Technical Field
[0001]
The present invention relates to a switch, more
specifically relates to a switch including a plurality of
10 switching units disposed in series.
Background Art
[0002]
A rapid-transit railway such as the Shinkansen adopts
15 an AC electrification system to secure large power. Since
power is supplied from individual substations, a section is
provided to isolate a neighbor power source. Such a
configuration is specifically illustrated in Fig. 11. An
dead section 100 is disposed at an appropriate place in
20 order to isolate the power supplies GI and G2 from each
other. The dead section 100 has a length set to about 1 km.
When a train 101 passes through the dead section 100, a
section switch VS1 is first closed to charge the dead
section 100. While the train 101 passes through the dead
25 section 100, the section switch VS1 is opened and the
s e c t i o n switch VS2 i s c l o s e d , s o t h a t a charge source for
t h e dead s e c t i o n 100 is changed from G1 t o G 2 . Discharged
time during t h i s o p e r a t i o n is c o n t r o l l e d t o about 0.05 t o
0.3 s e c , so t h a t t h e t r a i n 101 can pass through t h e dead
5 s e c t i o n 100 s t i l l a t high speed without c o a s t i n g . When t h e
t r a i n 101 has passed through t h e dead s e c t i o n 1 0 0 , t h e
s e c t i o n switch VS2 is opened.
Examples of e x i s t i n g switches i n c l u d e a switch
described i n Patent L i t e r a t u r e 1 t h a t is however d i f f e r e n t
10 from t h e above-described switch f o r t h e r a p i d - t r a n s i t
r a i l w a y . P a t e n t L i t e r a t u r e 1 d e s c r i b e s a DC breaker f o r DC
c u r r e n t breaking i n which a p l u r a l i t y of e n e r g i z i n g vacuum
b r e a k e r s and breaking vacuum breakers disposed i n p a r a l l e l
t o t h e e n e r g i z i n g vacuum breakers a r e provided between a DC
15 power supply and a r e a c t o r a s a load, and t h e breaking
vacuum b r e a k e r s a r e disposed i n p a r a l l e l t o one another. In
Patent L i t e r a t u r e 1, t h e e n e r g i z i n g vacuum breakers a r e
provided s e p a r a t e l y from t h e breaking vacuum b r e a k e r s .
During e n e r g i z a t i o n , t h e breaking vacuum breakers a r e opened,
20 while t h e e n e r g i z i n g vacuum breakers a r e c l o s e d . On the
o t h e r hand, during braking, t h e breaking vacuum breakers a r e
f i r s t c l o s e d , and then t h e e n e r g i z i n g vacuum breakers a r e
opened t o cornmutate a c u r r e n t t o each breaking vacuum
b r e a k e r , and then t h e breaking vacuum breakers disposed i n
25 s e r i e s a r e s e q u e n t i a l l y opened, so t h a t t h e DC c u r r e n t is
finally decreased to zero through attenuation according to a
predetermined time constant gi-ven by a series circuit of
resistances provided in parallel to the breaking vacuum
breakers and the reactor.
Citation List
Patent Literature
[0003]
Patent Literature 1: Japanese Patent Application Laid-
10 Open No. H05-81973
Summary of Invention
Technical Problem
15 When the above-described operating method is applied
to the section switches VS1 and VS2, the following problem
occurs. The section switch VS2 is closed during passing of
the train 101 to make a load current. When the section
switch VS2 is opened, the train 101 has passed through the
20 dead section 100, and the section switch VS2 is opened at no
load. If the load current is repeatedly made, a contact
surface in the switch is roughened due to pre-arc. If the
load current is broken, the electrode surface is smoothed by
arc generated during the breaking. In the case of the
25 section switch VS2, however, since load making and no-load
breaking are repeated, the contact surface is gradually
roughened, leading to a possibility of lowering of
withstanding voltage. If interelectrode breakdown occurs in
the section switch VS2, short circuit occurs between the
5 power supplies G1 and G2, which leads to a serious accident
that may disturb train service. Patent Literature 1
basically does not consider such roughening of the contact
surface.
An object of the invention is therefore to provide a
10 reliable switch having a contact surface that is prevented
from being roughened.
Solution to Problem
[0005]
15 To solve the above-described problem, according to the
invention, there is provided a switch including a plurality
of switching units each including a fixed electrode and a
movable electrode that is disposed to be opposed to the
fixed electrod-e and is closed or opened with respect to the
20 fixed electrode, the switch being characterized in that the
switching units each make or break a current to be applied
to the switch, the switching units are electrically
connected in series to each other, and the switching units
are configured such that a first switching unit is first
25 closed, and then a second switching unit is closed.
