JPH0743982B2 - Puffer type gas circuit breaker - Google Patents

Description

The present invention relates to a puffer type gas circuit breaker used in a substation or a switching station of an electric power system, and in particular, opening and closing of a movable contact. The present invention relates to a puffer-type gas circuit breaker capable of maintaining an initial state even when a movable energizing contactor and a fixed contactor are improved on the way and opened and closed many times.

(Prior Art) In recent years, the capacity of power plants has been increasing along with the increase in demand for electric power. Moreover, due to the difficulty in constructing a power plant in an urban area, which is a high-consumption area of electric power, the transmission line is lengthened, and the voltage tends to be increased to improve the transmission efficiency. With such large capacity and high voltage of the power transmission system, the circuit breaker capacity required for circuit breakers used in substations and switchyards has been increasing, and current circuit breaker current is 6% in 550kv system.
It has been put to practical use up to 3kA.

This 550kv-63kA class circuit breaker is composed of four points, but in order to improve the reliability of the circuit breaker, it is important to reduce the number of breaking points and the number of parts. For this purpose, it is necessary to improve the breaking capacity per breaking point, and for example, cut 550 kv-63 kA into two points or one point.

In order to achieve such improvement of the breaking capacity, a puffer type gas circuit breaker has been used in the transmission voltage system of 168 kv or more. This, on the structure of the circuit breaker is easy, is due to superior performance of the SF ₆ gas circuit breaker to be used as insulation and arc-extinguishing gas. In addition, the entire substation equipment is SF
_In a sealed gas insulated switchgear with ₆ gas insulation, the insulation gas used for the circuit breaker is the same as the insulation gas used for other equipment, so insulation coordination between the circuit breaker and other equipment is possible. It is also widely used because it is efficient in terms of equipment arrangement.

FIG. 5 shows the structure of a conventional puffer type gas circuit breaker. That is, the fixed electrode 2 and the movable electrode 3 are provided in the gas tank 1 so as to face each other, and the insulating cylinder 4 is provided so as to cover the fixed electrode 2 and the 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 connected to the movable electrode 3. Further, 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 is composed of a fixed arc electrode 8 at the center and a cylindrical fixed energizing contact 9 provided outside the fixed arc electrode 8.
A fixed shield 10 is formed on the outer circumference of the tip of the fixed energizing contact 9. On the other hand, the movable electrode 3 is a puffer piston 11 fixed to the drive mechanism 7 side of the gas tank 1.
And a puffer cylinder 12 provided outside thereof and sliding on the outer peripheral surface of the puffer piston 11, and an operating rod 13 inserted into the puffer piston 11 for connecting the puffer cylinder 12 and the drive mechanism 7. It has and.
At the tip of the puffer cylinder 12, an arc finger 14 that contacts the fixed arc electrode 8 and an insulating nozzle 15 that surrounds the arc finger 14 are provided. The insulating nozzle 15 is pressed by a movable energizing contact 16, and the movable energizing contact 16 has a movable shield 17 at its tip.

In the gas circuit breaker configured in this way, the operating rod
When the drive mechanism 7 reciprocates the movable electrode 13, the movable electrode 3 opens and closes between the movable electrode 3 and the fixed electrode 2 facing the movable electrode 3 to interrupt the current.

Here, FIG. 6 shows a state during the breaking operation, and in this state, the fixed arc electrode 8 and the arc finger are
An arc 18 occurs between 14 and. When the shutoff operation further proceeds and the puffer cylinder 12 moves in the left-right direction, and the arc extinguishing gas is compressed in the puffer chamber 19 formed by the puffer cylinder 12 and the puffer piston 11, this arc extinguishing gas is generated. A high-speed gas flow is blown out through the blowing holes 20 of the puffer cylinder 19 and the inner space of the insulating nozzle 15 to extinguish the arc 18.

However, as explained above, in the puffer type gas circuit breaker, if the number of circuit breaker points is reduced, the transient recovery voltage after current circuit breakage becomes very high, as in the case of leading or delayed small current circuit breaker, and the circuit breaker breaks. The electric field strength generated between the poles per point of the container increases. Therefore, there has been a problem that the probability of re-ignition and re-ignition increases with a very high transient recovery voltage. Furthermore, when re-ignition and re-ignition, the arc does not occur between the arc electrodes 8 and 14,
There is also a drawback that the risk of occurring between the fixed arc electrode 8 and the movable energizing contactor 16 or between the fixed shield 10 and the movable energizing contactor 16 increases.

