WO2022064958A1 - Power conversion device - Google Patents

Abstract

This power conversion device comprises a semiconductor device (20), capacitors (21), a positive electrode bus bar (22a), and a negative electrode bus bar (22b). The positive electrode bus bar (22a) and the negative electrode bus bar (22b) have a coupling plate portion (22c), a capacitor connection portion (22d), and a semiconductor connection portion (22e). The capacitor connection portion (22d) extends from the coupling plate portion (22c) and makes contact with the capacitors (21). The semiconductor connection portion (22e) extends from the coupling plate portion (22c) and is connected to the semiconductor device (20). At least one of the positive electrode bus bar (22a) and the negative electrode bus bar (22b) forms a projection portion (25) on the coupling plate portion (22c). Since the rigidity of the coupling plate portion (22c) is increased by the projection portion (25), it is possible to reduce the effect of vibration transmitted from the capacitors (21) to the coupling plate portion (22c).

Description

Power converter Cross-reference of related applications

This application is based on Patent Application No. 2020-162513 filed in Japan on September 28, 2020, and the contents of the basic application are incorporated by reference as a whole.

This disclosure relates to a power conversion device.

The power conversion device of Patent Document 1 includes a bus bar connecting a capacitor and a semiconductor device. An AC voltage is applied to the capacitor as the power converter operates. Charges are accumulated in the electrodes of the capacitor by the AC voltage, and Coulomb force is generated between the electrodes. Since the Coulomb force changes periodically in proportion to the frequency of the AC voltage, the capacitor vibrates.

Japanese Unexamined Patent Publication No. 2019-20152

In the power conversion device, when the capacitor vibrates, the vibration of the capacitor is transmitted to the bus bar. When the vibration transmitted from the capacitor is large, the bus bar vibrates greatly, and there is a possibility that the bus bar is transmitted to another member connected to the bus bar, for example, a semiconductor device.

This disclosure is based on this circumstance, and its purpose is to provide a power conversion device that can reduce the influence of vibration that the bus bar receives from the capacitor.

A first aspect of the present disclosure for achieving this object is a semiconductor device that converts power, a capacitor that smoothes the power supplied from the battery and supplies it to the semiconductor device, and a capacitor connection connected to the semiconductor. A pair of bus bars having a section, a semiconductor connection section connected to the semiconductor device, and a connecting plate section connecting the capacitor connecting section and the semiconductor connecting section are provided, and the bus bar is provided with a connecting plate section. It is a power conversion device having a protruding portion protruding from the surface.

Since the connecting plate portion is formed with the protruding portion, the rigidity of the connecting plate portion is higher than that of the connecting plate portion without the protruding portion. Therefore, even when vibration is transmitted from the capacitor, the connecting plate portion has high rigidity due to the protruding portion, so that vibration of the connecting plate portion itself is suppressed. Therefore, the bus bar can reduce the influence of vibration from the capacitor.

It is a circuit diagram of the power conversion system of 1st Embodiment. It is a figure which showed the structure of the power conversion apparatus of 1st Embodiment. It is a figure which showed the structure of the power conversion apparatus of 1st Embodiment. FIG. 2 is a sectional view taken along line IV-IV of FIG. It is a figure which showed the structure of the bus bar of 1st Embodiment. It is a figure which showed the structure of the power conversion apparatus of 2nd Embodiment. FIG. 6 is a cross-sectional view taken along the line VII-VII of FIG. It is a figure which showed the structure of the bus bar of another embodiment. It is a figure which showed the structure of the bus bar of another embodiment. It is a figure which showed the structure of the power conversion apparatus of another embodiment. It is a figure which showed the structure of the bus bar of another embodiment.

Hereinafter, a plurality of embodiments of the present disclosure will be described with reference to the drawings. By assigning the same reference numerals to the corresponding components in each embodiment, duplicate description may be omitted. When only a part of the configuration is described in each embodiment, the configuration of the other embodiment described above can be applied to the other parts of the configuration. Further, not only the combination of the configurations specified in the description of each embodiment but also the configurations of a plurality of embodiments can be partially combined even if the combination is not specified. Further, an unspecified combination of the configurations described in the plurality of embodiments and modifications is also disclosed by the following description.

