Power conversion device

Abstract

To provide a power conversion device that achieves uniform cooling performance, miniaturization, and cost reduction.SOLUTION: A power conversion device includes: a flow path member that forms a coolant flow path through which a coolant flows; a first power module and a second power module that are disposed on one surface of the flow path member; and a third power module that is disposed on the other surface of the flow path member. The first power module is disposed on an upper stream side of the coolant flow path than the second power module. The third power module is opposed to the first power module and the second power module, and is disposed such that an opposed area to the first power module is larger than an opposed area to the second power module.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a power conversion device. [Background technology]

[0002] In a large current inverter, if the cooling flow path is continuous, the cooling performance of the power module on the outlet side decreases due to the rise in temperature of the cooling refrigerant. To solve this problem, for example, Patent Document 1 discloses a configuration of a power conversion device in which the opposing areas of the third power module and the first power module, and the third power module and the second power module are arranged to be equal, thereby ensuring cooling performance. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-11958 A Summary of the Invention [Problem to be solved by the invention]

[0004] In view of the technology described in Patent Document 1, it was necessary to further reduce the chip temperature difference between the power modules and achieve uniform cooling. [Means for solving the problem]

[0005] The power conversion device includes a flow path member that forms a refrigerant flow path through which a refrigerant flows, a first power module and a second power module that are arranged on one side of the flow path member, and a third power module that is arranged on the other side of the flow path member, wherein the first power module is arranged upstream of the refrigerant flow path relative to the second power module, and the third power module faces the first power module and the second power module and is arranged such that the facing area with the first power module is larger than the facing area with the second power module. Effect of the Invention

[0006] According to the present invention, it is possible to provide a power conversion device that realizes uniform cooling performance, miniaturization, and low cost. [Brief description of the drawings]

[0007] [Figure 1] 1 is an external perspective view of a power conversion device according to an embodiment of the present invention; [Diagram 2] Exploded view of the power module and flow path components in Figure 1 [Diagram 3] 1 is a cross-sectional view of a power module and a flow path member according to an embodiment of the present invention; [Figure 4] FIG. 1 is an explanatory diagram of a power module and a smoothing capacitor according to an embodiment of the present invention. [Diagram 5] FIG. 1 is an explanatory diagram of a PN bus bar according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The following description and drawings are examples for explaining the present invention, and appropriate omissions and simplifications have been made for clarity of explanation. The present invention can be implemented in various other forms. Unless otherwise specified, each component may be singular or plural.

[0009] In order to facilitate understanding of the invention, the position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings.

[0010] (One embodiment and overall configuration) (Figure 1) FIG. 1(a) is an overall view of an inverter device 1, FIG. 1(b) is a view of FIG. 1(a) with an upper cover 2 removed, and FIG. 1(c) is a view of a case 3 of FIG. 1(b) seen from the bottom side.

[0011] The inverter device 1 has an upper cover 2 made of aluminum and a case 3 made of aluminum. The inverter device 1 switches a DC current 9 input to the inverter device 1 with a power module 6, and outputs an AC current 10 to a motor (not shown). Inside the inverter device 1, components such as the power module 6, EMC 5, and MC board 4 are arranged. Each of these electrical components housed in the case 3 generates heat when a current passes through them. For this reason, the inverter device 1 is provided with a refrigerant flow path for cooling each component.

[0012] The inverter device 1 has an inlet 7 and an outlet 8. A refrigerant for cooling the inverter device 1 flows in from the inlet 7, circulates inside the inverter device 1, and is discharged from the outlet 8 to the outside of the inverter device 1.

[0013] (Figure 2) The inverter device 1 is composed of a plurality of power modules. For example, the first power module 11 has a GD substrate 12 and a shield plate 13, and the second power module 14 and the third power module 20 also have a GD substrate 12 and a shield plate 13.

[0014] The first power module 11 of the U phase, the second power module 14 of the W phase, and the third power module 20 of the V phase are provided with a power module base 18, which is a flow path member, in common with the power module. The first power module 11 and the second power module 14 are disposed on one side of the power module base 18, which is a flow path member, and the third power module 20 is disposed on the other side of the power module base 18.

