FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
POWER SUPPLY DEVICE AND CAPACITOR;
MITSUBISHI ELECTRIC CORPORATION, A CORPORATION ORGANISED AND
EXISTING UNDER THE LAWS OF JAPAN, WHOSE ADDRESS IS 7-3,
MARUNOUCHI 2-CHOME, CHIYODA-KU, TOKYO 1008310, JAPAN
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE
INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED
2
DESCRIPTION
Technical Field
[0001] The present disclosure relates to a power supply device and a capacitor for
5 reducing electromagnetic noise.
Background Art
[0002] Electric vehicles such as electric railway vehicles and electric cars may
include a power supply device that converts power supplied from a power source to
intended alternating current (AC) power, and supplies the resulting power to a load in the
10 vehicle. An example of such a power supply device is described in Patent Literature 1.
This power supply device includes multiple power modules each including two switching
elements connected in series, and two diodes connected to the respective switching
elements in parallel. When the switching element is switched between on and off, the
power supply device converts power supplied from a battery to AC power to be supplied
15 to a motor, and supplies the resulting power to the motor. To reduce noise caused when
the switching element is switched between on and off, the power supply device also
includes multiple capacitors connected to secondary terminals of the corresponding
power modules.
Citation List
20 Patent Literature
[0003] Patent Literature 1: Unexamined Japanese Patent Application Publication
No. 2017-112789
Summary of Invention
Technical Problem
25 [0004] Each capacitor includes a capacitor element including a dielectric and two
electrodes opposing each other with the dielectric in between, a case that accommodates
the capacitor element, and multiple lead wires each having one end connected to a
3
corresponding one of the electrodes and drawn out of the case. The lead wire connected
to one of the electrodes of the capacitor is connected to the power module through a
busbar and an electric wire. Specifically, the electric wire has one end connected to the
busbar connected to the secondary terminal of the power module, and the other end
5 connected to the lead wire connected to one of the electrodes of the capacitor. The lead
wire connected to the other one of the electrodes of the capacitor is connected to a frame
receiving a reference potential through the electric wire.
[0005] As described above, the capacitor has one of the electrodes electrically
connected to the secondary terminal of the power module through the lead wire, the
10 electric wire, and the busbar, and the other one of the electrodes electrically connected to
the frame through the lead wire and the electric wire. In this structure, an increase in
length of the electric wire and the lead wire increases parasitic inductance and parasitic
impedance. The capacitor may thus fail to sufficiently filter noise, which may result in
failing to provide an intended output wave form.
15 [0006] In response to the above issue, an objective of the present disclosure is to
provide a power supply device with high noise-filtering performance.
Solution to Problem
[0007] To achieve the above objective, a power supply device according to an
aspect of the present disclosure is a power supply device for converting power supplied
20 from a power source to power to be supplied to a load and supplying the converted power
to the load from an output terminal. The power supply device includes a power
converter, a capacitor, a busbar, and an electrically conductive support. The power
converter converts the power supplied from the power source to the power to be supplied
to the load and outputs the converted power to the output terminal. The capacitor
25 includes a dielectric, two electrodes opposing each other with the dielectric in between, a
case, a first terminal, and a second terminal. The capacitor is located in a circuit
between the power converter and the output terminal. The case accommodates the
4
dielectric and the two electrodes. The first terminal is electrically connected to one of
the two electrodes and exposed outside the case. The second terminal is electrically
connected to the other one of the two electrodes and exposed outside the case. The first
terminal is fixed to the busbar. The busbar electrically connects the first terminal to the
5 output terminal. The second terminal is fixed to the electrically conductive support.
The electrically conductive support receives a reference potential.
Advantageous Effects of Invention
[0008] The first terminal of the capacitor included in the power supply device
according to the present disclosure is fixed to the busbar, and electrically connected to the
10 output terminal of the power supply device with the busbar. The second terminal of the
capacitor is fixed to the electrically conductive support that receives a reference potential.
This structure thus does not necessarily include lead wires and electric wires drawn out of
a case to electrically connect the first terminal and the busbar. This structure does not
necessarily include lead wires and electric wires drawn out of a case to electrically
15 connect the second terminal and the support. This structure reduces parasitic inductance
and parasitic impedance resulting from the lead wires and the electric wires, which results
in that the power supply device can have high noise-filtering performance.
