Power converter

Abstract

To provide a power conversion device with improved cooling performance. [Solution] The power converter 1 comprises a power module 10 having a first component 11 and a second component 12, which converts a DC voltage of a first voltage value to a DC voltage of a second voltage value, and a flow path housing 20 having a flow path 60 through which a cooling fluid flows. The flow path housing 20 has an opening facing one side in a first direction and a recess 21 provided adjacent to the flow path 60 along a second direction perpendicular to the first direction. The first component 11 is housed in the recess 21 via a heat transfer section 70 provided between the outer surface of the first component 11 and the inner wall portion 25 of the recess 21. The flow path 60 overlaps with the heat transfer section 70 in a second view and with the second component 12 in a first view.

Description

Technical Field

[0001] The present invention relates to a power conversion device that converts the voltage value of a DC voltage into a DC voltage of another voltage value.

Background Art

[0002] For example, in an electric vehicle that runs using electric energy, such as an automobile equipped with a motor as a driving power source (hybrid electric vehicle (HEV), plug-in hybrid electric vehicle (PHEV), battery electric vehicle (BEV), fuel cell electric vehicle (FCEV), etc.), a battery for driving the motor is mounted. When charging this battery or when using the power stored in the battery, a power conversion device that converts a DC voltage of a predetermined voltage value into a DC voltage of a desired voltage value is used. As a technology related to such a power conversion device, for example, there is one described in Patent Document 1 cited below.

[0003] Patent Document 1 describes a DC / DC converter. The DC / DC converter includes a switching MOS-FET, a rectifying diode, a voltage conversion transformer, and a smoothing choke coil. The MOS-FET and the diode are mounted on a substrate, and the transformer and the choke coil are formed on the substrate by patterning. The MOS-FET and the diode are connected to a cooling unit via a heat sink attached to the surface, and the transformer and the choke coil are provided so as to be able to radiate heat to the cooling unit via a heat radiating member provided on the side.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] As described above, the DC / DC converter described in Patent Document 1 cools the MOS-FET, diode, transformer, and choke coil by connecting them to a cooling section via a heat dissipation member. The heat generated by the components constituting such a DC / DC converter increases depending on the voltage conversion ratio and output current. Therefore, the DC / DC converter described in Patent Document 1 has room for improvement when higher cooling performance is required.

[0006] Therefore, there is a need for a power conversion device that can improve cooling performance. [Means for solving the problem]

[0007] The characteristic configuration of the power conversion device according to the present invention is a power module having a first component and a second component, which converts a DC voltage of a first voltage value to a DC voltage of a second voltage value, and a flow path housing having a flow path through which a cooling fluid flows, wherein the flow path housing has an opening facing one side in a first direction and a recess provided adjacent to the flow path along a second direction perpendicular to the first direction, the first component is housed in the recess via a heat transfer section provided between the outer surface of the first component and the inner wall of the recess, and the flow path overlaps with the heat transfer section in the second direction view and with the second component in the first direction view.

[0008] With this configuration, by providing a flow path in the wall portion of the recess, the first component located in the recess can be cooled via the heat transfer section, and the second component can also be cooled. Therefore, it is possible to improve the cooling performance. [Brief explanation of the drawing]

[0009] [Figure 1] This is a plan view of a power conversion device. [Figure 2] This is a cross-sectional view along line II-II in Figure 1. [Figure 3] This diagram shows the relationship between the recess, the flow path, and the coil. [Figure 4] This diagram shows the relationship between the flow path and the switching element. [Modes for carrying out the invention]

[0010] The power conversion device according to the present invention is configured to have high cooling performance. The power conversion device 1 of this embodiment will be described below. However, the power conversion device 1 is not limited to the following embodiment and can be modified in various ways without departing from the spirit of the invention.

[0011] In this embodiment, the power converter 1 is used to charge a high-voltage battery (for example, a battery with an output voltage of several hundred volts) that stores power used to drive the vehicle's motor, and to utilize the power stored in the high-voltage battery. Therefore, the power converter 1 is mounted on the vehicle.

