Power conversion device and motor module

Abstract

The present invention comprises: a capacitor module having a capacitor element and a case part for accommodating the capacitor element; a power module having a power semiconductor element for performing power conversion; a control board for driving the power module; and a bus bar module having a bus bar. The capacitor element has a capacitor body part and a first connection terminal extending from the capacitor body part to one side in a first direction. The power module has a second connection terminal. The bus bar electrically connects the first connection terminal and the second connection terminal. The case part has: a first housing part which is recessed from one side in the first direction to the other side in the first direction and accommodates the capacitor body part; and a first flow path through which a refrigerant flows.

Description

Power conversion device and motor module

[0001] The present invention relates to a power conversion device and a motor module.

[0002] As an example of a power conversion device that supplies power to a motor, there has been disclosed a power conversion device that includes a power module unit having a power semiconductor, a capacitor unit having a capacitor element, and a refrigerant flow path through which a refrigerant that cools the capacitor element flows, and in which the power module unit and the capacitor element are electrically connected by a bus bar (for example, Japanese Patent Laid-Open Publication No. 2013-031330).

[0003] Japanese Patent Publication No. 2013-031330

[0004] In the power conversion device described in Patent Document 1, a bus bar is disposed between the capacitor element and the refrigerant flow path, which tends to increase the thermal resistance between the capacitor element and the refrigerant flow path. This makes it difficult to increase the amount of heat transferred from the capacitor element to the refrigerant flowing through the refrigerant flow path, which can lead to excessive temperature rise of the capacitor element. This can accelerate the deterioration of the capacitor element.

[0005] In view of the above circumstances, one aspect of the present invention aims to provide a power conversion device and a motor module that can prevent the temperature of a capacitor element from becoming too high.

[0006] One aspect of the power conversion device of the present invention includes a capacitor module having a capacitor element and a case portion that houses the capacitor element, a power module having power semiconductor elements that perform power conversion, a control board that drives the power semiconductor elements, and a bus bar module having bus bars. The capacitor element has a capacitor body portion and a first connection terminal extending from the capacitor body portion to one side in a first direction. The power module has a second connection terminal. The bus bar electrically connects the first connection terminal and the second connection terminal. The case portion is recessed from one side in the first direction to the other side in the first direction, and has a first housing portion that houses the capacitor body portion and a first flow path through which a refrigerant flows.

[0007] One aspect of a motor module of the present invention includes the above-described power conversion device and a motor driven by current supplied from the power conversion device.

[0008] According to one aspect of the present invention, in a power conversion device and a motor module, it is possible to prevent the temperature of a capacitor element from becoming too high.

[0009] Fig. 1 is a perspective view showing a motor module of a first embodiment. Fig. 2 is a perspective view showing a portion of the motor module of the first embodiment. Fig. 3 is a cross-sectional view showing a portion of the power conversion device of the first embodiment. Fig. 4 is a cross-sectional view showing a portion of the power conversion device of the first embodiment, taken along line IV-IV in Fig. 3. Fig. 5 is a cross-sectional view showing a portion of the power conversion device of a second embodiment.

[0010] Hereinafter, a power conversion device according to an embodiment of the present invention will be described with reference to the drawings. Note that the scope of the present invention is not limited to the following embodiments and can be modified as desired within the scope of the technical concept of the present invention. In addition, in the following drawings, the scale and number of components may differ from the actual structure in order to make each component easier to understand.

[0011] <First embodiment> In the following description, a first direction D1 is shown in each figure as appropriate. In this embodiment, the first direction D1 is the up-down direction of the power conversion device 10. In the following description, the side toward which the arrow of the first direction D1 points (+D1 side) is referred to as "one side of the first direction D1" or "upper side." The side opposite to the side toward which the arrow of the first direction D1 points (-D1 side) is referred to as "the other side of the first direction D1" or "lower side."

[0012] In the following description, the second direction D2 is shown in each figure as appropriate. In this embodiment, the second direction D2 is the left-right direction of the power conversion device 10. The second direction D2 intersects with the first direction D1. In this embodiment, the second direction D2 is perpendicular to the first direction D1. In the following description, the side toward which the arrow of the second direction D2 points (+D2 side) is referred to as the "left side." The side opposite to the side toward which the arrow of the second direction D2 points (-D2 side) is referred to as the "right side."

[0013] In the following description, the third direction D3 is shown in each figure as appropriate. The third direction D3 is a direction perpendicular to both the first direction D1 and the second direction D2. The third direction D3 is the front-to-rear direction of the power conversion device 10. In the following description, the side toward which the arrow of the third direction D3 points (+D3 side) is referred to as the "front side." The side opposite to the side toward which the arrow of the third direction D3 points (-D3 side) is referred to as the "rear side."

[0014] Note that the terms upper, lower, left, right, front, and rear are simply names used to describe the relative positional relationships of each part, and the actual positional relationships may be other than those indicated by these names.

[0015] FIG. 1 is a perspective view showing a motor module 90 of this embodiment. The motor module 90 includes a power conversion device 10 and a motor 91. The motor 91 is a drive device that is mounted on, for example, a vehicle and rotates the axle of the vehicle. The motor 91 is driven by current supplied from the power conversion device 10. The vehicle on which the motor module 90 is mounted is a vehicle that uses the motor 91 as a power source, such as a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHV), or an electric vehicle (EV).

[0016] The power conversion device 10 supplies a current to the motor 91. The power conversion device 10 generates a current to be supplied to the motor 91, and supplies the current to each of a U-phase coil, a V-phase coil, and a W-phase coil of the motor 91. As shown in FIG. 2 , the power conversion device 10 includes a housing 11, a holding portion 21, a power module 24, a control board 25, a bus bar module 30, a capacitor module 40, and a refrigerant flow path 60.

[0017] The housing 11 accommodates the components that make up the power conversion device 10, such as the holding portion 21, the power module 24, the control board 25, the bus bar module 30, and the capacitor module 40. As shown in Fig. 1 , the housing 11 has a substantially rectangular box shape. When viewed from a first direction D1, the housing 11 has a substantially rectangular shape with its long sides extending in a second direction D2. The housing 11 has a first housing 12 and a second housing 13.

[0018] As shown in FIG. 2 , the first housing 12 is box-shaped and open on the upper side (−D3 side). The first housing 12 has a peripheral wall portion 12a and a bottom wall portion 12b. As shown in FIG. 1 , the peripheral wall portion 12a is rectangular and tubular, protruding in the first direction D1. The peripheral wall portion 12a surrounds the holding portion 21, the power module 24, the control board 25, the busbar module 30, and the capacitor module 40 in the second direction D2 and the third direction D3. The first and fourth conduits 61 and 66, which extend in the third direction D3, are provided in the wall portion of the peripheral wall portion 12a located on the front side (+D3 side) and extending in the second direction D2.

[0019] The first pipe 61 is disposed to the right (−D2 side) of the fourth pipe 66. The front (+D3 side) portions of the first pipe 61 and the fourth pipe 66 protrude forward from the peripheral wall 12a. A supply pipe 71 is connected to the front end of the first pipe 61. A discharge pipe 72 is connected to the front end of the fourth pipe 66. As shown in FIG. 2 , the rear (−D3 side) portions of the first pipe 61 and the fourth pipe 66 protrude rearward from the peripheral wall 12a. Although not shown, the rear end of the first pipe 61 is connected to the capacitor module 40. The rear end of the fourth pipe 66 is connected to the holder 21. A refrigerant L flows through the first pipe 61 and the fourth pipe 66.