Brief Description of Drawings
[0009] FIG. 1 is a block diagram of a power supply device according to
20 Embodiment 1 of the present disclosure;
FIG. 2 is a perspective view of a capacitor according to Embodiment 1;
FIG. 3 is a front view of the capacitor according to Embodiment 1;
FIG. 4 is a cross-sectional view of the capacitor according to Embodiment 1;
FIG. 5 is a drawing of a capacitor element according to Embodiment 1;
25 FIG. 6 is a front view of a capacitor and a frame earth according to Embodiment 2
of the present disclosure;
FIG. 7 is a front view of the capacitor and the frame earth according to
5
Embodiment 2;
FIG. 8 is a front view of a capacitor and a frame earth according to Embodiment 3
of the present disclosure;
FIG. 9 is a front view of the capacitor and the frame earth according to
5 Embodiment 3; and
FIG. 10 is a block diagram of a power supply device according to a modification
of any of the embodiments of the present disclosure.
Description of Embodiments
[0010] A capacitor and a power supply device according to one or more
10 embodiments of the present disclosure is described in detail with reference to the
drawings. In the drawings, the same or equivalent components are given the same
reference numerals.
[0011] Embodiment 1
In Embodiment 1, a power supply device installed in an electric railway vehicle
15 using a direct-current (DC) feeder is described. As illustrated in FIG. 1, a current
collector 3 installed in the electric railway vehicle acquires DC power from a substation,
serving as a DC power source, through an overhead line 2, and supplies the power to a
power supply device 1 according to Embodiment 1. To supply power to a load 4
installed in the electric railway vehicle, the power supply device 1 converts the DC power
20 supplied from the current collector 3 to three-phase alternating-current (AC) power.
The power supply device 1 then supplies the three-phase AC power to the load 4 from
output terminals 1a. Each output terminal 1a is electrically connected to the
corresponding input terminal of the load 4.
[0012] The power supply device 1 includes a contactor MC1 having one end
25 connected to the current collector 3, a filter reactor FL1 having one end connected to the
other end of the contactor MC1, a filter capacitor FC1 having one end connected to the
other end of the filter reactor FL1 and the other end grounded, a power converter 11
6
having primary terminals between which the filter capacitor FC1 is connected, and a
transformer 12 having primary terminals connected to the corresponding secondary
terminals of the power converter 11. The power supply device 1 also includes
capacitors 13 in a circuit between the power converter 11 and the output terminals 1a to
5 reduce noise contained in outputs from the power converter 11. More specifically, the
power supply device 1 includes multiple capacitors 13 each having one end connected to
the corresponding secondary terminal of the transformer 12, and having the other end
grounded. In Embodiment 1, the power supply device 1 includes three capacitors 13.
The power supply device 1 also includes a contactor controller 14 for controlling the
10 contactor MC1, and a switching controller 15 for controlling a switching element
included in the power converter 11.
[0013] The contactor MC1 includes a DC electromagnetic contactor. The
contactor MC1 is controlled by the contactor controller 14. When the contactor
controller 14 turns on the contactor MC1, the one end and the other end of the contactor
15 MC1 are connected to each other. The current collector 3 and the filter reactor FL1 are
thus electrically connected to each other. Consequently, the power converter 11 is
electrically connected to the current collector 3. When the contactor controller 14 opens
the contactor MC1, the one end and the other end of the contactor MC1 are insulated
from each other. The filter reactor FL1 is thus electrically disconnected from the current
20 collector 3. Consequently, the power converter 11 is electrically disconnected from the
current collector 3.
[0014] The filter reactor FL1 reduces harmonic components contained in the
current input from the current collector 3.
The filter capacitor FC1 is charged with DC power supplied from the current
25 collector 3. The filter capacitor FC1 smooths the voltage.
The filter reactor FL1 and the filter capacitor FC1 form an LC filter to reduce noise
components contained in the current input from the overhead line 2.
7
[0015] The power converter 11 converts the DC power supplied from the current
collector 3 through the primary terminals to three-phase AC power. The power
converter 11 then supplies the three-phase AC power to the load 4 through the
transformer 12 connected to the secondary terminals of the power converter 11 and
5 through the capacitors 13. More specifically, when the switching element included in
the power converter 11 is controlled by the switching controller 15, the power converter
11 converts the DC power to three-phase AC power, and supplies the three-phase AC
power to the load 4.
The power converter 11 includes, for example, a constant voltage constant
10 frequency (CVCF) inverter.
