JP7364103B2 - power converter - Google Patents

Description

The present invention relates to a power conversion device, and particularly to a power conversion device including a plurality of semiconductor modules.

2. Description of the Related Art Conventionally, a power conversion device including a plurality of semiconductor modules is known (for example, see Patent Document 1).

The above-mentioned Patent Document 1 discloses a power conversion device including a plurality of semiconductor modules housing two switching elements. Furthermore, two capacitors are provided in parallel to the plurality of semiconductor modules. Further, wiring is provided to electrically connect the plurality of semiconductor modules and the two capacitors. Note that parasitic inductance exists in this wiring. In Patent Document 1, the wiring is composed of stacked bus bars in order to reduce parasitic inductance.

Specifically, in Patent Document 1, the positive side electrodes of two capacitors and the positive side electrodes of a plurality of semiconductor modules are electrically connected by a bus bar (hereinafter referred to as a positive side bus bar). Further, the negative side electrodes of the two capacitors and the negative side electrodes of the plurality of semiconductor modules are electrically connected by a bus bar (hereinafter referred to as a negative side bus bar).

In Patent Document 1, both the positive bus bar and the negative bus bar are made of copper plates having a substantially U-shape. A substantially U-shaped positive bus bar is arranged inside the substantially U-shaped negative bus bar. Furthermore, two capacitors are arranged inside the approximately U-shaped positive bus bar. Moreover, the negative side electrodes of the plurality of semiconductor modules are electrically connected to the bottom of the approximately U-shaped negative side bus bar. Although not specified in Patent Document 1, the positive electrodes of the plurality of semiconductor modules are electrically connected to the bottom of the approximately U-shaped positive bus bar through holes provided in the negative bus bar. It is thought that it is connected to. Further, the power conversion device of Patent Document 1 outputs power at two levels of potential, an upper potential and an intermediate potential.

JP2016-213945A

Here, the configuration in which a substantially U-shaped positive side bus bar and a substantially U-shaped negative side bus bar are provided as described in Patent Document 1 is replaced by three potentials: an upper potential, an intermediate potential, and a lower potential. When applied to a power conversion device that outputs power at a level potential, it is necessary to provide a substantially U-shaped intermediate potential side bus bar in addition to a substantially U-shaped positive side bus bar and a substantially U-shaped negative side bus bar. It is thought that there is. That is, the positive side busbar, the intermediate potential side busbar, and the negative side busbar are stacked. For example, a negative bus bar, an intermediate potential bus bar, and a positive bus bar are stacked in this order from the semiconductor module side. In order to connect the positive side electrode of the semiconductor module to the positive side bus bar, the positive side electrode of the semiconductor module is connected to the positive side bus bar through the hole provided in the negative side bus bar and the intermediate potential side bus bar. There is a need. For this reason, it is necessary to form a relatively large number of holes in the conductor such as the negative side bus bar or the intermediate potential side bus bar, resulting in a problem that the structure of the conductor becomes complicated.

This invention was made to solve the above-mentioned problems, and one object of the invention is to suppress the complexity of the conductor structure while reducing the parasitic inductance of the wiring. It is an object of the present invention to provide a power conversion device that is possible.

In order to achieve the above object, a power conversion device according to one aspect of the present invention is a power conversion device that outputs power at three levels of potential: an upper potential, an intermediate potential, and a lower potential, and which A plurality of semiconductor modules housed inside, a first capacitor and a second capacitor electrically connected to the plurality of semiconductor modules and connected to each other in series, a positive terminal of the first capacitor and a positive terminal of the semiconductor module. a positive potential conductor electrically connected to the terminal, a negative potential conductor electrically connected to the negative terminal of the second capacitor and the negative terminal of the semiconductor module, and a first capacitor and a second capacitor connected in series with each other. an intermediate potential conductor electrically connected to a connection point with the intermediate potential conductor, the intermediate potential conductor having a substantially U-shape, and a first capacitor and a second capacitor disposed inside the substantially U-shaped intermediate potential conductor. The positive potential conductor, the intermediate potential conductor, and the negative potential conductor do not overlap each other when viewed from the direction perpendicular to the plane on which the plurality of semiconductor modules are arranged. The negative potential conductors are arranged adjacent to each other in this order along the arrangement direction of the plurality of semiconductor modules, and the positive potential conductor has a bottom portion extending on the opposite side from the intermediate potential conductor, and a bottom portion of the positive potential conductor. The negative electrode potential conductor has a substantially L-shape including a terminal portion at a position adjacent to the intermediate potential conductor, and the negative electrode potential conductor has a bottom portion extending on the opposite side from the intermediate potential conductor, and a negative electrode potential conductor adjacent to the intermediate potential conductor at the bottom portion. The positive electrode potential conductor and the positive electrode potential conductor are electrically connected to the terminals of the semiconductor module at the respective terminal portions.

In the power conversion device according to one aspect of the present invention, as described above, the positive potential conductor, the intermediate potential conductor, and the negative potential conductor overlap each other when viewed from the direction perpendicular to the plane on which the plurality of semiconductor modules are arranged. In this state, the positive potential conductor, the intermediate potential conductor, and the negative potential conductor are arranged adjacent to each other in this order along the arrangement direction of the plurality of semiconductor modules. Thereby, the semiconductor module and the positive potential conductor can be electrically connected without using the intermediate potential conductor and the negative potential conductor. Similarly, the semiconductor module and the intermediate potential conductor can be electrically connected without using the positive potential conductor and the negative potential conductor. Similarly, the semiconductor module and the negative potential conductor can be electrically connected without using the positive potential conductor and the intermediate potential conductor. As a result, the number of holes formed in the positive potential conductor, intermediate potential conductor, and negative potential conductor can be reduced, so that the configuration of the conductors (positive potential conductor, intermediate potential conductor, and negative potential conductor) becomes complicated. can be suppressed. Furthermore, since the positive potential conductor, intermediate potential conductor, and negative potential conductor are arranged adjacent to each other, parasitic inductance between the positive potential conductor, intermediate potential conductor, and negative potential conductor can be reduced. As a result, it is possible to suppress the complexity of the conductor structure while reducing the parasitic inductance of the wiring.