[0020] The bottom wall portion 12b has a plate shape that extends in a direction perpendicular to the first direction D1. The plate surface of the bottom wall portion 12b faces the first direction D1. The outer edge of the bottom wall portion 12b is connected to the lower end of the peripheral wall portion 12a.

[0021] 1 is a box-shaped body that is open on the lower side (−D1 side). The second housing 13 is fixed to the upper end of the first housing 12.

[0022] 3, the holding portion 21 holds the power module 24. The holding portion 21 is disposed below (on the −D1 side of) the power module 24. The power module 24 is fixed to the upper end of the holding portion 21. The holding portion 21 has a holding case 22 and a heat sink 23.

[0023] As shown in Fig. 4, the holding case 22 has a generally rectangular parallelepiped shape extending in the third direction D3. As shown in Fig. 3, two surfaces of the holding case 22 face the first direction D1, and the other two surfaces of the holding case 22 face the second direction D2. The holding case 22 is provided with a first recess 22a, a second recess 22b, a third hole 22c, and a fourth hole 22d.

[0024] The first recess 22a is recessed downward from the surface of the holding case 22 facing upward (+D1 side). As shown in Fig. 4, the first recess 22a is generally rectangular when viewed from the first direction D1. As shown in Fig. 3, the second recess 22b is recessed downward from the surface of the holding case 22 facing upward. Although not shown, when viewed from the first direction D1, the second recess 22b has a generally rectangular ring shape with its long sides extending in the third direction D3. The second recess 22b surrounds the first recess 22a from the outside in both the second direction D2 and the third direction D3.

[0025] As shown in FIG. 4 , the third hole 22c is a hole that is located on the rear side (−D3 side) of the wall of the holding case 22 and penetrates the wall extending in the second direction D2 in the third direction D3. The outside of the holding case 22 is connected to the interior of the first recess 22a via the third hole 22c. A third conduit 64 is connected to the third hole 22c. The fourth hole 22d is located on the front side (+D3 side) of the wall of the holding case 22 and penetrates the wall extending in the second direction D2 in the third direction D3. The outside of the holding case 22 is connected to the interior of the first recess 22a via the fourth hole 22d. A fourth conduit 66 is connected to the fourth hole 22d.

[0026] 3 transfers heat generated in the power module 24 to the coolant L flowing inside the first recess 22a of the holding case 22. In this embodiment, the heat sink 23 is made of a metal material such as copper or aluminum. The heat sink 23 has a main body 23a, a fixing portion 23b, and a plurality of fins 23c.

[0027] The main body 23a has a plate shape that extends in a direction perpendicular to the first direction D1. The plate surface of the main body 23a faces the first direction D1. The main body 23a closes the first recess 22a from above (the +D1 side). The power module 24 is fixed to the surface of the main body 23a facing upward. In this way, the holding portion 21 holds the power module 24.

[0028] The fixing portion 23b protrudes downward from the outer edge of the main body portion 23a. Although not shown, when viewed from the first direction D1, the fixing portion 23b has a generally rectangular ring shape with its long sides extending in the third direction D3. The fixing portion 23b is disposed inside the second recess 22b. The fixing portion 23b is fixed to the inner surface of the second recess 22b. This fixes the heat sink 23 to the holding case 22. A sealing member 81 is disposed between the inner circumferential surface of the fixing portion 23b and the inner surface of the second recess 22b. The sealing member 81 contacts both the inner circumferential surface of the fixing portion 23b and the inner surface of the second recess 22b. This allows the sealing member 81 to seal between the heat sink 23 and the holding case 22.

[0029] Each of the multiple fin portions 23c protrudes downward from the main body portion 23a. Each fin portion 23c is disposed inside the first recess 22a. As shown in FIG. 4 , in this embodiment, each fin portion 23c is disposed at intervals from one another along each of the second direction D2 and the third direction D3. Each fin portion 23c may be disposed at intervals from one another along only one of the second direction D2 or the third direction D3. As shown in FIG. 3 , in this embodiment, each fin portion 23c is disposed at intervals from a surface of the first recess 22a facing the upper side (+D1 side) in the first direction D1. Each fin portion 23c may be in contact with the surface of the first recess 22a facing the upper side. Note that the heat sink 23 does not necessarily have fin portions 23c.

[0030] The holding portion 21 is provided with a second flow path 65 through which the coolant L flows. The second flow path 65 is formed by the inner surface of the first recess 22a, the downward surface of the main body portion 23a, and the outer surfaces of each fin portion 23c. Each fin portion 23c protrudes into the second flow path 65. Each fin portion 23c comes into contact with the coolant L flowing through the second flow path 65.

[0031] The power module 24 generates a current of a predetermined waveform from a current supplied by an external power supply (not shown) and supplies the generated current to the motor 91. More specifically, the power conversion device 10 generates phase currents (U-phase current, V-phase current, and W-phase current) to be supplied to U-phase coils, V-phase coils, and W-phase coils (not shown) of the motor 91, respectively. In this embodiment, the power conversion device 10 is an inverter that converts DC current into AC current. The power module 24 has a power semiconductor element 24c and a second connection terminal 26.

[0032] The power semiconductor elements 24c generate a current with a predetermined waveform from a current supplied by an external power supply (not shown). The power semiconductor elements 24c thereby perform power conversion. In the present embodiment, the power semiconductor elements 24c convert DC current into AC current, for example. In the present embodiment, the power semiconductor elements 24c are electronic elements such as metal-oxide semiconductor field-effect transistors (MOSFETs) and insulated gate bipolar transistors (IGBTs). The power module 24 includes a plurality of power semiconductor elements 24c. Although not shown, in the present embodiment, the power module 24 includes six power semiconductor elements 24c. Each of a pair of power semiconductor elements 24c generates one of a U-phase current, a V-phase current, and a W-phase current.

[0033] The second connection terminals 26 electrically connect the power semiconductor elements 24c arranged inside the power module 24 to the bus bar module 30. The second connection terminals 26 are plate-shaped and protrude from the power module 24 to the right (−D2 side). The plate surface of the second connection terminals 26 faces the first direction D1. The second connection terminals 26 are made of metal. In this embodiment, the power module 24 has six second connection terminals 26. The six second connection terminals 26 include three second positive terminals 26a and three second negative terminals 26b.

[0034] The second positive terminals 26a are spaced apart from each other in the third direction D3. Each second positive terminal 26a is electrically connected to a different pair of power semiconductor elements 24c. The second negative terminals 26b are spaced apart from each other in the third direction D3. When viewed from the first direction D1, each second negative terminal 26b is positioned offset from the second positive terminal 26a in the third direction D3. As shown in FIG. 3 , each second negative terminal 26b is positioned above (on the +D1 side of) the second positive terminal 26a. Each second negative terminal 26b is electrically connected to a different pair of power semiconductor elements 24c.

[0035] The output terminal 95 shown in FIG. 2 is a path through which current generated by the power semiconductor element 24c flows. The output terminal 95 is plate-shaped and protrudes to the left (+D2 side) from the power module 24. The output terminal 95 is made of metal. Although not shown, the right end (+D2 side) of the output terminal 95 is electrically connected to the power semiconductor element 24c of the power module 24. Furthermore, the left end of the output terminal 95 is connected to a terminal connected to the coil of the motor 91. This allows a phase current to be supplied from the power module 24 to the coil of the motor 91. In this embodiment, the power module 24 has three output terminals 95. The output terminals 95 are arranged side by side in the third direction D3. Each output terminal 95 receives one of a U-phase current, a V-phase current, and a W-phase current.

