JP6493171B2 - Power converter - Google Patents

Description

  The present invention relates to a power conversion device including a switching element.

  For example, a power conversion device such as an inverter mounted on an electric vehicle, a hybrid vehicle, or the like is configured to perform power conversion between DC power and AC power by turning on and off a plurality of switching elements. In the switching circuit in such a power converter, a surge voltage is generated with the on / off operation of the switching element. When a large surge voltage is applied to the switching element, it can affect the operation of the switching element.

  Therefore, the power conversion device described in Patent Document 1 connects a portion between the positive terminal and the positive switching element and a portion between the negative terminal and the negative switching element via a snubber capacitor. Yes. As a result, the snubber capacitor absorbs the surge voltage generated in the switching circuit, and attempts to suppress the application of a large surge voltage to the switching element.

JP 2014-187874 A

  However, the power converter cannot reduce the parasitic inductance in the current path of the alternating current flowing through the positive side switching element, the output terminal, and the negative side switching element. Therefore, there is a problem that it is difficult to reduce the surge voltage due to the parasitic inductance.

  This invention is made | formed in view of this subject, and aims to provide the power converter device which can suppress a parasitic inductance effectively.

One aspect of the present invention includes an output terminal (2) electrically connected to an AC load (10),
A positive electrode side connection portion (3) and a negative electrode side connection portion (4) branched from the output terminal via a branch portion (12);
A positive side switching element (51) connected to an end of the positive side connection part opposite to the output terminal;
A negative electrode side switching element (52) connected to an end of the negative electrode side connection portion opposite to the output terminal;
A positive terminal (61) electrically connected to the positive-side switching element;
A negative terminal (62) electrically connected to the negative side switching element;
An electrical connection is made between a portion on the positive electrode side switching element side with respect to the branch portion in the positive electrode side connection portion and a portion on the negative electrode side switching element side with respect to the branch portion in the negative electrode side connection portion. a bypass conductor (11), was closed,
In the longitudinal direction (Y) orthogonal to the alignment direction (X) of the positive electrode side switching element and the negative electrode side switching element, the positive electrode terminal, the negative electrode terminal, and the output terminal are the positive electrode side switching element and the negative electrode, respectively. Are arranged on opposite sides of the side switching element,
The bypass conductor is disposed between the positive electrode side switching element and the negative electrode side switching element when viewed from a height direction (Z) orthogonal to both the alignment direction and the vertical direction,
The positive electrode side switching element, the bypass conductor, and the negative electrode side switching element are in the power conversion device (1) arranged so as to be aligned in the alignment direction .

  The power converter has a bypass conductor at the position. Thereby, the electric current path of the alternating current which flows through the positive electrode side switching element and the negative electrode side switching element can be shortened. Therefore, the parasitic inductance in the current path can be suppressed. As a result, the surge voltage applied to the positive side switching element and the negative side switching element can be suppressed.

As described above, according to this aspect, it is possible to provide a power conversion device that can effectively suppress parasitic inductance.
In addition, the code | symbol in the parenthesis described in the means to solve a claim and a subject shows the correspondence with the specific means as described in embodiment mentioned later, and limits the technical scope of this invention. Not a thing

FIG. 3 is a top view of the semiconductor module according to the first embodiment. The II-II sectional view taken on the line of FIG. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 1. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 1. 1 is a perspective view of a semiconductor module in Embodiment 1. FIG. The circuit diagram of the power converter device in Embodiment 1. FIG. FIG. 3 is an explanatory diagram of a current path passing through a positive electrode side switching element and a negative electrode side switching element in the first embodiment. Explanatory drawing of the electric current path which passes along the positive electrode side switching element and the negative electrode side switching element in the semiconductor module which does not have a bypass conductor The front view of the semiconductor module in Embodiment 2. FIG. FIG. 10 is a cross-sectional view taken along line AA in FIG. 9. Explanatory drawing of the current pathway which passes in the positive electrode side switching element and negative electrode side switching element in Embodiment 2. FIG. Explanatory drawing of the current pathway which passes along the positive electrode side switching element and the negative electrode side switching element in the semiconductor module which does not have a bypass conductor.

