WO2000069041A1

WO2000069041A1 - Vacuum switch gear

Info

Publication number: WO2000069041A1
Application number: PCT/JP1999/002380
Authority: WO
Inventors: Minoru Kobayashi; Toshimasa Maruyama; Toshifumi Sato; Seiichi Miyamoto; Takayuki Itotani; Tomotaka Yano
Original assignee: Mitsubishi Denki Kabushiki Kaisha
Priority date: 1999-05-07
Filing date: 1999-05-07
Publication date: 2000-11-16
Also published as: AU3629199A; TW492029B

Abstract

A vacuum switch comprises a vacuum container that houses a main circuit breaker and a grounding switch. An isolating switch for electrically connecting and disconnecting between the main circuit switch and a bus conductor or a load conductor is housed in another container filled with insulating liquid or gas. The container filled with insulator is provided with a window through which the contacts of the isolating switch can be observed.

Description

Description Vacuum insulated switchgear Technical field

The present invention relates to a vacuum insulated switchgear for receiving and distributing electric power. Background art

FIG. 9 is a configuration diagram showing a conventional gas-insulated switch gear disclosed in, for example, Japanese Patent Publication No. 7-284488, and FIG. 10 is a circuit diagram showing a circuit of the gas-insulated switch gear of FIG. In the figure, the busbar side pushing 2a and the power transmission cable side bushings 2b and 2c penetrate the wall of the container 1, respectively. The load-side conductor 2 is supported on each of the transmission cable side pushings 2 b and 2 c. An insulating gas is sealed in the container 1 and the first to third switches 3, 4, 5 and the vacuum arc extinction chamber 9 are accommodated therein.

As shown in FIG. 9, the three-phase bus-side branch conductors 6 are supported by insulating support insulators 11 and arranged in the container 1. As shown in FIG. 10, the three-phase bus-side branch conductor 6 is connected to an external three-phase bus (not shown) via a bus-side pushing 2a for each phase. I have.

The bus-side branch conductor 6 is connected to the intermediate conductor 60 via a switchgear in the vacuum arc extinction chamber 9 and the first switch 3, and is branched in two directions by the intermediate conductor 60. The intermediate conductor 60 is fixedly supported by the insulating support insulator 60a. The intermediate conductor 60 is connected to the load-side conductor 2 of the power transmission cable-side pushing 2b, 2c via the second and third switches 4, 5, respectively. The load-side conductor 2 is connected to an external power transmission cable (not shown).

Each of the first to third switches 3, 4, 5 has a metal link 8, an insulating link 7, and a swing electrode. The oscillating electrode is oscillated about the pivot axis by the driving force of a driving source (not shown) being transmitted through the metal link 8 and the insulating link 7. The first switch 3 opens and closes the inside of the vacuum arc-extinguishing chamber 9 according to the swing position of the swing electrode. A closed position for connecting the output electrode of the device to the fixed electrode protruding from the corresponding position of the intermediate conductor 60, and a connection position for connecting the oscillating electrode to the grounding conductor 10a. Thus, a disconnection position away from the fixed electrode and the grounding conductor 10a is realized.

In addition, the second and third switches 4 and 5 are fixed to the load-side conductor 2 and the intermediate conductor 60 at positions corresponding to the load-side conductor 2 and the intermediate conductor 60, respectively, by the swing of the swing electrodes. The configuration is such that the same three positions as those of the first switch 3 are realized between the bodies 10 b and 10 c.

In the conventional gas insulated switch gear as described above, a main circuit switch for connecting and disconnecting the bus-side branch conductor 6 and the load-side conductor 2 and a grounding switch for grounding the load-side conductor 2 include: The bus-side branch conductor 6 is connected to the bus outside the container 1 via the bus-side bushing 2a, and the load-side conductor 2 is connected to the power transmission cable-side pushing 2b, 2 together with the grounding conductor. Since it is connected to the power transmission cable outside the container 1 via c, a miniaturized gas-insulated switch gear can be provided.