[0012] High-voltage batteries are charged, for example, using commercial power. The use of the power stored in a high-voltage battery includes, for example, generating power equivalent to that of commercial power using that power, or generating power corresponding to different voltage values ​​using that power. Specifically, generating power corresponding to different voltage values ​​includes generating power to charge low-voltage batteries (for example, batteries with an output voltage of 12 volts).

[0013] Therefore, the power converter 1 charges a high-voltage battery mounted on the vehicle, which stores power used to drive the vehicle's motor using commercial power, generates power equivalent to commercial power using the power stored in the high-voltage battery, and generates power to charge a low-voltage battery, for example, using the power stored in the high-voltage battery.

[0014] Figure 1 shows a plan view of the power converter 1. Figure 2 shows a cross-sectional view taken along line II-II in Figure 1. As shown in Figure 1, the power converter 1 has a rectangular shape in plan view. In the following, the direction in which two of the four sides constituting this rectangular shape extend will be referred to as the X direction (an example of the "second direction"), and the direction perpendicular to the X direction will be referred to as the Y direction. Furthermore, the direction perpendicular to both the X and Y directions will be referred to as the Z direction (an example of the "first direction").

[0015] The power converter 1 comprises a power module 10 and a flow path housing 20. The flow path housing 20 is used as the housing for the power converter 1, and the power module 10 is housed in the flow path housing 20. The flow path housing 20 is constructed in a bottomed cylindrical shape, and when the power module 10 is housed inside, the opening is closed by a lid member (not shown).

[0016] The power module 10 converts the DC voltage of the first voltage value to the DC voltage of the second voltage value. When the power converter 1 charges the high-voltage battery, commercial power is supplied to the power converter 1. In this case, the power module 10 converts the AC power that makes up the commercial power into DC power, and the DC voltage that makes up the DC power converted in this way corresponds to the DC voltage of the first voltage value. The DC voltage of the second voltage value corresponds to a DC voltage of a second voltage value different from the first voltage value (for example, a second voltage value lower than the first voltage value).

[0017] Furthermore, when the power converter 1 utilizes the power charged in the high-voltage battery, the DC voltage output from the high-voltage battery corresponds to the DC voltage of the first voltage value. In this case, the DC voltage generated from the DC voltage from the high-voltage battery corresponds to a DC voltage of a second voltage value different from the first voltage value (for example, a second voltage value lower than the first voltage value).

[0018] The power supply module 10 has a plurality of substrates 15 and includes a first component 11 and a second component 12 mounted on one of the plurality of substrates 15. In the present embodiment, the first component 11 corresponds to a coil 30 including a core 31 and a wire 32 wound around the core 31, and the second component 12 corresponds to a switching element 40. In the present embodiment, the power supply module 10 is provided with a plurality of coils 30 and a plurality of switching elements 40.

[0019] The flow path housing 20 houses the power supply module 10. Each of the plurality of substrates 15 included in the power supply module 10 is accommodated in a state of being fastened and fixed by bolts 50 with the positions of bolt holes 51 provided in the flow path housing 20 and holes 16 provided in the substrates 15 aligned.

[0020] The flow path housing 20 has a flow path 60 through which a cooling fluid flows inside. The cooling fluid corresponds to, for example, a coolant mainly composed of ethylene glycol or the like, cooling water such as a long-life coolant, or an insulating oil such as a paraffin-based insulating oil. As shown in FIGS. 1 and 2, the flow path 60 is not exposed on the surface of the flow path housing 20 and is formed as a hollow hole inside. This hole communicates with an inlet (not shown) of the cooling fluid in the flow path housing 20, and the cooling fluid is introduced through the inlet. Further, it communicates with an outlet (not shown) of the cooling fluid in the flow path housing 20, and after flowing through the flow path 60, the cooling fluid is导出 from the outlet.

[0021] As shown in FIGS. 1 and 2, the flow path housing 20 has a recess 21. The recess 21 is open toward one side in the Z direction. One side in the Z direction is the side on which the substrate 15 is provided when the flow path housing 20 is viewed along the Z direction from the central portion in the Z direction. Therefore, the recess 21 is configured as a bottomed recess having a bottom 27 on the other side in the Z direction.