(First Embodiment)
As shown in FIG. 1, the power conversion system 1 includes a battery 11, a power conversion device 12, and a motor 13. The battery 11 supplies electric power to the power conversion device 12 via the energized bus bar 24. The power conversion device 12 converts the electric power and supplies the converted electric power to the motor 13 via the motor bus bar 23. The motor 13 in the present disclosure is, for example, a motor used as a power source for a vehicle.

As shown in FIG. 2 or 3, the power conversion device 12 includes an inverter case 26, a semiconductor device 20, a capacitor 21, a capacitor case 27, a bus bar 22, and a cooler 28. The inverter case 26 houses a semiconductor device 20, a condenser 21, a condenser case 27, a bus bar 22, and a cooler 28 inside. The bus bar 22 is a generic name for both the positive electrode bus bar 22a and the negative electrode bus bar 22b.

FIG. 3 is a drawing in which the capacitor case 27 and the inverter case 26 of FIG. 2 are not shown. The semiconductor device 20 is composed of a plurality of switching elements 20a. As shown in FIG. 3, the plurality of switching elements 20a are arranged in a stacked manner.

In the present embodiment, as shown by the arrow in FIG. 3, the X direction indicates the directions on both sides of the direction in which the semiconductor connecting portion 22e extends from the connecting plate portion 22c. As shown by the arrows in FIG. 3, the Y direction indicates the directions on both sides of the stacking direction of the plurality of switching elements 20a. Further, as shown by the arrows in FIG. 4, the Z direction indicates the directions on both sides of the connecting plate portion 22c in the thickness direction.

As shown in FIG. 3, the switching element 20a has a P terminal 20b, an N terminal 20c, and an output terminal 20d. The P terminal 20b, the N terminal 20c, and the output terminal 20d are formed so as to extend in the longitudinal direction in the Z direction.

The P terminal 20b is in contact with the semiconductor connection portion 22e of the positive electrode bus bar 22a on the surfaces facing each other in the Y direction. The semiconductor connection portion 22e of the P terminal 20b and the positive electrode bus bar 22a is fixed in contact with each other by, for example, welding. Further, the direction in which the P terminal 20b, the N terminal 20c, and the output terminal extend is defined as one side in the Z direction.

The N terminal 20c is in contact with the semiconductor connection portion 22e of the negative electrode bus bar 22b on the surfaces facing each other in the Y direction. The semiconductor connection portion 22e of the N terminal 20c and the negative electrode bus bar 22b is fixed in contact with each other by, for example, welding. The output terminal 20d is connected to the motor bus bar 23.

As shown in FIG. 3 or 4, the cooler 28 is arranged on the other side in the Z direction with respect to the connecting plate portion 22c. The cooler 28 is arranged in contact with or close to the semiconductor device 20 on the surface. The cooler 28 cools the surroundings by passing a cooling fluid such as LLC through a pipe or the like in the cooler 28. Therefore, the semiconductor device 20 is cooled at a portion close to the cooler 28.

As shown in FIG. 3, the power conversion device 12 has a plurality of capacitors 21. The capacitor 21 has a rectangular shape having a long side in the X direction and a short side in the Y direction when viewed in the Z direction. The plurality of capacitors 21 are arranged so that their long sides face each other in the Y direction. That is, the plurality of capacitors 21 are arranged so as to be arranged in the Y direction.

FIG. 4 omits the illustration of the semiconductor device 20 and the insulating member 29. As shown in FIG. 4, the capacitor 21 is electrically connected to the capacitor connection portion 22d of the positive electrode bus bar 22a on the surface on one side in the Z direction. The capacitor 21 is electrically connected to the capacitor connection portion 22d of the negative electrode bus bar 22b on the surface on the other side in the Z direction. Further, the capacitor 21 is housed inside the capacitor case 27. The inside of the capacitor case 27 is filled with, for example, a resin encapsulant 30. Therefore, the periphery of the capacitor 21 is filled with the sealing material 30.

The power conversion device 12 has a positive electrode bus bar 22a and a negative electrode bus bar 22b, which are a pair of bus bars 22. As shown in FIG. 3 or 4, the positive electrode bus bar 22a and the negative electrode bus bar 22b have a connecting plate portion 22c, a capacitor connecting portion 22d, a semiconductor connecting portion 22e, and a protruding portion 25. The positive electrode bus bar 22a and the negative electrode bus bar 22b are formed by, for example, a press or the like. The connecting plate portion 22c has a thickness in the Z direction and has a plate shape forming an XY plane.

