JPS62241224A - Buffer type gas blast breaker - Google Patents

Abstract

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

Description

[Detailed Description of the Invention] [Purpose of the Invention (Industrial Application Field) The present invention relates to a paranoia type gas circuit breaker used in substations or switchyards of power systems, and in particular, to This invention relates to a puffer-type cass breaker that has improved insulation properties between a movable current-carrying contact and a fixed contact in the middle, making it possible to maintain the initial state even after opening and closing many times.

(Prior Art) In recent years, the capacity of power plants has continued to increase as the demand for electricity increases. Furthermore, due to the difficulty in constructing power plants in urban areas where large quantities of electricity are consumed, power transmission lines are becoming longer and there is a trend toward higher voltages to improve power transmission efficiency.

As power transmission systems become larger in capacity and higher in voltage, the breaking capacity required of circuit breakers used in substations and switchyards continues to increase, and currently, in 550kV systems, the circuit breaker current is up to 63kA. It has been put into practical use.

This 550 kV-63 kA class circuit breaker is constructed with four disconnect points, and in order to improve the reliability of the circuit breaker, it is important to reduce the number of disconnect points and reduce the number of parts. For this purpose, it is necessary to improve the breaking capacity per breaking point, for example, to cut Δ at 2 points or 1 point at 550 kV-63.

In order to achieve this improvement in breaking capacity, the conventional 168k
Puffer type gas circuit breakers have been used in transmission voltage systems of V or higher. This is due to the simple structure of the circuit breaker and the excellent performance of the SF6 scum used in the circuit breaker as insulation and arc extinguishing gas. In addition, in a sealed type gas-insulated switchyard where all substation equipment is insulated with SF6 gas, the insulating gas used for the circuit breaker is the same as the insulating gas used for other equipment. It is particularly widely used because it allows insulation coordination with equipment and is efficient in terms of equipment placement.

FIG. 5 shows the structure of a conventionally used puffer type gas circuit breaker. That is, a fixed electrode 2 and a movable electrode 3 are provided facing each other in the gas tank 1, and an insulating tube 4 is provided to cover the fixed electrode 2 and movable electrode 3. Conductors 5a and 5b are connected to the fixed electrode 2 and the movable electrode 3, respectively, and a drive mechanism 6 is further connected to the movable electrode 3. Furthermore, the movable electrode 3 is supported by the gas tank 1 via a supporting insulating cylinder 7.

Details of the arc extinguishing chamber of such a puffer type gas circuit breaker are shown in FIG.

In FIG. 6, the fixed electrode 2 includes a central fixed arc electrode 8 and a cylindrical fixed current-carrying contact 9 provided on the outside thereof.
A fixed shield 10 is formed on the outer periphery of the tip of the fixed current-carrying contact 9.

On the other hand, the movable electrode 3 includes a buff 7 piston 11 fixed to the drive mechanism 7 side of the gas tank 1, a puffer cylinder 12 that is provided outside the buff 7 piston 11 and slides on the outer peripheral surface of the buff 7 pistons 1 to 11, and In order to connect the puffer cylinder 12 and the drive mechanism 7, an operating rod 13 inserted into the inside of the puffer piston 11 is provided. At the tip of the puffer cylinder 12, there is an arc finger 14 that contacts the fixed arc electrode 8, and an insulating nozzle 15 that surrounds it.
is provided. The insulating nozzle 15 is held down by a movable current-carrying contact 16, and the movable current-carrying contact 16 has a movable shield 17 at its tip.

In the gas circuit breaker configured in this manner, when the operating rod 13 is reciprocated by the drive mechanism 7, the movable electrode 3
opens and closes between the stationary electrode 2 and the fixed electrode 2 facing each other to cut off the current.

Here, FIG. 6 shows a state in which the interrupting operation is in progress, and in this state, an arc 18 is generated between the fixed arc electrode 8 and the arc finger 14. Then, as the shutoff operation further progresses and the puffer cylinder 12 moves in the left-right direction, the arc-extinguishing gas is compressed in the puffer chamber 19 formed by the puffer cylinder 12 and the puffer piston 11. The puffer cylinder 19 blows out a high-speed gas flow through the hole 20 and the inner space of the insulating nozzle 15, extinguishing the arc 18.

However, in the puffer type gas circuit breaker as explained above, if the number of breaking points of the circuit breaker is reduced, the transient recovery voltage after current interruption becomes very high, such as early or delayed small current interruption, and The electric field strength generated between the poles per point on the device increases. Therefore, a problem has arisen in that the probability of re-ignition and re-ignition is high in response to a very high transient recovery voltage. Furthermore, when re-igniting and re-igniting, the arc does not occur between the arc electrodes 8 and 14, but between the fixed arc electrode 8 and the movable current-carrying contact 16, or between the fixed shield 10 and the movable current-carrying contact 16. There was also the drawback that there was a high risk of this occurring.