(Problems to be Solved by the Invention) As described above, in the conventional puffer-type gas circuit breaker, if the number of breaking points is reduced, the probability of re-ignition and ignition to the transient recovery voltage increases. Further, there is a problem that an arc is generated at a place other than between the arc electrodes due to this phenomenon.

The present invention has been proposed in order to solve such a problem, and an object thereof is to surely prevent re-ignition and re-ignition by devising a flow of a high-speed gas flow during opening. It is possible to provide a puffer-type gas circuit breaker with significantly improved reliability without generating an arc in a place other than between the arc electrodes.

[Configuration 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 energizing contact, and the through hole is formed. It communicates with the puffer room.

(Operation) With the above-described configuration, in the present invention, a part of the arc-extinguishing gas compressed in the puffer chamber at the midway of the interelectrode passes through the through hole of the movable energizing contact to cause the movable energizing contact. Since it is sprayed into the space between the child and the fixed current-carrying contact, the insulation performance between both contacts is improved. As a result, there is no risk of re-ignition or re-ignition even if the recovery voltage after the advance or delay small current interruption is high.

(Embodiment) Hereinafter, an embodiment of the puffer type gas circuit breaker according to the present invention will be specifically described with reference to FIGS. 1 to 4. The same parts as those of the conventional puffer 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 Embodiment * Structure of Embodiments FIGS. 1A and 1B show a closed state and a closed state, respectively. In FIGS. 1 (A) and 1 (B), the movable energizing contact 16 is energized with the fixed energizing contact 9 and the contact, and the rated current. FIG. 2 is an enlarged sectional view showing the periphery of the energizing portion. As shown in the figure, the fixed energization contactor 9 is formed so as to have an elastic force in the radial direction, and when the contact is opened, the inner diameter dimension thereof is the outer diameter dimension of the movable energization contact element 16 and the maximum of the movable shield 17. It is arranged to be smaller than the outer diameter.
The curvature of the movable shield 17 has substantially the same curvature as the curvature of the fixed shield 10.

On the other hand, a through hole 21 communicating with the inside of the puffer chamber 19 is provided in the movable energizing contact 16 and the puffer cylinder 12 in the operation axis direction, and a through hole is formed at the tip of the movable shield 17.
A plurality of spray holes 22 communicating with 21 and discharging arc extinguishing gas are provided.

It should be noted that the configuration other than the above is completely equivalent to the conventional configuration shown in FIGS. 5 and 6.

* Operation of the embodiment The operation of the present embodiment configured as described above is as follows.

That is, in the closed state of FIG. 1 (A), when the contact opening command is issued, the drive mechanism is driven and the operation rod 13 starts operating in the right direction in the figure. By this operation, the movable energizing contact 16 is first separated from the fixed energizing contactor 9, and the energizing contactor
The current that has been applied between 9 and 16 commutates to the fixed arc electrode 8 and the arc finger 14 that are still in contact.

When the electrode opening operation further proceeds and the fixed arc electrode 8 and the arc finger 14 are separated, an arc is generated between the electrodes 8 and 14. The gas compressed in the puffer chamber 19 is blown to the arc through the blowing hole of the puffer cylinder 12 and the inner space of the insulating nozzle 15 to extinguish the arc. At this time, a part of the pressurized gas partially moves the movable energizing contact 16 and the puffer cylinder 12.
A high-speed gas flow is blown into the space between the fixed shield 10 and the fixed energizing contact 9 from the blowing hole of the movable shield 17 through the through hole 21 formed in the. Rise. Therefore, even if a very high recovery voltage is applied, the recurrence or re-ignition that occurs between the fixed energizing contact 9 and the movable energizing contact 17 or between the fixed shield 10 and the moving energizing contact 17 is prevented. Therefore, it is possible to provide a highly reliable puffer type gas circuit breaker.

Second Embodiment * Configuration of the Embodiment As shown in FIGS. 3 (A), (B) and FIG. 4, in this embodiment, the movable energizing contact 16 and the insulating nozzle 15 are orthogonal to the operating axis. A plurality of through holes 23 are provided in the direction, and the through holes 23 are provided through the space inside the insulating nozzle 15,
It communicates with the puffer room 19. Further, a plurality of second through holes 24 are provided in the tip portion of the insulating nozzle 15 beyond the movable shield 17 in the direction orthogonal to the operation axis. The other structure is the same as that of the first embodiment.