(Embodiment 1)
An embodiment according to a power conversion device will be described with reference to FIGS.
As shown in FIGS. 1 and 5, the power conversion device 1 of the present embodiment includes an output terminal 2, a positive electrode side connection portion 3, a negative electrode side connection portion 4, a positive electrode side switching element 51, a negative electrode side switching element 52, and a positive electrode terminal 61. And a negative electrode terminal 62 and a bypass conductor 11. As shown in FIG. 6, the output terminal 2 is electrically connected to the AC load 10. As shown in FIGS. 1 and 5, the positive electrode side connection portion 3 and the negative electrode side connection portion 4 are branched from the output terminal 2 via the branch portion 12. As shown in FIGS. 1, 3, and 5, the positive side switching element 51 is connected to the end of the positive side connection portion 3 opposite to the output terminal 2. As shown in FIGS. 1, 4, and 5, the negative electrode side switching element 52 is connected to the end of the negative electrode side connection portion 4 opposite to the output terminal 2.

  As shown in FIG. 6, the positive terminal 61 is electrically connected to the positive switching element 51. The negative terminal 62 is electrically connected to the negative side switching element 52. As shown in FIGS. 1, 5, and 6, the bypass conductor 11 includes a portion on the positive electrode side switching element 51 side with respect to the branch portion 12 in the positive electrode side connection portion 3 and a negative electrode on the negative electrode side with respect to the branch portion 12 in the negative electrode side connection portion 4. A portion on the side switching element 52 side is electrically connected.

  As shown in FIGS. 1 and 3 to 5, the positive electrode terminal 61, the negative electrode terminal 62, and the output terminal 2 are positive in the longitudinal direction Y orthogonal to the arrangement direction of the positive electrode side switching element 51 and the negative electrode side switching element 52. The side switching element 51 and the negative side switching element 52 are disposed on opposite sides of each other. As shown in FIG. 1, the bypass conductor 11 is arranged between the positive electrode side switching element 51 and the negative electrode side switching element 52 when viewed from a direction orthogonal to both the arrangement direction and the vertical direction Y. In the present embodiment, the direction orthogonal to both the arrangement direction and the vertical direction Y is the same as the thickness direction of the positive electrode side switching element 51 and the negative electrode side switching element 52. The bypass conductor 11 is positioned inward of the positive electrode side switching element 51 and the negative electrode side switching element 52 in the longitudinal direction Y.

  In the following, the arrangement direction of the positive electrode side switching element 51 and the negative electrode side switching element 52 is referred to as a lateral direction X. A direction orthogonal to both the horizontal direction X and the vertical direction Y is referred to as a height direction Z. The height direction Z is a convenient expression and is not particularly limited to the vertical direction.

  The power converter 1 of this embodiment is an inverter apparatus which converts direct-current power into three-phase alternating current power, as shown in FIG. Specifically, the power conversion device 1 is configured to perform power conversion between the DC power supply 100 and the AC load 10. And the power converter device 1 of this embodiment is provided with the positive electrode side switching element 51 and the negative electrode side switching element 52 3 each. The pair of positive electrode side switching elements 51 and negative electrode side switching elements 52 are molded by a mold resin 70 having electrical insulation to constitute the semiconductor module 7. That is, the power conversion device 1 of the present embodiment has three semiconductor modules 7. The output terminals 2 of the three semiconductor modules 7 are connected to the U phase, V phase, and W phase of the AC load 10, respectively.

  The three semiconductor modules 7 all have the same structure. In the following description, the semiconductor module 7 will be mainly described. 1 and 6, the mold resin 70 is represented by a two-dot chain line. Further, in the drawings other than FIGS. 1 and 6, the illustration of the mold resin 70 is omitted as appropriate.

  As shown in FIG. 2, the semiconductor module 7 includes a base plate 71 having a main surface directed in the height direction Z. The positive electrode side switching element 51 and the negative electrode side switching element 52 are laminated together with other components on one surface of the base plate 71. In the following, in the height direction Z, the side of the base plate 71 on which the positive electrode side switching element 51 and the negative electrode side switching element 52 are arranged is referred to as the upper side, and the opposite side is referred to as the lower side. Moreover, in drawings other than FIG. 2, illustration of a base plate is abbreviate | omitted suitably.