(Problems to be Solved by the Invention) As mentioned above, in the conventional puffer type gas circuit breaker, if an attempt is made to reduce the number of breaking points, there is a high probability of re-ignition and re-ignition due to transient recovery voltage. Furthermore, due to this phenomenon, arcs are generated at locations other than between the arc electrodes.

The present invention was proposed to solve these problems, and its purpose is to prevent re-ignition and re-ignition by devising the flow of high-speed gas flow during electrode opening. It is an object of the present invention to provide a puffer type gas circuit breaker which can reliably prevent arcing, does not generate an arc anywhere other than between the north and north poles, and has greatly improved reliability.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the puffer type gas circuit breaker according to the present invention is provided with a through hole that penetrates the movable current-carrying contact. It is connected to Puffa.

With the above configuration, in the present invention, part of the arc-extinguishing gas compressed in the blow chamber during contact opening passes through the through hole of the movable current-carrying contact, and the movable current-carrying contact The insulation performance between both liquid contactors is improved because it is sprayed into the space 1 between the liquid contactor and the fixed current-carrying contactor. As a result, there is no risk of re-ignition or re-ignition even if the recovery voltage after a small current cut-off is early or late.

(Example) Hereinafter, an example of the puffer type gas circuit breaker according to the present invention will be specifically described with reference to FIGS. 1 to 4. Note that the same parts as those of the conventional Pannor type gas circuit breaker shown in FIGS. 5 and 6 are designated by the same reference numerals, and the description thereof will be omitted.

■First Example Structure of this Example FIG. 1 (A>(B) shows the on state and the off state, respectively. In FIG. 1 (A) and (B), the movable current-carrying contact 16 is The fixed current-carrying contact 9 and the contact are energized with the rated current. Fig. 2 is an enlarged sectional view showing the vicinity of this live part. As shown in the figure, the fixed current-carrying contact 9 is It is formed to have elasticity J in the radial direction, and when the poles are opened,
The inner diameter thereof is arranged so as to be smaller than the outer diameter of the movable current-carrying contact 16 and the maximum outer diameter of the movable shield 17. The curvature of the movable shield 17 is the same as that of the fixed shield 10.
It has almost the same curvature as .

On the other hand, the movable energizing contact 16 and the puffer cylinder 12 are provided with a through hole 21 that communicates with the inside of the puffer 19 in the direction of the operating axis. Spraying that communicates and releases arc-extinguishing gas [
A plurality of holes 22 are provided.

Note that the configuration other than the above is completely equivalent to the conventional configuration shown in FIGS. 5 and 6.

Functions of this embodiment The functions of this embodiment configured as described above are as follows. - That is, when the opening command is issued in the closed state shown in FIG. The child 16 separates from the fixed current-carrying contact 9, and the current flowing between the current-carrying contacts 9 and 16 is commutated to the fixed arc electrode 8 and arc finger 14, which are still in contact.

When the electrode opening operation further progresses and the fixed arc electrode 8 and the arc finger 14 are separated, an arc is generated between the electrodes 8 and 14. This arc is extinguished by blowing gas compressed in the puffer cylinder 12 through the hole and the inner space of the insulating nozzle 15.

At this time, a part of the pressurized gas is blown onto the movable shield 17 through the through hole 21 formed in the movable current-carrying contact 16 and the puffer cylinder 12, and from the hole between the fixed shield 10 and the fixed current-carrying contact 9. A high-speed gas flow is blown into the space of the area, and the focus of the area increases locally. Therefore, even if a very high recovery voltage is applied, re-ignition or re-ignition occurring between the fixed current-carrying contact 9 and the movable current-carrying contact 17 or between the fixed shield 10 and the movable current-carrying contact 17 is prevented. This makes it possible to provide a highly reliable puffer type gas circuit breaker.

■Second Embodiment The structure of this embodiment As shown in Fig. 3 (A>(B) and Fig. 4), the book 11
In one embodiment, a plurality of through holes 23 are provided in the movable current-carrying contact 16 and the insulating nozzle 15 in a direction perpendicular to the operating axis, and the through holes 23 are formed through a space inside the insulating nozzle 15. , communicates with puffer to 19. Also, at the tip of the movable shield 17 of the insulating nozzle 15,
A plurality of second through holes 24 are provided in a direction perpendicular to the operating axis. The other configurations are completely similar to the first embodiment described above.

