Power conversion device

Abstract

Provided is a power conversion device. In the power conversion device, at least one of a positive electrode conductor and a negative electrode conductor is integrally configured in a manner shared by at least a plurality of phase semiconductor modules of each phase semiconductor module, and is composed of aluminum.

Description

TECHNICAL FIELD

[0001] The present application relates to a power conversion device, and particularly to a power conversion device provided with a plurality of semiconductor modules. BACKGROUND

[0002] Conventionally, a power conversion device provided with a plurality of semiconductor modules is known. Such a power conversion device is disclosed in Japanese Patent Application Publication No. 2016-213945, for example.

[0003] In Japanese Patent Application Publication No. 2016-213945, a power conversion device provided with a plurality of semiconductor modules is disclosed, the semiconductor modules housing two switching elements. In addition, a capacitor is provided in parallel with the plurality of semiconductor modules. The semiconductor modules are provided for each phase. In addition, the positive terminal of the capacitor and the positive terminals of the plurality of semiconductor modules are electrically connected by a bus bar (hereinafter referred to as a positive-side bus bar). In addition, the negative terminals of two capacitors and the negative terminals of the plurality of semiconductor modules are electrically connected by a bus bar (hereinafter referred to as a negative-side bus bar). In Japanese Patent Application Publication No. 2016-213945, both the positive-side bus bar and the negative-side bus bar are composed of a copper plate having a substantially U-shaped shape. In addition, the positive-side bus bar and the negative-side bus bar are integrally provided in a manner shared by the semiconductor modules of each phase, respectively.

[0004] In the conventional power conversion device as described in Japanese Patent Application Publication No. 2016-213945, sometimes the semiconductor modules of each phase are provided in parallel to increase the capacity of the power conversion device. In addition, the number of the semiconductor modules provided in parallel increases in accordance with the capacity of the power conversion device. In this case, when the positive-side bus bar and the negative-side bus bar composed of a copper plate are integrally provided in a manner shared by the semiconductor modules of each phase, respectively, as described in Japanese Patent Application Publication No. 2016-213945, the positive-side bus bar and the negative-side bus bar are upsized, and the weight is increased. Therefore, there is a problem that the workability in assembling the power conversion device deteriorates. SUMMARY

[0005] The present application has been achieved in order to solve the problems as described above, and an object of the present application is to provide a power conversion device capable of suppressing deterioration of workability in assembly even when the number of semiconductor modules increases.

[0006] To achieve the above object, a power conversion device based on one aspect of the present application includes: a semiconductor module that houses semiconductor elements inside, a plurality of semiconductor elements being provided for each phase; a capacitor that is electrically connected to the semiconductor module; a positive electrode conductor that is electrically connected to a positive electrode terminal of the capacitor and a positive electrode terminal of the semiconductor module; and a negative electrode conductor that is electrically connected to a negative electrode terminal of the capacitor and a negative electrode terminal of the semiconductor module, wherein at least one of the positive electrode conductor and the negative electrode conductor is integrally configured in a manner shared by at least a plurality of phases of the semiconductor modules of each phase, and is composed of aluminum.

[0007] In the power conversion device based on one aspect of the present application, as described above, at least one of the positive electrode conductor and the negative electrode conductor is integrally configured in a manner shared by at least a plurality of phases of the semiconductor modules of each phase, and is composed of aluminum. Thereby, since the specific gravity of aluminum is smaller than that of copper, at least one of the positive electrode conductor and the negative electrode conductor is lightened. As a result, even in a case where the positive electrode conductor and the negative electrode conductor are enlarged in size due to an increase in the number of the semiconductor modules, an increase in the weight of at least one of the positive electrode conductor and the negative electrode conductor is suppressed. Therefore, even in a case where the number of the semiconductor modules is increased, deterioration in workability at the time of assembly can be suppressed. Further, since at least one of the positive electrode conductor and the negative electrode conductor is composed of aluminum, the power conversion device can be lightened.

[0008] Further, since at least one of the positive electrode conductor and the negative electrode conductor is integrally configured in a manner shared by at least a plurality of phases of the semiconductor modules of each phase, unlike a case where at least one of the positive electrode conductor and the negative electrode conductor is separately provided for each phase, an increase in the number of components can be suppressed.