As shown in FIG. 3 or 4, the connecting plate portion 22c of the positive electrode bus bar 22a and the connecting plate portion 22c of the negative electrode bus bar 22b are arranged so that the XY planes overlap each other in the Z direction. That is, the connecting plate portions 22c of the positive electrode bus bar 22a and the negative electrode bus bar 22b are arranged close to each other so that the XY planes face each other in the Z direction. In the present disclosure, overlapping of planes means that at least a part of the planes face each other, and does not mean that all the planes face each other.

As shown in FIG. 5, the insulating member 29 is arranged between the connecting plate portion 22c of the positive electrode bus bar 22a and the negative electrode bus bar 22b in the Z direction. The insulating member 29 is arranged so as to be close to or in contact with the positive electrode bus bar 22a and the negative electrode bus bar 22b. The insulating member 29 allows the positive electrode bus bar 22a and the negative electrode bus bar 22b to secure insulation from each other.

As shown in FIG. 3, the capacitor connecting portion 22d extends from the connecting plate portion 22c toward one side in the X direction. That is, the capacitor connection portion 22d extends from the connecting plate portion 22c toward the capacitor 21 side.

As shown in FIG. 4, the capacitor connection portion 22d is arranged inside the capacitor case 27, and the periphery thereof is filled with the sealing material 30. Therefore, the capacitor connection portion 22d is prevented from moving by the sealing material 30. On the other hand, the connecting plate portion 22c is arranged outside the capacitor case 27.

As shown in FIG. 3, the semiconductor connecting portion 22e is formed so as to extend in the longitudinal direction from the connecting plate portion 22c to the other side in the X direction. That is, the semiconductor connection portion 22e extends from the connecting plate portion 22c to the semiconductor device 20 side. The power conversion device 12 has a plurality of semiconductor connection portions 22e, and the plurality of semiconductor connection portions 22e are arranged so as to be arranged in the Y direction. The direction in which the plurality of semiconductor connection portions 22e are lined up is the same as the direction in which the plurality of capacitors 21 are lined up.

As shown in FIG. 3, the positive electrode bus bar 22a has a protruding portion 25 formed on the connecting plate portion 22c. Similarly, the negative electrode bus bar 22b forms a protruding portion 25 on the connecting plate portion 22c. Although not shown in the drawing of FIG. 3, the protruding portion 25 of the negative electrode bus bar 22b is formed at a position overlapping the protruding portion 25 of the positive electrode bus bar 22a when viewed from one side in the Z direction.

As shown in FIG. 5, the protruding portion 25 has a step forming portion 25a, a flat plate portion 25b, and a boundary portion 25c. The step forming portion 25a of the positive electrode bus bar 22a extends from the boundary portion 25c, which is the boundary portion between the connecting plate portion 22c and the step forming portion 25a, at an angle α with respect to the connecting plate portion 22c. That is, the step forming portion 25a of the positive electrode bus bar 22a is an inclined surface that is inclined with respect to the connecting plate portion 22c. The angle α is, for example, an angle in the range of 10 degrees to 90 degrees.

The flat plate portion 25b of the positive electrode bus bar 22a is formed so as to extend in the X direction from the end portion on the opposite side of the boundary portion 25c of the step forming portion 25a. The flat plate portion 25b forms an XY plane parallel to the connecting plate portion 22c. Further, the flat plate portion 25b is arranged at a position separated from the connecting plate portion 22c on one side in the Z direction by a distance d1 in the Z direction.

As shown in FIG. 5, the step forming portion 25a is a portion connecting the connecting plate portion 22c and the flat plate portion 25b. That is, the step forming portion 25a is a part of the portion forming the step between the connecting plate portion 22c and the flat plate portion 25b.

As shown in FIG. 2, the boundary portion 25c is formed in an annular shape when viewed in the Z direction. The outer peripheral edge of the flat plate portion 25b is connected to the step forming portion 25a on the entire circumference. The boundary portion 25c is formed in a rectangular shape having a long side 25g and a short side 25h. The long side 25g is formed so as to extend in the Y direction which is the longitudinal direction of the boundary portion 25c, and the two long sides 25g are formed so as to face each other in the X direction which is the lateral direction of the boundary portion 25c. ..

