and operates integrally with the movable side electrode, and one end of the movable side electrode is connected to the movable side of the piston. an operating rod fixed to the opposite side of the electrode; a cylinder slidably surrounding the piston; an insulator that forms a flow path between a fixed piston forming a buffer chamber and the movable electrode so as to surround it, supports the piston at one end, and extends the other end toward the fixed electrode. A nozzle is provided in a predetermined part of the cylinder, and a groove is provided in a predetermined part of the cylinder that opens toward the piston side of the buffer chamber when the cylinder is turned on and is longer than the thickness of the piston in the direction of movement of the piston, and the insulating nozzle has a groove that is longer than the thickness of the piston when the cylinder is turned on. A gas circuit breaker characterized in that a hole is provided that engages with the groove as the piston moves and communicates between the buffer chamber and the flow path via the groove.