However, in the conventional gas insulated switch gear described above, the first to third switches 3, 4, and 5 have a container for each of the three phases, the ground, and the poles at the disconnection position. Since it is necessary to secure an insulation distance corresponding to the insulating gas (here, SF ₆ gas) sealed in 1, the size of each of the first to third switches 3, 4, and 5 becomes larger. I will. In addition, since it is necessary to maintain a sufficient distance between the switches 3, 4, and 5, the efficiency of use of the space in the container 1 is low, and miniaturization of the container 1 is limited. In addition, it is also possible to arrange devices such as switches 3, 4, and 5 in a vacuum vessel. In that case, when the vacuum vessel is evacuated, it is heated with the equipment installed in the vessel. Therefore, it is necessary to use components that can withstand the thermal stress (800 ° C or more) at that time, which does not lead to simplification and downsizing of components.

Further, since the vacuum arc extinguishing chamber 9 is provided for each single phase in the three-phase circuit shown in FIG. 10, miniaturization of the container 1 is restricted in order to secure these arrangement positions, and the product cost is reduced. There was a problem that led to a rise.

Furthermore, since the contact position of the disconnector is in the container 1 and cannot be seen from the outside, the contact position was indirectly grasped by an open / close indicator or the like via a link. Disclosure of the invention

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and the safety and reliability are improved by separating a disconnector outside a vacuum vessel and using another insulating medium. An object is to obtain a vacuum insulated switchgear that can be improved.

A vacuum-insulated switch gear according to the present invention includes a bus-side conductor connected to a bus, a load-side conductor connected to a load-side device, a vacuum container having an inside kept in a vacuum, a bus-side conductor provided in the vacuum container. Main circuit switch that electrically connects and disconnects the load side conductor from the load side conductor.Earth ground switch that is installed in the vacuum vessel and electrically connects and disconnects the load side conductor and the grounding conductor. An insulating medium container provided outside the vacuum container and containing the insulating medium; and an insulating medium container provided in the insulating medium container and electrically connecting any of the bus-side conductor and the load-side conductor to the main circuit switch. It has a disconnector to connect and disconnect. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a front view showing the internal structure of a vacuum insulated switchgear according to Embodiment 1 of the present invention,

FIG. 2 is a side view showing the vacuum insulated switch gear of FIG. 1,

FIG. 3 is a circuit diagram showing a circuit for one phase of the vacuum insulated switch gear of FIG. 1,

FIG. 4 is a front view showing the internal structure of a vacuum insulated switchgear according to Embodiment 2 of the present invention in a see-through manner.

FIG. 5 is a side view showing the vacuum insulated switch gear of FIG. 4,

FIG. 6 is a circuit diagram showing a circuit for one phase of the vacuum insulated switch gear of FIG. 4,

FIG. 7 is an explanatory diagram showing changes in the operating state of the main circuit switch and the earthing switch by the drive mechanism of FIG. 4,

FIG. 8 is a front view showing the internal structure of a vacuum insulated switchgear according to Embodiment 3 of the present invention in a see-through manner.

FIG. 9 is a configuration diagram showing an example of a conventional gas-insulated switch gear. FIG. 10 is a circuit diagram showing a circuit of the gas-insulated switch gear of FIG. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

Embodiment 1-FIG. 1 is a front view showing the internal structure of a vacuum insulated switchgear according to Embodiment 1 of the present invention, FIG. 2 is a side view showing the vacuum insulated switchgear of FIG. 1, and FIG. FIG. 2 is a circuit diagram showing a circuit for one phase of a vacuum insulating switch gear.

In the figure, the interior of the three-phase vacuum vessel 20 is maintained at a high vacuum. In these vacuum vessels 20, a three-phase main circuit switch 21, a three-phase ground switch 23, and a plurality of bus-side conductors 24 are accommodated for each phase. The bus-bar-side conductor 24 is electrically connected to a bus (not shown).