In the power conversion device according to the first aspect, preferably, the bottom of the positive potential conductor and the bottom of the negative potential conductor are each electrically connected to the semiconductor module without an intermediate potential conductor. With this configuration, the semiconductor module can be electrically connected to each of the bottom of the positive potential conductor and the bottom of the negative potential conductor without providing a hole in the intermediate potential conductor.

The power conversion device according to the first aspect preferably includes a substantially flat connecting conductor that electrically connects the plurality of semiconductor modules, and a substantially flat output conductor through which power from the plurality of semiconductor modules is output. further comprising, the set of the positive potential conductor and the negative potential conductor, the output conductor, and the connection conductor are arranged in an overlapping state when viewed from a direction perpendicular to the plane on which the plurality of semiconductor modules are arranged. , the semiconductor module is connected to either the positive potential conductor or the negative potential conductor via the output conductor and the connection conductor, not via the intermediate potential conductor. With this configuration, even when an output conductor and a connection conductor are provided, the semiconductor module can be electrically connected to each of the positive potential conductor and the negative potential conductor without providing a hole in the intermediate potential conductor. be able to.

The power conversion device according to the first aspect preferably further includes a cooling section in which a plurality of semiconductor modules are arranged, and each of the plurality of semiconductor modules is perpendicular to a surface of the cooling section in which a plurality of semiconductor modules are arranged. A plurality of semiconductor modules are arranged so that the longitudinal direction of the semiconductor modules is along the direction of the flow of cooling air flowing into the cooling section. With this configuration, power conversion in the direction perpendicular to the direction of the cooling air flow is more efficient than when multiple semiconductor modules are arranged so that the short side of the semiconductor module is along the direction of the cooling air flow. The length of the device can be shortened.

The power conversion device according to the first aspect preferably further includes a cooling section in which a plurality of semiconductor modules are arranged, and the first capacitor and the second capacitor are arranged along the direction of flow of cooling air flowing into the cooling section. are placed next to each other. With this configuration, compared to the case where the first capacitor and the second capacitor are arranged next to each other in the direction perpendicular to the direction of flow of cooling air, the power in the direction perpendicular to the direction of flow of cooling air is reduced. The length of the conversion device can be reduced.

In the power conversion device according to the above-described one aspect, preferably, the semiconductor element includes a first switching element, a second switching element, a third switching element, and a fourth switching element connected in series with each other, and a first switching element and a fourth switching element connected in series with each other. a first diode and a second diode electrically connected between a connection point of the two switching elements and a connection point of the third switching element and the fourth switching element and connected in series with each other; The semiconductor module houses a first semiconductor module that houses a first switching element and a second switching element, a second semiconductor module that houses a first diode and a second diode, and a third switching element and a fourth switching element. the first semiconductor module, the second semiconductor module, and the third semiconductor module are arranged in this order from one side to the other side in the arrangement direction, and the positive potential conductor and the third semiconductor module are arranged in this order from one side to the other side in the arrangement direction. , the intermediate potential conductor, and the negative potential conductor are arranged in this order from one side toward the other side in the arrangement direction. With this configuration, the first switching element and the positive potential conductor are arranged on one side in the arrangement direction, so the first switching element and the positive potential conductor can be electrically connected through a relatively short path. I can do it. Since the fourth switching element and the negative potential conductor are arranged on the other side in the arrangement direction, the fourth switching element and the negative potential conductor can be electrically connected through a relatively short path.

In the power conversion device according to the above-described one aspect, preferably, the semiconductor element includes a first switching element, a second switching element, a third switching element, and a fourth switching element connected in series with each other, and a first switching element and a fourth switching element connected in series with each other. a first diode and a second diode electrically connected between a connection point of the two switching elements and a connection point of the third switching element and the fourth switching element and connected in series with each other; The semiconductor module includes a fourth semiconductor module housing the first switching element and the first diode, a fifth semiconductor module housing the second switching element and the third switching element, and a fourth semiconductor module housing the fourth switching element and the second diode. a sixth semiconductor module, the fourth semiconductor module, the fifth semiconductor module, and the sixth semiconductor module are arranged in this order from one side to the other side in the arrangement direction, and the positive electrode potential conductor , the intermediate potential conductor, and the negative potential conductor are arranged in this order from one side toward the other side in the arrangement direction. With this configuration, the first switching element and the positive potential conductor are arranged on one side in the arrangement direction, so the first switching element and the positive potential conductor can be electrically connected through a relatively short path. I can do it. Since the fourth switching element and the negative potential conductor are arranged on the other side in the arrangement direction, the fourth switching element and the negative potential conductor can be electrically connected through a relatively short path.

According to the present invention, as described above, it is possible to reduce the parasitic inductance of the wiring while suppressing the configuration of the conductor from becoming complicated.

FIG. 1 is a circuit diagram of a power conversion device according to a first embodiment. FIG. 2 is a circuit diagram of a power conversion unit of the power conversion device according to the first embodiment. FIG. 3 is a top view of a plurality of semiconductor modules according to the first embodiment. FIG. 1 is a perspective view of a semiconductor module according to a first embodiment. FIG. 2 is a perspective view of the power conversion unit according to the first embodiment. FIG. 2 is an exploded perspective view of the power converter according to the first embodiment. FIG. 3 is an exploded side view of the power converter according to the first embodiment. FIG. 1 is a perspective view of a capacitor according to a first embodiment. FIG. 3 is a side view of the power conversion unit according to the first embodiment. FIG. 3 is a perspective view of the bottom surface of the intermediate potential conductor according to the first embodiment. FIG. 2 is a side perspective view (1) of the intermediate potential conductor according to the first embodiment. FIG. 2 is a side perspective view (2) of the intermediate potential conductor according to the first embodiment. FIG. 3 is a perspective view of an output conductor according to the first embodiment. FIG. 3 is a perspective view of the first connection conductor according to the first embodiment. FIG. 3 is a perspective view of the second connection conductor according to the first embodiment. FIG. 1 is a perspective view of a power conversion device according to a first embodiment. FIG. 3 is a circuit diagram of a power conversion unit of a power conversion device according to a second embodiment. FIG. 7 is a top view of a plurality of semiconductor modules according to a second embodiment. FIG. 7 is an exploded side view of a power converter according to a second embodiment. FIG. 7 is a circuit diagram of a power conversion unit of a power conversion device according to a modification.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments embodying the present invention will be described based on the drawings.