[0016] The primary terminals of the transformer 12 are connected to the respective
secondary terminals of the power converter 11. The secondary terminals of the
transformer 12 are connected to the load 4 through the output terminals 1a. The
transformer 12 decreases the voltage of the three-phase AC power input through the
15 primary terminals, and supplies the three-phase AC power with the decreased voltage to
the load 4 from the secondary terminals. The transformer 12 decreases the voltage of
the input three-phase AC power to a voltage appropriate for driving the load 4.
Each capacitor 13 is connected to the corresponding one of the secondary terminals
of the transformer 12, and reduces noise contained in the output from the power converter
20 11.
[0017] The contactor controller 14 acquires a voltage value between the one end of
the contactor MC1 and the other end of the filter capacitor FC1 from a voltage measuring
device (not illustrated) that measures voltage values. When acquiring a voltage value
higher than or equal to a threshold voltage from the voltage measuring device, the
25 contactor controller 14 turns on the contactor MC1. The threshold voltage is set to, for
example, the lower limit of the possible range of the voltage values of the overhead line
2.
8
[0018] After the contactor MC1 is turned on, the switching controller 15 controls
the switching element to maintain the three-phase AC power output by the power
converter 11 at a constant voltage and a constant frequency.
[0019] The above power supply device 1 includes the three capacitors 13 to reduce
5 noise contained in the outputs from the power converter 11. One end of each capacitor
13 is connected to the corresponding secondary terminal of the transformer 12, and the
other end of each capacitor 13 receives a reference potential. More specifically, as
illustrated in FIG. 2, one end of each capacitor 13 is connected to a busbar 21. The
busbar 21 is located in a circuit between the secondary terminals of the transformer 12
10 and the output terminals 1a. The secondary terminals of the transformer 12 are
electrically connected to the load 4 through the busbars 21 and the output terminals 1a.
The other end of each capacitor 13 is connected to a support 23 that receives a reference
potential. The capacitors 13 have the same structure and operate similarly. Thus, the
structure of one of the capacitors 13 is described in detail.
15 [0020] As illustrated in FIGS. 2 to 4, the capacitor 13 includes a case 13c
accommodating a capacitor element 16 (described later), a first terminal 13a exposed
through the case 13c, a second terminal 13b exposed through the case 13c, the capacitor
element 16, a lead tab 17a that electrically connects the capacitor element 16 to the first
terminal 13a, and a lead tab 17b that electrically connects the capacitor element 16 to the
20 second terminal 13b.
[0021] The case 13c has a shape of a cylinder having two closed end surfaces.
The case 13c is insulated from the first and second terminals 13a and 13b. More
specifically, the case 13c includes a hollow cylindrical member formed of aluminum, and
insulators that close two ends of the hollow cylindrical member. The two end surfaces
25 of the case 13c have through-holes to allow the first and second terminals 13a and 13b to
extend through.
[0022] The first terminal 13a is exposed outside through the through-hole in one of
9
the end surfaces of the case 13c. The first terminal 13a, in contact with the busbar 21, is
fixed to the busbar 21. More specifically, the first terminal 13a, in contact with the
busbar 21, is fixed to the busbar 21 with a fastener 22. The fastener 22 is formed of a
conductor, for example, metal such as copper or aluminum. The first terminal 13a, in
5 contact with the busbar 21 and fixed to the busbar 21, is electrically connected to the
busbar 21. The fastener 22 formed of a conductor helps conduction of electricity
between the first terminal 13a and the busbar 21. This structure increases the efficiency
of electrical conduction between the first terminal 13a and the busbar 21.
[0023] In some embodiments, the first terminal 13a may have an insertion hole in
10 which the fastener 22 is fitted. In this case, the fastener 22 may preferably have a screw
shape, and the insertion hole in the first terminal 13a may preferably have a groove in
which the fastener 22 is fitted. The first terminal 13a, in contact with the busbar 21, is
fixed to the busbar 21 with the fastener 22 received in the insertion hole in the first
terminal 13a. The first terminal 13a including a screw terminal is fixed to the busbar 21
15 to resist vibrations from the electric railway vehicle. This reduces the likelihood that the
first terminal 13a is detached from the busbar 21 under vibrations from the electric
railway vehicle.
