Electric power conversion apparatus

Abstract

An electric power conversion apparatus (100A, 100B, 100C, 100D) comprises a cooler (10) and a component (50) disposed on the cooler. A refrigerant flow path (40) through which a refrigerant flows is provided in the cooler. A flow path surface area of the refrigerant flow path is reduced in a temperature range in which the temperature of the component is equal to or higher than a reference temperature.

Description

Power Conversion Device

[0001] The present disclosure relates to a power conversion device.

[0002] Japanese Patent Laid-Open No. 2015-130430 (Patent Document 1) describes a power module substrate with a heat sink, which is suppressed from deformation (warping) due to temperature changes.

[0003] JP 2015-130430 A

[0004] A cooler for cooling components such as power devices has a coolant flow path inside. A typical cooler is designed to minimize the flow area of ​​the coolant flow path to increase the flow rate of the coolant and promote heat transfer to the coolant. A design that reduces the flow area of ​​the coolant flow path increases pressure loss when the coolant flows through the coolant flow path. Suppressing deformation due to temperature changes, as in Patent Document 1, increases the pressure loss, which is inefficient when there is no need for strong cooling of the components, i.e., when the components are at low temperatures.

[0005] The present disclosure has been made in view of the above-described problems of the conventional technology. More specifically, the present disclosure provides a power conversion device capable of efficiently cooling components.

[0006] The power conversion device of the present disclosure includes a cooler and a component disposed on the cooler. The cooler includes a coolant flow path through which a coolant flows. The flow path area of ​​the coolant flow path is reduced in a temperature range where the temperature of the component is equal to or higher than a reference temperature.

[0007] The power conversion device of the present disclosure allows for efficient cooling of components.

[0008] 1. A perspective view of a power conversion device 100A. A cross-sectional view taken along line II-II in FIG. 1. A first explanatory diagram illustrating the operation of the power conversion device 100A. A second explanatory diagram illustrating the operation of the power conversion device 100A. A schematic diagram of a cooling system 200 using the power conversion device 100A. An explanatory diagram illustrating the operation of the power conversion device 100A according to a modified example. A cross-sectional view of a power conversion device 100B. A first explanatory diagram illustrating the operation of the power conversion device 100B according to a modified example. A second explanatory diagram illustrating the operation of the power conversion device 100B according to a modified example. A cross-sectional view of a power conversion device 100C. A bottom view of a top plate 30 in the power conversion device 100C. A first explanatory diagram illustrating the operation of the power conversion device 100C according to a modified example. A second explanatory diagram illustrating the operation of the power conversion device 100C according to a modified example. A bottom view of the top plate 30 in the power conversion device 100C according to a modified example. A cross-sectional view of a power conversion device 100D.

[0009] The details of the embodiments of the present disclosure will be described with reference to the drawings. In the following drawings, the same or corresponding parts are designated by the same reference numerals, and redundant descriptions will not be repeated.

[0010] First Embodiment A power conversion device according to a first embodiment will be described below. The power conversion device according to the first embodiment is designated as a power conversion device 100A.

[0011] (Configuration of Power Conversion Device 100A) The configuration of the power conversion device 100A will be described below.

[0012] Fig. 1 is a perspective view of a power conversion device 100A. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. As shown in Figs. 1 and 2, the power conversion device 100A includes a cooler 10 and a component 50.

[0013] The cooler 10 has a jacket 20 and a top plate 30. A refrigerant flow path 40 is provided inside the cooler 10. A refrigerant flows through the refrigerant flow path 40. The refrigerant is, for example, water.

[0014] The jacket 20 has a side wall 21 and a bottom wall 22. The bottom wall 22 is continuous with the lower end of the side wall 21. The space defined by the side wall 21 and the bottom wall 22 is an internal space 23 of the jacket 20. A refrigerant inlet 21a and a refrigerant outlet 21b are formed in the side wall 21. The refrigerant inlet 21a and the refrigerant outlet 21b connect the internal space 23 to the outside of the jacket 20.

