JP6583137B2 - Power converter - Google Patents

Description

  The present invention relates to a power conversion device using a semiconductor element.

  For example, an electric vehicle, a hybrid vehicle, and the like are equipped with a power conversion device that converts DC power into AC power. In such a power conversion device, a power conversion circuit is constituted by a plurality of semiconductor elements. Since a large current flows through a semiconductor element, various structures for cooling a semiconductor module containing the semiconductor element are employed in order to suppress a high temperature due to heat generation.

  Here, if there is a difference between currents flowing through the plurality of semiconductor elements, a difference occurs in the amount of heat generated, which makes it difficult to perform thermal design. In the power conversion device disclosed in Patent Document 1, the shape of the bus bar branch portions of the positive electrode bus bar and the negative electrode bus bar connected to the plurality of semiconductor modules stacked together with the cooling pipe is the same shape. Thereby, it is possible to make the resistance value with respect to a direct current component equal among the currents supplied to each semiconductor module.

Japanese Patent Laying-Open No. 2015-139299

  However, when an alternating current flows through the positive electrode bus bar and the negative electrode bus bar, in addition to the resistance to the direct current component, the inductance also affects the impedance. Therefore, in a circuit configuration in which two semiconductor elements are connected in parallel and an alternating current flows through them at the same timing, the interaction between the bus bar branches connected to each semiconductor module is also supplied to each semiconductor element. Affects the impedance of the alternating current. That is, depending on the arrangement relationship of the plurality of bus bar branch portions, a difference occurs in the inductance in each bus bar branch portion, and a difference occurs in the impedance. If it does so, a difference may arise in the electric current which flows between the two semiconductor elements connected in parallel, and there exists a possibility that a calorific value may arise.

  Therefore, for example, when two semiconductor elements having the same heat resistance are used, it is necessary to perform thermal design based on a semiconductor element through which a larger amount of current flows. As a result, the semiconductor element may be increased in size and cost, and as a result, the entire power conversion device may be increased in size and cost.

  This invention is made | formed in view of this subject, and it aims at providing the power converter device which can suppress the difference of the electric current which flows into two semiconductor elements connected in parallel.

According to one embodiment of the present invention, two upper arm semiconductor elements (2u) connected in parallel to each other and two lower arm semiconductor elements (2d) connected in parallel to each other include a positive electrode wiring (30) and a negative electrode wiring (40 A power converter (1) having a configuration connected in series with
A positive electrode bus bar (3) constituting the positive electrode wiring;
A negative electrode bus bar (4) constituting the negative electrode wiring;
Two positive terminals (21) respectively connected to the two upper arm semiconductor elements;
Two negative terminals (22) respectively connected to the two lower arm semiconductor elements,
The positive bus bar and the negative bus bar include a bus bar body (31, 41) disposed so as to overlap each other in a main surface direction, and two bus bar protrusions (32, 42) protruding in one direction from the bus bar body. Respectively,
The two positive electrode protrusions (32) that are the bus bar protrusions of the positive electrode bus bar are respectively connected to the two positive electrode terminals,
Two negative electrode protrusions (42) that are the bus bar protrusions of the negative electrode bus bar are connected to the two negative electrode terminals, respectively.
The four bus bar protrusions are arranged side by side in a direction orthogonal to these protrusion directions (X),
The bus bar protruding portion is formed in a plate shape, and the main surface of the bus bar protruding portion faces the alignment direction (Y) of the four bus bar protruding portions,
And, among the four bus bars projecting portion, the both ends of the the arrangement direction, the two positive electrode projections or the two negative electrode protrusion is disposed, in the power converter.

  In the power conversion device, two positive electrode protrusions or two negative electrode protrusions are arranged at both ends in the arrangement direction of the four bus bar protrusions. Thereby, even if the influence of the mutual inductance between several bus-bar protrusion parts is considered, the difference of an inductance can be made small between two positive electrode protrusion parts and between two negative electrode protrusion parts. .

  That is, the inductance at each bus bar protrusion is a combination of the self-inductance at the bus bar protrusion and the mutual inductance received from the other bus bar protrusion. Here, by arranging the four bus bar protrusions in the order as described above, the influence of the mutual inductance received from the other bus bar protrusions between the two positive electrode protrusions, between the two negative electrode protrusions, You can get closer. Thereby, the difference of the combined inductance of the self-inductance and the mutual inductance can be reduced between the two positive electrode protrusions and between the two negative electrode protrusions.