[0015] The first power module 11, the second power module 14, and the third power module 20 are attached to a power module base 18 with an H-ring 17 sandwiched therebetween, thereby forming a refrigerant flow path for cooling each power module and keeping the refrigerant flow path airtight.

[0016] The PN bus bar 21 and the AC bus bar 16 are attached to the side of the power module base 18, and are welded to the live parts of the first power module 11, the second power module 14, and the third power module 20. The GD boards 12 of the first power module 11 and the second power module 14 are connected to the MC board 4 (FIG. 1), while the GD board 12 of the V-phase third power module 20 is connected to the MC board 4 via the GD-GDFPC 15 and the first power module 11.

[0017] (Figure 3) FIG. 3(a) is an overall view of the assembled power module and flow path member, FIG. 3(b) is a cross-sectional view taken along line AA in FIG. 3(a), FIG. 3(c) is a cross-sectional view taken along line BB in FIG. 3(a), and FIG. 3(d) is a cross-sectional view taken along line CC in FIG. 3(a).

[0018] The first power module 11 is disposed upstream of the second power module 14 in the refrigerant flow path 22. The refrigerant flows through the refrigerant flow path 22 from the upstream side on the left side of FIG. 3(b), cools the first power module 11, the third power module 20, and the second power module 14 in that order, and flows downstream on the right side of the drawing.

[0019] The PN bus bar 21 and the AC bus bar 16 are attached to a power module base 18, and are in contact with each other along the longitudinal direction of the refrigerant flow path 22. The PN bus bar 21 and the AC bus bar 16 are connected to the first power module 11, the second power module 14, and the third power module 20 by welding.

[0020] Each power module is assembled to the power module base 18 from above and below, with the third power module 20 facing the first power module 11 and the second power module 14. In order to increase the cross-sectional area on the upstream side of the third power module 20, the third power module 20 is disposed so that the area facing the first power module 11 is larger than the area facing the second power module 14. This makes it possible to change the flow speed of the refrigerant in the refrigerant flow path 22.

[0021] The first power module 11 and the third power module 20 can be overlapped on the flow path member to increase the flow path cross-sectional area, thereby decreasing the flow rate of the cold refrigerant on the upstream side. In addition, the second power module 14 can be overlapped on the flow path member to reduce the flow path cross-sectional area compared to the overlapped flow path cross-sectional area of ​​the first power module 11 and the third power module 20, thereby increasing the flow rate of the refrigerant on the downstream side, which is warmer than the upstream side. When the flow rate of the refrigerant supplied to the refrigerant flow path 22 is constant, the above-mentioned effects can be obtained, so that the cooling is uniformed and the chip temperatures of the upstream and downstream power modules can also be uniformed.

[0022] Furthermore, by arranging the third power module 20 downstream rather than vertically aligned with the first power module 11, a slide is not required in the mold, and the power module base 18 can be molded more easily than when the first power module 11 and the third power module 20 are aligned.

[0023] By arranging the PN bus bar 21 and the AC bus bar 16 along the refrigerant flow path 22 and in contact with the power module base 18, a large cooling area can be secured, and the PN bus bar 21 and the AC bus bar 16 can be indirectly cooled.

[0024] Although not shown, the AC bus bar 16 has a first bus bar electrically connected to the first power module 11, a second bus bar electrically connected to the second power module 14, and a third bus bar electrically connected to the third power module 16c. The first bus bar, the second bus bar, and the third bus bar are arranged so that their contact areas with the side surfaces of the flow path members are equal. This improves cooling performance and allows the thickness of the bus bars to be thin, contributing to cost reduction.

[0025] The PN bus bars 21 include a positive bus bar and a negative bus bar, and extend along the flow direction of the refrigerant in the flow path member, thereby improving cooling performance and allowing the thickness of the bus bars to be thin, contributing to cost reduction.

