Power conversion device

Abstract

This power conversion device (10) is provided with: a power module (40) that performs power conversion; a holding unit (30) that holds the power module; a case (20) that accommodates the holding unit therein; and a refrigerant flow path (80) through which a refrigerant flows. The refrigerant flow path has a first flow path part (81) provided in the holding unit, and a second flow path part (23) provided in the case and connected to the first flow path part.

Description

Power Conversion Device

[0001] This application claims priority to Japanese Patent Application No. 2024-096764, filed on January 31, 2024, the contents of which are incorporated herein by reference.

[0002] As a power conversion device that supplies power to a motor, a power conversion device has been disclosed in which a refrigerant flow path is provided in a case that houses a power module unit having power semiconductors, and the power module unit is cooled by the refrigerant (for example, Patent Document 1).

[0003] Japanese Patent Publication No. 2013-031330

[0004] In the power conversion device described in Patent Document 1, when changing the arrangement of external piping provided outside the power conversion device, such as piping that supplies refrigerant to the refrigerant flow path and piping through which refrigerant discharged from the refrigerant flow path flows, it is necessary to change the configuration of the refrigerant flow path provided in the case to match the arrangement of the external piping. Therefore, depending on the arrangement of the external piping, it may be difficult to arrange the refrigerant flow path close to the power module, in which case there is a risk of increasing thermal resistance between the power module and the refrigerant flowing through the refrigerant flow path. Therefore, depending on the arrangement of the external piping, the amount of heat transferred from the power module to the refrigerant decreases, and there is a risk of the temperature of the power module becoming too high.

[0005] In view of the above circumstances, one aspect of the present invention aims to provide a power conversion device that can prevent the temperature of a power module from becoming too high, regardless of the arrangement of external piping.

[0006] One aspect of the power conversion device of the present invention includes a power module that performs power conversion, a holder that holds the power module, a case that houses the holder, and a coolant flow path through which a coolant flows. The coolant flow path has a first flow path portion provided in the holder, and a second flow path portion provided in the case and connected to the first flow path portion.

[0007] According to one aspect of the present invention, in a power conversion device, it is possible to prevent the temperature of a power module from becoming too high, regardless of the arrangement of external piping.

[0008] FIG. 1 is a perspective view showing a power conversion device of an embodiment. FIG. 2 is a first perspective view showing a portion of the power conversion device of the embodiment. FIG. 3 is a second perspective view showing a portion of the power conversion device of the embodiment. FIG. 4 is a cross-sectional view showing the power conversion device of the embodiment. FIG. 5 is a first perspective view showing a holding portion of the embodiment. FIG. 6 is a second perspective view showing the holding portion of the embodiment. FIG. 7 is a cross-sectional view showing the power conversion device of the embodiment, taken along VII-VII in FIG. 4. FIG. 8 is a perspective view showing a portion of a power conversion device of a modified embodiment.

[0009] 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.

[0010] 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. In the following description, the side toward which the arrow of the first direction D1 points (+D1 side) is referred to as the "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 "lower side."

[0011] In the following description, the second direction D2 is shown in each figure as appropriate. The second direction D2 is a direction perpendicular to the first direction D1. In this embodiment, the second direction D2 is the front-to-rear direction of the power conversion device. In the following description, the side toward which the arrow of the second direction D2 points (+D2 side) is referred to as the "front side." The side opposite to the side toward which the arrow of the second direction D2 points (-D2 side) is referred to as the "rear side."

[0012] 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. In this embodiment, the third direction D3 is the left-right direction of the power conversion device. In the following description, the side toward which the arrow of the third direction D3 points (the +D3 side) is referred to as the "right side." The side opposite the side toward which the arrow of the third direction D3 points (the -D3 side) is referred to as the "left side."

[0013] Note that the terms upper, lower, front, rear, right, and left are simply names used to explain the relative positional relationships of each part, and the actual positional relationships may be other than those indicated by these names.

[0014] FIG. 1 is a perspective view showing a power conversion device 10 according to the present embodiment. The power conversion device 10 is, for example, a power conversion device for supplying AC current to a drive device that rotates the axles of a vehicle and for recovering DC current from a power generation device that converts regenerative energy from the vehicle into electric power. The vehicle on which the power conversion device 10 is mounted is a vehicle powered by a drive device, such as a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), or an electric vehicle (EV). The power conversion device 10 converts DC current supplied from an external power source (not shown) into AC current and supplies it to the drive device. Furthermore, the power conversion device 10 converts AC current recovered from the power generation device into DC current and supplies it to the external power source. The power conversion device 10 supplies AC current to U-phase, V-phase, and W-phase coils of the drive device. The power conversion device 10 recovers AC current from the U-phase, V-phase, and W-phase coils of the power generation device. The power conversion device 10 includes a case 20, a holding unit 30, a power module 40, a capacitor module 50, and a coolant flow path 80. As shown in Fig. 2, the power conversion device 10 includes a bus bar unit 60. As shown in Fig. 3, the power conversion device 10 includes a control board 70.

[0015] As shown in FIG. 1 , the case 20 houses the components of the power conversion device 10, such as the holding unit 30, the power module 40, and the capacitor module 50. The case 20 is a substantially rectangular box. The case 20 is made of metal such as aluminum or copper. In this embodiment, the case 20 is made of aluminum. The case 20 has a first case 21 and a second case 25.

[0016] As shown in FIG. 4, the first case 21 is box-shaped and opens upward (toward +D1). The first case 21 is the lower portion (toward -D1) of the case 20. The first case 21 has a case support portion 22. As shown in FIG. 1, the case support portion 22 is a substantially rectangular parallelepiped that protrudes upward from the bottom of the first case 21. The case support portion 22 supports the holding portion 30 from below. The holding portion 30 is fixed to the case support portion 22. The case support portion 22 is provided with a second flow path portion 23. That is, the case 20 is provided with the second flow path portion 23.

[0017] 4, the second flow path portion 23 is provided inside the case support portion 22. The second flow path portion 23 is a flow path through which the refrigerant L flows. In the present embodiment, the second flow path portion 23 has a first portion 23a, a second portion 23b, and a third portion 23c.

[0018] The first portion 23a is provided on the left side (-D3 side) of the case support portion 22. The first portion 23a extends in the first direction D1. The upper end of the first portion 23a is open upward (+D1 side). The second portion 23b connects the first portion 23a and the third portion 23c. The second portion 23b extends in the third direction D3. The left end of the second portion 23b connects to the lower end of the first portion 23a.

[0019] The third portion 23c connects the second portion 23b and the discharge pipe 89b. The discharge pipe 89b is one of multiple external pipes 89 equipped on the vehicle. The refrigerant L flowing through the refrigerant flow path 80 is discharged to the discharge pipe 89b. The third portion 23c extends in the third direction D3. The upper end of the third portion 23c is connected to the right end (+D3 side) of the second portion 23b. The lower end of the third portion 23c opens downward (-D1 side). The lower end of the third portion 23c is connected to the discharge pipe 89b. Note that the configuration of the second flow path portion 23 is not limited to this embodiment and can be changed as appropriate to, for example, match the arrangement of the discharge pipe 89b.

[0020] 1, the second case 25 is box-shaped and opens downward (to the −D1 side). The second case 25 is fixed to the upper end of the first case 21.

[0021] The holding portion 30 holds the power module 40 and the capacitor module 50. As shown in FIG. 3, the holding portion 30 holds the control board 70. As shown in FIG. 1, the holding portion 30 is disposed inside the case 20. As described above, the holding portion 30 is fixed to the case support portion 22. The holding portion 30 is made of a metal such as aluminum or copper. In this embodiment, the holding portion 30 is made of aluminum. As shown in FIG. 5, the holding portion 30 has a holding main body portion 31, a control board accommodating portion 38, a first cylindrical portion 30f, a second cylindrical portion 39, and a fixing portion 30a. The holding portion 30 is provided with a first flow path portion 81.

[0022] The holding body 31 has a generally rectangular parallelepiped shape extending in the third direction D3. The holding body 31 has multiple outer surfaces. In this embodiment, the holding body 31 has six outer surfaces. Two outer surfaces of the holding body 31 face the first direction D1, and the other two outer surfaces of the holding body 31 face the second direction D2. The multiple outer surfaces of the holding body 31 include a holding outer surface 30d, a first outer surface 32, and a fourth outer surface 35. As shown in FIG. 6 , the multiple outer surfaces of the holding body 31 include a second outer surface 33. As a result, the holding portion 30 has the holding outer surface 30d, the first outer surface 32, the second outer surface 33, and the fourth outer surface 35. The holding outer surface 30d, the first outer surface 32, the second outer surface 33, and the fourth outer surface 35 are each different from one another.

[0023] 5, the first outer surface 32 is the outer surface facing the front (+D2 side) among the multiple outer surfaces of the holding body 31. That is, the first outer surface 32 faces the second direction D2. The first outer surface 32 is provided with a recess 32a. The recess 32a is a recess recessed from the first outer surface 32 into the inside of the holding portion 30. When viewed from the second direction D2, the recess 32a has a substantially rectangular shape with long sides extending in the third direction D3.

