TITLE OF INVENTION
ELECTRIC POWER CONVERSION DEVICE
FIELD OF THE INVENTION
5 The present invention relates to an electric power
conversion device composed of semiconductor switching
devices.
BACKGROUND OF THE INVENTION
10 In the variable speed drive, a system using an
electric power conversion device, that is, a system of
converting an alternating current from a commercial
power source to a direct current by a diode rectifier
circuit or a PWM converter and furthermore driving a
15 motor at a variable frequency via an inverter from
smoothed DC power is general.
When a load to be driven becomes a large capacity
and the voltage cannot be increased, it is necessary to
increase the current and raise the capacity of the
20 conversion device and in such a case, a plurality of
semiconductor switching devices composing the electric
power conversion device (here, an IGBT will be
explained as an example) are often used in a parallel
connection state. In the conversion device using
25 semiconductor switching devices, it is a problem to
- 2 -
''**' reduce the wire inductance to suppress the voltage
increase during switching and when the semiconductor
switching devices are connected in parallel, suppress
the imbalance of the partial charge of current.
5 On the.other hand, in patent literatures (PTLs) 1
and 2, the aforementioned problem is solved by
laminating the conductor plate connected to the
positive pole of the first semiconductor module and the
conductor plate connected to the negative pole of the
10 second semiconductor module to form opposing portions
and by laminating the conductor plate connected to the
negative pole of the first semiconductor module and the
conductor plate connected to the positive pole of the
second semiconductor module to form opposing portions.
15 In PTL 2, as a snubber circuit for suppressing the
voltage increase of the semiconductor switching device,
the so-called RCD snubber circuit composed of a series
body of a snubber capacitor and a snubber diode and a
discharge resistor for discharging the snubber
20 capacitor is supposed. Therefore, due to the time lag
of switching of the parallel connected IGBT, even if a
difference appears in the voltage of the snubber
capacitor between the parallel circuits, a reverse
current is prevented by the snubber diode, so that no
25 oscillating current is generated.
- 3 -
*''"^ The aforementioned RCD snubber circuit requires a
diode and a resistor, thus the conversion device can be
hardly miniaturized, so that there is a system of
connecting only a capacitor to both terminals of the
5 switching, device (called a clamp, .capacitor) . . ..
PRIOR TECHNICAL DOCUMENT
PATENT DOCUMENT
PATENT DOCUMENT 1: Japanese Patent Laid-Open
10 Publication No. 2007-151286
PATENT DOCUMENT 2: Japanese Patent Laid-Open
Publication No. 2010-98846
SUMMARY OF THE INVENTION
15 When the aforementioned clamp capacitors are used,
the clamp capacitors are connected in parallel by the
wire conductor plates, so that an LC circuit of a
minute resistance is formed and when a difference
appears in the capacitor voltage, there are
20 possibilities that an oscillating current may be
generated. If the inductance of the circuit between the
parallel connected clamp capacitors is high, the
oscillating current when a voltage difference appears
between the clamp capacitors cannot be suppressed, so
25 that the inductance of this circuit needs to be reduced.
- 4 -
'''*' In the PATENT DOCUMENTS 1 and 2, the inductance of
the circuit formed between the clamp capacitors is not
considered and the reduction of the inductance is
insufficient.
5 , The problem to be solved by the present invention . .,
is to reduce the wire inductance of the circuit formed
between the terminals of the semiconductor switching
devices connected in parallel in the electric power
conversion device.
10 To solve the aforementioned problem, the present
invention, in an aspect thereof, is an electric power
conversion device formed by parallel-connecting a
plurality of semiconductor modules with two
semiconductor switching devices connected in series
15 between the DC terminals, that is, an electric power
conversion device including the first semiconductor
module and second semiconductor module which are
connected in parallel between the DC terminals, the
first conductor plate connected to the first terminal
20 of the first semiconductor module, the second conductor
plate connected to the first terminal of the second
semiconductor module, and the third conductor plate
connected to the second terminals of the first and
second semiconductor modules and having a structure
25 that the first to third conductor plates are laminated
- 5 -
*'**' to form opposing portions, wherein the first connection
terminal for electrically connecting the first
conductor plate to the second conductor plate and the
second connection terminal for electrically connecting
5 the second conductor plate to the first conductor plate
are arranged so as to be brought closer to each other
than the distance between any terminals of the first to
third conductor plates.
