U.S. patent application number 09/948759 was filed with the patent office on 2002-09-05 for switchgear.
Invention is credited to Kashima, Junichi, Mizuno, Satoshi, Mutoh, Yasubumi.
Application Number | 20020122288 09/948759 |
Document ID | / |
Family ID | 18773577 |
Filed Date | 2002-09-05 |
United States Patent
Application |
20020122288 |
Kind Code |
A1 |
Kashima, Junichi ; et
al. |
September 5, 2002 |
SWITCHGEAR
Abstract
The instrumentation transformers 6a to 6d and 7a to 7f for
measuring the voltage of the main circuit are arranged within the
container 15b located in the midst of the containers 15a to 15c. In
the present invention, the containers 15a and 15b are linked by the
insulating tube 21a and the primary-side lead lines 49 and 53
connected electrically to the primary-side terminal of the
instrumentation transformers 6a and 7a are made routed from the
container 15b through the insulating tube 21a to the container 15a,
and the containers 15b and 15c are linked by the insulating tube
21b and the primary-side lead lines 51 and 55 connected
electrically to the primary-side terminal of the instrumentation
transformers 6d and 7e are made routed from the container 15b
through the insulating tube 21b to the container 15c.
Inventors: |
Kashima, Junichi; (Hitachi,
JP) ; Mizuno, Satoshi; (Hitachi, JP) ; Mutoh,
Yasubumi; (Hitachi, JP) |
Correspondence
Address: |
DICKSTEIN SHAPIRO MORIN & OSHINSKY LLP
2101 L STREET NW
WASHINGTON
DC
20037-1526
US
|
Family ID: |
18773577 |
Appl. No.: |
09/948759 |
Filed: |
September 10, 2001 |
Current U.S.
Class: |
361/605 |
Current CPC
Class: |
H02B 5/06 20130101 |
Class at
Publication: |
361/605 |
International
Class: |
H02B 005/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 20, 2000 |
JP |
2000-290336 |
Claims
What is claimed is:
1. A switchgear installed in a main circuit from a power generator
to a transformer and structured in a phase-separation
configuration, comprising three containers arranged together; a
disconnecting switch having a breaker part disconnecting said main
circuit electrically and insulated by an insulating gas, said
breaker part arranged in each of said three containers, and a
manipulator for making contact to and leaving from a contact maker
of said breaker part; and plural instrumentation transformers for
measuring a voltage of said main circuit, wherein said plural
instrumentation transformers are installed in a container located
in a midst among said three containers.
2. A switchgear installed in a main circuit from a power generator
to a transformer and structured in a phase-separation
configuration, comprising three containers arranged together; a
disconnecting switch having a breaker part disconnecting said main
circuit electrically and insulated by an insulating gas, said
breaker part arranged in each of said three containers, and a
manipulator for making contact to and leaving from a contact maker
of said breaker part; and plural instrumentation transformers for
measuring a voltage of said main circuit, wherein a couple of
coadjacent containers among said three containers are linked by an
insulating tube; said plural instrumentation transformers are
installed inside a container located in amidst among said three
containers; a primary-side lead line for an instrumentation
transformer corresponding to a phase for an container located in
either of both ends among said three containers is routed from a
container located in a midst among said three containers through
said insulating tube into a corresponding container located in
either of both ends.
3. A switchgear installed in a main circuit from a power generator
to a transformer and structured in a phase-separation
configuration, comprising three containers arranged together; a
disconnecting switch having a breaker part disconnecting said main
circuit electrically and insulated by an insulating gas, said
breaker part arranged in each of said three containers, and a
manipulator for making contact to and leaving from a contact maker
of said breaker part; plural instrumentation transformers for
measuring a voltage of said main circuit, a switching part of a
disconnecting switch and an earthing switch connected electrically
to said main circuit and arranged in each of said three containers;
and an arrester; wherein a couple of coadjacent containers among
said three containers are linked by an insulating tube; said plural
instrumentation transformers are installed inside a container
located in amidst among said three containers; a primary-side lead
line for an instrumentation transformer corresponding to a phase
for an container located in either of both ends among said three
containers is routed from a container located in a midst among said
three containers through said insulating tube into a corresponding
container located in either of both ends.
4. A switchgear claimed in either of claims 1 to 3, wherein a
primary-side of said plural instrumentation transformers is
configured with an open-delta connection method or a start
connection method.
5. A switchgear claimed in either of claims 1 to 3, wherein the
height of a container located in a midst among said three
containers is higher than that of two other containers.
6. A switchgear claimed in either of claims 1 to 3, wherein said
plural instrumentation transformers are supported so as to be
suspended from a ceiling board installed above said container.
