JPS63284728A - Vacuum valve with trigger discharge device - Google Patents

Abstract

PURPOSE:To prevent a trigger section from being short-circuited with metal grains and improve the life and reliability by providing projections on mating electrodes at positions apart from a trigger discharge device. CONSTITUTION:A trigger shaft 13 is fitted to the inside of a trigger insulating cylinder 12, and a trigger pin 14 is provided on its end face. A projection 20a is provided on the outer periphery of the face of a fixed electrode 20 facing a movable electrode 21, a step is formed between the trigger pin 14 and the face of the fixed electrode 20 near it, a projection 21a is likewise provided on the outer periphery side of the face of the movable electrode 21 facing the fixed electrode 20. If a trigger type vacuum valve is used as a closing unit, arcs are moved to the outer periphery side of the fixed electrode 20 just before the movable electrode 21 is brought into contact with the fixed electrode 20 and are not concentrated locally near the trigger pin 14 at the center. A trouble that the trigger pin 14 and the fixed electrode 20 are short-circuited with the molten metal is thereby prevented, and the life and reliability can be improved.

Description

[Detailed description of the invention] [Object of the invention] (Industrial application field) The present invention relates to a true chamber valve equipped with a trigger discharge device,
In particular, the present invention relates to an improvement in the electrode section of a vacuum valve equipped with a trigger discharge device used in a closing device for short-circuiting and grounding fault current in a power distribution system.

(Prior art) Vacuum valves, which are constructed by arranging a pair of detachable electrodes in a vacuum container made of an insulating cylinder made of ceramic or the like and having both openings closed with metal end plates, are used in a variety of applications. has been done. Especially its characteristics. It has many advantages such as high dielectric strength, good interrupting performance, and long life, and its range of applications is expanding. Recently, it is sometimes used as a closing device for protecting against fault current6.As a closing device for protecting against fault current requires a quick closing time, a trigger electrode, which is the third electrode, is arranged. In some cases, a vacuum valve equipped with a trigger discharge device (hereinafter referred to as a trigger-type vacuum valve) is used. This trigger-type vacuum valve can short-circuit the main electrodes more quickly than a commonly used mechanical input device because of the energy discharged between the trigger electrode and the main electrode.

Therefore, for example, when used as a switch for short-circuiting and grounding a fault current in a distribution line, etc., the short-circuit current can shorten the energization time of the distribution line, etc., and the current capacity of the distribution line, etc. can be reduced. .

FIG. 8 shows a conventional trigger type vacuum valve 1. As shown in FIG.

This vacuum valve 1 has an insulating cylinder 2 made of ceramic or the like, and airtightly closes the openings at both ends with end plates 3 and 4 to form a vacuum container 5. A fixed electrode 6 and a movable electrode 7 forming possible electrodes are arranged. The fixed electrode 6 and the movable electrode 7 are connected to a current-carrying shaft 8, respectively.
It is electrically and mechanically connected to the outside of the vacuum container 5 via 9. The current-carrying shaft 9 on the side of the movable electrode 7 is hermetically connected to the end plate 4 via a bellows 10, and while maintaining a high vacuum in the vacuum container 5, the electrode part is connected and separated by an operation mechanism (not shown). is possible.

An arc shield 11 is disposed around the electrode portion in order to prevent the inner surface of the insulating cylinder 2 from being contaminated and the dielectric strength from decreasing due to metal vapor generated between the electrodes.

A through hole is provided in the center of the fixed electrode 6 and the current-carrying shaft 8 on the fixed side, and a trigger insulating cylinder 12 made of ceramic or the like is provided.
is located. A trigger shaft 13 is arranged inside the trigger insulating cylinder I2, and a trigger pin 14 is arranged at one end of the trigger shaft 13.
, a trigger terminal 15 is electrically connected to the other end. The end surface of the trigger insulating cylinder 12 on the atmosphere side is hermetically connected to the trigger terminal 15 . Further, the outer circumferential surface of the insulating trigger cylinder 12 is hermetically connected to the fixed current-carrying shaft 8 . The hermetic connection may be formed of a metal having a coefficient of thermal expansion close to that of the trigger insulating cylinder 12, and may be airtightly connected via a seal ring (not shown).

Further, the vacuum side end surface of the trigger insulating cylinder 12 is arranged so as to be in contact with the central hole of the fixed electrode 6 and the trigger pin 14 . In other words, the trigger pin 14 and the fixed electrode 6
and are electrically insulated by the creeping edge of the trigger insulating cylinder 12.

The trigger type vacuum valve 1 configured as described above is incorporated into an operating mechanism, for example, an operating mechanism for a vacuum circuit breaker, and is operated. When used in a circuit where a fault current is caused by a three-phase short circuit and grounding, the fixed electrode 6 side is used as the grounding side. When performing the closing operation, first, a high voltage is applied between the trigger terminal 15 and the fixed defecation electrode 8, and a discharge is generated between the trigger pin 14 and the fixed electrode 6. The location where the discharge occurs is
The vacuum side end face of the trigger insulating cylinder 12 (trigger pin around 13).