[0022] As shown in FIG. 2, the recess 21 is provided adjacent to the flow path 60 along the X direction. As described above, the recess 21 is not provided so as to be exposed on the surface of the flow path housing 20. Therefore, the flow path 60 is provided on the side surface portion of the recess 21. As shown in FIG. 1, the flow path 60 may be provided adjacent to at least one of the four side surface portions of the recess 21.

[0023] In the present embodiment, the recess 21 is configured to include a first recess 22 and a second recess 23. The first recess 22 is provided with the flow paths 60 on both sides along the X direction. Therefore, the first recess 22 is formed in a portion sandwiched between the two flow paths 60. The second recess 23 is provided on the opposite side of the first recess 22 with respect to one of the flow paths 60 on both sides of the first recess 22. That is, the second recess 23 is formed such that one of the flow paths 60 on both sides of the first recess 22 is sandwiched between the first recess 22 and the second recess 23 along the X direction. Therefore, when viewed from the side of the flow path 60 along the X direction, the flow path 60, the first recess 22, the flow path 60, and the second recess 23 are provided in this order.

[0024] The coil 30 is accommodated in the recess 21 through a heat transfer portion 70 provided between the outer surface of the coil 30 and the inner wall portion 25 of the recess 21. In the present embodiment, the coil 30 is configured to include a first coil portion 33 and a second coil portion 34. The first coil portion 33 and the second coil portion 34 are components that are provided as a set in terms of circuit configuration. Both the first coil portion 33 and the second coil portion 34 generate heat when energized, but the second coil portion 34 has a smaller amount of heat generation than the first coil portion 33. That is, the amount of heat generation of the first coil portion 33 is larger than the amount of heat generation of the second coil portion 34. For example, the first coil portion 33 can be configured using a wire 32 having an impedance smaller than the impedance of the wire 32 of the second coil portion 34. Also, the first coil portion 33 can be configured using a core 31 that is less likely to be magnetically saturated than the core 31 of the second coil portion 34. Of course, it may be configured such that a current having a current value smaller than the current value of the current flowing through the second coil portion 34 flows through the first coil portion 33.

[0025] In this embodiment, the first coil section 33 is housed in the first recess 22. The second coil section 34 is housed in the second recess 23. As described above, the first recess 22 is sandwiched between two flow channels 60 along the X direction, while the second recess 23 has a flow channel 60 on only one side in the X direction. Therefore, the cooling intensity (cooling performance) in the first recess 22 is greater (higher) than the cooling intensity (cooling performance) in the second recess 23. Consequently, of the first coil section 33 and the second coil section 34, the first coil section 33, which generates more heat, is housed in the first recess 22, which has a higher cooling intensity, and of the first coil section 33 and the second coil section 34, the second coil section 34, which generates less heat, is housed in the second recess 23, which has a lower cooling intensity.

[0026] In this embodiment, the first recess 22 has an internal dimension larger than the external dimension of the first coil portion 33, and the second recess 23 has an internal dimension larger than the external dimension of the second coil portion 34. Therefore, when the first coil portion 33 is provided in the first recess 22, a gap is provided between the inner wall portion 25 of the first recess 22 and the outer surface of the first coil portion 33. When the second coil portion 34 is provided in the second recess 23, a gap is provided between the inner wall portion 25 of the second recess 23 and the outer surface of the second coil portion 34. In order to improve heat transfer in this gap (to reduce thermal resistance), heat transfer sections 70 are provided between the inner wall portion 25 of the first recess 22 and the outer surface of the first coil portion 33, and between the inner wall portion 25 of the second recess 23 and the outer surface of the second coil portion 34. In this embodiment, the heat transfer section 70 is a gap filler made of a thermally conductive resin to fill the gaps described above. Of course, it is also possible to construct the heat transfer section 70 using a material other than the thermally conductive resin. Therefore, the first coil section 33 and the second coil section 34 are cooled by potting cooling, and the recess 21 is used as a potting tank in which a gap filler is provided.

