JPH01313825A - Buffer type gas-blast circuit-breaker - Google Patents

Abstract

PURPOSE:To increase shutting off capacity by providing a second hot gas chamber being an introducing flow path to the buffer chamber of insulation gas of hollow part of a drive rod and a check valve for preventing a back flow. CONSTITUTION:There are provided, in a piston 17, first hot gas chamber 21 where the pressure of insulation gas increases rapidly due to the heat of arc generated between a fixed arcing contact 4 and a movable arcing contact 7 and is sprayed to the arc automatically, a second hot gas 27 for introducing insulation gas inside a hollow part 6 of a drive rod 8 into a buffer chamber 9, and a check valve 29 flowing insulation gas to only the chamber 9 from the chamber 27. High pressure insulation gas is sprayed to arc as the pressure in the chamber 21 increases. It is thus possible to eliminate arc in a short arc time and to improve insulation restoring characteristic between electrodes by the insulation gas compressed thereafter in the chamber 9.

Description

[Detailed description of the invention] A. Industrial application field The present invention relates to the structure of a puffer type gas circuit breaker.

B0 Summary of the Invention The present invention provides a puffer-type gas circuit breaker that extinguishes the arc by blowing insulating gas in the puffer chamber onto the arc when separating the movable arcing contact from the fixed arcing contact. The movable arcing contact side of the puffer chamber is designated as the first hot gas chamber, while a second hot gas chamber is provided to form a flow path for introducing the insulating gas in the hollow part of the drive rod into the puffer chamber, and to prevent backflow. By installing a check valve in the flow path, the insulation from the second hot gas chamber, which has become high-pressure due to the energy of the arc between the poles, is introduced into the puffer chamber, and higher-pressure insulating gas is blown onto the arc. The breaking capacity is increased by blowing insulating gas from the second hot gas chamber, which has become high pressure due to the energy of the arc between the poles, onto the arc.

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

The structure of a conventional puffer type gas circuit breaker is shown in FIG. As shown in the figure, the puffer 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 of the main contact.

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. a puffer cylinder 10 forming a puffer chamber 9 between it and the drive rod 8;
It is fixed to the puffer cylinder 10 so as to cover the movable arcing contact 7, and has an insertion hole 1 at the tip.
1 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 (not shown). The ring-shaped piston 17 is attached to a fixed part and is slidably provided between the drive rod 8 and the puffer cylinder IO. Note that 18 is a sealing material. Each unit is SF
It is installed in an insulating gas such as a gas, and constitutes a puffer type gas circuit breaker.

In such a puffer type gas circuit breaker, the drive rod 8
When the drive rod 8 is driven to the left in the figure to supply the gas, insulating gas is sucked into the puffer chamber 9 from the insertion hole 2, and when the drive rod 8 is driven to the right in the figure to shut off the gas, the insulating gas is sucked into the puffer 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 15. The driving speed of the driving rod 8 is generally 8 to 10 m/s.

D1 Problem to be Solved by the Invention However, with the increase in the capacity of power systems, puffer type gas circuit breakers are required to have a large voltage and breaking current per trip, and the conventional puffer type gas circuit breakers are 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 puffer chamber and spray high-pressure insulating gas until the arc is extinguished. It is necessary to drive the drive rod at high speed with a large stroke, but this not only increases the size of the puffer 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 puffer type gas circuit breaker that solves the above problems.

81 Means for Solving the Problems The structure of the present invention to achieve 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 to the fixed arcing contact. A movable arcing contact is provided at the tip of a drive rod that is movable along the axis, and a fixed arcing contact can be freely inserted and removed, and an outer diameter larger than the outer diameter of the drive rod is provided on the outside near the tip of the drive rod. By inserting a puffer cylinder having a structure, a puffer chamber opening toward the side opposite to the fixed arcing contact is provided between the drive rod and the puffer cylinder, and an insulating nozzle is coupled to the puffer cylinder so as to cover the movable arcing contact. A discharge path through which the puffer chamber and the tip of the movable arcing contact communicate is formed between the movable arcing contact and the insulating nozzle, and a piston that is slidable and movable within the puffer chamber is attached to the puffer cylinder and the drive rod. In a puffer-type gas circuit breaker fixed to a fixed part via While using a gas chamber, a hollow rod is used as the rod connected to the piston, into which the driving rod is inserted.
By forming a partition wall protruding toward the drive rod, a second hot gas chamber is provided between the drive rod and the hollow rod and between the piston and the partition wall, and a communication hole is formed in the piston. The communication hole is also provided with a check valve that allows insulating gas to flow only from the second hot gas chamber into the puffer chamber, and the drive rod is provided with a communication hole that communicates the hollow part with the second hot gas chamber. do.