The present invention, in another aspect, is an
10 electric power conversion device formed by parallelconnecting
a plurality of semiconductor modules with
two semiconductor switching devices connected in series
between the DC terminals, that is, an electric power
conversion device including the first semiconductor
15 module and second semiconductor module which are
connected in parallel between the DC terminals, the
first conductor plate connected to the first terminal
of the first semiconductor module, the second conductor
plate connected to the first terminal of the second
20 semiconductor module, and the third conductor plate
connected to the second terminals of the first and
second semiconductor modules and having a structure
that the first to third conductor plates are laminated
to form opposing portions, wherein the connection
25 terminal of a leading portion to be connected to one of
- 6 -
"^"^ the DC terminals for electrically connecting the first
conductor plate and the second conductor plate is
arranged between two connection terminals which are a
leading portion to be connected to another one of the
5 DC terminals from, the third conductor plate.
According to a preferred aspect of the present
invention, the wire inductance of the circuit formed
between the terminals of the semiconductor switching
devices connected in parallel can be reduced.
10 Therefore, when the clamp capacitors are structured
by directly connecting a capacitor between the
terminals of the first semiconductor module and between
the terminals of the second semiconductor module, the
oscillating current when a voltage difference appears
15 between the parallel connected clamp capacitors can be
suppressed.
The other objects and characteristics of the
present invention will be made clear in the Embodiments
described below.
20
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a perspective view showing the conductor
plate structure of the electric power conversion device
according to Embodiment 1 of the present invention,
25 Fig. 2 is an exploded perspective view of the
- 7 -
**«^ laminated conductor plate of Embodiment 1 of the
present invention,
Fig. 3 is a perspective view showing the comparison
of the conductor plate structure for explanation of the
5 effects of the present invention, . _..
Fig. 4 is a perspective view showing a mounting
structure example of the clamp capacitor of the present
invention,
Fig. 5 is a perspective view showing the conductor
10 plate structure of the electric power conversion device
according to Embodiment 2 of the present invention.
Fig. 6 is an exploded perspective view of the
laminated conductor plate of Embodiment 2 of the
present invention,
15 Fig. 7 is a perspective view showing the conductor
plate structure of the electric power conversion device
according to Embodiment 3 of the present invention.
Fig. 8 is an exploded perspective view of the
laminated conductor plate of Embodiment 3 of the
20 present invention.
Fig. 9 is a perspective view showing the conductor
plate structure of the electric power conversion device
according to Embodiment 4 of the present invention.
Fig. 10 is an exploded perspective view of the
25 laminated conductor plate of Embodiment 4 of the
- 8 -
''^»' present invention,
Fig. 11 is a perspective view showing the conductor
plate structure of the electric power conversion device
according to Embodiment 5 of the present invention,
5 Fig. 12 is a perspective view showing the conductor
plate structure of the electric power conversion device
according to Embodiment 6 of the present invention.
Fig. 13 is a schematic block diagram of the drive
system of the elevator to which the present invention
10 is applied, and
Fig. 14 is a parallel constitution diagram of the
semiconductor modules composing the main circuit of the
elevator shown in Fig. 13.
15 DESCRIPTION OF THE PREFERRED EMBODIMENTS
Fig. 13 is a schematic block diagram of the drive
system of the elevator to which the present invention
is applied.
DC power which is rectified by a converter 1 from a
20 power source (here, a three-phase power source is used)
81 and is smoothed by a smoothing capacitor 3 is
converted to AC power of a variable frequency and a
variable voltage by an inverter 2 and is supplied to a
drive motor 9 of the elevator to drive the elevator.
25 Namely, the motor 9 rotates a rope pulley 91 and drives
a riding cage 92 and a balance weight 93 which are
- 9 -
""^^ hanged by a rope 94 to move up and down.
To reduce the harmonics to the power source and
increase the voltage, between the power source 81 and
the converter 1, a reactor 82 is often connected.
5 Further, in addition to it, a filter circuit is.
generally connected, though it is not related directly
to the present invention, so that it is not shown in
the drawing.
The converter 1 is composed of three-phase legs 11
10 to 13 and in each phase, parallel bodies of a
semiconductor switching device (here, an IGBT is
explained as an example) and a circulation diode
(referred to as FWD) , for example, 1101 and 1102 are
structured as a pair of upper and lower sides. The IGBT
15 and FWD are composed of separate semiconductor chips,
though here, they are codes as one parallel body (for
example, 1101). The inverter 2 is also similarly
composed of three-phase legs 21 to 23.
