JPH10308143A - Main circuit disconnector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a main circuit disconnector capable of keeping the voltage proof characteristic without increasing the space occupied by the insulation. SOLUTION: A shaft part 3a of a movable shield 3 is pierced in the center of a contact base 1. A return spring 5 is freely fitted around the shaft part 3a of the movable shield 3, and its forward end is fitted to a back side of a head part 3b formed on the forward end of the movable shield 3, and its rear end is fitted to a projected part 1c of a bottom part of the contact base 1. A spring pin 16 is press-fitted to the rear end of the shaft part 3a of the movable shield 3 to position the return spring 5 in the returned condition. In a condition where the head part 3b of the movable shield 3 is returned, a forward end face is slightly projected from a forward end face of a shield 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a main circuit disconnector incorporated in a gas-insulated metal closed switchgear or the like.

[0002]

2. Description of the Related Art FIG. 3 is a right side view showing an example of a conventional gas-insulated metal switchgear in which a main circuit disconnector is incorporated (however, a right side plate is omitted). FIG.

In FIG. 3, a partition 21a for vertically gas-separating the metal box 21 is provided in the middle of the metal box 21 having a sealed structure and slightly forward (to the left in the drawing). This partition 21
A partition 21c is also provided vertically behind a, and as a result, a low-pressure chamber 31A is formed in front of the partition 21a.

[0004] Between the front and rear partitions 21a and 21c, there is a horizontal partition 21b which vertically separates the space between these partitions 21a and 21c.
Are provided above the partition 21b to form a disconnector chamber 31B, and below the partition 21b, a circuit breaker chamber 31C is formed. Of these, the disconnector chamber 31B and the circuit breaker chamber 31C are filled with sulfur hexafluoride gas (SF ₆ gas) as an insulating gas.

[0005] Three insulating bushings 27 are provided through the ceiling of the disconnector chamber 31B. A three-phase disconnector 24A is hermetically provided at the upper end of the partition 21a, and the upper pole of the disconnector 24A is connected to the lower end of the insulating bushing 27 by a conductor.

A grounding disconnector, which is not described in detail, is incorporated above the disconnecting portion 24a of the disconnector 24A. The disconnecting switch 24A is a disconnector with a grounding device. The lower end of the disconnecting portion 24a
It is connected to the upper end of an insulating spacer 28 penetrating the partition 21b.

At the upper end of the circuit breaker chamber 31C, a vacuum circuit breaker 25 is provided to penetrate the partition 21a back and forth. The upper end of the main circuit portion 22 of the vacuum circuit breaker 25 is connected to the lower end of the insulating spacer 28 by a conductor.

Under the vacuum circuit breaker 25, a disconnector 24B is provided through the partition 21a, and the upper pole of the disconnector 24B is connected to a conductor 32A.
Is connected to the lower end of the main circuit section 22 of the vacuum circuit breaker 25 via the. A grounding disconnector is also incorporated below the disconnecting portion of the disconnector 24B.

A lightning arrester 23 is provided below the disconnector 24B.
a. A pair of mounting plates 33 are provided on the front surface of the partition wall 21c with respect to the breaker room 31C, and three main circuit conductors 32B are fixed to the front surfaces of these mounting plates 33 via support insulators 34. Have been. The lower portion of the main circuit conductor 32B curves forward and is connected to the lower pole of the disconnector 24B.

A connecting conductor is provided at the lower end of the main circuit conductor 32B.
3 is connected to the front surface of the lower end of the connection conductor 11 as shown in FIG.
A disconnector 14, which will be described later and shown in FIG.

A cable head 29 is provided at an intermediate portion of the partition 21c.
Is attached from the cable room 31D side, and the main circuit conductor 32B
The front end is connected to the upper end of. This cable head 29
The lower end is connected to the upper end of a high-pressure cross-linked polyethylene cable 30 raised from a cable pit formed on the floor where the metal box 21 is installed.

At the lower end of the cable chamber 31D, a through-type current transformer 26 fixed to the partition 21c is shown. At the front end of the metal box 21, a front door 21d is shown. Shows a rear door 21e.

In FIG. 4, a disk-shaped contact base 13 in a front view (not shown) is fixed to the front surface of the connection conductor 11 with bolts 15. An arc-shaped groove is formed on the outer periphery of the cylindrical portion 13a protruding from the front surface of the contact base 13.