11 When the movable arcing contact is separated from the fixed arcing contact when the action is cut off, the pressure of the insulating gas in the hollow part of the drive rod increases due to the heat of the arc generated between the poles, and the insulating gas flows into the second hot gas chamber. Enter the puffer room through it. This insulating gas is combined with the insulating gas in the puffer chamber to create a high pressure inside the puffer chamber, and this high-pressure insulating gas is pressed by a piston and blown onto the arc.

On the other hand, when the arc is cut off, the pressure of the insulating gas in the first hot gas chamber increases due to the heat of the arc generated between the electrodes, and the insulating gas is blown onto the arc to extinguish it. Thereafter or at the same time, the insulating gas in the puffer chamber pushed out by the piston rapidly increases the insulation recovery characteristics between the electrodes, and the interruption is completed.

The larger the breaking current, the larger the arc energy, and the -
The pressure of the insulating gas in the second hot gas chamber also increases, and the arc extinguishing ability increases.

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 puffer type gas circuit breaker, so the same parts will be given the same reference numerals and explanations will be omitted, and only the different parts will be explained.

(a) Structure of the Embodiment As shown in FIG. 2, a partition wall 20 is provided that partitions the conventional puffer chamber 9 along the driving direction of the drive rod 8. This partition wall 20 is provided between the puffer cylinder 10 and the drive rod 8, thereby forming a first hot gas chamber 21 on the movable arcing contact 7 side. And bulkhead 2
0 is provided with a plurality of communication holes 22 and check valves 23 so that the insulating gas can flow only from the puffer chamber 9 to the first hot gas chamber 21.

On the other hand, as shown in the figure, a hollow rod 16 has conventionally been used as the rod that supports the piston 17. A partition wall 26 is provided on the inner peripheral surface of the hollow rod 16 near the piston 17 and projects toward the drive rod 8 .

The partition wall 26 is provided over the entire circumference in the inner circumferential direction, and the partition wall 26
There is a slight gap between the drive rod 8 and the drive rod 8. As a result, a second hot gas chamber 27 is formed between the drive rod 8 and the hollow rod 16 and between the piston 17 and the partition 26.

The piston I7 is provided with a plurality of communication holes 28 along the circumferential direction for communicating the second hot gas chamber 27 and the puffer chamber 9. A check valve 29 is provided that allows insulating gas to flow only into the chamber 9. Furthermore, the communication hole 6 that communicates the hollow portion 5 and the second hot gas chamber 27 is conventionally provided for exhaust. This communication hole 6 needs to be located at the left end of the second hot gas chamber 27 as shown in FIG. 2 in a state in which the drive rod 8 starts to be driven at the time of shutoff, that is, in a state in which it is turned on.

(b) To start the operation of the embodiment, as shown in FIG. 2, drive the drive port 8 to the left in the figure, and fit the fixed arcing contact 4 into the movable arcing contact 7. At this time, since the hollow rod 16 is fixed, the piston 17 moves to the right relative to the puffer cylinder IO, and the insulating gas outside the puffer cylinder IO flows through the communication hole 6. The gas is sucked into the puffer chamber 9 through the exhaust hole 15 and the communication hole 28.

Next, a case in which shutoff is performed will be explained.

When the drive rod 8 is driven to the right in FIG. 1, the movable arcing contact 7 separates from the fixed arcing contact 4 and an arc 19 is generated between the poles. rises instantly.

The insulating gas, which has become highly pressurized due to the temperature rise, passes through the second hot gas chamber 27 from the communication hole 6 and moves from the communication hole 28 to the puffer chamber 9.

Conventionally, the insulating gas in the puffer chamber 9 is pushed out by the piston 17 and blown onto the arc 19 through the discharge path 12, but since high-pressure insulating gas is supplied from the second hot gas chamber 27, the gas is at a higher pressure than before. Insulating gas can be blown onto the arc 19 at a higher speed. Therefore, the arc can be extinguished in a short arc time. As the drive rod 8 approaches the cutoff completion position, the communication hole 6 moves to the right in the figure from the position of the second hot gas chamber 27, and the communication hole 6 comes to the position of the exhaust hole 15. Then, the insulating gas ionized by the arc 19 flows through the communication hole 6. 100% of the gas is discharged to the outside through the exhaust hole 15, and as a result, the interelectrode insulation recovery characteristics are enhanced and the interrupting characteristics are improved.

The larger the interrupting current is, the more heat is generated by the arc 19, the pressure of the insulating gas in the hollow part 5 is also greater, the pressure in the puffer chamber 9 is also greater, and the arc extinguishing ability is greater. A portion of the insulating gas in the second hot gas chamber 27 is exhausted from between the partition wall 26 and the drive rod 8 through the exhaust hole 15 .

