JPH0311790Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a puffer-type gas shield and breaker with an improved arc extinguishing chamber structure.

(Technical background of the idea and its problems) In recent years, the demand for electricity in large cities has increased significantly, and in order to supply large amounts of electricity, the transmission voltage has been increased. The power grid is the backbone of power transmission, and it is required to maintain stable power transmission with high reliability.

For this reason, high reliability is required for the circuit breakers, which are the main equipment in substations.

The structure of a conventional puffer-type gas shield and disconnector will be explained with reference to FIG. The figure shows the state of a puffer-type gas shield and disconnector in the middle of its opening operation. In a container 2 filled with an arc-extinguishing gas 1 such as SF ₆ gas, a fixed contact part 3 and a movable contact part 4 that can freely come into contact with and separate from the fixed contact part 3 are arranged in an insulating cylinder 5. , 6 are insulated and supported. Further, the fixed contact portion 3 includes a fixed arc contact 7 and a fixed current-carrying contact 8 disposed around the outer periphery of the fixed arc contact 7. On the other hand, the movable contact part 4 includes a puffer cylinder 11 in which an internal puffer piston 11C that is driven via an opening/closing link 9 and an insulating rod 10 is disposed, an insulating nozzle 12 fixed to this puffer cylinder 11, and a movable current-carrying contact 1
3. It is composed of a movable arc contactor 14.
The opening/closing link 9 is housed in an operation case 15.

The movable contact part 4 is in the position shown by the dotted line 16 when the circuit breaker is closed, and the fixed and movable energizing contacts 8 and 13 and the fixed arc contact 7 and the movable arc contact 14 are in contact with each other. There is. When a short-circuit accident occurs in the system and an opening command is given to the shield breaker drive device by a signal from an external fault detection device, first the two current-carrying contacts 8 and 13 are opened, and then both the arc contacts 7 , 14 are separated, and an arc 17 is generated between both arc contacts 7 and 14. On the other hand, at this time, the puffer chamber 1 of the puffer cylinder 11
The arc-extinguishing gas 1 in 1a is compressed. This gas 1
The arc 17 passes from the hole 11b through the flow path 18 surrounded by the insulating nozzle 12 and the movable arc contact 14.
Extinguish the arc by applying a powerful spray to it. Note that the gas flow is indicated by arrows.

Therefore, the heat generated by the arc 17 is transmitted and diffused to a position away from both the fixed and movable opening spaces, but if the insulation is restored at the current zero point, the fault current can be cut off.

In the shear breaker with the above configuration, the arc 17 between the poles at the peak value of the fault current is caused by the current and the magnetic field generated by this current in the direction of the arrow, as shown in Figure 2. receives driving force. Therefore, due to the energy generated by the curved interpolar arc 17, the arc-extinguishing gas 1 in that space, that is, between the two current-carrying contacts 8 and 13 in the direction in which the arc 17 is curved, becomes a high-temperature gas with a considerably low density. This high-temperature gas has extremely low proof strength, so if there is a strong electric field point such as a metal object in the space where the gas stays, there is a risk that local dielectric breakdown will occur at that point. This point will be explained with reference to FIG. The movable current-carrying contact 13 also serves as a holding fitting for the insulating nozzle 12, and its tip is exposed to the fixed current-carrying contact 8, which is a counter electrode, and the electric field at that portion becomes extremely strong. Therefore, if the high-temperature gas is present around this electrode, there is a risk that partial discharge A will occur at the interface due to the re-electromotive voltage after the current is interrupted, which will eventually lead to dielectric breakdown between the electrodes. It was hot.

Therefore, the arc 1 to the movable current-carrying contact 13
In order to avoid the influence of high-temperature gas and concentration of electric field caused by 7, a structure may be considered in which the movable current-carrying contact 13 is located further away from the fixed current-carrying contact 8. but,
In this case, a new drawback arises in that the electric field at the tip of the movable arc contactor 14 increases, and the shearing performance itself deteriorates.

[Purpose of invention]

SUMMARY OF THE INVENTION The object of the present invention is to eliminate the above-mentioned drawbacks and to provide a puffer-type gas shield and disconnector with excellent breakage ability and capable of preventing dielectric breakdown between a fixed current-carrying contact and a movable current-carrying contact.

[Summary of the idea]

In order to achieve the above object, in the present invention, the tip of the fixed energized contact side of the mounting member, which is arranged to fit and fix the insulated nozzle on the outside of the insulated nozzle, is connected to the insulated nozzle and the outside of the mounting member. Surround it with a predetermined gap with the placed insulating cover,
The tip of the contact placed on the outside of the insulating cover is shifted from the tip of the mounting member in the direction of separation of the cut-off part to concentrate the electric field on the mounting member, thereby making contact between the fixed current-carrying contact and the movable current-carrying contact. This improves the dielectric strength between the electrodes.

[Example of invented nozzle]

An embodiment of the present invention will be described with reference to FIG. This figure shows the detailed structure of the upper half of the movable side part.