[0024] As shown in FIG. 6 , the second outer surface 33 is the outer surface facing the rear (−D2 side) of the multiple outer surfaces of the holding body 31. That is, the second outer surface 33 faces the second direction D2. A connecting pipe 33a is attached to the second outer surface 33. The connecting pipe 33a is generally cylindrical and protrudes rearward from the second outer surface 33. As shown in FIG. 7 , a connecting flow path 33b is provided inside the connecting pipe 33a. The connecting flow path 33b opens on both sides in the second direction D2. The connecting flow path 33b is a flow path through which the refrigerant L flows. Note that the connecting pipe 33a and the holding body 30 may be part of the same single member. As shown in FIG. 5 , the fourth outer surface 35 is the outer surface facing the left side (−D3 side) of the multiple outer surfaces of the holding body 31. That is, the fourth outer surface 35 faces the third direction D3.

[0025] In this embodiment, the holding body 31 has two holding outer surfaces 30d. That is, the holding body 30 has two holding outer surfaces 30d. The two holding outer surfaces 30d include a first holding outer surface 36 and a second holding outer surface 37. The first holding outer surface 36 is the outer surface facing upward (+D1 side) among the multiple outer surfaces of the holding body 31. As shown in FIG. 6, the second holding outer surface 37 is the outer surface facing downward (-D1 side) among the multiple outer surfaces of the holding body 31. As a result, each holding outer surface 30d faces the first direction D1. The first holding outer surface 36 and the second holding outer surface 37 face opposite sides of each other in the first direction D1. As described above, the first outer surface 32 faces the front side (+D2 side), and the second outer surface 33 faces the rear side (-D2 side). Therefore, the first outer surface 32, the second outer surface 33, and the outer retaining surface 30d face in different directions. Furthermore, the first outer retaining surface 36 and the second outer retaining surface 37 are connected to both the first outer surface 32 and the second outer surface 33. That is, the outer retaining surface 30d is connected to both the first outer surface 32 and the second outer surface 33.

[0026] As shown in FIG. 5 , the first holding outer surface 36 is provided with a power module cooling channel 83 and a first groove 36b. The power module cooling channel 83 is a recess recessed downward (toward the −D1 direction) from the first holding outer surface 36. When viewed from the first direction D1, the power module cooling channel 83 has a generally rectangular shape extending in the third direction D3. As shown in FIG. 4 , the power module cooling channel 83 is located above (toward the +D1 direction) the recess 32a. The power module cooling channel 83 is a channel through which the refrigerant L flows. As shown in FIG. 5 , the first groove 36b is a groove recessed downward from the first holding outer surface 36. When viewed from the first direction D1, the first groove 36b surrounds the power module cooling channel 83. The first groove 36b is provided around the edge of the power module cooling channel 83.

[0027] As shown in FIG. 6 , the second holding outer surface 37 is provided with a power module cooling channel 85 and a second groove 37b. The power module cooling channel 85 is a recess recessed upward (toward +D1) from the second holding outer surface 37. When viewed from the first direction D1, the power module cooling channel 85 has a generally rectangular shape extending in the third direction D3. As shown in FIG. 4 , the power module cooling channel 85 is located below (toward -D1) the recess 32a. The power module cooling channel 85 is a channel through which the refrigerant L flows. As shown in FIG. 6 , the second groove 37b is a groove recessed upward from the second holding outer surface 37. When viewed from the first direction D1, the second groove 37b surrounds the power module cooling channel 85. The second groove 37b is provided around the edge of the power module cooling channel 85.

[0028] As shown in FIG. 5 , the control board accommodating portion 38 is connected to the right end (+D3 side) of the holding body portion 31. As shown in FIG. 4 , the control board accommodating portion 38 has a bottom wall portion 38a, a peripheral wall portion 38b, and multiple mounting portions 38d. As shown in FIG. 5 , the bottom wall portion 38a is plate-shaped and extends in a direction perpendicular to the third direction D3. In this embodiment, the bottom wall portion 38a is substantially rectangular when viewed from the third direction D3. The shape of the bottom wall portion 38a when viewed from the third direction D3 may be other shapes, such as a circular shape. The bottom wall portion 38a is connected to the right end of the holding body portion 31. As shown in FIG. 4 , the surface of the outer surface of the bottom wall portion 38a facing right is the third outer surface 34. The third outer surface 34 faces right. That is, the third outer surface 34 faces the third direction D3. Therefore, the third outer surface 34 faces in a different direction from each of the first outer surface 32, the second outer surface 33, and the retaining outer surface 30d, which allows the third outer surface 34 to be positioned close to each of the first outer surface 32, the second outer surface 33, and the retaining outer surface 30d.

[0029] The peripheral wall portion 38b protrudes to the right (+D3 side) from the outer edge of the bottom wall portion 38a. As shown in FIG. 3 , the peripheral wall portion 38b has a generally rectangular ring shape when viewed from the third direction D3. The shape of the bottom wall portion 38a when viewed from the third direction D3 may be other shapes, such as a circular ring shape. The peripheral wall portion 38b surrounds the control board 70 from the outside in the first direction D1 and the outside in the second direction D2. As shown in FIG. 4 , each of the multiple mounting portions 38d has a columnar shape that protrudes to the right from the third outer surface 34. Although not shown, the multiple mounting portions 38d are arranged at intervals in each of the first direction D1 and the second direction D2.

[0030] As shown in FIG. 5, the first cylindrical portion 30f is disposed in the right side (+D3 side) and rear side (-D2 side) of the interior of the recess 32a. The first cylindrical portion 30f is cylindrical and extends in the first direction D1. In this embodiment, the first cylindrical portion 30f is part of the holding body 31. The first cylindrical portion 30f and the holding body 31 may be separate members. A control board cooling channel 84 is provided inside the first cylindrical portion 30f.

[0031] As shown in FIG. 4 , the control board cooling channel 84 extends in the first direction D1. The control board cooling channel 84 is a channel through which the coolant L flows. The control board cooling channel 84 opens on both the upper side (+D1 side) and the lower side (-D1 side). This connects the control board cooling channel 84 to both the power module cooling channel 83 and the power module cooling channel 85. The control board cooling channel 84 is located to the right (+D3 side) of the recess 32a. The control board cooling channel 84 is provided between the recess 32a and the control board 70.

[0032] 5, the second cylindrical portion 39 has a generally rectangular cylindrical shape extending in the second direction D2. The second cylindrical portion 39 is connected to a lower (-D1 side) portion of the fourth outer surface 35 of the holding body portion 31. In this embodiment, the second cylindrical portion 39 is a part of the holding body portion 31. The second cylindrical portion 39 and the holding body portion 31 may be separate members. The second cylindrical portion 39 is provided with a third flow path 87 and a plurality of protruding pipe portions 39c, 39d.

[0033] The third flow path 87 is provided inside the second cylindrical portion 39. The third flow path 87 extends in the second direction D2. The third flow path 87 is a flow path through which the refrigerant L flows.

[0034] Each of the multiple protruding pipes 39c, 39d protrudes downward (toward the -D1 direction) from the second cylindrical portion 39. In this embodiment, two protruding pipes 39c, 39d are provided in the second cylindrical portion 39. Three or more protruding pipes may be provided in the second cylindrical portion 39. The protruding pipes 39c, 39d are spaced apart in the second direction D2. As shown in FIG. 1, the protruding pipes 39c, 39d protrude toward the first case 21. As a result, the protruding pipes 39c, 39d protrude toward the case 20. As shown in FIG. 5, the interior of each of the protruding pipes 39c, 39d is connected to the third flow path 87. Each of the protruding pipes 39c, 39d is a flow path through which the refrigerant L flows. As shown in FIG. 4, in this embodiment, one of the protruding pipes 39c is inserted into the first portion 23a of the second flow path portion 23. As a result, at least one protruding pipe portion 39c is connected to the second flow path portion 23. The other protruding pipe portion 39d may be inserted into the first portion 23a. In this case, at least one protruding pipe portion 39d is also connected to the second flow path portion 23.

[0035] The fixing portion 30a shown in FIGS. 1 and 2 is fixed to the case support portion 22 of the first case 21. In this embodiment, the holding portion 30 has four fixing portions 30a. As shown in FIG. 1, the first fixing portion 30a is connected to the left end (-D3 side) of the first outer surface 32. The second fixing portion 30a is connected to the rear end (-D2 side) of the fourth outer surface 35. The third fixing portion 30a is connected to the right end (+D3 side) of the first outer surface 32. As shown in FIG. 2, the fourth fixing portion 30a is connected to the rear-facing outer surface of the peripheral wall portion 38b. Each fixing portion 30a has a through-hole (not shown) that penetrates the fixing portion 30a in the first direction D1. Each fixing member 96 shown in FIG. 1 fixes the fixing portion 30a to the case support portion 22. In this embodiment, each fixing member 96 is a male screw. When each fixing member 96 is inserted from above (+D1 side) into the through-hole of a different fixing portion 30a and tightened into a female screw hole (not shown) provided in the case support portion 22, each fixing portion 30a is fixed to the case support portion 22. In this way, the holding portion 30 is fixed to the case 20 by the fixing members 96.

