JP2635559B2 - Patch type gas circuit breaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a puffer type gas circuit breaker having an improved puffer mechanism.

(Prior Art) A puffer type gas circuit breaker carries a puffer mechanism composed of a puffer cylinder and a puffer piston which perform relative movement at a movable contact portion thereof. During the breaking operation of the puffer type gas circuit breaker, the puffer cylinder moves with the opening operation of the contact, and compresses the insulating gas in the puffer chamber by the relative movement between the puffer piston and the puffer piston. At this time, when a high-pressure insulating gas created in the puffer chamber is blown out from the nozzle at the contact portion, a high-speed gas flow is generated, and the high-speed gas flow of the insulating gas is generated between the contacts to blow an arc to cool and extinguish the arc. .

As described above, in the puffer type gas circuit breaker, in order to produce high-pressure gas by the puffer operation accompanying the opening operation, it is not necessary to always store the high-pressure gas and control the blowing pressure as in a two-pressure type circuit breaker. This has a great advantage that the structure is simplified. In addition, SF is used as an arc-extinguishing gas.
_{Because 6} gas is used, the insulation performance is also excellent,
Today, high voltage circuit breakers over 72KV are the mainstream.

On the other hand, it has been conventionally known that a puffer type gas circuit breaker has a nozzle clogging phenomenon. This is a phenomenon in which the tip of a nozzle, which is a gas outlet, is blocked by an arc when the current increases. In such a situation, the gas in the puffer chamber has no outlet and the compression efficiency rises rapidly. Further, the arc energy flows back into the puffer chamber, and the gas in the puffer chamber is not only compressed mechanically but also thermally. Further, as the arc diameter becomes smaller as the current gets closer to the current zero point, the gas in the puffer chamber is blown out from the outlet again, whereby the arc is cooled and cut off.

Furthermore, the shutoff performance of the puffer type gas circuit breaker depends on two factors: the blowing pressure and the blowing flow rate of the insulating gas. The current interruption capability mainly depends on the spray pressure, and the withstand voltage characteristics mainly depend on the spray flow rate.The 300 KV class ultra-high pressure circuit breaker adopts the method of increasing the spray flow rate by increasing the nozzle diameter. ,
For 72KV class high pressure circuit breakers, a method is adopted in which the nozzle diameter is reduced to increase the spray pressure.

(Problems to be solved by the invention) However, in recent puffer type gas circuit breakers,
With the reduction in size and the reduction in driving force, the number of systems using an electric spring operating mechanism for the opening / closing drive mechanism of the shutoff unit also tends to increase. The electric spring operating mechanism of the circuit breaker uses the accumulated force of the spring as the opening driving force of the contact, and the opening of the spring is sufficiently compressed due to the nature of the spring as the driving force source. A strong force is obtained in the initial stage, but the force is weakened at the end of the opening when the spring is released. For this reason, in the puffer type gas circuit breaker, when the gas pressure in the puffer chamber rises abnormally due to the nozzle clogging phenomenon during the opening operation and the reverse flow of arc energy into the puffer chamber, the reaction force increases, and in the worst case In this case, the contact starts to move in the direction opposite to the opening direction. It has been found that when this phenomenon occurs, the blocking performance is reduced.

An object of the present invention is to provide a puffer-type gas circuit breaker that prevents an abnormal increase in gas pressure in a puffer chamber at the end of the opening of the circuit breaker, and also increases an effective gas amount to improve the breaking performance. To provide.

[Structure of the Invention] (Means and Action for Solving the Problems) In the puffer type gas circuit breaker of the present invention, a fixed contact portion and a movable contact portion having a puffer mechanism are relatively placed in a closed tank in which insulating gas is sealed. In a puffer type gas circuit breaker configured so as to be able to move freely, the puffer mechanism is slid on the puffer cylinder fixed to the operation rod, the inner surface of the puffer cylinder and the peripheral surface of the operation rod, and is divided into a puffer chamber. Inner surface or operation rod of a puffer cylinder which has a first piston plate and a second piston plate formed between the gas chamber and a sliding surface of the first piston plate at a position near the end of opening when the shut-off operation is performed. A communication groove communicating the puffer chamber with the gas chamber is provided on the peripheral surface of the puffer chamber and the gas chamber, and the communication groove allows the puffer chamber to communicate with the gas chamber only at the end of opening. It is an.