[0015] The top plate 30 has a first surface 30a and a second surface 30b. The first surface 30a and the second surface 30b are end surfaces of the top plate 30 in the thickness direction. The second surface 30b is the surface opposite to the first surface 30a. The top plate 30 is attached to the jacket 20 so as to close the internal space 23. With the top plate 30 attached to the jacket 20, the first surface 30a faces the internal space 23. The refrigerant flow path 40 is defined by the internal space 23 and the top plate 30 (first surface 30a). The refrigerant flowing in from the refrigerant inlet 21a flows through the refrigerant flow path 40 and flows out from the refrigerant outlet 21b. Note that in FIG. 2 , the refrigerant flows in a direction perpendicular to the plane of the page.

[0016] The first surface 30a is provided with a plurality of fins 31. The fins 31 protrude from the first surface 30a toward the opposite side to the second surface 30b. In other words, the fins 31 are located inside the refrigerant flow path 40.

[0017] The component 50 is disposed on the cooler 10. More specifically, the component 50 is disposed on the second surface 30b. The component 50 is, for example, a power device having a power semiconductor element such as a metal oxide semiconductor field effect transistor (MOSFET), an insulated gate bipolar transistor (IGBT), or a diode. However, the component 50 is not limited to this. The component 50 may be, for example, a capacitor. The component 50 is in surface contact with the cooler 10 (second surface 30b), for example. The component 50 has, for example, a housing 51 and terminals 52 protruding from the housing 51. The housing 51 encapsulates the power semiconductor element, and the terminals 52 are electrically connected to the power semiconductor element.

[0018] FIG. 3 is a first explanatory diagram illustrating the operation of the power conversion device 100A. FIG. 4 is a second explanatory diagram illustrating the operation of the power conversion device 100A. FIG. 3 illustrates the state of the power conversion device 100A in a temperature range where the temperature of the component 50 is below a reference temperature, and FIG. 4 illustrates the state of the power conversion device 100A in a temperature range where the temperature of the component 50 is equal to or higher than the reference temperature. Note that this reference temperature is, for example, the lowest temperature in the operating temperature range of the component 50. As shown in FIGS. 3 and 4 , the top plate 30 warps toward the side away from the internal space 23 in a temperature range where the temperature of the component 50 is below the reference temperature, while it warps toward the internal space 23 in a temperature range where the temperature of the component 50 is equal to or higher than the reference temperature. As a result, the flow path area of ​​the coolant flow path 40 shrinks in a temperature range where the temperature of the component 50 is equal to or higher than the reference temperature.

[0019] The above-described change in the flow area of ​​the refrigerant flow path 40 is achieved by making the linear expansion coefficient of the top plate 30 greater than that of the component 50. To achieve a sufficient reduction in the flow area of ​​the refrigerant flow path 40, the difference between the linear expansion coefficients of the top plate 30 and the component 50 is, for example, 3 ppm / K or more and 10 ppm / K or less. This difference in linear expansion coefficient is preferably 7 ppm / K or more. For example, such a difference in linear expansion coefficient can be achieved when the top plate 30 is made of aluminum, an aluminum alloy, copper, or the like, and the component 50 is made of a DCB (Direct Copper Bonding) substrate (i.e., a substrate having a ceramic insulating layer and a copper wiring layer disposed on the ceramic insulating layer). The linear expansion coefficients of the top plate 30 and the component 50 are, for example, 17 ppm / K or more and 10 ppm / K or less, respectively.

[0020] Even when the difference between the linear expansion coefficient of the top plate 30 and the linear expansion coefficient of the component 50 is small, the flow path area of ​​the refrigerant flow path 40 can be sufficiently reduced by decreasing the rigidity of the top plate 30 (reducing the thickness of the top plate 30) or increasing the range of temperature change in the component 50. The change in the flow path area of ​​the refrigerant flow path 40 as described above may be achieved by making the linear expansion coefficient of the jacket 20 larger than the linear expansion coefficient of the top plate 30.

[0021] The jacket 20 is made of, for example, an aluminum alloy. The top plate 30 is made of, for example, aluminum, an aluminum alloy, copper, a copper alloy, or MMC (Metal Matrix Composites). The housing 51 is made of, for example, an epoxy resin containing silica filler. The terminals 52 are made of, for example, copper. The housing 51 may be formed by dropping silicone gel or the like into a mold.