Thereby, a difference in impedance can be suppressed between circuits each including two semiconductor elements connected in parallel to each other. Therefore, the difference in current flowing through each semiconductor element can be suppressed.
As a result, the thermal design of the power converter can be facilitated, the semiconductor element can be reduced in size and cost, and as a result, the entire power converter can be easily reduced in size and cost. .

As mentioned above, according to the said aspect, the power converter device which can suppress the difference of the electric current which flows into the two semiconductor elements connected in parallel can be provided.
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. It is not a thing.

FIG. 3 is a perspective view of a part of the power conversion device according to the first embodiment. The top view of a part of power converter device in Embodiment 1. FIG. The top view of the power converter device in Embodiment 1. FIG. The circuit diagram of the power converter device in Embodiment 1. FIG. Explanatory drawing of the inductance of four bus-bar protrusion parts in Embodiment 1. FIG. The circuit diagram of the power converter device in Embodiment 2. FIG. The top view of a part of power converter device in Embodiment 3. FIG. The perspective view of a part of power converter in a comparison form. The top view of a part of power converter device in a comparison form. Explanatory drawing of the inductance of four bus-bar protrusion parts in a comparison form.

(Embodiment 1)
An embodiment of a power conversion device will be described with reference to FIGS.
As shown in FIG. 4, the power conversion device 1 of the present embodiment includes two upper arm semiconductor elements 2 u connected in parallel to each other, and two lower arm semiconductor elements 2 d connected in parallel to each other, a positive electrode wiring 30 and a negative electrode The wiring 40 is connected in series.

  As shown in FIGS. 1 and 2, the power conversion device 1 includes a positive electrode bus bar 3, a negative electrode bus bar 4, two positive electrode terminals 21, and two negative electrode terminals 22. The positive electrode bus bar 3 is a bus bar constituting the positive electrode wiring 30. The negative electrode bus bar 4 is a bus bar constituting the negative electrode wiring 40. The two positive terminals 21 are terminals respectively connected to the two upper arm semiconductor elements 2u. The two negative terminals 22 are terminals respectively connected to the two lower arm semiconductor elements 2d.

  The positive electrode bus bar 3 and the negative electrode bus bar 4 have bus bar bodies 31 and 41 and two bus bar protrusions 32 and 42, respectively. That is, the positive electrode bus bar 3 includes a bus bar main body 31 and two bus bar protruding portions 32. The negative electrode bus bar 4 includes a bus bar main body 41 and two bus bar protrusions 42. The bus bar bodies 31 and 41 are disposed so as to overlap each other in the main surface direction. The two bus bar protrusions 32 and 42 protrude from the bus bar main bodies 31 and 41 in one direction.

Two positive electrode protrusions 32 that are bus bar protrusions of the positive electrode bus bar 3 are connected to the two positive electrode terminals 21, respectively. Two negative electrode protrusions 42, which are bus bar protrusions of the negative electrode bus bar 4, are connected to the two negative electrode terminals 22, respectively.
The four bus bar protrusions 32 and 42 are arranged side by side in a direction orthogonal to the protrusion direction X.

  Of the four bus bar protrusions 32 and 42, two positive electrode protrusions 32 or two negative electrode protrusions 42 are arranged at both ends in the arrangement direction Y. In the present embodiment, two negative electrode protrusions 42 are arranged at both ends in the alignment direction Y. Two positive electrode protrusions 32 are arranged between the two negative electrode protrusions 42 in the alignment direction Y.

  The positive terminal 21 extends from the semiconductor module 20 including at least the upper arm semiconductor element 2u. The negative terminal 22 extends from the semiconductor module 20 including at least the lower arm semiconductor element 2d. The extending direction Z of the positive electrode terminal 21 and the negative electrode terminal 22 and the protruding direction X of the bus bar protruding portions 32 and 42 are orthogonal to each other.

  In the present embodiment, as shown in FIG. 4, the upper arm semiconductor element 2 u and the lower arm semiconductor element 2 d are built in the same semiconductor module 20. As shown in FIGS. 1 and 2, a positive terminal 21 and a negative terminal 22 extend from the semiconductor module 20. Further, from the semiconductor module 20, an intermediate terminal 23 that conducts to a connection point between the upper arm semiconductor element 2u and the lower arm semiconductor element 2d also extends. The positive terminal 21, the negative terminal 22, and the intermediate terminal 23 extend in the same extending direction Z. Further, the positive electrode terminal 21, the negative electrode terminal 22, and the intermediate terminal 23 are made of a plate-like body, and are arranged so that the thickness direction faces the alignment direction Y.