7. A switchgear claimed in claim 3, wherein said arrester is
supported so as to be suspended from a ceiling board installed
above said container.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a substation component for
the power generator installed in the power plants such as thermal
electric power plants, nuclear power plants and hydro-electric
power plants, especially to a switchgear installed on the main
circuit from the generators to the transformers.
[0002] As for the switchgear installed on the main circuit from the
generators to the transformers, for example, what is well known is
disclosed in Japanese Patent Laid-Open Number 61-1218 (1986). The
switchgear disclosed in this document is composed so that the
components for the individual phases are separated and the
switchgears are contained in the individual exterior covering,
respectively. The upper-side of the exterior covering containing
the switchgear is connected through the exterior covering
containing the connecting bus tie to the exterior covering
containing the disconnecting switch in step-wise configuration.
[0003] In this kind of conventional switch gear, the contact makers
of the breaker part of the disconnecting switch are made contact to
and leave from each other in responsive to the voltage value in the
main circuit. In order to measure the voltage value in the main
circuit, plural instrumentation transformers are installed at the
switchgears. Those instrumentation transformers are installed in
separate containers other than the containers containing the
breaker part of the disconnecting switch.
[0004] In recent years, many efforts are made for integrating
components into a unified and composite unit in order to downsize
the switchgears and reduce their cost. Along with this trend, there
arises strong request to accommodate plural instrumentation
transformers in the container including the breaker part of the
disconnecting switches. However, there are still unsolved problems
regarding the method for the layout of plural instrumentation
transformers in three containers arranged together.
SUMMARY OF THE INVENTION
[0005] A major object of the present invention is to provide a
switchgear enabling to increase the working efficiency for the
installation operation of the instrumentation transformers into the
containers and the withdrawal operation of the instrumentation
transformers from the containers.
[0006] The present invention is characterized by such an
arrangement of plural instrumentation transformers for measuring
the voltage in the main circuit as located within the container in
the midst of containers arranged together.
[0007] According to the above described embodiment, as plural
instrumentation transformers are arranged within the container
located in the midst of the center among the containers arranged
together, the installation operation of the instrumentation
transformers into the containers and the withdrawal operation of
the instrumentation transformers 6a to 6d from the containers may
be applied only to the container 15b, and the installation and
withdrawal operation at the other containers may be done simply by
wiring the primary-side lead lines. Owing to this configuration,
the work load and work time for the installation operation of the
instrumentation transformers 6a to 6d into the containers and the
withdrawal operation the instrumentation transformers 6a to 6d from
the containers can be reduced to a large extent.
[0008] According to the present invention, it is easy to route the
primary-side lead line of the instrumentation transformer from the
container located a the center to the containers located at both
ends. That is, in case that the instrumentation transformers are
installed in the containers located at both ends, there occurs a
part in which a couple of primary-side lead lines for the
instrumentation transformers are required to be routed. As it is
necessary to establish an enough insulation distance between two
lead lines in this configuration, the structure of routing the
primary-side lead lines may be complicated or the container may be
upsized. In contrast, in this invention, as plural instrumentation
transformers are arranged within the container located in the midst
among the containers, the primary-side lead lines for the
instrumentation transformers can be accommodated by a single cable
extended from the container located in the midst to the containers
located at both ends. Thus, it will be appreciated that the
complexity in the routing configuration for the primary-side lead
lines and the upsizing of the containers can be reduced.
[0009] A couple of coadjacent containers among three containers
arranged together are linked by an insulating tube. The
primary-side lead line of the instrumentation transformer
corresponding to the phase for the containers located at both ends
of three containers arranged together is made routed from the
container located in the midst among three containers through the
insulating tube to the corresponding container located at one of
both ends of containers. The reason why the insulation tube is used
for linking the containers is to prevent the cyclic current from
flowing between the containers.
[0010] A breaker part of the disconnecting switch for disconnecting
electrically the main circuit is installed at the individual
containers arranged together. The breaker part is insulated by the
insulating gas such as sulfur hexafluoride, and has a contact
makers operated by the manipulator so as to contact to and leave
from each other. A switching part of the disconnecting switch, a
switching part of the earthing switch and an arrestor, connected
electrically to the main circuit, are arranged in three containers
arranged together, individually.
[0011] The height of the container located in the midst among three
containers arranged together is made larger than the height of the
other containers in order to establish an enough insulation
distance between plural instrumentation transformers and the other
components. The primary-side of plural instrumentation transformers
is configured with open-delta connection or star connection. The
plural instrumentation transformers are supported so as to be
suspended down from the ceiling board installed above the
container. The arresters are also supported so as to be suspended
down from the ceiling board installed above the container.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a cross-sectional drawing illustrating the
structure of the switchgear as the first embodiment of the present
invention.