[First embodiment]
The configuration of a power conversion device 100 according to the first embodiment will be described with reference to FIGS. 1 to 16. As shown in FIG. 1, the power conversion device 100 is configured to output power at three levels of potential: an upper potential, an intermediate potential, and a lower potential. Note that the power conversion device 100 is provided in, for example, a railway vehicle. Furthermore, single-phase voltage is input from a pantograph 200 to a power conversion device 100 provided in a railway vehicle from a secondary winding 203 of a transformer 202 via a circuit breaker 201 .

Power conversion device 100 includes converter section 1 . The converter section 1 converts a single-phase voltage input from the secondary winding 203 into a DC voltage.

The power conversion device 100 includes an inverter section 2. The inverter section 2 converts the DC voltage input from the converter section 1 into an AC voltage. The converted AC voltage is then output from the inverter section 2 to the motor 204 for driving the railway vehicle.

Further, the converter section 1 is configured by two power conversion sections 10 that are connected in parallel to each other. Further, the inverter unit 2 is configured by three power converters 10 that are connected in parallel to each other. The configuration of one power conversion section 10 will be described below.

As shown in FIG. 2, the power conversion unit 10 includes a first switching element Q1, a second switching element Q2, a third switching element Q3, and a fourth switching element Q4 that are connected in series with each other. The first switching element Q1, the second switching element Q2, the third switching element Q3, and the fourth switching element Q4 are connected between the positive potential side P and the negative potential side N. Further, a diode D is connected in antiparallel to each of the first switching element Q1, the second switching element Q2, the third switching element Q3, and the fourth switching element Q4. Note that the first switching element Q1, the second switching element Q2, the third switching element Q3, and the fourth switching element Q4 are, for example, IGBTs (Insulated Gate Bipolar Transistors) made of silicon (Si) semiconductors. Note that the first switching element Q1, the second switching element Q2, the third switching element Q3, and the fourth switching element Q4 are examples of "semiconductor elements" in the claims.

The power conversion unit 10 also includes a first capacitor C1 and a second capacitor C2 connected in series between the positive potential side P and the negative potential side N. Note that the connection point between the first capacitor C1 and the second capacitor C2 is an intermediate potential point M. The first capacitor C1 and the second capacitor C2 are electrically connected in parallel to the first to fourth switching elements Q1 to Q4.

Further, the power conversion unit 10 is electrically connected to a connection point N1 between the first switching element Q1 and the second switching element Q2, and a connection point N2 between the third switching element Q3 and the fourth switching element Q4, and to each other. It includes a first diode D1 and a second diode D2 connected in series. Note that the first diode D1 and the second diode D2 function as clamp diodes. Further, the anode of the first diode D1 is electrically connected to the intermediate potential point M. Further, the cathode of the first diode D1 is electrically connected to the connection point N1. The anode of the second diode D2 is electrically connected to the connection point N2. Further, the cathode of the second diode D2 is electrically connected to the intermediate potential point M. Further, the first diode D1 and the second diode D2 are, for example, diodes made of silicon semiconductor. Note that the first diode D1 and the second diode D2 are an example of a "semiconductor element" in the claims.

Further, as shown in FIG. 3, the power conversion unit 10 is provided with a plurality of semiconductor modules 20 (20a, 20b, and 20c). The semiconductor module 20 houses any two of the first switching element Q1, the second switching element Q2, the third switching element Q3, the fourth switching element Q4, the first diode D1, and the second diode D2. It is configured as follows. As shown in FIG. 4, the semiconductor module 20 includes two first terminals 21, two second terminals 22, and three third terminals 23.

Further, as shown in FIGS. 5 and 6, the power conversion section 10 includes a cooling section 30. The cooling unit 30 includes a cooling unit main body 31 having a substantially flat plate shape, and radiation fins 32 extending downward (in the Z2 direction) from the cooling unit main body 31. Further, the plurality of semiconductor modules 20 are arranged on the upper surface 31a (Z1 direction side) of the cooling unit main body 31.

Here, in the first embodiment, as shown in FIG. 2, the plurality of semiconductor modules 20 include a first semiconductor module 20a, a second semiconductor module 20b, and a third semiconductor module 20c. The first semiconductor module 20a houses a first switching element Q1 and a second switching element Q2. Further, the second semiconductor module 20b houses a first diode D1 and a second diode D2. Further, the third semiconductor module 20c houses a third switching element Q3 and a fourth switching element Q4.

In the first embodiment, as shown in FIG. 3, the first semiconductor module 20a, the second semiconductor module 20b, and the third semiconductor module 20c are arranged in this order in the arrangement direction of the plurality of semiconductor modules 20. They are arranged from one side (X1 direction side) to the other side (X2 direction side) in the X direction. Note that the first semiconductor module 20a, the second semiconductor module 20b, and the third semiconductor module 20c each have a first terminal 21 (21a, 21b, and 21c), a second terminal 21 (21a, 21b, and 21c), The terminals 22 (22a, 22b and 22c) and the third terminals 23 (23a, 23b and 23c) are arranged in this order. Note that two first semiconductor modules 20a, two second semiconductor modules 20b, and two third semiconductor modules 20c are provided. The two first semiconductor modules 20a (two second semiconductor modules 20b, two third semiconductor modules 20c) are electrically connected in parallel. Note that the first terminal 21a is an example of a "positive terminal of a semiconductor module" in the claims. Further, the second terminal 22c is an example of a "negative terminal of a semiconductor module" in the claims.