[0027] Figure 3 is a view of the coil 30 housed in the recess 21, along the X direction (corresponding to the cross-sectional view III-III in Figure 1). As shown in Figure 3, the flow path 60 is provided such that at least a portion of it overlaps with the heat transfer section 70 in the X direction view. In this embodiment, one end 61 of the flow path 60 in the Z direction is provided on one side of the Z direction relative to the bottom 27 of the recess 21, and the other end 62 of the flow path 60 in the Z direction is provided on the other side of the Z direction relative to the bottom 27 of the recess 21. As a result, in the X direction view of the recess 21 and the flow path 60, the recess 21 and the flow path 60 overlap with each other over a range A along the Z direction. Therefore, it is possible to efficiently exchange heat between the heat of the coil 30 via the heat transfer section 70 and the cooling fluid flowing through the flow path 60.

[0028] Furthermore, in this embodiment, the end 71 on one side in the Z direction of the heat transfer section 70 is provided in such a state that it is located on one side in the Z direction, including the same position as the end 61 on one side in the Z direction of the flow path 60. The end 71 on one side in the Z direction of the heat transfer section 70 is the end 71 on the opposite side (opening side) of the bottom 27 of the recess 21 in the heat transfer section 70 when viewed in the X direction. The end 61 on one side in the Z direction of the flow path 60 is the end 61 on the opposite side (opening side) of the bottom 27 of the recess 21 in the flow path 60 when viewed in the X direction. Located on one side in the Z direction, including the same position, means that the end 71 and the end 61 are at the same position along the Z direction, or that the end 71 is located on the opposite side (opening side) of the bottom 27 than the end 61. Therefore, in an X-direction view, the end 71 of the recess 21 in the heat transfer section 70 on the opposite side of the bottom 27 (opening side) is located at the same position along the Z-direction as the end 61 of the recess 21 in the flow channel 60 on the opposite side of the bottom 27 (opening side), or the end 71 is located further away from the bottom 27 (opening side) than the end 61. In this embodiment, in an X-direction view, the end 71 of the recess 21 in the heat transfer section 70 on the opposite side of the bottom 27 (opening side) is located further away from the bottom 27 (opening side) than the end 61 of the recess 21 in the flow channel 60 on the opposite side of the bottom 27 (opening side).

[0029] Furthermore, when viewed along the X direction, the core 31 of the coil 30 overlaps with one end 71 in the Z direction of the heat transfer section 70 and one end 61 in the Z direction of the flow path 60. That is, as shown in Figure 3, when viewed along the X direction, the one end 71 in the Z direction of the heat transfer section 70 and one end 61 in the Z direction of the flow path 60 are contained within the core 31 of the coil 30. This makes it possible to transfer the heat from the coil 30 to the cooling fluid flowing through the flow path 60 via the heat transfer section 70 over the shortest distance.

[0030] Figure 4 is a view of the switching element 40 along the Z direction. As shown in Figure 4, the flow path 60 is provided such that it overlaps with the switching element 40 in at least part of the view in the Z direction. In this embodiment, the switching element 40 overlaps with the flow path 60 such that it is included in the range B along the X direction of the flow path 60 when viewed in the Z direction. This makes it possible to efficiently exchange heat between the switching element 40 and the cooling fluid flowing through the flow path 60.

[0031] In this embodiment, the coil 30 is provided such that the axis 31X of the core 31 is parallel to the X direction. As a result, at least a portion of the wire 32 comes into contact with the heat transfer section 70 while winding the core 31 once, making it possible to transfer heat from the wire 32 to the heat transfer section 70. Therefore, the wire 32 can efficiently exchange heat with the cooling fluid flowing through the flow path 60.

[0032] [Other Embodiments] Next, other embodiments of the power converter 1 will be described.