[0022] 5 is a schematic diagram of a cooling system 200 using the power conversion device 100A. As shown in FIG. 5, the cooling system 200 includes the power conversion device 100A, a pump 110, and other component groups 120. The pump 110 circulates a refrigerant. As a result, the refrigerant flows into the refrigerant flow path 40 from the refrigerant inlet 21a and flows out from the refrigerant outlet 21b. The refrigerant that flows out from the refrigerant outlet 21b passes through the coolers of the other component groups 120 and returns to the pump 110. In this way, the cooling system 200 also cools the other component groups 120 that are connected in series to the power conversion device 100A.

[0023] (Effects of Power Conversion Device 100A) The effects of the power conversion device 100A will be described below.

[0024] When the temperature of the component 50 is low, there is little need for the cooler 10 to cool the component 50, whereas when the temperature of the component 50 is high, there is a high need for the cooler 10 to cool the component 50. In the power conversion device 100A, when the temperature of the component 50 is high, the flow path area of ​​the refrigerant flow path 40 is reduced, and the cooling performance of the cooler 10 is improved. On the other hand, when the temperature of the component 50 is low, the flow path area of ​​the refrigerant flow path 40 is expanded, and the cooling performance is reduced, but the pressure loss when the refrigerant flows through the refrigerant flow path 40 is reduced. Therefore, the power conversion device 100A enables efficient cooling of the component 50 in accordance with the temperature of the component 50.

[0025] (Modification) A modification of the power conversion device 100A will be described below.

[0026] FIG. 6 is an explanatory diagram illustrating the operation of a power conversion device 100A according to a modified example. As shown in FIG. 6, as the temperature of the component 50 increases, the tips of the fins 31 may come into contact with the jacket 20 (bottom wall 22). When the tips of the fins 31 come into contact with the jacket 20, the space between the tips of the fins 31 and the jacket 20 disappears, and the coolant no longer flows through this space. This makes it easier for the coolant to flow between adjacent fins 31. As a result, the cooling efficiency is further improved when the temperature of the component 50 increases. Note that when the temperature of the component 50 is low, the tips of the fins 31 move away from the jacket 20.

[0027] It is possible to arbitrarily set the temperature at which the tip of the fin 31 of the component 50 contacts the jacket 20. For example, by preliminarily warping the top plate 30 before attaching it to the jacket 20 and adjusting the degree of warping, it is possible to adjust the temperature of the component 50 when the tip of the fin 31 contacts the jacket 20.

[0028] Second Embodiment A power conversion device according to a second embodiment will be described. The power conversion device according to the second embodiment is designated as power conversion device 100B. Here, differences from power conversion device 100A will be mainly described, and overlapping descriptions will not be repeated.

[0029] (Configuration of Power Conversion Device 100B) The configuration of the power conversion device 100B will be described below.

[0030] Fig. 7 is a cross-sectional view of the power conversion device 100B. As shown in Fig. 7, the power conversion device 100B has a cooler 10 and a component 50. In the power conversion device 100B, the cooler 10 has a jacket 20 and a top plate 30, and a refrigerant flow path 40 is provided inside the cooler 10. In these respects, the configuration of the power conversion device 100B is common to the configuration of the power conversion device 100A.

[0031] In the power conversion device 100B, the top plate 30 is composed of multiple layers. In the example shown in FIG. 7 , the top plate 30 is composed of two layers (a first layer 32 and a second layer 33), and the fins 31 form part of the second layer 33. The second layer 33 is closer to the first surface 30a (closer to the refrigerant flow path 40) than the first layer 32. The layers constituting the top plate 30 have a larger linear expansion coefficient the closer they are to the first surface 30a (closer to the refrigerant flow path 40). In the example shown in FIG. 7 , the linear expansion coefficient of the second layer 33 is larger than that of the first layer 32. The first layer 32 is made of, for example, copper, a copper alloy, or MMC. The second layer 33 is made of, for example, aluminum or an aluminum alloy. In these respects, the configuration of the power conversion device 100B differs from the configuration of the power conversion device 100A.

[0032] (Effects of Power Conversion Device 100B) The effects of the power conversion device 100B will be described below.

[0033] In the power conversion device 100B, due to the difference in the linear expansion coefficient between the first layer 32 and the second layer 33, the flow path area of ​​the refrigerant flow path 40 decreases as the temperature of the component 50 increases, while the flow path area of ​​the refrigerant flow path 40 increases as the temperature of the component 50 decreases. As a result, as with the power conversion device 100A, efficient cooling of the component 50 is possible depending on the temperature of the component 50.