Advantageous Effects of Invention
[0006]
According to the present invention, it is possible to
5 provide a reliable switch havinq a contact surface that is
prevented from being roughened.
Brief Description of Drawings
[0007]
10 Figure 1 is a rear view of a switch according to
Embodiment 1.
Figure 2 is a sectional side view of the switch
according to Embodiment 1. 6
Figure 3 is an overall structural diagram of an
15 operational unit of the switch according to Embodiment 1.
Figure 4 is a sectional view of an electromagnet of
the operational unit of the switch according to Embodiment 1.
Figure 5 is a diagram of a control circuit for driving
two electromagnets in the switch accordjng to Embodiment 1.
Figure 6 is a schematic illustration of operation
timings of two vacuum interrupters in the switch according
to Embodiment 1.
Figure 7 is a rear view of a switch according to
Embodiment 2.
Figure 8 is an overa3.l structural diagram of an
operational unit of the switch according to Embodiment 2.
Figure 9 is a diagram illustrating stroke
characteristics in closing of the switch according to
5 Embodiment 2,
Figure 10 is a sectional side view of a switch
according to Embodiment 3.
Figure 11 is a diagram for explaining a role of a
section switch.
10
Description of Embodiments
[0008]
Hereinafter, some preferred embodiments of the present
invention will be described with reference to the
15 accompanying drawings. The following description merely
shows example embodiments, and the subject matter of the
invention is not limited to the following specific modes.
It will be appreciated that the invention can also be
modified or altered into various modes in addition to the
20 following modes.
Embodiment 1
[0009]
A switch according to Embodiment 1 is now described
25 with reference to Figures 1 to 6. As illustrated in Figures
1 and 2, a switch 1 includes vacuum interrupters 2 and 3
each having a vacuum inside, and operational units each
including an electromagnet (in Embodiment 1, the vacuum
interrupter 2 and a breaking vacuum interrupter 2, or the
5 vacuum interrupter 3 and a disconnecting vacuum interrupter
3 are assumed to be equivalent to each other).
The vacuum interrupters 2 and 3 internally accommodate
electrode pairs 4 and 5 each including a fixed electrode and
a movable electrode that is disposed to be opposed to the
10 fixed electrode and is closed or opened with respect to the
fixed electrode. Each of the electrode pairs 4 and 5 is
opened or closed (is into a contact or separate state) while
the vacuum state is maintained, thereby the circuit is
allowed to be made or broken. The breaking vacuum
15 interrupter 2 has a current breaking function, and the
disconnecting vacuum interrupter 3 has an anti-surge
function. Conductors 6 and 7 for connection to a power
supply or a load are fixed to upper sides of the vacuum
interrupters 3 and 3, respectively. Movable conductors 8
20 and 9 are provided on the lower sides of the vacuum
interrupters 2 and 3 while being connected to movable-side
electrodes and disposed to penetrate through the vacuum
interrupters 2 and 3, respectively. The movable conductors
8 and 9 extend to the respective outsides of the vacuum
25 interrupters and are electrically connected to current
col.lectors 10 and 11, respectively. The current collectors
10 and 11 are fixed to conductors 12 and 13, respectively,
and are connected to each other by a connecting conductor 14.
Specifically, the breaking vacuum interrupter 2 and the
5 disconnecting vacuum interrupter 3 are connected in series
via the connection conductor 14. The movable conductor 8 is
connected to an insulative operating rod 46 that is
connected to a wipe spring 42 to be connected to the
insulative operating rod 46 and a shaft 40. The movable
10 conductor 9 is connected to an insulative operatinq rod 47
that is connected to a wipe spring 43 to be connected to the
insulative operating rod 47 and a shaft 41. The shaft 41 is
connected to an electromagnet 22.
The breaking vacuum interrupter 2 and the disconnecting
15 vacuum interrupter 3 are peripherally covered with
insulators 15 and 16, respectively, and are fixed to a
housing 17 on an electromagnet side with the respective
insulators 15 and 16 in between, so that electrical
j.solat.j.ng performance under high voltage is secured.
20 An operating unit for the breaking vacuum interrupter 2 and
the disconnecting vacuum interrupter 3 is now described.