To realize a large capacity of the electric power
20 conversion device, the semiconductor switching devices
may be connected to each other in parallel..
Fig. 14 is a parallel constitution diagram of the
semiconductor modules composing the main circuit of the
drive system of the elevator to which the present
25 invention is applied.
- 10 -
^»' In the example shown in the drawing, a
semiconductor module 111 having a pair of upper and
lower sides (1111 and 1112) of the IGBT and FWD builtin
and a semiconductor module 112 similarly having 1121
5 and 1122 built-in are connected in parallel. Further,
to the respective semiconductor modules 111 and 112,
clamp capacitors 41 and 42 for suppressing the voltage
increase during switching are connected.
In Fig. 14, to suppress the voltage increase during
10 switching, the inductance of a round circuit LI
composed of a smoothing capacitor and a semiconductor
module which are not drawn needs to be reduced. Further,
for realization of uniformity of the partial charge of
current of the semiconductor modules 111 and 112, the
15 inductances of both modules need to be uniform, which
has been achieved in the constitution of the PATENT
DOCUMENT 1.
On the other hand, as described before, if the
inductance of a circuit L2 between the parallel
20 connected clamp capacitors 41 and 42 is high, the
oscillating current when a voltage difference appears
between the clamp capacitors 41 and 42 cannot be
suppressed. Therefore, the inductance of the circuit L2
needs to be reduced.
25 In the PATENT DOCUMENTS 1 and 2, in the IGBT
- 11 -
^'•»- parallel circuit shown in Fig. 14, regarding the
circuit (the dashed line LI shown in Fig. 14) including
a smoothing capacitor not drawn, the reduction in the
inductance is realized and the inter-parallel
5 inductance is uniformed, though the...inductance of the
circuit (the dotted line L2 shown in Fig. 14) connected
of the clamp capacitors 41 and 42 is not considered and
the oscillating current when a voltage difference
appears between the clamp capacitors 41 and 42 cannot
10 be suppressed.
For example, in the constitution of the conductor
plate of PTL 1 shown in Figs. 11, 12, and 14, the
circuit (the dotted line L2 shown in Fig. 14) between
the parallel clamp capacitors is connected to a
15 conductor plate PC via a conductor plate connection a3
from a connection a2 of a conductor plate CPl from a DC
positive pole terminal PI, is connected to a connection
b3 of a conductor plate CP2 by the conductor plate PC,
and is connected to another clamp capacitor by a
20 connection b2 of the conductor plate CP2. The negative
pole of the capacitor, because terminals c2 and c3 of a
DC negative pole conductor plate N are connected to
each other with the conductor plate N, and the
inductance of this portion is low, though the
25 connections a3 and b3 between the conductor plates CPl
- 12 -
'**«*»' and CP2 are separated from each other, is not suitable
for reduction in the inductance of the circuit (the
dotted line L2 shown in Fig. 14) connected of the clamp
capacitors 41 and 42. Similarly, in the constitution
5 shown in Figs. 23 and 24 of the PATENT DOCUMENT 1, the
portion connected to the conductor plate CPl and the
portion connected to the conductor plate CP2 are
separated from each other, so that the negative pole of
the capacitor is not suitable for reduction in the
10 inductance of the circuit connected of the clamp
capacitors.
Hereinafter, the embodiments of the present
invention for reducing the wire inductance of the
circuit formed between the terminals of the parallel
15 connected semiconductor switching devices will be
explained with reference to the accompanying drawings.
Further, in each drawing and each embodiment, the same
numeral is assigned to each same or similar component
and the explanation therefor will be omitted.
20 {Embodiment 1}
Fig. 1 is a perspective view showing the conductor
plate structure of the electric power conversion device
according to Embodiment 1 of the present invention and
Fig. 2 is an exploded perspective view of the laminated
25 conductor plate thereof.
- 1 3 -
'*'«»' Similarly to the PATENT DOCUMENT 1, an embodiment
that the semiconductor modules 111 and 112 in which the
positive pole PI and a negative pole Nl are arranged in
line on one side are arranged so that the terminals
5 . approach each other and are connected in parallel..is
indicated.
As a conductor plate for wiring, there exist, as a
conductor plate on the positive pole side, a first
conductor plate 51 connected to the DC positive pole
10 terminal PI and a second conductor plate 52 connected
to the DC positive pole terminal P2. As a conductor
plate on the negative pole side, there exist a
conductor plate 53 connected to the DC negative pole
terminal Nl and a DC negative pole terminal N2. These
15 three conductor plates are laminated via an insulated
portion not drawn in the order of 51, 53, and 52 from
this side.