[0036] The power module 40 generates a current with a predetermined waveform from currents supplied by an external power source and a power generation device (not shown), and supplies the current with the predetermined waveform to the drive device and the external power source, respectively. More specifically, the power module 40 is electrically connected to U-phase coils, V-phase coils, and W-phase coils (not shown) of the drive device and the power generation device, respectively, and supplies or recovers phase currents (U-phase current, V-phase current, and W-phase current). In this embodiment, the power module 40 converts DC current supplied from the external power source into AC current and supplies it to the drive device. In this embodiment, the power module 40 converts AC current recovered from the power generation device into DC current and supplies it to the external power source. In other words, the power module 40 performs power conversion. As shown in FIG. 4 , in this embodiment, the power conversion device 10 includes two power modules 40. The two power modules 40 include a first power module 41 and a second power module 45. In the following description, the first power module 41 may be referred to as one power module 40 , and the second power module 45 may be referred to as the other power module 40 .

[0037] As shown in FIG. 1 , the first power module 41 is disposed above (on the +D1 side of) the holding body 31. The first power module 41 is held by the first holding outer surface 36. That is, the first holding outer surface 36 holds one of the power modules 40. As shown in FIG. 2 , the second power module 45 is disposed below (on the −D1 side of) the holding body 31. The second power module 45 is held by the second holding outer surface 37. That is, the second holding outer surface 37 holds the other power module 40. As shown in FIG. 4 , the first power module 41 is disposed above the power module cooling channel 83. The power module cooling channel 83 is provided between the recess 32 a and the first power module 41. The second power module 45 is disposed below the power module cooling channel 85. The power module cooling channel 85 is provided between the recess 32 a and the second power module 45. As a result, the power module cooling flow paths 83 and 85 are provided between the recess 32 a and the power module 40 .

[0038] The first power module 41 is electrically connected to either a drive device or a power generation device (not shown). In this embodiment, the first power module 41 is electrically connected to the drive device and generates a current to be supplied to the drive device. The first power module 41 may also be electrically connected to a power generation device and recover a current generated by the power generation device. The first power module 41 includes a power board 42 and a power semiconductor module 43. That is, the power module 40 includes the power board 42 and the power semiconductor module 43. As shown in FIG. 7 , the power semiconductor module 43 includes a third connection terminal 44 and an output terminal 44d. That is, the first power module 41 includes the third connection terminal 44 and the output terminal 44d.

[0039] 1, the power board 42 has a plate shape extending in a direction perpendicular to the first direction D1. In this embodiment, the power board 42 is a printed circuit board on which a gate drive circuit (not shown) is formed. The power board 42 switches the power semiconductor elements of the power semiconductor module 43 based on control pulses output from the control board 70.

[0040] The power semiconductor module 43 has a power semiconductor element (not shown) and generates a current of a predetermined waveform from a current supplied from an external power supply. In this embodiment, the power semiconductor module 43 converts DC current into AC current, for example. In this embodiment, the power semiconductor element is, for example, an insulated gate bipolar transistor (IGBT) or a metal oxide semiconductor field effect transistor (MOSFET).

[0041] The third connection terminals 44 are plate-shaped and protrude forward (toward the +D2 side) beyond the power board 42. The plate surfaces of the third connection terminals 44 face the first direction D1. The third connection terminals 44 are electrically connected to the power semiconductor elements of the power semiconductor modules 43. The third connection terminals 44 are made of metal. In this embodiment, the first power module 41 has six third connection terminals 44. The six third connection terminals 44 include three third positive terminals 44a and three third negative terminals 44b.

[0042] The third positive terminals 44a are spaced apart from one another along the third direction D3. The third positive terminals 44a are electrically connected to different power semiconductor elements. The third negative terminals 44b are spaced apart from one another along the third direction D3. When viewed from the first direction D1, the third negative terminals 44b are positioned offset from the third positive terminals 44a in the third direction D3. The third negative terminals 44b are electrically connected to different power semiconductor elements.

[0043] As shown in FIG. 2 , the output terminal 44d is plate-shaped and protrudes rearward (toward the −D2 direction) beyond the power board 42. The plate surface of the output terminal 44d faces the first direction D1. The output terminal 44d is electrically connected to the power semiconductor element of the power semiconductor module 43. A current generated by the power semiconductor element flows through the output terminal 44d. The output terminal 44d is made of metal. The first power module 41 has three output terminals 44d. The output terminals 44d are arranged at intervals from each other along the third direction D3. One of a U-phase current, a V-phase current, and a W-phase current flows through each output terminal 44d.

[0044] As shown in FIG. 4 , the power semiconductor module 43 holds the power board 42. The power semiconductor module 43 is disposed below (on the −D1 side of) the power board 42. The downward-facing surface of the power semiconductor module 43 contacts the first outer retaining surface 36 in the first direction D1. The power semiconductor module 43 is fixed to the first outer retaining surface 36 with screws (not shown). This allows the first outer retaining surface 36 to hold one of the power modules 40. The power semiconductor module 43 blocks the power module cooling channel 83 from above (on the +D1 side). A seal member 97 is disposed inside the first groove 36b. In this embodiment, the seal member 97 is an O-ring. The seal member 97 contacts the inner surface of the first groove 36b and the downward-facing surface of the power semiconductor module 43. The seal member 97 seals the gap between the holder 30 and the power semiconductor module 43. The power semiconductor module 43 is provided with a plurality of protruding holding portions 43a and a plurality of protruding portions 43c.

[0045] The plurality of protruding holding portions 43a are columnar and protrude upward (toward the +D1 side) from the power semiconductor module 43. The power board 42 is fixed to the upper end of each protruding holding portion 43a. In this way, the power semiconductor module 43 holds the power board 42.

[0046] Each of the multiple protrusions 43c protrudes downward (toward the -D1 direction) from the power semiconductor module 43. Each protrusion 43c protrudes into the power module cooling flow path 83. This causes the coolant L flowing through the power module cooling flow path 83 to come into contact with the multiple protrusions 43c. Although not shown, in this embodiment, the protrusions 43c are arranged at intervals from one another along each of the second direction D2 and the third direction D3. Note that the power semiconductor module 43 does not necessarily have to have the protrusions 43c.

[0047] The second power module 45 is electrically connected to the other of the drive device and the power generation device (not shown). In this embodiment, the second power module 45 is electrically connected to the power generation device and recovers current generated by the power generation device. The second power module 45 may also be electrically connected to the drive device and generate current to be supplied to the drive device. The second power module 45 includes a power board 46 and a power semiconductor module 47. That is, the power module 40 includes the power board 46 and the power semiconductor module 47. As shown in FIG. 7 , the power semiconductor module 47 includes a third connection terminal 48 and an input terminal 48d. That is, the second power module 45 includes the third connection terminal 48 and the input terminal 48d. Note that in this embodiment, the shape and arrangement of each component of the second power module 45 are plane-symmetrical to the shape and arrangement of each component of the first power module 41, with a plane perpendicular to the first direction D1 as the plane of symmetry. In the following description, among the shapes and arrangements of the parts constituting the second power module 45, descriptions of the configurations and arrangements similar to those of the first power module described above may be omitted.

[0048] 2, the power board 46 has a plate shape that extends in a direction perpendicular to the first direction D1. In this embodiment, the power board 46 is a printed circuit board on which a gate drive circuit unit (not shown) is formed, and switches the power semiconductor elements of the power semiconductor module 47 based on control pulses output from the control board 70.

[0049] As shown in FIG. 7 , the third connection terminals 48 are plate-shaped and protrude forward (toward the +D2 side) beyond the power board 46. The third connection terminals 48 are electrically connected to the power semiconductor elements of the power semiconductor module 47. As shown in FIG. 1 , in this embodiment, the second power module 45 has six third connection terminals 48. The six third connection terminals 48 include three third positive terminals 48 a and three third negative terminals 48 b. Each third positive terminal 48 a is electrically connected to a different power semiconductor element. Each third negative terminal 48 b is electrically connected to a different power semiconductor element.

[0050] 2, the input terminal 48d is a plate-like terminal that protrudes rearward (toward the -D2 side) from the power board 46. The input terminal 48d is electrically connected to a power semiconductor element of the power semiconductor module 47. A current generated by the power generation device flows through the input terminal 48d. The second power module 45 has three input terminals 48d.

