JPH0797468B2 - Puffer type gas circuit breaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Purpose of the Invention] (Field of Industrial Application) The present invention is used in a substation or a switching station of a power system.
The present invention relates to a puffer type gas circuit breaker using SF ₆ gas as an arc extinguishing medium.

(Prior Art) A puffer type gas circuit breaker has a structure shown in FIG. In this system, the puffer cylinder moves in the case of FIG. 4 with the opening and closing operation of the contacts, and the puffer chamber is compressed by the relative movement with the puffer piston. At this time,
High-pressure gas is created in the puffer chamber, and this gas is blown out through a nozzle to create a high-speed gas stream, which is then blown to the arc to quench the arc. In this way, since the high-pressure gas is generated by the puffer operation accompanying the opening / closing operation, it is not necessary to store the high-pressure gas like a two-pressure type circuit breaker, and it is not necessary to control the blowing, and the structure is simplified. It has a great advantage. In addition, as an arc extinguishing gas, SF
_{Since 6} gases are used, the insulation performance is excellent, and today it is the mainstream of high-voltage circuit breakers of 72 kV or higher.

It is conventionally known that a puffer type gas circuit breaker has a nozzle blocking phenomenon. This is a phenomenon in which the nozzle, which is the gas outlet, is blocked by the arc when the current increases. In such a situation, the gas in the puffer chamber has no outlet, and the compression efficiency is improved. Further, the arc energy will flow back into the puffer chamber, and the gas in the puffer chamber will be compressed not only mechanically but also thermally. On the other hand, since the arc diameter becomes smaller when approaching the vicinity of the current zero point, the gas in the puffer chamber will be blown out again through the blowout port,
This cools and breaks the arc.

The breaking performance of the puffer type gas circuit breaker depends on two factors, namely, the blowing pressure and the blowing flow rate. The current interrupting ability mainly depends on the spray pressure, and the withstand voltage characteristics mainly depend on the spray flow rate.Therefore, in the 300 kV class ultra-high voltage circuit breaker, the method of increasing the spray flow rate by increasing the nozzle diameter is adopted. In the high-voltage circuit breaker, a method of increasing the spray pressure by reducing the nozzle diameter is adopted.

(Problems to be Solved by the Invention) However, with the recent miniaturization and reduction of driving force, the number of methods using an electric spring operating mechanism for driving tends to increase. The electric spring operating mechanism obtains a strong force at the initial stage of opening when the spring is sufficiently compressed, but becomes weak at the end of opening when the spring is released. Therefore, if the gas pressure in the puffer chamber rises abnormally, the reaction force will increase, and in the worst case, it will start moving in the opposite direction. It is known that when this phenomenon occurs, the blocking performance is deteriorated.

In view of an abnormal point, the present invention aims to provide a puffer type gas circuit breaker that does not start moving in the opposite direction due to the reaction force of the puffer chamber even by the electric spring operating mechanism in which the force becomes weak at the end of opening. To do.

[Structure of Invention]

(Means for Solving the Problems) In the present invention, the operation rod 16 or the puffer cylinder 13 is composed of two layers, the inner and outer layers, and the puffer chamber 15 is divided into a compression chamber 15a and a gas chamber 15b. And the inside of the nozzle 11 are directly communicated with each other through the gas passage 12a, and the compression chamber 15a and the gas chamber 15
A buffer type gas circuit breaker is provided, which is connected to b in the puffer chamber 15.

(Operation) The drive unit performs the opening operation according to the opening command. This motion is transmitted to the operation rod 16, and first, the movable energizing contact 8
Is separated from the fixed energization contact 5. Next, the movable arc contactor 9 is separated from the fixed arc contactor 7 to generate an arc 20. During this time, the puffer cylinder 13 and puffer piston 14
The compression chamber 15a of the puffer chamber 15 is compressed by the relative motion of the. This gas partially flows into the gas chamber, but most of it cools the arc 20 blown out from the nozzle 11 through the gas passages 12 and 12a. When a large current is applied, the gas heated by being exposed to the arc 20 flows backward to the puffer chamber 15 through the gas passages 12 and 12a to increase the gas pressure. Gas chamber 15b even at the end of opening
Because of this, the gas pressure in the compression chamber 15a does not rise extremely.
In this way, it is possible to control the movement in the opposite direction that reduces the reaction force by suppressing the gas pressure rise at the end of opening and reduces the blocking performance.