Firstly, the first conductor plate 51 includes a
terminal 511 directly connected to the DC positive pole
20 terminal PI of the semiconductor module 111 and a
terminal 512 to be connected to a terminal 611 of a
conductor plate 61 connected to the positive pole of
the smoothing capacitor 3.
Further, the second conductor plate 52 includes a
25 terminal 521 directly connected to the DC positive pole
- 14 -
N*- terminal P2 of the semiconductor module 112 and a
terminal 522 to be connected to a terminal 612 of the
conductor plate 61 connected to the positive pole of
the smoothing capacitor 3.
5 Furthermore, the third conductor plate .. 5 3 . includes
a terminal 531 directly connected to the DC negative
pole terminal Nl of the semiconductor module 112 and a
terminal 532 directly connected to the DC negative pole
terminal N2 of the semiconductor module 112.
10 The situation of these terminals can be clearly
confirmed by the exploded perspective view of Fig. 2.
Here, the terminal 512 of the first conductor plate
51 to be connected to the terminal 611 of the conductor
plate 61 connected to the positive pole of the
15 smoothing capacitor 3 and the terminal 522 of the
second conductor plate 52 to be connected to the
terminal 612 of the conductor plate 61 connected to the
positive pole of the smoothing capacitor 3 are arranged
in the neighborhood of the center so as to approach
20 each other. Namely, the relationship -between an
interval dl and an interval d2 shown in Fig. 1 is dl <
d2.
The connection of the terminals 512 and 611 and the
connection of the terminals 522 and 612 are all a DC
25 positive pole and on the other hand, the terminals 533
- 15 -
'^•^ and 534 are connected to the DC negative pole via the
conductor plate 62 at different potentials, so that an
insulated distance needs to be secured. Further, the
terminals 512 and 522 are at the same potential, so
5 that,no insulated distance is necessary. Therefore, as .„ .
mentioned above, compared with the interval d2 of the
connections at the different potentials, the interval
dl of the connections at the same potential may be
shorter. Due to the same potential, the interval dl may
10 be zero, though there exist the negative pole conductor
plate 53 and the insulated portion between the
conductor plates, so that the connections at the same
potential do not exist on the same plane. Therefore,
the portion of the conductor plate 61 connected to the
15 terminals 512 and 522 needs to be divided and in
consideration of manufacture errors, a separation of
several millimeters enables easy manufacture.
Fig. 3 is a perspective view showing the comparison
of the conductor plate structure for explanation of the
20 effects of Embodiment 1 of the present invention.
Fig. 3(A) shows Embodiment 1 of the present
invention, and Fig. 3(B) shows a comparison example
with Figs. 12 and 14 of the PATENT DOCUMENT 1 applied
to, and Fig. 3(C) shows a comparison example with Figs.
25 23 and 24 of the PATENT DOCUMENT 1 applied to.
- 1 6 -
'•^•^ The portion with the interval of the positive poles
connected in the circuit L2 between the clamp
capacitors shown in Fig. 14 is shown with a dashed, line.
Further, regarding the connection between the negative
5 poles, in every case, the negative poles are connected .
via the conductor plate 53 on the negative pole side.
In the comparison examples shown in Figs. 3(B) and 3(C),
the terminals 512 and 522 are arranged away from each
other and the area enclosed by the circuit L2 is
10 widened, while in Fig. 3(A), due to approaching of the
terminals 512 and 522, the inductance can be reduced.
As mentioned above, according to Embodiment 1 of
the present invention, due to the reduction in the
inductance between the parallel connected clamp
15 capacitors, the oscillating current can be suppressed.
Further, in the comparison example shown in Fig. 3(C),
the two conductor plates 51 and 52 connected to the
positive pole side are different in shape, while in
Embodiment 1 of the present invention, they can be
20 formed in the same shape.
Further, in Figs. 1 to 3, with respect to the
conductor plates 61 and 62, the positive pole side
conductor plate 61 is arranged above the other, though
even if the negative pole side conductor plate 62 is
25 inversely arranged above the other, the effect will not
- 17 -
''**' be changed. Further, in the examples shown in Figs. 1,
2, and 3(A), the first terminal 512 is arranged on the
lower right side of the drawing, and the second
terminal 522 is arranged on the upper left side of the
5 drawing, though even if the arrangement of both
terminals is inversely interchanged, the area of the
circuit L2 can be reduced and the inductance can be
reduced exactly similarly.