[0051] As shown in FIG. 4 , the power semiconductor module 47 holds the power board 46. The power semiconductor module 47 has power semiconductor elements (not shown) and generates a current with a predetermined waveform from the current generated by the power generation device. In this embodiment, the power semiconductor module 47 converts AC current to DC current, for example. The power semiconductor module 47 is disposed above the power board 46 (on the +D1 side). The upward-facing surface of the power semiconductor module 47 contacts the second outer retaining surface 37 in the first direction D1. The second outer retaining surface 37 holds the other power module 40. As described above, the first outer retaining surface 36 holds one power module 40. As a result, the outer retaining surface 30d holds the power module 40. The power semiconductor module 47 blocks the power module cooling channel 85 from the lower side (the -D1 side). A seal member 97 is disposed inside the second groove portion 37b. The seal member 97 seals the space between the holder 30 and the power semiconductor module 47. The power semiconductor module 47 is provided with a plurality of protruding holding portions 47a and a plurality of protruding portions 47c.

[0052] The plurality of protruding holding portions 47a are columnar and protrude downward (toward the -D1 direction) from the power semiconductor module 47. The power board 46 is fixed to the lower end of each protruding holding portion 47a. In this way, the power semiconductor module 47 holds the power board 46.

[0053] Each of the multiple protrusions 47c protrudes upward (towards the +D1 direction) from the power semiconductor module 47. Each protrusion 47c protrudes into the power module cooling flow path 85. As a result, the coolant L flowing through the power module cooling flow path 85 comes into contact with the multiple protrusions 47c.

[0054] According to this embodiment, the power conversion device 10 includes two power modules 40, and the holding unit 30 has two holding outer surfaces 30d. The two holding outer surfaces 30d include a first holding outer surface 36 that holds one power module 40 and a second holding outer surface 37 that holds the other power module 40, and the first holding outer surface 36 and the second holding outer surface 37 face opposite sides of each other in the first direction D1. Therefore, compared to when two power modules 40 are arranged on the same outer surface of the holding unit 30, it is easier to reduce the area of ​​the outer surface of the holding unit 30. This makes it possible to prevent the holding unit 30 from becoming larger in the direction perpendicular to the direction in which the outer surface of the holding unit 30 faces. This therefore makes it possible to prevent the power conversion device 10 from becoming larger.

[0055] The capacitor module 50 shown in Fig. 1 smoothes the current flowing between the external power supply and the power module 40. The capacitor module 50 has a positive electrode portion 51 and a negative electrode portion 54. As shown in Fig. 7, the capacitor module 50 has a positive electrode connection portion 52, a negative electrode connection portion 55, and a capacitor element 57.

[0056] The positive electrode portion 51 electrically connects an external power supply (not shown), the positive electrode connection portion 52, and the power module 40. The positive electrode portion 51 has a positive electrode main body portion 51a. The positive electrode main body portion 51a is plate-shaped and extends in a direction perpendicular to the second direction D2. As shown in FIG. 1 , the positive electrode portion 51 has a positive input terminal 51b and a positive electrode connection terminal 51c. The positive electrode connection terminal 51c includes a first positive electrode terminal 51d and a second positive electrode terminal 51e.

[0057] The positive input terminal 51b is a plate-like terminal that protrudes forward (toward +D2) from the right end (toward +D3) of the positive electrode main body 51a. A positive input bus bar 91a is joined to the positive input terminal 51b. The positive input bus bar 91a is electrically connected to an external power supply (not shown). This electrically connects the positive electrode 51 to the external power supply.

[0058] As shown in FIG. 7 , the first positive terminal 51d has a plate shape that protrudes forward (toward +D2) from the upper end of the positive electrode main body 51a. The plate surface of the first positive terminal 51d faces the first direction D1. As shown in FIG. 1 , in this embodiment, the positive electrode unit 51 has three first positive terminals 51d. The first positive terminals 51d are spaced apart from one another along the third direction D3. Each first positive terminal 51d is joined to a different third positive terminal 44a. In this embodiment, the first positive terminals 51d and the third positive terminal 44a are joined by welding. As described above, the third connection terminal 44 is electrically connected to the power semiconductor element included in the power semiconductor module 43. Therefore, the positive electrode unit 51 is electrically connected to the power semiconductor element included in the power semiconductor module 43. In other words, the positive electrode unit 51 is electrically connected to the first power module 41.

[0059] As shown in FIG. 7 , the second positive electrode terminal 51e has a plate shape that protrudes forward (toward +D2) from the lower end of the positive electrode main body 51a. The plate surface of the second positive electrode terminal 51e faces the first direction D1. As shown in FIG. 1 , in this embodiment, the positive electrode portion 51 has three second positive electrode terminals 51e. The second positive electrode terminals 51e are spaced apart from one another along the third direction D3. The second positive electrode terminals 51e are joined to different third positive electrode terminals 48a. In this embodiment, the second positive electrode terminals 51e and the third positive electrode terminals 48a are joined by welding. As described above, the third connection terminal 48 is electrically connected to the power semiconductor elements included in the power semiconductor module 47. Therefore, the positive electrode portion 51 is electrically connected to the power semiconductor elements included in the power semiconductor module 47. In other words, the positive electrode portion 51 is electrically connected to the second power module 45. As described above, the positive electrode portion 51 is electrically connected to the first power module 41. Therefore, the positive electrode portion 51 is electrically connected to the power module 40.

[0060] As shown in FIG. 7 , the positive electrode connection portion 52 has a generally L-shaped plate shape when viewed from the third direction D3. The positive electrode connection portion 52 has a first connection portion 52a and a second connection portion 52b. The first connection portion 52a is plate-shaped and extends in a direction perpendicular to the second direction D2. In the second direction D2, the first connection portion 52a is positioned forward (on the +D2 side) of the positive electrode main body portion 51a. The first connection portion 52a is joined to the positive electrode main body portion 51a. This electrically connects the positive electrode connection portion 52 to the positive electrode portion 51. The second connection portion 52b is plate-shaped and extends in a direction perpendicular to the first direction D1. The front end (on the +D2 side) of the second connection portion 52b is connected to the lower end of the first connection portion 52a. The second connection portion 52b is electrically connected to the positive electrode of the capacitor element 57. As a result, the capacitor element 57 is electrically connected to the positive electrode portion 51 via the positive electrode connecting portion 52. As described above, the positive electrode portion 51 is electrically connected to each of the first power module 41 and the second power module 45. As a result, the capacitor element 57 is electrically connected to each of the first power module 41 and the second power module 45. Therefore, the capacitor element 57 is electrically connected to the power module 40.

[0061] The negative electrode section 54 electrically connects an external power supply (not shown), a negative electrode connection section 55, and the power module 40. The negative electrode section 54 has a negative electrode main body section 54a. As shown in FIG. 1, the negative electrode section 54 has a negative input terminal 54b and a negative electrode connection terminal 54c. The negative electrode connection terminal 54c includes a first negative electrode terminal 54d and a second negative electrode terminal 54e.

[0062] 7, the negative electrode main body 54a has a plate shape that extends in a direction perpendicular to the second direction D2. The negative electrode main body 54a is disposed behind (on the −D2 side of) the positive electrode main body 51a.

[0063] The negative input terminal 54b shown in FIG. 1 is a plate-like terminal that protrudes forward (toward +D2) from the right end (toward +D3) of the negative electrode main body 54a. A negative input bus bar 91b is joined to the negative input terminal 54b. The negative input bus bar 91b is electrically connected to an external power supply (not shown). This electrically connects the negative electrode 54 to the external power supply.

[0064] As shown in FIG. 7 , the first negative electrode terminal 54d has a plate shape that protrudes forward (toward +D2) from the upper end of the negative electrode main body 54a. The plate surface of the first negative electrode terminal 54d faces the first direction D1. As shown in FIG. 1 , in this embodiment, the negative electrode portion 54 has three first negative electrode terminals 54d. The first negative electrode terminals 54d are spaced apart from one another along the third direction D3. The first negative electrode terminals 54d are joined to different third negative electrode terminals 44b. In this embodiment, the first negative electrode terminals 54d and the third negative electrode terminals 44b are joined by welding. As described above, the third connection terminal 44 is electrically connected to the power semiconductor elements included in the power semiconductor module 43. Therefore, the negative electrode portion 54 is electrically connected to the power semiconductor elements included in the power semiconductor module 43. As a result, the negative electrode portion 54 is electrically connected to the first power module 41.

[0065] As shown in FIG. 7 , the second negative electrode terminal 54e has a plate shape that protrudes forward (toward +D2) from the lower end of the negative electrode main body 54a. The plate surface of the second negative electrode terminal 54e faces the first direction D1. As shown in FIG. 1 , in this embodiment, the negative electrode portion 54 has three second negative electrode terminals 54e. The second negative electrode terminals 54e are spaced apart from one another along the third direction D3. The second negative electrode terminals 54e are joined to different third negative electrode terminals 48b. In this embodiment, the second negative electrode terminals 54e and the third negative electrode terminals 48b are joined by welding. As described above, the third connection terminal 48 is electrically connected to the power semiconductor elements included in the power semiconductor module 47. Therefore, the negative electrode portion 54 is electrically connected to the power semiconductor elements included in the power semiconductor module 47. As a result, the negative electrode portion 54 is electrically connected to the second power module 45. As described above, the negative electrode section 54 is electrically connected to the first power module 41. Therefore, the negative electrode section 54 is electrically connected to the power module 40.