[0026] In addition, the cooling performance of each power module is improved by direct cooling by fins provided in the coolant flow path 22, so that the rise in chip temperature in each power module can be suppressed. This also allows the cross-sectional area of ​​the bus bar attached to the flow path member to be reduced, contributing to miniaturization. Moreover, by indirectly cooling the PN bus bar 21, the transfer of heat to surrounding components such as DC capacitors can be suppressed.

[0027] (Figure 4) Fig. 4(a) is an overall perspective view of the inverter device 1 with the cover removed, and Fig. 4(b) is a plan view of A in Fig. 4(a) seen from above. The inverter device 1 has DC input units 9a and 9b, to which a DC current 9 is input from the outside. The DC current 9 input to the inverter device 1 passes through electrical components within the inverter device 1 and is input to a smoothing capacitor 23.

[0028] Smoothing capacitors 23 have elements inside, from which connection terminals 19a protrude. When DC current 9 is input to each power module via smoothing capacitors 23 that smooth the voltage, bias in the current is suppressed by passing through connection terminals 19a provided at equal intervals. Connection terminals 19a are connected to the connection parts of PN bus bars 21, respectively, and are thereby connected to each power module.

[0029] (Figure 5) The PN bus bar 21 has a plurality of connection terminals 19b. The plurality of connection terminals 19b are respectively connected to a plurality of connection terminals 19a (FIG. 4) of the smoothing capacitor 23. The connection points of the connection terminals 19b are provided at three locations on the PN bus bar 21. The PN bus bar 21 also has a first connection portion 24 electrically connected to the first power module 11, a second connection portion 25 electrically connected to the second power module 14, and a third connection portion 26 electrically connected to the third power module 20.

[0030] In the PN bus bar 21, the connection terminals 19b are provided between the first connection portion 24 and the second connection portion 25 and on both outer sides of the first connection portion 24 and the second connection portion 25. The connection direction of the multiple connection terminals 19b is perpendicular to the connection direction of the first connection portion 24 and the second connection portion 25.

[0031] In this way, smoothing capacitor 23 can be welded from the top surface side of PN bus bar 21 during assembly, which contributes to space saving. Also, by providing connection terminals 19b arranged at equal intervals on PN bus bar 21 in correspondence with connection terminals 19a of smoothing capacitor 23, and by this, when DC current 9 is input to each power module via smoothing capacitor 23, the multiple connection terminals 19b arranged at equal intervals can suppress current bias and reduce inductance.

[0032] According to the embodiment of the present invention described above, the following advantageous effects are achieved.

[0033] (1) The power conversion device includes a flow path member that forms a refrigerant flow path through which a refrigerant flows, a first power module 11 and a second power module 14 that are disposed on one surface of the flow path member, and a third power module 20 that is disposed on the other surface of the flow path member. The first power module 11 is disposed upstream of the second power module 14 in the refrigerant flow path, and the third power module 20 faces the first power module 11 and the second power module 14 and is disposed such that the facing area with the first power module 11 is larger than the facing area with the second power module 14. In this way, it is possible to provide a power conversion device 1 that realizes uniform cooling performance, miniaturization, and cost reduction.

[0034] (2) The cross-sectional area of ​​the coolant flow path that cools the first power module 11 and the third power module 20 is larger than the cross-sectional area of ​​the coolant flow path that cools the second power module 14. This makes it possible to uniformize the temperature of the power module chips.

[0035] (3) In the refrigerant flow path, the third power module 20 is disposed downstream of the first power module 11. This makes it possible to easily mold the power module base 18.

[0036] (4) A bus bar is provided that is electrically connected to the first power module 11, the second power module 14, and the third power module 20. The bus bar is disposed on a side surface that connects one surface and the other surface of the flow path member. In this manner, the PN bus bar 21 and the AC bus bar 16 can be indirectly cooled.

[0037] (5) The bus bars include a first bus bar electrically connected to the first power module 11, a second bus bar electrically connected to the second power module 14, and a third bus bar electrically connected to the third power module 20. In the flow path member, the contact area between the first bus bar and the side surface of the flow path member, the contact area between the second bus bar and the side surface of the flow path member, and the contact area between the third bus bar and the side surface of the flow path member are equal. This improves cooling performance and allows the thickness of the bus bars to be reduced, contributing to cost reduction.

