Power Conversion Device

Abstract

A power conversion device capable of efficiently cooling an inverter section and a DC-DC converter section is provided. [Solution] This power conversion device 100 includes an inverter unit 10, a DC-DC converter unit 30, a boost converter unit 20 that boosts DC power and supplies it to the inverter unit 10, and a flat base unit 50 on whose front and back sides the inverter unit 10, the DC-DC converter unit 30, and the boost converter unit 20 are arranged. The base unit 50 includes a cooling flow path 51 having a front-side flow path 51a arranged on the front side and a back-side flow path 51b connected to the front-side flow path 51a and arranged on the back side, and the boost converter unit 20 and the DC-DC converter unit 30 are arranged side by side in this order along the flow direction of the cooling liquid in the cooling flow path 51.

Description

[Technical Field]

[0001] The present invention relates to a power converter, and more particularly to a power converter having a cooling channel. [Background technology]

[0002] BACKGROUND ART Conventionally, a power conversion device provided with a cooling channel is known (see, for example, Patent Document 1).

[0003] The above-mentioned Patent Document 1 discloses a power conversion device including an inverter, a DC / DC converter, and a cooling channel through which a refrigerant flows to cool the inverter and the DC / DC converter. In this power conversion device, the inverter and the DC / DC converter are arranged on either side of the cooling channel, and the inverter and the DC / DC converter are cooled by the refrigerant flowing in the cooling channel arranged between them. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-027901 Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1, an inverter and a DC / DC converter (a DC / DC converter unit) are arranged on either side of a cooling channel, and are cooled by a refrigerant flowing through the cooling channel arranged between them. As a result, the inverter is cooled by a portion of the refrigerant flowing through the cooling channel on the inverter side, and the DC / DC converter is cooled by a portion of the refrigerant flowing through the cooling channel on the DC / DC converter side. Therefore, if there is a temperature difference between the inverter and the DC / DC converter, a temperature difference will occur between the refrigerants flowing through the same position in the cooling channel, and the temperature difference will cause unintended convection in the refrigerant, making it difficult to perform efficient cooling.

[0006] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a power conversion device that can efficiently cool the inverter section and the DC-DC converter section. [Means for solving the problem]

[0007] In order to achieve the above object, a power conversion device according to a first aspect of the present invention includes an inverter unit that converts DC power input from a DC power source into AC power and supplies the AC power to a load, a DC / DC converter unit that converts a voltage of the DC power into a different voltage, a boost converter unit that is arranged on the input side of the inverter unit and boosts the DC power input from the DC power source and supplies the boosted DC power to the inverter unit, and a flat base unit on the front and back sides of which the inverter unit, the DC / DC converter unit, and the boost converter unit are arranged. 、 The base unit includes a cooling flow path having a front-side flow path arranged on the front side and a back-side flow path connected to the front-side flow path and arranged on the back side, and the boost converter unit and the DC-DC converter unit are ,cold The cooling fluid is arranged along the direction of flow of the cooling fluid in the cooling flow passage. , the boost converter section is arranged upstream of the DC-DC converter section. .

[0008] In a power conversion device according to a first aspect of the present invention, as described above, the inverter unit and the DC / DC converter unit are disposed on the front and back sides of a flat base, and the base is provided with a cooling channel having a front-side channel disposed on the front side and a back-side channel connected to the front-side channel and disposed on the back side. This allows cooling liquid to flow sequentially through the front-side channel and the back-side channel, thereby sequentially cooling the inverter unit and the DC / DC converter unit disposed on the front and back sides of the base. This prevents temperature differences between the cooling liquids flowing through the same location, thereby preventing unintended convection of the cooling liquid due to temperature differences. As a result, the inverter unit and the DC / DC converter unit can be efficiently cooled by the cooling liquid flowing through the cooling channel. Furthermore, the configuration of a power conversion device including the inverter unit and the DC / DC converter unit can be made more compact than when the inverter unit and the DC / DC converter unit are disposed on separate bases and cooled by cooling channels provided in each base.

[0009] In the power converter according to the first aspect, the cooling flow path preferably further includes a connecting flow path that connects the front-side flow path and the back-side flow path within the base. With this configuration, the cooling flow path can be formed within the base so that the cooling liquid flows sequentially through the front-side flow path and the back-side flow path. This simplifies the configuration of the base, unlike when the front-side flow path and the back-side flow path are connected outside the base.

[0010] In the power conversion device according to the first aspect, the cooling flow path is preferably formed such that the front-side flow path and the rear-side flow path are alternately connected and the cooling liquid alternately passes through the front surface and the rear surface of the base. With this configuration, the cooling liquid can be alternately and sequentially flowed through the front-side flow path and the rear-side flow path, thereby alternately and sequentially cooling the inverter unit and the DC-DC converter unit arranged on the front side and the rear side of the base.