The short side 25h connects two long sides 25g and has an arcuate shape. The connecting plate portion 22c has a rectangular shape having a longitudinal direction in the Y direction and a lateral direction in the X direction when viewed in the Z direction. Therefore, the direction in which the long side 25g is formed is the Y direction, which coincides with the longitudinal direction of the connecting plate portion 22c.

As shown in FIG. 5, the direction 31 of the current of the positive electrode bus bar and the direction 32 of the current of the negative electrode bus bar are opposite to each other. The first region line 34 shown in FIG. 3 is a line connecting the semiconductor connection portion 22e located at one end of the plurality of semiconductor connection portions 22e in the Y direction and the capacitor connection portion 22d at the shortest distance. .. The second region line 35 is a line connecting the semiconductor connection portion 22e located at the other end in the Y direction of the plurality of semiconductor connection portions 22e and the capacitor connection portion 22d at the shortest distance.

The facing region 33 shown by diagonal lines in FIG. 3 is a range sandwiched between the first region line 34 and the second region line 35, and is a range in which the semiconductor connecting portion 22e and the capacitor connecting portion 22d face each other in the X direction. be. That is, the facing region 33 indicates a range in which the semiconductor connecting portion 22e and the capacitor connecting portion 22d overlap in the X direction. The positive electrode bus bar 22a does not form the protrusion 25 within the range of the facing region 33.

The positive electrode bus bar 22a forms a protruding portion 25 outside the range of the facing region 33 in the connecting plate portion 22c. That is, the protruding portion 25 is formed at a position on the connecting plate portion 22c on the other side in the Y direction with respect to the second region line 35. The protrusion 25 is formed at a position on the other side in the Y direction with respect to the semiconductor connection portion 22e located at the other end in the Y direction.

The capacitor 21 connected to the portion of the capacitor connecting portion 22d that overlaps the facing region 33 in the X direction does not face the protruding portion 25 in the X direction. On the other hand, at least one of the capacitors 21 connected to the portion of the capacitor connecting portion 22d that does not overlap with the facing region 33 in the X direction faces the protruding portion 25 in the X direction.

The plurality of semiconductor connecting portions 22e do not face the protruding portions 25 in the X direction. Further, the protruding portion 25 is located on a diagonal line connecting the semiconductor connecting portion 22e and the portion of the capacitor connecting portion 22d that does not overlap with the facing region 33 in the X direction. Further, the negative electrode bus bar 22b, like the positive electrode bus bar 22a, forms a protruding portion 25 outside the range in which the semiconductor connecting portion 22e and the capacitor connecting portion 22d face each other in the X direction.

As shown in FIG. 5, the step forming portion 25a of the negative electrode bus bar 22b is inclined in the opposite direction in the Z direction to the step forming portion 25a of the positive electrode bus bar 22a with respect to the connecting plate portion 22c. That is, the protruding portion 25 of the negative electrode bus bar 22b protrudes in the direction opposite to the protruding direction of the protruding portion 25 of the positive electrode bus bar 22a in the Z direction.

The step forming portion 25a of the negative electrode bus bar 22b forms an angle β with respect to the connecting plate portion 22c and extends from the boundary portion 25c. In the present embodiment, since the angle α and the angle β are the same, the flat plate portion 25b of the negative electrode bus bar 22b is also separated from the connecting plate portion 22c by a distance d1 in the Z direction, similarly to the positive electrode bus bar 22a.

As shown in FIG. 4, the cooler 28 is arranged on the other side in the Z direction from the positive electrode bus bar 22a and the negative electrode bus bar 22b. Further, the negative electrode bus bar 22b is arranged on the other side in the Z direction with respect to the positive electrode bus bar 22a, and the protruding portion 25 is formed so as to project to the other side in the Z direction.

As shown in FIG. 3, the connecting plate portion 22c has an energized connecting portion 22f extending in the longitudinal direction on the other side in the X direction. That is, the energized connection portion 22f extends in the same direction as the direction in which the semiconductor connection portion 22e extends from the connecting plate portion 22c. Further, the energized connection portions 22f of the positive electrode bus bar 22a and the negative electrode bus bar 22b are arranged so as to line up in the Y direction.

The energized connection portion 22f is arranged at a position facing the semiconductor connection portion 22e in the Y direction. However, the energized connection portion 22f is formed on the other side in the Y direction with respect to the portion of the connecting plate portion 22c where the semiconductor connection portion 22e is formed.