Note that when the power conversion device 100 is provided in a railway vehicle, the X direction corresponds to the traveling direction of the railway vehicle.

Further, as shown in FIG. 2, the first terminal 21a of the first semiconductor module 20a is a collector (C) terminal. Further, the second terminal 22a of the first semiconductor module 20a is an emitter (E) terminal. Further, the third terminal 23a of the first semiconductor module 20a is an output terminal.

Further, the first terminal 21b of the second semiconductor module 20b is a cathode (K) terminal. Further, the second terminal 22b of the second semiconductor module 20b is an anode (A) terminal. Further, the third terminal 23b of the second semiconductor module 20b is an output terminal.

Further, the first terminal 21c of the third semiconductor module 20c is a collector terminal. Further, the second terminal 22c of the third semiconductor module 20c is an emitter terminal. Further, the third terminal 23c of the third semiconductor module 20c is an output terminal.

Here, in the first embodiment, as shown in FIG. 3, each of the plurality of semiconductor modules 20 is It has a substantially rectangular shape. The plurality of semiconductor modules 20 are arranged such that the longitudinal direction of the semiconductor modules 20 is along the flow direction (X direction) of the cooling air flowing into the cooling unit 30. Specifically, the two first semiconductor modules 20a are arranged adjacent to each other along the Y direction. Similarly, the two second semiconductor modules 20b are arranged adjacent to each other along the Y direction. Similarly, the two third semiconductor modules 20c are arranged adjacent to each other along the Y direction. The first semiconductor module 20a, the second semiconductor module 20b, and the third semiconductor module 20c are arranged adjacent to each other in this order along the X direction.

Further, as shown in FIGS. 7 and 9, the power converter 10 includes a positive potential conductor 40. The positive potential conductor 40 is electrically connected to the positive terminal C1p (see FIG. 8) of the first capacitor C1 and the first terminal 21a of the first semiconductor module 20a.

Further, as shown in FIGS. 7 and 9, the power converter 10 includes a negative potential conductor 50. The negative potential conductor 50 is electrically connected to the negative terminal C2n of the second capacitor C2 and the second terminal 22c of the third semiconductor module 20c.

Here, in the first embodiment, as shown in FIGS. 7 and 9, the positive potential conductor 40 and the negative potential conductor 50 have a substantially L-shape. A bottom portion 41 of the approximately L-shaped positive electrode potential conductor 40 along the X direction and a bottom portion 51 of the approximately L-shaped negative electrode potential conductor 50 along the X direction are located on the opposite side of the intermediate potential conductor 60, which will be described later. It is extending. Specifically, the bottom portion 41 of the positive electrode potential conductor 40 extends in the X1 direction. Further, the bottom portion 51 of the negative electrode potential conductor 50 extends in the X2 direction. The bottom portion 41 of the positive potential conductor 40 is arranged vertically above the first terminal 21a of the first semiconductor module 20a. Further, the bottom portion 51 of the negative electrode potential conductor 50 is arranged vertically above the second terminal 22c of the third semiconductor module 20c.

Further, the power conversion unit 10 includes an intermediate potential conductor 60. The intermediate potential conductor 60 is electrically connected to a connection point (intermediate potential point M) between the first capacitor C1 and the second capacitor C2, which are connected in series with each other. Specifically, the intermediate potential conductor 60 is electrically connected to the negative terminal C1n of the first capacitor C1, the positive terminal C2p of the second capacitor C2, and the third terminal 23b of the second semiconductor module 20b.

Further, the intermediate potential conductor 60 has a substantially U-shape. Further, the intermediate potential conductor 60 has a flat plate shape. A first capacitor C1 and a second capacitor C2 are arranged inside the substantially U-shaped intermediate potential conductor 60.

Further, the intermediate potential conductor 60 includes a bottom surface 61 (see FIG. 10), and side surfaces 62 (see FIG. 11) and side surfaces 63 (see FIG. 12) corresponding to the side portions. Note that the configuration of the side surface 62 is similar to the configuration of the positive electrode potential conductor 40. Further, the configuration of the side surface 63 is similar to the configuration of the negative electrode potential conductor 50.

Further, in the first embodiment, as shown in FIGS. 5 and 6, the first capacitor C1 and the second capacitor C2 are adjacent to each other along the flow direction (X direction) of the cooling air flowing into the cooling section 30. It is arranged like this. Further, the first capacitor C1 (second capacitor C2) has a substantially rectangular shape when viewed from the Z direction. The first capacitor C1 (second capacitor C2) is arranged such that the longitudinal direction of the first capacitor C1 (second capacitor C2) is along the Y direction.

Further, as shown in FIG. 9, the power conversion unit 10 includes a first connection conductor 70 and a second connection conductor 80 having a substantially flat plate shape that electrically connect the plurality of semiconductor modules 20 to each other. The first connection conductor 70 electrically connects the third terminal 23a of the first semiconductor module 20a and the first terminal 21b of the second semiconductor module 20b. Further, the second connection conductor 80 electrically connects the second terminal 22b of the second semiconductor module 20b and the third terminal 23c of the third semiconductor module 20c. Note that the first connecting conductor 70 and the second connecting conductor 80 are an example of a "connecting conductor" in the claims.

The power converter 10 also includes a substantially flat output conductor 90 through which power from the plurality of semiconductor modules 20 is output. Specifically, the output conductor 90 electrically connects the second terminal 22a of the first semiconductor module 20a and the first terminal 21c of the third semiconductor module 20c.

Here, in the first embodiment, when viewed from the direction (Z direction) perpendicular to the surface on which the plurality of semiconductor modules 20 are arranged (the surface 31a of the cooling section main body section 31), the positive electrode potential conductor 40 and the intermediate potential conductor 60 and the negative potential conductor 50 do not overlap with each other. Then, in this state that they do not overlap with each other, the positive potential conductor 40, the intermediate potential conductor 60, and the negative potential conductor 50 are placed in this order on the X1 direction side along the X direction, which is the arrangement direction of the plurality of semiconductor modules 20. They are arranged adjacent to each other toward the X2 direction side.