[0034] In the power conversion device 100B, the linear expansion coefficient of each of the multiple layers constituting the top plate 30 changes so that it becomes larger as it approaches the refrigerant flow path 40, making it possible to reduce the stress that occurs between adjacent layers and improve the structural reliability of the top plate 30.

[0035] (Modification) A modification of the power conversion device 100B will be described below.

[0036] Fig. 8 is a first explanatory diagram illustrating the operation of a power conversion device 100B according to a modified example. Fig. 9 is a second explanatory diagram illustrating the operation of a power conversion device 100B according to a modified example. As shown in Figs. 8 and 9 , the area of ​​the first layer 32 may be smaller than the area of ​​the second layer 33 in a plan view. That is, the outer periphery of the first layer 32 may be located more inward than the outer periphery of the second layer 33 in a plan view.

[0037] The outer peripheral edge of the second layer 33 in a plan view may be thicker than the portion of the second layer 33 located inside the outer peripheral edge. The outer peripheral edge of the second layer 33 is located on the upper end of the side wall 21. The first layer 32 is not disposed on the outer peripheral edge of the second layer 33. Note that the outer peripheral edge of the second layer 33 does not need to be thick all around. The outer peripheral edge of the second layer 33 may be thicker in parts.

[0038] The top plate 30 exhibits a large amount of warpage inside the outer peripheral edge of the second layer 33 due to the difference in linear expansion coefficient between the first layer 32 and the second layer 33. On the other hand, the outer peripheral edge of the second layer 33 has a larger thickness, so the amount of warpage is smaller. As a result, the coolant is less likely to leak out from between the jacket 20 and the top plate 30. In this way, with the above configuration, it is possible to achieve efficient cooling of the component 50 in accordance with the temperature of the component 50 while reducing the risk of coolant leakage.

[0039] Third Embodiment A power conversion device according to a third embodiment will be described. The power conversion device according to the third embodiment is designated as power conversion device 100C. Here, differences from power conversion device 100A will be mainly described, and overlapping descriptions will not be repeated.

[0040] (Configuration of Power Conversion Device 100C) The configuration of the power conversion device 100C will be described below.

[0041] Fig. 10 is a cross-sectional view of the power conversion device 100C. As shown in Fig. 10, the power conversion device 100C has a cooler 10 and a component 50. In the power conversion device 100C, the cooler 10 has a jacket 20 and a top plate 30, and a refrigerant flow path 40 is provided inside the cooler 10. In these respects, the configuration of the power conversion device 100C is common to the configuration of the power conversion device 100A.

[0042] FIG. 11 is a bottom view of the top plate 30 of the power conversion device 100C. Note that the fins 31 are not shown in FIG. 11. As shown in FIGS. 10 and 11, the first surface 30a has a first region 30aa and a second region 30ab. The first region 30aa is a region of the first surface 30a that overlaps with the component 50 in a plan view. The second region 30ab is a region of the first surface 30a that does not overlap with the component 50 in a plan view. In the example shown in FIG. 11, one component 50 is arranged in the center of the top plate 30 in a plan view, and the second region 30ab surrounds the periphery of the first region 30aa.

[0043] The fins 31 formed in the first region 30aa are referred to as fins 31a. The fins 31 formed in the second region 30ab are referred to as fins 31b. The fins 31b are longer than the fins 31a. In these respects, the configuration of the power conversion device 100C differs from the configuration of the power conversion device 100A.

[0044] (Effects of Power Conversion Device 100C) The effects of the power conversion device 100C will be described below.

[0045] Fig. 12 is a first explanatory diagram illustrating the operation of the power conversion device 100C according to the modified example. Fig. 13 is a second explanatory diagram illustrating the operation of the power conversion device 100C according to the modified example. As shown in Figs. 12 and 13 , when the temperature of the component 50 decreases, the top plate 30 warps toward the side opposite to the internal space 23, while when the temperature of the component 50 increases, the top plate warps toward the internal space 23.