Fig. 4 is a perspective view showing a mounting
10 structure example of the clamp capacitors of the
present invention. A mounting example of the clamp
capacitors 41 and 42 which are omitted in the previous
explanation to easily understand the terminals of the
semiconductor modules and conductor plate shape is
15 shown. The clamp capacitors 41 and 42 are directly
connected to the semiconductor modules 111 and 112 as
shown in the drawing, thus a reduction in the
inductance is realized. Further, in the previous
examples, as shown in Fig. 14, the case that the clamp
20 capacitors 41 and 42 are connected is a prior condition
for the explanation. However, the IGBT itself has an
electrostatic capacity in the off state and when the
switching timing is shifted, there are possibilities of
generation of an oscillating current during that period.
25 To prevent this oscillating current, the inductance
- 18 -
'*•»' needs to be reduced and even when no clamp capacitors
are connected, the present invention is effective.
Embodiment 1 aforementioned is an electric power
conversion device formed by parallel-connecting a
5 plurality of semiconductor modules (111, 112, ) with
two semiconductor switching devices connected in series
between the DC terminals, that is, an electric power
conversion device including the first semiconductor
module (111) and the second semiconductor module (112)
10 which are respectively connected in parallel between
the DC terminals (PI, P2 - Nl, N2), the first conductor
plate (51) connected to the first terminal (PI) of the
first semiconductor module (111), the second conductor
plate (52) connected to the first terminal (P2) of the
15 second semiconductor module (112), and the third
conductor plate (53) connected to the second terminals
(Nl, N2) of the first and second semiconductor modules
(111, 112) and having a structure that the first to
third conductor plates (51 to 53) are laminated to form
20 opposing portions, wherein the first connection
terminal (512) for electrically connecting the first
conductor plate (51) to the second conductor plate (52)
and the second connection terminal (522) for
electrically connecting the second conductor plate (52)
25 to the first conductor plate (51) are arranged so as to
- 19 -
^*^ be brought closer to each other (the interval dl) than
the distance between any terminals of the first to
third conductor plates (51 to 53).
Further, in other words, in an electric power
5 conversion device having a structure that the first to
third conductor plates (51 to 53) are laminated to form
opposing portions, the first conductor plate (51) and
the second conductor plate (52) are connected
electrically and the connection terminal (512 and/or
10 522) which is a leading portion to be connected to one
of the DC terminals is arranged between two connection
terminals (533, 534) which are a leading portion to be
connected to another one of the DC terminals.
{Embodiment 2}
15 Fig. 5 is a perspective view showing the conductor
plate structure of the electric power conversion device
according to Embodiment 2 of the present invention and
Fig. 6 is an exploded perspective view of the laminated
conductor plate thereof. Here, the conductor plates 53
20 and 62 on the negative pole side have the same
structure as that of Embodiment 1 shown in Figs. 1 and
2. The positive pole side has a structure that the
first connection terminal 512 and the second connection
terminal 522 directly make contact with each other and
25 are electrically connected to each other and
- 20 -
^'*«»' furthermore are directly connected to the connection
terminal 611 of the conductor plate 61.
By use of such a constitution, the area enclosed by
the circuit between the clamp capacitors can be reduced
5 much more, so that the effect of the induction
reduction is great.
On the other hand, as shown in Fig. 6, the
conductor plates 51 and 52 on the positive pole side
have the same shape, though the connection needs to be
10 bent and attention needs to be paid to the insulation
security in the neighborhood of the connection.
{Embodiment 3 }
Fig. 7 is a perspective view showing the conductor
plate structure of the electric power conversion device
15 according to Embodiment 3 of the present invention and
Fig. 8 is an exploded perspective view of the laminated
conductor plate thereof.
The respect that the connection terminals 512 and
522 directly make contact with each other and thereby
20 are electrically connected to each other is the same as
that of Embodiment 2. Here, the connection terminal 533
on the negative pole side is not divided to be kept as
one place.
Therefore, one vacant space is sufficient for
25 insulation security of each connection terminal, so
- 21 -
^*^ that the width of the conductor portion of the
connection terminal can be widened. However, the
connection terminal 533 becomes close to the DC
negative pole terminal Nl and becomes remote from
5 another DC negative pole terminal N2, so that there are
possibilities that the current flowing to the smoothing
capacitor 3 via the conductor plate 62 on the negative
pole side may become non-uniform.