Further, in the first embodiment, along the direction (Z direction) perpendicular to the surface on which the plurality of semiconductor modules 20 are arranged, the set of the positive electrode potential conductor 40 and the negative electrode potential conductor 50, the output conductor 90, and the first The connecting conductor 70 (second connecting conductor 80) is laminated. Then, the semiconductor module 20 connects to either the positive potential conductor 40 or the negative potential conductor 50 via the output conductor 90 and the first connection conductor 70 (second connection conductor 80), not through the intermediate potential conductor 60. connected to the crab. This will be explained in detail below.

The first connecting conductor 70 and the second connecting conductor 80 are arranged so that they are adjacent to each other on the same plane (on the XY plane) at a position closest to the semiconductor module 20 (between the semiconductor module 20 and the output conductor 90). It is located in The first terminal 71 of the first connection conductor 70 is electrically connected to the third terminal 23a of the first semiconductor module 20a. Further, the second terminal 72 of the first connection conductor 70 is electrically connected to the first terminal 21b of the second semiconductor module 20b.

Further, the first terminal 81 of the second connection conductor 80 is electrically connected to the second terminal 22b of the second semiconductor module 20b. Further, the second terminal 82 of the second connection conductor 80 is electrically connected to the third terminal 23c of the third semiconductor module 20c.

The output conductor 90 is arranged above (on the Z1 direction side) the first connection conductor 70 and the second connection conductor 80 which are arranged adjacent to each other. The first terminal 91 of the output conductor 90 is electrically connected to the second terminal 22a of the first semiconductor module 20a via the hole 70a of the first connection conductor 70 (see FIG. 14). The second terminal 92 of the output conductor 90 is electrically connected to the first terminal 21c of the third semiconductor module 20c via the hole 80a of the second connection conductor 80 (see FIG. 15). The output terminal 93 of the output conductor 90 is arranged on the third semiconductor module 20c side (X2 direction side).

As shown in FIG. 9, the bottom surface 61 of the intermediate potential conductor 60 is arranged above the output conductor 90 (on the Z1 direction side). Further, the side surface 62 of the intermediate potential conductor 60 is arranged to face the side surface C1s on which the positive terminal C1p and the negative terminal C1n of the first capacitor C1 are provided. Further, the side surface 63 of the intermediate potential conductor 60 is arranged to face the side surface C2s on which the positive terminal C2p and the negative terminal C2n of the second capacitor C2 are provided.

A side surface 62 of the intermediate potential conductor 60 is electrically connected to the negative terminal C1n of the first capacitor C1. A side surface 63 of the intermediate potential conductor 60 is electrically connected to the positive terminal C2p of the second capacitor C2. The terminal 64 of the intermediate potential conductor 60 is connected to the third terminal of the second semiconductor module 20b via the hole 90a of the output conductor 90 (see FIG. 13) and the hole 80b of the second connection conductor 80 (see FIG. 15). It is electrically connected to the terminal 23b.

Further, the positive potential conductor 40 is arranged to face the side surface 62 of the intermediate potential conductor 60 in the X direction. The positive potential conductor 40 is electrically connected to the positive terminal C1p of the first capacitor C1 through a hole in the side surface 62 of the intermediate potential conductor 60. Further, in the first embodiment, the bottom part 41 (terminal 42) of the positive electrode potential conductor 40 is connected to the hole 90b of the output conductor 90 (see FIG. 13) and the hole of the first connection conductor 70 without intervening the intermediate potential conductor 60. It is electrically connected to the first terminal 21a of the first semiconductor module 20a via the portion 70b (see FIG. 14).

The negative potential conductor 50 is arranged to face the side surface 63 of the intermediate potential conductor 60 in the X direction. The negative potential conductor 50 is electrically connected to the negative terminal C2n of the second capacitor C2 through a hole in the side surface 63 of the intermediate potential conductor 60. Further, in the first embodiment, the bottom portion 51 (terminal 52) of the negative electrode potential conductor 50 is connected to the hole 90c of the output conductor 90 (see FIG. 13) and the hole of the second connection conductor 80 without intervening the intermediate potential conductor 60. It is electrically connected to the second terminal 22c of the third semiconductor module 20c via the portion 80c (see FIG. 15).

Here, when the first switching element Q1 to the fourth switching element Q4 perform a switching operation, the direction of the commutation current flowing through the intermediate potential conductor 60 (direction along the Z direction) is the same as the commutation current flowing through the positive potential conductor 40. The direction of the current and the direction of the commutation current flowing through the negative electrode potential conductor 50 are opposite. Further, the direction of the commutation current flowing through the intermediate potential conductor 60 (direction along the X direction) is opposite to the direction of the commutation current flowing through the output conductor 90, the first connection conductor 70, and the second connection conductor 80. Become. Therefore, it is possible to reduce the inductance of one round of the commutation path.

Further, the first capacitor C1 and the second capacitor C2 each have an internal inductance. Therefore, the inductance of a circuit on the upper potential side including one first capacitor C1 for each phase becomes relatively large. Similarly, the inductance of a circuit on the lower potential side including one second capacitor C2 for each phase is relatively large. Therefore, by connecting the upper potential side, the lower potential side, and the intermediate potential through a plurality of capacitors (C1 and C2), it is possible to reduce the inductance of one round of the commutation path.

FIG. 16 is a perspective view of the power conversion device 100 arranged on one cooling unit main body 31. As shown in FIG. As shown in FIG. 16, five power converters 10, which constitute the converter section 1 and the inverter section 2, are provided on the cooling section main body section 31. The positive potential conductor 40, the negative potential conductor 50, the intermediate potential conductor 60, the output conductor 90, the first connection conductor 70, and the second connection conductor 80 are respectively common to the five power conversion units 10. (one each) provided. Note that even when the cooling unit main body 31 is provided for every five power conversion units 10, the positive electrode potential conductor 40, the negative electrode potential conductor 50, the intermediate potential conductor 60, the output conductor 90, the first connection conductor 70, and the The two connection conductors 80 can be provided in common (one each) for the five power conversion units 10, respectively.

