JPH08222093A - Vacuum circuit breaker and metal closed type switch gear - Google Patents

Abstract

PURPOSE: To provide a vacuum circuit breaker in which a drawing mechanism is simplified, and the setting area of a box body can be contracted. CONSTITUTION: A bushing 16 is protruded on the upper end of a frame body 14 for housing a vacuum bulb 15. A connecting conductor 18 is extended through the center part of the bushing 16. The lower end of the connecting conductor 18 is connected to the fixed side of the vacuum bulb 16. The shaft part 9a of a wheel 9A with shaft is extended through the upper end of the connecting conductor 18, and a wheel NB is inserted to the top end of the shaft part 9a. A shaft is extended through the shaft part 9a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum circuit breaker and a metal closed switchgear.

[0002]

2. Description of the Related Art FIG. 6 is a main circuit single wire connection diagram showing a conventional power receiving equipment of a spare 2CB system. In FIG.
A power receiving vacuum circuit breaker VCB1 is connected to a secondary side of a power receiving step-down transformer (not shown) via a cable head and an instrument current transformer CT1.

The load side of the power receiving vacuum circuit breaker VCB1 is connected to a common busbar via a current transformer CT2 for measuring instruments.
A busbar circuit breaker VCB3 is connected between the busbars, and a plurality of vacuum circuit breakers VCB2 for power supply are connected to the busbars, respectively. Further, a grounding transformer for instrument GPT is connected to each bus bar via a current limiting fuse.

The load side of each vacuum circuit breaker VCB2 is connected through a current transformer CT3 to a cable head attached to a power supply board (not shown) in which each vacuum circuit breaker VCB2 is housed, and is connected to each cable head. The zero-phase current transformer ZCT is connected to the cable.

Among these, in the main circuit on the power source side of the current transformer CT1 on the power source side, there is a surge protector LA and a transformer P for the instrument.
T1 is connected. A voltmeter V is connected to the secondary side of the voltage transformer PT1 via a changeover switch.

On the load side of the current transformer CT1 for each instrument, an overcurrent relay OC, an integrated watt hour meter WH, a power meter W,
The ammeter A is connected via the power factor meter PF and the changeover switch.

An overcurrent relay OC, an integrating wattmeter WH and a wattmeter A are connected to the load side of the current transformer CT3 connected to the load side of each vacuum circuit breaker VCB2. A ground fault direction relay DG is connected to the secondary side of the zero-phase current transformer ZCT.

Further, an undervoltage relay UV and an overvoltage relay OV are connected in parallel to the secondary side of the instrument grounding transformer GPT, and a ground voltage relay OVG and a ground phase indicator VO are further connected.

In the power receiving equipment connected in this way, when an accident occurs in the circuit connected to the regular power source and power cannot be fed, the vacuum circuit breaker VC1 on the regular side is opened and The spare vacuum circuit breaker VCB1 is turned on, and power is subsequently supplied to each load via each vacuum circuit breaker VCB2.

Next, FIG. 7 is a right side view showing an example of a metal closed type switchgear in which the power receiving vacuum circuit breaker VCB1 shown in FIG. 6 is housed. In FIG. 7, the inside of the box body 30 of the metal closed switchgear is divided into front and rear by a partition 30b. A power receiving vacuum circuit breaker VCB1 is housed on the front side of the partition 30b, and at the front end of the box body 10,
A door 30a is provided.

A small box body is provided on the upper front end of the box body 30.
34 is placed, a door 34a is attached to the front end of the box 34, and an auxiliary relay of a control circuit and the like are housed inside the box 34. An operation mechanism chamber 30d is formed below the power receiving vacuum circuit breaker VCB1.

An L-shaped partition 30 is provided at the rear of the partition 30b.
A bus bar 32 is provided so as to penetrate inside c in a direction orthogonal to the plane of the drawing. The upper electrode of the vacuum circuit breaker VCB1 for power reception is a partition 30b
It is connected to each bus bar 32 through a main circuit disconnecting portion that is provided through the.