  As shown in FIG. 4, the power conversion apparatus 1 of the present embodiment is configured to convert power between a DC power source 51 and a three-phase AC rotating electrical machine 52. The power conversion device 1 includes a smoothing capacitor 11 and an inverter circuit unit 12. The inverter circuit unit 12 is configured to drive the rotating electrical machine 52 by converting DC power into three-phase AC power. Moreover, the electric power generated in the rotating electrical machine 52 can be regenerated by converting it into direct current in the inverter circuit unit 12.

  The inverter circuit unit 12 includes three phases of legs formed by connecting the upper arm semiconductor element 2u and the lower arm semiconductor element 2d in series. Further, flywheel diodes are connected in reverse parallel to the upper arm semiconductor element 2u and the lower arm semiconductor element 2d, respectively. Connection points between the upper arm semiconductor element 2u and the lower arm semiconductor element 2d in each leg are connected to three electrodes of the rotating electrical machine 52, respectively.

  In the present embodiment, each of the upper arm semiconductor element 2u and the lower arm semiconductor element 2d constituting each phase in the inverter circuit unit 12 also has a parallel structure of two semiconductor elements. The positive electrode bus bar 3 connected to the two upper arm semiconductor elements 2u connected in parallel and the negative electrode bus bar 4 connected to the two lower arm semiconductor elements 2d connected in parallel are both configured as described above. It has become. The positive electrode protrusion 32 and the negative electrode protrusion 42 are each connected to a pair of electrodes of the smoothing capacitor 11. This connection structure is not shown.

  As shown in FIG. 4, the two upper arm semiconductor elements 2u are built in different semiconductor modules 20 connected in parallel to each other. The two lower arm semiconductor elements 2d are built in different semiconductor modules 20 connected in parallel to each other. The semiconductor modules 20 connected in parallel to each other are stacked in the arrangement direction Y.

As described above, the semiconductor module 20 includes one upper arm semiconductor element 2u and one lower arm semiconductor element 2d connected in series. Each semiconductor element is composed of an IGBT, that is, an insulated gate bipolar transistor. The emitter of the upper arm semiconductor element 2 u and the collector of the lower arm semiconductor element 2 d are connected to each other in the semiconductor module 20. This connection point is electrically connected to the intermediate terminal 23. Further, the collector of the upper arm semiconductor element 2 u is conducted to the positive terminal 21, and the emitter of the lower arm semiconductor element 2 d is conducted to the negative terminal 22.
The semiconductor element is not limited to the IGBT, and for example, a MOSFET, that is, a MOS field effect transistor can be used.

  Two semiconductor modules 20 configured as described above are connected in parallel to each other. Specifically, as shown in FIGS. 1 and 2, two semiconductor modules 20 are connected to each other at the same potential at the positive terminal 21, the negative terminal 22, and the intermediate terminal 23. The positive terminal 21 is connected to the positive bus bar 3, and the negative terminal 22 is connected to the negative bus bar 4. Although not shown, the intermediate terminal 23 is connected to a bus bar connected to the rotating electrical machine.

As shown in FIGS. 1 to 3, the semiconductor modules 20 connected in parallel to each other are arranged so as to be adjacent to each other in the alignment direction Y.
In addition, as shown in FIG. 3, the semiconductor module 20 is stacked with the cooling pipe 6. The cooling pipe 6 cools the semiconductor modules 20 from both sides in the alignment direction Y. That is, in the present embodiment, a plurality of cooling pipes 6 and a plurality of semiconductor modules 20 are alternately stacked. And the cooling pipe 6 is arrange | positioned so that both surfaces of the thickness direction of each semiconductor module 20 may contact | adhere.

  The cooling pipes 6 adjacent to each other in the stacking direction are connected to each other at both ends in the longitudinal direction. In addition, a refrigerant introduction pipe 61 and a refrigerant discharge pipe 62 are connected to both ends in the longitudinal direction of the cooling pipe 6 disposed at one end in the stacking direction. Thereby, the refrigerant introduced from the refrigerant introduction pipe 61 branches and flows into the plurality of cooling pipes 6 and is discharged from the refrigerant discharge pipe 62. The semiconductor module 20 is cooled by heat exchange between the semiconductor module 20 and the refrigerant while the refrigerant flows through the plurality of cooling pipes 6.