A movable arc contact 21 is fixed to the end of the hollow rod 20. Furthermore, inside the chamber formed by attaching the puffer cylinder 22 to the rod 20, a puffer chamber 24 is formed into which a puffer piston 23, which is fixed to a fixing part (not shown), is fitted.

The puffer cylinder 22 has an opening 22a, and the puffer cylinder 22 has an opening 22a.
Then, the rod 20 moves to the right in the figure, and the puffer chamber 24 formed between the puffer pistons 23 is compressed. The arc-extinguishing gas in the puffer chamber 24 is discharged through the opening 22a.

In the puffer cylinder 22 , an insulating nozzle 26 that forms an arc-extinguishing gas flow path 25 together with the movable arc contact 21 is arranged on the outer periphery of the movable arc contact 21 . A stepped portion 26 a is provided at the middle portion of the outer surface of the insulating nozzle 26 , and a base portion 27 b of a mounting member 27 whose distal end is engaged with the stepped portion 26 a and which fits and fixes the insulating nozzle 26 inside is brought into contact with the puffer cylinder 22 . let Step portion 26 of insulating nozzle 26
a is engaged with the tip convex portion 27a of the mounting member 27, so the insulating nozzle 26 does not move to the left in the figure. Note that the convex portion 27a is the movable arc contact 21
It is located on the fixed side of the tip. Also,
The mounting member 27 is electrically connected to the movable arc contactor 21 via the puffer cylinder 22. An insulating cover 29 is arranged outside the mounting member 27 so that a space 28 is formed between the mounting member 27 and the mounting member 27 .

The inner surface of the tip 29a of the insulating cover 29 is in contact with the outer peripheral surface near the tip of the insulating nozzle 26,
The middle part of the insulating cover 29 is connected to the mounting member 27 and the space 2.
8, the base 29b of the extension is attached to the mounting member 2.
It is in contact with the base 27b of No.7. The space 28 is a small hole 29c provided near the base 29b of the insulating cover 29.
It communicates with the arc-extinguishing gas space through. Base 27b of mounting member 27 and base 2 of insulating cover 29
A movable current-carrying contact 30 is provided on the outside of 9b to fit and fix both bases 27b and 29b. In other words, the base protrusion 27c of the mounting member 27 is connected to the movable current-carrying contact 30.
The base portion 29b of the insulating cover 29 is configured to engage with the distal end convex portion 30a of the movable current-carrying contact 30, respectively. The movable current-carrying contact 30 is fixed to the puffer cylinder 22 by a bolt 31 at a portion parallel to the puffer cylinder 22. The tip of the movable current-carrying contact 30 is located further away from the fixed side portion than the tip of the movable arc contact 21 . In this way, the insulating nozzle 26, the mounting member 27, the insulating cover 28, and the movable current-carrying contact 3
0 can be integrally constructed by sequentially assembling the movable current-carrying contact 30 with the bolt 3.
1, the entire body can be fixed to the puffer cylinder 22.

Next, the operation of this embodiment will be explained.
In the closed state, the movable energizing contact 3
A good current path is formed between the 0 and the fixed current-carrying contact of the fixed side portion (not shown).

Next, in the process of transitioning to the weeping state, both current-carrying contacts are opened first, followed by the movable arc contact 21 and the fixed arc contact (not shown). As a result, an arc is generated between both arc contacts. On the other hand, the puffer cylinder 22 moves to the right in the figure due to the shatter, and the arc-extinguishing gas in the puffer chamber 24 is compressed, and the opening 22a and the flow path 25 are compressed.
through which the arc is blown. This arc-extinguishing gas becomes hot and diffuses to the outer circumference of the insulating nozzle 26. However, the tip of the mounting member 27 is protected by the dielectric strength of the insulating cover 29 and the space 28. Further, since the exposed tip of the movable current-carrying contact 30 is located in the direction in which the movable current-carrying contact 30 is separated from the top of the mounting member 27, electric field concentration at the tip of the movable current-carrying contact 30 is alleviated.

In this way, in this embodiment, the electric field concentration at the tip of the movable current-carrying contact 30 can be alleviated, and since the high-temperature gas generation position is away from the tip of the movable current-carrying contact 30, the high temperature after the current There is no partial discharge even in response to a re-electromotive voltage. Also, the insulating nozzle 26, which is subject to a lot of wear and tear due to the heat of the arc, the mounting member 27, which has little wear and tear, the insulating cover 29, and the movable current-carrying contact 30.
are divided into movable current-carrying contacts 30.
Since they are fixed in common, workability is excellent when replacing parts during maintenance and inspection. Furthermore, it is economically advantageous because single items can be replaced and it is not necessary to replace good items at the same time.

Next, another embodiment will be described with reference to FIG.

