JPH02129821A - Buffer type gas insulated circuit breaker - Google Patents

Abstract

PURPOSE:To make it possible to extinguish an arc in a short time, increase an insulating recovery characteristic between electrodes with compressed gas in a buffer chamber thereafter, also make it possible to shorten a distance between the electrodes by suddenly increasing the pressure of an insulating gas with the heat of an arc produced between a fixed and a movable arcing contacts, and blowing the gas to the arc. CONSTITUTION:The temperature and the pressure of a gas is increased by transferring the heat of an arc 19 produced between a fixed and a movable contacts 4 and 7 when a driving rod 8 is driven in the right direction from its thrown-in state, to the inside of a hot gas chamber 21a through the first discharge path 12a. The pressure of the gas near the hole 11 is decreased with the extruction of the contact 4 from the insertion through hole 11, and the high pressurized gas in the chamber 21 is blown to the arc 19 through the discharge path 12a for extinguishing the arc. At this juncture, the second discharge path 12b is make narrower in comparison with the discharge path 12a so as to decrease the transfer of the heat of the arc 19 to a buffer chamber 9 to prevent the increase of the pressure in the chamber 9 thus reducing energy for operation of the rod 8. In this way, when a buffer cylinder 10 is shifted in the left direction, the pressure inside the chamber 9 becomes negative thus the rod 8 is replaced to its thrown-in state.

Description

Detailed Description of the Invention A. Industrial Field of Application The present invention relates to the structure of a buffer type gas circuit breaker. In a buffer-type gas circuit breaker that extinguishes an arc by blowing gas onto the arc, a hot gas chamber is provided within the buffer chamber, and a second discharge path that directly leads the insulating gas from the buffer chamber to the insertion hole is connected to the insulating gas from the hot gas chamber. By making the insulating gas in the hot gas chamber narrower than the first discharge path that leads directly to the vicinity of the insertion hole and by providing a pressure regulating valve between the hot gas chamber and the buffer chamber, the pressure of the insulating gas in the hot gas chamber increases due to the arc energy during opening. is blown onto the arc and extinguishes it reliably, while the heat of the arc is not transferred into the buffer chamber, preventing the generation of drive resistance due to the pressure increase in the buffer chamber, and furthermore moves the insulating gas to the buffer chamber. This prevents the risk of pressure rise in the hot gas chamber without wasting insulating gas.

C1 Conventional technology A buffer type gas circuit breaker is used as a power circuit breaker.

The structure of a conventional buffer type gas circuit breaker is shown in FIG. As shown in the figure, the buffer type gas circuit breaker is composed of a fixed unit 1 and a movable unit 2. The fixed unit 1 is composed of a hollow fixed main contact 3 and a fixed arcing contact 4 provided at the center inside thereof.

On the other hand, the movable unit 2 has a hollow part 5 and a communication hole 6, and a drive rod 8 whose tip part becomes a movable arcing contact 7 and is driven in the left-right direction in the figure, and a drive rod 8 that is fitted on the outside of the drive rod 8 and driven. A buffer cylinder 10 that forms a buffer chamber 9 between it and the rod 8, and an insertion hole that is fixed to the buffer cylinder IO so as to cover the movable arcing contact 7 and that allows the fixed arcing contact 4 to be inserted airtightly at the tip end thereof. an insulating nozzle 13 having a diameter of 1.1 mm and forming a discharge path 12 between it and the drive rod 8, a movable main contact 14 fixed to the outside of the insulating nozzle 13, and a hollow rod 16 having an exhaust hole 15.
A ring-shaped ring is attached to a fixed part (not shown) via a ring and is slidably provided between the drive rod 8 and the buffer cylinder lO, and serves as a suction/exhaust means for sucking in and discharging insulating gas into the buffer chamber 9. It is composed of a piston 17. The reason why the contacts are divided into main contacts and arcing contacts is to distribute the functions so that they can be used properly. Note that 18 is a sealing material. Each unit is provided in an insulating gas such as SF or gas, and constitutes a buffer type gas circuit breaker.