The contacts 4 are arranged in an annular shape on the outer periphery of the cylindrical portion 13a, and the arc-shaped convex portions formed on the opposite side of the rear portion of the contacts 4 are formed on the outer periphery of the cylindrical portion 13a. It is fitted in the groove.

At the center of the outer surface of the annularly arranged contact 4, there is inserted a spacing ring 7 having an irregular shape formed on the inner periphery thereof. The formed coil spring 6 is wound with tension applied.

The rear end of the shield 2 for reducing the electric field, which has been drawn into a substantially hemispherical shape, is fitted to the outer periphery of the bottom of the contact base 13 and is fixed with a plurality of flat head screws (not shown). A through hole is formed in the center of the shield 2, and the rear part of the disconnecting rod 10 of the lightning arrester 23 is shown fitted in this through hole.

The reason why the shape of the shield 2 is formed in a hemispherical shape is that, as disclosed in Japanese Patent Application Laid-Open No. 60-128807, the insulation breakdown voltage of the insulating gas is reduced by the electric field near the outer periphery of the high-voltage charged portion. This is because it greatly affects the strength.

[0018]

However, in the main circuit disconnector constructed as described above, when the disconnecting rod 10 of the lightning arrester 23 is pulled forward for the withstand voltage test of the metal-closed switchgear. Since the electric field strength of the insulating gas atmosphere near the inner periphery of the through hole formed at the center of the shield 2 is increased, the withstand voltage characteristic between the lightning arrester 23 and the rear end of the disconnecting rod 10 may be reduced. .

Therefore, it is conceivable to increase the stroke of the disconnecting rod 10 by increasing the distance between the rear end of the lightning arrester 23 and the main circuit disconnector. However, the mounting position of the main circuit disconnector is moved backward accordingly. So you have to
The position of 21c must also be moved backward.

Then, since the depth of the box increases accordingly, the floor area of the power receiving equipment required for installing the box also increases, and the features of the gas insulated metal closed switchgear, which reduces the installation floor area. Impair. Therefore, an object of the present invention is to provide a main circuit disconnector capable of maintaining a withstand voltage characteristic without increasing the insulation occupied space.

[0021]

According to a first aspect of the present invention, there is provided a main circuit disconnector in which a contact portion into which an end of a disconnecting rod operated in an axial direction is inserted and removed is connected to a conductor fixed to the main circuit conductor. The movable shield, which is mounted, retracts from the contact portion by the operation of inserting the disconnecting rod, returns by the operation of removing the disconnecting rod, and closes the opening of the concave portion, is loosely fitted into the concave portion of the shield.

In addition, in particular, the main circuit disconnector of the invention according to claim 2 has a contact portion which is a ring-shaped contact on the outer periphery of the contact base and is provided on the outer periphery of the contact base and the contact. A shield tube having a U-shaped cross section is used as a shield.

In particular, the main circuit disconnector of the invention according to claim 3 comprises a conductor and a shield formed by a substantially hemispherical contact block having a U-shaped cross section, and a concave portion having a U-shaped cross section of the contact block. The contact plate is mounted on the contact plate. Furthermore, in particular, the main circuit disconnector of the invention according to claim 4 is characterized in that a rear shield in which a rear portion of the movable shield is retracted is provided behind the main circuit conductor.

With such a means, in the present invention, an increase in the electric field strength in the space at the opening end of the concave portion of the shield caused by the disconnection operation of the disconnecting rod is eliminated by the movable shield closing the opening end.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the main circuit disconnector of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing a first embodiment of a main circuit disconnector according to the present invention, which corresponds to FIG. 4 shown in the prior art, and in particular, corresponds to claim 2; Indicates a disconnected state.

In FIG. 1, the difference from the disconnector shown in FIG.
The movable shield 3 is provided at the center of the contact base so as to freely advance and retreat, and the same elements as those in FIG.

That is, in the contact stand 1 having the same shape as the contact stand 13 shown in FIG. 4, the upper and lower sides of the disk formed on the outer periphery of the rear end of the cylindrical portion 1a are inserted from behind the connection conductor 11. It is fixed with a pair of bolts 12.