The energized connection portion 22f has, for example, a fastening hole 22g, and is fastened to a conductive member with a screw or the like at the fastening hole 22g. Further, the conductive member is connected to the battery 11 arranged on the outside of the capacitor case 27. The current that reaches the energized connection portion 22f from the battery 11 is transmitted to the connecting plate portion 22c. Then, the current that reaches the connecting plate portion 22c is transmitted to the semiconductor connecting portion 22e.

The step forming portion 25a shown in FIG. 4 has a higher geometrical moment of inertia in the Z direction than the connecting plate portion 22c. Therefore, the connecting plate portion 22c has a higher geometrical moment of inertia in the Z direction in the entire connecting plate portion 22c as compared with the connecting plate portion that does not form the protruding portion 25. Therefore, the connecting plate portion 22c has high rigidity against vibration in the Z direction.

Since the connecting plate portion 22c has higher rigidity due to the protruding portion 25 as compared with the configuration in which the protruding portion 25 is not formed, vibration of the connecting plate portion 22c itself is suppressed. Therefore, the bus bar 22 can reduce the influence of vibration from the capacitor 21. Further, the power conversion device 12 can suppress the vibration of the bus bar 22 by the protrusion 25 even when the number of the plurality of capacitors 21 is increased and the vibration received by the bus bar 22 from the plurality of capacitors 21 increases.

The positive electrode bus bar of the first comparative example has a welded portion in which the semiconductor connecting portion and the P terminal are connected by welding, and is not fixed by another member such as a fastening member. Further, the positive electrode bus bar of the first comparative example does not form a protruding portion in the connecting plate portion. When vibration is transmitted from the capacitor to the positive electrode bus, the capacitor connection portion is filled with a sealing material, so that vibration is suppressed.

However, since the connecting plate portion of the positive electrode bus bar of the first comparative example is arranged outside the capacitor case and is not fixed by a sealing material, a fastening member, or the like, vibration is suppressed more than that of the capacitor connecting portion. Not. Therefore, when the vibration of the capacitor is transmitted to the connecting plate portion, the connecting plate portion vibrates more in the Z direction than the capacitor connecting portion.

Then, the vibration of the connecting plate portion is transmitted to the semiconductor junction portion, and the semiconductor junction portion vibrates in the Z direction, so that stress is applied to the welded portion with the P terminal. As a result, in the welded portion, the portion in contact between the P terminal and the semiconductor connection portion may be separated from each other.

On the other hand, the positive electrode bus bar 22a of the present embodiment has a protruding portion 25 formed on the connecting plate portion 22c. Therefore, since the positive electrode bus bar 22a itself is suppressed from vibrating by the protruding portion 25, it is possible to suppress the application of stress to the contact portion between the semiconductor connecting portion 22e and the P terminal 20b due to the vibration of the connecting plate portion 22c. Therefore, the positive electrode bus bar 22a can connect the semiconductor connecting portion 22e and the P terminal 20b without using other members such as a fastening member. Therefore, the positive electrode bus bar 22a can be prevented from becoming large.

As shown in FIG. 2, the positive electrode bus bar 22a of the present embodiment has a boundary portion 25c formed in an annular shape when viewed in the Z direction. That is, the protruding portion 25 does not reach the outer peripheral edge 22h of the connecting plate portion. Therefore, the connecting plate portion 22c is manufactured with good dimensional accuracy in the X direction because the outer peripheral edge 22h of the connecting plate portion is formed by a normal flat surface.

As shown in FIG. 3, the connecting plate portion 22c of the present embodiment forms a protruding portion 25 by matching its longitudinal direction with the direction of its long side 25g. The protruding portion 25 of the present embodiment can form a long side 25 g up to a length in the longitudinal direction of the connecting plate portion 22c.

Therefore, the connecting plate portion 22c of the present embodiment can form the protruding portion 25 larger than the configuration in which the longitudinal directions of the connecting plate portion 22c and the protruding portion 25 do not match. Therefore, the connecting plate portion 22c of the present embodiment can suppress its own vibration by forming the protruding portion 25 to be large.