  As shown in FIGS. 2 to 4, a copper pattern layer 72 and an insulating layer 73 are disposed on the upper surface of the base plate 71. A copper pattern layer 741, a positive electrode side switching element 51, and a bus bar 771 are sequentially stacked on a part of the upper surface of the insulating layer 73. In addition, a copper pattern layer 742, a negative electrode side switching element 52, and a bus bar 772 are sequentially stacked on another part of the upper surface of the insulating layer 73. The insulating layer 73 is a layer having electrical insulation, and the bus bars 771 and 772 are layers having conductivity and thermal conductivity.

  The positive electrode side switching element 51 and the negative electrode side switching element 52 are arranged adjacent to each other in the lateral direction X. Each switching element is made of an IGBT (that is, an insulated gate bipolar transistor). Each switching element is connected in reverse parallel with an FWD (ie, flywheel diode). In the drawings other than the circuit diagram, the FWD is omitted as appropriate.

  The positive side switching element 51 and the negative side switching element 52 have collectors 51c and 52c on their lower surfaces, and have emitters 51e and 52e on their upper surfaces. As shown in FIG. 3, the collector 51 c of the positive electrode side switching element 51 is connected to the positive electrode terminal 61 through the copper pattern layer 741. As shown in FIGS. 2 and 4, the emitter 52 e on the upper surface of the negative electrode side switching element 52 is connected to the negative electrode terminal 62 via the bus bar 772.

  As shown in FIGS. 1 and 5, the positive electrode terminal 61 and the negative electrode terminal 62 are arranged on the same side in the vertical direction Y with respect to the positive electrode side switching element 51 and the negative electrode side switching element 52. As shown in FIGS. 3 and 4, the positive electrode terminal 61 and the negative electrode terminal 62 are plate-like metals, and as shown in FIG. 1, they are arranged side by side in the horizontal direction X with the main surface facing the height direction Z. Has been. The positive terminal 61 and the negative terminal 62 are partially exposed from the mold resin 70, respectively. Further, the positive electrode terminal 61 and the negative electrode terminal 62 have connection portions 611 and 621 with conductors connected to the respective terminals on a part of the tip side exposed from the mold resin 70.

  As shown in FIG. 3, the emitter 51 e on the upper surface of the positive electrode side switching element 51 is connected to the output terminal 2 via the positive electrode side connection portion 3. In the present embodiment, the positive electrode side connecting portion 3 is constituted by a bus bar 771 and a bus bar 781. Further, as shown in FIG. 4, the collector 52 c on the lower surface of the negative electrode side switching element 52 is connected to the output terminal 2 via the negative electrode side connection portion 4. In the present embodiment, the negative electrode side connection portion 4 includes a copper pattern layer 742, a bus bar 782, and a bus bar 752. The bus bar 752 is a conductor disposed between the copper pattern layer 742 and the bus bar 782 in the height direction Z.

  As shown in FIG. 2, the positive electrode side connecting portion 3 and the negative electrode side connecting portion 4 are arranged side by side in the lateral direction X. As shown in FIG. 1, when viewed from the height direction Z, the positive electrode terminal 61, the positive electrode side switching element 51, and the positive electrode side connection portion 3 are arranged on a straight line in the vertical direction Y. Further, when viewed from the height direction Z, the negative electrode terminal 62, the negative electrode side switching element 52, and the negative electrode side connection portion 4 are arranged on a straight line in the vertical direction Y.

  As shown in FIGS. 3 and 4, the positive electrode side connecting portion 3 and the negative electrode side connecting portion 4 are connected to the output terminal 2. Thereby, as shown in FIG. 6, the positive electrode side switching element 51 and the negative electrode side switching element 52 are electrically connected via the positive electrode side connection portion 3, the output terminal 2, and the negative electrode side connection portion 4. .

  As shown in FIGS. 3 to 5, the output terminal 2 includes a wide portion 21, a connecting portion 22, and a protruding portion 23. The wide part 21 has a height direction Z in the thickness direction and a rectangular plate shape that is long in the lateral direction X. Then, the positive electrode side connecting portion 3 and the negative electrode side connecting portion 4 are connected to portions on both sides in the lateral direction X on the upper surface of the wide portion 21. That is, in the present embodiment, the positive electrode side connection portion 3 and the negative electrode side connection portion 4 are branched from the output terminal 2 via the branch portion 12 constituted by a part of the wide portion 21.

