JP2014027768A - Capacitor and power conversion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a capacitor capable of further reducing the floating inductance of bus bars and a power conversion device using the capacitor.SOLUTION: A capacitor 1 includes a capacitor element 2, a case 4, a pair of bus bars 3 (3a and 3b), and a sealing member 5. The capacitor element 2 is housed in the case 4. The pair of bus bars 3 are electrically connected to the capacitor element 2. A bus-bar opposite portion 6 is formed in the capacitor 1. The bus-bar opposite portion 6 is formed by oppositely disposing an inner extension portion 31 that is formed in the bus bar 3 and extends along a side wall 40 in the case 4 and an outer extension portion 32 that is formed in the bus bar 3 and extends along the side wall 40 outside the case 4 with the side wall 40 interposed therebetween. The directions of currents I each flowing through the inner extension portion 31 and the outer extension portion 32 are opposite to each other.

Description

  The present invention relates to a capacitor including a bus bar and a case, and a power conversion device using the capacitor.

  A capacitor for use in a power conversion device such as an inverter includes a capacitor element, a case for housing the capacitor element, and a pair of bus bars electrically connected to the capacitor element (Patent Document 1 below). reference).

  The pair of bus bars are connected to other electronic components in the power conversion device. In some capacitors, the pair of bus bars are arranged to face each other at a predetermined interval in order to reduce the floating inductance of the bus bars. Since the directions of the currents flowing through the pair of bus bars are opposite to each other, when these bus bars are arranged to face each other, the magnetic fields generated around the bus bars by the current can be canceled out. Therefore, the floating inductance of the bus bar can be reduced.

  One end of the bus bar is connected to the electrode of the capacitor element, is bent inside the case, and extends out of the case. The other end of the bus bar is connected to the electronic component outside the case. Of the pair of bus bars, the portions existing outside the case are arranged to face each other as described above.

JP 2008-99397 A

  However, in the capacitor described in Patent Document 1, only the portions outside the case of the pair of bus bars face each other, and the portions inside the case do not face each other. Therefore, there is a problem that it is difficult to increase the area of the portion where the bus bars are opposed to each other, and it is difficult to sufficiently reduce the inductance of the bus bar.

  The present invention has been made in view of such a background, and an object of the present invention is to provide a capacitor that can further reduce the floating inductance of a bus bar, and a power conversion device using the capacitor.

One embodiment of the present invention includes a capacitor element;
A case for housing the capacitor element;
A pair of bus bars electrically connected to the capacitor element;
In the case, comprising a sealing member for sealing the capacitor element and the pair of bus bars,
A bus bar facing portion in which a part of the bus bar is opposed to each other or between the pair of bus bars is formed,
The bus bar facing portion includes an inner extending portion formed on the bus bar and extending along the side wall of the case in the case, and an outer extending portion formed on the bus bar and extending along the side wall outside the case. The capacitor is characterized in that the protruding portions are arranged opposite to each other across the side wall, and the directions of the currents flowing through the inner extending portion and the outer extending portion are opposite to each other. Item 1).

  According to another aspect of the present invention, there is provided a power conversion device including the capacitor and a semiconductor module incorporating a semiconductor element, the semiconductor module being disposed adjacent to the capacitor, and the power terminal of the semiconductor module being The power converter is characterized in that it protrudes toward the capacitor and the pair of bus bars are connected to the power terminal.

In the capacitor, the bus bar facing portion is formed by disposing the inner extending portion and the outer extending portion so as to sandwich the side wall of the case. Therefore, not only the portion of the bus bar that exists on the outside of the case but also the portion that exists on the inside of the case (inner extending portion) can be made to face other portions of the bus bar. Thereby, the area of the part which mutually opposes in a bus bar can be enlarged more.
In addition, the two portions (inner extension portion and outer extension portion) facing each other have currents flowing in opposite directions.
As described above, the capacitor can further increase the area of the portion of the bus bar that is opposite to each other and the directions of the currents are opposite to each other, so that the floating inductance can be further reduced.

  In the power converter, the semiconductor module is disposed adjacent to the capacitor, and the power terminal of the semiconductor module protrudes toward the capacitor. Therefore, the distance between the capacitor and the power terminal can be shortened. As a result, the length of the bus bar can be shortened, and the floating inductance of the bus bar can be further reduced.