An instrument current transformer 33 is attached to the lower surface of the partition 30c, and the lower pole of the power receiving vacuum circuit breaker VCB1 is raised from the rear lower end of the cable chamber 30e via the instrument current transformer 33. Connected to the upper end of the cable 34. The cable 34 is supported by the cable support 12, and at the bottom of the cable support 12, the zero-phase current transformer through which the cable 34 passes.
Thirteen is shown.

In the metal-closed type switch gear constructed as described above, the conductors that connect the main circuit disconnecting portion and the bus bar 32 are connected by overlapping the ends and tightening with a plurality of bolts. The same applies to the connection of the current transformer 33 for measuring instrument, the main circuit disconnecting section, and the conductor connecting the cable 34.

[0015]

However, in the metal-closed switchgear constructed as described above, as the number of power supply boards increases, the connecting portions of the conductors increase in proportion to the increase in the number of power feeding boards, and the tightening portions of the bolts increase. Will increase.

Since the busbar 32 is disposed on the upper portion of the box body 30, this bolt tightening work must be performed using a step or the like or by climbing on the upper portion of the box body 30. Further, the tightened portion of the bolt may be loosened during long-term operation of the power receiving equipment due to expansion and contraction of the busbar 32 due to repeated expansion and contraction of the busbar 32 due to increase / decrease in load or temporary stop. Therefore, at the time of maintenance / inspection, it is necessary to regularly inspect the fastening portion of the conductor and re-tighten the tightened portion of the bolt.

On the other hand, since the power receiving vacuum circuit breaker VCB1 and the power feeding vacuum circuit breaker VCB2 are drawer type in consideration of maintenance and inspection, the space occupied by the drawing mechanism and the maintenance and inspection are required. Because of the space, the width of the frontage becomes wider, and as a result, the width of the frontage of the box housing these vacuum circuit breakers becomes wider.

Then, in a large-sized power receiving equipment having a large number of loads to be fed, the installation area of this power receiving equipment is significantly widened in proportion to the number of power feeding boards, and the power receiving equipment of the building where the installation area is restricted. Cannot be adopted. Therefore, an object of the present invention is to provide a vacuum circuit breaker and a metal-closed switchgear that can reduce the installation area and the maintenance and inspection work.

[0019]

A vacuum circuit breaker according to a first aspect of the present invention has a bushing projecting from the upper end of an insulating frame in which a vacuum valve is housed, and the vacuum valve with respect to the axis of the bushing. It is characterized in that a conductor connected to the fixed side is penetrated, and a current-carrying wheel is attached to the shaft portion inserted into the upper end of this conductor.

In the vacuum circuit breaker according to the second aspect of the present invention, a bushing is provided so as to project from the upper end of an insulating frame in which the vacuum valve is housed, and a fixed side of the vacuum valve is fixed with respect to the axis of the bushing. The connected conductor was pierced through, the current-carrying ring was attached to the shaft inserted at the upper end of this conductor, the current transformer was stored in the lower part of the insulating frame, and the cable connection part was provided at the lower end of the insulating frame. Is characterized by.

Furthermore, in the metal-closed switchgear according to the third and fourth aspects of the present invention, the busbar is arranged on the upper part of the box body, and the current-carrying wheel is provided on the upper end of the conductor projecting on the upper part. It is characterized in that the vacuum circuit breaker is housed in a box and the vacuum circuit breaker is suspended on a bus bar through a conduction wheel. The busbar may have a C-shaped vertical cross section.

[0022]

In the vacuum circuit breaker and the metal-closed switchgear configured as described above, the vacuum circuit breaker housed in the box body can be freely inserted and removed through the current-carrying wheels rolling on the bus bar. The electric power supplied to the motor is supplied through the current-carrying wheels, and the contact resistance between the current-carrying wheels and the busbar is always constant due to the weight of the vacuum circuit breaker.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the vacuum circuit breaker and metal-closed switchgear of the present invention will be described below with reference to the drawings. FIG.
2 is a front view showing an embodiment of the vacuum circuit breaker and the metal closed switchgear of the present invention, and FIG. 2 is a plan view of FIG.

In FIG. 1, to the left and right of the central box 7,
Frame frames 7a and 7b having a narrow width are attached. On the upper ends of the box body 7 and the frame frames 7a and 7b, a busbar box 6 having a wide width and described later in detail is placed.

