JPH1014030A - Gas insulated switchgear - Google Patents

Abstract

(57) [Problem] To provide a gas insulated switchgear having a plurality of power cables, and to shorten a stop period associated with repair, testing, and expansion of the power cables. SOLUTION: A plurality of cable heads 7a, 7b connected to a power cable 9a and housed in a gas insulating container 8a.
In a gas insulated switchgear including a cable unit having a cable unit connected to each of the cable heads 7a and 7b and housed in a gas insulated container, the gas insulated containers 8a and 8b of the cable head are separated from the gas insulated container of the bus. Each of the cable heads 7a, 7b and the bus were connected by separable conductors 27a, 27b, 28a, 28b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas insulated switchgear for connecting a plurality of power cables to one line.

[0002]

2. Description of the Related Art FIG. 9 shows, for example, I-Collaboration Research, Vol. 39, No. 6, pages 71 to 73, published on Feb. 3, 1984.
FIG. 25 is a partial cross-sectional side view of a cable unit having two power cables in the gas insulated switchgear having a multi-unit configuration shown in FIG. 25. In FIG. 9, reference numeral 1 denotes a gas insulated switchgear, 2 denotes a three-phase main bus, and one three-phase circuit is collectively gas-insulated and housed. Reference numerals 3a and 3b denote disconnectors housed in gas-insulated containers. The gas insulating container of the disconnector 3b is
It is hermetically connected to the gas insulating container 8a of the cable head 7a. 4 is a circuit breaker, 5a, 5b and 5c are earthing switches, 6a and 6b are current transformers, 7a and 7b are cable heads, 8a and 8b are gas-insulated containers of cable heads, 9
a and 9b are power cables, 10a and 10b are cable cones made of synthetic resin, 11a and 11b are shield conductors,
3a and 13b are hand holes, 14a and 14b are bottom flanges, 15a and 15b are shield rings, 16a and 16
b is a shield ring, 17a and 17b are connection conductors, 18
a, 18b are connection portions of the shield conductors 11a, 11b, 1
9a and 19b are connection portions of the cable cone, 20 is a connection conductor, and 21 and 22 are conductors.

[0003] The power cables 9a, 9b are connected by cable heads 7a, 7b to form a one-phase bus (conductor 21). In this example, three cables for one phase form a cable unit and are connected to the main bus 2. The cable unit, circuit breaker, transformer (not shown), and the like constitute a gas insulated switchgear.

Next, the operation will be described. In FIG. 9, the gas insulated switchgear 1 is a case in which two power cables are connected to one bus bar, but when the rated current of one power cable is, for example, 2000 A or less, 400
If it exceeds 0A, three or more power cables are required, and they are connected in the same shape to the left side of the cable head 7b in FIG. Since the plurality of power cables are connected in parallel, the plurality of power cables are opened and closed collectively by the circuit breaker 4 of the gas insulated switchgear 1. Circuits requiring a plurality of power cables as shown in FIG. 9 are large-capacity transformer circuits, large-capacity transmission lines, and the like.

[0005]

Since the conventional gas insulated switchgear is constructed as described above, it is used when replacing a poorly insulated power cable, during a withstand voltage test of the replaced power cable, when adding a power cable, and the like. , It was necessary to stop a plurality of power cables collectively for a long period of time.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and it is possible to replace a poorly insulated power cable, perform a withstand voltage test on the replaced power cable, and increase the number of power cables with a short stoppage. It is an object of the present invention to provide a gas-insulated switchgear.

[0007]

A gas insulated switchgear according to the present invention includes a plurality of cable heads connected to a power cable and stored in a gas insulated container, and a bus connected to each cable head and stored in the gas insulated container. In the gas insulated switchgear including the cable unit having the following, each gas insulated container of the cable head and the gas insulated container of the bus are connected via a detachable gas insulated branch container, and each cable head and the bus are separated. These are connected by possible conductors.