[0011] In the power conversion device in which the cooling flow path has a connection flow path, the corners of the connection flow path are preferably chamfered, which makes it possible to suppress an increase in pressure loss at the corners of the connection flow path compared to when the corners of the connection flow path are not chamfered.

[0012] In the power converter having the cooling flow path having a connecting flow path, the connecting flow path preferably includes a partition plate for adjusting the flow of cooling liquid flowing into at least one of the front-side flow path and the back-side flow path.

[0013] In the aforementioned power converter in which the cooling flow passage has the connecting flow passage, the cooling flow passage preferably includes an inclined groove portion in the connecting flow passage.

[0014] In the power converter according to the first aspect, the inverter unit is preferably disposed on one of the front and rear sides of the base and cooled by a cooling liquid flowing through one of the front and rear flow paths, and the DC-DC converter unit is disposed on the other of the front and rear sides of the base and cooled by a cooling liquid flowing through the other of the front and rear flow paths. This configuration allows the components and elements included in the inverter unit to be disposed on one side of the base and the components and elements included in the DC-DC converter unit to be disposed on the other side of the base, thereby reducing the number of wiring lines connecting the front and rear sides of the base. This reduces the complexity of the wiring structure of the power converter.

[0015] In the power conversion device according to the first aspect, the base preferably includes a cooling unit main body made of metal in which a cooling flow path is formed, and a lid made of metal that forms the cooling flow path together with the cooling unit main body, and at least one of the inverter unit and the DC / DC converter unit is attached to the lid located on the front and back sides of the base. With this configuration, the lid to which the inverter unit or the DC / DC converter unit is attached can be brought into direct contact with the cooling liquid flowing through the cooling flow path, thereby efficiently removing heat from the inverter unit and the DC / DC converter unit via the lid.

[0016] In this case, the lid is preferably provided with a protrusion that protrudes into the cooling flow path, and such a configuration increases the area of ​​contact between the lid and the cooling liquid, thereby enabling more efficient transfer of heat from the inverter unit and the DC-DC converter unit to the cooling liquid via the lid.

[0017] In the power conversion device having the protrusion on the lid, the protrusion on the lid is preferably formed in a fin shape, a cylindrical shape, or a prismatic shape. With this configuration, heat can be effectively dissipated from the fin-shaped, cylindrical, or prismatic protrusion to the cooling liquid, and the fin-shaped, cylindrical, or prismatic protrusion can rectify the cooling liquid in the cooling flow path or diffuse it in the width direction of the cooling flow path.

[0018] In this case, the fin-shaped protrusions of the lid are preferably formed to extend along the cooling flow path, so that the fin-shaped protrusions can provide a flow straightening effect for guiding the cooling liquid along the cooling flow path, and can suppress an increase in pressure loss compared to when fins are provided in a direction intersecting the cooling flow path.

[0019] In the power conversion device configured as described above in which a protrusion is provided on the lid, preferably, the lid has multiple protrusions formed thereon, and the multiple protrusions are formed so that their protrusion height is 80 to 100% of the depth direction of the cooling flow path.

[0020] In the power converter having the above-described configuration in which the protrusion is provided on the lid, the protrusion on the lid is preferably formed so that the gap between the protrusion and the wall surface of the cooling flow path is 0.5 to 2.0 mm.

[0021] In the power conversion device according to the first aspect, preferably, the inverter unit includes a first switching element module and a second switching element module that convert DC power to AC power, the DC / DC converter unit includes converter switching elements, a transformer, a resonant reactor, and a smoothing reactor, the boost converter unit includes a boost switching element module and a boost reactor, and the cooling flow path is formed so that the cooling liquid flows so as to cool first components having a higher priority based on heat resistance among the first switching element module, the second switching element module, converter switching elements, the transformer, the resonant reactor, the smoothing reactor, the boost switching element module, and the boost reactor. With this configuration, components with lower heat resistance and that need to be cooled more reliably can be cooled first, thereby reliably preventing the temperature of the components with lower heat resistance from increasing.

[0022] In this case, preferably, the first switching element module and the second switching element module are arranged on one of the front and back sides of the base and are cooled by a cooling liquid flowing through one of the front and back flow paths, and the converter switching elements, the transformer, the resonant reactor, the smoothing reactor, the boost switching element module, and the boost reactor are arranged on the other of the front and back sides of the base and are cooled by a cooling liquid flowing through the other of the front and back flow paths.With this configuration, the first switching element module and the second switching element module of the inverter unit are arranged on one surface of the base, and the converter switching elements, the transformer, the resonant reactor, and the smoothing reactor of the DC-DC converter unit, and the boost switching element module and the boost reactor of the boost converter unit are arranged on the other surface of the base, allowing each component to be effectively cooled.