In the present invention, at the time of the breaking operation, near the end of the opening, the puffer chamber and the gas chamber are connected by the communication groove, so that the gas pressure in the puffer chamber can be reduced and the heat of the arc is maintained until the end of the opening. The amount of gas effective for spraying can be increased by the cold gas in the gas chamber which is not affected by the above.

(Example) Hereinafter, the present invention will be described with reference to examples shown in FIGS. 1, 2 and 3. FIG. In FIG. 1, a puffer type gas circuit breaker 1 according to the present invention has a fixed contact portion 3 and a movable contact portion 5 carrying a puffer mechanism 4 in a closed tank 2, and the movable contact portion 5 is operated by a drive mechanism 6. Rod 7
To move the movable contact portion 5 and the fixed contact portion 3 apart from each other, and to extinguish the arc generated between the contact portions 3 and 5 by blowing the high-pressure insulating gas generated in the puffer mechanism 4. It is configured.

The fixed contact part 3 is provided with a fixed arc contact 10 on a conductive member 9 attached to the closed tank 3 via an insulating base 8, and the contact 10 is concentrically surrounded by a fixed current contact 11 and a shield 12. It is composed of The conductive member 9 is connected to the center conductor 14 of the outlet bushing 13 to form one line end. The movable contact portion 5 is provided with a movable arc contact 15 at the tip of an operating rod 7 made of a hollow conductor, and is concentrically surrounded by a nozzle 17 and a movable energizing contact 18 via a gas passage 16. It is composed of

The puffer mechanism 4 carried on the movable contact portion 5 is composed of a combination of a puffer cylinder 19 and a puffer piston 20 which are integral with the tip of the operating rod 7 and carry the movable arc contact 5 and the movable energizing contact 18. The puffer piston 20 is fixed to a side portion of the drive mechanism 6 via a conductive member 21 and an insulating base 22. The conductive member 21 is connected to the center conductor 24 of the outlet bushing 23 to form the other line end.

Thus, in the present invention, the puffer mechanism 4 is improved. That is, as shown in FIG. 2, two first and second piston plates 20a which slide on the inner surface of the puffer cylinder 19 and the peripheral surface of the operation rod 7 at a predetermined distance from the tip of the rod of the puffer piston 20. And 20b
Is provided. The first piston plate 20a is the puffer cylinder 1
9, the second piston plate 20b cooperates with the lower surface of the inner piston plate 20a of the puffer cylinder 19 and the outer peripheral surface of the operating rod 7 to form a gas chamber. 26.

Further, in the present invention, a communication groove 27 as shown in FIG. 4 is formed in the inner peripheral surface of the root portion of the inner surface of the puffer cylinder 19. When the gas circuit breaker opens, the communication groove 27 allows the inner surface of the puffer cylinder 19 to move between the two piston plates 20a, 20a.
When the communication groove 27 communicates with the first piston plate 20a at the end of the opening of the b, the puffer chamber 27 and the gas chamber 26 serve to communicate with each other.

Next, the operation of the puffer type gas circuit breaker according to the present invention will be described. In FIG. 1, the breaking operation of the gas circuit breaker 1 is executed by the driving unit 6 performing the opening operation in accordance with the opening command. The opening operation of the drive unit 6 is transmitted to the operation rod 7, and first, the movable energizing contact 18 moves rightward in the drawing to be separated from the fixed energizing contact 11. Next, the movable arc contact 15 is separated from the fixed arc contact 10, and an arc A is generated therebetween.

During this time, the insulating gas in the puffer chamber 25 is compressed by the relative movement between the puffer cylinder 19 and the puffer piston 20. At the time of the interruption of the small current, the gas in the puffer chamber 25 is blown out from the nozzle 17 through the gas passages 28 and 16 as shown by arrows, thereby cooling the arc A. When the large current is interrupted, the gas heated by exposure to the arc A flows back to the puffer chamber 25 through the gas passages 16 and 28, and the gas pressure is rapidly increased.