  As described above, according to the present invention, it is possible to provide a capacitor that can further reduce the floating inductance of the bus bar, and a power conversion device using the capacitor.

Sectional drawing of the power converter device in Example 1. FIG. II-II sectional drawing of FIG. The principal part enlarged view of FIG. IV-IV sectional drawing of FIG. VV sectional drawing of FIG. FIG. 3 is a plan view of a case, a frame, and a positive electrode bus bar in Example 1. FIG. 3 is a plan view of a case, a frame, and a negative electrode bus bar in Example 1. The circuit diagram of the power converter device in Example 1. FIG. Sectional drawing of the power converter device in Example 2. FIG. XX sectional drawing of FIG. Sectional drawing of the power converter device in Example 3. FIG. XII arrow line view of FIG. FIG. 10 is a partial perspective side view of the capacitor in the fourth embodiment. The circuit diagram of the power converter device in Example 4. FIG.

In the capacitor, the bus bar facing portion is preferably formed by bending one of the bus bars.
Since it is necessary to reverse the direction of the current flowing through each of the inner extension portion and the outer extension portion, the shape of the bus bar tends to be complicated when the bus bar facing portion is formed using two bus bars. On the other hand, when one bus bar is bent to form the bus bar facing portion, the bus bar is bent in a U-shape to form the inner extension portion and the outer extension portion, and the side wall of the case is interposed therebetween. You can do it. Therefore, the shape of the bus bar can be simplified, and the manufacturing cost of the bus bar can be easily reduced.

In addition, it is preferable that the outer extending portions are formed on the pair of bus bars, respectively, and the pair of outer extending portions are arranged adjacent to each other (Claim 3).
In this case, the outer extending portion of one bus bar and the outer extending portion of the other bus bar are arranged adjacent to each other, and the directions of the currents flowing in the respective bus bars are opposite to each other. The stray inductance between the extending portions can be reduced. Therefore, the floating inductance of the bus bar can be further reduced.

The length of the bus bar facing portion in the normal direction of the bottom surface of the case is preferably longer than the length of the capacitor element in the normal direction.
In this case, since the length of the bus bar facing portion is long, the floating inductance of the bus bar can be sufficiently reduced.

Example 1
Embodiments relating to the capacitor and the power conversion device will be described with reference to FIGS. As shown in FIG. 1, the capacitor 1 of this example includes a capacitor element 2, a case 4, a pair of bus bars 3 (3 a and 3 b), and a sealing member 5. The capacitor element 2 is accommodated in the case 4. The pair of bus bars 3 are electrically connected to the capacitor element 2. The sealing member 5 seals the capacitor element 2 and the pair of bus bars 3 in the case 4.

One bus bar 3 is formed with a bus bar facing portion 6 in which part of the bus bars 3 are opposed to each other.
The bus bar facing portion 6 is formed on the bus bar 3 and extends inside the case 4 along the side wall 40 of the case 4, and the bus bar facing portion 6 is formed on the bus bar 3 and extends along the side wall 40 outside the case 4. The outer extending portion 32 is disposed so as to face the side wall 40. The directions of the currents I flowing in the inner extension portion 31 and the outer extension portion 32 are opposite to each other.

As shown in FIG. 3, one end face of the capacitor element 2 is a positive electrode 21, and the other end face is a negative electrode 22. The negative electrode 22 is located on the side close to the bottom surface 41 of the case 4 in the Z direction, and the positive electrode 21 is located on the side close to the case opening 42 in the Z direction.
The pair of bus bars 3 includes a positive electrode bus bar 3 a connected to the positive electrode 21 and a negative electrode bus bar 3 b connected to the negative electrode 22.