[0009] In the power conversion device based on one aspect described above, it is preferable that both the positive electrode conductor and the negative electrode conductor are integrally configured in a manner shared by the semiconductor modules of each phase, and are composed of aluminum. By being configured thus, both the positive electrode conductor and the negative electrode conductor are composed of aluminum, and therefore the total weight of the positive electrode conductor and the negative electrode conductor can be lightened. As a result, deterioration in workability at the time of assembly can be further suppressed. Further, the power conversion device can be further lightened.

[0010] In the power conversion device based on one aspect described above, it is preferable that both the positive electrode conductor and the negative electrode conductor have a flat plate shape, and the flat plate-shaped positive electrode conductor and the flat plate-shaped negative electrode conductor are laminated. By being configured thus, the parasitic inductance of the positive electrode conductor and the negative electrode conductor can be reduced by making the direction in which current flows through the positive electrode conductor and the direction in which current flows through the negative electrode conductor be opposite directions.

[0011] In the power conversion device based on one of the above aspects, it is preferable to further include an output conductor electrically connected to the output terminal of the semiconductor module, the output conductor has a flat shape and is composed of aluminum, the output conductor is provided separately for each phase, and the positive electrode conductor having a flat shape, the negative electrode conductor having a flat shape, and the output conductor provided separately for each phase are laminated. By so configuring, in addition to at least one of the positive electrode conductor and the negative electrode conductor being composed of aluminum, the output conductor is also composed of aluminum, so that deterioration of workability at the time of assembly can be further suppressed. In addition, the power conversion device can be further lightened.

[0012] In the power conversion device based on one of the above aspects, it is preferable to further include a fuse shared by the semiconductor modules of each phase, the fuse being provided between the positive electrode conductor and the capacitor. By so configuring, compared to a case where the fuse is provided separately for each phase, the current flowing through the fuse can be reduced. As a result, the fuse can be miniaturized.

[0013] In the power conversion device based on one of the above aspects, it is preferable to further include a capacitor conductor having a flat shape electrically connected to the positive electrode terminal of the capacitor, and the fuse is connected to the positive electrode conductor and the capacitor conductor. By so configuring, the fuse shared by the semiconductor modules of each phase can be easily connected to the capacitor conductor and the positive electrode conductor.

[0014] According to the present application, as described above, even in a case where the number of semiconductor modules increases, deterioration of workability at the time of assembly can be suppressed. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a circuit diagram of a power conversion device based on the present embodiment.

[0016] Figure 2 is a circuit diagram of a semiconductor module of a power conversion device based on the present embodiment.

[0017] Figure 3 is a perspective view of a semiconductor module of a power conversion device based on the present embodiment.

[0018] Figure 4 is a perspective view of a semiconductor module and a laminated bus bar based on the present embodiment.

[0019] Figure 5 is an exploded perspective view of a laminated bus bar based on the present embodiment.

[0020] Figure 6 is a plan view of a laminated bus bar, a fuse, and a capacitor based on the present embodiment. DETAILED DESCRIPTION

[0021] Next, an embodiment in which the present application is embodied will be described below based on the drawings.

[0022] The structure of the power conversion device 100 based on the present embodiment will be described with reference to Figures 1-6

[0023] As shown in Figure 1 , the power conversion device 100 is provided with a rectifying section 10. The rectifying section 10 is input with alternating current power. The rectifying section 10 converts the input alternating current power into direct current power.

[0024] The power conversion device 100 is provided with a capacitor C. The capacitor C is configured to smooth the direct current power converted by the rectifying section 10. In addition, the capacitor C is provided between the rectifying section 10 and a semiconductor module 20. A plurality of capacitors C is provided. Among the plurality of capacitors C, every two capacitors C are connected in series to each other, and the two capacitors C connected in series are connected in parallel to each other between other two capacitors C connected in series.

[0025] The power conversion device 100 is provided with a resistor R. A plurality of resistors R is provided. Among the plurality of resistors R, every two resistors R are connected in series to each other, and the two resistors R connected in series are connected in parallel to each other between other two resistors R connected in series. In addition, the resistors R connected in series are connected in parallel to the capacitors C connected in series.