However, at the end of opening, when the communication groove 27 provided on the entire circumference of the inner surface of the puffer cylinder 19 passes through the first piston plate 20a, the puffer chamber 25 and the gas chamber 26 communicate with each other via the groove 27,
The high-pressure gas in the puffer chamber 25 moves to the gas chamber 26, and the gas pressure is averaged. Therefore, by suppressing the gas pressure in the puffer chamber 25 at the end of the opening of the circuit breaker, the reaction force against the movement of the operating rod 7 is reduced, and the movement in the opposite direction that reduces the breaking performance of the circuit breaker is suppressed.

Next, in another embodiment shown in FIG. 3, a communication groove 27 for controlling the communication between the puffer chamber 25 and the gas chamber 26 of the puffer mechanism 4 is formed on the outer peripheral surface of the root portion of the operation rod 7 as shown in FIG. It is characterized by being provided in.

Also in this embodiment, in the shut-off operation of the gas circuit breaker, when the communication groove 27 formed on the outer peripheral surface of the operating rod 7 passes through the first piston plate 20a at the end of the opening of the electrode, the puffer chamber 25 and the gas chamber 26 Are communicated through the groove 27, the high-pressure gas in the puffer chamber 25 moves to the gas chamber 25, and the gas pressure is averaged.

[Effects of the Invention] As described above, according to the present invention, the puffer mechanism has a gas chamber that is separated from the puffer chamber surrounded by the two-stage piston plate, and is provided only at the end of the opening operation during the shutoff operation. By configuring the puffer chamber and the gas chamber to communicate with each other, it is possible to prevent an abnormal increase in the gas pressure in the puffer mechanism and increase the effective gas amount to improve the shutoff performance.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a puffer type gas circuit breaker of the present invention, FIG. 2 is a sectional view showing an enlarged view of a breaking section of FIG. 1, and FIG. 3 is another embodiment of the present invention. FIGS. 4 and 5 are enlarged sectional views showing the cut-off portion, and are sectional views taken along lines AA and BB in FIGS. 2 and 3. FIG. DESCRIPTION OF SYMBOLS 1 ... Puffer type gas circuit breaker 2 ... Sealed tank 3 ... Fixed contact part 4 ... Puffer mechanism 5 ... Movable contact part 6 ... Driving mechanism 7 ... Operation rod 10 ... Fixed arc contact 11 ... Fixed energizing contact 15 Movable arc contact 16 Gas passage 17 Nozzle 18 Movable energizing contact 19 Puffer cylinder 20 Puffer piston 20a First piston plate 20b Second piston Plate 25… Puffer chamber 26… Gas chamber 27… Communication groove 28… Gas passage A… Arc

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hitoshi Mizoguchi 2-1 Ukishima-cho, Kawasaki-ku, Kawasaki City Inside the Toshiba Hamakawasaki Plant (72) Inventor Satoru Yanagibu 2-1 Ukishima-cho, Kawasaki-ku, Kawasaki-shi Toshiba Corporation Inside the Hamakawasaki Plant (56) References JP-A-53-132776 (JP, A) JP-A-51-63466 (JP, A) Jikai Sho 54-183668 (JP, U)

Claims (1)

(57) [Claims] 1. A puffer type gas circuit breaker wherein a fixed contact portion and a movable contact portion having a puffer mechanism can be relatively moved in a closed tank in which an insulating gas is sealed. It has a fixed puffer cylinder, and a first piston plate and a second piston plate which slide on the inner surface of the puffer cylinder and the peripheral surface of the operation rod, and have a gas chamber defined between the puffer chamber and the puffer chamber. A communication groove for communicating the puffer chamber and the gas chamber with an inner surface of the puffer cylinder or a peripheral surface of the operation rod which forms a sliding surface of the first piston plate at a position near the end of the opening at the time of the breaking operation. A puffer type gas circuit breaker, wherein the communication groove allows the puffer chamber and the gas chamber to communicate only at the end of opening.