  A plurality of capacitor elements 2 are accommodated in the case 4 (see FIG. 2). The capacitor element 2 is made of a film capacitor, for example. Case 4 is made of metal. The negative side connection plate portion 320 of the negative electrode bus bar 3b is connected to all the negative electrodes 22 of the plurality of capacitor elements 2. As shown in FIG. 3, the inner extension portion 31 (31 b) extends from the negative connection plate portion 320 in the normal direction (Z direction) of the bottom surface 41. A connecting portion 34 straddling the side wall 40 of the case 4 is formed at the tip of the inner extending portion 31b. The connection part 34 protrudes in the plate | board thickness direction (Y direction) of the inner side extension part 31b. Further, an outer extension 32 (32b) extends in the Z direction from the tip of the connecting portion 34. The inner extension part 31b and the outer extension part 32b are opposed to each other, and the side wall 40 is interposed therebetween. The bus bar facing portion 6 is configured by the inner extending portion 31b and the outer extending portion 32b. The Z-direction lengths of the inner extension portion 31b and the outer extension portion 32b are substantially equal.

  Further, the protrusion 35 (35b) protrudes in the Y direction from the tip of the outer extension 32b. The protrusion 35b is connected to a negative module connection plate 315 (see FIG. 7) described later.

  Moreover, as shown in FIG. 3, the extension part 321 is extended in the Z direction from the negative side connection board part 320. As shown in FIG. And the negative side connection terminal 39 protrudes in the Y direction from the front-end | tip of the extension part 321 on the opposite side to the side in which the said connection part 34 was provided. The negative side connection terminal 39 is connected to a negative electrode of a DC power supply 8 (see FIG. 8) described later.

  Further, as shown in FIG. 4, the positive side connection plate portion 310 of the positive electrode bus bar 3 a is connected to the positive electrode 21 of the capacitor element 2. Similarly to the negative electrode bus bar 3b, the positive electrode bus bar 3a includes an inner extension portion 31 (31a), a connecting plate portion 34, an outer extension portion 32 (32a), and an extension portion 321. The inner extension portion 31a and the extension portion 321 of the positive electrode bus bar 3a are shorter in the Z direction than that of the negative electrode bus bar 3b. The outer extending portion 32a of the positive electrode bus bar 3a has a longer length in the Z direction than the inner extending portion 31a. The outer extending portion 32a of the positive bus bar 3a has a shorter length in the Z direction than the outer extending portion 32b (see FIG. 3) of the negative bus bar 3b. The inner extension portion 31a of the positive bus bar 3a and a part of the outer extension portion 32a are opposed to each other through the side wall 40 of the case 4 to constitute an auxiliary bus bar facing portion 60. A protrusion 35 (35a) protruding in the Y direction is formed at the tip of the outer extension 32a. The protrusion 35a is connected to a positive module connection plate 316 (see FIG. 6) described later.

  Further, as shown in FIG. 4, a positive connection terminal 38 protruding in the Y direction is provided at the tip of the extending portion 321 of the positive electrode bus bar 3a. The positive connection terminal 38 is connected to the positive electrode of a DC power supply 8 (see FIG. 8) described later.

  As shown in FIG. 5, the outer extending portion 32a of the positive electrode bus bar 3a and the outer extending portion 32b of the negative electrode bus bar 3b are disposed adjacent to each other. The directions of the current I flowing through these outer extending portions 32a and 32b are opposite to each other.

  As shown in FIGS. 1 and 2, the capacitor 1 of this example is used in a power conversion device 10. The power conversion device 10 includes a stacked body 100 in which a plurality of semiconductor modules 7 and a plurality of cooling pipes 13 (refrigerant flow paths) are stacked. A semiconductor element 73 (see FIG. 8) is built in the main body 72 of the semiconductor module 7. A coolant 16 that cools the semiconductor module 7 flows through the cooling pipe 13.

  The semiconductor module 7 includes a control terminal 71 and a power terminal 70. The power terminal 70 is electrically connected to the capacitor 1, and the control circuit board 11 is connected to the control terminal 71. The power terminal 70 includes a positive terminal 70a, a negative terminal 70b, and an AC terminal 70c. The positive terminal 70 a is connected to the positive bus bar 3 a of the capacitor 1, and the negative terminal 70 b is connected to the negative bus bar 3 b of the capacitor 1. The AC terminal 70 c is connected to a later-described three-phase AC motor 80 (see FIG. 8) via the AC bus bar 39. By controlling the switching operation of the semiconductor module 7 by the control circuit board 11, the DC voltage applied between the positive terminal 70 a and the negative terminal 70 b is changed to an AC voltage, and the three-phase AC motor 80 is driven. .