[Effects of the first embodiment]
In the first embodiment, the following effects can be obtained.

In the first embodiment, as described above, the positive potential conductor 40, the intermediate potential conductor 60, and the negative potential conductor 50 do not overlap each other when viewed from the direction perpendicular to the plane on which the plurality of semiconductor modules 20 are arranged. The positive potential conductor 40, the intermediate potential conductor 60, and the negative potential conductor 50 are arranged adjacent to each other in this order along the arrangement direction of the plurality of semiconductor modules 20. Thereby, the semiconductor module 20 and the positive potential conductor 40 can be electrically connected without intervening the intermediate potential conductor 60 and the negative potential conductor 50. Similarly, the semiconductor module 20 and the intermediate potential conductor 60 can be electrically connected without using the positive potential conductor 40 and the negative potential conductor 50. Similarly, the semiconductor module 20 and the negative potential conductor 50 can be electrically connected without using the positive potential conductor 40 and the intermediate potential conductor 60. As a result, the number of holes formed in the positive potential conductor 40, intermediate potential conductor 60, and negative potential conductor 50 can be reduced, so that the conductors (positive potential conductor 40, intermediate potential conductor 60, and negative potential conductor 50) It is possible to suppress the configuration from becoming complicated. Furthermore, since the positive potential conductor 40, the intermediate potential conductor 60, and the negative potential conductor 50 are arranged adjacent to each other, the parasitic inductance between the positive potential conductor 40, the intermediate potential conductor 60, and the negative potential conductor 50 is reduced. be able to. As a result, it is possible to suppress the complexity of the conductor structure while reducing the parasitic inductance of the wiring.

Further, in the first embodiment, as described above, the bottom portion 41 of the approximately L-shaped positive electrode potential conductor 40 along the X direction and the bottom portion 51 of the approximately L-shaped negative electrode potential conductor 50 along the X direction are as follows. It extends on the opposite side from the intermediate potential conductor 60. Thereby, since the bottom portion 41 of the positive electrode potential conductor 40 extends on the opposite side from the intermediate potential conductor 60, the positive electrode potential conductor 40 can be brought closer to the intermediate potential conductor 60. Similarly, since the bottom portion 51 of the negative potential conductor 50 extends on the opposite side from the intermediate potential conductor 60, the negative potential conductor 50 can be brought close to the intermediate potential conductor 60. Thereby, the parasitic inductance of the wiring can be effectively reduced.

Furthermore, in the first embodiment, as described above, the bottom portion 41 of the positive potential conductor 40 and the bottom portion 51 of the negative potential conductor 50 are electrically connected to the semiconductor module 20 without intervening the intermediate potential conductor 60. It is connected. Thereby, the semiconductor module 20 can be electrically connected to each of the bottom 41 of the positive potential conductor 40 and the bottom 51 of the negative potential conductor 50 without providing a hole in the intermediate potential conductor 60.

Further, in the first embodiment, as described above, along the direction perpendicular to the plane on which the plurality of semiconductor modules 20 are arranged, the set of the positive electrode potential conductor 40 and the negative electrode potential conductor 50, the output conductor 90, and the 1 connection conductor 70 (second connection conductor 80) are stacked, and the semiconductor module 20 connects the output conductor 90 and the first connection conductor 70 (second connection conductor 80) without intervening the intermediate potential conductor 60. It is connected to either the positive potential conductor 40 or the negative potential conductor 50 via the negative potential conductor 40 . As a result, even when the output conductor 90 and the first connection conductor 70 (second connection conductor 80) are provided, each of the positive potential conductor 40 and the negative potential conductor 50 can be connected without providing a hole in the intermediate potential conductor 60. The semiconductor module 20 can be electrically connected to the semiconductor module 20 .

Further, in the first embodiment, as described above, the plurality of semiconductor modules 20 are arranged such that the longitudinal direction of the semiconductor modules 20 is along the flow direction of the cooling air flowing into the cooling unit 30. As a result, compared to a case where a plurality of semiconductor modules 20 are arranged such that the width direction of the semiconductor modules 20 is along the direction of the flow of the cooling air, the power converter 100 is arranged in a direction perpendicular to the direction of the flow of the cooling air. The length of can be shortened.

Further, in the first embodiment, as described above, the first capacitor C1 and the second capacitor C2 are arranged adjacent to each other along the flow direction of the cooling air flowing into the cooling section 30. As a result, compared to the case where the first capacitor C1 and the second capacitor C2 are arranged next to each other in the direction perpendicular to the direction of the flow of the cooling air, the power converter in the direction perpendicular to the direction of the flow of the cooling air 100 length can be shortened.

Further, in the first embodiment, as described above, the first semiconductor module 20a, the second semiconductor module 20b, and the third semiconductor module 20c are arranged in this order from one side to the other side in the arrangement direction (X direction). The positive electrode potential conductor 40, the intermediate potential conductor 60, and the negative electrode potential conductor 50 are arranged in this order from one side toward the other side in the arrangement direction. As a result, the first switching element Q1 and the positive potential conductor 40 are arranged on one side in the X direction, so that the first switching element Q1 and the positive potential conductor 40 can be electrically connected through a relatively short path. I can do it. Since the fourth switching element Q4 and the negative potential conductor 50 are arranged on the other side in the X direction, the fourth switching element Q4 and the negative potential conductor 50 can be electrically connected through a relatively short path.

[Second embodiment]
The configuration of the power conversion unit 300 according to the second embodiment will be described with reference to FIGS. 17 to 19. In the power conversion unit 300 according to the second embodiment, the type of semiconductor element housed in the semiconductor module 320 is different from that in the first embodiment.