  The connecting portion 22 is formed upward from the end of the wide portion 21 opposite to the protruding side of the positive electrode terminal 61 and the negative electrode terminal 62. Moreover, the connection part 22 is formed toward the upper side from the center part of the horizontal direction X in the wide part 21, The vertical direction Y is the thickness direction. And the protrusion part 23 is formed toward the opposite side to the protrusion side of the positive electrode terminal 61 and the negative electrode terminal 62 from the upper end of the connection part 22. As shown in FIG. As shown in FIG. 1, the protruding portion 23 is partially exposed from the mold resin 70. Further, the output terminal 2 has a connection portion 231 with a conductor to be connected to a part of the tip side exposed from the mold resin 70.

  As shown in FIGS. 1, 2, and 5, in this embodiment, the bus bar 781 of the positive electrode side connection portion 3 and the copper pattern layer 742 of the negative electrode side connection portion 4 are connected by the bypass conductor 11. Thereby, the positive electrode side switching element 51 and the negative electrode side switching element 52 are connected by both the current path via the bypass conductor 11 and the current path via the branch part 12. The current path through the bypass conductor 11 is a current path including the bus bar 771, the bus bar 781, the bypass conductor 11, and the copper pattern layer 742. The current path through the branching portion 12 is a current path including the bus bar 771, the bus bar 781, the branching portion 12, the bus bar 782, the bus bar 752, and the copper pattern layer 742. The current path connecting the positive side switching element 51 and the negative side switching element 52 is shorter in the current path via the bypass conductor 11 than in the current path via the output terminal 2.

  The bypass conductor 11 is a wire. That is, the bypass conductor 11 is a bonding wire bonded to the bus bar 781 and the copper pattern layer 742. The bypass conductor 11 may be a ribbon. The ribbon has a long flat shape and is a flexible conductor. The bypass conductor 11 may be a bus bar. The bus bar is a plate-like conductor having a thickness larger than that of the ribbon.

Next, the effect of this embodiment is demonstrated.
The power converter 1 has the bypass conductor 11 in said position. Thereby, the current path of the alternating current flowing through the positive electrode side switching element 51 and the negative electrode side switching element 52 can be shortened. That is, as shown in FIG. 7, the current path 81 includes a positive electrode terminal 61, a positive electrode side switching element 51, a part of the positive electrode side connection part 3, a bypass conductor 11, a part of the negative electrode side connection part 4, and a negative electrode side switching element 52. And the negative electrode terminal 62. On the other hand, as shown in FIG. 8, when the bypass conductor 11 is not provided, the current path 82 of the alternating current flowing through the positive electrode side switching element 51 and the negative electrode side switching element 52 is the positive electrode terminal 61, the positive electrode side switching element 51, and the positive electrode. The side connection part 3, the output terminal 2, the negative electrode side connection part 4, and the negative electrode terminal 62 are passed. As shown in FIGS. 7 and 8, the current path 81 passing through the bypass conductor 11 is compared with the current path 82 passing through the output terminal 2, the region from the bypass conductor 11 to the output terminal 2 in the positive electrode side connection portion 3, the output terminal 2. And the path | route can be shortened because it does not pass through the area | region from the output terminal 2 in the negative electrode side connection part 4 to the bypass conductor 11. FIG. Therefore, the parasitic inductance in the current path 81 of the alternating current passing through the positive electrode side switching element 51 and the negative electrode side switching element 52 can be suppressed. As a result, the surge voltage applied to the positive electrode side switching element 51 and the negative electrode side switching element 52 can be suppressed.

  Further, the bypass conductor 11 is disposed between the positive electrode side switching element 51 and the negative electrode side switching element 52 when viewed from the height direction Z. Therefore, the positive side switching element 51 and the negative side switching element 52 can be connected by a shorter current path. Therefore, the parasitic inductance in the current path 81 can be further suppressed.

The bypass conductor 11 is a wire. That is, no capacitor is arranged in the current path 81. Therefore, occurrence of a resonance phenomenon in the current path 81 can be suppressed. Further, the bypass conductor 11 can be formed at a low cost.
Further, the bypass conductor 11 may be a ribbon or a bus bar. This also has the same effect as when the bypass conductor 11 is a wire.