  As shown in FIG. 2, connecting pipes 17 are attached to both ends of the cooling pipe 13 in the Y direction. By this connecting pipe 17, two cooling pipes 13 adjacent in the stacking direction (X direction) of the stacked body 100 are connected. In addition, an inlet pipe 14 for introducing the refrigerant 16 and an outlet pipe 15 for leading the refrigerant 16 are connected to the cooling pipe 13a located at one end in the X direction. When the refrigerant 16 is introduced from the introduction pipe 14, the refrigerant 16 flows through all the cooling pipes 13 through the connecting pipe 17 and is led out from the outlet pipe 15. Thereby, the semiconductor module 7 is cooled.

  Further, the power conversion device 10 includes a metal frame 12. The frame 12 is formed integrally with the case 4 of the capacitor 1. The laminated body 100 is fixed inside the frame 12.

  An elastic member 18 (plate spring) is interposed between one of the wall portions 121 and 122 of the frame 12 orthogonal to the X direction and the laminate 100. The laminate 100 is pressed in the X direction by the elastic force of the elastic member 18 and pressed against the other wall portion 122 of the frame 12. Thereby, the laminated body 100 is fixed in the frame 12 while maintaining the contact pressure between the cooling pipe 13 and the semiconductor module 7.

  As shown in FIG. 1, the positive module connection plate 316 is connected to the positive terminal 70 a of the semiconductor module 7. As shown in FIG. 6, the positive module connecting plate 316 includes a plate-like main body portion 317 connected to the protrusion 35 a and a comb-like portion 318 extending from the plate-like main body portion 317 in the Y direction. The tips of the comb-like portions 318 are superposed on the positive terminal 70a of the semiconductor module 7 and are electrically connected by welding or the like.

  Further, as shown in FIG. 1, the negative module connection plate 315 is connected to the negative terminal 70 b of the semiconductor module 7. As shown in FIG. 7, the negative module connecting plate 315 includes a plate-like main body 313 connected to the protrusion 35 b and a comb-like portion 314 extending from the plate-like main body 313 in the Y direction. The comb-like portion 314 is connected to the negative electrode terminal 70 of the semiconductor module 7.

  As shown in FIG. 1, the plate-like main body portion 313 of the negative-side module connection plate 315 and the plate-like main body portion 317 of the positive-side module connection plate 316 are disposed to face each other with a predetermined interval in the Z direction.

  Next, a circuit diagram of the power conversion device 10 will be described. As shown in FIG. 8, the power conversion device 10 of this example includes a plurality of IGBT elements (semiconductor elements 73). This IGBT element constitutes a bridge circuit. A free wheel diode 74 is connected in reverse parallel to each IGBT element. The main body 72 of the semiconductor module 7 described above incorporates one IGBT element and one free wheel diode 74.

  The power conversion device 10 is connected to a DC power supply 8. The capacitor 1 is provided to smooth the DC voltage of the DC power supply 8.

The effect of this example will be described. In this example, as shown in FIGS. 1 and 3, the bus bar facing portion 6 is formed by arranging the inner extending portion 31 and the outer extending portion 32 to face each other with the side wall 40 of the case 4 interposed therebetween. . Therefore, not only the portion of the bus bar 3 that exists outside the case 4, but also the portion that exists inside the case 4 (inner extending portion 31) can be made to face other portions of the bus bar 3. Thereby, the area of the part which mutually opposes in the bus bar 3 can be enlarged more.
In addition, the two portions (the inner extension portion 31 and the outer extension portion 32) that are opposed to each other have the directions of the currents I flowing in opposite directions.
As described above, the capacitor 1 of this example can further increase the area of the portions of the bus bar 3 that are opposite to each other and in which the directions of the currents I are opposite to each other, so that the floating inductance can be further reduced. .