[0026] As shown in Figure 2 and Figure 3 , the power conversion device 100 is provided with the semiconductor module 20. The semiconductor module 20 internally houses switching elements Q1 and Q2, and a plurality of semiconductor modules 20 is provided for each phase (U phase, V phase, and W phase). For example, eight semiconductor modules 20 are provided for each phase.

[0027] In addition, the semiconductor module 20 includes a C terminal 21 (a collector terminal), an E terminal 22 (an emitter terminal), an output terminal 23, and a gate terminal 24. In addition, a capacitor C1 and a capacitor C2 are provided in parallel to the semiconductor module 20. Furthermore, the C terminal 21 and the E terminal 22 are examples of the "positive terminal" and the "negative terminal" of the present application, respectively.

[0028] In addition, the C terminal 21 of the semiconductor module 20 is electrically connected to a positive terminal Cp of the capacitor C (refer to Figure 1 ). In addition, the E terminal 22 of the semiconductor module 20 is electrically connected to a negative terminal Cn of the capacitor C (refer to Figure 1 ).

[0029] In addition, as shown in Figure 4 ​As shown, the semiconductor modules 20 (24 semiconductor modules 20) of each phase (U phase, V phase, and W phase) are configured in a matrix shape of 4 in the X direction and 6 in the Y direction (4 rows x 6 columns). In addition, the 24 semiconductor modules 20 are arranged on the surface of a heat sink, not shown.

[0030] Here, in the present embodiment, as shown in FIG. 1, the power conversion device 100 is provided with a positive conductor 30 (bus bar) that is electrically connected to the positive terminal Cp of the capacitor C and the C terminal 21 of the semiconductor module 20, and a negative conductor 40 (bus bar) that is electrically connected to the negative terminal Cn of the capacitor C and the E terminal 22 of the semiconductor module 20. Furthermore, at least one of the positive conductor 30 and the negative conductor 40 (both in the present embodiment) is integrally configured in a manner shared by the semiconductor modules 20 of at least a plurality of phases (all phases in the present embodiment) of the semiconductor modules 20 of each phase, and is composed of aluminum. Figure 5

[0031] The specific gravity of copper is 3.32 times the specific gravity of aluminum. In addition, the electrical resistance value of copper is 0.63 times the electrical resistance value of aluminum. Thus, in the case where the positive conductor 30 (negative conductor 40) is formed using aluminum in a manner that enables the flow of a prescribed amount of electric current, the weight of the positive conductor 30 (negative conductor 40) is about half compared to the case where the positive conductor 30 (negative conductor 40) is formed using copper in a manner that enables the flow of a prescribed amount of electric current.

[0032] In addition, the positive conductor 30 has a flat plate shape. In addition, the positive conductor 30 has a substantially rectangular shape. Furthermore, the positive conductor 30 is disposed so as to cover the semiconductor modules 20 (24 semiconductor modules 20) of the U phase, V phase, and W phase. In addition, one positive conductor 30 is provided for the 24 semiconductor modules 20.

[0033] In addition, the positive conductor 30 is provided with a connection terminal 31 that is connected to the C terminal 21 of the 24 semiconductor modules 20. The connection terminal 31 is provided at a position of the positive conductor 30 that corresponds to the C terminal 21 of the 24 semiconductor modules 20 (directly above the C terminal 21 of the semiconductor module 20).

[0034] In addition, the positive conductor 30 is provided with a circular hole portion 32 at a position that corresponds to the E terminal 22 and the output terminal 23, and a quadrangular hole portion 33 at a position that corresponds to the gate terminal 24. The E terminal 22 and the output terminal 23 are exposed on the Z1 direction side by the hole portion 32. The gate terminal 24 is exposed on the Z1 direction side by the hole portion 33.

[0035] In addition, the end portion 34 of the positive conductor 30 on the X1 direction side has a stepped shape. That is, the positive conductor 30 is configured to extend toward the Z1 direction side after extending toward the X1 direction side, and then extend toward the X1 direction side.​

[0036] Further, the negative conductor 40 has a flat plate shape. Further, the negative conductor 40 has a substantially rectangular shape. Moreover, the negative conductor 40 is provided so as to cover the semiconductor modules 20 (24 semiconductor modules 20) of the U phase, the V phase, and the W phase. Further, one negative conductor 40 is provided for the 24 semiconductor modules 20.