  As described above, according to the present embodiment, it is possible to provide the power conversion device 1 that can effectively suppress the parasitic inductance.

(Embodiment 2)
As shown in FIGS. 9 to 12, the present embodiment is an embodiment in which the arrangement of each element of the semiconductor module 7 such as the positive electrode side switching element 51 and the negative electrode side switching element 52 is changed with respect to the first embodiment.

  In the present embodiment, as shown in FIG. 10, a copper pattern layer 743 disposed opposite to each other with a positive electrode side switching element 51 and a negative electrode side switching element 52 interposed between the copper pattern layer 741 and the copper pattern layer 742. Have The copper pattern layer 741, the copper pattern layer 742, and the copper pattern layer 743 are opposed to each other in the thickness direction. Although not shown, the copper pattern layer 743 is connected to the output terminal 2, the copper pattern layer 741 is connected to the positive terminal 61, and the copper pattern layer 742 is connected to the negative terminal 62. Hereinafter, the facing direction between the copper pattern layer 743 and the copper pattern layers 741 and 742 is referred to as a facing direction F. Further, the copper pattern layer 743 side in the facing direction F is referred to as the upper side, and the copper pattern layer 741 and the copper pattern layer 742 side are referred to as the lower side.

  In the facing direction F, the positive electrode side switching element 51 and the negative electrode side switching element 52 are disposed between the copper pattern layer 741, the copper pattern layer 742, and the copper pattern layer 743. The positive side switching element 51 is disposed between the copper pattern layer 741 and the copper pattern layer 743. The negative electrode side switching element 52 is disposed between the copper pattern layer 742 and the copper pattern layer 743.

  The positive electrode side switching element 51 and the negative electrode side switching element 52 are arranged such that the collector and the emitter are located on opposite sides in the facing direction F. That is, the positive side switching element 51 has a collector 51c on the lower surface and an emitter 51e on the upper surface, whereas the negative side switching element 52 has a collector 52c on the upper surface and an emitter 52e on the lower surface.

  On the upper surface of the copper pattern layer 741, a bus bar 771 and a positive electrode side switching element 51 are sequentially laminated. Further, on the upper surface of the copper pattern layer 742, the negative electrode side switching element 52 and the bus bar 772 are sequentially laminated. That is, the stacking order of the bus bar and the switching element is opposite to each other on the upper side of the copper pattern layer 741 and the upper side of the copper pattern layer 742.

  Also in the present embodiment, the emitter 51 e of the positive electrode side switching element 51 is electrically connected to the output terminal 2 via the positive electrode side connection portion 3. In the present embodiment, the positive electrode side connection portion 3 is constituted by a part of the copper pattern layer 743. Further, the collector 52 c of the negative side switching element 52 is electrically connected to the output terminal 2 via the negative side connection part 4. In the present embodiment, the negative electrode side connection portion 4 is configured by a bus bar 772 and a part of the copper pattern layer 743. And although illustration was abbreviate | omitted, the positive electrode side connection part 3 and the negative electrode side connection part 4 are branched from the output terminal 2 via the connection part of the output terminal 2 and the copper pattern layer 743. That is, in the present embodiment, the branch portion 12 is a connection portion between the output terminal 2 and the copper pattern layer 743.

  As shown in FIG. 10, when the bypass conductor 11 is viewed from an orthogonal direction orthogonal to both the thickness direction and the alignment direction of the positive electrode side switching element 51 and the negative electrode side switching element 52, the positive electrode side switching element 51 and the negative electrode side switching element are connected. It is arranged between the element 52. The bypass conductor 11 is positioned inside both ends of the positive electrode side switching element 51 and the negative electrode side switching element 52 in a direction orthogonal to both the arrangement direction and the orthogonal direction.