[0013] FIG. 2 is a cut-away drawing at the line II-II of FIG.
1.
[0014] FIG. 3 is a cut-away drawing at the line III-III of FIG.
[0015] FIG. 4 is a three-phase connection diagram of the switchgear
as the first embodiment of the present invention.
[0016] FIG. 5 is a cross-sectional drawing illustrating the
structure of the switchgear as the second embodiment of the present
invention.
[0017] FIG. 6 is a cut-away drawing at the line III-III of FIG.
5.
[0018] FIG. 7 is a three-phase connection diagram of the switchgear
as the second embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] By referring to attached figures, the embodiment of the
present invention is disclosed.
[0020] FIG. 4 shows a three-phase connection diagram of the
switchgear in the first embodiment of the present invention. The
switchgear of this embodiment is a substation component for the
power generator installed in the power plants such as thermal
electric power plants, nuclear power plants and hydro-electric
power plants, which is used for breaking the heavy current in the
main circuit from the power generator to the transformers. This
switchgear comprises separated components for the individual
phases, U-phase, V-phase and W-phase, respectively.
[0021] Incidentally, in the hypo-description, in case where the
arrangements of the phases of three are the same, in order to avoid
reduplicated description, any one of the phases of three (the
U-phase in the hypo-description on the present embodiments) is
typically explained. Corresponding reference characters of the
other phases are shown in parenthesis, and the explanation of there
arrangements is omitted.
[0022] A component 1a (1b, 1c) in the figure is a switchgear
installed in the U-phase (V-phase, W-phase) circuit. The switchgear
1a (1b, 1c) is used for breaking electrically the current flow in
the U-phase (V-phase, W-phase).
[0023] The disconnecting switch 2a (2b, 2c) is connected to the
transformerside of the switchgear 1a (1b, 1c). The disconnecting
switch 2a (2b, 2c) isolates electrically the U-phase circuit into
the generator-side circuit and the transformer-side circuit. The
generator-side circuit is a circuit located between the switchgear
1a (1b, 1c) and the power generator, and corresponds to the circuit
including the switchgear 1a (1b, 1c). The transformer-side circuit
is a circuit located between the switchgear 1a (1b, 1c) and the
transformer, and corresponds to the circuit excluding the
switchgear 1a (1b, 1c).
[0024] The earthing switch 3a (3b, 3c) and the arrester 4a (4b, 4c)
are connected electrically to the transformer-side of the
disconnecting switch 2a (2b, 2c). The earthing switch 3a (3b, 3c)
is used for reducing the circuit voltage at the transformer-side
down to the earthing electric potential and one of its terminal is
grounded. The arrester 4a (4b, 4c) is used for regulating the
overvoltage transferred to the circuit forU-phase (V-phase,
W-phase), anditsoneterminal isgrounded.
[0025] The earthing switch 5a (5b, 5c) is connected electrically to
the transformer-side of the disconnecting switch 1a (1b, 1c). The
earthing switch 5a (5b, 5c) is used for reducing the circuit
voltage at the generator-side down to the earthing electric
potential and one of its terminal is grounded.
[0026] One terminal of the primary side of the instrumentation
transformer 6a is connected electrically to the generator-side of
the disconnecting switch 1a. The other terminal of the primary side
of the instrumentation transformer 6b and one of the primary side
of the instrumentation transformer 6c are connected electrically to
the generation-side of the disconnecting switch 1b. The other
terminal of the primary side of the instrumentation transformer 6d
is connected electrically to the generation-side of the
disconnecting switch 1c.
[0027] The other terminal of the primary side of the
instrumentation transformer 6a is connected electrically in series
connection to one terminal of the primary side of the
instrumentation transformer 6b. The other terminal of the primary
side of the instrumentation transformer 6c is connected
electrically in series connection to one terminal of the primary
side of the instrumentation transformer 6d.
[0028] The instrumentation transformers 6a to 6d are used for
measuring the circuit voltage of U-phase to W-phase, and are
composed with open-delta connection.
[0029] Though not shown in this figure, a feeding disconnecting
switch is connected electrically to the generator-side of the
disconnecting switches 1a to 1c. The instrumentation transformers
for the disconnecting switches 2a to 2c are connected to the
transformer-side of the disconnecting switches 1a to 1c.
[0030] FIGS. 1 to 3 illustrate the structure of the switchgear
implemented with the three-phase connection diagram shown in FIG.