In such a buffer type gas circuit breaker, the drive rod 8
When the drive rod 8 is driven to the left in the figure and is inserted, insulating gas is sucked into the buffer chamber 9 from the insertion hole 11, and when the drive rod 8 is driven to the right in the figure to shut off, the insulating gas is drawn into the buffer chamber 9. of insulating gas is discharged from the discharge path 12 as shown in FIG. The insulating gas is blown onto the arc 19 generated between the fixed arcing contact 4 and the movable arcing contact 7 to extinguish it, and is then discharged through the insertion hole 11 or the communication hole 6 and the exhaust hole I5. Drive rod 8
The driving speed of is generally 8-10 m/s.

D1 Problem to be Solved by the Invention However, as power systems become larger in capacity, buffer-type gas circuit breakers are required to have larger power per interrupt and higher interrupting current. Type gas circuit breakers have the following issues.

(b) In order to improve the interrupting performance, it is necessary to increase the pressure in the buffer chamber and blow high-pressure insulating gas until the arc is extinguished. For this purpose, a buffer cylinder with a large outer diameter and length is used. It is necessary to drive the drive rod at high speed with a large stroke, but this not only increases the size of the buffer cylinder, but also requires a drive means with a large driving force, which increases the size of the drive means and requires a large amount of drive energy. . Therefore, the cost becomes high.

(b) On the other hand, if the drive rod is driven at high speed, the circuit breaker becomes large and heavy, which reduces the reliability of the mechanical structure and operating parts.

Therefore, an object of the present invention is to provide a buffer type gas circuit breaker that solves the above problems.

Means for Solving Problem E1 The structure of the present invention for achieving the above object is to fix a fixed arcing contact in an insulating gas, and at the same time to attach a drive rod formed hollow near the tip of the fixed arcing contact. The tip of the drive rod is provided so that it can be driven along the axis, and a fixed arcing contact can be inserted and removed at will. By providing an insulating nozzle having an insertion hole through which the arcing contact is hermetically inserted so as to cover the movable arcing contact,
In a buffer type gas circuit breaker, a discharge path extending from the buffer chamber to the vicinity of the insertion hole is formed between a movable arcing contact and an insulating nozzle, and a suction/exhaust means for sucking in and discharging insulating gas into the buffer chamber is provided. By forming a hot gas chamber in the buffer chamber and providing a substantially cylindrical separator between the insulating nozzle and the movable arcing contact, a first discharge path and a buffer chamber are formed to guide the insulating gas in the hot gas chamber to the vicinity of the insertion hole. The insulating gas is divided into a second discharge path leading to the vicinity of the insertion hole, the second discharge path is made narrower than the first discharge path, and a pressure regulating valve is provided between the hot gas chamber and the buffer chamber. shall be.

21 When the action is interrupted, an arc is generated between the fixed arcing contact and the movable arcing contact, and the temperature of the insulating gas in the vicinity of the arc increases. This heat is transmitted from the first and second discharge paths to the hot gas chamber and the buffer chamber, but because the second discharge path is narrow, a large amount of heat is transmitted only to the hot gas chamber, and the insulating gas in the hot gas chamber becomes under high pressure. After that, when the fixed arcing contact comes out of the insertion hole and the pressure near the insertion hole decreases, the insulating gas in the hot gas chamber is blown onto the arc and extinguishes it.

While the insulating gas in the hot gas chamber whose pressure increases due to the arc is efficiently used, the pressure increase of the insulating gas in the buffer chamber which is applied as a resistance force to the driving of the suction/exhaust means can be minimized.

When the pressure in the hot gas chamber becomes greater than a predetermined value due to the occurrence of an arc during the interruption, the pressure regulating valve opens and a portion of the insulating gas is released into the buffer chamber. Therefore, safety is ensured without wasting insulating gas.

G. Examples Hereinafter, the present invention will be explained in detail based on examples shown in the drawings. Note that this embodiment is a partial improvement of the conventional buffer type gas circuit breaker, so the same parts as the conventional one are given the same reference numerals and explanations are omitted, and only the different parts will be explained.