The breaking vacuum interrupter 2 and the disconnecting
vacuum interrupter 3 are connected to electromagnets 21 and
22, respectively. As illustrated in Figure 3, the housing
25 17 internally accommodates the electromagnets 22 on its
1-ower side, and accommodates capacitors 50 and 53 and a
control circuit board 52 on its upper side ori/above a
support plate 48 located above the electromagnets 22. The
capacitors 50 and 51 are connected in parallel to the
5 control circuit board 52, and are connected to the
electromagnets 21 and 22, respectively, via the control
circuit board 52. A breaking spring 44 is disposed on a
lower side of the electromagnet 21, and the breaking spring
44 is compressed or released depending on a position of a
10 non-magnetic material rod 34 described later. A breaking
spring 45 is also disposed on a lower side of the
electromagnet 22, and the breaking spring 45 is compressed
or released depending a position of a non-magnetic material
, rod 34 provided in the electromagnet 22.
15 Figure 4 illustrates a section of the electromagnet 21 or 22.
In Embodiment 1, the same electromagnet is used for the
electromagnets 21 and 22 that therefore have the same
configuration; hence, the electromagnets 21 and 22 are
collectively described. The electromagnet 21 or 22 is
20 configured of a stack of a lower iron plate 23, a
cylindrical steel pipe 24 that is provided above the lower
iron plate 23 while being in contact with a peripheral end
of the lower iron plate 23 and is disposed so as to cover
the periphery of a coil 29 described later, a permanent
25 magnet base 25 disposed above the steel pipe 24 and the coil
29 whi1.e being in contact with the upper side of the steel
pipe 24, a cylindrical steel pipe 26 provided above a
peripheral end of the permanent magnet base 25, and an upper
iron plate 27 that is provided on the steel pipe 26 so as to
5 act as a lid-like member for the steel pipe 26. The
electromagnet 21 or 22 internally accommodates a coil 29
disposed on an inner side of the steel pipe 24, a central
leg 28 that is disposed on an inner side of the coil 29 and
on the lower iron plate 23, a T-shaped movable iron core 31
10 disposed on the central leg 28, and a permanent magnet 30
disposed on the permanent magnet base 25. The T-shaped
movable iron core 31 is configured of a plunger 32 disposed
above the central leg 28, and a movable flat plate 33
disposed above the plunger 32. The permanent magnet 30 is
15 vertically sandwiched by the movable flat plate 33 and the
permanent magnet base 25. A rod 34 made of a nonmagnetic
material such as stainless steel vertically runs through the
center of each of the movable iron core 31 and the central
leg 28. The rod 34 is connected to the shaft 40 or 41 in
20 the outside on the lower side of the electromagnet 21 or 22.
Figure 4 illustrates a state of the electromagnet 21 or 22
while the contact pair is made. Magnetic flux generated by
the permanent magnet 30 flows along a path including, in
sequence, the permanent magnet 30, the movable flat plate 33,
25 the plunger 32, the central leg 28, the lower iron plate 23,
the steel plpe 24, the perrridnent magnet base 25, and the
permanent magnet 30, and causes attractive force between the
plunger 32 and the central leg 28, and between the movable
tlat plate 33 and the permanent magnet 30. Fj-gure 4 shows a
5 closed state of the electromagnet 21 or 22, in which the
wipe spring 42 or 43 (illustrated in Figure 1) for providing
contact force to the electrode and the breaking spring 44 or
45 (illustrated in Figure 3) for opening the electromagnet
21 or 22 are compressed. The closed state is maintained by
10 the attractive force of the permanent magnet 30.
To describe the operation of the electromagnet 21 or 22,
when the electromagnet 21 or 22 is closed, the coil 29 is
excited such that magnetic flux is generated in the same
direction as that of the magnetic flux generated by the
15 permanent magnet 30. When the electromagnet 21 or 22 is
opened, the coil 29 is excited in a direction opposite to
that in closing to cancel the magnetic flux generated by the
permanent magnet 30, so that the electromagnet 21 or 22 is
allowed to operate by the force of the wipe spring 43 or 43
20 and the force of the breaking spring 44 or 45.
The coil 29 is excited using power stored in the capacitor
50 or 51. Figure 5 illustrates a circuit configuration of
the control circuit board 52. The capacitors 50 and 51 are
connected in parallel to a charging circuit 61 via diodes 66
25 so as to be allowed to be discharged independently of each
other. The capacitors 50 and 51 are connected to the coils
29 via respective circuits 62 and 63 for changing the
exciting direction between the closing and the opening.