This Embodiment 3 is an electric power conversion
10 device formed by parallel-connecting a plurality of
semiconductor modules (111, 112, ) with two
semiconductor switching devices connected in series
between the DC terminals, that is, an electric power
conversion device including the first semiconductor
15 module (111) and the second semiconductor module (112)
which are respectively connected in parallel between
the DC terminals (PI, P2 - Nl, N2), the first conductor
plate (51) connected to the first terminal (PI) of the
first semiconductor module (111), the second conductor
20 plate (52) connected to the first terminal (P2) of the
second semiconductor module (112), and the third
conductor plate (53) connected to the second terminals
(Nl, N2) of the first and second semiconductor modules
(111, 112) and having a structure that the first to
25 third conductor plates (51, 52, 53) are laminated to
- 22 -
*"*»• form opposing portions, wherein the DC first terminals
(512, 522, 611) for electrically connecting the first
conductor plate (51), the second conductor plate (52),
and one of the DC terminals and the DC second terminals
5 (532, 621) connected to another one of the. DC terminals
from the third conductor plate (53) are arranged in
line at intervals in an almost parallel direction to
the plane to which the first to third conductor plates
(51 to 53) are opposite.
10 {Embodiment 4}
Fig. 9 is a perspective view showing the conductor
plate structure of the electric power conversion device
according to Embodiment 4 of the present invention and
Fig. 10 is an exploded perspective view of the
15 laminated conductor plate thereof.
Here, the semiconductor module 11 composing one
phase of the converter 1 shown in Fig. 13 and the
semiconductor module 21 composing one phase of the
inverter 2 are assumed as one unit, and the three units
20 compose three phases, and the unit of one phase in this
case is shown. Further, the semiconductor modules 11
and 21 have a standard structure that the positive pole
terminals PI and P2, the negative pole terminals Nl and
N2, and the AC terminal AC are arranged in a row at the
25 center of the module.
- 23 -
'*•»' The intervals between the positive poles and the
negative poles of the semiconductor modules are
connected in parallel, though the alternating current
is connected separately and the switching operations
5 are not performed simultaneously. .When the clamp
capacitors are connected between the positive poles and
the negative poles, if any of the semiconductor modules
is switched, the voltage of the capacitor connected to
the module is changed, so that between the clamp
10 capacitor and another clamp capacitor, there are
possibilities that an oscillating current may be
generated. To early suppress the oscillating current,
the inductance needs to be reduced. Therefore,
similarly to Embodiment 1, the connection terminals 512
15 and 522 are arranged close to each other.
(Embodiment 5}
Fig. 11 is a perspective view showing the conductor
plate structure of the electric power conversion device
according to Embodiment 5 of the present invention.
20 This Embodiment 5 has a constitution that the four
semiconductor modules 111, 112, 113, and 114 are
connected in parallel. The two-row parallel connection
is the same constitution as that of Embodiment 1 and
the conductor plates 61 and 62 have a structure
25 corresponding to the four-row parallel connection. Also
- 24 -
'*•" in this case, the constitution is such that the
connections 512 and 522 approach each other and there
exists the entirely same constitution in the lower
right portion, so that the inductance can be reduced
5 similarly to the previous Embodiments.
{Embodiment 6}
Fig. 12 is a perspective view showing the conductor
plate structure of the electric power conversion device
according to Embodiment 6 of the present invention.
10 Also in this embodiment, the four semiconductor
modules are connected in parallel, though the positive
pole Pi of the semiconductor module 111 and the
positive pole P3 of the semiconductor module 113 are
connected with the same conductor plate 51. Similarly,
15 though hidden in the drawing, the positive pole P2 of
the semiconductor module 112 and the positive pole P4
of the semiconductor module 114 are connected with the
same conductor plate 52. Further, the negative poles Nl,
N2, N3, and N4 of the four semiconductor modules are
20 connected to the one conductor plate 53. In Fig. 11,
the divided conductor plates are unified, thus the
inductance between the parallel connections can be
reduced more.