* Operation of the embodiment In the present embodiment having the above-described structure, the arc-extinguishing gas compressed in the puffer chamber 19 at the time of the shut-off operation first flows into the spray hole 20 of the puffer cylinder 12 and the insulating nozzle 15. The arc generated between both electrodes 8 and 14 is sprayed through the internal space to extinguish the arc. At this time, 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 energizing contact 16 and the insulating nozzle 15, and the holes A high-speed gas flow is blown into the space between 23, 24 and the fixed shield 10 and the fixed energization contactor 9, and the pressure in the same part rises extremely. Therefore, similar to the first embodiment described above, even when a very high recovery voltage is applied, the gap between the fixed energizing contact 9 and the movable energizing contact 17 or between the fixed shield 10 and the moving energizing contact 17 is increased. It is possible to prevent the re-ignition or the re-ignition that occurs in 1. and to provide a highly reliable puffer type gas circuit breaker.

[Effects of the Invention] As described above, according to the present embodiment, the movable energizing contactor is provided with the through hole that allows a part of the arc-extinguishing gas flow to pass therethrough. It is possible to provide a highly reliable puffer type gas circuit breaker capable of reliably preventing re-ignition and re-ignition by blowing a high-speed gas flow between the gas circuit breakers.

[Brief description of drawings]

FIGS. 1 (A) and 1 (B) are sectional views showing a puffer type gas circuit breaker of the present invention in a closed state and a closed state, respectively, and FIG. 2 is an enlarged sectional view showing an essential part of the same example. 3 (A) and 3 (B) are sectional views showing the puffer type gas circuit breaker of the present invention in a closed state and a closed state, respectively, and FIG. 4 is an enlarged cross-sectional view showing the main part of the same embodiment. Figure, fifth
FIG. 6 is a sectional view showing a conventional puffer type gas circuit breaker, and FIG. 6 is an enlarged sectional view showing a main part of the puffer type gas circuit breaker of FIG. 1 ... gas tank, 2 ... fixed electrode, 3 ... movable electrode,
4 ... Insulation cylinder, 5a, 5b ... Conductor, 6 ... Drive mechanism, 7 ...
… Supporting insulating cylinder, 8… Fixed arc electrode, 9… Fixed energizing contact, 10… Fixed shield, 11… Puffer piston, 12… Puffer cylinder, 13… Operation rod, 14…
… Arc finger, 15 …… insulation nozzle, 16 …… moving energizing contact, 17 …… moving shield, 18 …… arc, 19 ……
Puffer chamber, 20 ... Blowing holes, 21-24 ... Through holes.

Claims (5)

[Claims] 1. A container filled with an arc extinguishing gas such as SF ₆ gas is provided with a fixed electrode and a movable electrode facing each other, and the fixed electrode is
A fixed arc electrode at the center, each having a cylindrical fixed current-carrying contactor on the outside thereof, the movable electrode, an arc finger contacting and separating from the fixed arc electrode, a movable current-carrying contactor contacting and separating from the fixed current-carrying contactor, And a control rod connected to the drive mechanism, and is composed of a puffer cylinder fixed integrally with the control rod and a puffer piston fixed in the container when an arc is generated between the arc electrodes due to the breaking operation. Arc-extinguishing gas compressed in the puffer chamber, in a puffer-type gas circuit breaker configured to extinguish the arc by blowing out from an insulating nozzle provided around the arc finger, in the movable energizing contact, A puffer type gas circuit breaker having a through hole communicating with the puffer chamber. 2. The fixed current-carrying contactor and the movable current-carrying contactor have substantially equal curvatures at their tips, and the tip of the fixed current-carrying contactor has elastic force and its inner diameter is movable when the circuit is cut off. The puffer type gas circuit breaker according to claim 1, wherein the puffer type gas circuit breaker is formed so as to be smaller than the outer diameter of the child. 3. A movable energization contactor is formed with a through hole in the operation axis direction, and this through hole communicates with the puffer chamber through the through hole provided in the end surface of the puffer cylinder. A puffer type gas circuit breaker according to claim 1. 4. A movable current-carrying contact is formed with a through hole in a direction orthogonal to an operation axis, and the through hole is provided in a puffer chamber through a through hole provided in the insulating nozzle and an inner space of the insulating nozzle. The puffer type gas circuit breaker according to claim 1, which is in communication with each other. 5. The insulating nozzle has, in addition to the first through hole communicating with the through hole of the movable current-carrying contact, a second through-hole at the tip of the movable current-carrying contactor. The puffer type gas circuit breaker according to item 4.