[0033] In the above embodiment, it was explained that the end 71 on one side in the Z direction of the heat transfer section 70 is provided in a state where it is located on one side in the Z direction, including the same position as the end 61 on one side in the Z direction of the flow path 60. However, the end 71 on one side in the Z direction of the heat transfer section 70 may be provided in a state where it is located on one side in the Z direction without including the same position as the end 61 on one side in the Z direction of the flow path 60, or the end 71 on one side in the Z direction of the heat transfer section 70 may be provided in a state where it is located on the other side in the Z direction than the end 61 on one side in the Z direction of the flow path 60.

[0034] In the above embodiment, the first component 11 was described as a coil 30 including a core 31 and a wire 32 wound around the core 31. However, the first component 11 may be a component other than the coil 30.

[0035] In the above embodiment, the coil 30 was described as being provided with the axis 31X of the core 31 parallel to the X direction. However, the coil 30 does not have to be provided with the axis 31X of the core 31 parallel to the X direction.

[0036] In the above embodiment, the coil 30 was described as having a core 31 that overlaps with one end 71 in the Z direction of the heat transfer section 70 and one end 61 in the Z direction of the flow path 60 when viewed along the X direction. However, the coil 30 does not have to have a core 31 that overlaps with at least one of the two ends 71 ​​in the Z direction of the heat transfer section 70 and one end 61 in the Z direction of the flow path 60 when viewed along the X direction.

[0037] In the above embodiment, the recess 21 was described as including a first recess 22 with flow channels 60 on both sides along the X direction, and a second recess 23 provided on the side opposite to the first recess 22 with respect to one of the flow channels 60. However, the recess 21 may be configured to include only one of the first recess 22 and the second recess 23.

[0038] In the above embodiment, the coil 30 was described as including a first coil portion 33 and a second coil portion 34 having a smaller heat generation capacity than the first coil portion 33. However, the coil 30 may be configured to include only one of the first coil portion 33 and the second coil portion 34.

[0039] In the above embodiment, the first coil portion 33 was described as being housed in the first recess 22 and the second coil portion 34 was described as being housed in the second recess 23. However, the first coil portion 33 may be housed in the second recess 23 and the second coil portion 34 may be housed in the first recess 22.

[0040] In the above embodiment, the heat transfer section 70 was described as a gap filler, the first coil section 33 and the second coil section 34 were cooled by potting cooling, and the recess 21 was used as a potting tank in which the gap filler was provided. However, the heat transfer section 70 can also be provided as a convex body projecting from the inner wall section 25 of the recess 21 toward the center of the recess 21. In this case, by press-fitting the first coil section 33 and the second coil section 34 into the recess 21 against the convex body, the heat of the first coil section 33 and the second coil section 34 can be cooled by the coolant flowing through the channel 60 via the convex body.

[0041] [Summary of the above embodiment] The following describes the overview of the power converter 1 described above.

[0042] (1) The power converter 1 comprises a power module 10 having a first component 11 and a second component 12, which converts a DC voltage of a first voltage value to a DC voltage of a second voltage value, and a flow path housing 20 having a flow path 60 through which a cooling fluid flows. The flow path housing 20 has an opening facing one side in the Z direction (first direction) and a recess 21 provided adjacent to the flow path 60 along the X direction (second direction) perpendicular to the Z direction. The first component 11 is housed in the recess 21 via a heat transfer section 70 provided between the outer surface of the first component 11 and the inner wall portion 25 of the recess 21. The flow path 60 is configured to overlap at least a portion with the heat transfer section 70 in the X direction view and at least a portion with the second component 12 in the Z direction view.

[0043] With this configuration, by providing a flow path 60 in the wall portion of the recess 21, the first component 11 provided in the recess 21 can be cooled via the heat transfer section 70, and the second component 12 can also be cooled. Therefore, it is possible to improve the cooling performance. In addition, by providing a flow path 60 in the wall portion of the recess 21, the wall thickness can be reduced, improving forging properties. Furthermore, by reducing the excess material of the flow path housing 20, the power conversion device 1 can be made lighter, and material costs can be reduced.

[0044] (2) In the power conversion device 1 described in (1), it is preferable that the end portion 71 on one side in the Z direction of the heat transfer section 70 is located on one side in the Z direction, including the same position as the end portion 61 on one side in the Z direction of the flow path 60.