[0066] As shown in FIG. 7 , the negative electrode connection portion 55 has a generally L-shaped plate shape when viewed from the third direction D3. The negative electrode connection portion 55 has a third connection portion 55a and a fourth connection portion 55b. The third connection portion 55a has a plate shape extending in a direction perpendicular to the second direction D2. The third connection portion 55a is disposed between the capacitor element 57 and the negative electrode main body portion 54a. The third connection portion 55a is joined to the negative electrode main body portion 54a. This electrically connects the negative electrode connection portion 55 to the negative electrode portion 54. The fourth connection portion 55b has a plate shape extending in a direction perpendicular to the first direction D1. The front end (+D2 side) of the fourth connection portion 55b is connected to the upper end of the third connection portion 55a. The fourth connection portion 55b is electrically connected to the negative electrode of the capacitor element 57. This electrically connects the capacitor element 57 to the negative electrode portion 54 via the negative electrode connection portion 55. As described above, the negative electrode portion 54 is electrically connected to each of the first power module 41 and the second power module 45. As a result, the capacitor element 57 is electrically connected to each of the first power module 41 and the second power module 45. Therefore, the capacitor element 57 is electrically connected to the power module 40.

[0067] As shown in FIG. 4 , in this embodiment, the capacitor module 50 includes a plurality of capacitor elements 57. In this embodiment, the capacitor module 50 includes four capacitor elements 57. The number of capacitor elements 57 included in the capacitor module 50 may be three or less, or may be five or more. The capacitor elements 57 are arranged side by side in the third direction D3. The capacitor elements 57 are arranged in the recess 32a. In this embodiment, the capacitor elements 57 are fixed to the inner surface of the recess 32a with an adhesive (not shown). This determines the position of each capacitor element 57 relative to the holder 30. As described above, the positive electrode of each capacitor element 57 is electrically connected to the power module 40 via the positive electrode connecting portion 52 and the positive electrode portion 51. The negative electrode of each capacitor element 57 is electrically connected to the power module 40 via the negative electrode connecting portion 55 and the negative electrode portion 54. The positive electrode portion 51 and the negative electrode portion 54 are each connected to an external power source (not shown). As a result, each capacitor element 57 smoothes the current flowing between the external power supply and the power module 40. As described above, the positive electrode portion 51 and the negative electrode portion 54 are each electrically connected to the power semiconductor elements included in the power semiconductor modules 43, 47. Therefore, each capacitor element 57 is electrically connected to the power semiconductor elements included in the power semiconductor modules 43, 47. As a result, each of the power semiconductor modules 43, 47 is electrically connected to the capacitor module 50.

[0068] According to this embodiment, the first outer surface 32 is provided with a recess 32a recessed into the holding portion 30, and the capacitor element 57 is disposed in the recess 32a. In a power conversion device 10 that generates a large current, the capacitance of the capacitor element 57 needs to be large in order to smooth the supplied current. Therefore, the capacitor element 57 used in a power conversion device 10 that generates a large current tends to be large, and moreover, multiple capacitor elements 57 are often used. In contrast, in this embodiment, the capacitor element 57 is disposed in the recess 32a recessed into the holding portion 30. Therefore, compared to a case in which the capacitor element 57 is disposed outside the holding portion 30, an increase in size of the power conversion device 10 can be more effectively prevented.

[0069] According to this embodiment, the holding outer surface 30d that holds the power module 40 is connected to the first outer surface 32 that holds the capacitor module 50. This facilitates shortening the distance between the power module 40 and the capacitor module 50, thereby facilitating miniaturization of the third connection terminals 44, 48 of the power module 40 and the positive and negative connection terminals 51c, 54c of the capacitor module 50. This facilitates simplifying the configuration for connecting the power module 40 and the capacitor module 50. This more effectively prevents an increase in the number of components in the power conversion device 10. In addition, because the power module 40 and the capacitor module 50 are held by the holding portion 30, the third connection terminals 44, 48 can be positioned close to the positive and negative connection terminals 51c, 54c. This facilitates joining the third connection terminals 44, 48 to the positive and negative connection terminals 51c, 54c. Therefore, an increase in the manufacturing cost and manufacturing steps of the power conversion device 10 can be more suitably suppressed.

[0070] As shown in FIG. 3 , the control board 70 is a printed circuit board extending in a direction perpendicular to the third direction D3. When viewed from the third direction D3, the control board 70 has a substantially rectangular shape. Although not shown, multiple electronic elements, such as integrated circuits (ICs) and resistors, are mounted on the control board 70. The control board 70 controls the operation of the power module 40. More specifically, the control board 70 controls the operation of the power semiconductor elements of the power semiconductor module 43 and the power semiconductor element of the power semiconductor module 47 via the power boards 42 and 46. The control board 70 controls the power conversion of the power module 40 by applying control pulses to the power semiconductor elements. As shown in FIG. 4 , the control board 70 is fixed to multiple mounting portions 38 d protruding from the third outer surface 34. This allows the control board 70 to be held on the third outer surface 34 of the holder 30. As shown in FIG. 3 , the control board 70 is housed within the control board housing 38.

[0071] According to this embodiment, the power conversion device 10 includes a control board 70 that controls the operation of the power module 40. The holding unit 30 has a third outer surface 34 that holds the control board 70. The third outer surface 34 faces in a different direction from the first outer surface 32, the second outer surface 33, and the holding outer surface 30d. This facilitates shortening the distance between the control board 70 and the power module 40, thereby simplifying the configuration of signal lines, such as cables, that connect the control board 70 and the power module 40. This prevents an increase in the number of components in the power conversion device 10 and simplifies the process of electrically connecting the control board 70 and the power module 40 via signal lines. This prevents an increase in the manufacturing cost and number of steps for the power conversion device 10.

[0072] According to this embodiment, the holding unit 30 has a control board accommodating portion 38 that accommodates the control board 70. Therefore, the control board accommodating portion 38 can prevent electromagnetic noise generated in the power module 40 from being transmitted to the control board 70. This can stabilize the operation of the control board 70. Therefore, the operation of the power conversion device 10 can be stabilized.

[0073] 2, the busbar unit 60 is disposed rearward (toward the −D2 direction) of the holding body 31. The busbar unit 60 faces the second outer surface 33 in the second direction D2. That is, the second outer surface 33 faces the busbar unit 60 in the second direction D2. The busbar unit 60 is electrically connected to the power module 40. The busbar unit 60 has a first busbar unit 61 and a second busbar unit 65.

[0074] The first busbar unit 61 has a plurality of busbars 62 and a busbar holding portion 63. That is, the busbar unit 60 has a plurality of busbars 62 and a busbar holding portion 63.

[0075] Each of the multiple bus bars 62 has a plate shape extending in the first direction D1. The bus bars 62 are arranged at intervals from one another along the third direction D3. The upper ends of the bus bars 62 are joined to different output terminals 44d. In the present embodiment, the bus bars 62 and the output terminals 44d are joined by welding. This electrically connects the first bus bar unit 61 to the first power module 41. A current generated by the first power module 41 flows through each bus bar 62. A different first output bus bar 92 shown in FIG. 1 is joined to the lower end of each bus bar 62. Although not shown, each first output bus bar 92 is electrically connected to a drive device (not shown). This electrically connects the first power module 41 to the drive device via each bus bar 62 and each first output bus bar 92.

[0076] As shown in FIG. 2 , the busbar holding portion 63 holds a plurality of busbars 62. The busbar holding portion 63 is made of resin. In this embodiment, the busbar holding portion 63 is molded by insert molding using each busbar 62 as an insert member. The busbar holding portion 63 insulates each busbar 62 from the holding portion 30. As shown in FIG. 7 , the busbar holding portion 63 contacts the second outer surface 33 of the holding portion 30. This brings the first busbar unit 61 into contact with the second outer surface 33.

[0077] 2, the second busbar unit 65 has a plurality of busbars 66 and a busbar holding portion 67. That is, the busbar unit 60 has a plurality of busbars 66 and a busbar holding portion 67.

[0078] Each of the multiple bus bars 66 has a plate shape extending in the first direction D1. The bus bars 66 are arranged at intervals from one another along the third direction D3. The lower ends of the bus bars 66 are joined to different input terminals 48d. In the present embodiment, the bus bars 66 are joined to the input terminals 48d by welding. This electrically connects the second bus bar unit 65 to the second power module 45. As described above, the first bus bar unit 61 is electrically connected to the first power module 41. This electrically connects the bus bar unit 60 to the power module 40. Different second output bus bars 93 shown in FIG. 1 are joined to the upper ends of the bus bars 66. Although not shown, each second output bus bar 93 is electrically connected to a power generation device (not shown). Current generated by the power generation device flows through each bus bar 66. As a result, the second power module 45 is electrically connected to the power generation device via each bus bar 66 and each second output bus bar 93 .