On the other hand, when an arc occurs between the poles, the pressure of the insulating gas in the first hot gas chamber 21 also increases due to the arc energy. The insulating gas in the first hot gas chamber 21 whose pressure has increased is blown onto the arc 19 from the discharge path 12 to extinguish the arc, and then or simultaneously the insulating gas in the puffer chamber 9 is released into the piston 1.
7 through the communication hole 22, and the first hot gas chamber 2
1. It is blown onto the arc 19 through the discharge path 12.

For this reason, the insulation recovery characteristics between the poles after the arc is extinguished rapidly increase, and the interrupting characteristics improve.

In this way, high-pressure insulating gas is supplied into the puffer chamber 9 from the second hot gas chamber 27, and arc! 9, the temperature of the insulating gas in the first hot gas chamber 2I rises rapidly, becomes high pressure, and is blown onto the arc 19, so that the arc can be interrupted in a short time.

H. Detailed Description of the Invention As described above, according to the puffer type gas circuit breaker according to the present invention, the pressure of the insulating gas suddenly increases due to the heat of the arc generated between the fixed arcing contact and the movable arcing contact, automatically causing an arc. A first hot gas chamber to be blown is provided, and a second hot gas chamber is provided for guiding the insulating gas in the hollow part of the drive rod to the puffer chamber, and the insulating gas flows only from the second hot gas chamber into the puffer chamber. Since a check valve is provided on the piston, the following effects are achieved.

(a) As the breaking current increases, the arc energy also increases, and the pressure in the first hot gas chamber also increases, and high-pressure insulating gas is blown onto the arc, so the arc is extinguished in a short time, and then compressed in the puffer chamber. The insulating gas improves the insulation recovery characteristics between the electrodes. Therefore, the distance between poles for cutting off becomes small.

(b) The insulating gas, which has been rapidly increased in pressure by the arc energy, is led to the puffer chamber via the second hot gas chamber and is blown onto the arc at high speed, making it possible to interrupt the arc in a short time. As the breaking current increases, the arc energy increases and the pressure of the insulating gas becomes higher, so the arc extinguishing ability increases.

(c) Also, since the energy of the high-pressure insulating gas introduced from the second hot gas chamber to the puffer chamber is used to extinguish the arc, there is no need for a conventional means of blowing insulating gas at high speed to the arc. Therefore, the puffer cylinder can be made smaller, the stroke of the driving rod can be reduced, and the driving means can be made smaller and the driving energy can be reduced by reducing the opening speed, resulting in lower costs.

(d) Furthermore, 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.

[Brief explanation of the drawing]

Figures 1 and 2 relate to an embodiment of the puffer type gas circuit breaker according to the present invention, where Figure 1 is a sectional view when it is cut off, Figure 2 is a sectional view when it is turned on, and Figure 3 is a conventional puffer type gas circuit breaker. It is a sectional view of a gas circuit breaker. 4... Fixed arcing contact, 5... Hollow part,
7... Movable arcing contact, 8... Drive rod, 9... Puffer chamber, 10... Puffer cylinder, 12... Discharge path, I3... Insulating nozzle, 16...
・Hollow rod, I7...Piston, 20.26...
Partition wall, 21...First hot gas chamber, 22.28...Communication hole, 23.29...Check valve, 27...Second hot gas chamber.

Claims (1)

[Claims] (1) While the 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 and removed. The tip of the rod is a movable arcing contact, and a puffer cylinder with an outer diameter larger than the outer diameter of the drive rod is fitted on the outside near the tip of the drive rod to create a non-fixed position between the drive rod and the puffer cylinder. By providing a puffer chamber that opens to the arcing contact side and coupling an insulating nozzle to the puffer cylinder so as to cover the movable arcing contact, the discharge path where the puffer chamber and the tip of the movable arcing contact communicate is insulated from the movable arcing contact. In a puffer-type gas circuit breaker, in which a piston is formed between the nozzle, slidable between the puffer cylinder and the drive rod, and is movable within the puffer chamber, fixed to a fixed part via the rod, the drive direction of the drive rod is A partition wall is provided to partition the puffer chamber along the partition wall, and a communication hole is formed in the partition wall, and the movable arcing contact side of the puffer chamber is used as a first hot gas chamber, while a driving rod is inserted inside as the rod connected to the piston. By using a hollow rod and forming a partition wall that protrudes toward the drive rod over the entire circumference of the inner peripheral surface of the hollow rod, a partition wall is formed between the drive rod and the hollow rod and between the piston and the partition wall. A second hot gas chamber is provided, a communication hole is formed in the piston, a check valve is provided in the communication hole to allow insulating gas to flow only from the second hot gas chamber to the puffer chamber, and the drive rod is connected to the hollow part and the second hot gas chamber. A puffer-type gas circuit breaker characterized by having a communication hole for communicating with a chamber.