A cable support 12 is fixed to the left end of the lower portion of the box body 7. On the right side of the cable support 12, cable supports 12A which are slightly smaller than the cable support 12 are fixed at equal intervals. Zero-phase current transformers 13 are symmetrically attached to the lower sides of the cable supports 12A.

A high-pressure cross-linked polyethylene cable (hereinafter referred to as a cable) 4 raised from a pit (not shown) formed on the floor on which the box 7 is installed is loosely fitted in each of the zero-phase current transformers 13. However, it is supported by each cable support 12A.

The bus box 6 has a vertical section C, which will be described later with reference to FIG.
Shaped copper plate busbars 2 on the left and right in three pairs, as shown in Fig. 2, R
They are arranged in parallel for the phase, the S phase, and the T phase.
These busbars 2 are respectively fixed via insulators 5 fixed to the lower surface of the upper end of the busbar box 6.

FIG. 3 is a partially enlarged perspective view of the busbar 2 and the vacuum circuit breakers 1 and 1A shown in FIGS. 1 and 2 as seen obliquely from above. 4 is an enlarged detailed view of the vacuum circuit breakers 1 and 1A shown in FIGS. 1 and 2 as viewed from the right side.

Of these, in FIG. 3, the busbar 2 is formed by bending the longitudinal section into a C-shape, and two sets of C-shaped open sides face each other to form one set of one phase. A groove 22 having a U-shaped cross section is formed in advance in the center of the inner side surface of each bus bar 2.

On the other hand, the main circuit disconnecting portion 8 projecting from the upper ends of the vacuum circuit breakers 1 and 1A has the main circuit disconnecting portion 8 shown in FIGS.
As shown in FIG. 5, which shows an exploded perspective view of the above, a truncated cone-shaped bushing 16, a strip-shaped connecting conductor 18 whose lower portion is embedded in the center of the bushing 16, and a rotatable upper end of the connecting conductor 18 are freely rotatable. And wheels 9A and 9B which will be described later with reference to FIG.

That is, the upper end of the connecting conductor 18 has a semicircular shape, and a shaft hole 18a is formed at the center of the semicircular shape as shown in FIG. A shaft portion 9a of a wheel 9A made of a copper material and shown in FIG. 5 is inserted into the shaft hole 18a.

Through holes are formed in the shaft portion 9a with respect to the shaft center, and bearings 21 are press-fitted at both ends of the through holes. In this pair of bearings 21, a shaft 20 having a stepped portion at the left end formed with a screw is inserted from the right side as shown in FIG. A male screw 9b is formed on the outer periphery of the shaft portion 9a from the central portion to the left end.

The shaft portion 9a of the wheel 9A is inserted into a shaft hole 18a formed at the upper end of the connecting conductor 18. Further, as shown in FIG. 5, a wheel 9B having a female screw hole formed in the center thereof is screwed into the left end of the shaft portion 9a inserted into the shaft hole 18a.

The wheels 9A and 9B are the same as the wheels 9B.
The connecting conductor 18 is rotatably supported by a nut or washer (not shown) screwed to the left end of the shaft 20 protruding leftward from the female screw hole.

On the other hand, in each of the vacuum circuit breakers 1 and 1A, as shown in FIG. 4, three vacuum valves 15 are provided inside a frame body 14 having a truncated cone-shaped bushing 16 protruding from the upper end surface thereof. It is stored. The lower end of the connecting conductor 18 is connected to the upper end of the stationary side energization shaft of the vacuum valve 15.

A penetrating current transformer 3 for an instrument is housed at the lower end of the frame body 14, and a cable connecting portion 10 is fixed to the lower surface of the frame body 14, and the axis center of the cable connecting portion 10 is fixed. The cable 4 is connected to the central conductor (not shown). A conductor (not shown) connected to the movable side energizing shaft of the vacuum valve 15 penetrates the measuring instrument current transformer 3 and is connected to the cable connecting portion 10.