Further, in this example, as shown in FIGS. 1 and 3, the bus bar facing portion 6 is formed by bending one bus bar 3 (negative electrode bus bar 3b).
Since the inner extension portion 31 and the outer extension portion 32 need to reverse the directions of the current I flowing therethrough, when the bus bar facing portion 6 is formed using the two bus bars 3 (3a, 3b), The shape of the bus bar 3 tends to be complicated. On the other hand, when one bus bar 3 is bent to form the bus bar facing portion 6, the bus bar 3 is bent in a U shape to form the inner extension portion 31 and the outer extension portion 32, and between them. The side wall of the case 4 may be interposed. Therefore, the shape of the bus bar 3 can be simplified, and the manufacturing cost of the bus bar 3 can be easily reduced.

Further, in this example, outer extending portions 32 are formed in the pair of bus bars 3a and 3b, respectively. As shown in FIG. 5, the pair of outer extending portions 32 are arranged adjacent to each other in the X direction.
In this case, the outer extending portion 32a of one bus bar 3a and the outer extending portion 32b of the other bus bar 3b are arranged adjacent to each other, and the direction of the current I flowing in each of them is opposite. The stray inductance between these two outer extending portions 32a and 32b can be reduced. Therefore, the floating inductance of the bus bar 3 can be further reduced.

Further, in this example, as shown in FIG. 3, the length of the bus bar facing portion 6 in the Z direction is longer than the length of the capacitor element 2 in the Z direction.
In this way, since the bus bar facing portion 6 is long, the floating inductance of the negative bus bar 3b can be sufficiently reduced.

Further, in this example, as shown in FIG. 1, the plate-like main body portion 313 of the negative-side module connection plate 315 and the plate-like main body portion 317 of the positive-side module connection plate 316 are opposed to each other at a predetermined interval in the Z direction. It is.
Therefore, stray inductance between the two plate-like main body portions 313 and 317 can also be reduced.

Further, in this example, of the pair of bus bars 3a and 3b, the bus bar facing portion 6 is formed on one bus bar 3 (negative electrode bus bar 3b), and the auxiliary bus bar facing portion 60 (see FIG. 5) is formed on the other bus bar 3 (positive bus bar 3a). 4) is formed.
In the auxiliary bus bar facing portion 60, the inner extension portion 31a and the outer extension portion 32a have currents I flowing in opposite directions. Therefore, in the auxiliary bus bar facing portion 60, the floating inductance of the positive bus bar 3a can be reduced.

  Moreover, in this example, as shown in FIG. 3, the inner side extension part 31a of the positive side bus bar 3a and the part of the inner side extension part 31b of the negative side bus bar 3b are adjacently arranged. In these two inner extending portions 31a and 31b, the directions of currents flowing in the two inner extending portions 31a and 31b are opposite. Therefore, the stray inductance between the two inner extension portions 31a and 31b can be reduced.

  As described above, according to this example, it is possible to provide a capacitor that can further reduce the floating inductance of the bus bar, and a power converter using the capacitor.

  In the above embodiment, as shown in FIG. 2, an example in which the coolant channel is formed by the cooling pipe 13 and the cooling pipe 13 is brought into contact with the semiconductor module 2 has been described. Is not limited to this. That is, for example, a coolant channel can be provided so that the coolant 16 is in direct contact with the semiconductor module 7.

  Further, in this example, as shown in FIG. 2, the elastic member 18 is provided on the side far from the introduction pipe 14 and the lead-out pipe 15 in the X direction, but may be provided on the side close to the lead-in pipe 14 and the lead-out pipe 15. Good. For example, even if the elastic member 18 is provided between the other wall portion 122 of the frame 12 and the laminate 100, and the laminate 100 is pressed and fixed to the one wall portion 121 side by the elastic member 18. Good.

  Further, in this example, as shown in FIGS. 6 and 7, the bus bars 3a and 3b and the module connection plates 315 and 316 are each formed by a single metal plate, but these are formed as separate members by welding or the like. You may connect.

(Example 2)
In this example, as shown in FIGS. 9 and 10, the bus bar facing portion 6 is formed by using two bus bars 3 (3a, 3b). In this example, the inner extension portion 31b formed on the negative bus bar 3b and the outer extension portion 32d formed on the positive bus bar 3a are opposed to each other with the wall portion 40 of the case 4 interposed therebetween, whereby the bus bar facing portion. 6 is formed. The inner extension 31b of the negative bus bar 3b extends in the Z direction from the negative connection plate 320. A connecting portion 34 b that straddles the wall portion 40 of the case 4 is formed at the tip of the inner extending portion 31. The connecting portion 34b is connected to the negative module connection plate 315.