[0045] With this configuration, the area in which the heat transfer section 70 and the flow path 60 overlap can be increased, so that heat can be efficiently exchanged with the flow path 60 via the heat transfer section 70.

[0046] (3) In the power conversion device 1 described in (1), the first component 11 is preferably a coil 30 including a core 31 and a wire 32 wound around the core 31, wherein the coil 30 is provided such that the axis 31X of the core 31 is parallel to the X direction.

[0047] With this configuration, at least a portion of the wire 32 can come into contact with the heat transfer section 70 while the wire 32 is winding around the core 31 once. Therefore, Joule heat in the wire 32 is easily transferred to the heat transfer section 70, making it possible to cool the wire 32. In particular, since the coil 30 can also be cooled from the side, the cooling efficiency is improved and the coil 30 can be made smaller.

[0048] In the power conversion device 1 described in (4)(3), it is preferable that the coil 30, when viewed along the X direction, has a core 31 that overlaps with one end 71 in the Z direction of the heat transfer section 70 and one end 61 in the Z direction of the flow path 60.

[0049] This configuration allows for efficient heat exchange between the core 31 and the coolant flowing through the channel 60.

[0050] In the power conversion device 1 described in (5)(3) or (4), the recess 21 includes a first recess 22 with flow paths 60 on both sides along the X direction, and a second recess 23 provided on the side opposite to the first recess 22 with respect to one of the flow paths 60 on both sides, and the coil 30 includes a first coil portion 33 and a second coil portion 34 having a smaller heat generation amount than the heat generation amount of the first coil portion 33, wherein the first coil portion 33 is housed in the first recess 22 and the second coil portion 34 is housed in the second recess 23.

[0051] This configuration allows for better cooling of the first coil section 33, which generates a large amount of heat. Furthermore, by configuring the flow path 60 only on one side of the second recess 23, where the second coil section 34, which generates less heat, is provided, along the second direction, the flow path housing 20 can be made smaller. [Industrial applicability]

[0052] The technology described herein can be used in a power conversion device that converts the voltage value of a DC voltage into a DC voltage of another voltage value. [Explanation of Symbols]

[0053] 1: Power converter, 10: Power module, 11: First component, 12: Second component, 20: Flow path housing, 21: Recess, 22: First recess, 23: Second recess, 25: Inner wall, 30: Coil, 31: Core, 31X: Axis, 32: Wire, 33: First coil section, 34: Second coil section, 60: Flow path, 70: Heat transfer section

Claims

1. A power supply module having a first component and a second component, which converts a DC voltage of a first voltage value to a DC voltage of a second voltage value, It comprises a flow path housing having a flow path through which a cooling fluid flows, The flow path housing has an opening facing one side in the first direction and a recess provided adjacent to the flow path along a second direction perpendicular to the first direction. The first component is housed in the recess via a heat transfer section provided between the outer surface of the first component and the inner wall of the recess. The power conversion device wherein the flow path overlaps with the heat transfer section in at least a portion of the second view and overlaps with the second component in at least a portion of the first view.

2. The power conversion device according to claim 1, wherein the end of the heat transfer section on one side in the first direction is provided in such a state that it is located on one side in the first direction, including the same position as the end of the flow path on one side in the first direction.

3. The first component is a coil including a core and a wire wound around the core, The power conversion device according to claim 1, wherein the coil is provided such that the axis of the core is parallel to the second direction.

4. The power conversion device according to claim 3, wherein, when viewed along the second direction, the core of the coil overlaps with one end in the first direction of the heat transfer section and one end in the first direction of the flow path.

5. The recess includes a first recess on both sides along the second direction, with the flow channels provided on both sides, and a second recess provided on the side opposite to the first recess with respect to one of the flow channels on both sides. The coil includes a first coil section and a second coil section having a smaller heat generation capacity than the first coil section. The power conversion device according to claim 3 or 4, wherein the first coil portion is housed in the first recess and the second coil portion is housed in the second recess.

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