[0036] The control board 25 is a printed circuit board extending in a direction perpendicular to the first direction D1. When viewed from the first direction D1, the control board 25 has a generally rectangular shape with its long sides extending in the third direction D3. The control board 25 drives the power semiconductor elements 24c. Although not shown, multiple electronic elements such as integrated circuits (ICs) and resistors are mounted on the control board 25. As shown in FIG. 3 , the control board 25 is disposed above the heat sink 23 (on the +D1 side). The control board 25 is supported in the first direction D1 by multiple connection pins 24d. Each connection pin 24d is conductive. Each connection pin 24d electrically connects the power module 24 and the control board 25. This electrically connects each power semiconductor element 24c to the control board 25. The control board 25 controls the power conversion of the power module 24 by providing control pulses to each power semiconductor element 24c.

[0037] In this embodiment, the bus bar module 30 is disposed to the right (−D2 side) of the power module 24 and above (+D1 side) the capacitor module 40. The bus bar module 30 includes a first holding member 31 and a plurality of bus bars 33.

[0038] Although not shown, the first holding member 31 has a generally rectangular parallelepiped shape extending in the third direction D3. Two faces of the first holding member 31 face the first direction D1, and the other two faces of the first holding member 31 face the second direction D2. In this embodiment, the first holding member 31 is made of resin and has insulating properties. In this embodiment, the first holding member 31 is molded by insert molding using a plurality of bus bars 33 as insert members. In this way, the first holding member 31 holds each bus bar 33. The first holding member 31 is provided with a first through hole 31a and a second through hole 31b.

[0039] The first through hole 31a and the second through hole 31b each penetrate the first holding member 31 in the first direction D1. The first through hole 31a is located to the left (+D2 side) of the second through hole 31b. As shown in FIG. 2 , the first through hole 31a has a substantially rectangular shape when viewed from the first direction D1. In this embodiment, three first through holes 31a are provided in the first holding member 31. The first through holes 31a are spaced apart from one another along the third direction D3. The second through hole 31b has a substantially rectangular shape when viewed from the first direction D1. In this embodiment, three second through holes 31b are provided in the first holding member 31. The second through holes 31b are spaced apart from one another along the third direction D3. When viewed from the second direction D2, each second through hole 31b is provided at a position shifted in the third direction D3 from the first through holes 31a.

[0040] 3 , the plurality of bus bars 33 electrically connect the power module 24 and the capacitor module 40. Each bus bar 33 is a plate-shaped member. The plurality of bus bars 33 includes a first bus bar 34 and a second bus bar 35.

[0041] The first bus bar 34 has a first main body portion 34a and a first protrusion portion 34b. The first main body portion 34a is held by the surface of the first holding member 31 facing the upper side (+D1 side). As shown in FIG. 2, the first main body portion 34a is plate-shaped and extends in a direction perpendicular to the first direction D1. The front end (+D3 side) of the first main body portion 34a is located forward of the frontmost second connection terminal 26 and is electrically connected to the cathode side of an external power supply (not shown). As shown in FIG. 3, the left side (+D2 side) of the first main body portion 34a is fixed to each second negative terminal 26b by a bolt 82. This electrically connects the first bus bar 34 to each second negative terminal 26b. Holes 34d are formed in the first main body portion 34a.

[0042] The hole 34d is a hole that penetrates the first main body portion 34a in the first direction D1. As shown in FIG. 2, the hole 34d has a substantially rectangular shape when viewed from the first direction D1. In this embodiment, three hole portions 34d are provided in the first main body portion 34a. The hole portions 34d are provided at intervals from each other along the third direction D3. When viewed from the first direction D1, the hole portions 34d surround different first through holes 31a.

[0043] As shown in Fig. 3, the first protrusion 34b is a plate-like member that protrudes upward (towards +D1) from the right end (-D2 side) of the first main body portion 34a. The plate surface of the first protrusion 34b faces the second direction D2. As shown in Fig. 2, the first bus bar 34 has three first protrusions 34b. The first protrusions 34b are spaced apart from one another along the third direction D3.

[0044] As shown in FIG. 3 , the second bus bar 35 has a second main body portion 35a and a second protrusion portion 35b. The second main body portion 35a passes through the first holding member 31 in the second direction D2. The second main body portion 35a is plate-shaped and extends in a direction perpendicular to the first direction D1. Although not shown, the front end (+D3 side) of the second main body portion 35a is located forward of the frontmost second connection terminal 26 and is electrically connected to the positive side of an external power supply (not shown). The left side (+D2 side) of the second main body portion 35a is fixed to each second positive terminal 26a by a bolt 82. This electrically connects the second bus bar 35 to each second positive terminal 26a. As described above, the first bus bar 34 is electrically connected to each second negative terminal 26b. As a result, the bus bar 33 is electrically connected to the second connection terminal 26.

[0045] The second protrusion 35b is a plate-like member that protrudes upward (toward +D1) from the right end (-D2 side) of the second main body 35a. The plate surface of the second protrusion 35b faces the second direction D2. As shown in FIG. 2, the second bus bar 35 has three second protrusions 35b. The second protrusions 35b are spaced apart from one another along the third direction D3. As shown in FIG. 3, the second protrusions 35b pass through different first through holes 31a and holes 34d in the first direction D1. The upper ends of the second protrusions 35b are located above the first main body 34a.

[0046] In this embodiment, the capacitor module 40 is disposed below (on the −D1 side of) the bus bar module 30. The capacitor module 40 has a case portion 41 and a capacitor element 50. The case portion 41 houses the capacitor element 50. The case portion 41 has a first case portion 42, a second case portion 45, and a first flow path 62.

[0047] As shown in Fig. 4, the first case portion 42 has a generally rectangular parallelepiped shape extending in the third direction D3. As shown in Fig. 3, two faces of the first case portion 42 face the first direction D1, and the other two faces of the first case portion 42 face the second direction D2. In this embodiment, the first case portion 42 is made of metal. The first case portion 42 is provided with a first storage portion 42a and a plurality of protrusions 42c.

[0048] The first housing portion 42a is recessed downward from the upper side of the first case portion 42, i.e., from the surface facing one side (+D1 side) in the first direction D1, i.e., from the other side (-D1 side) in the first direction D1. As shown in FIG. 4 , when viewed from the first direction D1, the first housing portion 42a has a generally rectangular shape with its long side extending in the third direction D3. In this embodiment, three first housing portions 42a are provided in the first case portion 42. The first housing portions 42a are provided at intervals from one another along the third direction D3.

[0049] As shown in FIG. 3 , each of the multiple protrusions 42c protrudes downward from the first case portion 42. In this embodiment, the protrusions 42c are heat dissipation fins. Although not shown, in this embodiment, the protrusions 42c are arranged at intervals from one another along each of the second direction D2 and the third direction D3. The protrusions 42c may also be arranged at intervals from one another along only either the second direction D2 or the third direction D3. The protrusions 42c protrude into the first flow path 62. Note that the first case portion 42 does not necessarily have to be provided with the protrusions 42c.

[0050] As shown in Fig. 4, the second case portion 45 has a generally rectangular parallelepiped shape extending in the third direction D3. As shown in Fig. 3, two surfaces of the second case portion 45 face the first direction D1, and the other two surfaces of the second case portion 45 face the second direction D2. The second case portion 45 is provided with a second storage portion 45a, a first hole 45e, and a second hole 45f.