[0037] Further, the negative conductor 40 is provided with a connection terminal 41 that is connected to the E terminal 22 of the 24 semiconductor modules 20. The connection terminal 41 is provided at a position of the negative conductor 40 that corresponds to the E terminal 22 of the 24 semiconductor modules 20 (directly above the E terminal 22 of the semiconductor module 20).

[0038] Further, the negative conductor 40 is provided with a circular hole portion 42 at a position that corresponds to the C terminal 21 and the output terminal 23, and is provided with a quadrangular hole portion 43 at a position that corresponds to the gate terminal 24. The C terminal 21 and the output terminal 23 are exposed on the Zl direction side by the hole portion 42. The gate terminal 24 is exposed on the Zl direction side by the hole portion 43.

[0039] Further, in the present embodiment, the positive conductor 30 having a flat plate shape is laminated with the negative conductor 40 having a flat plate shape. Further, the insulating paper 50 is arranged between the positive conductor 30 and the negative conductor 40. The positive conductor 30 and the negative conductor 40 are insulated by the insulating paper 50. Furthermore, in the present embodiment, the positive conductor 30 is provided with a connection terminal 31 that is connected to the C terminal 21 of the 24 semiconductor modules 20. Figure 5 The state in which the insulating paper 50 is arranged on the negative conductor 40 is illustrated in FIG. 6. The insulating paper 50 is provided with a hole portion 51 that exposes the connection terminal 41, the C terminal 21, the output terminal 23, and the gate terminal 24.

[0040] Further, in the present embodiment, the power conversion device 100 is provided with an output conductor 60 (bus bar) that is electrically connected to the output terminal 23 of the semiconductor module 20. The output conductor 60 has a flat plate shape, and is composed of aluminum. Further, the output conductor 60 (the output conductor 60a, the output conductor 60b, and the output conductor 60c) is separately provided for each phase.

[0041] That is, one output conductor 60a of the U phase is provided for the 8 semiconductor modules 20 of the U phase. The output conductor 60a is provided so as to cover the 8 semiconductor modules 20.

[0042] Further, the output conductor 60a is provided with a connection terminal 61 that is connected to the output terminal 23 of the 24 semiconductor modules 20. The connection terminal 61 is provided at a position of the output conductor 60a that corresponds to the output terminal 23 of the 24 semiconductor modules 20 (directly above the output terminal 23 of the semiconductor module 20).

[0043] Additionally, on the output conductor 60a, a hole 62, which is approximately T-shaped when viewed from the Z direction, is provided at a position corresponding to the C terminal 21, E terminal 22, and gate terminal 24 of the semiconductor module 20. The C terminal 21, E terminal 22, and gate terminal 24 are exposed from the hole 62 on the Z1 direction side.

[0044] Furthermore, the X2-direction side end 63 of the output conductor 60a has a stepped shape. That is, the output conductor 60a is configured to extend in the X2-direction side, then in the Z1-direction side, and then in the X2-direction side again.

[0045] Furthermore, the structures of output conductors 60b and 60c are the same as those of output conductor 60a.

[0046] Furthermore, in this embodiment, a flat-plate positive conductor 30, a flat-plate negative conductor 40, and an output conductor 60 individually provided for each phase are stacked. The stacked positive conductor 30, negative conductor 40, and output conductor 60 constitute a laminated busbar 70 (see reference). Figure 4 Furthermore, the negative conductor 40, the positive conductor 30, and the output conductor 60 are stacked in this order from the Z2 direction side to the Z1 direction side. In addition, insulating paper 50 is provided between the negative conductor 40 and the positive conductor 30, and between the positive conductor 30 and the output conductor 60.

[0047] In addition, in this embodiment, such as Figure 6 As shown, the power conversion device 100 includes a fuse 80 shared by the semiconductor modules 20 of each phase, which is disposed between the positive conductor 30 and the capacitor C. Multiple fuses 80 (three in this embodiment) are arranged in parallel. Furthermore, the fuse 80 is connected to a flat conductor 90 (busbar) and the positive conductor 30, which is electrically connected to multiple capacitors C and multiple resistors R. The conductor 90 is made of aluminum. The conductor 90 is shared by multiple capacitors C and multiple resistors R. Furthermore, the conductor 90 is an example of a "capacitor conductor" in this invention.