[0079] As shown in FIG. 2 , the busbar holding portion 67 holds a plurality of busbars 66. The busbar holding portion 67 is made of resin. In this embodiment, the busbar holding portion 67 is molded by insert molding using each busbar 66 as an insert member. The busbar holding portion 67 insulates each busbar 66 from the holding portion 30. As shown in FIG. 7 , the busbar holding portion 67 contacts the second outer surface 33 of the holding portion 30. As a result, the second busbar unit 65 contacts the second outer surface 33. As described above, the first busbar unit 61 contacts the second outer surface 33. As a result, the busbar unit 60 contacts the second outer surface 33.

[0080] In this embodiment, the first busbar unit 61 and the second busbar unit 65 have the same shape except for the shapes of the terminals connected to the drive unit and the power generator, respectively. That is, the plate materials of the three types of busbars connected to the U-phase, V-phase, and W-phase, respectively, are separated into busbar 62 connected to the drive unit and busbar 66 connected to the power generator, and the terminals for each are processed separately.

[0081] According to this embodiment, the holding unit 30 has a first outer surface 32 that holds the capacitor module 50, a second outer surface 33 that faces the bus bar unit 60, and a holding outer surface 30d that holds the power module 40, and the first outer surface 32, the second outer surface 33, and the holding outer surface 30d face in different directions. Therefore, compared to a case where at least two of the capacitor module 50, the bus bar unit 60, and the power module 40 are arranged on the same outer surface of the holding unit 30, it is easy to reduce the area of ​​the outer surface of the holding unit 30. This makes it possible to prevent the holding unit 30 from becoming larger in the direction perpendicular to the direction in which the outer surface of the holding unit 30 faces. This more effectively prevents the power conversion device 10 from becoming larger.

[0082] According to this embodiment, the holding outer surface 30d that holds the power module 40 is connected to the second outer surface 33 that holds the busbar unit 60. This makes it easy to shorten the distance between the power module 40 and the busbar unit 60, thereby enabling the output terminal 44d and the input terminal 48d of the power module 40 to be miniaturized. This facilitates simplifying the configuration for connecting the power module 40 and the busbar unit 60. This more effectively prevents an increase in the number of components in the power conversion device 10. In addition, because the power module 40 and the busbar unit 60 are held by the holding portion 30, the output terminal 44d and the input terminal 48d can be positioned close to the busbar unit 60. This makes it easy to join the output terminal 44d and the input terminal 48d to the busbar unit 60. This more effectively prevents an increase in the manufacturing cost and manufacturing man-hours of the power conversion device 10.

[0083] According to this embodiment, the first outer surface 32 and the second outer surface 33 each face a second direction D2 different from the first direction D1. In this embodiment, the third connection terminals 44, 48 of the power module 40 protrude forward (toward the +D2 side) from the power boards 42, 46, and the output terminal 44d and the input terminal 48d of the power module 40 protrude rearward (toward the -D2 side) from the power boards 42, 46. In this embodiment, because the first outer surface 32 facing forward holds the capacitor module 50, the third connection terminals 44, 48 of the power module 40 can be positioned close to the positive electrode connection terminal 51c and the negative electrode connection terminal 54c of the capacitor module 50. This further simplifies the configuration for connecting the power module 40 and the capacitor module 50. Furthermore, as described above, in this embodiment, the bus bar unit 60 is disposed to face the second outer surface 33 facing the rear, which makes it easier to more suitably reduce the size of the output terminal 44d and the input terminal 48d of the power module 40. This more suitably simplifies the configuration for connecting the power module 40 and the bus bar unit 60. This more suitably simplifies the configuration of the power conversion device 10. This more suitably prevents increases in the manufacturing costs and manufacturing steps of the power conversion device 10.

[0084] As described above, in this embodiment, the first busbar unit 61 and the second busbar unit 65 have the same shape except for the shapes of the terminals connected to the drive device and the power generation device, respectively. This allows the first busbar unit 61 and the second busbar unit 65 to be standardized, thereby reducing the manufacturing cost of the power conversion device 10.

[0085] The refrigerant flow path 80 shown in FIG. 4 is a flow path through which the refrigerant L flows. A pump and a cooler (not shown) are provided in the refrigerant flow path 80. The pump pressurizes 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 80 has a first flow path portion 81 and a second flow path portion 23. As described above, the first flow path portion 81 is provided in the holding portion 30. As described above, the second flow path portion 23 is provided in the case 20. More specifically, the second flow path portion 23 is provided in the case support portion 22 of the first case 21. The second flow path portion 23 is connected to the first flow path portion 81. As shown in FIG. 7, the first flow path portion 81 has a connection flow path 33b and a first flow path 82. As shown in FIG. 4 , the first flow path portion 81 has a power module cooling flow path 83, a control board cooling flow path 84, a power module cooling flow path 85, a second flow path 86, and a third flow path 87. As shown in FIG. 1 , the first flow path portion 81 has protruding pipe portions 39 c and 39 d. As shown in FIG. 4 , the second flow path portion 23 has a first portion 23 a, a second portion 23 b, and a third portion 23 c. In this embodiment, the refrigerant L flows through the connecting flow path 33 b, the first flow path 82, the power module cooling flow path 83, the control board cooling flow path 84, the power module cooling flow path 85, the second flow path 86, the third flow path 87, the protruding pipe portion 39 c, the first portion 23 a, the second portion 23 b, and the third portion 23 c in this order. The refrigerant L may flow in the following order: third portion 23c, second portion 23b, first portion 23a, protruding pipe portion 39c, third flow path 87, second flow path 86, power module cooling flow path 85, control board cooling flow path 84, power module cooling flow path 83, first flow path 82, and connecting flow path 33b.

[0086] As shown in FIG. 7 , the connection flow path 33b connects the supply pipe 89a and the first flow path 82. The supply pipe 89a is one of a plurality of external pipes 89 provided on the vehicle. The refrigerant L supplied to the refrigerant flow path 80 flows through the supply pipe 89a. The refrigerant L flows from the supply pipe 89a into the connection flow path 33b. The first flow path 82 connects the connection flow path 33b and the power module cooling flow path 83. The first flow path 82 is a hole that penetrates a portion of the holding portion 30 between the second outer surface 33 and the power module cooling flow path 83 in the second direction D2. In the first flow path 82, the refrigerant L flows from the rear side (−D2 side) to the front side (+D2 side).

[0087] As shown in FIG. 4 , the power module cooling flow path 83 connects the first flow path 82 and the control board cooling flow path 84. As described above, the power module cooling flow path 83 is provided between the recess 32a and the first power module 41. In the power module cooling flow path 83, the coolant L flows from the left side (-D3 side) to the right side (+D3 side). As described above, each protrusion 43c of the power semiconductor module 43 protrudes into the power module cooling flow path 83. Therefore, each protrusion 43c comes into contact with the coolant L flowing through the power module cooling flow path 83. This increases the contact area between the coolant L flowing through the power module cooling flow path 83 and the power semiconductor module 43.

[0088] The control board cooling channel 84 connects the power module cooling channel 83 and the power module cooling channel 85. As described above, the control board cooling channel 84 is provided between the recess 32a and the control board 70. In the control board cooling channel 84, the coolant L flows from the upper side (+D1 side) to the lower side (-D1 side).

[0089] The power module cooling flow path 85 connects the control board cooling flow path 84 and the second flow path 86. As described above, the power module cooling flow path 85 is provided between the recess 32a and the second power module 45. In the power module cooling flow path 85, the coolant L flows from the right side (the +D3 side) to the left side (the -D3 side). As described above, each protrusion 47c of the power semiconductor module 47 protrudes into the power module cooling flow path 85. Therefore, each protrusion 47c comes into contact with the coolant L flowing through the power module cooling flow path 85. This increases the contact area between the coolant L flowing through the power module cooling flow path 85 and the power semiconductor module 47.

[0090] The second flow path 86 connects the power module cooling flow path 85 and the third flow path 87. The second flow path 86 is a hole that penetrates in the third direction D3 through a portion of the holding part 30 between the fourth outer surface 35 and the power module cooling flow path 85. In the second flow path 86, the refrigerant L flows from the right side (+D3 side) to the left side (-D3 side).

[0091] As shown in FIG. 5 , the third flow path 87 connects the second flow path 86 and the protruding pipe portions 39c, 39d. In the third flow path 87, the refrigerant L flows in the second direction D2. In this embodiment, a cap member (not shown) is attached to the lower end of the other protruding pipe portion 39d. The cap member closes the lower end of the other protruding pipe portion 39d. This prevents the refrigerant L from leaking from the lower end of the other protruding pipe portion 39d. As shown in FIG. 4 , one protruding pipe portion 39c is inserted into the first portion 23a of the second flow path portion 23. The one protruding pipe portion 39c connects the third flow path 87 and the first portion 23a. This connects the second flow path portion 23 to the first flow path portion 81. In one protruding pipe portion 39c, the refrigerant L flows from the upper side (+D1 side) to the lower side (-D1 side). The refrigerant L flowing through one of the protruding pipe portions 39c flows into the second flow path portion 23. Note that, for example, in a case where the first portion 23a is disposed closer to the front (+D2 side) than in this embodiment in order to simplify the configuration of the second flow path portion 23, the second flow path portion 23 may be connected to the first flow path portion 81 by inserting the other of the protruding pipe portions 39d into the first portion 23a. In this case, by attaching a cap member (not shown) to the lower end of one of the protruding pipe portions 39c, it is possible to prevent the refrigerant L from leaking from the lower end of one of the protruding pipe portions 39c.