In addition, each gas insulating container of the cable head and the gas insulating container of the bus are connected to each other with a gas insulating branch container capable of being separated, and each cable head and the bus are connected via a disconnector. is there. In addition, the bellows is interposed between each gas-insulated container of the cable head and the gas-insulated branch container, and the two containers are connected to each other.

Further, the gas insulated container and the gas insulated branch container of the cable head are separated from each other so that they can be sealed. Further, a connection port for mounting a ground switch for emitting induced current is provided in the gas insulating container of the cable head.

Further, a current transformer for determining a cable ground fault is provided in a cable head and a power cable system connected to the cable head. Still further, the central axis of each gas insulating container of the cable head is disposed on a substantially vertical plane including the central axis of the bus gas insulating container.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view of a main part of one phase of a cable unit of the gas insulated switchgear, and FIG.
FIG. 2 is a sectional view taken along line II. FIG. 3 is a cross-sectional view of FIG. 2 from which a separating conductor is removed. FIG. 4 is a cross-sectional view in which a cable head portion is separated from FIG. 2 and a bushing for withstand voltage test is attached. 1, 2, 3 and 4, 1
Is a gas insulated switchgear, and 3b is a disconnector of the gas insulated switchgear 1 similar to that shown in FIG.

7a and 7b are cable heads, 8a and 8b
Is a gas insulating container of a cable head, 9a and 9b are power cables, 10a and 10b are cable cones made of synthetic resin, 11a and 11b are shield conductors, 13a and 13b are hand holes, 14a and 14b are bottom flanges, 17a and 17b.
17b is a connection conductor, 18a and 18b are shield conductors 11.
a and 11b, 19a and 19b are cable cone connections, 20 is a connection conductor, 24 is a gas insulated branch container,
25 is a hand hole, 26 is a shield conductor, 27a, 2
7b is a separation conductor, 28a and 28b are separation conductors,
29a and 29b are bellows, 30 is an insulating spacer, 31
a and 31b are gas-insulated containers 8a and 8b of the cable head.
, 32a and 32b are lids, and 33a and 33b are current transformers.

In FIG. 4, 34 is a bushing for withstand voltage test,
35 is an insulator, 36 is a terminal, 37 is a conductor, 38 is a flange for attaching a bushing, 39 is a cover, and 40 is a lid. In addition, SF6 gas is sealed in each gas insulating container. The configuration not shown before the disconnector 3b is shown in FIG.
Therefore, the description of FIG. 9 is cited. The power cables 9a, 9b are separated from the cable heads 7a, 7b, are connected to the bus via conductors 28a, 28b, 27a, 27b, and are connected to the disconnecting switch 3b to form one phase. In this example, three cables for one phase form a cable unit and are connected to the main bus. Cable unit and circuit breaker,
Transformers and the like are assembled to form a gas insulated switchgear.

In FIG. 1 to FIG.
The gas insulated branch container 24 is hermetically connected to the gas insulated container of the disconnector 3b, and the cable head 7 is connected to the gas insulated branch container 24 via bellows 29a and 29b, respectively.
The gas-insulated containers 8a and 8b a and 7b are hermetically connected. In FIG. 2, two cable heads are connected, but three or more cable heads can be similarly connected. 2
If one of the power cables 9b is stopped due to insulation failure or the like, the cable unit (for one line) cannot be used for a long time until the repair is completed. However, as shown in FIG. When the power cable 9b is cut off and the gas insulated branch container 24 is filled with SF6 gas again,
By using a, the cable unit (for one line) can be used as an emergency. In this case, it is necessary to reduce the load current of the cable unit.

To disconnect the cable head 7b of the power cable 9b, a disconnecting conductor 28 is used instead of the conductor 27b.
b may be removed. Since the above-described operation associated with disconnection of the power cable 9b can be performed in a short period of time, stopping the cable unit is short. As shown in FIG. 4, when one of the power cables 9a is in operation and the other power cable 9b is to be repaired, a withstand voltage test is performed after the repair or extension, or an extension work is performed, the bellows 29b is removed. A cover 39 is attached to the gas-insulated branch container 24, and a lid 40 is attached to the gas-insulated container 8b of the cable head 7b.