[0024] In some embodiments, the busbar 21 may be shaped to have the first
terminal 13a fitted with the busbar 21. For example, the busbar 21 may have a recess in
20 which the first terminal 13a is fitted. In this case, the fastener 22 fixes the first terminal
13a to the busbar 21 with the first terminal 13a fitted in the recess in the busbar 21.
Thus, the first terminal 13a is fixed to the busbar 21 to resist vibrations from the electric
railway vehicle. This reduces the likelihood that the first terminal 13a is detached from
the busbar 21 under vibrations from the electric railway vehicle.
25 [0025] The second terminal 13b is exposed outside through the through-hole in the
other one of the end surfaces of the case 13c. The second terminal 13b receives a
reference potential. More specifically, the second terminal 13b, in contact with the
10
support 23 receiving a reference potential, is fixed to the support 23 with a fastener 24.
The support 23 and the fastener 24 are formed of a conductor, such as copper or
aluminum. The second terminal 13b, in contact with the support 23, is fixed to the
support 23 and receives a reference potential. In the example of Embodiment 1, the
5 support 23 is grounded, and the second terminal 13b is grounded. The fastener 24
formed of a conductor helps conduction of electricity between the second terminal 13b
and the support 23. This structure increases the efficiency of electrical conduction
between the second terminal 13b and the support 23.
[0026] In some embodiments, the second terminal 13b may include a screw
10 terminal. In this case, the second terminal 13b, in contact with the support 23, is fixed to
the support 23 with the fastener 24 received in the threaded hole in the second terminal
13b. The second terminal 13b including a screw terminal is fixed to the support 23 to
resist vibrations from the electric railway vehicle. This reduces the likelihood that the
second terminal 13b is detached from the support 23 under vibrations from the electric
15 railway vehicle.
[0027] In some embodiments, the support 23 may have a recess in which the
second terminal 13b is fitted. In this case, the fastener 24 fixes the second terminal 13b
to the support 23 with the second terminal 13b fitted in the recess in the support 23.
Thus, the second terminal 13b is fixed to the support 23 to resist vibrations from the
20 electric railway vehicle. This reduces the likelihood that the second terminal 13b is
detached from the support 23 under vibrations from the electric railway vehicle.
[0028] As illustrated in FIG. 5, the capacitor element 16 includes an electrode 16a,
an electrode 16b, a separator 16c held between the electrodes 16a and 16b, and separators
16d that hold the electrodes 16a and 16b in between. An oxide film formed on the
25 surface of the electrode 16a that is in contact with the separator 16c functions as a
dielectric.
The lead tab 17a electrically connects the electrode 16a to the first terminal 13a.
11
The lead tab 17b electrically connects the electrode 16b to the second terminal 13b.
[0029] In the power supply device 1 according to the embodiment of the present
disclosure, as described above, the first terminal 13a of the capacitor 13 in contact with
the busbar 21 is fixed to the busbar 21, and the second terminal 13b of the capacitor 13 in
5 contact with the support 23 is fixed to the support 23. In other words, the power supply
device 1 does not necessarily use lead wires or electric wires to place the capacitor 13
into contact with the busbar 21 and the support 23. Compared with a known capacitor
including electrodes each connected to a busbar and a frame through a lead wire and an
electric wire, this structure reduces parasitic inductance and parasitic impedance resulting
10 from the lead wires or electric wires, and thus improves the noise filtering performance of
the capacitor 13.
[0030] When an electric wire is used to connect the capacitor to the busbar,
parasitic inductance and parasitic impedance vary depending on the manner of cutting the
electric wire. Depending on the manner of cutting the electric wire, the parasitic
15 inductance and the parasitic impedance may increase, and the noise filtering performance
of the capacitor may be insufficient. In contrast, the power supply device 1 according to
Embodiment 1 does not use an electric wire to connect the capacitor 13 to the busbar 21,
and thus reduces fluctuations in parasitic inductance and parasitic impedance. The
power converter 11 can thus provide an intended output voltage.
20 [0031] In addition, the first terminal 13a adjacent to the output terminal 1a, or in
other words, the shorter length of the busbar 21 from each first terminal 13a to the
corresponding output terminal 1a can reduce the parasitic inductance and the parasitic
impedance resulting from the busbar 21. In some embodiments, the busbar 21 may
preferably have a length of, for example, less than or equal to 300 millimeters from each
25 first terminal 13a to the corresponding output terminal 1a.