(a) Structure of Embodiment The structure of a buffer type gas circuit breaker according to the present invention will be explained based on FIG. 1.

As shown in FIG. 1, inside the conventional buffer chamber 9, there is a ring-shaped first partition wall 20a integrated with the buffer cylinder 10, and a cylindrical first partition wall 20a whose base end is integrally connected to the first partition wall 20a. Two partition walls 20b are provided, and a hot gas chamber 21 is formed in a portion surrounded by the buffer cylinder 10, the first partition wall 20a, and the second partition wall 20b. And insulation nozzle 1
A cylindrical separator 22 made of an insulating material is disposed between the movable arcing contact 7 and the separator 2.
The base end portion of the second partition wall 20b is coupled to the tip end of the second partition wall 20b. As a result, a first discharge path 12a is formed between the insulating nozzle 13 and the separator 22, which communicates the hot gas chamber 21 with the vicinity of the insertion hole 11, and a buffer is formed between the separator 22 and the movable arcing contact 7. A second discharge path 12b is formed that communicates the chamber 9 with the vicinity of the insertion hole 11. The second discharge path 12b is set to be sufficiently narrower than the first discharge path 12a.

A pressure regulating valve 26 is provided between the hot gas chamber 21 and the buffer chamber 9 in the buffer cylinder IO. The pressure regulating valve 26 has a valve body 2 inserted into a pressure relief hole 23 formed in the first partition wall 20a.
7, and a stopper 2 fixed to the tip of the rod portion of the valve body 27.
8 and a spring 29 interposed between the stopper 28 and the first partition wall 20a.

The piston 17 has an intake hole 24 and a check valve 25 so that insulating gas can flow only from the outside to the inside of the buffer chamber 9.
There are multiple.

(b) Operation of the embodiment Next, the operation of the buffer type gas circuit breaker will be explained based on FIGS. 1 to 3.

When the drive rod 8 is driven to the right in the figure from the state shown in FIG. 1 when it is turned on, an arc 19 is generated between the fixed arcing contact 4 and the movable arcing contact 7 as shown in FIG. 19 is transferred into the hot gas chamber 21 through the first discharge path 12a, increasing the temperature and pressure of the insulating gas within the hot gas chamber 21. Then, as shown in FIG. 3, when the fixed arcing contact 4 comes out of the insertion hole I+ and the pressure in the vicinity of the insertion hole 11 decreases, the high pressure insulating gas in the hot gas chamber 2 is released into the first discharge path 12a.
It is blown onto the arc 19 and extinguished it.

At this time, the second discharge path 12b is larger than the first discharge path 12a.
Since the arc 19 is narrow, the heat of the arc 19 is not much transferred to the buffer chamber 9, and the pressure of the insulating gas in the buffer chamber 9 hardly increases. Therefore, less drive energy is required to operate the drive rod 8.

When the interrupting current is small, the pressure in the hot gas chamber 21 does not increase much, but the insulating gas pushed out from the buffer chamber 9 is released through the narrow second release path +2b, so the release rate is high, and in this case It also has great arc extinguishing ability.

When the arc 19 is generated and the pressure in the hot gas chamber 21 increases, if the pressure in the hot gas chamber 21 becomes too large, the pressure regulating valve 26 is activated. In other words, when the force of the insulating gas that tries to push the valve body 27 into the buffer chamber 9 becomes larger than the force of the spring 29 that tries to block the pressure release hole 23 with the valve body 27, as shown in FIG. The pressure regulating valve 26 opens and a portion of the insulating gas is released into the buffer chamber 9. Then, the pressure regulating valve 26 is closed in a state where the force of the insulating gas and the force of the spring 29 are balanced. Therefore, the pressure inside the hot gas chamber 21 does not exceed a predetermined value, which is safe, and since the insulating gas is blown from the buffer chamber 9 to the arc I9, it is not wasted. Here, the predetermined value is determined by the spring constant of the spring 29 and the pressure within the buffer chamber 9.