Main switches 54 and 65 are provided between the capacitors
5 50 and 51 and the circuits 62 and 63, respectively. When
the main switch 64 is closed, the capacitor 51, the circuit
62, and the coil 29 of the electromagnet 21 form a closed
circuit, and discharge of the capacitor 51 is started, but
the capacitor 50 is not discharged since the diode 66 is
10 provided. Conversely, when the main switch 65 is closed,
the capacitor 50, the circuit 63, and the coil 29 of the
electromagnet 22 form a closed circuit, and discharge of the
capacitor 50 is started, but the capacitor 51 is not
discharged since the diode 66 is provided. In this way, the
15 main switches 64 and 65 are changeably switched, and
therethrough it is possible to control timing at which the
power stored in each capacitor is discharged to the coil 29
of each of the electromagnets 21 and 22, i.e., opening-andclosing
timing of each of the brea-king va-cuum interrupter 2
20 and the disconnecting vacuum interrupter 3.
Specifically, the timing is set as illustrated in Figure 6.
In making (ON), the disconnecting vacuum interrupter 3 is
first made (closed), and then the breaking vacuum
interrupter 2 is made. Since the contact pairs in the two
25 vacuum interrupters are connected in series, the power
supply is effectively connected to the load at making of the
breaking vacuum interrupter 2 that 1s made second. In
breaking (OFF), the breaking vacuum interrupter 2 first
starts opening operation, and then the disconnecting vacuum
5 interrupter 3 starts opening operation.
Effects of the invention are now described. A vacuum switch
is typically used for the section switches VS1 and VS2
illustrated in Figure 11. In the case of the abovedescribed
operating method, since the section switch VS2 is
10 repeatedly subjected to load making and no-load breaking,
the contact surface of the section switch VS2 is gradually
roughened, leading to a possibility of lowering of
withstanding voltage. In contrast, according to the switch
1 according to Embodiment 1, the disconnecting vacuum
15 interrupter 3 is made or broken at no load in each case, and
thus roughening of the contact surface limitedly occurs in
the breaking vacuum interrupter 2, and initial electrical
isolating performance of the disconnecting vacuum
interrupter 3 can be maintained. As described in Japanese
20 Patent Application No. 2012-059632, the electrode pair of
the breaking vacuum interrupter 2 can be improved in
breaking performance by disposing an Ag-W-C material as a
low-surge material in a contact surface. More preferably, a
portion to be roughened of the contact surface is beforehand
25 specified (collected), and the material, which allows the
contact surface to be less roughened, is disposed in that
portion. The interelectrode breakdown in the section switch
leads to a serious accident that causes short-circuit
between different power supplies; hence, it is significant
5 that isolating reliability is improved by the switch
described in Embodiment 1. The roughening of the contact
surface is particularly greatly affected by load making.
Hence, opening operation may not be necessarily performed at
such timings that the disconnector is first opened and then
10 the breaker is opened, and operation timing may be shifted
only in closing operation.
To avoid pre-arc of the disconnecting vacuum
interrupter 3 in closing operation, operation time is
desirably shifted by 10 ms or more to sufficiently secure an
15 gap distance of the breaking vacuum interrupter 2 connected
in series to the disconnecting vacuum interrupter 3. The
reason for setting the shift time to 10 ms or more is as
follows: a half cycle of 50 Hz passes within such a period
at least one time, and thus at least one voltage peak exists
20 in the period. To generalize this, operation time should be
shifted by at least a half cycle of an AC frequency, i.e.,
by at least (1x10~/)( ~xx)[m s] with respect to a power
supply of an AC frequency X [Hz]. In breaking operation,
assuming that arc is iginiting during one cycle in breaking,
25 the disconnecting vacuum interrupter 3 is desirably opened
by 20 ms or more later than the breaking vacuum interrupter
2. The reason for setting the delay to 20 ms or more is as
follows: one cycle of 50 Hz passes within such a period at
least one time, and thus at least two current zero point
5 exists in the period, and consequently the AC current can be
broken. To generalize this, operation time should be
shifted by at least one cycle of an AC frequency, i.e., by
at least ( 1 x 1 0 ~ )/ X [ms] with respect to a power supply of an
AC frequency X [Hz].
10 Although Embodiment 1 has been described with a case where
the electromagnets 21 and 22 are used in the operating unit,
it is obvious that the electromagnets do not exclusively
perform one or both of (1) making (closing) operation where
the disconnecting vacuum interrupter 3 is made (closed)
15 prior to the breaking vacuum interrupter 2 and subsequently
the breaking vacuum interrupter 2 is made, and (2) opening
operation where the disconnecting vacuum interrupter 3 first
starts opening and then the breaking vacuum interrupter 2
starts openj~ng, and an electric motor charged spring
20 operating unit or pneumatic operating unit is also allowed
to provide similar effects.