FIG. 4 shows that the bushing 34 is attached for the withstand voltage test, and the bushing conductor 37 is connected to the shield conductor 11.
b. Each container is filled with SF6 gas, and repair of the power cable 9b which takes a long time, withstand voltage test after repair or extension, and extension work can be performed while the power cable 9a is operated. The stop of the power cable 9a can be performed in a short time by a series of operations for removing and connecting the disconnecting conductor, and a time required for collecting and filling the gas. Although the insulating spacer 30 is provided in FIG. 2, the insulating spacer 30 may be omitted. In FIG. 4, a bushing 34 is used for withstand voltage test.
Although it is an example in which a power cable is attached, not shown in place of the bushing, a power cable can be connected and attached from the upper portion of the cable head, and the same can be implemented.

Embodiment 2 FIG. When the state shown in FIG. 4 is changed from the state shown in FIG.
Bellows 2 between gas-insulated containers 8a, 8b
Since the bellows 29a, 29b can be easily removed and attached by disposing the bellows 9a, 29b, repair of the power cables 9a, 9b, withstand voltage test after repair or extension, and extension work can be shortened. Can be implemented in time.

Embodiment 3 In FIG. 2, current transformers 33a and 33b are provided on the power cables 9a and 9b. If the power cables 9a and 9b have insulation failure, it is necessary to determine which of the power cables 9a and 9b is defective. However, usually, insulation resistance measurement is performed, and it takes much time to disconnect the circuit. It cannot be determined in a short time. The present invention seeks to achieve this economically in a short time. The magnitude and direction of each current are determined by the current transformers provided on the power cables 9a and 9b by the relays connected to the current transformers 33a and 33b, and which of the power cables 9a and 9b has a ground fault has occurred. Is determined. The criterion is that the electric current is large and the power cables 9a and 9b on the side where the electric current flows are defective.

Embodiment 4 FIG. 5 is a sectional view of a cable head part showing a main part of a fourth embodiment of the present invention.
, A cable head; 8b, a gas-insulated container of the cable head 7b; 9b, a power cable; 10b, a cable cone; 11b, a shielded conductor;
1b is a connection port of the gas insulating container 8b of the cable head 7b, 46b is a grounded switch for emitting induced current having an operation device 46c, 47b is a movable contact, and 48b is a fixed contact. As shown in FIG. 4, when a current is flowing through the cable head 7a, an induced voltage is induced in the shield conductor 11b and the like of the other cable head 7b, and when both ends are grounded, the induced current flows through the circuit. Induced. When the bushing 34 is attached to or detached from the cable head 7b as shown in FIG.
Grounding work is very troublesome to handle the induced current safely. For this reason, a sound power cable is also stopped at the time of operation, but as shown in FIG. 5, a grounding switch 46b for switching an induced current having an operation device 46c is connected to the connection port 31b of the gas insulating container 8b of the cable head 7b. When only the cable head 7a is attached, the operation can be performed safely even in the state where the current flows through the cable head 7a, and the operation can be performed in a short time.

Embodiment 5 FIG. 6 is a sectional view of a main part according to a fifth embodiment of the present invention. FIG. 6 is different from FIG. 1 (T-shaped arrangement) in that the center of the gas insulated containers 8a and 8b of the cable head 7a and the cable head 7b is provided on a vertical plane including the central axis of the gas insulated container of the disconnector 3b of the gas insulated switchgear. A shaft is provided. In FIG. 6, 41
Is a gas insulated branch container, 42 is a hand hole, 43 is a shield conductor, and 44 and 45 are separation conductors. 6, the same reference numerals as those shown in FIGS. 1 to 4 denote the same parts, and a description thereof will be omitted. In the case of FIG. 6 as well, as in FIG.
Can be opened and removed, and one cable head can be operated, and the other cable head can be repaired or the like.