In the metal-closed switchgear configured as described above, when the vacuum circuit breaker 1 (1A) is connected to the busbar 2 via the main circuit disconnecting section 8 as shown by an arrow A in FIG. Wheels 9A and 9B rotatably attached to the upper end of the main circuit disconnecting section 8 provided at the upper end of the vacuum circuit breaker 1 (1A) via a connecting conductor 18 are inserted from the right end of the bus bar 2.

At this time, the lower end of the wheel 9A is placed on the lower end of the right busbar 2 of the set of busbars 2 shown in FIG. 3, and the lower end of the left wheel 9B is placed on the lower end of the left busbar 2. To do. Then, the right end of the shaft 20 penetrating the wheels 9A and 9B is loosely fitted into the groove 22 formed inside the bus bar 2 on the right side. Similarly, the left end of the shaft 20 is loosely fitted in the groove 22 formed inside the left busbar 2.

At this time, the diameters of the shaft 20 and the wheels 9A and 9B and the heights of the groove 22 and the conductor 22 to the inside of the lower ends of the lower end surfaces of both ends of the shaft 20 are lightly in contact with the lower surface of the groove 22. It is set.

Therefore, it is taken into consideration that the lower end of the conductor 2 is bent by the load of each vacuum circuit breaker 1, 1A, and the contact pressure between the wheels 9A, 9B and the lower end of the conductor 2 does not change. ing.

When each vacuum circuit breaker 1, 1A is inserted into a predetermined position, each cable 4, 11 raised from the lower part of the box body is connected to each vacuum circuit breaker 1, corresponding to the upper part of each cable.
Via each cable connection part 10 hung vertically at the lower end of 1A,
Connect to each vacuum circuit breaker 1, 1A.

In the metal-closed switchgear configured as described above, each wheel is pressed by contacting the connection portion between each vacuum circuit breaker 1, 1A and the bus bar 2 in accordance with the weight of each vacuum circuit breaker 1, 1A. Since the main circuit current is passed through the contact portion of the contact pressure between 9A and 9B and the bus bar 2, the contact pressure of the contact portion can always be kept constant.

Therefore, like the disconnecting section and the busbar connecting section adopted in the conventional metal-closed switchgear, bolts and the like generated by the heat cycle of energization / stoppage accompanying opening / closing of the vacuum circuit breaker are prevented. It is possible to prevent overheating and welding of the connection portion due to looseness.

In addition, when pulling out the vacuum circuit breakers for maintenance and inspection, the busbars 2 are converted into conventional metal-closed switch gears by sequentially pulling out from the vacuum circuit breaker 1A located at the right end to the right side. It can also be used as a drawer rail that has been adopted.

Therefore, not only the internal structure of the metal-closed switchgear is simplified and the assembly is facilitated, but also
Since the packaging density of the vacuum circuit breakers can be increased, the installation area of the metal closed switchgear can be reduced.

In the above embodiment, a plurality of leaf springs are continuously provided at the lower ends of the conductors 2, and a round bar-shaped conductor is placed on the upper side of the leaf springs, as shown in FIG. The variation in the contact pressure between the wheels 9A, 9B and the busbar due to a manufacturing error in the dimension between the groove 22 and the lower end of the busbar 2 may be reduced.

In this case, the wheels 9A and 9 shown in FIG.
A semi-circular groove may be formed on the outer circumference of B, and the wheels 9A and 9B may be suspended through the groove on a round rod-shaped conductor to add a function as a guide rod to the conductor.

Further, the round bar may be a square bar to increase the rigidity by increasing the longitudinal section coefficient and prevent the bending. In this case, U-shaped grooves may be formed on the outer circumferences of the wheels 9A and 9B so as to correspond to the square bars.

[0049]

As described above, according to the invention of claim 1,
A bushing projects from the upper end of the insulating frame that houses the vacuum valve inside, and a conductor connected to the fixed side of the vacuum valve penetrates the shaft center of this bushing, and the shaft part inserted at the upper end of this conductor By inserting the energization wheel into the box, the vacuum circuit breaker housed in the box can be inserted and removed via the energization wheel rolling on the busbar, and the power supplied to the vacuum circuit breaker is supplied through the energization wheel. Since the contact resistance between the current-carrying wheel and the bus bar is always made constant by the weight of the vacuum circuit breaker, it is possible to obtain a vacuum circuit breaker that can reduce the installation area and maintenance and inspection work.