[0092] As described above, the second flow path portion 23 has the first portion 23a, the second portion 23b, and the third portion 23c. In this embodiment, the first portion 23a connects one of the protruding pipe portions 39c and the second portion 23b. The first portion 23a may also connect the other of the protruding pipe portions 39d and the second portion 23b. In the first portion 23a, the refrigerant L flows from the upper side (+D1 side) to the lower side (-D1 side). As described above, the second portion 23b connects the first portion 23a and the third portion 23c. In the second portion 23b, the refrigerant L flows from the left side (-D3 side) to the right side (+D3 side).

[0093] As described above, the third portion 23c connects the second portion 23b and the discharge pipe 89b. In the third portion 23c, the refrigerant L flows from the upper side (+D1 side) to the lower side (-D1 side). The refrigerant L that flows from the third portion 23c into the discharge pipe 89b is discharged to the outside of the power conversion device 10. The refrigerant L that flows into the discharge pipe 89b is cooled by the above-mentioned cooler and is pressure-fed to the supply pipe 89a by the above-mentioned pump.

[0094] According to this embodiment, the power conversion device 10 includes a power module 40 that performs power conversion, a holding unit 30 that holds the power module 40, a case 20 that houses the holding unit 30, and a refrigerant flow path 80 through which a refrigerant L flows. The refrigerant flow path 80 includes a first flow path portion 81 provided in the holding unit 30 and a second flow path portion 23 provided in the case 20 and connected to the first flow path portion 81. Unlike the configuration of the power conversion device 10 of this embodiment, in a configuration in which only the case 20 has the refrigerant flow path 80, the power module 40 is cooled by the refrigerant L flowing through the refrigerant flow path 80, and the refrigerant flow path 80 must be connected to external piping 89, such as a supply piping 89a and an exhaust piping 89b. Therefore, if the layout of the external piping 89 is changed due to a change in the design of the vehicle, the overall configuration of the refrigerant flow path 80 may need to be changed. Changing the overall configuration of the refrigerant flow path 80 requires changing the layout of each module and unit included in the power conversion device 10. This may increase the number of steps and costs required to manufacture the power conversion device 10. Furthermore, depending on the arrangement of the external piping 89, it may be difficult to arrange the refrigerant flow path 80 close to the power module 40. As a result, there is a risk that the thermal resistance between the power module 40 and the refrigerant L flowing through the refrigerant flow path 80 will increase. Therefore, depending on the arrangement of the external piping 89, the amount of heat transferred from the power module 40 to the refrigerant L flowing through the refrigerant flow path 80 will decrease, and the temperature of the power module 40 may become too high. In contrast, in this embodiment, the power module 40 is cooled by the refrigerant L flowing through the first flow path portion 81 provided in the holding portion 30, and the second flow path portion 23 provided in the case 20 is connected to the external piping 89. Therefore, even if the arrangement of the external piping 89 is changed due to a change in the design of the vehicle, the refrigerant flow path 80 can be connected to the external piping 89 by changing only the configuration of the second flow path portion 23 without changing the configuration of the first flow path portion 81. This allows the first flow path portion 81 to be disposed close to the power module 40 regardless of the arrangement of the external piping 89, thereby preventing a decrease in the amount of heat transferred from the power module 40 to the refrigerant L flowing through the first flow path portion 81. Therefore, regardless of the arrangement of the external piping 89, it is possible to prevent the temperature of the power module 40 from becoming too high.

[0095] Furthermore, in this embodiment, as described above, the refrigerant flow path 80 can be connected to the external piping 89 by changing only the configuration of the second flow path portion 23 provided in the case 20. Therefore, the degree of freedom in the configuration of the refrigerant flow path 80 can be increased while preventing the temperature of the power module 40 from becoming too high.

[0096] According to this embodiment, the first flow path portion 81 has power module cooling flow paths 83, 85 provided between the recess 32a and the power module 40. This makes it easy to shorten the distance between the power module cooling flow paths 83, 85 and the power module 40. More specifically, this embodiment makes it easy to shorten the distance between the power module cooling flow path 83 and the first power module 41 and the distance between the power module cooling flow path 85 and the second power module 45. This makes it possible to suitably increase the amount of heat transferred from the power module 40 to the refrigerant L flowing through the power module cooling flow paths 83, 85. Therefore, even in a power conversion device 10 including two power modules 40, the first power module 41 and the second power module 45, it is possible to more suitably prevent the temperature of each power module 40 from becoming too high.

[0097] According to this embodiment, the first flow path portion 81 has a control board cooling flow path 84 provided between the recess 32a and the control board 70. This makes it easy to shorten the distance between the control board cooling flow path 84 and the control board 70, thereby increasing the amount of heat transferred from the control board 70 to the coolant L flowing through the control board cooling flow path 84. This makes it possible to prevent the temperature of the control board 70 from becoming too high.

[0098] Furthermore, in this embodiment, as described above, the capacitor element 57 is disposed in the recess 32a. This facilitates shortening the distance between the capacitor element 57 and each of the power module cooling channels 83 and 85 and the control board cooling channel 84. That is, this facilitates shortening the distance between the capacitor element 57 and the first channel portion 81. This allows the amount of heat transferred from the capacitor element 57 to the refrigerant L flowing through the first channel portion 81 to be favorably increased. This effectively prevents the temperature of the capacitor element 57 from becoming too high. Furthermore, in this embodiment, the capacitor element 57 is surrounded by the inner surface of the recess 32a, which facilitates heat dissipation from the entire outer surface of the capacitor element 57 to the holding portion 30. This effectively prevents the temperature of the capacitor element 57 from becoming too high. Therefore, deterioration of the capacitor element 57 can be more favorably prevented, thereby improving the stability of the operation of the power conversion device 10.

[0099] According to the present embodiment, the power module 40 includes power boards 42, 46 connected to the capacitor module 50, and power semiconductor modules 43, 47 that hold the power boards 42, 46, and the power semiconductor modules 43, 47 have a plurality of protrusions 43c, 47c that protrude into the power module cooling channels 83, 85. Therefore, as described above, the contact area between the power semiconductor modules 43, 47 and the coolant L flowing through the power module cooling channels 83, 85 can be increased, and the amount of heat transferred from the power boards 42, 46 to the coolant L via the power semiconductor modules 43, 47 can be more suitably increased. Therefore, the power module 40 can be more suitably cooled to prevent the temperature from becoming too high.

[0100] According to the present embodiment, the busbar unit 60 is in contact with the second outer surface 33. This reduces the thermal resistance between the busbar unit 60 and the holding portion 30 compared to when the busbar unit 60 is disposed away from the holding portion 30. This reduces the thermal resistance between the busbar unit 60 and the first flow path portion 81 provided inside the holding portion 30, thereby increasing the amount of heat transferred from the busbar unit 60 to the coolant L flowing through the first flow path portion 81. This prevents the temperature of the busbar unit 60 from becoming too high, thereby preventing deterioration of the busbar unit 60. This further improves the operational stability of the power conversion device 10.

[0101] Furthermore, in this embodiment, heat generated in the power module 40 is transferred to each of the bus bars 62, 66 via the output terminal 44d and the input terminal 48d. This increases the amount of heat transferred from the power module 40 to the refrigerant L flowing through the first flow path portion 81 via the bus bar unit 60. This more effectively prevents the temperature of the power module 40 from increasing.

[0102] According to this embodiment, the first flow path portion 81 has a plurality of protruding pipe portions 39c, 39d protruding toward the case 20, and at least one of the protruding pipe portions 39c is connected to the second flow path portion 23. Therefore, the protruding pipe portion 39c to be connected to the second flow path portion 23 can be selected from the plurality of protruding pipe portions 39c, 39d. Therefore, compared to when the first flow path portion 81 has only one protruding pipe portion, it is easier to preferably simplify the configuration of the second flow path portion 23 that connects the first flow path portion 81 and the external piping 89. Therefore, an increase in the number of steps in manufacturing the case 20 can be preferably suppressed.

[0103] According to this embodiment, the holding portion 30 is fixed to the case 20 by the fixing member 96. Therefore, the connection between the protruding pipe portions 39c, 39d and the second flow path portion 23 can be stabilized, and leakage of the refrigerant L from between the protruding pipe portions 39c, 39d and the second flow path portion 23 can be suppressed.