In the case of FIG. 6, unlike the case of FIGS. 1 to 4, it does not spread in the interphase direction of the gas insulated switchgear, so even if two cable heads are provided, it is necessary to increase the interphase size of the gas insulated switchgear. In addition, the size of the gas-insulated switchgear can be reduced. Although FIG. 6 shows an example in which two power cables are used, three or more power cables can be arranged without increasing the inter-phase dimension. When a withstand voltage test is performed in FIG. 6, either the bushing method or the power cable connection method can be applied to the cable head 7a, but the power cable connection method is applied to the cable head 7b.

Embodiment 6 FIG. FIG. 7 is a sectional view of a main part according to the sixth embodiment of the present invention. Unlike FIGS. 1 to 4, a disconnector is provided instead of removing the disconnecting conductor. In FIG. 7, 49 is a gas insulated branch container, 50a and 50
Reference numeral b denotes a disconnector, for example, the one shown in Japanese Patent Publication No. 64-4291 can be used. 51a and 51b are movable contacts of the disconnector, 52a and 52b are fixed contacts of the disconnector, 53a and 53b are shield conductors, 54 is a shield conductor, 55a and 55b are contacts, 56a and 56b
Is an insulating operating rod, 57a and 57b are shaft seals, and 58a and 58b are operating devices for disconnecting switches. 1 to 4 in FIG.
Since the same reference numerals as those shown by the reference numerals indicate the same parts, the description thereof will be omitted.

In FIG. 7, when the power cable 9b breaks down, the movable contact 51 of the disconnector 50b is detected after detecting a faulty circuit.
b, the cable head 7b can be disconnected in a short time, and a sound power cable 9a
Can be put into operation in a short time. Since the two disconnectors are disposed inside the gas-insulated branch container 49, the disconnector portion can be reduced in size. FIG. 7 shows an example in which two disconnectors are provided inside the gas insulated branch container 49. However, when three or more power cables are connected, three or more disconnectors are similarly provided. I do. Also in FIG. 6, a disconnecting switch may be provided instead of the disconnecting conductor.

Embodiment 7 FIG. FIG. 8 is a plan view of a main part according to a seventh embodiment of the present invention. FIG. 8 shows the arrangement of the gas insulated container and the gas insulated branch container of the cable head when three or more power cables are connected. 8, 7a, 7b, 7c, 7d and 7e are cable heads, 8a, 8b, 8c, 8d and 8e are gas-insulated containers of a cable head, 59 is a gas-insulated branch container, 60 is a handhole, and 61 is a gas-insulated branch. Container, 62 is a handhole, 29a, 29b, 63a, 63b, 63c, 63d
Is bellows. In FIG. 8, the cable heads 7b and 7d are used to reduce the interphase size of the gas insulated switchgear.
May be omitted. In addition, the mounting angle θ = 90 ° between the gas insulating containers 8c, 8e, and 8d of each cable head with respect to the gas insulating branch container 61 is reduced to a smaller mounting angle, for example, 6 °.
It may be 0 °.

[0025]

Since the present invention is configured as described above, it has the following effects. According to the gas insulated switchgear according to the present invention, a cable unit having a plurality of cable heads connected to a power cable and housed in a gas insulated container, and a bus connected to each cable head and housed in the gas insulated container is provided. In the gas-insulated switchgear including, each gas-insulated container of the cable head and the gas-insulated container of the bus are connected via a separable gas-insulated branch container, and each cable head and the bus are connected by a separable conductor. Therefore, the faulty power cable can be disconnected and another healthy power cable can be used, and the suspension period for repair, testing, and expansion of the circuit can be shortened.

Also, since each gas-insulated container of the cable head and the gas-insulated container of the bus are connected via a gas-insulated branch container that can be separated, and each cable head and the bus are connected via a disconnector, respectively. The faulty power cable can be easily separated by the disconnector, and another healthy power cable can be used, so that the suspension period for repairing, testing, and expanding the circuit can be shortened.
In addition, since the above-mentioned containers are connected by interposing a bellows between each gas-insulated container of the cable head and the gas-insulated branch container, connection and disconnection of both containers are easy, and repair of the power cable can be performed in a short time. Can be implemented.