An annular convex portion 1c is formed at the center of the bottom of the cylindrical portion 1a of the contact base 1, and a through hole formed at the center portion has a shaft portion 3a of the movable shield 3 described below. The rear portion penetrates, and a large washer attached to the rear surface of the contact base 1 and a spring pin 16 press-fitted into the rear portion prevent the front portion from coming off.

At the front end of the movable shield 3, a head 3b having the same diameter as the disconnecting rod 10 is formed, and at the back of the head 3b, a projection 3c is formed. A return spring 5 is loosely fitted to the shaft portion 3a of the movable shield 3 in advance.
The front end is maintained in the vertical direction by the outer periphery of the convex portion 3c, and the rear end is maintained in the vertical direction by the convex portion 1c, and is slightly compressed in FIG.

The rear face of the outer periphery of the head 3b of the movable shield 3 is in contact with the opposing surface of the front end of each contact 4, the outer periphery of the front end of the head 3b is chamfered in an arc shape, and the front end face is the front end of the shield 2. It protrudes slightly from the surface.

The rear shield 17 attached to the back of the connecting conductor 11 is substantially hemispherical, and has a counterbore 17a formed from the rear to the left and right of the center, and a pan inserted into the counterbore from the rear. It is fixed to the connection conductor 11 via a small screw.

At the center of the rear shield 17, there is formed a through hole into which the rear portion of the shaft portion 3a is fitted by the retreat operation of the movable shield 3 described later. In addition, above and below the front,
A counterbore hole into which the head of the bolt 12 fits loosely is formed.

In the main circuit disconnecting device into which the movable shield 3 is inserted, the disconnecting rod 10 of the lightning arrester shown in FIG.
Is pushed rearward as shown by arrow A, and when this rear end is fitted to the opposing surface of each contact 4, the movable shield 3 is also pushed rearward as shown by arrow B, and the return spring 5 is compressed. The head 3b retreats as shown by a chain line, and the rear part of the shaft 3a retreats into a through hole of the rear shield 17.

When the disconnecting rod 10 is pulled out and the head 3b of the movable shield 3 is fitted to the opposing surface of each contact 4,
The front end face of the movable shield 3 projecting slightly forward from the front end face of the shield 2 alleviates the electric field strength of the space of the insulating gas around the front end of the main circuit disconnector including the inner periphery of the through hole at the front end of the shield 2. Is done.

Accordingly, the electric field strength of the insulating gas atmosphere near the front surface of the main circuit disconnector can be reduced without increasing the outer diameter and depth of the shield 2, so that the withstand voltage characteristics in front of the main circuit disconnector can be reduced. Can be prevented from dropping,
It is possible to prevent an increase in the outer shape of the gas insulated metal closed switchgear incorporating the main circuit disconnector, and to prevent an increase in installation floor area due to the increase in the outer shape.

In the above embodiment, the front surface of the head 3b of the movable shield 3 is a flat surface.
By using a curved surface 3R similar to the curved surface 2R on the outer periphery of the front end of the above, the electric field relaxation effect can be further enhanced.

Next, FIG. 2 is a view showing a second embodiment of the main circuit disconnector of the present invention, and FIG. 1 shown in the first embodiment.
FIG. 4 is a diagram corresponding to FIG. 2 differs from FIG. 1 shown in the first embodiment in that:
In the connection structure between the disconnecting rod 10 and the connection conductor 11, a contact plate 9 is inserted into the inner periphery of the front end of the contact base 8 instead of the contact 4 and the coil spring 6 shown in FIG.

That is, the contact table 8 has a curved surface 2 formed on the outer periphery of the front end of the shield 2 shown in FIG.
A curved surface 8R substantially the same as R is formed, and a concave portion 8a into which the movable shield 3 is loosely fitted is formed at the center. At the bottom of the concave portion 8a, a convex portion 8c is formed together with a through hole through which the shaft portion 3a of the movable shield 3B passes.