(Embodiment) The configuration of the present invention will be described based on an embodiment shown in FIG. The fixed portion supported by an insulator or the like in the container has a fixed arc contactor 7 and a fixed energization contactor 5 covered with a shield 6. The fixed arc contact 7 and the fixed energizing contact 5 face the movable arc contact 9 and the moving energizing contact 8, respectively. The movable arc contactor 9 is supported by the operation rod 16 together with the puffer cylinder 13. The operating rod 16 is connected to a drive unit (not shown). The operation rod 16 is provided with a concentric cylinder 16a on the outer side thereof, and the cylinder 16a and the operation rod 16 constitute a gas chamber 15b. As a result, the puffer chamber 15 includes the cylinder 16a and the puffer cylinder 13a.
A gas chamber 15b divided into a compression chamber configured by inserting a puffer piston 14 supported by an insulator or the like between
And the compression chamber 15a communicate with each other on the movable arc contact side of the puffer chamber 15. The nozzle 1 is provided on the front surface of the puffer cylinder 13 so as to surround the movable arc contactor 8, and the movable energization contactor 8 is provided.
Fixed by. A gas passage 12 is formed between the movable arc contact 9 and the nozzle 11, and is connected to the gas passage 12a of the puffer cylinder 13 to connect the puffer chamber 15 and the opening of the nozzle 11.

The operation of this embodiment will be described. The drive unit performs the opening operation according to the opening command. This operation is the operation rod 16
First, the movable energizing contact 8 is transferred to the fixed energizing contact 5
More open. Next, the movable arc contactor 9 is separated from the fixed arc contactor to generate an arc 20. During this period, the compression chamber 15a of the puffer chamber 15 is compressed by the relative movement of the puffer cylinder 13 and the puffer piston 14. Compressed compression chamber 15a
This gas cools the arc 20 blown from the nozzle 11 through the gas passages 12 and 12a. At the time of a large current, the gas heated by being exposed to the arc 20 flows back to the puffer chamber 15 through the gas passages 12 and 12a, but most of the gas flows into the gas chamber 15b to increase the gas pressure. , It does not contribute much to the gas pressure rise in the compression chamber. Therefore, the gas pressure in the compression chamber does not rise abnormally even at the end of opening.

The effects of this embodiment will be described. In this way, it is possible to suppress the reaction force by suppressing the gas pressure rise in the compression chamber 15a at the end of opening, thereby suppressing the movement in the opposite direction that deteriorates the blocking performance. In addition, since the gas in the gas chamber 15b contributes to shutoff even at the end of opening, it is possible to shut off even when the amount of gas is small, which is also effective in expanding the shutoff time.

Another embodiment of the present invention will be described. In the embodiment shown in FIG. 2, a concentric cylinder is provided inside the puffer cylinder 13.
The cylinder 13a and the puffer cylinder 13 form a gas chamber 15b. Puffer piston is operating rod 16
And the cylinder 13a, the compression chamber 15a is formed. As described above, when the gas chamber 15b is provided outside the compression chamber 15a, the large gas chamber 15b can be formed with a relatively small outer diameter. Therefore, the method of FIG. 2 is effective when the breaking current is large and the pressure rise due to thermal energy is high. On the other hand, the method of FIG. 1 is effective when the breaking current is small.