  In the present embodiment, the bypass conductor 11 includes the vicinity of the position where the emitter 51 e of the positive electrode side switching element 51 is connected in the copper pattern layer 743 of the positive electrode side connection portion 3, and the lower end portion of the bus bar 772 of the negative electrode side connection portion 4. Is connected. Here, for convenience, a portion between the portion where the bus bar 771 is disposed and the portion where the negative-side switching element 52 is disposed in the copper pattern layer 743 is referred to as an intermediate portion 740. The positive side switching element 51 and the negative side switching element 52 are connected by both a current path via the bypass conductor 11 and a current path via the intermediate part 740. The current path connecting the positive side switching element 51 and the negative side switching element 52 is shorter in the current path via the bypass conductor 11 than in the current path via the intermediate portion 740.

  In the present embodiment, as shown in FIG. 9, the positive terminal 61, the negative terminal 62, and the output terminal 2 protrude on the same side in the direction orthogonal to the facing direction F. As shown in FIG. 10, the copper pattern layer 741 and the copper pattern layer 742 are disposed on the upper surface of the insulating layer 731. A copper pattern layer 721 and a base plate 71 are sequentially stacked on the lower surface of the insulating layer 731. In addition, an insulating layer 732, a copper pattern layer 722, and a base plate 712 are sequentially stacked on the upper surface of the copper pattern layer 743. In the present embodiment, the positive side switching element 51 and the negative side switching element 52 are configured to radiate heat to the two base plates 71.

  Others are the same as in the first embodiment. Of the reference numerals used in the second embodiment, the same reference numerals as those used in the above-described embodiments represent the same components as those in the above-described embodiments unless otherwise indicated.

  Also in the present embodiment, the current path 83 of the alternating current flowing through the positive electrode side switching element 51 and the negative electrode side switching element 52 can be shortened. That is, the current path 83 passing through the bypass conductor 11 shown in FIG. 11 is shorter than the current path 84 passing through the intermediate portion 740 shown in FIG. That is, the current path 83 is shorter than the current path 84 because it does not pass through the intermediate part 740 and hardly passes through the bus bar 772 of the negative electrode side connection part 4. Therefore, the parasitic inductance in the current path 83 of the alternating current passing through the positive electrode side switching element 51 and the negative electrode side switching element 52 can be suppressed. As a result, the surge voltage applied to the positive electrode side switching element 51 and the negative electrode side switching element 52 can be suppressed.

In addition, the same effects as those of the first embodiment are obtained.
The present invention is not limited to the above embodiments, and can be applied to various embodiments without departing from the spirit of the invention. For example, various parts having conductivity can be used as the bypass conductor. For example, the bypass conductor can include a capacitor.

DESCRIPTION OF SYMBOLS 1 Power converter 10 AC load 11 Bypass conductor 12 Branch part 2 Output terminal 3 Positive electrode side connection part 4 Negative electrode side connection part 51 Positive electrode side switching element 52 Negative electrode side switching element 61 Positive electrode terminal 62 Negative electrode terminal

Claims (4)

An output terminal (2) electrically connected to the AC load (10);
A positive electrode side connection portion (3) and a negative electrode side connection portion (4) branched from the output terminal via a branch portion (12);
A positive side switching element (51) connected to an end of the positive side connection part opposite to the output terminal;
A negative electrode side switching element (52) connected to an end of the negative electrode side connection portion opposite to the output terminal;
A positive terminal (61) electrically connected to the positive-side switching element;
A negative terminal (62) electrically connected to the negative side switching element;
An electrical connection is made between a portion on the positive electrode side switching element side with respect to the branch portion in the positive electrode side connection portion and a portion on the negative electrode side switching element side with respect to the branch portion in the negative electrode side connection portion. a bypass conductor (11), was closed,
In the longitudinal direction (Y) orthogonal to the alignment direction (X) of the positive electrode side switching element and the negative electrode side switching element, the positive electrode terminal, the negative electrode terminal, and the output terminal are the positive electrode side switching element and the negative electrode, respectively. Are arranged on opposite sides of the side switching element,
The bypass conductor is arranged between the positive electrode side switching element and the negative electrode side switching element when viewed from a height direction (Z) perpendicular to both the alignment direction and the vertical direction,
The power converter (1), wherein the positive-side switching element, the bypass conductor, and the negative-side switching element are arranged in the arrangement direction . The bypass conductor is a wire, a power converter according to claim 1. The bypass conductor is a ribbon, a power converter according to claim 1. The bypass conductor is a bus bar, the power conversion device according to claim 1.

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