[0051] The second housing portion 45a is a recess recessed downward (toward the -D1 side) from the surface of the second case portion 45 facing the upper side (+D1 side). As shown in FIG. 4, when viewed from the first direction D1, the second housing portion 45a has a generally rectangular shape with its long sides extending in the third direction D3. As shown in FIG. 3, the first case portion 42 is housed inside the second housing portion 45a. The lower end of the second housing portion 45a is located lower than the lower end of the first case portion 42. In this embodiment, the second case portion 45 is made of resin. In this embodiment, the second case portion 45 is molded by insert molding using the first case portion 42 as an insert member. As a result, the first case portion 42 is fixed to the inner surface of the second housing portion 45a.

[0052] As shown in Fig. 4, the first hole 45e is located on the front side (+D3 side) of the wall of the second case portion 45, and is a hole that penetrates the wall portion extending in the second direction D2 in the third direction D3. As shown in Fig. 3, the first hole 45e is provided below (-D1 side) the first case portion 42. As shown in Fig. 4, the first pipe 61 is connected to the first hole 45e.

[0053] The second hole 45f is a hole that is disposed on the rear side (-D3 side) of the wall of the second case portion 45 and penetrates the wall portion extending in the second direction D2 in the third direction D3. As shown in Fig. 3, the second hole 45f is provided below (-D1 side) the first case portion 42. As shown in Fig. 4, the second pipe 63 is connected to the second hole 45f.

[0054] The first flow path 62 is a flow path through which the refrigerant L flows. As shown in Fig. 3, the first flow path 62 is defined by the outer surface of the first case portion 42 and the inner surface of the second storage portion 45a. The first flow path 62 is connected to the outside of the second case portion 45 via the first hole portion 45e. The first flow path 62 is connected to the outside of the second case portion 45 via the second hole portion 45f.

[0055] The capacitor element 50 serves as a smoothing capacitor that smoothes the current supplied to the power module 24 from an external power supply (not shown). As shown in FIG. 4 , in this embodiment, the capacitor module 40 has a plurality of capacitor elements 50. In this embodiment, the capacitor module 40 has three capacitor elements 50. The number of capacitor elements 50 included in the capacitor module 40 may be two or less, or may be four or more. As shown in FIG. 3 , each capacitor element 50 has a capacitor body 51 and a first connection terminal 52.

[0056] The capacitor body 51 has a substantially rectangular parallelepiped shape. As shown in FIGS. 3 and 4 , each capacitor body 51 is housed inside a different first housing portion 42a. In this embodiment, the capacitor elements 50 are arranged at intervals along the direction in which the first flow path 62 extends (third direction D3). Each capacitor body 51 is fixed to the inner surface of the first housing portion 42a. This allows the case portion 41 to hold multiple capacitor elements 50. The outer surface of each capacitor body 51 is made of an insulating material, such as resin. This makes the outer surface of each capacitor body 51 insulating.

[0057] 3 , the first connection terminal 52 electrically connects the capacitor body 51 and the bus bar 33. The first connection terminal 52 extends upward from the capacitor body 51, i.e., toward one side (+D1 side) in the first direction D1. The first connection terminal 52 is conductive. In this embodiment, each capacitor element 50 has two first connection terminals 52. The two first connection terminals 52 include a first positive terminal 52 a and a first negative terminal 52 b.

[0058] The first positive terminals 52a of each capacitor element 50 pass through different first through holes 31a in the first direction D1. The first positive terminals 52a are fixed to different second protrusions 35b of the second bus bar 35. This electrically connects each capacitor element 50 to the second bus bar 35. The first negative terminals 52b are disposed to the right (-D3 side) of the first positive terminals 52a. The first negative terminals 52b of each capacitor element 50 pass through different second through holes 31b in the first direction D1. The first negative terminals 52b are fixed to different first protrusions 34b of the second bus bar 35. This electrically connects each capacitor element 50 to the first bus bar 34. As described above, each capacitor element 50 is electrically connected to the second bus bar 35. As a result, the bus bar 33 is electrically connected to the first connection terminals 52 of each capacitor element 50. As described above, the bus bar 33 is electrically connected to the second connection terminal 26. Therefore, the bus bar 33 electrically connects the first connection terminal 52 and the second connection terminal 26. In the present embodiment, the first connection terminal 52 and the bus bar 33 are fixed by welding. The first connection terminal 52 and the bus bar 33 may also be fixed by a fastening member such as a bolt.

[0059] The refrigerant flow path 60 shown in FIG. 4 is a flow path that supplies the refrigerant L to the first flow path 62 and the second flow path 65. The refrigerant flow path 60 is provided with a pump and a cooler (not shown). The pump pumps the refrigerant L. The cooler cools the refrigerant L. In this embodiment, the refrigerant L is a liquid such as water or oil. The refrigerant flow path 60 includes a first pipe 61, a first flow path 62, a second pipe 63, a third pipe 64, a second flow path 65, and a fourth pipe 66. In this embodiment, the first pipe 61, the second pipe 63, the third pipe 64, and the fourth pipe 66 are each a pipe. In this embodiment, the refrigerant L flows through the first pipe 61, the first flow path 62, the second pipe 63, the third pipe 64, the second flow path 65, and the fourth pipe 66 in this order. The refrigerant L may flow through the fourth pipe 66, the second flow path 65, the third pipe 64, the second pipe 63, the first flow path 62, and the first pipe 61 in this order.

[0060] The first conduit 61 is fixed to the first hole 45e. As a result, the first conduit 61 is connected to the first flow path 62 via the first hole 45e. The first flow path 62 connects the first conduit 61 and the second conduit 63. In the first flow path 62, the refrigerant L flows from the front side (+D3 side) to the rear side (-D3 side). As shown in FIG. 3, each protrusion 42c provided on the first case portion 42 protrudes into the first flow path 62. Each protrusion 42c comes into contact with the refrigerant L flowing through the first flow path 62. This increases the contact area between the refrigerant L flowing through the first flow path 62 and the first case portion 42.

[0061] As shown in FIG. 4 , the second conduit 63 connects the first flow path 62 and the third conduit 64. One end of the second conduit 63 is fixed to the second hole 45f. As a result, the second conduit 63 is connected to the first flow path 62 via the second hole 45f. The other end of the second conduit 63 is connected to one end of the third conduit 64. The third conduit 64 connects the second conduit 63 and the second flow path 65. The other end of the third conduit 64 is fixed to the third hole 22c. As a result, the third conduit 64 is connected to the second flow path 65 via the third hole 22c.

[0062] The second flow path 65 connects the third pipeline 64 and the fourth pipeline 66. In the second flow path 65, the refrigerant L flows from the rear side (-D3 side) to the front side (+D3 side). As described above, each of the multiple fin portions 23c of the heat sink 23 protrudes into the second flow path 65. Each fin portion 23c comes into contact with the refrigerant L flowing through the second flow path 65. This increases the contact area between the refrigerant L flowing through the second flow path 65 and the heat sink 23. The fourth pipeline 66 is fixed to the fourth hole portion 22d. This connects the fourth pipeline 66 to the second flow path 65. The refrigerant L that flows from the second flow path 65 into the fourth pipeline 66 is discharged to the outside of the power conversion device 10.

