DESCRIPTION
[Title of the Invention]
SWITCHGEAR
5 [Technical Field]
10
This invention relates to switchgears and is particularly
suitable for switchgears having an air-insulated earthing
disconnecting switch that performs closing, disconnecting, and
earthing operations with air insulation.
[Background Art]
Japanese Unexamined Patent Application Publication No.
2 011-414 07 (Patent Literature 1) discloses an example of typical
switchgears that include an air-insulated earthing
15 disconnecting switch performing closing, disconnecting, and
earthing operations with air insulation, but are still compact
even though employing air insulation.
This switchgear disclosed in the Patent Literature 1
includes an air-insulated earthing disconnecting switch that
20 linearly moves and is swi tchable among three positions, i.e.,
a closing position, a disconnecting position, and an earthing
position, a vacuum interrupter that applies or interrupts
voltage and current in a vacuum chamber maintained under vacuum,
and a solid insulator that encloses the air-insulated earthing
25 disconnecting switch and the vacuum interrupter. The
5
2
switchgear is also characterized in that the air-insulated
earthing disconnecting switch is electrically connected to the
vacuum interrupter, and application and interruption of voltage
and current are performed inside the vacuum interrupter.
In addition, the switchgear described in the Patent
Literature 1 is operated as follows: application of voltage
and current to a high-voltage circuit, such as a cable, is made
by closing the vacuum interrupter after the air-insulated
earthing disconnecting switch is brought into conduction;
10 interruption of voltage and current is made by opening the vacuum
interrupter while the air-insulated earthing disconnecting
switch is in conduction; disconnection of the high-voltage
circuit is made by switching the air-insulated earthing
disconnecting switch to the disconnecting position after
15 voltage and current are interrupted; and earthing of the
high-voltage circuit is made by switching the air-insulated
earthing disconnecting switch to the earthing position after
the high-voltage circuit is disconnected, and then closing the
vacuum interrupter.
20
[Citation List]
[Patent Literature]
[Patent Literature 1] JP-A No. 2011-41407
25 [Summary of Invention]
3
[Technical Problem]
However, the switchgear as disclosed in the
aforementioned Patent Literature 1 is configured so that the
accuracy of three positions for closing, disconnecting, and
5 earthing, more specifically, the dimensional accuracy of a gap
between contacts at the closing, disconnecting, and earthing
positions, affects insulation performance. Thus, further
study on control is needed to improve the dimensional accuracy
of a gap between the contacts.
10 The present invention has been made in view of the above
points and provides a switchgear that has improved stopping
accuracy at three positions, i.e., a closing position, a
disconnecting position, and an earthing position, thereby
stabilizing insulation performance.
15 [Solution to Problem]
The switchgear according to the invention includes an
air-insulated earthing disconnecting switch that linearly
moves and is swi tchable among a closing position, a disconnecting
position, and an earthing position, a vacuum interrupter that
20 is electrically connected to the air-insulated earthing
disconnecting switch and makes and breaks current flow in a
vacuum chamber maintained under vacuum, and an operating device
that provides driving force to movable electrodes of the
air-insulated earthing disconnecting switch and the vacuum
25 interrupter. The air-insulated earthing disconnecting switch
4
and the vacuum interrupter are integrally covered with a solid
insulation. The operating device of the air-insulated earthing
disconnecting switch transmits driving force from a motor to
the air-insulated earthing disconnecting switch via an
5 operating-force transmission unit. The operating-force
transmission unit includes an operation rod fixedly coupled
to the movable electrode of the air-insulated earthing
disconnecting switch, a lever making an arc motion with a shaft
rotatably driven by the motor, a coupling pin coupling the lever
10 and the operation rod, and limit switches detecting that the
air-insulated earthing disconnecting switch is in the closing
position, disconnecting position, or earthing position by means
of the coupling pin driven by the operation of the rod operating
with an arc motion of the lever.