The drive mechanism 22 of the main circuit switch 21 and the drive mechanism 25 of the ground switch 23 are arranged outside the vacuum vessel 20. A disconnector 31 and a load-side conductor 37 are accommodated in an insulating medium container 30 containing an insulating medium (liquid or gas). Further, the insulating medium container 30 is provided with a cable pushing 38 and a cable withstand voltage terminal 33 for connection to an external power transmission cable 34 as a load-side device. The load-side conductor 37 is connected to the cable pushing 38 in the insulating medium container 30. Further, the load-side conductor 37 is connected to the side connected to the main circuit switch 21 in the vacuum vessel 20 via the disconnector 31 and to the ground switch 23 in the vacuum vessel 20. Branched to the side and.

Further, the insulating medium container 30 is provided with a window 32 for visually checking the operation of the contact of the disconnector 31 from outside. In the insulating medium container 30, not only the disconnector 31 but also sensors such as a current transformer 35 and a transformer 36 and a cable withstand voltage terminal 33 are arranged. The cable withstand voltage terminal 33 is a terminal for applying a voltage to the power transmission cable 34 when the power transmission cable 34 is inspected.

In the above-described vacuum insulated switch gear, a current flows between the bus-side conductor 24 and the load-side conductor 37 by the pair of contacts of each main circuit switch 21 being connected and separated by the drive mechanism 22. And is shut off. Also, a pair of contacts of each ground switch 23 is driven The load-side conductor 37 is grounded or released from ground by being separated by the mechanism 25 o

The main circuit switch 21 and the ground switch 23 are each a drive mechanism 22 and a drive mechanism

By means of 25, the A, B, and C phases in Fig. 2 are opened and closed vertically as a unit. As a result, the influence of arcs between the phases is reduced, the insulation distance required in a vacuum may be secured, the arrangement efficiency can be improved, and the container and the configuration can be downsized.

The disconnector 31 in the insulating medium container 30 is used for disconnecting an electric device from a circuit in order to change a connection when no load is applied or to check the electric device. The disconnect switch 31 is operated by a drive mechanism (not shown) when the main circuit switch 21 is open. Since the disconnector 31 is not opened or closed during the passage of current, it is only necessary to withstand high voltage. For this reason, a sufficient insulation distance can be ensured by an insulating medium such as oil, pure water or an insulating gel-like liquid, or nitrogen gas, dry air or an insulating mixed gas thereof.

Therefore, the insulating medium container 30 is not subjected to thermal stress (800 ° C. or more) unlike the case of manufacturing a vacuum container. When a special insulating gas such as SF ₆ gas is used as the insulating medium, it is necessary to evacuate the inside of the container, so it is necessary to use a container that can withstand such pressure. In the first embodiment, since pure water and dry air can be used as described above, the container structure can be simplified without requiring strong rigidity unlike the SF ₆ gas container.

As described above, in the vacuum insulated switchgear of the first embodiment, the main circuit switch 21 and the ground switch 23 together with the bus-side conductor 24 are placed inside the vacuum vessel 20 integrated for each phase. Since they are housed and placed in a vacuum with excellent insulation properties, the insulation distance between them can be reduced, and the effects of arcs between phases can be prevented. Also, since the structure is simplified by the insulating medium container 30, the disconnector 31 and the current transformer

It is easy to install sensors such as 35 and the transformer 36 and the cable withstand voltage terminal 33, and a window 32 for visually confirming the operation of the contact of the disconnector 31 can be provided. Therefore, a vacuum insulating switch gear with high safety and reliability can be obtained. Embodiment 2

Next, FIG. 4 is a front view showing the internal structure of the vacuum insulated switch gear according to Embodiment 2 of the present invention, FIG. 5 is a side view showing the vacuum insulated switch gear of FIG. 4, and FIG. FIG. 3 is a circuit diagram showing a circuit for one phase of a switch gear.

In this example, the disconnector 31 is disposed not between the load-side conductor 37 and the main circuit switch 21 but between the main circuit switch 21 and the bus-side conductor 24. The disconnector 31 and the bus-side conductor 24 are collectively housed in an insulating medium container 40 containing an insulating medium (liquid or gas). The insulating medium container 40 is provided with a window 32.