The energy generated by this discharge causes a flash between the main electrodes, causing the trigger-type vacuum valve to become conductive.

Short circuit is closed. However, since the arc extinguishing ability is high in a vacuum, when used in an AC circuit, the arc may be extinguished at the current zero point, causing a short circuit current to flow into the main system. In order to prevent this, the main electrode of the trigger type vacuum valve may be turned on and used using the operating mechanism.

(Problems to be Solved by the Invention) The structure described above has the following problems.

When the trigger type vacuum valve 1 is assembled into an operating mechanism and used for closing operation and for short-term application of fault current, the movable electrode 7 is driven by the operating mechanism, and the fixed electrode 6
Immediately before contact is made with the fixed electrode 6, the arc locally concentrates in the center of the fixed electrode 6 (near the trigger pin 14), and the fixed electrode 6 is brought into contact with the fixed electrode 6. This not only causes local damage to the pole 6 but also promotes the generation of metal particles. In some cases, these metal particles scatter into the trigger space 16 and short-circuit the trigger pin 14 and the fixed electrode 6, which may impair the trigger function and reduce the lifespan and reliability of the trigger-type vacuum valve 1. There were times when I was forced to do so.

The present invention has been made in view of the above problems.

The aim is to improve the life and reliability of triggered vacuum valves.

[Structure of the invention]

(Means for Solving the Problems) The present invention forms a vacuum container by closing the openings at both ends of an insulating cylinder with end plates, and a pair of electrodes that can be freely moved toward and away from the vacuum container are disposed inside the vacuum container. In a vacuum bulb equipped with a trigger discharge device on at least one of the electrodes, a convex portion is provided on the w1 pole at a position away from the trigger discharge device and on the side of the other electrode facing the trigger discharge device. .

(Function) Immediately before the pair of electrodes come into contact, the arc is moved to the convex side to eliminate the concentration of the arc on the trigger part, prevent the trigger part from shorting due to metal particles, and improve life and reliability. .

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. Regarding vacuum containers, arc shields, bellows, etc.
The 6th 111th configuration is the same as the conventional one, so the explanation will be omitted.
In 1, a fixed electrode 20 constituting a pair of electrodes that can be moved in and out of the vacuum chamber (not shown) is installed. The movable electrodes 21 are arranged facing each other, and the fixed electrode 20 and the movable electrode 21 are mechanically and electrically connected to the outside of the vacuum vessel via current-carrying shafts 8 and 9, respectively. A through hole is provided in the center of the fixed electrode 209 and the energizing shaft 8, and a trigger insulating cylinder 12 is inserted into this through hole.
is installed. A trigger shaft 13 is attached to the inside of this trigger insulating cylinder 12, and a trigger pin 14 is attached to the @ side of the trigger shaft 13.
is provided. Here, the end surface of the trigger insulating cylinder 12 is arranged so as to be in close contact with the fixed electrode 20 and the trigger bin 14.

Further, the fixed electrode 20 is provided with a convex portion 20a on the outer peripheral side of the surface facing the movable electrode 21, forming a step with the trigger bin 14 and the surface of the fixed electrode 20 in the vicinity thereof.

Similarly, a convex portion 21a is also provided on the outer peripheral side of the surface of the movable electrode 21 facing the fixed electrode 2o. Note that, depending on the magnitude of the fault current to be applied, the movable electrode 21 may have a planar structure without providing the convex portion 21a.

Next, the operation of the trigger type vacuum valve configured as above will be explained. A trigger type vacuum valve is incorporated into the operating mechanism, and the fixed electrode 20 side is connected to the ground side. Note that the fixed electrode 20 and the movable electrode 21 are in a separated state. When a fault current in the system is detected, a high voltage is applied between the trigger terminal 15 and the current-carrying shaft 8 at the same time as starting the driving of the operating mechanism.

Here, the trigger shaft 13 and the trigger bin 14 are electrically at the same potential, and the current-carrying shaft 8 and the fixed electrode 20 are electrically at the same potential.

When a high voltage is applied between the trigger terminal 15 and the current-carrying shaft 8, the trigger pin 14. Preliminary discharge begins due to creeping discharge in the small gap between the fixed electrodes 20, and plasma generated in this area flows into the fixed electrodes 20. Injected between the movable electrodes 21,
During this time, the withstand voltage decreased.

Fixed electrode 20. The arc causes a flash between the movable electrodes 21. Even during this arc generation period, the movable electrode 21
continues to be driven to approach the fixed electrode 21. When the trigger fires, the fixed electrode 20. The arc existing between the movable electrodes 21 is moved between the fixed electrodes 20 and 20 by the movable electrodes 21 that continue to be driven. When the gap length between the movable electrodes 21 becomes smaller, the convex portion 20a of the fixed electrode 20 and the convex portion 21 of the movable electrode 21
Shifts to part a, maintains the discharge only in this part, and finally the convex part 2°a of the fixed voltage w420, the movable part 1! f! i21
The closing operation is completed by the contact of the convex portion 21a.