[0023] In the power conversion device in which the base portion includes a lid portion, the lid portion preferably includes a boost reactor lid portion in which the boost reactor is disposed, and a DC / DC converter lid portion in which the DC / DC converter portion is disposed, and the boost reactor lid portion and the DC / DC converter lid portion are integrally configured.

[0024] In the power conversion device having the base portion including a lid portion, the lid portion preferably includes a boost reactor lid portion on which the boost reactor is disposed, and a DC / DC converter lid portion on which the DC / DC converter portion is disposed, and the boost reactor lid portion and the DC / DC converter lid portion are provided on at least one of the front-side flow path and the back-side flow path, and are fixed to a tunnel-shaped flow path forming member connecting the front-side flow path and the front-side flow path, or connecting the back-side flow path to the back-side flow path.

[0025] In the aforementioned power converter according to the first aspect, the pressure loss of the cooling liquid that cools the DC-DC converter section is preferably set to 15% of the pressure loss of the entire cooling flow path.

[0026] According to a second aspect of the present invention, there is provided a power conversion device comprising a cooler, an inverter unit that converts DC power input from a DC power supply into AC power and supplies the AC power to a load, a DC / DC converter unit that converts the voltage of the DC power into a different voltage, and a boost converter unit that is arranged on the input side of the inverter unit and boosts the DC power input from the DC power supply and supplies the AC power to the inverter unit, wherein the cooler has a unicursal cooling flow path formed therein, and at least a portion of the cooling flow path forms a front-side flow path that cools a front side of the cooler and a back-side flow path that cools a back side of the cooler, and the cooler includes an inverter cooling surface on which the inverter unit is arranged, a DC / DC converter cooling surface on which the DC / DC converter unit is arranged, and a boost converter cooling surface on which the boost converter unit is arranged, and the boost converter unit and the DC / DC converter unit are ,cold The cooling fluid is arranged along the direction of flow of the cooling fluid in the cooling flow passage. , the boost converter section is arranged upstream of the DC-DC converter section. .

[0027] In this case, the cooling body is preferably configured so that the pressure loss of the cooling liquid that cools the inverter cooling surface and the boost converter cooling surface is 85% of the pressure loss of the entire cooling body. [Effects of the Invention]

[0028] According to the present invention, as described above, the inverter section and the DC-DC converter section can be efficiently cooled. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a circuit diagram of a power conversion device according to an embodiment. [Figure 2] 1 is a perspective view of a power converter according to an embodiment; [Figure 3] 1 is a side view of a power converter according to one embodiment; [Figure 4] 1 is an exploded perspective view of a power converter according to an embodiment, viewed from above; [Figure 5] 1 is an exploded perspective view of a power converter according to an embodiment, viewed from below; [Figure 6] FIG. 2 is a top view of a base portion of a power converter according to an embodiment. [Figure 7] FIG. 2 is a bottom view of a base unit of a power converter according to an embodiment. [Figure 8] 2 is a side cross-sectional view of a base portion of a power converter according to one embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0030] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

[0031] The configuration of a power conversion device 100 according to one embodiment of the present invention will be described with reference to Figures 1 to 8. The power conversion device 100 is mounted on a vehicle, for example.

[0032] First, the circuit configuration of a power conversion device 100 will be described with reference to Fig. 1. The power conversion device 100 includes an inverter unit 10. The inverter unit 10 converts DC power input from a DC power supply 200 into AC power and supplies the AC power to a load 210. The load 210 is, for example, a motor. A switch 201 is provided between the power conversion device 100 and the DC power supply 200.

[0033] The inverter unit 10 includes a switching element module 11. The switching element module 11 converts DC power into AC power. The switching element module 11 also includes semiconductor switching elements Q1, Q2, and Q3 that form an upper arm, and semiconductor switching elements Q4, Q5, and Q6 that form a lower arm.

[0034] The inverter unit 10 includes a first inverter unit 10a and a second inverter unit 10b. The switching element module 11 includes a first switching element module 11a included in the first inverter unit 10a and a second switching element module 11b included in the second inverter unit 10b. The load 210 includes a first load 210a and a second load 210b. The first inverter unit 10a converts DC power input from the DC power supply 200 into AC power and supplies it to the first load 210a. The second inverter unit 10b converts DC power input from the DC power supply 200 into AC power and supplies it to the second load 210b.

[0035] The power conversion device 100 includes a boost converter unit 20. The boost converter unit 20 is disposed on the input side of the inverter unit 10. The boost converter unit 20 boosts DC power input from a DC power supply 200 and supplies the boosted power to the inverter unit 10. The boost converter unit 20 includes a boost switching element module 21 and a reactor 22. The boost switching element module 21 includes boost switching elements Q11 and Q12. The boost switching elements Q11 and Q12 form an upper arm and a lower arm, respectively. The boost converter unit 20 also includes a capacitor C1. The reactor 22 is disposed between the positive side of the DC power supply 200 and a connection point between the boost switching element Q11 and the boost switching element Q12. The capacitor C1 is disposed in parallel with the boost switching element Q12. The reactor 22 is an example of a "boosting reactor" in the claims.