15 [Advantageous Effects of Invention]
20
25
The present invention can provide a switchgear that has
improved stopping accuracy at three positions, i.e., a closing
position, a disconnecting position, and an earthing position,
thereby stabilizing insulation performance.
[Brief Description of Drawings]
FIG. 1 is a schematic diagram showing the configuration
of a switchgear according to an embodiment of the present
invention;
FIG. 2 is a schematic diagram showing details of an
5
operating-force transmission unit of an air-insulated earthing
disconnecting switch of the switchgear according to the
embodiment of the invention;
FIG. 3 is a perspective view showing details of the
5 operating-force transmission unit of the air-insulated
earthing disconnecting switch of the switchgear according to
the embodiment of the invention; and
FIG. 4 is a front view of FIG. 3.
10 [Description of Embodiments]
15
With reference to an illustrated embodiment, a switchgear
according to the embodiment of the present invention will be
described below.
[Embodiment]
FIGS. 1 to 4 show a vacuum insulated switchgear which
is a switchgear according to the embodiment of the invention.
As shown in FIGS. 1 to 4, the vacuum insulated switchgear
1 of the embodiment mainly includes a mold switch 2, an operating
device 3, and an operating-force transmission unit 4. The
20 following are descriptions of those inclusions.
The mold switch 2 includes a vacuum interrupter 5 having
the functions of closing and breaking in vacuum insulation and
a three-position air-insulated earthing disconnecting switch
6 having the functions of closing, disconnecting, and earthing.
25 The interrupter 5 and switch 6 are covered with a solid insulator
6
27 of epoxy or the like. The vacuum interrupter 5 is electrically
connected to the air-insulated earthing disconnecting switch
6 with a flexible conductor 13.
The air-insulated earthing disconnecting switch 6 has
5 a first fixed electrode 7 that is connected to a busbar-side
conductor (not shown) in a busbar mold bushing 10 connected
to a bus bar. The air-insulated earthing disconnecting switch
6 has a second fixed electrode 8 that is connected to a movable
conductor 14 of the vacuum interrupter 5 through the flexible
10 conductor 13 connected therebetween. Furthermore, the
air-insulated earthing disconnecting switch 6 has a third fixed
electrode 9 that is earthed.
The inner circumferences of the first fixed electrode
7, second fixed electrode 8, and third fixed electrode 9 of
15 the air-insulated earthing disconnecting switch 6 are aligned
along the same cylinder. An air movable electrode 43 in a shape
corresponding to the cylinder slides along the inner
circumferences of the respective fixed electrodes. The air
movable electrode 43 is connected to an air-insulated operation
20 rod 62 made from an insulating member. This air-insulated
operation rod 62 is connected to an operation rod 63 linked
to the operating device 3.
The vacuum interrupter 5 includes a fixed electrode 11,
a movable electrode 12 facing the fixed electrode 11, a fixed
25 conductor 19 connected to the fixed electrode 11, and a movable
5
7
conductor 14 connected to the movable electrode 12. The fixed
electrode 11 and movable electrode 12 are surrounded by an arc
shield 18 to prevent a vacuum chamber 20 from being damaged
by arc vapor.
In the vacuum interrupter 5, a vacuum chamber 20 is
maintained under vacuum. A bellows 15 provided between the
vacuum chamber 20 and the movable conductor 14 allows the movable
conductor 14 to operate while maintaining the vacuum chamber
20 under vacuum. The fixed conductor 19 is connected to a feeder
10 conductor 33 that has an end provided with a mold bushing 16
molded with an insulation material. In addition, a voltage
detector 17 is connected to a middle part of the feeder conductor
33 to make it possible to measure voltage to be applied to a
load. Outside of the vacuum chamber 20, the movable conductor
15 14 is connected to the flexible conductor 13, which is connected
to the second fixed electrode 8 of the air-insulated earthing
disconnecting switch 6, and also is connected to an air- insulated
operation rod 52, which is made from an insulating member and
used with the vacuum interrupter 5. The air-insulated
20 operation rod 52 is connected to an operation rod 53 for the
vacuuminterrupter5,disposedonthesideoftheoperating-force
transmission unit 4.