As shown in FIG. 5, the connecting plate portions 22c of the positive electrode bus bar 22a and the negative electrode bus bar 22b are arranged close to each other in the Z direction. Further, the direction 31 of the current of the positive electrode bus bar and the direction 32 of the current of the negative electrode bus bar are opposite to each other. The direction of the magnetic flux generated around one current and the direction of the magnetic flux generated around the other current are opposite. Therefore, the magnetic flux generated around one current and the other current cancel each other out.

Therefore, the positive electrode bus bar 22a and the negative electrode bus bar 22b can suppress an increase in inductance when a current flows. On the other hand, the flat plate portions 25b of the positive electrode bus bar 22a and the negative electrode bus bar 22b have a larger separation distance in the Z direction than the connecting plate portions 22c. Therefore, the currents flowing through the flat plate portion 25b have a lower degree of canceling the magnetic flux than the currents flowing through the connecting plate portion 22c, so that the inductance increases.

The semiconductor device 20 has the smallest impedance between the plurality of capacitors 21 and the capacitor 21 having a short distance from the semiconductor device 20. That is, the current exchanged between the semiconductor device 20 and the capacitor 21 has the smallest impedance when passing through the facing region 33 shown in FIG. 3 because the distance between the semiconductor connection portion 22e and the capacitor connection portion 22d is the smallest.

When a high frequency surge occurs in the switching element 20a due to a switching operation or the like, the high frequency surge passes through a path having a low impedance. Therefore, the high frequency surge is transmitted from the semiconductor device 20 to the capacitor 21 through the facing region 33.

As shown in FIG. 3, the connecting plate portion 22c of the present embodiment forms a protruding portion 25 on the outside of the facing region 33. When the high frequency surge flows, the connecting plate portion 22c has a protruding portion 25 formed on the outside of the facing region 33 where a large amount of the high frequency surge flows, so that the protruding portion 25 is formed in the facing region 33 as compared with the case where the protruding portion 25 is formed. It is possible to suppress an increase in the length of the current path due to the length of the protrusion 25. Therefore, the connecting plate portion 22c can suppress the increase in the inductance by suppressing the increase in the current path due to the protruding portion 25.

As shown in FIG. 5, the negative electrode bus bar 22b of the present embodiment has a protruding portion 25 protruding to the other side in the Z direction on the connecting plate portion 22c. That is, the negative electrode bus bar 22b has a protruding portion 25 that protrudes in the direction opposite to the direction in which the protruding portion 25 of the positive electrode bus bar 22a protrudes.

Therefore, the positive electrode bus bar 22a and the negative electrode bus bar 22b of the present embodiment have a larger separation distance between the flat plate portions 25b in the Z direction than, for example, a configuration in which the negative electrode bus bar 22b does not have the protruding portion 25 formed. Therefore, the positive electrode bus bar 22a and the negative electrode bus bar 22b can suppress the heat generated by the current flowing through the flat plate portion 25b from being transferred to the flat plate portion 25b of the other bus bar 22.

As shown in FIG. 4, the negative electrode bus bar 22b of the present embodiment forms a protruding portion 25 protruding to the other side in the Z direction. Further, the cooler 28 is arranged on the other side in the Z direction with respect to the negative electrode bus bar 22b. Therefore, the negative electrode bus bar 22b of the present embodiment can approach the cooler 28 at the protruding portion 25 in the Z direction from the configuration in which the protruding portion 25 is not formed on the negative electrode bus bar 22b. Therefore, the efficiency of cooling the negative electrode bus bar 22b of the present embodiment by the cooler 28 increases.

(Second Embodiment)
The power conversion system 1 in this embodiment has the same configuration as that in the first embodiment. Therefore, in this embodiment, the same reference numerals as those in the first embodiment are used. In this embodiment, the differences from the first embodiment will be mainly described.

As shown in FIG. 6, in the boundary portion 25c, one end 25d and the other end 25e of the boundary portion 25c are located on the outer peripheral edge 22h of the connecting plate portion 22c when viewed from one side in the Z direction. Further, one end 25d and the other end 25e are separated in the Y direction. As shown in FIGS. 6 and 7, the flat plate portion 25b is formed up to the position of the outer peripheral edge 22h of the connecting plate portion 22c.

As shown in FIG. 5, the flat plate portion 25b of the first embodiment has step forming portions 25a extending on both sides in the X direction. In FIG. 5, W1 indicates the width of the step forming portion 25a. Since the connecting plate portion 22c of the first embodiment is provided with the step forming portions 25a on both sides of the flat plate portion 25b in the X direction, the step forming portion 25a is twice as long as W1 in the length of the connecting plate portion 22c in the X direction. Will occupy the length of.