[0036] The power conversion device 100 includes a capacitor C2 and a resistor R. The capacitor C2 and the resistor R are provided between the boost converter unit 20 and the inverter unit 10. The capacitor C2 and the resistor R are provided in parallel with each other.

[0037] The power conversion device 100 includes a DC-DC converter unit 30. The DC-DC converter unit 30 converts the voltage of DC power into a different voltage. Specifically, the DC-DC converter unit 30 steps down the voltage of DC power input from a DC power source 200 via a connector 1. The DC-DC converter unit 30 supplies the stepped-down voltage to an output terminal 2. The DC-DC converter unit 30 is an example of a "DC-DC converter unit" in the claims.

[0038] Next, the structure of the power conversion device 100 will be described.

[0039] 2 and 4, the DC-DC converter unit 30 includes a DC-DC converter element 31 and a DC-DC converter substrate 32 on which the DC-DC converter element 31 is mounted. The DC-DC converter substrate 32 has a flat plate shape. The DC-DC converter element 31 mounted on the DC-DC converter substrate 32 includes a converter switching element 31a, a transformer 31b, a resonant reactor 31c, and a smoothing reactor 31d. The converter switching element 31a is provided on the back side (Z2 side) of the DC-DC converter substrate 32. The transformer 31b, the resonant reactor 31c, and the smoothing reactor 31d are provided to penetrate the DC-DC converter substrate 32.

[0040] As shown in FIG. 5, the switching element module 11 houses semiconductor switching elements Q1 to Q6 (see FIG. 1). The semiconductor switching elements Q1 to Q6 are covered by a housing made of resin or the like. As shown in FIG. 4, a lid 12 is disposed on the side (Z1 side) of the switching element module 11 facing a base 50 (described later). The lid 12 is formed of a metal with relatively high thermal conductivity, such as aluminum. The lid 12 includes a flat body 12a and a plurality of pillars 12b protruding toward the base 50. The pillars 12b are formed so as to protrude into the cooling flow path 51. The pillars 12b have, for example, a prismatic shape. The switching element module 11 has a rectangular shape when viewed from a direction perpendicular to the surface of the switching element module 11. The pillars 12b are an example of a "protrusion" in the claims.

[0041] As shown in FIGS. 2 to 5, the power conversion device 100 includes a base unit 50. The base unit 50 is flat. The inverter unit 10 and the DC-DC converter unit 30 are arranged on the base unit 50. The base unit 50 is made of a metal with relatively high thermal conductivity, such as aluminum. The base unit 50 has a rectangular shape when viewed in a direction perpendicular to the front surface 50a (front surface (Z1 side surface)) and the back surface 50b (back surface (Z2 side surface)) of the base unit 50.

[0042] Here, in this embodiment, as shown in FIG. 8, the base portion 50 includes a cooling flow path 51 through which a cooling liquid flows and which has a front-side flow path 51a arranged on the front side and a back-side flow path 51b connected to the front-side flow path 51a and arranged on the back side.

[0043] The cooling flow passage 51 also has a connecting flow passage 51c that connects the front-side flow passage 51a and the back-side flow passage 51b within the base portion 50.

[0044] The switching element modules 11 of the inverter unit 10 are attached to the flat base unit 50 so as to fit along the front surface 50a or the back surface 50b of the flat base unit 50. In addition, the DC-DC converter board 32 on which the DC-DC converter elements 31 are mounted is attached to the base unit 50 so as to fit along the front surface 50a or the back surface 50b of the flat base unit 50.

[0045] Specifically, the switching element module 11 is attached to the base part 50 so as to follow the back surface 50b of the flat base part 50. In addition, the DC-DC converter board 32 on which the DC-DC converter element 31 is mounted is attached to the base part 50 so as to follow the front surface 50a of the flat base part 50.

[0046] The first switching element module 11a and the second switching element module 11b are attached to the base part 50 so as to extend along the rear surface 50b of the flat base part 50. Specifically, the first switching element module 11a and the second switching element module 11b are arranged adjacent to each other along the long side direction (X direction) of the first switching element module 11a and the second switching element module 11b.

[0047] The boost converter unit 20 is attached to the base unit 50 so as to be along the front surface 50a or the back surface 50b of the flat-plate-shaped base unit 50. Specifically, the boost converter unit 20 is attached to the front surface 50a of the base unit 50. The boost converter unit 20 is also arranged adjacent to the DC-DC converter unit 30 along the longitudinal direction (X direction) of the flat-plate-shaped base unit 50.