[0048] Furthermore, compared to the case where fuses 80 are provided separately for each phase of the semiconductor module 20, the current flowing through a single fuse 80 is 0.5 times that when fuses 80 are provided in a manner shared by all phases of the semiconductor module 20.

[0049] [Effects of this implementation method]

[0050] In this embodiment, the following effects can be achieved.

[0051] In the present embodiment, as described above, at least one of the positive electrode conductor 30 and the negative electrode conductor 40 (both in the present embodiment) is integrally configured in a manner shared by the semiconductor modules 20 of at least a plurality of phases (all phases in the present embodiment) of the semiconductor modules 20 of each phase, and is composed of aluminum. Thereby, since the specific gravity of aluminum is smaller than that of copper, at least one of the positive electrode conductor 30 and the negative electrode conductor 40 is lightweighted. As a result, even in a case where the positive electrode conductor 30 and the negative electrode conductor 40 are upsized due to an increase in the number of the semiconductor modules 20, an increase in the weight of at least one of the positive electrode conductor 30 and the negative electrode conductor 40 is suppressed. Therefore, even in a case where the number of the semiconductor modules 20 is increased, deterioration in workability at the time of assembly can be suppressed. Further, since at least one of the positive electrode conductor 30 and the negative electrode conductor 40 is composed of aluminum, the power conversion device 100 can be lightweighted.

[0052] Further, at least one of the positive electrode conductor 30 and the negative electrode conductor 40 (both in the present embodiment) is integrally configured in a manner shared by the semiconductor modules 20 of at least a plurality of phases (all phases in the present embodiment) of the semiconductor modules 20 of each phase, and therefore, unlike a case where at least one of the positive electrode conductor 30 and the negative electrode conductor 40 is provided separately for each phase, an increase in the number of components can be suppressed.

[0053] Further, in the present embodiment, as described above, both of the positive electrode conductor 30 and the negative electrode conductor 40 are integrally configured in a manner shared by the semiconductor modules 20 of each phase, and are composed of aluminum. Thereby, since both of the positive electrode conductor 30 and the negative electrode conductor 40 are composed of aluminum, the total weight of the positive electrode conductor 30 and the negative electrode conductor 40 can be lightweighted. As a result, deterioration in workability at the time of assembly can be further suppressed. Further, the power conversion device 100 can be further lightweighted.

[0054] Further, in the present embodiment, as described above, both of the positive electrode conductor 30 and the negative electrode conductor 40 have a flat plate shape, and the flat plate-shaped positive electrode conductor 30 and the flat plate-shaped negative electrode conductor 40 are laminated. Thereby, by making the direction in which the current flows through the positive electrode conductor 30 and the direction in which the current flows through the negative electrode conductor 40 be opposite directions, the stray inductance of the positive electrode conductor 30 and the negative electrode conductor 40 can be reduced.

[0055] Further, in the present embodiment, as described above, the output conductor 60 electrically connected to the output terminal 23 of the semiconductor module 20 is further provided, the output conductor 60 has a flat plate shape, and is composed of aluminum, and the output conductor 60 is provided separately for each phase, the positive electrode conductor 30 of the flat plate shape, the negative electrode conductor 40 of the flat plate shape, and the output conductor 60 provided separately for each phase are laminated. Thus, since at least one of the positive electrode conductor 30 and the negative electrode conductor 40 is composed of aluminum, and the output conductor 60 is also composed of aluminum, it is possible to further suppress deterioration of workability at the time of assembly. Further, it is possible to further reduce the weight of the power conversion device 100.

[0056] Further, in the present embodiment, as described above, the fuse 80 shared by the semiconductor modules 20 of each phase is further provided, the fuse 80 is provided between the positive electrode conductor 30 and the capacitor C. Thus, compared to a case where the fuse 80 is provided separately for each phase, it is possible to reduce the current flowing through the fuse 80. As a result, it is possible to downsize the fuse 80.

[0057] Further, in the present embodiment, as described above, the fuse 80 is connected to the positive electrode conductor 30 and the conductor 90. Thus, it is possible to easily connect the fuse 80 shared by the semiconductor modules 20 of each phase to the conductor 90 and the positive electrode conductor 30.