On the other hand, in the flat plate portion 25b of the present embodiment, as shown in FIG. 7, the step forming portion 25a extends on one side in the X direction, but the step forming portion 25a is not formed on the other side in the X direction. In FIG. 7, W2 indicates the width of the step forming portion 25a. In the connecting plate portion 22c of the present embodiment, the step forming portion 25a occupies the length of W2 in the length of the connecting plate portion 22c in the X direction.

Therefore, the step forming portion 25a of the present embodiment can form W2 to a length longer than W1. Therefore, in the connecting plate portion 22c of the present embodiment, d2 corresponding to the height of the step forming portion 25a shown in FIG. 7 in the Z direction is set to the distance of the step forming portion 25a of the first embodiment shown in FIG. 5 in the Z direction. It can be formed longer than d1.

As shown in FIG. 7, the protruding portion 25 of the negative electrode bus bar 22b of the present embodiment protrudes in the same direction as the protruding portion 25 of the positive electrode bus bar 22a in the Z direction. Therefore, in the positive electrode bus bar 22a and the negative electrode bus bar 22b, the step forming portions 25a and the flat plate portions 25b are formed at the same distance in the Z direction as the connecting plate portions 22c.

Therefore, in the positive electrode bus bar 22a and the negative electrode bus bar 22b of the present embodiment, the step forming portions 25a and the flat plate portions 25b are arranged closer to each other as compared with the configuration in which the protruding portions 25 of the positive electrode bus bar and the negative electrode bus bar 22b have different protruding directions. Can be made to. Therefore, since the distance between the currents flowing through the protruding portions 25 of the positive electrode bus bar 22a and the negative electrode bus bar 22b of the present embodiment is short, it is possible to suppress an increase in the inductance of the current flowing through the protruding portions 25.

(Other embodiments)
Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and the following embodiments are also included in the technical scope of the present disclosure. It can be changed and implemented within a range that does not deviate.

Although it is described that the protruding portion 25 has the step forming portion 25a and the flat plate portion 25b, it may be configured not to have the flat plate portion 25b as shown in FIG. In that case, the step forming portion 25a protrudes from the connecting plate portion 22c in the Z direction, and the shape of the XZ cross section is formed in, for example, an arc shape. The step forming portion 25a is integrally connected to the connecting plate portion 22c at the boundary portions 25c which are the ends on both sides in the X direction.

Although it is described that the bus bar 22 has the energized connection portion 22f, the bus bar 22 may be configured not to have the energized connection portion 22f.

Although the boundary portion 25c is described as having a rectangular shape, it may have a shape having no long side such as a perfect circle or a square.

Although it is described that the direction 31 of the current of the positive electrode bus bar and the direction 32 of the current of the negative electrode bus bar are opposite to each other, they may be in the same direction.

It is described that the protruding portions 25 of the positive electrode bus bar 22a and the negative electrode bus bar 22b are arranged so as to overlap each other when viewed in the Z direction, but at least a part thereof may be overlapped or not all overlapped.

Although it is described that the protruding portion 25 is formed on the outside of the facing region 33, it may be formed on the inside of the facing region 33. Alternatively, a part of the protrusion 25 may be formed so as to be inside the range of the facing region 33.

Although it is described that the angle α and the angle β are the same, the angle α and the angle β may be different.

The positive electrode bus bar 22a and the negative electrode bus bar 22b in FIG. 8 have a shape in which the flat plate portions 25b are connected to the step forming portions 25a on both sides in the X direction as in the first embodiment. Further, the protruding portions 25 of the positive electrode bus bar 22a and the negative electrode bus bar 22b may be projected in the same direction as shown in FIG.

As shown in FIG. 9, the protrusion 25 may be formed only on the positive electrode bus bar 22a. In FIG. 9, the negative electrode bus bar 22b does not form the protruding portion 25. Similarly, the negative electrode bus bar 22b may have a protruding portion 25, and the positive electrode bus bar 22a may not have a protruding portion 25.

As shown in FIG. 10, the connecting plate portion 22c may have a configuration having a plurality of protruding portions 25. As shown in FIG. 10, it is desirable that the plurality of projecting portions 25 have long sides 25g facing each other in the X direction.