[0048] The boost converter unit 20 includes a boost switching element module 21 and a reactor 22. The boost switching element module 21 and the reactor 22 are attached to the flat base unit 50 so as to be aligned along the front surface 50a or the back surface 50b of the flat base unit 50. Specifically, the DC-DC converter board 32, the reactor 22, and the boost switching element module 21 are attached to the base unit 50 so as to be aligned along the front surface 50a of the flat base unit 50 and adjacent to each other. The DC-DC converter board 32, the reactor 22, and the boost switching element module 21 are attached to the front surface 50a of the base unit 50 in this order.

[0049] As shown in FIG. 5, a lid 21a is disposed on the base 50 side (Z2 side) of the boost switching element module 21. The lid 21a is made of a metal with relatively high thermal conductivity, such as aluminum. The lid 21a includes a flat body 21b and a plurality of pillars 21c protruding toward the base 50. The pillars 21c are formed so as to protrude into the cooling flow path 51. The pillars 21c have, for example, a cylindrical shape. The boost switching element module 21 has a square shape when viewed from a direction perpendicular to the surface of the boost switching element module 21. The pillars 21c are an example of a "protrusion" in the claims.

[0050] A lid portion 22a is disposed on the base portion 50 side (Z2 side) of the reactor 22. The lid portion 22a is formed of a metal with relatively high thermal conductivity, such as aluminum. The lid portion 22a includes a main body portion 22b and a plurality of fins 22c that protrude toward the base portion 50. The fins 22c are formed to protrude into the cooling flow path 51. The fins 22c are formed to extend along the cooling flow path 51. The fins 22c are an example of a "protrusion" in the claims.

[0051] As shown in FIGS. 4 and 5 , the base 50 includes a cooling unit main body 52 made of metal in which a cooling flow path 51 is formed, and lids 12, 21a, 22a, and 53 made of metal that, together with the cooling unit main body 52, form the cooling flow path 51. The inverter 10 and the DC-DC converter 30 are attached to the lids 12 and 53, which are disposed on the front and back sides of the base 50. Specifically, the DC-DC converter board 32 is attached to the lid 53. Specifically, the cooling flow path 51 is provided on both the front surface 50a and the back surface 50b of the base 50 (see FIGS. 6 and 7 ). The lid 53 covers the cooling flow path 51 provided on the front surface 50a of the base 50. The lid 53 has a rectangular and flat plate shape. The DC-DC converter board 32 is disposed along the front surface 53b of the lid 53. The DC-DC converter board 32 is attached, for example, with screws, to a column 53c provided on the lid 53. The lid 53 is attached, for example, with screws, to the cooling unit main body 52. ​​This makes it possible to easily replace the DC-DC converter board 32 and the DC-DC converter element 31 simply by removing the screws.

[0052] The lid portion 53 is formed of a metal with relatively high thermal conductivity, such as aluminum. The lid portion 53 is provided with fins 53d that protrude into the cooling flow path 51. The fins 53d are formed to extend along the cooling flow path 51. The fins 53d are an example of a "protrusion" in the claims.

[0053] The lid 12 covers the cooling channel 51 provided on the rear surface 50b of the base 50. Two lids 12 are provided. Each lid 12 has a rectangular, flat plate shape. The first switching element module 11a and the second switching element module 11b are attached to the lids 12, respectively.

[0054] The lid 21a covers the cooling flow path 51 provided on the surface 50a of the base 50. The lid 21a has a rectangular, flat plate shape. The boost switching element module 21 is attached to the lid 21a.

[0055] As shown in Fig. 4, the DC-DC converter element 31 includes a converter switching element 31a. The converter switching element 31a is attached to the surface of the DC-DC converter board 32 facing the lid 53 (the surface on the Z2 side) via a heat conductive member 33 so as to be in contact with the lid 53. That is, the lid 53, the heat conductive member 33, and the converter switching element 31a are stacked in this order. Heat generated from the converter switching element 31a is dissipated to the lid 53 via the heat conductive member 33. The heat conductive member 33 is made of, for example, a ceramic sheet.

[0056] Furthermore, a hole 53a is provided in the lid 53. The reactor 22 is arranged to cover the hole 53a of the lid 53. That is, the reactor 22 is arranged to cover the cooling flow path 51. Heat generated from the reactor 22 is dissipated to the cooling liquid flowing through the cooling flow path 51. The reactor 22 is attached to the lid 53 by, for example, a screw.

[0057] A hole 52a is provided in the cooling unit main body 52. ​​The boost switching element module 21 is arranged so as to cover the hole 52a of the cooling unit main body 52. ​​In other words, the boost switching element module 21 is arranged so as to cover the cooling flow path 51. Heat generated from the boost switching element module 21 is dissipated to the cooling liquid flowing through the cooling flow path 51. The boost switching element module 21 is attached to the cooling unit main body 52 with screws, for example.