4. A component 10 in the figure is a base pedestal. A storage space
is located above the base pedestal 10. Link mechanism parts 12a to
12c are contained in the storage space 13, which are connected
mechanically through the coupling rod 11 to the manipulator (not
shown). A manipulator box 14 is installed on the top and edge of
the base pedestal 10 and at one end side of the storage space 13.
The manipulator is used for making the contact makers of the
disconnecting parts of the disconnecting switches 1a to 1c
contacted and released on the block. The manipulator box 14 is
taller than the storage space 13.
[0031] Containers 15a to 15c are arranged in the extended direction
of the coupling rod 11 above the storage space 13. The width of the
individual containers 15a to 15c is defined to be identical to each
other, and the depth of the individual containers 15a to 15c is
defined to be identical to each other. Its width is smaller than
its depth. The width of the container is defined as the dimension
of the container measured in the extended direction of the coupling
rod 11. The depth of the container is defined as the dimension of
the container measured in the vertical direction with respect to
the extended direction of the coupling rod 11. The height of the
container 15a is defined to be the same as the height of the
container 15c. The height of the container 15b is defined to be
higher than the height of the containers 15a and 15c.
[0032] The container 15a (15b, 15c) is composed of a base plate 16a
(16b, 16c), a side wall 17a (17b, 17c) and a roof 18a (18b, 18c),
and thus forms a gable-roof shaped box. The container 15a (15b,
15c) is made of metal, and made grounded. A gable-roof shape is
such a shape of roof as a couple of plates are coupled to each
other and as its side projection looks like "", one of Japanese
Hiragana characters. A gable-roof shaped box means a box having a
gable roof.
[0033] A ceiling board 19a (19b, 19c) is installed at the roof side
18a (18b, 18c) of the side wall 17a (17b, 17c). The ceiling board
19a (19b, 19c) is used for supporting the pendant instrument
transformer and arrestor as described later. A container box 20a
(20b, 20c) is installed below the under surface of the base plate
16a (16b, 16c). The container box 20a (20b, 20c) is used for
containing the link mechanism 12a (12b, 12c) extended down below
the base plate 16a (16b, 16c).
[0034] An insulating tube 21a for coupling between the container
15a and the container 15b is installed between the side wall 17a
and the side wall 17b. An insulating tube 21b for coupling between
the container 15b and the container 15c is installed between the
side wall 17b and the side wall 17c. The insulating tubes 21a ad
21b are used as wiring ducts for routing the primary side lead
wires for the instrumentation transformer to be described later,
from the container 15b to the containers 15a and 15c.
[0035] The breaker part 22a (22b, 22c) of the disconnecting switch
1a (1b, 1c) is installed within the container 15a (15b, 15). The
breaker part 22a (22b, 22c) is enclosed by the main circuit
conductor 23a (23b, 23c), the main circuit conductor 24a (24b, 24c)
and the insulating member 25a (25b, 25c), which is formed by
arranging the switching mechanism part 26a (26b, 26c) at the part
where the insulating gas such as sulfur hexafluoride (SF6) are
filled.
[0036] The main circuit conductor 24a (24b, 24c) and the main
circuit conductor 24a (24b, 24c) are cylindrical members having
electric conductivity. The main circuit conductor 24a (24b, 24c) is
insulated and supported by the insulating and supporting member 27a
(27b, 27c) fixed at the base plate 16a (16b, 16c). The main circuit
conductor 24a (24b, 24c) is insulated and supported by the
insulating and supporting member 28a (28b, 28c) fixed at the base
plate 16a (16b, 16c).
[0037] The insulating member 25a (25b, 25c) is a cylindrical member
formed between the main circuit conductor 23a (23b, 23c) and the
main circuit conductor 24a (24b, 24c), which is used for insulating
electrically the main circuit conductor 23a (23b, 23c) from the
main circuit conductor 24a (24b, 24c), and vice versa.
[0038] The switching mechanism part 26a (26b, 26c) is composed of
the fixed switching mechanism part 29a (29b, 29c) and the movable
switching mechanism part 30a (30b, 30c). The fixed switching
mechanism part 29a (29b, 29c) is fixed on the surface of the flange
standing out from the peripheral surface of the breaker part 23a
(23b, 23c) to its inside in the radial direction, and a stick and
fixed contact maker is installed on its central axis. the movable
switching mechanism part 30a (30b, 30c) is fixed on the surface of
the flange standing out fromthe peripheral surface of the breaker
part 24a (24b, 24c) to its inside in the radial direction so as to
face in an opposed position to the fixed switching mechanism part
29a (29b, 29c). At the center part of the movable switching
mechanism part 30a (30b, 30c), a movable contact maker is installed
so as to be enable to contact to and leave from the fixed contact
maker of the fixed switching mechanism part 29a (29b, 29c).