[0046] As described above, because the fins 31b are longer than the fins 31a, when the temperature of the component 50 rises, the height positions of the tips of the fins 31a and 31b become closer to each other, narrowing the clearance between the tips of the fins 31a and 31b and the jacket 20 (bottom wall 22). As a result, the coolant is less likely to flow between the tips of the fins 31a and 31b and the jacket 20, and is more likely to flow between adjacent fins 31. In this way, the power conversion device 100C further improves the cooling efficiency when the temperature of the component 50 rises.

[0047] (Modification) A modification of the power conversion device 100C will be described below.

[0048] 14 is a bottom view of the top plate 30 of a power conversion device 100C according to a modified example. As shown in FIG. 14, when multiple components 50 are lined up in a row along the direction of the coolant flow, the first region 30aa may be disposed between two second regions 30ab in a direction perpendicular to the coolant flow. That is, the first region 30aa and the second region 30ab may be disposed in a striped pattern.

[0049] Fourth Embodiment A power conversion device according to a fourth embodiment will be described. The power conversion device according to the fourth embodiment is designated as power conversion device 100D. Here, differences from power conversion device 100A will be mainly described, and overlapping descriptions will not be repeated.

[0050] (Configuration of Power Converter 100D) The configuration of the power converter 100D will be described below.

[0051] Fig. 15 is a cross-sectional view of a power conversion device 100D. As shown in Fig. 15, the power conversion device 100D has a cooler 10 and a component 50. In the power conversion device 100D, the cooler 10 has a jacket 20 and a top plate 30, and a refrigerant flow path 40 is provided inside the cooler 10. In these respects, the configuration of the power conversion device 100D is common to the configuration of the power conversion device 100A.

[0052] The power conversion device 100D includes a plate member 60. The plate member 60 is disposed in the internal space 23 so as to face the top plate 30 with a gap therebetween. In the power conversion device 100D, the refrigerant flow path 40 is defined by the internal space 23, the top plate 30 (first surface 30a), and the plate member 60. The plate member 60 is composed of multiple layers. In the example shown in FIG. 15 , the plate member 60 is composed of a first layer 61 and a second layer 62. The layers constituting the plate member 60 have smaller linear expansion coefficients as they are closer to the refrigerant flow path 40. In the example shown in FIG. 15 , the linear expansion coefficient of the first layer 61 is smaller than that of the second layer 62. The first layer 61 is made of, for example, copper, a copper alloy, or MMC. The second layer 62 is made of, for example, aluminum or an aluminum alloy. In these respects, the configuration of the power conversion device 100D differs from the configuration of the power conversion device 100A.

[0053] (Effects of Power Conversion Device 100D) The effects of the power conversion device 100D will be described below.

[0054] As described above, the linear expansion coefficient of the first layer 61 is smaller than the linear expansion coefficient of the second layer 62. Therefore, in the power conversion device 100D, when the temperature of the component 50 rises, the plate member 60 warps toward the top plate 30, thereby reducing the flow path area of ​​the coolant flow path 40. On the other hand, when the temperature of the component 50 drops, the plate member 60 warps toward the opposite side from the top plate 30, thereby increasing the flow path area of ​​the coolant flow path 40. Therefore, according to the power conversion device 100D, as with the power conversion device 100A, the component 50 can be efficiently cooled in accordance with the temperature of the component 50.

[0055] (Modification) A modification of the power conversion device 100D will be described below.

[0056] Because the jacket 20 typically forms part of the inverter housing, it has high rigidity and is unlikely to warp. However, in the power conversion device 100D, the flow path area of ​​the refrigerant flow path 40 may be changed in accordance with the temperature of the component 50, for example, by reducing the thickness of the jacket 20 to lower the rigidity of the jacket 20. In this case, the power conversion device 100D may not include the plate member 60. In this case, the thickness of the jacket 20 is preferably 0.5 mm or more and 3.0 mm or more, from the viewpoint of ensuring the strength of the jacket 20 while allowing the flow path area of ​​the refrigerant flow path 40 to be changed.

[0057] (Appendix) Various aspects of the present disclosure are summarized as appendices.

[0058] <Supplementary Note 1> A power conversion device comprising: a cooler; and a component arranged on the cooler, wherein the cooler has a refrigerant flow path inside it through which a refrigerant flows, and a flow path area of ​​the refrigerant flow path is reduced in a temperature range in which the temperature of the component is equal to or higher than a reference temperature.

