JPS63110519A - Buffer type gas breaker - Google Patents

Abstract

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

Description

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

(Prior Art) A puffer-type gas circuit breaker has a puff mechanism including a pant 1 cylinder and a pack 7 piston that perform relative movement on its movable contact portion. During the breaking operation of this puffer type gas circuit breaker, the puffer cylinder moves as the contacts open and compresses the insulating gas in the puffer chamber through relative movement with the puffer piston. At this time, when the high-pressure insulating gas created in the puffer chamber is blown out of the nozzle at the contact part, a high-speed gas flow is created, and this high-speed gas flow is blown onto the arc that has formed between the contacts to cool it and extinguish it. .

In this way, puffer-type gas circuit breakers create high-pressure gas through the puffer action that accompanies the opening operation, so unlike dual-pressure type circuit breakers, there is no need to constantly store high-pressure gas and control the blowing pressure. , has the great advantage of simplified structure. SF is also used as an arc-extinguishing gas.
Because it uses 6 gases, it has excellent insulation performance,
Today, high voltage circuit breakers of 72 V or higher are the mainstream.

On the other hand, it has been known that puffer type gas circuit breakers have a nozzle clogging phenomenon. This is a phenomenon in which when the current increases, the tip of the nozzle, which is the gas outlet, is blocked by the arc. In such a situation, the gas in the puffer chamber has no outlet and the compression efficiency increases rapidly.

Further, the arc energy flows back into the puffer chamber, and the gas within the puffer chamber is not only mechanically compressed, but also thermally compressed.

Further, as the current approaches the zero point, the arc diameter becomes smaller, so the gas in the puffer chamber is blown out from the outlet again, thereby cooling the arc and cutting it off.

The breaking performance of a roughly puffer type gas circuit breaker depends on two things: the blowing pressure and the blowing flow rate of the insulating gas.

The current interrupting ability mainly depends on the blowing pressure, and the withstand voltage characteristics mainly depend on the blowing flow rate.For 300KV class ultra-high pressure circuit breakers, a method is adopted in which the nozzle diameter is increased to increase the blowing flow rate. , 72KV class high pressure circuit breakers adopt a method of increasing the blowing pressure by reducing the nozzle diameter.

(Problems to be Solved by the Invention) However, in recent puffer-type gas circuit breakers, as the size of the circuit breaker becomes smaller and driving power is reduced, an electric spring operation mechanism is used for the opening/closing drive mechanism of the circuit breaker. is also on the rise. The electric spring operation mechanism of the circuit breaker uses the released force of the stored spring as the driving force for opening the contacts.Due to the nature of the spring that is the driving force source, the spring is sufficiently compressed to open the contact. A strong force is obtained at the beginning, but the force becomes weak at the end of the opening when the spring is released. For this reason, in a puffer type gas circuit breaker, if the gas pressure in the puffer chamber increases abnormally due to nozzle blockage phenomenon during such type of operation or reverse flow of arc energy into the puffer chamber, the reaction force increases, and in the worst case In this case, the contact point starts to move in the opposite direction to the opening direction.

It is known that when this phenomenon occurs, the interrupting performance deteriorates.

An object of the present invention is to provide a puffer-type gas circuit breaker that prevents an abnormal rise in gas pressure in the puffer chamber at the final stage of circuit breaker opening, and that also increases the amount of effective gas and improves circuit breaker performance. It is about providing.

[Structure of the Invention] (Means and Effects for Solving Problems) The puffer type gas circuit breaker of the present invention has a fixed contact part and a movable contact part provided with a puffer mechanism in a tank sealed with insulating gas. The puffer mechanism has a first piston plate and a second piston plate that cooperate with the inner surface of the puffer cylinder and the circumferential surface of the operating rod to partition a puffer chamber and a gas chamber, respectively. A groove for communicating the puffer chamber and the gas chamber is provided on the inner surface of the puffer cylinder or the circumferential surface of the operating rod, which forms one driving surface of the first piston plate, at a position near the end of opening during the shutoff operation. It is something to do.

In the present invention, when near the end of the opening during the shutoff operation, the puffer chamber and the gas chamber communicate with each other via the communication groove of the sliding movement of the first piston plate, so that the gas pressure in the puffer chamber is abnormal. In addition to preventing such a rise, the effective amount of gas is increased to improve shutoff performance.

(Example) The present invention will be described below with reference to an example shown in FIGS. 1, 2, and 3. In FIG. 1, a buffer 1 type gas circuit breaker 1 according to the present invention has a fixed electrode part 3 in a sealed tank 2.
A movable electrode section 5 carrying the puffer mechanism 4 is disposed, and the movable electrode section 5 is moved forward and backward by the drive mechanism 6 via the operating rod 7, thereby bringing the movable electrode section 5 and the fixed electrode section 3 into and out of contact with each other. The arc generated between the electrodes 3 and 5 is extinguished by blowing high-pressure insulating gas generated in the puffer mechanism 4.

The fixed electrode part 3 has a fixed arc contact 1o installed on a conductive member 9 attached to a sealed tank 1 via an insulating stand 8, and a fixed current-carrying contact 11 and a shield 1 are installed around the contact 10.
2 concentrically surrounded.