Similarly to the first embodiment, the positive bus bar 3 includes a positive connection plate part 310, an inner extension part 31a, and a connecting part 34a. Further, as shown in FIG. 10, the positive bus bar 3 includes two outer extending portions 32 (32 c and 32 d). Of the two outer extending portions 32, one outer extending portion 32c is connected to the connecting portion 34a. The two outer extending portions 32c and 32d are connected to each other by the connecting portion 38 at the end portion on the case bottom surface 41 (see FIG. 9) side in the Z direction. The other outer extension 32d is connected to the positive module connection plate 316 (see FIG. 9) at the end on the case opening 42 side in the Z direction.
Others are the same as in the first embodiment. Moreover, among the symbols used in the drawings relating to this example, the same symbols as those used in the first embodiment represent the same components as in the first embodiment unless otherwise indicated.

(Example 3)
In this example, the structure of the laminate 100 is changed. As shown in FIGS. 11 and 12, in this example, a plurality of variable body modules 7 and a plurality of cooling pipes 13 are stacked in the Z direction. The stacked body 100 is placed on the bottom 125 of the frame 12. And using the elastic member which is not illustrated, the laminated body 100 is pressed to the Z direction, and is pressed and fixed to the bottom part 125. FIG.

  The laminated body 100 is disposed at a position adjacent to the capacitor 1 in the Y direction. The positive terminal 70a and the negative terminal 70b of the semiconductor module 7 protrude to the capacitor 1 side in the Y direction. Further, the AC terminal 70c protrudes from the main body portion 72 on the opposite side to the protruding side of the positive terminal 70a and the negative terminal 70b. The AC bus bar 39 is connected to the AC terminal 70c.

  The negative terminal 70b and the negative bus bar 3b are electrically connected via the connection member 19 (19b). The connection member 19b includes a connection main body portion 191 extending in the Z direction, a plurality of terminal connection portions 192, and a bus bar connection portion 193. The terminal connection portion 192 protrudes from the connection main body portion 191 toward the semiconductor module 7 in the Y direction. The pitch of the terminal connection portions 192 in the Z direction is equal to the pitch of the negative electrode terminals 70b in the Z direction. The terminal connection portion 192 and the negative electrode terminal 70b are overlapped and connected by welding or the like.

  In addition, the bus bar connection portion 193 protrudes toward the capacitor 1 from the end portion on the bottom portion 125 side of the connection main body portion 191 in the Z direction.

  Similarly to the first embodiment, the negative bus bar 3 b includes a negative connection plate portion 320, an inner extension portion 31, a connecting portion 34, an outer extension portion 32, and a protrusion 35. The projecting portion 35 and the bus bar connecting portion 193 of the connecting member 19b are overlapped and welded to connect them.

  Further, the positive bus bar 3a and the positive terminal 70a are connected via a connecting member 19 (19a). The positive side bus bar 3a has the same structure as that of the first embodiment except that the positive side module connection plate 316 is not provided. The connecting member 19a has substantially the same structure as the connecting member 19b of the negative electrode terminal 70b described above. The bus bar connecting portion 193 (see FIG. 12) formed on the connecting member 19a and the projecting portion 35a of the positive bus bar 3a are overlapped and welded to connect them.

  The effect of this example will be described. In this example, the semiconductor module 7 is disposed adjacent to the capacitor 1, and the power terminal 70 of the semiconductor module 7 protrudes toward the capacitor 1 side. Therefore, the distance between the capacitor 1 and the power terminal 70 can be shortened. Thereby, the length of the bus bar 3 can be shortened, and the floating inductance of the bus bar 3 can be further reduced.

  Others are the same as in the first embodiment. Moreover, among the symbols used in the drawings relating to this example, the same symbols as those used in the first embodiment represent the same components as in the first embodiment unless otherwise indicated.