[0039] One side of the link mechanism 12a (12b, 12c) is connected
mechanically to the movable contact maker of the movable switching
mechanism part 30a (30b, 30c) at its opposite side to the fixed
switching mechanism part 29a (29b, 29c). The link mechanism 12a
(12b, 12c) is formed as a unit of mechanical components coupled
mechanically to one another such as insulating rod, revolving shaft
lever and operation rod, which reaches the inside of the
current-carrying conductor 27a (27b, 27c) from the inside of the
container box 20a (20b, 20c) through the hollow part formed in the
insulating and supporting member 28a (28b, 28c). Hexafluoride (SF6)
gas as the insulating gas is filled in the hollow part of the
insulating and supporting member 28a (28b, 28c) and the inside of
the container box 20a (20b, 20c).
[0040] The switchgear 1a (1b, 1c) in this embodiment is configured
as a puffer so that the arc generated when opening the movable
contact maker from the fixed contact maker may be extinguished by
spraying the compressed hexafluoride gas used as insulating
material at the breaker part 22a (22b, 22c).
[0041] The switching part 31a (31b, 31c) of the disconnecting
switch 2a (2b, 2c) is placed on the coaxial line shared by the
breaker part 22a (22b, 22c) of the disconnecting switch 1a (1b,
1c). The switching part 31a (31b, 31c) is formed by arranging the
switching mechanism part 34a (34b, 34c) at the area enclosed by the
main circuit conductor 24a (24b, 24c), the main circuit conductor
32a (32b, 32c) and the insulating member 25a (25b, 25c). The
switching mechanism part 34a (34b, 34c) is insulated by air not
like the switching mechanism part 26a (26b, 26c) of the breaker
part 22a (22b, 22c).
[0042] The main circuit conductor 32a (32b, 32c) is a conductive
member shaped in a cylinder. The main circuit conductor 32a (32b,
32c) is insulated and supported by the insulation and supporting
member 35a (35b, 35c) fixed at the base plate 16a (16b, 16c). The
insulating member 33a (33b, 33c) is a member shaped in a cylinder
installed between the main circuit conductor 24a (24b, 24c) and the
main circuit conductor 32a (32b, 32c), and is used for insulating
electrically between the main circuit conductor 24a (24b, 24c) and
the main circuit conductor 32a (32b, 32c).
[0043] The switching mechanism part 34a (34b, 34c) is composed of
the fixed switching mechanism part 36a (36b, 36c) and the movable
switching mechanism part 37a (37b, 37c). The fixed switching
mechanism part 36a (36b, 36c) is connected electrically to the main
circuit conductor 24a (24b, 24c) and has a fixed contact maker. The
movable switching mechanism part 37a (37b, 37c) is on the surface
of the flange standing out from the peripheral surface of the main
circuit conductor 32a (32b, 32c) to its inside in the radial
direction so as to be opposed to the fixed switching mechanism part
36a (36b, 36c). The central part of the movable switching mechanism
part 37a (37b, 37c) contains a movable contact maker configured so
as to be enabled to contact to and leave from the fixed contact
maker of the fixed switching mechanism part 36a (36b, 36c) in the
horizontal direction.
[0044] One side of the link mechanism 38a (38b, 38c) is connected
mechanically to the movable contact maker of the movable switching
mechanism part 37a (37b, 37c) at its opposite side to the fixed
switching mechanism part 38a (38b, 38c). The link mechanism 38a
(38b, 38c) is formed as a unit of mechanical components coupled
mechanically to one another such as insulating rod, revolving shaft
lever and operation rod. The other side of the link mechanism 38a
(38b, 38c) extends below the base plate 16a (16b, 16c), and is
connected mechanically to the manipulator (not shown) for the
disconnecting switch, contained in the container box 13.
[0045] The fixed contact maker 40a (40b, 40c) of the earthing
switch5a (5b, 5c) is connected electrically to the main circuit
conductor 23a (23b, 23c) through the conductive member 39a (39b,
39c). The movable contact maker 41a (41b, 41c) installed so as to
be enabled to contact to and leave from the fixed contact maker 40a
(40b, 40c) is placed below the fixed contact maker 40a (40b, 40c)
in the vertical direction and at the opposed position to the fixed
contact maker 40a (40b, 40c). A pair of the fixed contact maker 40a
(40b, 40c) and the movable contact maker 41a (41b, 41c) forms the
switching part 42a (42b, 42c) of the earthing switch 5a (5b, 5c).
The movable contact maker 41a (41b, 41c) is operated by the
manipulator (not shown) for the earthing switch contained in the
container box 13.