Further, since the gas insulated container and the gas insulated branch container of the cable head are separated from each other and can be sealed, a sound power cable can be used in a state where both containers are separated from each other. The test can be performed in a gas-insulated state. Further, since the connection port for mounting the induced current emission grounding switch is provided in the gas insulating container of the cable head, the installation of the induced current emission grounding switch is easy, and a safe operation can be easily performed in a short time.

Further, since the cable head and the power cable system connected to the cable head are provided with the cable ground fault determining current transformer, a faulty power cable can be immediately determined. Furthermore, since the central axis of each gas insulating container of the cable head is disposed on a substantially vertical surface including the central axis of the gas insulating container of the bus bar, the inter-phase dimension can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view of a main part of a gas insulated switchgear showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a cross-sectional view of FIG. 2 from which a separating conductor is removed.

FIG. 4 is a cross-sectional view in which a cable head portion is separated from FIG. 2 and a bushing for withstand voltage test is attached.

FIG. 5 is a sectional view of a cable head part showing a main part of a fourth embodiment of the present invention.

FIG. 6 is a sectional view of a main part according to a fifth embodiment of the present invention.

FIG. 7 is a sectional view of a main part according to a sixth embodiment of the present invention.

FIG. 8 is a sectional view of a main part according to a seventh embodiment of the present invention.

FIG. 9 is a partial cross-sectional side view showing a conventional gas insulated switchgear.

[Explanation of symbols]

7a, 7b Cable head 31a, 31b Connection port 8a, 8b Gas insulated container of cable head 9a, 9b Power cable 24 Gas insulated branch container 27a, 27b Separating conductor 28a, 28b
Separating conductor 29a, 29b Bellows 30
Insulating spacers 33a, 33b Current transformer 34 Bushing for withstand voltage test 39 Cover 40 Lid 31b Connection port for gas-insulated container 46b Grounding switch for induced current emission 41 Gas-insulated branch containers 44, 45 Disconnect conductor 49 Gas-insulated branch container 50a, 50b Disconnector 56a, 56b Insulated operating rod 58a, 58b Disconnector operating device 7a, 7b, 7c, 7d, 7e Cable head 8a, 8b, 8c, 8d, 8e Gas insulated container for cable head 59, 61 Gas insulated branch container 29a, 29b, 63a, 63b, 63c, 63d Bellows

Claims (7)

[Claims] 1. A gas insulated switchgear including a cable unit having a plurality of cable heads connected to a power cable and housed in a gas insulated container, and a bus connected to each of the cable heads and housed in the gas insulated container. ,
A gas insulated switchgear in which each gas insulated container of the cable head and the gas insulated container of the bus are connected with a detachable gas insulated branch container interposed therebetween, and each of the cable heads and the bus are connected by a detachable conductor. apparatus. 2. A gas insulated switchgear including a cable unit having a plurality of cable heads connected to a power cable and housed in a gas insulated container, and a bus connected to each of the cable heads and housed in the gas insulated container. ,
A gas insulated switchgear in which each gas insulated container of the cable head and the gas insulated container of the bus are connected via a detachable gas insulated branch container, and each of the cable heads and the bus are connected via disconnectors. apparatus. 3. The gas insulated switchgear according to claim 1, wherein the bellows are interposed between each gas insulated container of the cable head and the gas insulated branch container so as to connect the two containers. 4. The gas-insulated switchgear according to claim 1, wherein the gas-insulated container and the gas-insulated branch container of the cable head are separated from each other so that they can be sealed. 5. The gas-insulated switchgear according to claim 1, wherein a connection port for mounting a grounded switch for emitting induced current is provided in the gas-insulated container of the cable head. 6. The gas insulated switchgear according to claim 1, wherein a current transformer for determining a cable ground fault is provided in the cable head and the power cable system connected thereto. 7. The gas according to claim 1, wherein a central axis of each gas insulating container of the cable head is disposed on a substantially vertical plane including a central axis of the bus gas insulating container. Insulated switchgear.