[0038] (6) The bus bar includes a positive bus bar and a negative bus bar, and the positive bus bar and the negative bus bar extend along the flow direction of the refrigerant in the flow path member. This improves cooling performance and enables the thickness of the bus bar to be thin, contributing to cost reduction.

[0039] (7) The positive bus bar and the negative bus bar include a first connection portion 24 electrically connected to the first power module 11 and a second connection portion 25 electrically connected to the second power module 14. The positive bus bar and the negative bus bar have a plurality of connection terminals 19 between the first connection portion 24 and the second connection portion 25 and on both outer sides of the first connection portion 24 and the second connection portion 25, the connection terminals 19 connecting to smoothing capacitors 23 that smooth out voltage. The connection direction of the plurality of connection terminals 19 is perpendicular to the connection direction of the first connection portion 24 and the second connection portion 25. This contributes to space saving.

[0040] The present invention is not limited to the above-described embodiment, and various modifications and other configurations can be combined without departing from the spirit of the present invention. Furthermore, the present invention is not limited to those having all of the configurations described in the above-described embodiment, and includes those in which some of the configurations are omitted. [Explanation of symbols]

[0041] 1. Inverter device 2 Upper cover 3 Cases 4 MC board 5. EMC 6 Power Module 7 Inlet 8. Outlets 9 DC current 9a DC input section (P) 9b DC input section (N) 10 AC current 11 First power module 12 GD board 13 Shield Plate 14 Second power module 15 GD-GDFPC 16 AC busbar 17 H-Ring 18 Power module base 19 Connection terminal 19a Smoothing capacitor connection terminal 19b PN bus bar 20 3rd power module 21 PN bus bar 22 Coolant flow path 22a Fins 23 Smoothing capacitor 24 First connection part 25 Second connection part 26 Third connection part

Claims

1. a flow path member that forms a refrigerant flow path through which a refrigerant flows; a first power module and a second power module disposed on one surface of the flow path member; a third power module disposed on the other surface of the flow path member, the first power module is disposed upstream of the second power module in the refrigerant flow path, The third power module faces the first power module and the second power module, and is disposed such that an opposing area between the third power module and the first power module is larger than an opposing area between the third power module and the second power module. Power conversion equipment.

2. The power conversion device according to claim 1, A cross-sectional area of ​​the refrigerant flow path that cools the first power module and the third power module is larger than a cross-sectional area of ​​the refrigerant flow path that cools the second power module. Power conversion equipment.

3. The power conversion device according to claim 1, In the refrigerant flow path, the third power module is disposed downstream of the first power module. Power conversion equipment.

4. The power conversion device according to claim 1, a bus bar electrically connected to the first power module, the second power module, and the third power module; The bus bar is disposed on a side surface connecting the one surface and the other surface of the flow path member. Power conversion equipment.

5. The power conversion device according to claim 4, the bus bars include a first bus bar electrically connected to the first power module, a second bus bar electrically connected to the second power module, and a third bus bar electrically connected to the third power module; In the flow path member, a contact area between the first bus bar and the side surface, a contact area between the second bus bar and the side surface, and a contact area between the third bus bar and the side surface are equal to each other. Power conversion equipment.

6. The power conversion device according to claim 4, The bus bars include a positive bus bar and a negative bus bar, The positive bus bar and the negative bus bar extend along a flow direction of the refrigerant in the flow path member. Power conversion equipment.

7. 7. The power conversion device according to claim 6, the positive bus bar and the negative bus bar include a first connection portion electrically connected to the first power module and a second connection portion electrically connected to the second power module, the positive bus bar and the negative bus bar have a plurality of connection terminals between the first connection portion and the second connection portion and on both outer sides of the first connection portion and the second connection portion, the connection terminals being connected to a smoothing capacitor that smoothes a voltage; A connecting direction of the plurality of connection terminals is perpendicular to a connecting direction of the first connection portion and the second connection portion. Power conversion equipment.

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