According to the second aspect of the invention, a bushing is provided so as to project from the upper end of the insulating frame in which the vacuum valve is housed, and the bushing is connected to the fixed side of the vacuum valve with respect to the axis of the bushing. By passing through the conductor, inserting the current-carrying ring into the shaft part inserted at the upper end of this conductor, housing the current transformer under the insulating frame, and providing the cable connection part at the lower end of the insulating frame,
The vacuum circuit breaker housed in the box can be freely inserted and removed via the energizing wheel that rolls on the busbar, and the power supplied to the vacuum circuit breaker is supplied via the energizing wheel. Since the contact resistance is always kept constant by the weight of the vacuum circuit breaker, it is possible to obtain a vacuum circuit breaker which can reduce the installation area and maintenance and inspection work.

Further, according to the invention described in claims 3 and 4, there is provided a vacuum circuit breaker in which a bus bar is arranged on an upper portion of a box body and a conducting wheel is provided on an upper end of a conductor projecting on the upper portion. It is housed in a box and the vacuum circuit breaker is suspended on the bus bar via the energizing wheels, so that the vacuum circuit breaker housed in the box can be inserted and removed freely via the energizing wheels rolling on the bus bar, and the vacuum shut-off Since the electric power supplied to the device is supplied through the current-carrying wheels and the contact resistance between the current-carrying wheels and the bus bar is always constant due to the weight of the vacuum circuit breaker,
It is possible to obtain a metal-closed switchgear that can reduce the installation area and maintenance and inspection work.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a vacuum circuit breaker of the present invention and a metal-closed switchgear of the present invention in which the vacuum circuit breaker is housed.

FIG. 2 is a plan view of FIG.

FIG. 3 is a partially exploded enlarged perspective view of FIG.

FIG. 4 is an enlarged detailed front view showing an embodiment of the vacuum circuit breaker of the present invention.

5 is a partially enlarged exploded perspective view of FIG.

FIG. 6 is a main circuit single wire connection diagram showing an example of a power receiving facility in which a conventional metal closed switchgear is installed.

FIG. 7 is a right side view showing an example of a conventional metal closed switchgear.

[Explanation of symbols]

1, 1A ... vacuum circuit breaker, 2 ... bus bar, 3 ... current transformer, 4,11
... Cable, 5 ... Insulator, 6 ... Busbar box, 7 ... Box body, 8 ... Main circuit disconnector, 9A, 9B ... Wheels, 9a ... Shaft part, 10 ... Cable connection part, 12, 12A ... Cable support, 13 ... Zero-phase current transformer, 14 ... Frame, 15 ... Vacuum valve, 16 ... Bushing, 18 ...
Connection conductor, 20 ... Shaft, 21 ... Bearing.

Claims (4)

[Claims] 1. An insulating frame having a vacuum valve housed therein and a bushing projecting from the upper end thereof; a conductor penetrating the shaft center of the bushing and having a lower end connected to a fixed side of the vacuum valve; A vacuum circuit breaker equipped with a current-carrying wheel rotatably inserted into the shaft that extends through the upper end of the. 2. An insulating frame having a vacuum valve housed therein and a bushing projecting from the upper end, a conductor penetrating the shaft center of the bushing and having a lower end connected to the fixed side of the vacuum valve, and the conductor. A current-carrying ring rotatably inserted into a shaft portion penetrating at the upper end of the current transformer, a current transformer housed in the lower portion of the insulating frame, and a cable connecting portion vertically provided at the lower end of the insulating frame. Vacuum circuit breaker. 3. A vacuum circuit breaker having a conductor suspended from a bus bar horizontally provided on an upper portion of the box body via an energizing wheel, and a conductor connecting the energizing wheel and a stationary side energizing shaft of a vacuum valve protruding from an upper end of the vacuum circuit breaker. Metal closed switchgear equipped. 4. The busbar is formed of a pair of conductive materials whose opening sides are opposed to each other and which has a C-shaped vertical cross section.
Switchgear described in.