  The protruding direction X of the bus bar protruding portions 32, 42 coincides with the longitudinal direction of the cooling pipe 6. In addition, the arrangement direction Y of the bus bar protrusions 32 and 42 matches the stacking direction of the plurality of cooling pipes 6. The stacking direction of the bus bar main body 31 of the positive electrode bus bar 3 and the bus bar main body 41 of the negative electrode bus bar 4 coincides with the extending direction Z.

The positive electrode bus bar 3 and the negative electrode bus bar 4 are each formed by cutting and bending one metal plate.
In the present embodiment, the positive electrode bus bar 3 is formed by projecting positive electrode protrusions 32 which are six bus bar protrusions from the flat bus bar body 31 as shown in FIG. As shown in FIGS. 1 to 3, the positive electrode protrusions 32 connected to the two semiconductor modules 20 connected in parallel share one common protrusion 320 at the root portion. The common protrusion 320 has the same main surface direction as the bus bar body 31. The positive electrode protrusion 32 has a branch portion 321 branched from the common protrusion 320 into two. The branch portion 321 is bent at a substantially right angle from both ends of the common protruding portion 320 in the arrangement direction Y. Therefore, the main surface of the branching portion 321 faces the arrangement direction Y. The branch portion 321 extends in the protruding direction X and is bent in a crank shape on the way. The positive electrode protruding portion 32 is connected to the positive electrode terminal 21 of the semiconductor module 20 in the vicinity of the distal end portion of the branch portion 321. The positive electrode terminal 21 and the branch part 321 are connected so as to overlap in the arrangement direction Y.

  The negative electrode bus bar 4 is formed by projecting negative electrode protrusions 42 which are six bus bar protrusions from a flat bus bar main body 31. The negative electrode protruding portion 42 includes a root portion 420 and an extending portion 421 that further extends in the protruding direction X from the root portion 420. The root portion 420 has the same main surface direction as the bus bar body 41. The extending portion 421 is bent at a substantially right angle from one end of the root portion 420 in the arrangement direction Y. Therefore, the main surface of the extending portion 421 faces the arrangement direction Y. The negative electrode protruding portion 42 is connected to the negative electrode terminal 22 of the semiconductor module 20 in the vicinity of the distal end portion of the extending portion 421. The negative electrode terminal 22 and the extending portion 421 are connected so as to overlap in the arrangement direction Y.

  As shown in FIG. 2, the four bus bar protrusions 32 and 42 have a plane symmetrical shape with respect to a virtual plane S orthogonal to the arrangement direction Y. That is, the two positive electrode protrusions 32 have a mirror image shape, and the two negative electrode protrusions 42 also have a mirror image shape. The two positive electrode protrusions 32 have a plane-symmetric shape with reference to a virtual plane S that passes through the center of the common protrusion 320 in the alignment direction Y and is orthogonal to the alignment direction Y. Similarly, the two negative electrode protrusions 42 have a plane-symmetric shape with respect to the virtual plane S.

Next, the effect of this embodiment is demonstrated.
In the power conversion device 1, two negative electrode protrusions 42 are arranged at both ends in the arrangement direction Y of the four bus bar protrusions 32 and 42. Thereby, even if the influence of the mutual inductance between the plurality of bus bar protrusions 32 and 42 is taken into account, the difference in inductance between the two positive electrode protrusions 32 and between the two negative electrode protrusions 42 is reduced. Can be small.

  That is, the inductance at each bus bar protrusion 32, 42 is a combination of the self-inductance at the bus bar protrusion and the mutual inductance received from the other bus bar protrusion. Here, since the four bus bar protrusions 32 and 42 are arranged in the order as described above, the influence of the mutual inductance received from the other bus bar protrusions 32 and 42 is affected by the two positive electrode protrusions 32 and 2. The two negative electrode protrusions 42 can be brought close to each other. Thus, the difference in the combined inductance of the self-inductance and the mutual inductance can be reduced between the two positive electrode protrusions 32 and between the two negative electrode protrusions 42.