Therefore, according to one or more configurations, when a trigger type vacuum valve is used as a dosing device, the movable electrode 21 is replaced by the fixed electrode 21.
This is because the arc moves to the outer circumferential side of the fixed electrode 20 immediately before it is brought into contact with the fixed electrode 20, and is not locally concentrated near the trigger bin 14 in the center.

The problem of short-circuiting the trigger bin 14 and the fixed electrode 20 due to molten metal is eliminated, and the life and reliability can be improved.

Note that the present invention is not limited to the above-described embodiment (hereinafter referred to as the first embodiment), and can be implemented in various modifications. That is, in FIGS. 2 and 3, a trigger discharge device and a convex portion 22ati having the same structure as in the first embodiment are provided at the center and outer circumferential sides of the fixed electrode 22, respectively, and a spiral groove is provided throughout the fixed electrode 22. This fixed electrode 22 shows an embodiment (hereinafter referred to as the second embodiment) in which a plurality of fixed electrodes 23 are provided.
A movable electrode (not shown) disposed opposite to is also provided with a convex portion and a spiral groove. FIG. 4 shows the fixed electrode 24
An embodiment (hereinafter referred to as the third embodiment) is shown in which a cup shape with a bottom is provided, a plurality of grooves 25 are provided on the side surface, and a trigger discharge device having the same configuration as the first embodiment is provided in the center.
The movable electrode (not shown) disposed opposite to the fixed electrode 24 is also shaped like a cup with a bottom, and a plurality of similar grooves are provided on the side surface of the movable electrode. The main electrode uses a magnetic drive method. Fifth
The figure shows an embodiment (hereinafter referred to as "vertical magnetic field configuration") in which a coil electrode 26 for applying an axial magnetic field to the arc (so-called vertical magnetic field configuration) is provided on the back side of a fixed electrode 25 having a configuration substantially similar to that of the first embodiment.

1 energizing shaft 8 is a coil electrode 26
It is connected to the fixed electrode 25 via. This fixed electrode 25
The second, third, and fourth embodiments described above, in which a coil electrode is also provided on a movable electrode (not shown) disposed opposite to the movable electrode (not shown), can cope with relatively large fault currents. It is something.

In FIG. 6, a convex portion 27a is provided at the center of the fixed electrode 27, a ring-shaped trigger bin 29 is arranged on the outer peripheral surface of the fixed electrode 27 via a trigger space 28, and the trigger bin 29 is connected to a hollow trigger shaft. 30, and an insulating trigger cylinder 31 and a round bar-shaped current-carrying shaft 32 are arranged inside the trigger shaft 30 (hereinafter referred to as the fifth embodiment). A convex portion 33a is provided. Reference numeral 34 indicates an energizing axis of the movable electrode 33. FIG. 7 shows that a fl
An embodiment (hereinafter referred to as the sixth embodiment) is shown in which a coil electrode 36 having the same function as the S4 embodiment is provided, and one energizing shaft 32 is connected to a fixed electrode 35 via the coil electrode 36. A movable electrode (not shown) disposed opposite to the fixed electrode 35 is also provided with a coil electrode.

In each of the embodiments described above, a trigger discharge device is provided on the fixed electrode, but a similar trigger discharge device may also be provided on the movable electrode. Although it was formed.

Separately manufactured parts may be fixed together by brazing or other means.

〔Effect of the invention〕

Since the present invention is configured as described above, it is possible to eliminate the problem of the trigger section being short-circuited by molten metal when the main electrode is inserted, and to provide a vacuum valve equipped with a trigger device that has significantly improved lifespan and reliability. can be provided.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a main part of one embodiment of the present invention, and FIG. 2 is a sectional view showing a main part of another embodiment of the invention. FIG. 3 is a plan view of FIG. 2, FIG. 4 is a sectional view showing the main parts of another embodiment of the present invention, and FIG. 5 shows the main parts of another embodiment of the invention. 6 is a sectional view showing a main part of another embodiment of the present invention, FIG. 7 is a sectional view showing a main part of another embodiment of the invention, and FIG. 8 is a sectional view showing a main part of another embodiment of the present invention. FIG. 3 is a sectional view of a vacuum valve with a trigger device; 5... Vacuum container 8, 9... Current-carrying shaft 12.
...Trigger insulating tube 13...Trigger shaft 14...
Trigger bin 16...Trigger space 20...Fixed electrodes 20a, 21a...Protrusion 21...
Movable electrode (8733) Agent Patent attorney Yoshiaki Inomata (and 1 other person) Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 8

Claims (3)

[Claims] (1) A vacuum container is formed by closing the openings at both ends of an insulating cylinder with end plates, and a pair of electrodes that can be freely moved toward and away from the vacuum container is disposed inside the vacuum container, and a trigger discharge is applied to at least one of the electrodes. 1. A vacuum valve equipped with a trigger discharge device, characterized in that the electrode is provided with a convex portion at a position away from the trigger discharge device and on the other electrode side facing the trigger discharge device. (2) A vacuum valve equipped with the trigger discharge device according to claim 1, wherein the electrode is provided with a groove for magnetically driving an arc. (3) A vacuum valve equipped with a trigger discharge device according to claim 1, wherein a coil electrode is provided on the back surface of the electrode to provide an axial magnetic field to the arc.