[0059] <Supplementary Note 2> The power conversion device according to Supplementary Note 1, wherein the cooler has a jacket and a top plate, the refrigerant flow path is defined by an internal space of the jacket and the top plate, the top plate has a first surface facing the internal space and a second surface opposite to the first surface, the component is disposed on the second surface, and a linear expansion coefficient of the top plate is greater than a linear expansion coefficient of the component.

[0060] <Supplementary Note 3> The power conversion device according to Supplementary Note 1, wherein the cooler has a jacket and a top plate, the refrigerant flow path is defined by an internal space of the jacket and the top plate, the top plate has a first surface facing the internal space and a second surface opposite to the first surface, the component is disposed on the second surface, and a linear expansion coefficient of the jacket is greater than a linear expansion coefficient of the top plate.

[0061] <Supplementary Note 4> The power conversion device according to Supplementary Note 1, wherein the cooler has a jacket and a top plate, the refrigerant flow path is defined by an internal space of the jacket and the top plate, the top plate has a first surface facing the internal space and a second surface opposite to the first surface, the components are arranged on the second surface, and the top plate is made up of a plurality of layers stacked along a thickness direction of the top plate.

[0062] <Supplementary Note 5> The power conversion device according to Supplementary Note 4, wherein the plurality of layers include a first layer and a second layer located closer to the first surface than the first layer, and a linear expansion coefficient of the second layer is greater than a linear expansion coefficient of the first layer.

[0063] <Supplementary Note 6> The power conversion device according to Supplementary Note 4, wherein the plurality of layers include a first layer and a second layer located closer to the first surface than the first layer, wherein an area of ​​the first layer is smaller than an area of ​​the second layer in a planar view, and wherein a thickness of the second layer is at least partially thicker at an outer peripheral edge portion than an inside of the outer peripheral edge portion.

[0064] <Supplementary Note 7> The power conversion device according to Supplementary Note 1, wherein the cooler has a jacket and a top plate, the refrigerant flow path is defined by an internal space of the jacket and the top plate, the top plate has a first surface facing the internal space and a second surface opposite the first surface, the component is disposed on the second surface, a plurality of fins are formed on the first surface, the first surface has a first region overlapping with the component in a plan view and a second region not overlapping with the component in a plan view, the plurality of fins include a first fin formed in the first region and a second fin formed in the second region, and the second fin is longer than the first fin.

[0065] <Supplementary Note 8> The power conversion device according to Supplementary Note 1, wherein the cooler has a jacket and a top plate, the refrigerant flow path is defined by an internal space of the jacket and the top plate, the top plate has a first surface facing the internal space and a second surface opposite the first surface, the component is disposed on the second surface, a plurality of fins are formed on the first surface, and at least some of the plurality of fins come into contact with the jacket when a flow path area of ​​the refrigerant flow path is reduced.

[0066] <Supplementary Note 9> The power conversion device according to Supplementary Note 1, wherein the cooler has a jacket, a top plate, and a plate member, the plate member is disposed in an internal space of the jacket, the refrigerant flow path is defined by the internal space, the top plate, and the plate member, the top plate has a first surface facing the internal space and a second surface opposite to the first surface, the component is disposed on the second surface, and a plurality of fins are formed on the second surface, and an area of ​​the refrigerant flow path is changed by warping deformation of the plate member due to a temperature change of the component.

[0067] <Supplementary Note 10> The power conversion device according to Supplementary Note 1, wherein the cooler has a jacket and a top plate, the refrigerant flow path is defined by an internal space of the jacket and the top plate, the top plate has a first surface facing the internal space and a second surface opposite to the first surface, the component is disposed on the second surface, and an area of ​​the refrigerant flow path is changed by warpage deformation of the jacket accompanying a temperature change of the component.

[0068] <Supplementary Note 11> The power conversion device according to any one of Supplementary Note 1 to Supplementary Note 10, wherein the reference temperature is a minimum temperature in an operating temperature range of the component.

[0069] <Supplementary Note 12> The power conversion device according to any one of Supplementary Note 1 to Supplementary Note 11, wherein the component is a power device.