[0032] Embodiment 2
Different capacitors 13 are provided to filter noise output from different power
12
converters 11. The capacitors 13 appropriate for filtering noise from different power
converters 11 can have different capacitances. The capacitors 13 with different
capacitances have different dimensions. In the example in Embodiment 1, for the
capacitors 13 with different dimensions, the power supply device 1 is to include the
5 busbar 21 or the support 23 having a different shape. This complicates the assembly of
the power supply device 1 to install the capacitor 13 with appropriate capacitance in
accordance with the measurement results of output voltages from the power converter 11.
In Embodiment 2, a power supply device 1 including a support 25 is described. The
position of the support 25 in contact with the second terminal 13b of the capacitor 13 is
10 adjustable.
[0033] As illustrated in FIG. 6, the capacitor 13 included in the power supply
device 1 according to Embodiment 2 is fixed to the support 25 instead of the support 23.
The power supply device 1 includes a housing 40 that accommodates the capacitor 13.
The housing 40 receives a reference potential. The power supply device 1 according to
15 Embodiment 2 is described using the housing 40 grounded as an example.
The support 25 includes an electrically conductive fixing member 26 fixed to the
grounded housing 40, and an electrically conductive movable member 27 that is movable
relative to the fixing member 26 and in contact with the fixing member 26. The fixing
member 26 and the movable member 27 are formed of a conductor, for example, metal
20 such as copper or aluminum.
The power supply device 1 includes a fastener 28 that fixes the movable member
27 to the fixing member 26, and a fastener 41 that fixes the fixing member 26 to the
housing 40. The fasteners 28 and 41 are formed of a conductor, for example, metal such
as copper or aluminum. The fastener 28 formed of a conductor helps conduction of
25 electricity between the movable member 27 and the fixing member 26. This structure
increases the efficiency of electrical conduction between the movable member 27 and the
fixing member 26. The fastener 41 formed of the conductor helps conduction of
13
electricity between the fixing member 26 and the housing 40. This structure increases
the efficiency of electrical conduction between the fixing member 26 and the housing 40.
[0034] The fixing member 26 has a surface facing the movable member 27 and a
surface facing the housing 40. The surface of the fixing member 26 facing the movable
5 member 27 has multiple through-holes 26a. The surface of the fixing member 26 facing
the housing 40 has a through-hole 26b.
The movable member 27 has a surface facing the second terminal 13b of the
capacitor 13 and a surface facing the fixing member 26. The surface of the movable
member 27 facing the fixing member 26 has a through-hole 27a.
10 The surface of the housing 40 facing the fixing member 26 has an insertion hole
40a.
The fastener 28 extends through the through-hole 26a and 27a to fix the movable
member 27 to the fixing member 26.
The fastener 41 extends through the through-hole 26b, and is received in the
15 insertion hole 40a to fix the fixing member 26 to the housing 40.
[0035] As illustrated in FIG. 7, in accordance with the dimensions of the capacitor
13, the movable member 27 may be moved relative to the fixing member 26, and the
fastener 28 may be inserted into the through-hole 27a and a through-hole 26a different
from the through-hole 26a in FIG. 6 to fix the movable member 27 to the fixing member
20 26.
[0036] As described above, the power supply device 1 according to Embodiment 2
can adjust the position of the support 25 to be in contact with the second terminal 13b in
accordance with the dimensions of the capacitor 13. Thus, the shape of the busbar 21
and the support 25 is not necessarily changed in accordance with the dimensions of the
25 capacitor 13. This simplifies the assembly of the power supply device 1.
[0037] Embodiment 3
A withstanding voltage test may be conducted to determine whether the power
14
converter 11 has dielectric strength sufficient for the working voltage. When a
withstanding voltage test is conducted with the second terminal 13b of the capacitor 13
grounded, the capacitor 13 receives a high voltage and may be broken. To avoid this, a
power supply device 1 according to Embodiment 3 includes a mechanism for
5 disconnecting the second terminal 13b of the capacitor 13 from the support that receives a
reference potential. The power supply device 1 according to Embodiment 3 is
described.
[0038] As illustrated in FIG. 8, the capacitor 13 included in the power supply
device 1 according to Embodiment 3 is fixed to a support 29 instead of the support 25.