The busbar-side conductor (not shown) in the busbar mold
bushing 10, the first fixed electrode 7 and the second fixed
25 electrode 8 of the air-insulated earthing disconnecting switch
8
6, the vacuum chamber 20 and the feeder conductor 33 are
integrally molded with an insulation material of epoxy or the
like, which forms the solid insulator 27. Further, the solid
insulator 27 is formed to surround the air-insulated operation
5 rods 52, 62 with a space therebetween. However, the flexible
conductor 13 is not molded with the insulation material to
maintain its flexibility. The flexibility of the flexible
conductor 13 permits the movable conductor 14 that is connected
to the second fixed electrode 8 of the air-insulated earthing
10 disconnecting switch 6 to move in an axis direction.
The following describes the operating device 3. The
operating device 3 includes a motor 25 playing a role of an
operating instrument for the air-insulated earthing
disconnecting switch 6 and an operating instrument 2 6 for the
15 vacuum interrupter 5. The motor 2 5 provides driving force to
the air movable electrode 43 in the air-insulated earthing
disconnecting switch 6, while the operating instrument 26
provides driving force to the movable electrode 12 in the vacuum
interrupter 5.
20 Next, the operating-force transmission unit 4 will be
described. The operating-force transmission unit 4 is broadly
divided into a part on the vacuum interrupter 5 side and a part
on the air-insulated earthing disconnecting switch 6 side.
First, the operating-force transmission unit 4 on the
25 vacuum interrupter 5 side includes an
9
operating-instrument-side rod 55 connected to the operating
instrument 26, a main lever 50 connected to the
operating-instrument-side rod 55, a shaft (pivot) 51A connected
to the main lever 50, three-phase levers 51 connected to the
5 shaft 51A, and three-phase operation rods 53 respectively
connected to the three-phase levers 51. Each operation rod
53 is connected to the air-insulated operation rod 52 on the
vacuum interrupter 5 side.
The operating-force transmission unit 4 on the
10 air-insulated earthing disconnecting switch 6 side includes
a first chain 65A linked to a rotating shaft 25A of the motor
25, a first gear 66A engaged with the first chain 65A to transmit
the rotational energy of the motor 25 to a shaft 61A, a second
chain 658 linked to the shaft 61A, a second gear 668 engaged
15 with the second chain 658 to transmit the rotational energy
from the shaft 61A to an extended shaft 618, three-phase levers
61 connected to the extended shaft 618 and performing an arc
motion, three-phase operation rods 63 respectively connected
to the three-phase levers 61, and coupling pins 21 respectively
20 coupling each of the three-phase operation rods 63 to the
corresponding lever of the three-phase levers 61.
In addition, the operating-force transmission unit 4 on
the air-insulated earthing disconnecting switch 6 side
according to the embodiment includes a closing-position
25 detecting limit switch 22A, a disconnecting-position detecting
10
limit switch 228, and an earthing-position detecting limit
switch 22C. The rotational motion generated by the motor 25
is transmitted to the extended shaft 618 via the first chain
65A, first gear 66A, second chain 658, and second gear 668 and
5 causes the three-phase levers 61 coupled to the extended shaft
618 to perform an arc motion. The arc motion actuates the
operation rod 63 and resultantly drives the coupling pin 21
to allow the aforementioned limit switches to detect that the
air-insulated earthing disconnecting switch 6 is in the closing
10 position, disconnecting position, or earthing position.