Example 4
In this example, a plurality of capacitors 1 are combined into one. In this example, as shown in FIG. 13, four capacitor elements 2 (2 a to 2 d) are housed in one case 4. Of these four capacitor elements 2, two capacitor elements 2 (2a, 2b) constitute a smoothing capacitor 1a, and the other two capacitor elements 2 (2c, 2d) constitute a filter capacitor 1b. Yes. As shown in FIG. 14, the power conversion device 10 of this example uses the two capacitors 1. The filter capacitor 1b is provided to remove noise from the DC voltage of the DC power supply 8. The smoothing capacitor 1a is provided to smooth the voltage boosted by the booster circuit 88.

  As shown in FIG. 13, a pair of bus bars 3 (a positive bus bar 3a and a negative bus bar 3b) are connected to the capacitor elements 2a and 2b for the smoothing capacitor 1a. Similarly, a pair of bus bars 3 (positive bus bar 3c, negative bus bar 3d) are also connected to the capacitor elements 2c and 2d for the filter capacitor 1b. These bus bars 3 have the same structure as the bus bar 3 in the first embodiment.

  In the smoothing capacitor 1a, the bus bar facing portion 6 (6a) is formed by the inner extending portion (not shown) and the outer extending portion 32b of the negative bus bar 3b. Moreover, the outer side extension part 32b of the negative side bus bar 3b and the outer side extension part 32a of the positive side bus bar 3a are adjacently arranged. The directions of the current I flowing through the two outer extending portions 32a and 32b are opposite to each other. Therefore, the stray inductance between the two outer extending portions 32a and 32b can be reduced.

  Also, the positive side bus bar 3c and the negative side bus bar 3d for the filter capacitor 1b have the same configuration as the bus bars 3a and 3b for the smoothing capacitor 1a.

  Although not shown, the negative side bus bar 3b of the smoothing capacitor 1a and the positive side bus bar 3c of the filter capacitor 1b may be arranged adjacent to each other in the X direction. These bus bars 3b and 3c have opposite directions of flowing current. Therefore, when these are arranged adjacent to each other, it becomes possible to reduce the stray inductance between the bus bars 3b and 3c.

  Others are the same as in the first embodiment. Moreover, among the symbols used in the drawings relating to this example, the same symbols as those used in the first embodiment represent the same components as in the first embodiment unless otherwise indicated.

DESCRIPTION OF SYMBOLS 1 Capacitor 2 Capacitor element 3 Bus bar 4 Case 5 Sealing member 6 Bus bar opposing part

Claims (5)

A capacitor element (2);
A case (4) for housing the capacitor element (2);
A pair of bus bars (3, 3a, 3b) electrically connected to the capacitor element (2);
A sealing member (5) for sealing the capacitor element (2) and the pair of bus bars (3) in the case (4);
A bus bar facing portion (6) in which a part of the bus bar (3) is opposed to one bus bar (3) or between the pair of bus bars (3a, 3b) is formed.
The bus bar facing portion (6) is formed on the bus bar (3), and extends in the case (4) along the side wall (40) of the case (4). An outer extending portion (32) formed on the bus bar (3) and extending along the side wall (40) outside the case (4) is disposed so as to face the side wall (40). Capacitor (1), wherein the directions of currents flowing in the inner extension (31) and the outer extension (32) are opposite to each other.   The capacitor (1) according to claim 1, wherein the bus bar facing portion (6) is formed by bending one bus bar (3).   3. The capacitor (1) according to claim 2, wherein the pair of bus bars (3 a, 3 b) are formed with the outer extending portions (32), respectively, and the pair of outer extending portions (32) are arranged adjacent to each other. A capacitor (1) characterized in that   The capacitor (1) according to any one of claims 1 to 3, wherein the length of the bus bar facing portion (6) in the normal direction of the bottom surface of the case is equal to the capacitor element (2 in the normal direction). The capacitor (1) characterized by being longer than the length of).   A power converter (10) comprising the capacitor (1) according to any one of claims 1 to 4 and a semiconductor module (7) incorporating a semiconductor element (73), wherein the semiconductor module (7 ) Is disposed adjacent to the capacitor (1), the power terminal (70) of the semiconductor module (7) protrudes toward the capacitor (1), and the pair of bus bars (3) are connected to the power terminal (70). The power converter device (10) characterized by being connected to.

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