[0058] 5, a pair of holes 52b are provided in the cooling unit main body 52. ​​The first switching element module 11a and the second switching element module 11b are arranged so as to cover the holes 52b. That is, the first switching element module 11a and the second switching element module 11b are arranged so as to cover the cooling flow path 51. Heat generated from the switching element modules 11 is dissipated to the cooling liquid flowing through the cooling flow path 51.

[0059] 3, cooling flow channels 51 are formed such that front-side flow channels 51a and back-side flow channels 51b are alternately connected, and the cooling liquid alternately passes through the front and back surfaces of base unit 50. Specifically, cooling flow channels 51 are arranged on the front side (front surface 50a side) and include cooling flow channels 511, 515, and 519 as front-side flow channels 51a, and cooling flow channels 513 and 517 as back-side flow channels 51b arranged on the back side (back surface 50b side), and include cooling flow channels 512, 514, 516, and 518 as connecting flow channels 51c. Cooling flow channels 51 are formed such that the cooling fluid flows in from one end side in the longitudinal direction (X direction) of base unit 50 and flows out from the other end side.

[0060] 3, 6, and 7, the cooling liquid flows into the cooling flow passage 51 from the cooling flow passage 511 of the front-side flow passage 51a, passes through the cooling flow passage 512 of the connection flow passage 51c, the cooling flow passage 513 of the back-side flow passage 51b, the cooling flow passage 514 of the connection flow passage 51c, the cooling flow passage 515 of the front-side flow passage 51a, the cooling flow passage 516 of the connection flow passage 51c, the cooling flow passage 517 of the back-side flow passage 51b, the cooling flow passage 518 of the connection flow passage 51c, and the cooling flow passage 519 of the front-side flow passage 51a before flowing out.

[0061] The cooling liquid flowing out of the cooling flow path 51 is cooled by heat dissipation by the heat dissipation unit 60. The cooling liquid cooled by the heat dissipation unit 60 is sent by the pump 61 and flows back into the cooling flow path 51. The heat dissipation unit 60 includes a heat exchanger and is cooled by external air. The heat dissipation unit 60 is, for example, a radiator. The pump 61 may be disposed between the outlet of the cooling flow path 51 and the heat dissipation unit 60, and the cooling liquid before its heat is dissipated by the heat dissipation unit 60 may be sent by the pump 61. The cooling liquid may be, for example, water, antifreeze, or other liquid.

[0062] 3, the inverter unit 10 is disposed on the back side of the base unit 50 and is cooled by the cooling liquid flowing through the back-side flow path 51b. Specifically, the first switching element module 11a and the second switching element module 11b are disposed on the back side of the base unit 50 and are cooled by the cooling liquid flowing through the back-side flow path 51b.

[0063] In this embodiment, the DC-DC converter unit 30 is disposed on the front side of the base unit 50 and is cooled by the cooling liquid flowing through the front-side flow path 51a. Specifically, the converter switching element 31a, the transformer 31b, the resonant reactor 31c, the smoothing reactor 31d, the boost switching element module 21, and the reactor 22 are disposed on the front side of the base unit 50 and are cooled by the cooling liquid flowing through the front-side flow path 51a.

[0064] In this embodiment, the corners of the connection flow path 51c are chamfered as shown in Fig. 8. Specifically, chamfered portions 510 are provided at the portion of the connection flow path 51c that connects to the front-side flow path 51a and the portion that connects to the back-side flow path 51b.

[0065] In this embodiment, the cooling flow path 51 is formed so that the cooling liquid flows to first cool the components having higher priority based on heat resistance among the first switching element module 11a, the second switching element module 11b, the converter switching element 31a, the transformer 31b, the resonant reactor 31c, the smoothing reactor 31d, the boost switching element module 21, and the reactor 22. Specifically, the cooling flow path 51 is formed so that the boost switching element module 21 and the reactor 22, which have relatively low heat resistance, are cooled on the upstream side.

[0066] In addition, the cooling flow path 51 is formed so that the cooling liquid flows to cool the boost switching element module 21, the second switching element module 11b, the reactor 22, the resonant reactor 31c, the converter switching element 31a, the transformer 31b, the first switching element module 11a, and the smoothing reactor 31d in that order.

[0067] 3, 6, and 7, the boost switching element module 21 is cooled by the cooling liquid flowing through a cooling flow path 511. The second switching element module 11b is cooled by the cooling liquid flowing through a cooling flow path 513. The resonant reactor 31c, the converter switching element 31a, and the transformer 31b are cooled by the cooling liquid flowing through a cooling flow path 515. The first switching element module 11a is cooled by the cooling liquid flowing through a cooling flow path 517. The smoothing reactor 31d is cooled by the cooling liquid flowing through a cooling flow path 519.

[0068] [Effects of this embodiment] In this embodiment, the following effects can be obtained.