[0063] According to this embodiment, the power conversion device 10 includes a capacitor module 40 having a capacitor element 50 and a case portion 41 that houses the capacitor element 50, a power module 24 having a power semiconductor element 24c that performs power conversion, a control board 25 that drives the power module 24, and a bus bar module 30 having a bus bar 33. The capacitor element 50 has a capacitor body portion 51 and a first connection terminal 52 extending upward from the capacitor body portion 51, i.e., toward one side (+D1 side) in the first direction D1, the power module 24 has a second connection terminal 26, and the bus bar 33 electrically connects the first connection terminal 52 to the second connection terminal 26. The case portion 41 is recessed from the upper side to the lower side, i.e., toward the other side (-D1 side) in the first direction D1, and has a first housing portion 42a that houses the capacitor body portion 51 and a first flow path 62 through which the refrigerant L flows. Therefore, because the case 41 in which the capacitor body 51 is housed has the first flow path 62, the thermal resistance between the capacitor element 50 and the first flow path 62 can be reduced compared to when the first flow path 62 is provided in a member different from the case 41. This increases the amount of heat transferred from the capacitor element 50 to the refrigerant L flowing through the first flow path 62. This prevents the temperature of the capacitor element 50 from becoming too high. This prevents the capacitor element 50 from deteriorating.

[0064] Furthermore, in the present embodiment, since the first flow path 62 is provided in the case portion 41, the shape and configuration of the housing 11 can be simplified compared to when the first flow path 62 is provided in the housing 11. This makes it possible to prevent an increase in the manufacturing cost of the housing 11. Therefore, it is possible to prevent an increase in the manufacturing cost of the power conversion device 10.

[0065] For example, if the capacitor element 50 and the bus bar 33 are electrically connected and then integrated by insert molding, the number of parts to be inserted increases, which tends to increase the number of steps required to manufacture the integrated unit. In contrast, in the present embodiment, the capacitor module 40 and the bus bar module 30 can be manufactured separately, and then the capacitor element 50 and the bus bar 33 can be electrically connected. This makes it easy to reduce the number of parts required for the insert members of each module 30, 40. Therefore, it is easy to prevent an increase in the number of steps required to manufacture each module 30, 40, and therefore it is possible to prevent an increase in the number of steps required to manufacture the power conversion device 10.

[0066] Furthermore, in this embodiment, in the manufacturing process of the power conversion device 10, the capacitor module 40, the bus bar module 30, and the power module 24 can be manufactured in parallel, which makes it easier to more effectively prevent an increase in the number of manufacturing steps for the power conversion device 10.

[0067] According to this embodiment, the case portion 41 includes a first case portion 42 having a first housing portion 42a and a second case portion 45 having a second housing portion 45a that houses the first case portion 42. The first flow path 62 is formed by the outer surface of the first case portion 42 and the inner surface of the second case portion 45. This allows the refrigerant L flowing through the first flow path 62 to come into direct contact with the first case portion 42 that houses the capacitor body 51. This more effectively increases the amount of heat transferred from the capacitor element 50 to the refrigerant L flowing through the first flow path 62. This more effectively prevents the temperature of the capacitor element 50 from becoming too high. This more effectively prevents the capacitor element 50 from deteriorating.

[0068] According to this embodiment, the first case portion 42 is made of metal. Therefore, the thermal conductivity of the first case portion 42 can be increased compared to when the first case portion 42 is made of resin. This can more effectively increase the amount of heat transferred from the capacitor element 50 to the refrigerant L flowing through the first flow path 62. Therefore, it is possible to more effectively prevent the temperature of the capacitor element 50 from becoming too high.

[0069] According to this embodiment, the first case portion 42 is provided with a plurality of protrusions 42c that protrude into the first flow path 62. Therefore, as described above, it is possible to increase the contact area between the refrigerant L flowing through the first flow path 62 and the first case portion 42. This makes it possible to more suitably increase the amount of heat transferred from the capacitor element 50 to the refrigerant L flowing through the first flow path 62. Therefore, it is possible to more suitably prevent the temperature of the capacitor element 50 from becoming too high.

[0070] According to this embodiment, the second case portion 45 is made of resin and is formed by insert molding using the first case portion 42 as an insert member. Therefore, the case portion 41 is easy to manufacture, and an increase in the number of manufacturing steps and manufacturing costs of the capacitor module 40 can be suppressed.

[0071] The busbar module 30 has a plurality of busbars 33 and a first holding member 31 made of resin that holds the plurality of busbars 33. The first holding member 31 is molded by insert molding using the plurality of busbars 33 as insert members. This allows the busbar module 30 to be easily manufactured, thereby preventing an increase in the number of manufacturing steps and manufacturing costs for the busbar module 30.

[0072] The multiple bus bars 33 include a first bus bar 34 and a second bus bar 35 through which currents of approximately equal magnitude flow in opposite directions. In this embodiment, disposing a portion of the insulating first holding member 31 between the first bus bar 34 and the second bus bar 35 facilitates arranging the first bus bar 34 and the second bus bar 35 close to each other. Therefore, the mutual inductance generated by the current flowing through the first bus bar 34 and the current flowing through the second bus bar 35 acts to cancel out the self-inductance, thereby reducing the parasitic inductance generated in each bus bar 33. This prevents an increase in surge noise generated by the switching operation of the power semiconductor elements 24c of the power module 24. This prevents an increase in the size of a noise filter provided to remove noise generated in the power module 24. This prevents an increase in the size of the power conversion device 10 and an increase in the manufacturing cost of the power conversion device 10.

[0073] According to the present embodiment, the first connection terminals 52 and the bus bars 33 are fixed by welding. Therefore, compared to when the first connection terminals 52 and the bus bars 33 are fixed by fastening members such as bolts, no space is required for arranging the fastening members. This makes it easier to prevent the capacitor modules 40 and the bus bar modules 30 from becoming larger. This more effectively prevents the power conversion device 10 from becoming larger.

[0074] Furthermore, in the present embodiment, compared to when the first connection terminal 52 and the bus bar 33 are fixed to each other by fastening members such as bolts, a step of measuring the tightening torque of the fastening members is not required in the manufacturing process of the power conversion device 10. Therefore, an increase in the number of steps in manufacturing the power conversion device 10 can be more effectively suppressed.

[0075] Furthermore, when the first connection terminal 52 and the bus bar 33 are fixed together with a fastening member, if the tightening torque of the fastening member is too small, the contact resistance between the first connection terminal 52 and the bus bar 33 increases. This increases the amount of heat generated at the connection between the first connection terminal 52 and the bus bar 33. In contrast, in the present embodiment, as described above, the first connection terminal 52 and the bus bar 33 are fixed together by welding, which makes it easier to prevent an increase in contact resistance between the first connection terminal 52 and the bus bar 33. This makes it possible to prevent an increase in the amount of heat generated at the connection between the first connection terminal 52 and the bus bar 33.

[0076] According to this embodiment, the power conversion device 10 includes a holding unit 21 that holds the power module 24, and the holding unit 21 is provided with a second flow path 65 through which the coolant L flows. Therefore, compared to when the second flow path 65 is provided in a member different from the holding unit 21, the thermal resistance between the power module 24 and the second flow path 65 can be reduced. This makes it possible to increase the amount of heat transferred from the power module 24 to the coolant L flowing through the second flow path 65. Therefore, it is possible to prevent the temperature of the power module 24 from becoming too high.

[0077] Furthermore, in the present embodiment, since the second flow path 65 is provided in the holding portion 21, the shape and configuration of the housing 11 can be more suitably simplified compared to when the second flow path 65 is provided in the housing 11. This makes it possible to more suitably prevent an increase in the manufacturing cost of the housing 11. Therefore, it is possible to more suitably prevent an increase in the manufacturing cost of the power conversion device 10.