[0104] <Modification> Fig. 8 is a perspective view showing a portion of a power conversion device 110 of this modification. The power conversion device 110 of this modification includes a case 20, a holding unit 30, a power module 40, a capacitor module 50, a refrigerant flow path 80, a control board 70, and a bus bar unit 160 shown in Fig. 8. The configurations of the case 20, the holding unit 30, the power module 40, the capacitor module 50, the refrigerant flow path 80, and the control board 70 of this modification are similar to the configurations of the case 20, the holding unit 30, the power module 40, the capacitor module 50, the refrigerant flow path 80, and the control board 70 of the above-described embodiment. In the following description, the same reference numerals are used to refer to components that are the same as those of the above-described embodiment, and description thereof will be omitted.

[0105] The busbar unit 160 is disposed rearward (toward the -D2 side) of the holding body portion 31. The busbar unit 160 faces the second outer surface 33 in the second direction D2. That is, the second outer surface 33 faces the busbar unit 160 in the second direction D2. The busbar unit 160 of this modified example includes a plurality of busbars 62, a plurality of busbars 66, and a busbar holding portion 163. The busbar unit 160 is electrically connected to the power module 40. A current generated by the power module 40 flows through the busbar unit 160. The configurations of the plurality of busbars 62 and the plurality of busbars 66 of this modified example are similar to the configurations of the plurality of busbars 62 and the plurality of busbars 66 of the above-described embodiment.

[0106] The busbar holding portion 163 is made of resin. The busbar holding portion 163 insulates the multiple busbars 62, 66 from the holding portion 30. In this embodiment, the busbar holding portion 163 is molded by insert molding, using the multiple busbars 62, 66 and the holding portion 30 as insert members. A portion of each busbar 62, 66 is embedded inside the busbar holding portion 163. This allows the busbar holding portion 163 to hold the multiple busbars 62, 66. The busbar holding portion 163 is also fixed to the second outer surface 33 of the holding portion 30. The busbar holding portion 163 comes into contact with the second outer surface 33. This brings the busbar unit 160 into contact with the second outer surface 33.

[0107] According to this modification, the busbar unit 160 includes a plurality of busbars 62, 66 and a busbar holding portion 163 that holds the plurality of busbars 62, 66. The busbar holding portion 163 is formed by insert molding, using the plurality of busbars 62, 66 and the holding portion 30 as insert members. Therefore, the busbars 62, 66 are fixed to the holding portion 30 via the busbar holding portion 163, thereby reducing the thermal resistance between the busbars 62, 66 and the first flow path portion 81 provided inside the holding portion 30. This increases the amount of heat transferred from the busbar unit 160 to the coolant L flowing through the first flow path portion 81. This prevents the temperature of the busbar unit 160 from becoming too high, thereby preventing deterioration of the busbar unit 160. This further improves the operational stability of the power conversion device 110.

[0108] 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.

[0109] For example, the case may house components other than those included in the above-described embodiments, such as a noise filter electrically connected between the external power supply and the capacitor element, a DC-DC converter that steps up and down DC current, and a charging component used in a plug-in hybrid vehicle, etc. Furthermore, the case may be configured integrally with a case that houses at least one of the drive device and the power generation device.

[0110] For example, two power modules may be electrically connected to the same drive device. In this case, one power module is electrically connected to one end of a coil in the drive device, and the other power module is electrically connected to the other end of the coil in the drive device. Furthermore, for example, a power module connected to a drive device may supply current to the drive device and recover regenerative current obtained from the drive device. While the terms "input" and "output" are used in the description of the present invention for simplicity, the present invention is not limited thereto, and the input and output may be reversed as long as it does not deviate from the spirit of the present invention.

[0111] The application of the power conversion device of this embodiment is not limited to generating currents to be supplied to a drive device that drives a vehicle and a power generation device that converts regenerative energy of the vehicle into electric power, but may also generate currents to be supplied to drive devices such as motors mounted on electrical appliances, etc. Furthermore, the power conversion device may be an inverter that generates AC current of a predetermined waveform from DC current supplied from an external power source, or may be a converter that generates DC current from AC current supplied from an external power source.

[0112] The above describes an embodiment of the present invention, but each configuration and combination thereof in the embodiment is merely an example, and additions, omissions, substitutions, and other modifications of the configuration are possible without departing from the spirit of the present invention. Furthermore, the present invention is not limited to the embodiment. Aspects of the present invention are also described in the following numbered clauses: (1) A power conversion device comprising: a power module that performs power conversion; a holding unit that holds the power module; a case that houses the holding unit; and a coolant flow path through which a coolant flows, the coolant flow path having a first flow path portion provided in the holding unit and a second flow path portion that is provided in the case and connected to the first flow path portion. (2) The power conversion device according to (1), further comprising: a capacitor module having a capacitor element electrically connected to the power module; the holding portion having a recess recessed inward from the first outer surface; and the capacitor element disposed in the recess. (4) The power conversion device described in (3), wherein the capacitor module has a positive electrode portion and a negative electrode portion electrically connected to the capacitor element, the positive electrode portion and the negative electrode portion have a positive electrode connection terminal and a negative electrode connection terminal extending toward the holding outer surface, the power module has a power semiconductor element and a third connection terminal electrically connected to the power semiconductor element, the first outer surface is connected to the holding outer surface, and the third connection terminal protrudes in a direction toward the first outer surface in the second direction and is electrically connected to the positive electrode connection terminal and the negative electrode connection terminal.(5) The power conversion device according to claim 3, wherein the first flow path portion has a power module cooling flow path provided between the recess and the power module. (6) The power conversion device according to (3), further comprising: a control board that controls operation of the power module, wherein the third outer surface is connected to the holding outer surface and holds the control board, and the first flow path portion has a control board cooling flow path provided between the recess and the control board. (7) The power conversion device according to (2), further comprising: a bus bar unit having a plurality of bus bars electrically connected to the power module and a resin bus bar holding portion that holds the plurality of bus bars, wherein the second outer surface is connected to the holding outer surface and holds the bus bar holding portion. (8) The power conversion device according to (4), wherein the capacitor module is fixed to the recess with an adhesive. (9) The power conversion device according to (1), wherein the holding portion has a fixing portion fixed to the case, and the first flow path portion has a pipe portion connected to the second flow path portion, and the fixing portion and the pipe portion face in the same direction.

[0113] REFERENCE SIGNS LIST 10, 110...power conversion device, 20...case, 23...second flow path section, 30...holding section, 40...power module, 80...refrigerant flow path, 81...first flow path section, L...refrigerant

Claims

1. A power conversion device comprising: a power module that performs power conversion; a holding section that holds the power module; a case that houses the holding section; and a refrigerant flow path through which a refrigerant flows, wherein the refrigerant flow path has a first flow path section that is provided in the holding section, and a second flow path section that is provided in the case and is connected to the first flow path section.

2. The power conversion device according to claim 1, wherein the holding section has a holding main body section having a generally rectangular parallelepiped shape and a plurality of outer surfaces, the plurality of outer surfaces including: two holding outer surfaces facing opposite each other in a first direction; a first outer surface and a second outer surface facing opposite each other in a second direction orthogonal to the first direction; and a third outer surface and a fourth outer surface facing opposite each other in a third direction orthogonal to both the first direction and the second direction; and the power modules include: a first power module held by a first holding outer surface that is one of the two holding outer surfaces; and a second power module held by a second holding outer surface that is the other of the two holding outer surfaces.

3. The power conversion device according to claim 2, further comprising a capacitor module having a capacitor element electrically connected to the power module, wherein the holding portion has a recess recessed inward from the first outer surface, and the capacitor element is disposed in the recess.

4. The power conversion device according to claim 3, wherein the capacitor module has a positive electrode portion and a negative electrode portion electrically connected to the capacitor element, the positive electrode portion and the negative electrode portion have a positive electrode connection terminal and a negative electrode connection terminal extending toward the holding outer surface, the power module has a power semiconductor element and a third connection terminal electrically connected to the power semiconductor element, the first outer surface is connected to the holding outer surface, and the third connection terminal protrudes in a direction toward the first outer surface in the second direction and is electrically connected to the positive electrode connection terminal and the negative electrode connection terminal.

5. The power conversion device according to claim 3, wherein the first flow path portion has a power module cooling flow path provided between the recess and the power module.

6. The power conversion device according to claim 3, further comprising a control board that controls the operation of the power module, wherein the third outer surface is connected to the holding outer surface and holds the control board, and the first flow path portion has a control board cooling flow path provided between the recess and the control board.

7. The power conversion device according to claim 2, further comprising a busbar unit having a plurality of busbars electrically connected to the power module and a resin busbar holding portion that holds the plurality of busbars, wherein the second outer surface is connected to the holding outer surface and holds the busbar holding portion.

8. The power conversion device according to claim 4, wherein the capacitor module is fixed in the recess with an adhesive.

9. The power conversion device according to claim 1, wherein the holding portion has a fixing portion that is fixed to the case, the first flow path portion has a pipe portion that is connected to the second flow path portion, and the fixing portion and the pipe portion face in the same direction.

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