[0069] In this embodiment, as described above, the inverter unit 10 and the DC-DC converter unit 30 are disposed on the front and back sides of the flat base unit 50. The base unit 50 is provided with a cooling channel 51 having a front-side channel 51a disposed on the front side and a back-side channel 51b connected to the front-side channel 51a and disposed on the back side. This allows the cooling liquid to flow sequentially through the front-side channel 51a and the back-side channel 51b, thereby sequentially cooling the inverter unit 10 and the DC-DC converter unit 30 disposed on the front and back sides of the base unit 50. This prevents temperature differences between the cooling liquids flowing through the same location, thereby preventing unintended convection of the cooling liquid due to temperature differences. As a result, the cooling liquid flowing through the cooling channel 51 efficiently cools the inverter unit 10 and the DC-DC converter unit 30. Furthermore, compared to a configuration in which the inverter unit 10 and the DCDC converter unit 30 are placed on separate base units and cooled by cooling flow paths provided in each base unit, the configuration of the power conversion device 100 equipped with the inverter unit 10 and the DCDC converter unit 30 can be made more compact.

[0070] Furthermore, in this embodiment, as described above, the cooling flow path 51 has the connecting flow path 51c that connects the front-side flow path 51a and the back-side flow path 51b within the base part 50. This allows the cooling flow path 51 to be formed within the base part 50 so that the cooling liquid flows sequentially through the front-side flow path 51a and the back-side flow path 51b. Therefore, unlike the case where the front-side flow path 51a and the back-side flow path 51b are connected outside the base part 50, the configuration of the base part 50 can be simplified.

[0071] Furthermore, in this embodiment, as described above, the cooling flow path 51 is formed such that the front-side flow paths 51a and the back-side flow paths 51b are alternately connected, and the cooling liquid alternately passes through the front surface and the back surface of the base part 50. This allows the cooling liquid to alternately and sequentially flow through the front-side flow paths 51a and the back-side flow paths 51b, and therefore the inverter unit 10 and the DC-DC converter unit 30 arranged on the front side and the back side of the base part 50 can be alternately and sequentially cooled.

[0072] In addition, in this embodiment, as described above, the inverter unit 10 is disposed on the back side of the base unit 50 and is cooled by the cooling liquid flowing through the back-side flow path 51b, and the DC-DC converter unit 30 is disposed on the front side of the base unit 50 and is cooled by the cooling liquid flowing through the front-side flow path 51a. This allows the components and elements included in the inverter unit 10 to be disposed on the back surface of the base unit 50, and the components and elements included in the DC-DC converter unit 30 to be disposed on the front surface of the base unit 50, thereby preventing an increase in the number of wirings connecting the front and back sides of the base unit 50. This prevents the wiring structure of the power conversion device 100 from becoming complicated.

[0073] In this embodiment, as described above, the base 50 includes the cooling unit main body 52 made of metal in which the cooling flow path 51 is formed, and the lids 12, 21a, 22a, and 53 made of metal that form the cooling flow path 51 together with the cooling unit main body 52. ​​The inverter 10 and the DC-DC converter 30 are attached to the lids 12 and 53 that are located on the front and back sides of the base 50. This allows the lids 12 and 53 to which the inverter 10 and the DC-DC converter 30 are attached to come into direct contact with the cooling liquid flowing through the cooling flow path 51, thereby efficiently removing heat from the inverter 10 and the DC-DC converter 30 via the lids 12 and 53.

[0074] Furthermore, in this embodiment, as described above, the lid portions 12, 21a, 22a, and 53 are provided with protrusions (pillar portions 12b, 21c, fins 22c, and 53d) that protrude into the cooling flow path 51. This allows the protrusions (pillar portions 12b, 21c, fins 22c, and 53d) to increase the area of ​​the lid portions 12, 21a, 22a, and 53 that come into contact with the cooling liquid, so that heat from the inverter portion 10 and the DC-DC converter portion 30 can be more efficiently transferred to the cooling liquid via the lid portions 12, 21a, 22a, and 53.

[0075] In this embodiment, as described above, the protrusions (pillars 12b, 21c, fins 22c, 53d) of the lids 12, 21a, 22a, 53 are formed in a fin-like, cylindrical, or prismatic shape. This allows heat to be effectively dissipated from the fin-shaped, cylindrical, or prismatic protrusions (pillars 12b, 21c, fins 22c, 53d) to the cooling liquid, and the fin-shaped, cylindrical, or prismatic protrusions (pillars 12b, 21c, fins 22c, 53d) allow the cooling liquid in the cooling flow channel 51 to be rectified or diffused in the width direction of the cooling flow channel 51.

[0076] Furthermore, in this embodiment, as described above, the fins 22c and 53d of the lid portions 22a and 53 are formed to extend along the cooling flow path 51. This allows the fins 22c and 53d to achieve a flow straightening effect that guides the cooling liquid along the cooling flow path 51, and also prevents pressure loss from increasing compared to when the fins are provided in a direction intersecting the cooling flow path 51.