According to Embodiment 1, a plurality of switching units
are electrically connected in series to each other, and the
switching units are configured such that the disconnecting
25 vacuum interrupter 3 as a first switching unit is first
closed, and then the breaking vacuum interrupter 2 as a
second switching unit is closed; hence, since one vacuum
interrupter (the disconnecting vacuum interrupter 3 in the
above-described operation) is closed at no load in each case,
5 a reliable switch having a contact surface being prevented
from being roughened can be provided without degrading
electrical isolating performance.
Embodiment 2
10 [OOlO]
Embodiment 2 is now described with reference to
Figures 7 to 9. In Embodiment 2, the breaking vacuum
interrupter 2 and the disconnecting vacuum interrupter 3 are
driven with a common shaft 60 and a common electromagnet 61.
15 A single capacitor 70 is provided in accordance with the
single electromagnet 61. While not shown, the single
capacitor 70 allows the circuit configuration of the control
circuit board 52 to be accordingly changed from the dual
circuit into a single circuit including one d.iod.e a.nd one
20 main switch. The single electromagnet is disposed at the
center of the housing 17 to avoid tilt of the shaft 60.
Other configurations are similar to those in Embodiment 1,
and duplicated description is omitted. Figure 9 illustrates
stroke characteristics in closing. In a switch 55 of
25 Embodiment 2, the stroke length of the electromagnet 61
(accurately, a value converted into a moved distance on a
vacuum interrupter side with a relative ratio of length of a
lever of the shaft 60 from a rotation axis) SMAG is equal to
the sum of an gap distance S1 of the vacuum interrupter 2
5 and wipe length W1, and to the sum of an gap distance S2 of
the vacuum interrupter 3 and wipe length W2.
In other words, when the gap distance (a distance between
the movable electrode and the fixed electrode of the
switching unit) of the disconnecting vacuum interrupter 3 in
10 the opened state is set shorter than the gap distance of the
breaking vacuum interrupter 2 in the opened state, the
disconnecting vacuum interrupter 3 is first made, so that
effects similar to those described in Embodiment 1 can be
exhibited.
15 According to Embodiment 2, the number of components such as
the electromagnets and the capacitors can be decreased, and
the control circuit can be simplified, and consequently the
switch can be achieved in a simple configuration.
20 Embodiment 3
[OOll]
Embodiment 3 is now described with reference to Figure
10. In Embodiment 3, the switch described in Embodiment 2
is modified such that the breaking vacuum interrupter 2 and
25 the disconnecting vacuum interrupter 3 are arranged in a
verti-cal dj-rection to reduce footprint. Although Figure 10
looks similar to Figure 2 in Embodiment 1 at the first
glance, when the switch is viewed in a front or back
direction, only one electromagnet 70 is provided, and the
5 breaking vacuum interrupter 2 and the disconnecting vacuum
interrupter 3 occupy area corresponding to one vacuum
interrupter in a horizontal direction (since the two vacuum
interrupters are stacked in a vertical direction); hence,
the occupied area is actually about half the area of the
10 vacuum interrupters in Figure 2.
In this case, vertical power of a rod 75, which is driven in
a vertical direction, is converted into horizontal power.
Hence, an operating-unit-side link unit 72 is connected to
the rod 75, and a shaft 71 that moves in a horizontal
15 direction is connected to the operating-unit-side link unit
72. In addition, a switching-unit-side link unit 74, which
is vertically branched across the shaft 71, is provided on a
vacuum interrupter side of the shaft 71. Each of ends of
the switching-unit side link u.nit 74, the end being opposite
20 to an end close to the shaft 71, is connected to each of the
movable conductors of the two vacuum interrupters.
The power transmission mechanism such as the link unit is
not limited to the mode described herein. When a plurality
of switching units are disposed in a vertical direction, and
25 if each switching unit can be operated at one of the abovedescrjbed
timings, the footprint can be reduced whi-le the
effects described in Embodiments 1 and 2 are provided.
As a possible measure for achieving such a timing,
specifically, the gap distance of the disconnecting vacuum
5 interrupter 3 in the opened state is set shorter than the
gap distance of the breaking vacuum interrupter 2 in the
opened state, thereby the disconnecting vacuum interrupter 3
is first closed, so that effects similar to those in
Embodiment 1 can be provided.