In the second embodiment, as shown in FIG. 17, the power conversion unit 300 includes a first semiconductor module 320a, a second semiconductor module 320b, and a third semiconductor module 320c. The first semiconductor module 320a houses a first switching element Q1 and a first diode D1. Further, the second semiconductor module 320b houses a second switching element Q2 and a third switching element Q3. Further, the third semiconductor module 320c houses a fourth switching element Q4 and a second diode D2. As shown in FIG. 18, the first semiconductor module 320a, the second semiconductor module 320b, and the third semiconductor module 320c are arranged in this order from one side in the X direction (X1 direction side) to the other side (X2 direction side). side). Note that the first semiconductor module 320a and the second semiconductor module 320b are examples of a "fourth semiconductor module" and a "fifth semiconductor module" in the claims, respectively. Further, the third semiconductor module 320c is an example of a "sixth semiconductor module" in the claims.

Further, as shown in FIGS. 17 and 18, the first terminal 321a of the first semiconductor module 320a is a collector (C) terminal. Further, the second terminal 322a of the first semiconductor module 320a is an anode (A) terminal. Further, the third terminal 323a of the first semiconductor module 320a is an output terminal.

Further, the first terminal 321b of the second semiconductor module 320b is a collector terminal. Further, the second terminal 322b of the second semiconductor module 320b is an emitter (E) terminal. Further, the third terminal 323b of the second semiconductor module 320b is an output terminal.

Further, the first terminal 321c of the third semiconductor module 320c is a cathode (K) terminal. Further, the second terminal 322c of the third semiconductor module 320c is an emitter terminal. Further, the third terminal 323c of the third semiconductor module 320c is an output terminal. Note that the first terminal 321a is an example of a "positive terminal of a semiconductor module" in the claims. Further, the second terminal 322c is an example of a "negative terminal of a semiconductor module" in the claims.

Further, in the second embodiment, as shown in FIG. 19, the power conversion unit 300 includes a positive potential conductor 340, an intermediate potential conductor 360, and a negative potential conductor, similarly to the power conversion unit 10 of the first embodiment. 350, a first connection conductor 370, a second connection conductor 380, and an output conductor 390. The positive potential conductor 340, the intermediate potential conductor 360, and the negative potential conductor 350 are arranged in this order from one side (X1 direction side) to the other side (X2 direction side) in the X direction. . The intermediate potential conductor 360 includes two terminals 361 and 362, unlike the intermediate potential conductor 60 of the first embodiment. The terminal 361 is electrically connected to the second terminal 322a of the first semiconductor module 320a. Further, the terminal 362 is electrically connected to the first terminal 321c of the third semiconductor module 320c. Note that the configurations of the other conductors (positive electrode potential conductor 340, negative electrode potential conductor 350, first connection conductor 370, second connection conductor 380, and output conductor 390) differ in the positions of holes etc. The structure is similar to that of the conductor in the embodiment.

[Effects of second embodiment]
In the second embodiment, the following effects can be obtained.

In the second embodiment, as described above, the first semiconductor module 320a, the second semiconductor module 320b, and the third semiconductor module 320c are arranged in this order from one side to the other side in the X direction. The positive potential conductor 340, the intermediate potential conductor 360, and the negative potential conductor 350 are arranged in this order from one side to the other side in the X direction. As a result, the first switching element Q1 and the positive potential conductor 340 are arranged on one side in the X direction, so that the first switching element Q1 and the positive potential conductor 340 can be electrically connected through a relatively short path. I can do it. Since the fourth switching element Q4 and the negative potential conductor 350 are arranged on the other side in the X direction, the fourth switching element Q4 and the negative potential conductor 350 can be electrically connected through a relatively short path.

Note that other effects of the second embodiment are similar to those of the first embodiment.

[Modified example]
Note that the embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims rather than the description of the embodiments described above, and further includes all changes (modifications) within the meaning and range equivalent to the claims.

For example, in the first and second embodiments described above, an example is shown in which the positive electrode potential conductor and the negative electrode potential conductor have a substantially L-shape, but the present invention is not limited to this. For example, the positive electrode potential conductor and the negative electrode potential conductor may have a shape other than a substantially L-shape (such as a substantially I-shape).

Further, in the first and second embodiments described above, an example was shown in which the semiconductor module has a substantially rectangular shape, but the present invention is not limited to this. For example, the semiconductor module may have a shape other than a substantially rectangular shape (such as a substantially square shape).

Further, in the first and second embodiments described above, an example was shown in which a plurality of semiconductor modules are arranged so that the longitudinal direction of the semiconductor modules is along the direction of the flow of cooling air flowing into the cooling section. The invention is not limited to this. For example, a plurality of semiconductor modules may be arranged such that the longitudinal direction of the semiconductor modules is along a direction perpendicular to the direction of the flow of cooling air flowing through the cooling section.

Further, in the first and second embodiments, the first semiconductor module, the second semiconductor module, and the third semiconductor module are arranged along the flow direction of the cooling air flowing into the cooling section (the running direction of the railway vehicle). Although an example has been shown in which these are arranged, the present invention is not limited to this. For example, the first semiconductor module, the second semiconductor module, and the third semiconductor module may be arranged along a direction (sleeper direction) orthogonal to the direction of the flow of cooling air flowing through the cooling section.

Further, in the first and second embodiments described above, an example was shown in which two elements (two switching elements, one switching element and one diode, or two diodes) are housed in one semiconductor module. However, the present invention is not limited to this. For example, one or more elements may be housed in one semiconductor module.

Further, in the first and second embodiments described above, an example was shown in which the switching element is an IGBT made of a silicon semiconductor, but the present invention is not limited to this. For example, switching elements Q11, Q12, Q13, and Q14 may be configured with MOSFETs, as in a power conversion section 400 according to a modified example shown in FIG. 20. Furthermore, at least one of the switching element and the diode may be made of a wide bandgap semiconductor.