[0046] The fixed contact maker 44a (44b, 44c) of the feeding
disconnecting switch is connected electrically to the main circuit
conductor 23a (23b, 23c) through the conductive member 43a (43b,
43c). Themovablecontactmaker45a (45b, 45c) installed so as to be
enabled to contact to and leave from the fixed contact maker 44a
(44b, 44c) is placed below the fixed contact maker 44a (44b, 44c)
in the vertical direction and at the opposed position to the fixed
contact maker 44a (44b, 44c). A pair of the fixed contact maker 44a
(44b, 44c) and the movable contact maker 45a (45b, 45c) forms the
switching part 46a (46b, 46c) of the feeding disconnecting switch.
The movable contact maker 45a (45b, 45c) is operated by the
manipulator (not shown) for the feeding disconnecting switch
contained in the container box 13.
[0047] The fixed contact maker (not shown) of the earthing switch
3a (3b, 3c) is connected electrically to the main circuit conductor
32a (32b, 32c) through the conductive member (not shown). The
movable contact maker (not shown) installed so as to be enabled to
contact to and leave from the fixed contact maker is placed below
the fixed contact maker in the vertical direction and at the
opposed position to the fixed contact maker. A pair of the fixed
contact maker and the movable contact maker forms the switching
part of the earthing switch 3a (3b, 3c). The movable contact maker
is operated by the manipulator (not shown) for the earthig switch
contained in the container box 13.
[0048] At one side of the ceiling board 19a (19b, 19c) (at the side
of the switching part 31a (31b, 31c) of the disconnecting switch 2a
(2b, 2c)), the instrumentation transformer 47a (47b, 47c) and the
arrester 4a (4b, 4c) are arranged along the line on which the
containers 15a to 15c are installed. The instrumentation
transformer 47a (47b, 47c) and the arrester 4a (4b, 4c) are
supported so as to be suspended down from the ceiling board 19a
(19b, 19c). The instrumentation transformer 47a (47b, 47c) is used
for measuring the circuit voltage of U-phase (V-phase, W-phase)
used for operating the switching part 33a (33b, 33c) of the
disconnecting switch 2a (2b, 2c), and its primary lead line is
connected electrically to the connector 48a (48b, 48c) formed at
the main circuit conductor 32a (32b, 32c). The arrester 4a (4b, 4c)
is used for regulating the over voltage to be propagated to the
circuit of U-phase (V-phase, W-phase).
[0049] The instrumentation transformers 6a to 6d are installed at
the other side of the ceiling board 19b (at the side of the breaker
part 1b of the switchgear 1b). The instrumentation transformers 6a
to 6d are arranged lengthwise and breadthwise in two columns so as
to be suspended from the ceiling board 19b. The instrumentation
transformers 6a to 6d are used for measuring the circuit voltage of
U-phase to W-phase to be used for operating the breaker part 22a
(22b, 22c) of the disconnecting switch 1a (1b, 1c). The
instrumentation transformers 6a to 6d are composed of the core part
having the primary winding and the secondary winding and insulated
by the insulating gas or the insulating oil, and four conductive
terminals extending down below the core part and insulated by the
insulating material such as epoxy resin. Two of four conductive
terminals form the primary-side terminals and the rest of the
conductive terminals form the secondary-side terminals.
[0050] The primary-side lead line 49 connected electrically to one
side of the primary-side terminal of the instrumentation
transformer 6a is routed from the inside of the container 15b
through the insulating tube 21a to the inside of the container 15a,
and is connected electrically to the terminal 52a installed in the
main circuit conductor 23a. The other side of the primary-side
terminal of the instrumentation transformer 6a and one side of the
primary-side terminal of the instrumentation transformer 6b are
connected electrically in series connection. Though not shown in
the figure, the primary-side lead line 49 is supported by the
insulating support member mounted at the ceiling board 19a.
[0051] The primary-side lead line 51 connected electrically to one
side of the primary-side terminal of the instrumentation
transformer 6d is routed from the inside of the container 15b
through the insulating tube 21b to the inside of the container 15c,
and is connected electrically to the terminal 52c installed in the
main circuit conductor 23c. The other side of the primary-side
terminal of the instrumentation transformer 6d and one side of the
primary-side terminal of the instrumentation transformer 6c are
connected electrically in series connection. Though not shown in
the figure, the primary-side lead line 51 is supported by the
insulating support member mounted at the ceiling board 19c.
[0052] The primary-side lead line 50 connected electrically to the
other side of the primary-side terminal of the instrumentation
transformer 6b and to one side of the primary-side terminal of the
instrumentation transformer 6c is connected electrically to the
terminal 52b installed in the main circuit conductor 23b. The
secondary-side lead line (not shown) connected electrically to the
secondary-side terminal of the instrumentation transformers 6a to
6d is connected electrically to the instrumentation device.