10 The support 29 includes an electrically conductive reference member 30 fixed to
the housing 40 that receives a reference potential, an electrically conductive mount
member 31 to which the second terminal 13b of the capacitor 13 in contact with the
mount member 31 is fixed, and a switch mechanism 32 that electrically connects the
mount member 31 to the reference member 30 or electrically disconnects the mount
15 member 31 from the reference member 30 with a mechanical operation. In
Embodiment 3, the housing 40 is grounded. The reference member 30, the mount
member 31, and the switch mechanism 32 are formed of a conductor, for example, metal
such as copper or aluminum.
[0039] The power supply device 1 also includes a fastener 35 that fixes the mount
20 member 31 to the reference member 30. The power supply device 1 also includes a
fastener 42 that fixes the reference member 30 to the housing 40, an insulating member
43 that comes into contact with the mount member 31 and the housing 40, and a fastener
44 that fixes the mount member 31 to the housing 40. The fastener 42 is formed of a
conductor, for example, metal such as copper or aluminum. The fastener 42 formed of a
25 conductor helps conduction of electricity between the reference member 30 and the
housing 40. This structure increases the efficiency of electrical conduction between the
reference member 30 and the housing 40. The fastener 44 is formed of an insulator,
15
such as resin or ceramics.
[0040] The reference member 30 has a surface facing the mount member 31 and a
surface facing the housing 40. The surface of the reference member 30 facing the
housing 40 has a through-hole 30a.
5 The mount member 31 has a surface facing the second terminal 13b and a surface
facing the housing 40. The surface of the mount member 31 facing the housing 40 has a
through-hole 31a.
The switch mechanism 32 includes a shaft 33 fixed to the mount member 31, and a
rotator 34 attached to the shaft 33 and rotatable about the shaft 33. The shaft 33 and the
10 rotator 34 included in the switch mechanism 32 are formed of a conductor, for example,
metal such as copper or aluminum.
[0041] The surface of the housing 40 facing the reference member 30 has an
insertion hole 40b. The surface of the housing 40 facing the mount member 31 has an
insertion hole 40c.
15 The insulating member 43 is held between the mount member 31 and the housing
40. The insulating member 43 is formed of an insulator such as resin or ceramics.
Thus, the insulating member 43 electrically disconnects the mount member 31 from the
housing 40. The insulating member 43 has a through-hole 43a. The through-hole 43a
extends in the direction in which the mount member 31 and the housing 40 face each
20 other.
[0042] The fastener 35 fixes the rotator 34 in contact with the reference member 30
to the reference member 30. When the rotator 34 is fixed to the reference member 30,
the mount member 31 and the reference member 30 are electrically connected to each
other. Thus, the second terminal 13b in contact with the mount member 31 and fixed to
25 the mount member 31 is grounded.
The fastener 42 extends through the through-hole 30a to be received in the
insertion hole 40b to fix the reference member 30 to the housing 40.
16
The fastener 44 extends through the through-holes 31a and 43a to be received in
the insertion hole 40c to fix the mount member 31 to the housing 40 with the insulating
member 43 held between the mount member 31 and the housing 40.
[0043] As illustrated in FIG. 9, when the rotator 34 rotates about the shaft 33 in a
5 direction away from the reference member 30, the rotator 34 and the reference member
30 are separated from each other. Thus, the mount member 31 is electrically
disconnected from the reference member 30. Consequently the second terminal 13b of
the capacitor 13 is disconnected from the reference member 30 that receives a reference
potential. Separating the rotator 34 and the reference member 30 from each other
10 prevents the capacitor 13 from receiving a high voltage when a withstanding voltage test
is conducted on the power converter 11.
[0044] As described above, in the power supply device 1 according to Embodiment
3, the switch mechanism 32 electrically connects the mount member 31 to the reference
member 30 or electrically disconnects the mount member 31 from the reference member
15 30 with a mechanical operation of the rotator 34 rotating about the shaft 33.
[0045] Embodiments of the present disclosure are not limited to the above
examples.
For example, the power supply device 1 may have any circuit structure that
performs power conversion. For example, the power supply device 1 may include a
20 power converter including a DC-to-DC converter. The power supply device 1
illustrated in FIG. 10 includes a power converter 18 including a DC-to-DC converter,
instead of the power converter 11. One end of each capacitor 13 is connected to the
corresponding one of the secondary terminals of the power converter 18.
[0046] The mode of fixing the first terminal 13a to the busbar 21 and the mode of
25 fixing the second terminal 13b to the support 23, 25, or 29 are not limited to the above
examples.