[0078] Second Embodiment In the following description, a first direction D1 is shown in FIG. 5 . In this embodiment, the first direction D1 is the left-right direction of the power electronics device 210. In the following description, the side toward which the arrow of the first direction D1 points (+D1 side) is referred to as "one side of the first direction D1" or "left side." The side opposite to the side toward which the arrow of the first direction D1 points (-D1 side) is referred to as "the other side of the first direction D1" or "right side."

[0079] In the following description, the second direction D2 is shown in FIG. 5. In this embodiment, the second direction D2 is the up-down direction of the power conversion device 210. The second direction D2 intersects with the first direction D1. In this embodiment, the second direction D2 is perpendicular to the first direction D1. In the following description, the side toward which the arrow of the second direction D2 points (+D2 side) is referred to as the "upper side." The side opposite to the side toward which the arrow of the second direction D2 points (-D2 side) is referred to as the "lower side."

[0080] In the following description, a third direction D3 is appropriately indicated in each drawing. As in the first embodiment described above, the third direction D3 is the front-to-rear direction of the power conversion device 210. Note that the terms upper side, lower side, left side, right side, front side, and rear side are simply names used to describe the relative positional relationships of the various components, and the actual positional relationships may be other than those indicated by these names.

[0081] 5 is a cross-sectional view showing a portion of a power conversion device 210 of a motor module 290 of this embodiment. The power conversion device 210 includes a housing 11 (not shown), a holding portion 221, a pair of power modules 24, a pair of control boards 25, a bus bar module 230, a capacitor module 240, and a refrigerant flow path 260. In the following description, components that are the same as those in the first embodiment described above are designated by the same reference numerals, and description thereof will be omitted.

[0082] The holding portion 221 holds the power modules 24. In the second direction D2, the holding portion 221 is disposed between the pair of power modules 24. The power modules 24 are fixed to the upper and lower ends of the holding portion 221. The holding portion 221 has a holding case 222 and a pair of heat sinks 23.

[0083] Although not shown, the holding case 222 has a generally rectangular parallelepiped shape extending in the third direction D3. Two faces of the holding case 222 face the first direction D1, and the other two faces of the holding case 222 face the second direction D2. The holding case 222 is provided with a first recess 222a, second recesses 22b, a third hole 22c, and a fourth hole 22d.

[0084] The first recess 222a is recessed downward from the surface of the holding case 222 facing upward (+D2 side). Although not shown, the first recess 222a has a substantially rectangular shape when viewed from the first direction D1. In this embodiment, the first recess 222a opens downward (toward the -D2 side). The second recess 22b is recessed downward from the surface of the holding case 222 facing upward. The second recess 222b is recessed upward from the surface of the holding case 222 facing downward. Although not shown, the second recesses 22b, 222b have a substantially rectangular ring shape with long sides extending in the third direction D3 when viewed from the first direction D1. The second recesses 22b, 222b surround the first recess 222a from the outside in both the second direction D2 and the third direction D3.

[0085] Each of the pair of heat sinks 23 transfers heat generated in the power module 24 to the refrigerant L flowing through the second flow path 265. One heat sink 223a is disposed above (on the +D2 side of) the holding case 222. The other heat sink 223b is disposed below (on the -D2 side of) the holding case 222. The shapes of the heat sinks 223a and 223b are plane-symmetrical with respect to each other, with a plane that is orthogonal to the second direction D2 and passes between the pair of heat sinks 223a and 223b as the plane of symmetry.

[0086] The fixing portion 23b of one heat sink 223a is disposed inside the second recess 22b and fixed to the inner surface of the second recess 22b. The fixing portion 23b of the other heat sink 223b is disposed inside the second recess 222b and fixed to the inner surface of the second recess 222b. In this way, the pair of heat sinks 23 are fixed to the holding case 222.

[0087] The fins 23c of one heat sink 223a protrude downward (towards -D2) from the main body 23a. The fins 23c of the other heat sink 223b protrude upward (towards +D2) from the main body 23a. Each fin 23c is disposed inside the first recess 222a.

[0088] The holding portion 221 is provided with a second flow path 265 through which the refrigerant L flows. In this embodiment, the second flow path 265 is formed by the inner surface of the first recess 222a, the downward-facing surface of the main body 23a of one heat sink 223a, the upward-facing surface of the main body 23a of the other heat sink 223b, and the outer surfaces of each fin portion 23c. Each fin portion 23c comes into contact with the refrigerant L flowing through the second flow path 265. Other configurations of the holding portion 221 of this embodiment are similar to those of the holding portion 21 of the first embodiment described above.

[0089] Each of the pair of power modules 24 generates a current of a predetermined waveform from a current supplied by an external power supply (not shown), and supplies the generated current to the motor 91. Each power module 24 has a power semiconductor element 24c and a second connection terminal 26. The configurations of the power semiconductor element 24c and the second connection terminal 26 of this embodiment are similar to the configurations of the power semiconductor element 24c and the second connection terminal 26 of the first embodiment described above.

[0090] The second connection terminals 26 electrically connect the power semiconductor elements 24c arranged inside the power module 24 to the bus bar module 30. Although not shown, one power module 224a has six second connection terminals 226a. The six second connection terminals 226a include three second positive terminals 26a and three second negative terminals 26b. The other power module 224b has six second connection terminals 226b. The six second connection terminals 226b include three second positive terminals 26a and three second negative terminals 26b. Each second positive terminal 26a is electrically connected to a different pair of the power semiconductor elements 24c. Each second negative terminal 26b is electrically connected to a different pair of the power semiconductor elements 24c. As a result, current is supplied to each pair of the power semiconductor elements 24c from the bus bar module 230 via the second connection terminals 26. Other configurations of the power module 24 are similar to those of the power module 24 of the first embodiment described above.

[0091] One control board 225a that drives one power module 224a is disposed above (on the +D2 side of) one heat sink 223a. The other control board 225b that drives the other power module 224b is disposed below (on the -D2 side of) the other heat sink 223b. Connection pins 24d electrically connect one power module 224a to one control board 225a. This electrically connects each power semiconductor element 24c included in one power module 224a to one control board 225a. Furthermore, connection pins 24d electrically connect the other power module 224b to the other control board 225b. This electrically connects each power semiconductor element 24c included in the other power module 224b to the other control board 225b. Each control board 25 controls the power conversion of each power module 24 by providing a control pulse to each power semiconductor element 24c.

[0092] 3 , in this embodiment, the bus bar module 230 is disposed to the right (−D1 side) of the power module 24 and to the left (+D1 side) of the capacitor module 40. The bus bar module 230 has a first holding member 231 and a plurality of bus bars 233.

[0093] Although not shown, the first holding member 231 has a generally rectangular parallelepiped shape extending in the third direction D3. Two faces of the first holding member 231 face the first direction D1, and the other two faces of the first holding member 231 face the second direction D2. In this embodiment, the first holding member 231 is made of resin and has insulating properties. In this embodiment, the first holding member 231 is molded by insert molding using a plurality of bus bars 233 as insert members. As a result, the first holding member 231 holds each bus bar 233. A first through hole 231a is provided in the first holding member 231.

[0094] The first through holes 231a are holes that penetrate the first holding member 231 in the first direction D1. In the present embodiment, three first through holes 231a are provided in the first holding member 231. Although not shown in the drawings, the first through holes 231a are provided at intervals from one another along the third direction D3.

[0095] The plurality of bus bars 233 electrically connect the power module 24 and the capacitor module 240. Each bus bar 233 is a plate-shaped member. The plurality of bus bars 233 includes a first bus bar 234 and a second bus bar 235.