As shown in FIG. 5, a current flows through each bus bar protrusion 32, 42 in the direction indicated by the arrow i at the same timing. In this case, the inductance L32a in one positive electrode protrusion 32a of the two positive electrode protrusions 32 and the inductance L32b in the other positive electrode protrusion 32b can be expressed as follows.
L32a = Lpa-Mpana + Mpapb-Mpanb (1)
L32b = Lpb-Mpbna + Mpbpa-Mpbnb (2)

  Here, Lpa is the self-inductance of the positive electrode protrusion 32a, -Mpana is the mutual inductance between the positive electrode protrusion 32a and the negative electrode protrusion 42a, and Mpapb is between the positive electrode protrusion 32a and the positive electrode protrusion 32b. The mutual inductance, −Mpanb, represents the mutual inductance between the positive electrode protruding portion 32a and the negative electrode protruding portion 42b. Lpb is the self-inductance of the positive electrode protrusion 32b, -Mpbna is the mutual inductance between the positive electrode protrusion 32b and the negative electrode protrusion 42a, and Mpbpa is the mutual inductance between the positive electrode protrusion 32b and the positive electrode protrusion 32a. Inductance, -Mpbnb represents the mutual inductance between the positive electrode protrusion 32b and the negative electrode protrusion 42b.

Similarly, the inductance L42a in one negative electrode protrusion 42a of the two negative electrode protrusions 42 and the inductance L42b in the other negative electrode protrusion 42b can be expressed as follows.
L42a = Lna-Mnapa + Mnanb-Mnapb (3)
L42b = Lnb−Mnbpa + Mnbna−Mnbpb (4)

  Here, Lna is a self-inductance of the negative electrode protrusion 42a, -Mnpa is a mutual inductance between the negative electrode protrusion 42a and the positive electrode protrusion 32a, and Mnanb is between the negative electrode protrusion 42a and the negative electrode protrusion 42b. The mutual inductance, −Mnapb, represents the mutual inductance between the negative electrode protrusion 42a and the positive electrode protrusion 32b. Lnb is a self-inductance of the negative electrode protrusion 42b, -Mnbpa is a mutual inductance between the negative electrode protrusion 42b and the positive electrode protrusion 32a, and Mnbna is a mutual inductance between the negative electrode protrusion 42b and the negative electrode protrusion 42a. -Mnbpb represents the mutual inductance between the negative electrode protrusion 42b and the positive electrode protrusion 32b.

The four bus bar protrusions 32a, 32b, 42a, 42b form a plane-symmetric shape with respect to the virtual plane S orthogonal to the arrangement direction Y. Therefore, the above self-inductance and mutual inductance have the following relationship.
Lpa = Lpb
Mpana = Mpbnb
Mpapb = Mpbpa
Mpanb = Mpbna
Lna = Lnb
Mnapa = Mnbpb
Mnanb = Mnbna
Mnappb = Mnbpa

  By substituting these relationships into equations (1) to (4), L32a = L32b and L42a = L42b are established. That is, the inductances in the two positive electrode protrusions 32 are equal, and the inductances in the two negative electrode protrusions 42 are equal.

Thereby, a difference in impedance can be suppressed between circuits each including two semiconductor elements connected in parallel to each other. Therefore, the difference in current flowing through each semiconductor element can be suppressed.
As a result, the thermal design of the power conversion device 1 can be facilitated, the semiconductor element can be reduced in size and cost, and as a result, the entire power conversion device 1 can be easily reduced in size and cost. Can do.

  The upper arm semiconductor element 2u and the lower arm semiconductor element 2d are built in the same semiconductor module 20. Therefore, the wiring between the semiconductor elements can be shortened, and the impedance can be further reduced.

  The semiconductor modules 20 connected in parallel to each other are arranged so as to be adjacent to each other in the alignment direction Y. Therefore, the effect of the arrangement of the bus bar protrusions 32 and 42 in consideration of the mutual inductance can be effectively obtained.

  As described above, according to the present embodiment, it is possible to provide a power conversion device that can suppress a difference in current flowing through two semiconductor elements connected in parallel.

(Embodiment 2)
As shown in FIG. 6, the power conversion device 1 of the present embodiment includes a booster circuit unit 13 and an inverter circuit unit 12.
The booster circuit unit 13 is configured to boost the voltage of the DC power supply 51 and supply power to the inverter circuit unit 12.