10 It will be appreciated that the electromagnet may not be
necessarily provided in the operating unit not only in
Embodiment 1 but also in each of Embodiments 2 and 3.
Moreover, although the vacuum interrupter is used in the
switching unit in each of Embodiments, the vacuum
15 interrupter may not be exclusively used. Using the vacuum
interrupter allows the switch to be small and reliable.
Reference Signs List
[0012]
l...switch
2...breaking vacuum interrupter
3...disconnecting vacuum interrupter
21, 22 . . . electromagnet
41.. .shaft
42, 43 . . . wipe spring
44, 45. . .breaking spring
50, 51 . . . capacitor
52 . . . control circuit board
64, 65...main switch
SMAG . . . stroke of electromagnet
S1, S2 . . . gap distance of vacuum interrupter
W1, W2 ... wipe length

WE CLAIMS:-
A switch including a plurality of switching units each
5 including a fixed electrode and a movable electrode that is
disposed to be opposed to the fixed electrode and is closed
or opened with respect to the fixed electrode,
wherein the switching units each make or break a
current to be applied to the switch,
10 the switching units are electrically connected in
series to each other, and
the switching units are configured such that a first
switching unit is first closed, and then a second switching
unit is closed.
Claim 2
The switch according to claim 1, wherein the switching
units are configured such that the second switching unit
first starts opening operation, and then the first switching
20 unit starts opening operation.
Claim 3
The switch according to claim 2, wherein the switching
units are configured such that the second switching unit
25 first starts opening operation, and after the lapse of time
of at least one cycle of an AC frequency applied to the
switch, the first switching unit starts opening operation.
Claim 4
The switch according to any one of claims 1 to 3
further including an operating unit configured to operate
the movable electrodes,
wherein the switching units are allowed to operate by
driving force generated by the operating unit in such a
10 manner that
the first switching unit is first closed, and then the
second switching unit is closed, or
the second switching unit first starts opening
operation, and then the first switching unit starts opening
15 operation.
Claim 5
The switch according to claim 4,
wherein. t h e operating unit has electromagnets t h a . t
20 generate driving force for operating the movable electrodes,
the movable electrodes of the switching units are
allowed to move by the driving force generated by the
electromagnets,
the operating unit further includes movers provided in
25 the electromagnets, and
capacitors that are charged with electric power and
allow the movers to be operated through discharge of the
power,
the electromagnets are provided for the individual
5 switchinq units, and a switch is provided between each of
the electromagnets and each of the capacitors,
the switch provided between the electromagnet that
generates driving force for operating the movable electrode
of the first switching unit and the capacitor is first
10 closed, and then the switch provided between the
electromagnet that generates driving force for operating the
movable electrode of the second switching unit and the
capacitor is closed, thereby the first switching unit is
first closed, and then the second switching unit is closed,
15 or
the switch provided between the electromagnet that
generates driving force for operating the movable electrode
of the second switching unit and the capacitor is first
closed, and then the switch provided between the
20 electromagnet that generates driving force for operating the
movable electrode of the first switching unit and the
capacitor is closed, thereby the second switching unit first
starts opening operation, and then the first switching unit
starts opening operation.
25
Claim 6
The switch according to claim 4,
wherein the operating unit is provided as a single
unit, and has a movable section configured to transmit
5 operating force to a side of the movable electrodes,
the switch further includes a first spring and a
second spring that each expand and contract along with
movement of the movable section,
the first spring transmits driving force from the
10 operating unit to the movable electrode of the first
switching unit,
the second spring transmits driving force from the
operating unit to the movable electrode of the second
switching unit, and
15 a distance between the movable electrode and the fixed
electrode of the first switching unit in an opened state is
smaller than a distance between the movable electrode and
the fixed electrode of the second switching unit in an
opened state.
Claim 7
The switch according to claim 6, wherein the first
switching unit and the second switching unit are arranged in
a vertical direction.
Claim 8
The switch according to any one of claims 1 to 7,
wherein the first switching unit is first closed, and after
the lapse of time of at least a half cycle of an AC
5 frequency applied to the switch, the second switching unit
is closed.
Claim 9
The switch according to any one of claims 1 to 8,
10 wherein the first switching unit is a disconnecting
unit having an anti-surge function, and
the second switching unit is a breaking unit having a
current breaking function.
15 Claim 10
The switch according to any one of claims 1 to 9,
wherein each of the switching units accommodates the fixed
electrode and the movable electrode within a vacuum
interrupter having a vacuum inside.