The closing-position detecting limit switch 22A,
disconnecting-position detecting limit switch 228, and
earthing-position detecting limit switch 22C are attached to
a U-shaped guide hardware 23 that is disposed so as to surround
15 the coupling part where one of the three-phase levers 61 and
one of the three-phase operation rods 63 is coupled by the
coupling pin 21. The U-shaped guide hardware 23 has first
slotted holes 23A extending in a vertical direction formed in
the side walls opposite to each other. The coupling pin 21
20 moves in the first slotted holes 23A in the vertical direction
and comes into contact with the closing-position detecting limit
switch 22A, disconnecting-position detecting limit switch 228,
and earthing-position detecting limit switch 22C, respectively
arranged at positions corresponding to the closing position,
25 disconnecting position, and earthing position of the
5
11
air-insulated earthing disconnecting switch 6, thereby
detecting that the air-insulated earthing disconnecting switch
6isintheclosingposition, disconnectingposition, orearthing
position.
In addition, each of the three-phase levers 61 has an
end with a second slotted hole 61C extending in a longitudinal
direction of each of the three-phase levers 61. The coupling
pin 21 moves in the second slotted hole 61C operatively
associated with the arc motion of each of the three-phase levers
10 61 and also moves in the first slotted holes 23A in the vertical
direction, thereby causing the operation rod 63 to move
vertically.
Furthermore, oneclosing-positiondetectinglimitswitch
22A and one earthing-position detecting limit switch 22C are
15 disposed at positions corresponding to the closing position
and earthing position of the air-insulated earthing
disconnecting switch 6, respectively, while two
disconnecting-position detecting limit switches 22B are
disposed at positions corresponding to the disconnecting
20 position of the air-insulated earthing disconnecting switch
6.
More specifically, the closing-position detecting limit
switch 22A disposed at a position corresponding to the closing
position of the air-insulated earthing disconnecting switch
25 6 is arranged at an upper part of the U-shaped guide hardware
12
23. The disconnecting-position detecting limit switches 228
disposed at positions corresponding to the disconnecting
position of the air-insulated earthing disconnecting switch
6 are arranged at the center of both the side walls of the U-shaped
5 guide hardware 23, respectively. The earthing-position
detecting limit switch 22C disposed at a position corresponding
to the earthing position of the air-insulated earthing
disconnecting switch 6 is arranged at a lower part of the U-shaped
guide hardware 23.
10 In addition, in the vicinity of the first slotted holes
23A around which the closing-position detecting limit switch
22A, disconnecting-position detecting limit switch 228, and
earthing-position detecting limit switch 22C for the
air-insulated earthing disconnecting switch 6 are disposed,
15 rollers 24A, 248, 24C are set as integral parts of the limit
switches, respectively. When the coupling pin 21 makes contact
with the rollers 24A, 248, 24C, the rollers push to actuate
the closing-position detecting limit switch 22A,
disconnecting-position detecting limit switch 228, and
20 earthing-position detecting limit switch 22C disposed at
positions corresponding to the closing, disconnecting,
earthing positions of the air-insulated earthing disconnecting
switch.
According to the embodiment, the coupling pin 21 attached
25 to the operation rod 63 pushes the closing-position detecting
13
limit switch 22A when the air- insulated earthing disconnecting
switch 6 is in the closing position, pushes the
disconnecting-position detecting limit switch 22B when the
air-insulated earthing disconnecting switch 6 is in the
5 disconnecting position, and pushes the earthing-position
detecting limit switch 22C when the air-insulated earthing
disconnecting switch 6 is in the earthing position, thereby
detecting the each position of the air-insulated earthing
disconnecting switch 6.
10 In addition, a brake command is issued to the motor 25
in synchronization with a press of one of the closing-position
detecting limit switch 22A, disconnecting-position detecting
limit switch 228, and earthing-position detecting limit switch
22C for the air-insulated earthing disconnecting switch 6,
15 thereby stopping the motor 25.
During the time from the moment a limit switch is turned
on until a brake command reaches the motor 25, the motor 25
keeps running and also the coupling pin 21 keeps moving. By
employing a reduction gear designed to rotate at a lower speed
20 than the motor 25 to reduce the amount of movement of the coupling
pin 21 from when the closing-position detecting limit switch
22A, disconnecting-position detecting limit switch 228, and
earthing-position detecting limit switch 22C are turned on to
when the brake command reaches the motor 25, the coupling pin
25 21 can be controlled to stop at positions for closing,
14
disconnecting, and earthing with high accuracy.