For example, the first terminal 13a may include a flange at the end that comes into
17
contact with the busbar 21. Similarly, the second terminal 13b may include a flange at
the end that comes into contact with the support 23, 25, or 29.
In another example, the busbar 21 may include a protrusion to be fitted in the
insertion hole in the first terminal 13a. In this case, the protrusion of the busbar 21 has a
5 through-hole that allows the fastener 22 to extend through. This through-hole may
preferably have a groove in which the screw-shaped fastener 22 is fitted. Similarly, the
support 23, 25, or 29 may include a protrusion to be fitted in the insertion hole in the
second terminal 13b. In this case, the protrusion of the support 23, 25, or 29 has a
through-hole that allows the fastener 24 to extend through. This through-hole may
10 preferably have a groove in which the screw-shaped fastener 24 is fitted.
[0047] The first terminal 13a may be arranged without being directly in contact
with the busbar 21 as described above. For example, the first terminal 13a may be fixed
to the busbar 21 with a first conductive member held between the first terminal 13a and
the busbar 21. The first conductive member includes, for example, an elastic conductive
15 ring. Similarly, the second terminal 13b may be fixed to the support 23, 25, or 29 with a
second conductive member held between the second terminal 13b and the support 23, 25,
or 29.
[0048] To increase the efficiency of electrical conduction between the busbar 21
and the first terminal 13a, the contact surfaces between the first terminal 13a and the
20 busbar 21 may preferably be mirror-finished. Similarly, the contact surfaces between
the second terminal 13b and the support 23, 25, or 29 may preferably be mirror-finished.
Alternatively, to increase the efficiency of electrical conduction between the
busbar 21 and the first terminal 13a, the power supply device 1 may also include an
electrically conductive compound applied to the contact surfaces between the first
25 terminal 13a and the busbar 21. Similarly, the power supply device 1 may also include
an electrically conductive compound applied to the contact surfaces between the second
terminal 13b and the support 23, 25, or 29.
18
[0049] The power supply device 1 may also include an electrically conductive
adhesive applied to the surroundings of the first terminal 13a fixed to the busbar 21.
The method for fixing the first terminal 13a to the busbar 21 is not limited to the
above-described examples and includes, for example, soldering and welding. Similarly,
5 the method for fixing the second terminal 13b to the support 23, 25, or 29 is not limited to
the above-described examples and includes, for example, soldering and welding.
[0050] The shapes of the first and second terminals 13a and 13b are not limited to
the above examples. For example, the first and second terminals 13a and 13b may be
tapered or may have a smaller thickness toward the distal end.
10 For example, the first and second terminals 13a and 13b may have a plate shape.
In this case, the distal end of the first terminal 13a may be bent and come into contact
with the busbar 21. In addition, the fastener 22 may extend through the through-hole
formed in the distal end of the first terminal 13a to fix the first terminal 13a to the busbar
21. Similarly, the distal end of the second terminal 13b may be bent and come into
15 contact with the support 23, 25, or 29. In addition, the fastener 24 may extend through
the through-hole formed in the distal end of the second terminal 13b to fix the second
terminal 13b to the support 23, 25, or 29.
[0051] The fixing member 26 and the movable member 27 may have any shape
and structure that allow the movable member 27 to move relative to the fixing member
20 26. For example, the movable member 27 may slide along a groove formed on the
fixing member 26.
[0052] The switch mechanism 32 may have any shape that enables electrical
connection between the mount member 31 and the reference member 30 and electrical
disconnection of the mount member 31 from the reference member 30 with a mechanical
25 operation. For example, the switch mechanism 32 may include a knife switch.
[0053] The power supply device 1 is also installable in an electric railway vehicle
using an AC feeder. In this case, the power supply device 1 also includes a converter
19
that converts AC power to DC power.
[0054] The foregoing describes some example embodiments for explanatory
purposes. Although the foregoing discussion has presented specific embodiments,
persons skilled in the art will recognize that changes may be made in form and detail
5 without departing from the broader spirit and scope of the invention. Accordingly, the
specification and drawings are to be regarded in an illustrative rather than a restrictive
sense. This detailed description, therefore, is not to be taken in a limiting sense, and the
scope of the invention is defined only by the included claims, along with the full range of
equivalents to which such claims are entitled.