The conductive member 9 is connected to the center conductor 14 of the sunrise bushing 13 to serve as one line end. The movable electrode section 5 includes a movable arc contact 15 provided at the tip of an operating rod 7 made of a hollow conductor, and a nozzle 17 and a movable current-carrying contact 18 surrounding the movable arc contact 15 concentrically via a gas passage 16. It consists of

The puffer mechanism 4 supported on the movable electrode section 5 is composed of a puffer cylinder 19 and a puffer piston 20, which are integrated with the tip of the operating rod 7 and carry the movable arc contact 15 and the movable current-carrying contact 18. The puffer piston 20 includes a conductive member 21 and an insulating stand 22.
It is fixed to the side of the drive mechanism 6 via. The conductive member 21 is connected to the center conductor 24 of the outlet bushing 23 to serve as the other line end.

Therefore, in the present invention, the puffer is an improvement on structure 4. That is, as shown in FIG. 2, there are two first and second pistons that slide on the inner surface of the pants 1 cylinder 19 and the circumferential surface of the operating rod 7 at a predetermined interval at the tip of the rod of the buff 7 piston 20. Plates 20a and 20b are provided.

The first screw plate 20a cooperates with the inner surface of the puffer cylinder 19 and the outer peripheral surface of the operating rod 7 to form the puffer chamber 25.
The second piston plate 20b forms a pan fan cylinder 1.
A gas chamber 26 is formed together with the lower surface of the inner piston plate 20a of No. 9 and the outer peripheral surface of the operating lock door.

Furthermore, in the present invention, a communication groove 27 as shown in FIG. 4 is formed on the inner circumferential surface of the root portion of the inner surface of the puffer cylinder 19. This communication groove 27 is formed so that the inner surface of the puffer cylinder 19 slides on both piston plates 20a and 20b during the opening operation of the gas circuit breaker, and at the final stage of opening, the communication groove 27 slides on the first piston plate 20a. When communicated, 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 explained. In FIG. 1, the disconnection operation of the gas circuit breaker 1 is executed by the drive unit 6 performing the opening operation in accordance with the opening command. This opening operation of the drive unit 6 is transmitted to the operating rod 7, and the movable current-carrying contact 18 first moves to the right in the figure and separates from the fixed current-carrying contact 11. Next, the movable arc contact 15 separates from the fixed arc contact 10, and an arc A is generated between the two.

During this time, the puffer cylinder 19 and the puffer piston 20
The insulating gas in the puffer chamber 25 is compressed by the relative movement with the puffer chamber 25. When the small current is cut off, the gas in the packs 7 to 25 passes through the gas passages 28 and 16 as shown by the arrow to the nozzle 17.
The arc A is cooled by blowing out more air.

When the large current is cut off, on the other hand, the gas heated by exposure to the arc A flows back into the puffer chamber 25 through the gas passages 16 and 28, rapidly increasing the gas pressure.

However, at the end of the opening period, when the communication groove 27 provided all around the inner surface of the puffer cylinder 19 passes through the first piston plate 20a, the puffer chamber 25 and the gas chamber 26 are communicated through the groove 27, and the puffer chamber 25 The high-pressure gas moves to the gas chamber 26, and the gas pressure is averaged. Therefore, by suppressing the rise in gas pressure in the puffer chamber 25 at the final stage of opening of the circuit breaker, the reaction force against the movement of the operating rod 7 is reduced, and movement in the opposite direction that would degrade the breaking performance of the circuit breaker is suppressed.

Next, in another embodiment shown in FIG. 3, a communication groove 27 for controlling communication between the puffer chamber 25 and the gas chamber 26 of the puffer mechanism
is provided on the outer circumferential surface of the base of the operating rod 7 as shown in FIG.

In this embodiment as well, in the breaking 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 final stage of opening, 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, in the present invention, the puffer mechanism has a buff 1 surrounded by two piston plates and a gas chamber, and the puffer chamber and the gas chamber are connected near the end of electrode opening. By configuring the pipes to communicate with each other, it is possible to prevent an abnormal rise in gas pressure within the puffer mechanism, and also to increase the amount of effective gas and improve the shutoff performance.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one embodiment of the puffer type gas circuit breaker of the present invention, FIG. 2 is a cross-sectional view showing an enlarged cut-off section of FIG. 1, and FIG. 3 is another embodiment of the present invention. FIGS. 4 and 5 are cross-sectional views taken along lines A-A and B-B in FIGS. 2 and 3. FIGS. 1... Puffer type gas circuit breaker 2... Sealed tank 3... Fixed contact part 4... Puffer mechanism 5... Movable contact part 6... Drive mechanism 7... Operating rod 10...・Fixed arc contact 11...Fixed energizing contact 15...Movable arc contact 16...Gas passage 17...Nozzle 18...Movable energizing contact 19...Pants 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 (8733 ) Agent Patent Attorney Yoshiaki Inomata (Baka
1 person) Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] (1) A fixed contact part and a movable contact part equipped with a puffer mechanism are arranged so as to be movable relative to each other in a tank sealed with insulating gas, and the puffer mechanism moves in conjunction with the inner surface of the puffer cylinder and the drawing of the operating rod. an inner surface of a puffer cylinder, which has a first piston plate and a second piston plate that partition a puffer chamber and a gas chamber, respectively; Or a puffer-type gas circuit breaker, which has a communication groove on the circumferential surface of the operating rod that communicates the puffer chamber and the gas chamber.