The coupling pin 21 is configured so as to be capable
of moving downward at the closing position, both upward and
downward at the disconnecting position, and upward at the
5 earthing position.
Since the disconnecting-position detecting limit switch
22B adopts a roller mechanism that allows the coupling pin 21
to pass by both upwardly and downwardly, the coupling pin 21
presses in the disconnecting-position detecting limit switch
10 22B at different positions between when the coupling pin 21
moves from above to below and from below to above. More
specifically, the coupling pin 21 pressed down from above pushes
the roller 24B at a different position from the position at
which the coupling pin 21 pressed up from below pushes the roller
15 24B. Because of this, two disconnecting-position detecting
1imitswitches22Bareprovidedtoseparatelydetectthecoupling
pin 21 moving from above to below and from below to above in
order to control the stop position of the coupling pin 21 to
be the same in both directions.
20 Although the timing of pressing the closing-position
detecting limit switch 22A, disconnecting-position detecting
limit switch 22B, and earthing-position detecting limit switch
22C varies depending on the lateral positional relationship
between the coupling pin 21 and those limit switches, the
25 U-shaped guide hardware 23 can improve the positioning accuracy
15
between the coupling pin 21 and the closing-position detecting
limit switch 22A, disconnecting-position detecting limit
switch 228, and earthing-position detecting limit switch 22C.
As described above, the switchgear according to this
5 embodiment can improve stopping accuracy at three positions,
i.e., a closing position, a disconnecting position, and an
earthingposition, therebystabilizinginsulationperformance.
The present invention should not be limited to the above
embodiment, but includes various modifications. For example,
10 the above embodiment is detailed descriptions for
comprehensively explaining the present invention, and the
invention should not necessarily be limited to include all the
configurations described above. Furthermore, a part of a
configuration in one embodiment can be replaced by a
15 configuration in another embodiment, and a configuration ln
one embodiment can be added to a configuration in another
embodiment. A part of a configuration in each embodiment can
also be added to, deleted from, or replaced by another
configuration.
20
[Reference Signs List]
1: vacuum insulated switchgear; 2: mold switch; 3:
operating device; 4: operating-force transmission unit; 5:
vacuum interrupter; 6: air-insulated earthing disconnecting
25 switch; 7: first fixed electrode; 8: second fixed electrode;
16
9: third fixed electrode; 10: busbar mold bushing; 11: fixed
electrode; 12: movable electrode; 13 flexible conductor; 14:
movable conductor; 15: bellows; 16: mold bushing; 17: voltage
detector; 18: arc shield; 19: fixed conductor; 20: vacuum
5 chamber; 21: coupling pin; 22A: closing-position detecting
limit switch; 22B: disconnecting-position detecting limit
switch; 22C: earthing-position detecting limit switch; 23:
guide hardware; 23A: first slotted hole; 24A, 24B, 24C: roller;
25: motor; 25A: motor's rotating shaft; 26: operating
10 instrument; 27: solid insulator; 33: feeder conductor; 43: air
movable electrode; 50: main lever; 51, 61: three-phase levers;
51A, 61A: shaft; 52, 62: air-insulated operation rod; 53, 63:
operation rod; 55: operating-instrument-side rod; 61B:
extended shaft; 61C: second slotted hole; 65A: first chain;
15 65B second chain; 66A: first gear; and 66B: second gear.