Effects of this Embodiment In this embodiment having the above configuration, during the shutoff operation, the arc-extinguishing gas compressed in the puffer to 19 is first blown from the paruff cylinder 12 to the hole 20 and the insulating nozzle 15. The arc generated between the electrodes 8 and 14 is blown through the internal space of the electrode 8 and 14 to extinguish it. At this time, a part of the arc-extinguishing gas flows from the internal space of the insulating nozzle 15 into the first and second through holes 23 and 24 provided in the movable current-carrying contact 16 and the insulating nozzle 15, and flows into each hole. From 23.24 Fixed Shield 10. A high-speed gas flow is blown into the space between the stationary current-carrying contact 9 and the pressure there locally increases. Therefore, as in the first embodiment described above, even if a very high recovery voltage is applied, there will be no damage between the fixed current-carrying contact 9 and the movable current-carrying contact 17 or between the fixed shield 10 and the movable current-carrying contact 17. It becomes possible to prevent re-ignition or re-ignition that occurs in the above, and it is possible to provide a highly reliable puffer type gas circuit breaker.

[Effects of the Invention] As explained above, according to the present invention, by providing the movable current-carrying contact with a through hole through which a part of the arc-extinguishing gas flow passes,
By spraying a high-speed gas flow between the fixed current-carrying contact and the movable current-carrying contact, it is possible to provide a highly reliable buff 1 type gas circuit breaker that can reliably prevent re-ignition and re-ignition.

[Brief explanation of drawings]

FIGS. 1A and 1B are cross-sectional views showing the closed state and closed state of the first embodiment of the puffer type gas circuit breaker of the present invention, respectively, and FIG. 2 is an enlarged cross-sectional view of the same embodiment without showing the main parts. 3 (A>(8)) are sectional views showing the closing state and the shutoff state of the second embodiment of the puffer type gas circuit breaker of the present invention, and FIG. 4 shows the main parts of the same embodiment. Enlarged sectional view shown, No. 5
The figure is a cross-sectional view showing a conventional puffer-type gas circuit breaker, and FIG. 6 is an enlarged cross-sectional view showing essential parts of the puffer-type gas circuit breaker of FIG. DESCRIPTION OF SYMBOLS 1... Gas tank, 2... Fixed electrode, 3... Movable electrode, 4... Insulating tube, 5a, 5b... Conductor, 6...
- Drive mechanism, 7... Support insulating cylinder, 8... Fixed arc electrode, 9... Fixed current-carrying contact, 10... Fixed shield, 11... Puffer piston, 12... Puffer cylinder, 13... Operating rod, 14... Arc finger, 15... Insulating nozzle, 16... Movable energizing contact, 17... Movable shield, 18... Arc,
19... Puffer chamber, 20... Spraying hole, 21-2
4...Through hole.

Claims (5)

[Claims] (1) A container filled with arc-extinguishing gas such as SF_6 gas is equipped with a fixed electrode and a movable electrode facing each other. The fixed electrode has a fixed arc electrode in the center and a cylindrical fixed current-carrying contact on the outside. The movable electrode has an arc finger that connects and separates from the fixed arc electrode, a movable current-carrying contact that connects and separates from the fixed current-carrying contact, and an operating rod that is connected to the drive mechanism. When an arc occurs between the electrodes, arc-extinguishing gas compressed in a puffer chamber consisting of a puffer cylinder fixed integrally with an operating rod and a puffer piston fixed in a container is placed around the arc finger. A puffer type gas circuit breaker configured to extinguish an arc by blowing air from an insulated nozzle, characterized in that the movable energizing contact is provided with a through hole communicating with the puffer chamber. Gas circuit breaker. (2) The curvature of each tip of the fixed current-carrying contact and the movable current-carrying contact are approximately the same, and the tip of the fixed current-carrying contact is given elastic force, and when disconnected, its inner diameter is the same as that of the movable current-carrying contact. The puffer type gas circuit breaker according to claim 1, which is formed to be smaller than the outer diameter. (3) The movable energizing contact has a through hole formed in the direction of the operating axis, and this through hole communicates with the puffer chamber via a through hole provided in the end face of the puffer cylinder. The puffer type gas circuit breaker according to item 1. (4) The movable current-carrying contact has a through hole formed in a direction perpendicular to the operating axis, and this through hole communicates with the puffer chamber through the through hole provided in the insulating nozzle and the inner space of the insulating nozzle. A puffer type gas circuit breaker according to claim 1. (5) The insulating nozzle has, in addition to the first through hole communicating with the through hole of the movable energizing contact, a second through hole at the tip end of the movable energizing contact. Puffer type gas circuit breaker as described in section.