[0070] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of this application is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0071] 100A, 100B, 100C, 100D Power conversion device, 10 Cooler, 20 Jacket, 21 Side wall, 21a Coolant inlet, 21b Coolant outlet, 22 Bottom wall, 23 Internal space, 30 Top plate, 30a First surface, 30aa First region, 30ab Second region, 30b Second surface, 31, 31a, 31b Fins, 32 First layer, 33 Second layer, 40 Coolant flow path, 50 Component, 51 Housing, 52 Terminal, 60 Plate member, 61 First layer, 62 Second layer, 110 Pump, 120 Component group, 200 Cooling system.

Claims

1. A power conversion device comprising: a cooler; and a component arranged on the cooler, wherein the cooler has a refrigerant flow path inside it through which a refrigerant flows, and the flow path area of ​​the refrigerant flow path is reduced in a temperature range where the temperature of the component is equal to or higher than a reference temperature.

2. The power conversion device of claim 1, wherein the cooler has a jacket and a top plate, the refrigerant flow path is defined by the internal space of the jacket and the top plate, the top plate has a first surface facing the internal space and a second surface opposite the first surface, the component is arranged on the second surface, and the linear expansion coefficient of the top plate is greater than the linear expansion coefficient of the component.

3. The power conversion device of claim 1, wherein the cooler has a jacket and a top plate, the refrigerant flow path is defined by the internal space of the jacket and the top plate, the top plate has a first surface facing the internal space and a second surface opposite the first surface, the component is arranged on the second surface, and the linear expansion coefficient of the jacket is greater than the linear expansion coefficient of the top plate.

4. The power conversion device of claim 1, wherein the cooler has a jacket and a top plate, the refrigerant flow path is defined by the internal space of the jacket and the top plate, the top plate has a first surface facing the internal space and a second surface opposite the first surface, the component is arranged on the second surface, and the top plate is composed of a plurality of layers stacked along the thickness direction of the top plate.

5. The power conversion device according to claim 4, wherein the plurality of layers include a first layer and a second layer located closer to the first surface than the first layer, and the linear expansion coefficient of the second layer is greater than the linear expansion coefficient of the first layer.

6. A power conversion device as described in claim 4, wherein the plurality of layers include a first layer and a second layer located closer to the first surface than the first layer, and in a planar view, an area of ​​the first layer is smaller than an area of ​​the second layer, and a thickness of the second layer is at least partially thicker at the outer circumferential edge portion than an inside of the outer circumferential edge portion.

7. The power conversion device of claim 1, wherein the cooler has a jacket and a top plate, the refrigerant flow path is defined by the internal space of the jacket and the top plate, the top plate has a first surface facing the internal space and a second surface opposite the first surface, the component is arranged on the second surface, a plurality of fins are formed on the first surface, the first surface has a first region that overlaps with the component in a planar view and a second region that does not overlap with the component in a planar view, the plurality of fins include a first fin formed in the first region and a second fin formed in the second region, and the second fin is longer than the first fin.

8. The power conversion device of claim 1, wherein the cooler has a jacket and a top plate, the refrigerant flow path is defined by an internal space of the jacket and the top plate, the top plate has a first surface facing the internal space and a second surface opposite the first surface, the component is arranged on the second surface, a plurality of fins are formed on the first surface, and at least a portion of the plurality of fins contact the jacket when a flow path area of ​​the refrigerant flow path is reduced.

9. The power conversion device of claim 1, wherein the cooler has a jacket, a top plate, and a plate member, the plate member is disposed in the internal space of the jacket, the refrigerant flow path is defined by the internal space, the top plate, and the plate member, the top plate has a first surface facing the internal space and a second surface opposite the first surface, the component is disposed on the second surface, a plurality of fins are formed on the second surface, and the area of ​​the refrigerant flow path is changed by warping deformation of the plate member due to temperature changes of the component.

10. The power conversion device of claim 1, wherein the cooler has a jacket and a top plate, the refrigerant flow path is defined by the internal space of the jacket and the top plate, the top plate has a first surface facing the internal space and a second surface opposite the first surface, the component is disposed on the second surface, and an area of ​​the refrigerant flow path is changed by warping deformation of the jacket due to a change in temperature of the component.

11. A power conversion device according to any one of claims 1 to 10, wherein the reference temperature is the lowest temperature in the operating temperature range of the component.

12. The power conversion apparatus according to any one of claims 1 to 11, wherein the component is a power device.

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