  The booster circuit unit 13 includes an upper arm semiconductor element 2u, a lower arm semiconductor element 2d, and a reactor 53 connected to a connection point between them. Further, flywheel diodes are connected in reverse parallel to the upper arm semiconductor element 2u and the lower arm semiconductor element 2d, respectively.

Each of the upper arm semiconductor element 2u and the lower arm semiconductor element 2d constituting the booster circuit unit 13 has a parallel structure of two semiconductor elements.
Other configurations are the same as those of the first embodiment.
Of the reference numerals used in the second and subsequent embodiments, 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.

In the present embodiment, also in the booster circuit unit 13, it is possible to suppress a difference in current flowing through two semiconductor elements connected in parallel.
In addition, the same effects as those of the first embodiment are obtained.

(Embodiment 3)
In the present embodiment, as shown in FIG. 7, the semiconductor module 201 provided with the positive terminal 21 and the semiconductor module 202 provided with the negative terminal 22 are formed as individual semiconductor modules.
In other words, in the present embodiment, the semiconductor modules 201 and 202 containing one semiconductor element are connected in series. The semiconductor element incorporated in one semiconductor module 201 is the upper arm semiconductor element 2u, and the semiconductor element incorporated in the other semiconductor module 202 is the lower arm semiconductor element 2d. The two semiconductor modules 201 and 202 may have the same structure.

  Each of these semiconductor modules 201 and 202 includes two power terminals. One power terminal in the semiconductor module 201 becomes the positive terminal 21, and the other power terminal becomes the intermediate terminal 23. In addition, one power terminal in the semiconductor module 202 becomes the negative terminal 22, and the other power terminal becomes the intermediate terminal 23. The intermediate terminal 23 in the two semiconductor modules 201 and 202 is connected to a bus bar connected to the rotating electrical machine 52, for example. The connection structure of the intermediate terminal 23 is not shown.

  Two semiconductor modules 201 and 202 connected in series with each other are arranged in the protruding direction X. Further, two semiconductor modules 201 adjacent to each other in the arrangement direction Y and two semiconductor modules 202 adjacent to each other in the arrangement direction Y are connected in parallel. The positive electrode protrusion 32 of the positive electrode bus bar 3 is connected to the positive electrode terminal 21 of the semiconductor module 201. The negative electrode protrusion 42 of the negative electrode bus bar 4 is connected to the negative electrode terminal 22 of the semiconductor module 202.

Of the four bus bar protrusions 32, 42, two negative electrode protrusions 42 are arranged at both ends in the alignment direction Y. Two positive electrode protrusions 32 are arranged between the two negative electrode protrusions 42 in the alignment direction Y.
Other configurations are the same as those of the first embodiment.
Also in this embodiment, the same effect as Embodiment 1 can be obtained.

(Comparison form)
8 to 10 show a configuration in which the positive electrode protrusions 32 and the negative electrode protrusions 42 are alternately arranged as a comparative form.
In this comparative embodiment, as shown in FIG. 9, the two positive electrode protrusions 32 have the same shape, and the two negative electrode protrusions 42 have the same shape. And the positive electrode protrusion part 32 and the negative electrode protrusion part 42 are arranged alternately, the negative electrode protrusion part 42 is distribute | arranged to the end in the row direction Y, and the positive electrode protrusion part 32 is distribute | arranged to the other end.
With such an arrangement of the four bus bar protrusions 32 and 42, a difference in inductance is likely to occur between the two positive electrode protrusions 32 and between the two negative electrode protrusions 42.

  In the same manner as in the first embodiment, the inductances L32a, L32b, L42a, and L42b at the protruding portions of the bus bars can be expressed as the above formulas (1) to (4) in consideration of the self-inductance and the mutual inductance. .

  However, the four bus bar protrusions 32a, 32b, 42a, 42b are alternately arranged in the arrangement direction Y. Therefore, unlike the case of the first embodiment, the mutual inductance is unbalanced. That is, a difference occurs between the inductance L32a and the inductance L32b, and a difference also occurs between the inductance L42a and the inductance L42b.

Specifically, the relationship between each self-inductance and each mutual inductance is as follows.
Lpa = Lpb
Mpana = Mpbnb
Mpapb = Mpbpa
Mpanb> Mpbna
Lna = Lnb
Mnapa = Mnbpb
Mnanb = Mnbna
Mnappb <Mnbpa

  When these relationships are substituted into the above formulas (1) to (4), L32a <L32b and L42a> L42b.