10, 300, 400 power conversion unit 20, 320 semiconductor module 20a first semiconductor module 20b second semiconductor module 20c third semiconductor module 21a, 321a first terminal (positive terminal of semiconductor module)
22c, 322c 2nd terminal (negative terminal of semiconductor module)
30 Cooling part 31a Surface (surface on which semiconductor module is placed)
40, 340 Positive electrode potential conductor 41 Bottom portion 50 Negative electrode potential conductor 51 Bottom portion 70, 370 First connection conductor (connection conductor)
80, 380 Second connection conductor (connection conductor)
90, 390 output conductor 100 power conversion device 320a first semiconductor module (fourth semiconductor module)
320b First semiconductor module (fifth semiconductor module)
320c First semiconductor module (sixth semiconductor module)
C1 First capacitor C1p Positive terminal C2 Second capacitor C2n Negative terminal D1 First diode (semiconductor element)
D2 Second diode (semiconductor element)
Q1 First switching element (semiconductor element)
Q2 Second switching element (semiconductor element)
Q3 Third switching element (semiconductor element)
Q4 Fourth switching element (semiconductor element)

Claims (7)

A power conversion device that outputs power at three levels of potential: an upper potential, an intermediate potential, and a lower potential,
a plurality of semiconductor modules that house semiconductor elements inside;
a first capacitor and a second capacitor electrically connected to the plurality of semiconductor modules and connected in series with each other;
a positive potential conductor electrically connected to the positive terminal of the first capacitor and the positive terminal of the semiconductor module;
a negative potential conductor electrically connected to the negative terminal of the second capacitor and the negative terminal of the semiconductor module;
an intermediate potential conductor electrically connected to a connection point between the first capacitor and the second capacitor that are connected in series with each other;
The intermediate potential conductor has a substantially U-shape, and the first capacitor and the second capacitor are arranged inside the substantially U-shaped intermediate potential conductor,
The positive potential conductor and the intermediate potential conductor are arranged in a state in which the positive potential conductor, the intermediate potential conductor, and the negative potential conductor do not overlap each other when viewed from a direction perpendicular to a plane on which the plurality of semiconductor modules are arranged. and the negative electrode potential conductor are arranged adjacent to each other in this order along the arrangement direction of the plurality of semiconductor modules,
The positive electrode potential conductor has a substantially L-shape including a bottom portion extending on the opposite side from the intermediate potential conductor, and a terminal portion at a position adjacent to the intermediate potential conductor on the bottom portion,
The negative electrode potential conductor has a substantially L-shape including a bottom portion extending on the opposite side from the intermediate potential conductor, and a terminal portion at a position adjacent to the intermediate potential conductor on the bottom portion,
A power converter device in which the positive potential conductor and the negative potential conductor are electrically connected to terminals of the semiconductor module at their respective terminal portions. The power conversion device according to claim 1, wherein a bottom portion of the positive potential conductor and a bottom portion of the negative potential conductor are each electrically connected to the semiconductor module without intervening the intermediate potential conductor. a substantially flat connecting conductor that electrically connects the plurality of semiconductor modules;
further comprising a substantially flat output conductor through which power from the plurality of semiconductor modules is output;
When viewed from a direction perpendicular to a plane on which the plurality of semiconductor modules are arranged, the set of the positive potential conductor and the negative potential conductor, the output conductor, and the connection conductor are arranged in an overlapping state. Ori,
2. The semiconductor module according to claim 1, wherein the semiconductor module is connected to one of the positive potential conductor and the negative potential conductor through the output conductor and the connection conductor, not through the intermediate potential conductor. 2. The power conversion device according to 2. further comprising a cooling section in which the plurality of semiconductor modules are arranged,
Each of the plurality of semiconductor modules has a substantially rectangular shape when viewed from a direction perpendicular to the surface of the cooling unit in which the plurality of semiconductor modules are arranged,
The power converter according to any one of claims 1 to 3, wherein the plurality of semiconductor modules are arranged so that the longitudinal direction of the semiconductor modules is along the direction of a flow of cooling air flowing into the cooling section. Device. further comprising a cooling section in which the plurality of semiconductor modules are arranged,
The power converter according to any one of claims 1 to 3, wherein the first capacitor and the second capacitor are arranged adjacent to each other along the direction of a flow of cooling air flowing into the cooling section. Device. The semiconductor element includes a first switching element, a second switching element, a third switching element, and a fourth switching element connected in series with each other, a connection point between the first switching element and the second switching element, and a connection point between the first switching element and the second switching element; a first diode and a second diode electrically connected between the three switching elements and the connection point of the fourth switching element and connected in series with each other;
The plurality of semiconductor modules include a first semiconductor module housing the first switching element and the second switching element, a second semiconductor module housing the first diode and the second diode, and a third switching element. and a third semiconductor module housing the fourth switching element,
The first semiconductor module, the second semiconductor module, and the third semiconductor module are arranged in this order from one side to the other side in the arrangement direction,
Any one of claims 1 to 5, wherein the positive potential conductor, the intermediate potential conductor, and the negative potential conductor are arranged in this order from one side to the other side in the arrangement direction. The power conversion device described in . The semiconductor element includes a first switching element, a second switching element, a third switching element, and a fourth switching element connected in series with each other, a connection point between the first switching element and the second switching element, and a connection point between the first switching element and the second switching element; a first diode and a second diode electrically connected between the three switching elements and the connection point of the fourth switching element and connected in series with each other;
The plurality of semiconductor modules include a fourth semiconductor module housing the first switching element and the first diode, a fifth semiconductor module housing the second switching element and the third switching element, and the fourth semiconductor module housing the second switching element and the third switching element. a sixth semiconductor module that houses the element and the second diode,
The fourth semiconductor module, the fifth semiconductor module, and the sixth semiconductor module are arranged in this order from one side to the other side in the arrangement direction,
Any one of claims 1 to 5, wherein the positive potential conductor, the intermediate potential conductor, and the negative potential conductor are arranged in this order from one side to the other side in the arrangement direction. The power conversion device described in .

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