In the above embodiment, it is described that there are two bus bars in contact with the capacitor 21, a positive electrode bus bar 22a and a negative electrode bus bar 22b, but three or more bus bars are in contact with each other, and at least one bus bar is a connecting plate. The protrusion 25 may be formed in the portion 22c.

The connecting plate portion 22c may be composed of a plurality of members instead of a single member. For example, the connecting plate portion 22c is composed of a first connecting plate portion having a capacitor connecting portion 22d and a second connecting plate portion having a semiconductor connecting portion 22e. The first connecting plate portion and the second connecting plate portion are electrically connected to each other, and a protruding portion 25 is formed on at least one of the first connecting plate portion and the second connecting plate portion.

In the above embodiment, the configuration described as the configuration of the positive electrode bus bar 22a is applicable to the negative electrode bus bar 22b. Similarly, the configuration described as applicable to the negative electrode bus bar 22b is applicable to the positive electrode bus bar 22a.

Claims (9)

1. A semiconductor device (20) that converts electric power,
   A capacitor (21) that smoothes the power supplied from the battery (11) and supplies it to the semiconductor device,
   A capacitor connection portion (22d) connected to the capacitor, a semiconductor connection portion (22e) connected to the semiconductor device, and a connecting plate portion connecting the capacitor connection portion and the semiconductor connection portion (a connecting plate portion). 22c) and a pair of bus bars, each with.
   The bus bar is a power conversion device having a protruding portion (25) protruding from the connecting plate portion.
2. The protrusion is
   A flat plate portion (25b) provided at a position deviated from the connecting plate portion in the thickness direction of the connecting plate portion and forming a surface parallel to the connecting plate portion.
   The power conversion device according to claim 1, further comprising a step forming portion (25a) that connects the connecting plate portion and the flat plate portion to form a step.
3. The power conversion device according to claim 2, wherein the boundary portion (25c), which is the boundary between the connecting plate portion and the step forming portion, is formed in an annular shape when viewed in the thickness direction.
4. The boundary portion (25c), which is the boundary between the connecting plate portion and the step forming portion, has one end (25d) and the other end (25d) on the outer peripheral edge (22h) of the connecting plate portion when viewed in the thickness direction. The power conversion device according to claim 2, wherein 25e) are formed apart from each other.
5. The connecting plate portion has a rectangular shape having a longitudinal direction when viewed in the thickness direction.
   The boundary portion is formed in a rectangular shape having a longitudinal direction when viewed in the thickness direction.
   The power conversion device according to claim 3 or 4, wherein the longitudinal direction of the boundary portion is the same as the longitudinal direction of the connecting plate portion.
6. It has multiple of the above capacitors and
   The pair of bus bars are arranged close to each other so that the connecting plate portions overlap each other in the thickness direction of the connecting plate portion, and the directions of the currents flowing through the connecting plate portions are opposite to each other.
   The power conversion device according to any one of claims 1 to 5, wherein the protruding portion is provided outside the facing region (33) where the semiconductor connection portion and the capacitor connection portion face each other.
7. The pair of bus bars have the protrusions, are arranged so that the connecting plates and the protrusions overlap each other in the thickness direction of the connecting plates, and the direction of the current flowing through the connecting plates is different. Opposite to each other,
   The power conversion device according to any one of claims 1 to 6, wherein the protruding direction of the protruding portion of one of the bus bars is the same as the protruding direction of the protruding portion of the other bus bar.
8. The pair of bus bars have the protrusions, and are arranged so that the connecting plates and the protrusions overlap each other in the thickness direction of the connecting plates.
   The power conversion device according to any one of claims 1 to 6, wherein the protruding direction of the protruding portion of one of the bus bars is opposite to the protruding direction of the protruding portion of the other bus bar.
9. A cooler (28) for cooling the semiconductor device is provided.
   The pair of bus bars have the protrusions, and are arranged so that the connecting plates and the protrusions overlap each other in the thickness direction of the connecting plates.
   The cooler is arranged on one side in the thickness direction with respect to the connecting plate portion.
   Any of claims 1 to 8, wherein the bus bar located on the one side in the thickness direction of the pair of bus bars has the protruding portion protruding to the one side in the thickness direction. The power conversion device according to item 1.

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