[0096] The first bus bar 234 has a first main body portion 234a and a first protrusion 234h. The first main body portion 234a is held by the first holding member 231. The first main body portion 234a is a plate-shaped member. Although not shown, the front end (+D3 side) of the first main body portion 234a is located forward of the second connection terminal 26 that is located furthest forward. The rear end (-D3 side) of the first main body portion 234a is located rearward of the second connection terminal 26 that is located furthest rearward. The first main body portion 234a has a first portion 234b, a second portion 234c, and a third portion 234d.

[0097] The first portion 234b and the second portion 234c each have a plate shape that protrudes in the first direction D1. The plate surfaces of the first portion 234b and the second portion 234c face the second direction D2. The left side (+D1 side) of the first portion 234b is fixed to each second negative electrode terminal 26b of one power module 224a by a bolt 82. The left side (+D1 side) of the second portion 234c is fixed to each second negative electrode terminal 26b of the other power module 224b by a bolt 82. As a result, the first bus bar 234 is electrically connected to the pair of power modules 24.

[0098] The third portion 234d has a plate shape extending in the second direction D2. The plate surface of the third portion 234d faces the first direction D1. The upper end of the third portion 234d is connected to the right end (-D1 side) of the first portion 234b. The lower end of the third portion 234d is connected to the right end of the second portion 234c. A first hole 234e and a second hole 234f are provided in the third portion 234d.

[0099] The first hole 234e and the second hole 234f each penetrate the third portion 234d in the first direction D1. When viewed from the third direction D3, the first hole 234e is provided above (toward +D2) the second hole 234f. In this embodiment, three first holes 234e are provided. The first holes 234e are provided at intervals from each other in the third direction D3. In this embodiment, three second holes 234f are provided. The second holes 234f are provided at intervals from each other in the third direction D3.

[0100] The first protrusion 234h has a plate shape and protrudes from the third portion 234d to the left (+D1 side). The plate surface of the first protrusion 234h faces the second direction D2. Although not shown, the first bus bar 234 has three first protrusions 234h. The first protrusions 234h are arranged at intervals from each other along the third direction D3. Other configurations of the first bus bar 234 are similar to those of the first bus bar 34 of the first embodiment described above.

[0101] The second bus bar 235 has a second main body portion 235a and a second protrusion 235h. The second main body portion 235a is held by the first holding member 231. The second main body portion 235a is a plate-shaped member. Although not shown, the front end (+D3 side) of the second main body portion 235a is located forward of the second connection terminal 26 arranged in the frontmost position. The rear end (-D3 side) of the second main body portion 235a is located rearward of the second connection terminal 26 arranged in the rearmost position. The second main body portion 235a has a fourth portion 235b, a fifth portion 235c, and a sixth portion 235d.

[0102] The fourth portion 235b and the fifth portion 235c each have a plate shape that protrudes in the first direction D1. The plate surfaces of the fourth portion 235b and the fifth portion 235c face the second direction D2. The left side (+D1 side) of the fourth portion 235b is fixed to the second positive terminals 26a of one power module 224a by bolts 82. The left side (+D1 side) of the fifth portion 235c is fixed to the second positive terminals 26a of the other power module 224b by bolts 82. As a result, the second bus bar 235 is electrically connected to the pair of power modules 24.

[0103] The sixth portion 235d has a plate shape extending in the second direction D2. The plate surface of the sixth portion 235d faces the first direction D1. The upper end of the sixth portion 235d is connected to the right end (-D1 side) of the fourth portion 235b. The lower end of the sixth portion 235d is connected to the right end of the fifth portion 235c. A third hole 235e and a fourth hole 235f are provided in the sixth portion 235d.

[0104] The third hole 235e and the fourth hole 235f each penetrate the sixth portion 235d in the first direction D1. When viewed from the third direction D3, the third hole 235e is provided above (toward +D2) the fourth hole 235f. In this embodiment, three third holes 235e are provided. The third holes 235e are spaced apart from each other in the third direction D3. In this embodiment, three fourth holes 235f are provided. The fourth holes 235f are spaced apart from each other in the third direction D3. When viewed from the first direction D1, a portion of the third hole 235e overlaps a portion of the first hole 234e. When viewed from the first direction D1, a portion of the fourth hole 235f overlaps a portion of the second hole 234f.

[0105] The second protrusion 235h has a plate shape and protrudes from the sixth portion 235d to the left (+D1 side). The plate surface of the second protrusion 235h faces the second direction D2. Although not shown, the second bus bar 235 has three second protrusions 235h. The second protrusions 235h are arranged at intervals along the third direction D3. Other configurations of the second bus bar 235 of this embodiment are similar to those of the second bus bar 35 of the first embodiment described above.

[0106] In this embodiment, the capacitor module 240 is disposed to the right (−D1 side) of the bus bar module 230. The capacitor module 240 includes a case 41 and a capacitor element 50. When viewed from the front (+D3 side), the capacitor module 240 of this embodiment is disposed in a state in which the capacitor module 40 of the first embodiment is rotated 90° counterclockwise around an axis extending in the third direction D3. Therefore, the first housing portion 42a is recessed to the right from the left side of the first case portion 42, i.e., the surface facing one side (+D1 side) in the first direction D1, i.e., the other side (−D1 side) in the first direction D1. Each protrusion 42c protrudes into the first flow path 62. The second housing portion 45a is recessed to the right from the surface facing the left side of the second case portion 45. The first flow path 62 is defined by the outer surface of the first case portion 42 and the inner surface of the second housing portion 45a. Other configurations of the case portion 41 are similar to those of the case portion 41 of the first embodiment described above.

[0107] Each capacitor body 51 is accommodated in a different first accommodation portion 42a. The first connection terminals 52 extend from the capacitor body 51 to the left, i.e., to one side (+D1 side) in the first direction D1. The two first connection terminals 52 include a first positive terminal 52a and a first negative terminal 52b.

[0108] The first positive electrode terminals 52a of each capacitor element 50 pass through different first through holes 231a in the first direction D1. The first positive electrode terminals 52a pass through the first hole 234e of the first bus bar 234 and the third hole 235e of the second bus bar 235 in the first direction D1, and are fixed to different second protrusions 235h of the second bus bar 235. This electrically connects each capacitor element 50 to the second bus bar 235. The first negative electrode terminals 52b of each capacitor element 50 pass through different first through holes 231a in the first direction D1. The first positive electrode terminals 52a pass through the second hole 234f of the first bus bar 234 and the fourth hole 235f of the second bus bar 235 in the first direction D1, and are fixed to different first protrusions 234h of the first bus bar 234. This electrically connects each capacitor element 50 to the first bus bar 234. Therefore, the bus bar 233 electrically connects the first connection terminal 52 to the second connection terminal 26. In this embodiment, the first connection terminal 52 and the bus bar 233 are fixed by welding. Other configurations of the capacitor module 240 of this embodiment are similar to those of the capacitor module 40 of the first embodiment described above.

[0109] The refrigerant flow path 260 of this embodiment is a flow path that supplies the refrigerant L to the first flow path 62 and the second flow path 265. The refrigerant flow path 260 has a first pipe line 61 (see FIG. 4), a first flow path 62, a second pipe line 63 (see FIG. 4), a third pipe line 64 (see FIG. 4), a second flow path 265, and a fourth pipe line 66 (see FIG. 4).