1 and 2, the compression chamber 15a and the gas chamber 15b are connected in the puffer cylinder 13. In this way, the compression chamber 15a
Since the connection between the gas chamber 15b and the gas chamber 15b is improved, it is effective to reduce the gas pressure in the compression chamber, but a part of the gas in the compression chamber is also released to the gas chamber, so the spraying effect is reduced. On the other hand, as shown in FIG. 3, the cylinder 13a or 16a is lengthened to provide a gas flow path.
If they are connected by 12a, the effect of lowering the pressure is reduced, but the effect of blowing gas is increased.

〔The invention's effect〕

According to the present invention, the operating rod 16 or the cylinder 16a or 13a provided in the puffer cylinder 13
By dividing the puffer chamber 15 into the compression chamber 15a and the gas chamber 15b, most of the arc energy that flows back into the puffer chamber 15 via the gas passage 12 or 12a at the time of a large current is absorbed in the gas chamber 15b. , The reaction force can be reduced by suppressing the excessive pressure rise in the compression chamber, and the movement in the opposite direction that reduces the cutoff performance can be suppressed, and when the gas amount at the end of opening is small. Since new gas in the gas chamber 15b is replenished with, it is also effective in expanding the time width during which the gas can be shut off.

[Brief description of drawings]

FIG. 1 is a view showing the vicinity of contacts of a puffer cylinder type gas circuit breaker according to the present invention, FIG. 2 is a view showing another embodiment of the present invention, and FIG. 3 is a view showing another embodiment of a groove structure, FIG. 4 is a view showing the structure of a conventional puffer type gas circuit breaker. 5 ... Fixed energizing contact, 6 ... Shield 7 ... Fixed arc contact, 8 ... Movable energizing contact 9 ... Movable arc contact, 11 ... Nozzle 12, 12a ... Gas passage, 13 ... Puffer cylinder 13a …… Cylinder, 14 …… Puffer piston 15 …… Puffer chamber, 15a …… Compression chamber 15b …… Gas chamber, 16 …… Operating rod 16a …… Cylinder, 20 …… Arc

Claims (3)

[Claims] 1. A movable arc contactor having a pair of contacts in a container in which an arc extinguishing medium is enclosed, and a fixed arc contactor supported by the container by an insulator or the like and a movable arc contactor facing the movable arc contactor. Connect the arc contactor and puffer cylinder to the operating rod,
The operating rod is connected to the drive unit via an insulator, etc., and the puffer piston is supported by the container via the insulator so that it slides between the operating rod and the puffer cylinder. In a puffer-type gas circuit breaker in which a nozzle is attached so as to cover the cylinder, a gas chamber is formed by providing a cylinder concentric with the operation rod on the outside of the operation rod, and a puffer piston is inserted between the puffer cylinder and the cylinder for compression. A chamber is formed, the compression chamber and the space inside the nozzle are directly connected by a gas passage formed in the front surface of the puffer cylinder, and the gas chamber and the compression chamber are connected in the puffer chamber surrounded by the puffer cylinder and the operating rod. Puffer type gas circuit breaker. 2. A movable arc contactor having a pair of contact points in a container in which an arc extinguishing medium is enclosed, and a fixed arc contactor supported by the container by an insulator or the like and a movable arc contactor facing the movable arc contactor. Connect the arc contactor and puffer cylinder to the operating rod,
The operating rod is connected to the drive unit via an insulator, etc., and the puffer piston is supported by the container via the insulator so that it slides between the operating rod and the puffer cylinder.A movable arc contactor is attached to the front of the puffer cylinder. In a puffer-type gas circuit breaker with a nozzle attached so as to cover it, a gas chamber is formed by providing a cylinder concentric with the puffer cylinder inside the puffer cylinder, and inserting a puffer piston between the operating rod and the cylinder to create a compression chamber. The compression chamber and the space inside the nozzle are directly connected by a gas passage formed in the front surface of the puffer cylinder, and the gas chamber and the compression chamber are connected in the puffer chamber surrounded by the puffer cylinder and the operating rod. Characteristic puffer type gas circuit breaker. 3. A puffer type gas circuit breaker according to claim 1, wherein a cylinder reaches the gas passage.