[0058] [Modified Example]

[0059] Furthermore, it should be understood that all aspects of the embodiments disclosed herein are merely illustrative and not restrictive. The scope of the application is not shown by the above description of the embodiments but by the claims, and the scope of the application includes all modifications (modified examples) within the meaning and range equivalent to the claims.

[0060] For example, in the above-described embodiment, an example in which both the positive electrode conductor 30 and the negative electrode conductor 40 are composed of aluminum is shown, but the present application is not limited thereto. For example, one of the positive electrode conductor 30 and the negative electrode conductor 40 can be composed of aluminum, and the other can be composed of copper.

[0061] Further, in the above-described embodiment, an example in which the positive electrode conductor 30 (the negative electrode conductor 40) is integrally configured in a manner shared by the semiconductor modules 20 of all phases of the U phase, the V phase, and the W phase is shown, but the present application is not limited thereto. For example, it can be configured that the positive electrode conductors (negative electrode conductors) of the U phase and the V phase are integrally provided in a shared manner, and the positive electrode conductor (negative electrode conductor) of the W phase is provided separately from the positive electrode conductors (negative electrode conductors) of the U phase and the V phase.

[0062] Further, in the above-described embodiment, an example in which both the positive electrode conductor 30 and the negative electrode conductor 40 are integrally configured in a manner shared by the semiconductor modules 20 of all of the U-phase, V-phase, and W-phase has been shown, but the present application is not limited thereto. For example, one of the positive electrode conductor 30 and the negative electrode conductor 40 can be integrally configured in a manner shared by the semiconductor modules 20 of the U-phase, V-phase, and W-phase, and the other of the positive electrode conductor 30 and the negative electrode conductor 40 can be configured in a manner independent for each phase.

[0063] Further, in the above-described embodiment, an example in which the laminated bus bar 70 is configured by the positive electrode conductor 30, the negative electrode conductor 40, and the output conductor 60 has been shown, but the present application is not limited thereto. For example, the positive electrode conductor 30, the negative electrode conductor 40, and the output conductor 60 can be arranged at a distance corresponding to the separation and insulation distance from each other (may be configured in a manner not subjected to lamination processing).

[0064] Further, in the above-described embodiment, an example in which the positive electrode conductor 30, the negative electrode conductor 40, and the output conductor 60 have a flat plate shape has been shown, but the present application is not limited thereto. For example, the positive electrode conductor 30, the negative electrode conductor 40, and the output conductor 60 can have a shape other than the flat plate shape.

[0065] Further, in the above-described embodiment, an example in which a plurality of the fuses 80 are provided in a parallel manner has been shown, but the present application is not limited thereto. For example, one fuse 80 having a larger capacity can be provided.

Claims

1. A power conversion device comprising: semiconductor modules each of which houses therein a semiconductor element, a plurality of the semiconductor modules being provided for each phase; a plurality of capacitors electrically connected to the semiconductor modules; a positive electrode conductor in a flat plate shape electrically connected to positive electrode terminals of the capacitors and positive electrode terminals of the semiconductor modules; a negative electrode conductor in a flat plate shape electrically connected to negative electrode terminals of the capacitors and negative electrode terminals of the semiconductor modules; a plurality of fuses common to the semiconductor modules of the respective phases, the plurality of fuses being provided between the positive electrode conductor and the plurality of capacitors; and a capacitor conductor in a flat plate shape electrically connected to the plurality of fuses and the positive electrode terminals of the plurality of capacitors, the capacitor conductor being composed of aluminum, the capacitor conductor being provided in a manner common to the plurality of fuses and the plurality of capacitors, wherein the positive electrode conductor and the negative electrode conductor are integrally composed in a manner common to the semiconductor modules of the respective phases and are composed of aluminum.

2. The power conversion device according to claim 1, wherein the positive electrode conductor in the flat plate shape and the negative electrode conductor in the flat plate shape are laminated.

3. The power conversion device according to claim 1 or 2, further comprising an output conductor electrically connected to output terminals of the semiconductor modules, wherein the output conductor has a flat plate shape and is composed of the aluminum, the output conductor being provided separately for each phase, and wherein the positive electrode conductor in the flat plate shape, the negative electrode conductor in the flat plate shape, and the output conductor provided separately for each phase are laminated. ​ ​ ​ ​ wherein ​ ​ ​ ​ ​ ​ ​

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