[0053] According to the above described embodiment, as the
instrumentation transformers 6a to 6d are arranged within the
container 15b which is located in the midst of the center among the
containers 15a to 15c arranged together, the installation operation
of the instrumentation transformers 6a to 6d into the containers
and the withdrawal operation of the instrumentation transformers 6a
to 6d from the containers may be applied only to the container 15b,
and the installation and withdrawal operation at the other
containers may be done simply by wiring the primary-side lead
lines. Owing to this configuration, the work load and work time for
the installation operation of the instrumentation transformers 6a
to 6d into the containers and the withdrawal operation the
instrumentation transformers 6a to 6d from the containers can be
reduced to a large extent, which may leads to an increase in the
working efficiency for the installation operation of the
instrumentation transformers 6a to 6d into the containers and the
withdrawal operation the instrumentation transformers 6a to 6d from
the containers. Thus, the working efficiency for the assembly
operation of the switchgear and the replacement operation of the
instrumentation transformers 6a to 6d can be increased.
[0054] The installation operation of the instrumentation
transformers 6a to 6d into the containers is performed as follows.
At first, the instrumentation transformers 6a to 6d are made
mounted on the ceiling board 19b. Next, the ceiling board 19b is
made lifted by the crane, and mounted at the side wall 17b of the
container 19b. Then, the wiring operation for the primary-side lead
lines are performed for the containers 15a to 15c. The removal
operation of the instrumentation transformers 6a to 6d from the
containers is performed by applying the above installation
procedures in reverse order.
[0055] According to this embodiment, the primary-side lead line 49
connected electrically to the primary-side terminal of the
instrumentation transformer 6a and the primary-side lead line 51
connected electrically to the primary-side terminal of the
instrumentation transformer 6d can be routed easily from the
container 15b to the containers 15a and 15d. In case that the
instrumentation transformers are installed within the containers
15a and 15c, there occurs such a part that a couple of primary-side
lead lines connected electrically to the primary-side of the
instrumentation transformer are required to be routed, which leads
to increasing the complexity of cable routing or to upsizing the
containers. In this embodiment, on the contrary, as the
instrumentation transformers 6a to 6d are installed within the
container 15b, a single cable routed from the container 15b to the
containers 15a and 15c can accommodate the primary-side lead line
49 connected electrically to the primary-side terminal of the
instrumentation transformer 6a and the primary-side lead line 51
connected electrically to the primary-side terminal of the
instrumentation transformer 6d, which leads to reducing the
complexity of cable routing or to downsizing the containers. Thus,
the economical efficiency of the switchgear can be increased.
[0056] According to this embodiment, as the insulating tube 21a is
linked between the container 15a and the container 15b and the
insulating tube 21a is linked between the container 15b and the
container 15c, cyclic currents do not flow among the containers.
Owing to this configuration, it will be appreciated that the heat
build-up at the containers 15a to 15c can be reduced. Thus, the
safety of the switchgears can be increased.
[0057] FIG. 7 shows a three-phase connection diagram of the
switchgear in the second embodiment of the present invention. In
this embodiment, the instrumentation transformers 7a to 7d are used
for measuring the circuit voltage of U-phase to W-phase, and their
primary-side is composed with star-connection. The component parts
identical to those in the previous embodiment have like numbers and
their detail description is not repeated here.
[0058] One terminal of the primary side of the instrumentation
transformer 7a is connected electrically to the generator-side of
the disconnecting switch 1a. One terminal of the primary side of
the instrumentation transformer 6c is connected electrically to the
generation-side of the disconnecting switch 1b. One terminal of the
primary side of the instrumentation transformer 6e is connected
electrically to the generation-side of the disconnecting switch
1c.
[0059] The other terminal of the primary side of instrumentation
transformer 7a and one terminal of the primary side of the primary
side of instrumentation transformer 7b are connected electrically
in series. The other terminal of the primary side of
instrumentation transformer 7c and one terminal of the primary side
of the primary side of instrumentation transformer 7d are connected
electrically in series. The other terminal of the primary side of
instrumentation transformer 7e and one terminal of the primary side
of the primary side of instrumentation transformer 7d are connected
electrically in series. The other terminal of the primary side of
instrumentation transformer 7b and the other terminal of the
primary side of the primary side of instrumentation transformer 7d,
and the other terminal of the primary side of the primary side of
instrumentation transformer 7f are connected electrically in
series.
[0060] FIG. 5 and FIG. 6 illustrate the structure of the switchgear
implemented with the three-phase connection diagram shown in FIG.