Therefore, in this comparative embodiment, a difference in impedance occurs between circuits each including two semiconductor elements connected in parallel to each other.
On the other hand, in the power converters of Embodiments 1 to 3, as described above, the inductance difference | L32a-L32b | between the two positive electrode protrusions 32 and the inductance difference between the two negative electrode protrusions 42 | L42a-L42b | can be suppressed. Therefore, the difference in impedance can be suppressed, and the difference in current flowing through the two semiconductor elements connected in parallel can be suppressed.

The present invention is not limited to the above embodiments, and can be applied to various embodiments without departing from the scope of the invention.
For example, in the power conversion device of the second embodiment, only the upper arm semiconductor element 2u and the lower arm semiconductor element 2d constituting the booster circuit unit 13 may have a parallel structure of two semiconductor elements.
Moreover, in the said Embodiment 1, 3, although the structure where the two negative electrode protrusion parts are distribute | arranged to the both ends of these alignment directions among the four bus-bar protrusion parts was shown, it is not restricted to this. That is, it can also be set as the structure which has arrange | positioned two positive electrode protrusion parts in the both ends of the alignment direction of four bus-bar protrusion parts.

DESCRIPTION OF SYMBOLS 1 Power converter 2u Upper arm semiconductor element 2d Lower arm semiconductor element 20, 201, 202 Semiconductor module 21 Positive electrode terminal 22 Negative electrode terminal 3 Positive electrode bus bar 32 Positive electrode protrusion part (bus bar protrusion part)
4 Negative bus bar 42 Negative electrode protrusion (bus bar protrusion)

Claims (7)

Two upper arm semiconductor elements (2u) connected in parallel to each other and two lower arm semiconductor elements (2d) connected in parallel to each other are connected in series between the positive electrode wiring (30) and the negative electrode wiring (40). A power conversion device (1) having the configuration as described above,
A positive electrode bus bar (3) constituting the positive electrode wiring;
A negative electrode bus bar (4) constituting the negative electrode wiring;
Two positive terminals (21) respectively connected to the two upper arm semiconductor elements;
Two negative terminals (22) respectively connected to the two lower arm semiconductor elements,
The positive bus bar and the negative bus bar include a bus bar body (31, 41) disposed so as to overlap each other in a main surface direction, and two bus bar protrusions (32, 42) protruding in one direction from the bus bar body. Respectively,
The two positive electrode protrusions (32) that are the bus bar protrusions of the positive electrode bus bar are respectively connected to the two positive electrode terminals,
Two negative electrode protrusions (42) that are the bus bar protrusions of the negative electrode bus bar are connected to the two negative electrode terminals, respectively.
The four bus bar protrusions are arranged side by side in a direction orthogonal to these protrusion directions (X),
The bus bar protruding portion is formed in a plate shape, and the main surface of the bus bar protruding portion faces the alignment direction (Y) of the four bus bar protruding portions,
And, among the four bus bars projecting portion, the both ends of the the arrangement direction, the two positive electrode projections or the two negative electrode protrusion is disposed, the power conversion device.   2. The power conversion device according to claim 1, wherein the four bus bar protruding portions form a plane-symmetric shape with reference to a virtual plane (S) orthogonal to the arrangement direction.   The positive terminal extends from a semiconductor module (20, 201) including at least the upper arm semiconductor element, and the negative terminal extends from a semiconductor module (20, 202) including at least the lower arm semiconductor element. The power conversion device according to claim 1, wherein an extending direction of the positive terminal and the negative terminal and a protruding direction of the bus bar protruding portion are orthogonal to each other.   The electric power according to claim 3, wherein the upper arm semiconductor element and the lower arm semiconductor element are built in the same semiconductor module, and the positive terminal and the negative terminal extend from the semiconductor module. Conversion device.   The two upper arm semiconductor elements are housed in different semiconductor modules connected in parallel to each other, and the two lower arm semiconductor elements are housed in different semiconductor modules connected in parallel to each other. The power conversion device according to claim 3 or 4, wherein the connected semiconductor modules are stacked in the arrangement direction.   The power conversion device according to claim 5, wherein the semiconductor modules connected in parallel to each other are arranged adjacent to each other in the arrangement direction.   The said semiconductor module is a power converter device of Claim 5 or 6 laminated | stacked with the cooling pipe (6) which cools this semiconductor module from the both surfaces of the said alignment direction.

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