At the front end of the concave portion 8a, a shallow groove is formed in an annular shape, and the groove is formed from a strip-shaped beryllium copper plate, and arc-shaped protrusions are alternately formed on both surfaces by press working and silver-plated. The contact plate 9 is inserted, and the convex portion on the outer surface side of the contact plate 9 contacts the bottom surface of the groove formed in the contact base 8, and the convex portion formed on the inner peripheral side is the head of the movable shield 3B. Is in contact with the outer periphery of

In the main circuit disconnector in which the contact base 8 is configured as described above and the contact plate 9 and the movable shield 3 are inserted,
The disconnecting rod 10 of the lightning arrester is pushed backward as shown by arrow A,
When this rear end is fitted to the inner peripheral surface of the contact plate 9, the movable shield 3 is also pushed rearward as shown by the arrow B, and the return spring 5 is compressed, as shown by the broken line shown in the first embodiment. Evacuate to

When the disconnecting rod 10 is pulled out and the head 3b of the movable shield 3 is fitted on the inner peripheral surface of the contact plate 9, the movable shield 3 protrudes slightly forward from the front end surface of the contact base 8. The front end surface alleviates the electric field strength of the insulating gas around the front end of the main circuit disconnector including the inner periphery of the recess at the front end of the contact base 8.

Accordingly, the electric field strength of the insulating gas atmosphere near the front surface of the main circuit disconnector is reduced without increasing the outer diameter and depth of the contact base 8 as compared with the shield 2 shown in FIG. Can prevent a decrease in withstand voltage characteristics between the main circuit disconnector and the disconnecting rod in front of the main circuit disconnector, and increase the outer shape of the gas insulated metal closed switchgear incorporating the main circuit disconnector. Can be prevented, and the installation floor area can be prevented from increasing due to the increase in the outer shape.

In the above embodiment, the disconnecting rod 10
Has been described in the case of the disconnecting rod for connecting the lightning arrester and disconnecting for the test, but it is not limited to the disconnecting rod incorporated in the lightning arrester, for example, a disconnector that disconnects the main circuit, The same applies to the grounding disconnector incorporated in the disconnector as long as the disconnecting rod is inserted and removed in the axial direction to switch on and off the high-voltage main circuit.

[0044]

As described above, according to the present invention, the contact portion into which the tip of the disconnecting rod operated in the axial direction is inserted / removed is attached to the conductor fixed to the main circuit conductor, and the contact is made by the insertion operation of the disconnecting rod. The movable shield that retreats from the section and returns with the disconnection of the disconnecting rod and closes the opening of the concave is loosely fitted into the concave of the shield, and the electric field in the space at the opening end of the concave of the shield generated with the detachment of the disconnecting rod Since the increase in strength is eliminated by the movable shield closing the open end, a main circuit disconnector capable of maintaining the withstand voltage characteristics without increasing the insulation occupied space can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a main circuit disconnector of the present invention.

FIG. 2 is a sectional view showing a second embodiment of the main circuit disconnector of the present invention.

FIG. 3 is a right side view showing an example of a metal-closed switchgear in which a conventional main circuit disconnector is incorporated.

FIG. 4 is an enlarged detailed view of a portion C in FIG. 3;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Contact stand, 2 ... Shield, 3 ... Movable shield, 4 ...
Contact element, 5 ... Return spring, 6 ... Coil spring, 7 ... Space ring, 8 ... Contact table, 9 ... Contact plate, 10 ... Disconnect rod, 11 ... Connection conductor, 12 ... Hex bolt, 16 ... Spring pin, 17 ... Rear shield.

Claims (4)

[Claims] 1. A contact portion into which the tip of a disconnecting rod operated in the axial direction is inserted / removed, a recess formed in a rear portion of the contact portion, a conductor fixed to a main circuit conductor, and a loose fit in the recess. And a movable shield that retreats from the contact portion by the operation of inserting the disconnecting rod and returns by the disengaging operation of the disconnecting rod to close the opening of the concave portion. 2. The contact portion is a contact arranged annularly on the outer periphery of a contact base, and the shield comprises a shield tube having a U-shaped section provided on the outer periphery of the contact base and the contact. The main circuit disconnector according to claim 1, wherein: 3. The method according to claim 2, wherein the shield and the conductor are formed as a substantially hemispherical contact block having a U-shaped cross section, and the contact portion is a contact plate mounted in a concave portion having a U-shaped cross section of the contact table. The main circuit disconnector according to claim 1, characterized in that: 4. The main circuit disconnector according to claim 1, wherein a rear shield in which a rear portion of the movable shield is retracted is provided behind the main circuit conductor.