[0110] The second flow path 265 connects the third pipeline 64 and the fourth pipeline 66 shown in FIG. 4 . Although not shown, in the second flow path 265, the refrigerant L flows from the rear side (-D3 side) to the front side (+D3 side). As described above, each of the multiple fin portions 23c of the pair of heat sinks 23 comes into contact with the refrigerant L flowing through the second flow path 265. This increases the contact area between the refrigerant L flowing through the second flow path 265 and the pair of heat sinks 23. Other configurations of the refrigerant flow path 260 of this embodiment are similar to the configurations of the refrigerant flow path 60 of the first embodiment described above.

[0111] According to this embodiment, the capacitor element 50 includes a capacitor body 51 and a first connection terminal 52 extending from the capacitor body 51 to the left, i.e., toward one side (+D1 side) in the first direction. The case 41 is recessed from the left to the right, i.e., toward the other side (-D1 side) in the first direction D1, and includes a first housing portion 42a that houses the capacitor body 51 and a first flow path 62 through which the refrigerant L flows. This reduces the thermal resistance between the capacitor element 50 and the first flow path 62 compared to when the first flow path 62 is provided in a member different from the case 41. This increases the amount of heat transferred from the capacitor element 50 to the refrigerant L flowing through the first flow path 62. This prevents the temperature of the capacitor element 50 from becoming too high. This prevents the capacitor element 50 from deteriorating.

[0112] Furthermore, in this embodiment, the shape of the housing 11 can be simplified compared to a configuration in which the first flow path 62 is provided in the housing 11. This makes it possible to prevent an increase in the manufacturing cost of the housing 11.

[0113] According to this embodiment, the power conversion device 210 includes a holding unit 221 that holds the power module 24, and the holding unit 221 is provided with a second flow path 265 through which the coolant L flows. Therefore, compared to when the second flow path 265 is provided in a member different from the holding unit 221, the thermal resistance between the power module 24 and the second flow path 265 can be reduced. This makes it possible to increase the amount of heat transferred from the power module 24 to the coolant L flowing through the second flow path 265. Therefore, it is possible to prevent the temperature of the power module 24 from becoming too high.

[0114] Furthermore, in the present embodiment, since the second flow path 265 is provided in the holding portion 221, the shape and configuration of the housing 11 can be more suitably simplified compared to when the second flow path 265 is provided in the housing 11. This more suitably prevents the manufacturing cost of the housing 11 from increasing.

[0115] The present invention is not limited to the above-described embodiments, and other configurations and methods may be adopted within the scope of the technical concept of the present invention.

[0116] For example, the power module or the power semiconductor element may be in direct contact with the coolant without a heat sink, as long as insulation is ensured, which further increases the amount of heat transferred from the power semiconductor element to the coolant.

[0117] The application of the power conversion device of this embodiment is not limited to generating a current to be supplied to a motor that drives a vehicle, but may also generate a current to be supplied to a drive device such as a motor mounted on an electrical appliance, etc. Furthermore, the power conversion device may be an inverter that generates an AC current of a predetermined waveform from a DC current supplied from an external power supply, or may be a converter that generates a DC current from an AC current supplied from an external power supply.

[0118] Although the embodiments of the present invention have been described above, the configurations and combinations thereof in the embodiments are merely examples, and additions, omissions, substitutions, and other modifications of the configurations are possible without departing from the spirit of the present invention. Furthermore, the present invention is not limited to the embodiments.

[0119] The present technology can be configured as follows: (1) A power conversion device including: a capacitor module having a capacitor element and a case portion that houses the capacitor element; a power module having a power semiconductor element that performs power conversion; a control board that drives the power module; and a bus bar module having a bus bar, wherein the capacitor element has a capacitor body portion and a first connection terminal extending from the capacitor body portion to one side in a first direction; the power module has a second connection terminal; the bus bar electrically connects the first connection terminal and the second connection terminal; the case portion is recessed from the one side in the first direction to the other side in the first direction and has a first housing portion that houses the capacitor body portion and a first flow path through which a coolant flows. (2) The power conversion device according to (1), wherein the case portion has a first case portion in which the first housing portion is provided and a second case portion in which a second housing portion that houses the first case portion is provided, and the first flow path is defined by an outer surface of the first case portion and an inner surface of the second case portion. (3) The power conversion device according to (2), wherein the first case portion is made of metal. (4) The power conversion device according to (2) or (3), wherein the first case portion is provided with a plurality of protrusions that protrude into the first flow path. (5) The power conversion device according to any one of (2) to (4), wherein the second case portion is made of resin and is molded by insert molding using the first case portion as an insert member. (6) The power conversion device according to any one of (1) to (5), wherein the bus bar module includes a plurality of the bus bars and a first holding member made of resin that holds the plurality of bus bars, and the first holding member is molded by insert molding using the plurality of the bus bars as an insert member. (7) The power conversion device according to any one of (1) to (6), wherein the first connection terminal and the bus bar are fixed by welding. (8) The power conversion device according to any one of (1) to (7), wherein a holding portion that holds the power module is provided in the holding portion, and a second flow path through which the coolant flows. (9) A motor module comprising: the power conversion device according to any one of (1) to (8); and a motor driven by a current supplied from the power conversion device.

[0120] DESCRIPTION OF SYMBOLS 10,210...power conversion device, 21,221...holding portion, 22...holding case, 23...heat sink, 24...power module, 25...control board, 24c...power semiconductor element, 26...second connection terminal, 30,230...bus bar module, 31,231...first holding member, 33,233...bus bar, 40,240...capacitor module, 41...case portion, 42...first case portion, 42a...first accommodating portion, 42c...protruding portion, 45...second case portion, 45a...second accommodating portion, 50...capacitor element, 51...capacitor main body portion, 52...first connection terminal, 62...first flow path, 65,265...second flow path, 90...motor module, 91...motor, D1...first direction, L...refrigerant

Claims

1. A power conversion device comprising: a capacitor module having a capacitor element and a case portion that houses the capacitor element; a power module having a power semiconductor element that performs power conversion; a control board that drives the power module; and a busbar module having a busbar, wherein the capacitor element has a capacitor body portion and a first connection terminal extending from the capacitor body portion to one side in a first direction; the power module has a second connection terminal; the busbar electrically connects the first connection terminal and the second connection terminal; the case portion is recessed from the one side in the first direction to the other side in the first direction and has a first housing portion that houses the condenser body portion; and a first flow path through which a refrigerant flows.

2. A power conversion device as described in claim 1, wherein the case portion has a first case portion in which the first accommodating portion is provided, and a second case portion in which a second accommodating portion that accommodates the first case portion is provided, and the first flow path is formed by an outer surface of the first case portion and an inner surface of the second case portion.

3. The power conversion device according to claim 2, wherein the first case portion is made of metal.

4. The power conversion device according to claim 2, wherein the first case portion is provided with a plurality of protrusions protruding into the inside of the first flow path.

5. The power conversion device according to claim 2, wherein the second case portion is made of resin and is molded by insert molding using the first case portion as an insert member.

6. The power conversion device according to claim 1, wherein the busbar module has a plurality of the busbars and a first holding member made of resin that holds the plurality of the busbars, and the first holding member is molded by insert molding using the plurality of the busbars as insert members.

7. The power conversion device according to claim 1, wherein the first connection terminal and the bus bar are fixed by welding.

8. The power conversion device according to claim 1, further comprising a holding section for holding the power module, the holding section being provided with a second flow path through which the coolant flows.

9. A motor module comprising: a power conversion device according to any one of claims 1 to 8; and a motor driven by a current supplied from the power conversion device.