7. The component parts identical to those in the previous
embodiment have like numbers and their detail description is not
repeated here. In this embodiment, as in the previous embodiment,
the instrumentation transformers 7a to 7f are mounted at the other
side (at the breaker part 22a side of the disconnecting switch 1a)
of the ceiling board 19b within the container 15b.
[0061] The instrumentation transformers 7a to 7f are used for
measuring the circuit voltage of U-phase to W-phase to be used for
operating the breaker part 22a (22b, 22c) of the disconnecting
switch 1a (1b, 1c), and are arranged in two columns lengthwise for
the container 15d and in three columns breadthwise for the
container 15 so as to be suspended from the ceiling board 19b. The
instrumentation transformers 7a to 7d are composed of the core part
having the primary winding and the secondary winding and insulated
by the insulating gas or the insulating oil, and two conductive
terminals (primary-side terminals) and two secondary-side terminals
extending down below the core part and insulated by the insulating
material such as epoxy resin.
[0062] The primary-side lead line 53 connected electrically to one
side of the primary-side terminal of the instrumentation
transformer 7a is routed from the inside of the container 15b
through the insulating tube 21a to the inside of the container 15a,
and is connected electrically to the terminal 52a installed in the
main circuit conductor 23a. The other side of the primary-side
terminal of the instrumentation transformer 7a and one side of the
primary-side terminal of the instrumentation transformer 7b are
connected electrically in series connection. Though not shown in
the figure, the primary-side lead line 53 is supported by the
insulating support member mounted at the ceiling board 19a.
[0063] The primary-side lead line 54 connected electrically to one
side of the primary-side terminal of the instrumentation
transformer 7c is connected electrically to the terminal 52b
installed in the main circuit conductor 23b. The other terminal of
the primary side of instrumentation transformer 7c and one terminal
of the primary side of the primary side of instrumentation
transformer 7d are connected electrically in series.
[0064] The primary-side lead line 55 connected electrically to one
side of the primary-side terminal of the instrumentation
transformer 7e is routed from the inside of the container 15b
through the insulating tube 21b to the inside of the container 15c,
and is connected electrically to the terminal 52c installed in the
main circuit conductor 23c. The other side of the primary-side
terminal of the instrumentation transformer 7e and one side of the
primary-side terminal of the instrumentation transformer 7f are
connected electrically in series connection. Though not shown in
the figure, the primary-side lead line 55 is supported by the
insulating support member mounted at the ceiling board 19c.
[0065] The other side of the primary-side terminal of the
instrumentation transformer 7b the other side of the primary-side
terminal of the instrumentation transformer 7d and the other side
of the primary-side terminal of the instrumentation transformer 7f
are connected electrically in series connection. The secondary-side
lead line (not shown) connected electrically to the secondary-side
terminal of the instrumentation transformers 6a to 6d is connected
electrically to the instrumentation device.
[0066] According to the above described embodiment, as the
instrumentation transformers 7a to 7f are arranged within the
container 15b which is in the midst of the center among the
container 15a to 15c, the working efficiency for the installation
operation of the instrumentation transformers 7a to 7f into the
containers and the withdrawal operation of the instrumentation
transformers 7a to 7f from the containers may be increased. Thus,
the working efficiency for the assembly operation of the switchgear
and the replacement operation of the instrumentation transformers
7a to 7f can be increased.
[0067] In addition, according to this embodiment, as the
instrumentation transformers 7a to 7f are installed within the
container 15b, a single cable routed from the container 15b to the
containers 15a and 15c can accommodate the primary-side lead line
53 connected electrically to the primary-side terminal of the
instrumentation transformer 7a and the primary-side lead line 55
connected electrically to the primary-side terminal of the
instrumentation transformer 6e, which leads to reducing the
complexity of cable routing or to downsizing the containers. Thus,
the economical efficiency of the switchgear can be increased.
[0068] According to the present invention, as the working load and
working time for the installation operation of the instrumentation
transformers into the containers and the withdrawal operation of
the instrumentation transformers from the containers can be reduced
to a large extent, the working efficiency for the installation
operation of the instrumentation transformers into the containers
and the withdrawal operation of the instrumentation transformers
from the containers can be increased. Thus, the working efficiency
for the assembly operation of the switchgear and the replacement
operation of the instrumentation transformers can be increased. In
addition, according to the present invention, as the complexity of
cable routing or the upsizing of the containers can be reduced, the
economical efficiency of the switchgear can be increased. The
routing of the primary-side lead lines of the instrumentation
transformers can be accommodated in a single cable independently
upon the connection method for the primary-side lead lines of the
instrumentation transformers.
* * * * *