A drive mechanism 26 that operates in three stages is arranged outside the vacuum vessel 20. Other configurations are the same as those of the first embodiment.

In such a vacuum insulated switch gear, as in Embodiment 1, the main circuit switch 21 and the ground switch 23 are housed in a vacuum having excellent insulation characteristics. The effect can be reduced, and the effects of arcs between phases can be prevented. Further, since the structure of the insulating medium container 40 can be simplified, the disconnector 31 can be freely arranged, and the structure for accommodating the bus-side conductor 24 can be relatively easily accommodated. In addition, when the drive mechanism 26 operates in three stages, the main circuit switch 21 and the grounding switch 23 are in a state where the contacts of the main circuit switch 21 are closed as shown in FIG. The state changes to a state in which both the contacts of the main circuit switch 21 and the ground switch 23 are open, and a state in which the contacts of the ground switch 23 are closed.

Accordingly, the operation of connecting and disconnecting the contacts of the main circuit switch 21 and the operation of connecting and disconnecting the contacts of the ground switch 23 can be performed by one drive source. That is, since the insulating medium container 31 can be easily configured, it is possible to design with a high degree of freedom, such as the arrangement of the disconnector 31, the installation position of the conductor, or the structure according to the mechanism configuration. Embodiment 3.

Next, FIG. 8 is a front view showing a vacuum insulated switch gear according to Embodiment 3 of the present invention. In this example, an insulating medium container 5 containing an insulating medium (liquid or gas)

The disconnector 31 is accommodated in the zero. The contacts of the disconnector 31 are driven It is moved up and down by the mechanism 51 in the same way as other contacts, and is opened and closed. At this time, the bus-side conductor 52 is flexibly connected in the insulating medium container 50. Other configurations are the same as those of the second embodiment.

In such a vacuum insulated switchgear, the contact of the disconnector 31 is moved up and down like other contacts, so that the mechanism can be shared and the stability of the mechanism can be achieved by unifying the axial direction of the mechanism. it can. In addition, the arrangement of the equipment is easy due to the restriction of the space and the mechanical part, and it is possible to prevent excessive conductor winding and unnecessary addition of a link mechanism.

Claims

The scope of the claims

1. Bus-side conductor connected to the bus,

A load-side conductor connected to the load-side device,

A vacuum vessel whose inside is kept in a vacuum,

A main circuit switch that is provided in the vacuum vessel and electrically connects and disconnects the bus-side conductor and the load-side conductor;

A grounding switch provided in the vacuum vessel for electrically connecting and disconnecting between the load-side conductor and the grounding conductor;

An insulating medium container provided outside the vacuum container and containing an insulating medium; and an electric medium provided in the insulating medium container and electrically connected to one of the bus-side conductor and the load-side conductor and the main circuit switch. Disconnector that connects and disconnects

A vacuum insulated switch gear.

2. The main circuit switch and the grounding switch are each composed of three phases, each phase is housed in a separate vacuum vessel, and the disconnector is composed of three phases. 2. The vacuum insulating switch gear according to claim 1, wherein the vacuum insulating switch gear is housed in a separate insulating medium container for each phase.

3. The vacuum insulated switchgear according to claim 1, wherein the disconnector is disposed between the load-side conductor and the main circuit switch, and the bus-side conductor is housed in the vacuum vessel. .

4. The vacuum insulation according to claim 1, wherein the disconnector is disposed between the main circuit switch and the busbar-side conductor, and the busbar-side conductor is housed in the insulating medium container. Switch gear.

5. The vacuum insulated switchgear according to claim 1, further comprising a current transformer, a transformer, and a cable pressure-resistant terminal respectively housed in the insulating medium container.

6. The vacuum insulating switch gear according to claim 1, wherein the insulating medium container is provided with a window for visually confirming the operation of the contact of the disconnector from outside.