This figure shows the detailed structure of the upper half of the movable side part. A hollow rod 40 and a movable arc contact 41 attached to the tip of the rod 40 are attached to a puffer cylinder 42, and an insulating nozzle 44 is used to form a compressed gas flow path 43 between the rod 40 and the movable arc contact 41. Attach the base of the puffer cylinder 4
2. The insulating nozzle 44 is provided with a concave groove 44a in the middle part of its outer peripheral surface.
The protrusion at the tip of the mounting member 45 is engaged with the step on the base side formed by the groove 44a of No. 4. A base portion 45a of this mounting member 45 is fixed to the puffer cylinder 42 with a bolt 48. As mentioned above, since the tip convex portion 45b of the mounting member 45 engages with the opening side of the mounting member 45 of the groove 44a of the insulating nozzle 44, the insulating nozzle 44 does not move to the left in the figure, and the puffer cylinder Supported by 42. Insulated nozzle 44
One end of an insulating cover 46 made of an insulating material is fitted into the fixed portion side of the groove 44a by tight fitting.
The other side of the insulating cover 46 extends to an intermediate portion of the mounting member 45, leaving a space 47 between the outer circumferential surface of the mounting member 45 and the space 47 therebetween. Here, a current-carrying contact portion 45c is provided at an intermediate portion of the mounting member 45 so as to protrude from the outer peripheral surface of the insulating cover 46. This current-carrying contact portion 45
The space 47 is formed between the outer peripheral surface from the c end to the tip convex portion 45b and the inner peripheral surface of the insulating cover 46. This space 47 communicates with an external gas space.

During the shearing process, an arc is generated between the movable arc contact 41 and the fixed arc contact of the fixed side portion (not shown). At the same time, the compressed arc-extinguishing gas passes through the flow path 43 and is blown onto the arc to become a high-temperature gas.

This high temperature gas diffuses to the outer periphery of the insulating nozzle 44.

However, since the distal end 45b of the mounting member 45 is surrounded by the insulating cover 46 and a space 47 is provided between both 45b and 46, it has sufficient dielectric strength. In addition, the current-carrying contact portion 45 of the mounting member 45
Since point c is located on the separation side of the attachment member 45 from the tip convex portion 45b, electric field concentration is alleviated.

[Effect of idea]

As explained above, according to the present invention, a mounting member for fixing the insulating nozzle to the puffer cylinder is attached to the outer periphery of the insulating nozzle, and the mounting member is placed outside the mounting member and the tip of the mounting member is attached with a predetermined gap. An insulating cover surrounding the insulating nozzle is attached to the outer periphery of the insulating nozzle, and the current-carrying contact portion and the movable arc contact are shifted in the direction of separation of the cross section with respect to the tip of the attachment member. Since localized discharge can be prevented and dielectric breakdown due to high temperature gas after current interruption can be prevented, it is possible to provide a puffer-type gas shield breaker that can improve insulation performance and reliability.

[Brief explanation of the drawing]

Figure 1 is a structural cross-sectional view showing a conventional puffer type gas shield breaker, Figure 2 is a diagram showing the state of the arc between the poles during the current flow of the shield breaker in Figure 1, and Figure 3
The figure is a cross-sectional view showing the section of the current line after the current line is cut off.
The figure is a sectional view showing a section of a puffer-type gas shield or disconnector showing an embodiment of the present invention, and Figure 5 is a cross-sectional view of a shield of a puffer-type gas shield or disconnector showing another embodiment of the present invention. FIG. 3 is a sectional view showing a section. DESCRIPTION OF SYMBOLS 1... Arc extinguishing gas, 2... Container, 3... Fixed contact part, 4... Movable contact part, 21... Movable arc contact, 22... Puff cylinder, 26...
Insulating nozzle, 27... mounting member, 28... space,
29... Insulating cover, 41... Movable arc contactor, 42... Puff cylinder, 44... Insulating nozzle, 46... Insulating cover.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A fixed contact part and a movable contact part disposed opposite to the fixed contact part so as to be able to move toward and away from the fixed contact part are provided in a container filled with an arc-extinguishing gas, An insulated nozzle arranged to surround the movable arc contact in a device that sprays compressed gas in the Patuaa cylinder onto the arc between both contacts in conjunction with the opening and closing movement between the contacts of both contact parts. is engaged with the insulating nozzle at the middle part of its outer periphery and is fixed to the Patuaa cylinder via a mounting member whose tip is located closer to the fixed contact than the movable arc contact, and One end is fixed near the tip of the outer periphery of the insulating nozzle so as to surround the outer periphery, and the other end is attached to the mounting member and an insulating cover stretched out with a predetermined gap through which arc-extinguishing gas flows in and out. The mounting member is characterized in that a current-carrying contact portion is provided on the outer circumferential surface near the base of the mounting member, and the tip of the mounting member is located closer to the fixed contact portion than the current-carrying contact portion. Patuaa type gas disconnector. (2) The Patuaa-type gas shield disconnector according to claim 1, wherein the current-carrying contact portion is constituted by a separate member from the mounting member. (3) The Patuaa type gas shield disconnector according to claim 1, wherein the current-carrying contact portion is made of the same material as the mounting member.