10 Reference Signs List
[0055]
1 Power supply device
1a Output terminal
2 Overhead line
15 3 Current collector
4 Load
11, 18 Power converter
12 Transformer
13 Capacitor
20 13a First terminal
13b Second terminal
13c Case
14 Contactor controller
15 Switching controller
25 16 Capacitor element
16a, 16b Electrode
16c, 16d Separator
20
17a, 17b Lead tab
21 Busbar
22, 24, 28, 35, 41, 42, 44 Fastener
23, 25, 29 Support
5 26 Fixing member
26a, 26b, 27a, 30a, 31a, 43a Through-hole
27 Movable member
30 Reference member
31 Mount member
10 32 Switch mechanism
33 Shaft
34 Rotator
40 Housing
40a, 40b, 40c Insertion hole
15 43 Insulating member
FC1 Filter capacitor
FL1 Filter reactor
MC1 Contactor
21
We Claim:
1. A power supply device for converting power supplied from a power source
to power to be supplied to a load and supplying the converted power to the load from an
output terminal, the power supply device comprising:
5 a power converter to convert the power supplied from the power source to the
power to be supplied to the load and to output the converted power to the output terminal;
a capacitor including a dielectric, two electrodes opposing each other with the
dielectric in between, a case accommodating the dielectric and the two electrodes, a first
terminal electrically connected to one of the two electrodes and exposed outside the case,
10 and a second terminal electrically connected to the other one of the two electrodes and
exposed outside the case, the capacitor being located in a circuit between the power
converter and the output terminal;
a busbar to which the first terminal is fixed, the busbar electrically connecting the
first terminal to the output terminal; and
15 an electrically conductive support to which the second terminal is fixed, the
electrically conductive support being configured to receive a reference potential.
2. The power supply device according to claim 1, wherein
the case has a shape of a cylinder having two closed end surfaces,
20 the first terminal is exposed outside the case through one of the end surfaces, and
the second terminal is exposed outside the case through the other one of the end
surfaces.
3. The power supply device according to claim 1 or 2, wherein the first
25 terminal is adjacent to the output terminal.
4. The power supply device according to claim 3, wherein the busbar has a
22
length of less than or equal to 300 millimeters from the first terminal to the output
terminal.
5. The power supply device according to any one of claims 1 to 4, wherein the
5 first terminal is fixed to the busbar with the first terminal being in contact with the busbar.
6. The power supply device according to any one of claims 1 to 4, wherein the
first terminal is fixed to the busbar with a first conductive member held between the first
terminal and the busbar.
10
7. The power supply device according to any one of claims 1 to 6, wherein the
second terminal is fixed to the support with the second terminal being in contact with the
support.
15 8. The power supply device according to any one of claims 1 to 6, wherein the
second terminal is fixed to the support with a second conductive member held between
the second terminal and the support.
9. The power supply device according to any one of claims 1 to 8, further
20 comprising:
a housing accommodating the capacitor,
wherein
the support includes
an electrically conductive fixing member fixed to the housing and
25 configured to receive the reference potential, and
an electrically conductive movable member movable relative to the fixing
member and in contact with the fixing member, and
23
the second terminal is fixed to the movable member with the second terminal being
in contact with the movable member.
10. The power supply device according to any one of claims 1 to 9, wherein the
5 support includes
an electrically conductive reference member to receive the reference potential,
an electrically conductive mount member in contact with the second terminal, and
a switch mechanism to electrically connect the mount member to the reference
member or electrically disconnect the mount member from the reference member with a
10 mechanical operation.
11. The power supply device according to any one of claims 1 to 10, wherein
the capacitor is a plurality of the capacitors,
the busbar is a plurality of the busbars, and
15 the first terminal of each of the plurality of capacitors is fixed to a corresponding
busbar of the plurality of busbars, and each of the plurality of busbars electrically
connects the first terminal to a corresponding output terminal of a plurality of the output
terminals.
20 12. A capacitor for a power supply device for converting power supplied from a
power source to power to be supplied to a load and supplying the converted power to the
load from an output terminal, the capacitor comprising:
a dielectric;
two electrodes opposing each other with the dielectric in between;
25 a case accommodating the dielectric and the two electrodes;
a first terminal electrically connected to one of the two electrodes and exposed
outside the case; and
24
a second terminal electrically connected to the other one of the two electrodes and
exposed outside the case,
wherein
the first terminal is fixed to a busbar connected to the output terminal, and the
5 busbar electrically connects the first terminal to the output terminal, and
the second terminal is fixed to an electrically conductive support and is configured
to receive a reference potential.