CLAIMS
1. A switchgear comprising:
an air-insulated earthing disconnecting switch that has
a movable electrode moving linearly and is switchable among
5 a closing position, a disconnecting position, and an earthing
position;
a vacuum interrupter that is electrically connected to
the air-insulated earthing disconnecting switch and makes and
breaks current flow in a vacuum chamber maintained under vacuum;
10 and
15
an operating device of the air-insulated earthing
disconnecting switch, which has a motor and provides driving
force to the movable electrode of the air-insulated earthing
disconnecting switch;
an operating device of the vacuum interrupter, which
provides driving force to a movable electrode of the vacuum
interrupter; and
an operating-force transmission unit that transmits
driving force from the motor of the operating device of the
20 air-insulated earthing disconnecting switch to the movable
25
electrode of the air-insulated earthing disconnecting switch,
wherein the air-insulated earthing disconnecting switch
and the vacuum interrupter are integrally covered with a solid
insulator, and
the operating-force transmission unit includes
18
an operation rod fixedly coupled to the movable
electrode of the air-insulated earthing disconnecting switch,
a shaft rotatably driven by the motor,
a lever fixed to the shaft and making an arc motion
5 with the shaft rotatably driven,
a coupling pin coupling the lever and the operation
rod, and
limit switches that detect that the air-insulated
earthing disconnecting switch is in the closing position,
10 disconnecting position, or earthing position by means of the
coupling pin driven by the operation rod operating with an arc
motion of the lever.
15
2 . The switchgear according to claim 1,
wherein the limit switches are arranged on a U-shaped
guide hardware, the U-shaped guide hardware being disposed so
as to surround the coupling part where the lever and the operation
rod are coupled with the coupling pin and having first slotted
holes extending in the vertical direction in side walls opposite
20 to each other, and
the coupling pin moving in the first slotted holes in
the vertical direction makes contact with the limit switches
arranged at positions corresponding to the closing position,
disconnecting position, and earthing position of the
25 air-insulated earthing disconnecting switch to detect that the
5
19
air-insulated earthing disconnecting switch is in the closing
position, disconnecting position, or earthing position.
3. The switchgear according to claim 2,
wherein the lever has an end with a second slotted hole
extending in the longitudinal direction of the lever,
the coupling pin moves in the second slotted hole in
synchronization with an arc motion of the lever, and
the coupling pin moving in the vertical direction in the
10 first slotted holes causes the operation rod to move in the
vertical direction.
4. The switchgear according to claim 2 or 3,
wherein the limit switches include one limit switch
15 disposed at a position corresponding to the closing position
of the air-insulated earthing disconnecting switch, one limit
switch disposed at a position corresponding to the earthing
position of the air-insulated earthing disconnecting switch,
and two limit switches disposed at positions corresponding to
20 the disconnecting position of the air-insulated earthing
disconnecting switch,
rollers are disposed in the vicinity of the first slotted
holes where the limit switches are disposed at positions
corresponding to the closing, disconnecting, and earthing
25 positions of the air-insulated earthing disconnecting switch,
5
20
and
the coupling pin makes contact with the rollers that press
in the limit switches at the respective positions.
5. The switchgear according to claim 4,
wherein the limit switch disposed corresponding to the
closing position of the air-insulated earthing disconnecting
switch is arranged in an upper part of the U-shaped guide hardware,
the limit switches disposed corresponding to the disconnecting
10 position of the air-insulated earthing disconnecting switch
are arranged in middle parts of the U-shaped guide hardware,
and the limit switch disposed corresponding to the earthing
position of the air-insulated earthing disconnecting switch
is arranged in a lower part of the U-shaped guide hardware.
15
6. The switchgear according to any one of claims 1 to 5,
wherein the air-insulated earthing disconnecting switch
includes a bushing-side fixed electrode connected to a busbar
side conductor, an intermediate fixed electrode connected to
20 the vacuum interrupter, an earth-side fixed electrode that is
at the ground potential, and a movable electrode that makes
contact with the respective fixed electrodes, and
each of the fixed electrodes is arrange linearly ln the
air-insulated earthing disconnecting switch, the movable
25 electrode enters a closed state electrically continued to the
21
busbar side conductor when making contact with the bushing-side
fixed electrode, the movable electrode enters a disconnected
state when the movable electrode is in a position where the
distance between the movable electrode and the bushing-side
5 fixed electrode is greater than the distance between the movable
electrode and the earth-side fixed electrode, and the movable
electrode is at the ground potential when making contact with
the earth-side fixed electrode.