w WHAT IS CLAIMED IS:
1. An electric power conversion device formed by
parallel-connecting a plurality of semiconductor
modules with two semiconductor switching devices
5 connected in series between DC terminals, comprising:
a first semiconductor module and a second
semiconductor module which are connected in parallel
between said DC terminals,
a first conductor plate connected to a first
10 terminal of said first semiconductor module,
a second conductor plate connected to a first
terminal of said second semiconductor module, and
a third conductor plate connected to second
terminals of said first and second semiconductor
15 modules, and having:
a structure that said first to third conductor
plates are laminated to form opposing portions,
wherein:
a first connection terminal for electrically
20 connecting said first conductor plate to said second
conductor plate and a second connection terminal for
electrically connecting said second conductor plate to
said first conductor plate are arranged so as to be
brought closer to each other than a distance between
25 any other terminals of said first to third conductor
- 26 -
^/^ plates.
2. An electric power conversion device formed by
parallel-connecting a plurality of semiconductor
modules with two semiconductor switching devices
5 connected in series between DC terminals, comprising:
a first semiconductor module and a second
semiconductor module which are connected in parallel
between said DC terminals,
a first conductor plate connected to a first
10 terminal of said first semiconductor module,
a second conductor plate connected to a first
terminal of said second semiconductor module, and
a third conductor plate connected to second
terminals of said first and second semiconductor
15 modules, and having:
a structure that said first to third conductor
plates are laminated to form opposing portions,
wherein:
a connection terminal of a leading portion to be
20 connected to one of said DC terminals for electrically
connecting said first conductor plate and said second
conductor plate is arranged between two connection
terminals of a leading portion to be connected to
another one of said DC terminals from said third
25 conductor plate.
- 27 -
^^ 3. The electric power conversion device according
to Claim 1 or 2, further comprising a smoothing
capacitor connected between said DC terminals, wherein:
said connection terminal of said leading portion to
5 be connected to one of said DC terminals for
electrically connecting said first conductor plate and
said second conductor plate is connected to a terminal
of a leading conductor plate to one end of said
smoothing capacitor,
10 said third conductor plate includes third and
fourth connection terminals to a leading conductor
plate at another end of said smoothing capacitor,
said first to fourth connection terminals are
arranged in line at intervals on a surface almost
15 parallel to a surface to which said first to third
conductor plates are opposite, and
an interval between said first connection terminal
and said second connection terminal is narrower than an
interval between said connection terminals and said
20 third or fourth connection terminal.
4. The electric power conversion- device according
to Claim 3, wherein:
said interval between said first connection
terminal and said third connection terminal is almost
25 equal to said interval between said second connection
- 28 -
^^ terminal and said fourth connection terminal.
5. The electric power conversion device according
to Claim 1 or 2, wherein:
said first connection terminal and said second
5 connection terminal are overlapped and connected ......
together so as to make direct contact each other.
6. An electric power conversion device according to
Claim 1 or 2, wherein:
said first conductor plate and said second
10 conductor plate are in the same shape.
7. An electric power conversion device formed by
parallel-connecting a plurality of semiconductor
modules with two semiconductor switching devices
connected in series between DC terminals, comprising:
15 a first semiconductor module and a second
semiconductor module which are respectively connected
in parallel between said DC terminals,
a first conductor plate connected to a first
terminal of said first semiconductor module,
20 a second conductor plate connected to a first
terminal of said second semiconductor module, and
a third conductor plate connected to second
terminals of said first and second semiconductor
modules, and having:
25 a structure that said first to third conductor
- 29 -
plates are laminated to form opposing portions,
^^ wherein:
a DC first terminal for electrically connecting
said first conductor plate, said second conductor plate,
,5 and one of said DC terminals, and a DC second terminal
to be connected to another one of said DC terminals
from said third conductor plate are arranged in line at
intervals in an almost parallel direction to a surface
to which said first to third conductor plates are
10 opposite.
8. The electric power conversion device according
to any one of Claims 1, 2, and 7, wherein:
said first and second conductor plates are
connected to positive poles of said DC terminals and
15 said third conductor plate is connected to a negative
pole of said DC terminals.
9. The electric power conversion device according
to any one of Claims 1, 2, and 7, wherein:
a capacitor is connected directly between said
20 terminals of said first semiconductor module andbetween
said terminals of second semiconductor module.
10. The electric power conversion device structured
by combining several ones of Claims 1, 2, and 7.
11. An electric power conversion device, substantially as
herein described with reference to accompanying drawings and
examples. ^^OL ^
Dated this l^day of July 2012 \VC/ / ^
of Anand & Anand Advocates
Agents for the applicants