When the buffer cylinder IO is turned on, the buffer cylinder IO moves to the left in FIG. 1, and the inside of the buffer chamber 9 becomes negative pressure.
Insulating gas will be inhaled from the

H. Effects of the Invention As can be seen from the above explanation, the buffer type gas circuit breaker according to the present invention has the following effects.

First, a hot gas chamber is provided in which the pressure of insulating gas is rapidly increased by the heat of the arc generated between the fixed arcing contact and the movable arcing contact and is automatically blown onto the arc, resulting in the following effects.

(a) The pressure in the hot gas chamber increases due to the arc energy, and high-pressure insulating gas is blown onto the arc when the arc is opened, so the arc is extinguished in a short time, and then the compressed insulating gas in the buffer chamber The insulation recovery characteristics between the two are improved. Therefore, the distance between poles for cutting off becomes small.

(b) If the breaking current is large, the pressure in the hot gas chamber due to arc energy will also be greater, and the insulating gas in the hot gas chamber alone is sufficient to extinguish the arc. This eliminates the need for a means for spraying the air, making it possible to downsize the buffer cylinder, reduce the stroke of the drive rod, reduce the opening speed, reduce the drive means, and reduce drive energy, resulting in lower costs. Become.

(d) By reducing the opening speed, it is possible to avoid increasing the size and weight of the circuit breaker, and the reliability of its mechanical performance is greatly improved.

The second discharge path for guiding the insulating gas in the buffer chamber to the vicinity of the insertion hole is made narrower than the first discharge path for guiding the insulating gas in the hot gas chamber to the vicinity of the insertion hole, so the pressure in the hot gas chamber can be reduced efficiently. While the pressure rises well, the pressure rise in the puffer chamber is suppressed,
The arc is extinguished reliably, and resistance is prevented from being applied to the drive of the drive rod.

A pressure regulating valve is installed between the hot gas chamber and the buffer chamber, so the pressure in the hot gas chamber will never exceed a predetermined value.
Prevents danger. Further, since the insulating gas discharged from the hot gas chamber is blown from the buffer chamber to the arc, the insulating gas is not wasted and is effectively utilized.

[Brief explanation of drawings]

Figures 1 to 3 relate to an embodiment of the buffer type gas circuit breaker according to the present invention, in which Figure 1 is a sectional view at the time of closing, Figure 2 is a sectional view during shutdown, and Figure 3 is a sectional view at the time of completion of shutdown. 4 is a sectional view of a conventional buffer type gas circuit breaker. 4...Fixed arcing contact, 5...Hollow part, 7
... Movable arcing contact, 8... Drive rod, 9... Buffer chamber, 12a... First discharge path, +2
b...Second discharge path, 13...Insulating nozzle, 16...
Hollow rod, 17... Piston, 20a... First partition, 20b... Second partition, 2I... Hot gas chamber, 22
...Separator, 26...Pressure regulating valve. 11

Claims (1)

[Claims] (1) While a fixed arcing contact is fixed in an insulating gas, a drive rod with a hollow tip is provided so that it can be driven along the axis of the fixed arcing contact, and the fixed arcing contact can be freely inserted into and removed from the drive rod. The tip of the rod is a movable arcing contact, a buffer chamber surrounding the drive rod is provided outside near the tip of the drive rod, and an insulating nozzle having an insertion hole through which a fixed arcing contact is inserted airtight is a movable arcing contact. By providing it so as to cover the
In a buffer type gas circuit breaker, a discharge path extending from the buffer chamber to the vicinity of the insertion hole is formed between a movable arcing contact and an insulating nozzle, and a suction/exhaust means for sucking in and discharging insulating gas into the buffer chamber is provided. By forming a hot gas chamber in the buffer chamber and providing a substantially cylindrical separator between the insulating nozzle and the movable arcing contact, a first discharge path and a buffer chamber are formed to guide the insulating gas in the hot gas chamber to the vicinity of the insertion hole. The insulating gas is divided into a second discharge path leading to the vicinity of the insertion hole, the second discharge path is made narrower than the first discharge path, and a pressure regulating valve is provided between the hot gas chamber and the buffer chamber. Buffer type gas circuit breaker.