[0077] In addition, in this embodiment, as described above, the corners of the connection flow passage 51c are chamfered, which makes it possible to prevent pressure loss at the corners of the connection flow passage 51c from increasing compared to when the corners of the connection flow passage 51c are not chamfered.

[0078] As described above, this embodiment also includes a boost converter unit 20 that is disposed on the input side of the inverter unit 10 and boosts DC power input from a DC power supply and supplies the boosted power to the inverter unit 10. The inverter unit 10 also includes a first switching element module 11a and a second switching element module 11b that convert DC power to AC power. The DC-DC converter unit 30 also includes a converter switching element 31a, a transformer 31b, a resonant reactor 31c, and a smoothing reactor 31d. The boost converter unit 20 also includes a boost switching element module 21 and a reactor 22. The cooling flow path 51 is configured so that the cooling liquid flows through the first switching element module 11a, the second switching element module 11b, the converter switching element 31a, the transformer 31b, the resonant reactor 31c, the smoothing reactor 31d, the boost switching element module 21, and the reactor 22, cooling them first in order of priority based on heat resistance. This allows components with low heat resistance that need to be cooled reliably to be cooled first, thereby reliably preventing the temperature of the components with low heat resistance from rising.

[0079] Furthermore, in this embodiment, as described above, the first switching element module 11a and the second switching element module 11b are arranged on the back side of the base unit 50 and are cooled by the cooling liquid flowing through the back-side flow path 51b, while the converter switching element 31a, the transformer 31b, the resonant reactor 31c, the smoothing reactor 31d, the boost switching element module 21, and the reactor 22 are arranged on the front side of the base unit 50 and are cooled by the cooling liquid flowing through the front-side flow path 51a. As a result, the first switching element module 11a and the second switching element module 11b of the inverter unit 10 are arranged on the back surface of the base unit 50, and the converter switching element 31a, the transformer 31b, the resonant reactor 31c, the smoothing reactor 31d of the DC-DC converter unit 30, and the boost switching element module 21 and the reactor 22 of the boost converter unit 20 are arranged on the front surface of the base unit 50, allowing each component to be effectively cooled.

[0080] [Variations] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims rather than the above description of the embodiments, and further includes all modifications (variations) within the meaning and scope of the claims.

[0081] In the above embodiment, an example has been shown in which the switching element module 11 is attached to the rear surface 50b of the base part 50 and the DC-DC converter board 32 is attached to the front surface 50a of the base part 50, but the present invention is not limited to this. For example, the switching element module 11 may be attached to the front surface 50a of the base part 50 and the DC-DC converter board 32 may be attached to the rear surface 50b of the base part 50. Alternatively, both the switching element module 11 and the DC-DC converter board 32 may be attached to the front surface 50a of the base part 50. Alternatively, both the switching element module 11 and the DC-DC converter board 32 may be attached to the rear surface 50b of the base part 50.

[0082] In the above embodiment, the first switching element module 11a and the second switching element module 11b are both attached to the back surface 50b of the base part 50, but the present invention is not limited to this. For example, the first switching element module 11a and the second switching element module 11b may be attached to different surfaces of the base part 50.

[0083] In the above embodiment, the boost converter unit 20 is attached to the front surface 50a of the base unit 50, but the present invention is not limited to this. For example, the boost converter unit 20 may be attached to the back surface 50b of the base unit 50.

[0084] In the above embodiment, an example has been shown in which the boost switching element module 21 and the reactor 22 are both attached to the front surface 50a of the base part 50, but the present invention is not limited to this. For example, the boost switching element module 21 and the reactor 22 may both be attached to the back surface 50b of the base part 50. Furthermore, the boost switching element module 21 and the reactor 22 may be attached to different surfaces of the base part 50.

[0085] In the above embodiment, an example has been described in which the base 50 is separated into the cooling unit main body 52 and the lid 53, but the present invention is not limited to this. For example, the base 50 may be configured such that the cooling unit main body 52 and the lid 53 are integrally formed without being separated.

[0086] In the above embodiment, the DC-DC converter elements 31 mounted on the DC-DC converter board 32 include the converter switching elements 31a, the transformer 31b, the resonant reactor 31c, and the smoothing reactor 31d, but the present invention is not limited to this. For example, the DC-DC converter elements 31 mounted on the DC-DC converter board 32 may include elements other than these elements.

[0087] In the above embodiment, the cooling flow path 51 is formed so that the cooling liquid flows to cool the boost switching element module 21, the second switching element module 11b, the reactor 22, the resonant reactor 31c, the converter switching element 31a, the transformer 31b, the first switching element module 11a, and the smoothing reactor 31d in that order, but the present invention is not limited to this. For example, the cooling flow path 51 may be formed so that the cooling liquid flows to cool the multiple components in an order other than the above.

[0088] In the above embodiment, more specifically, the power converter has a plurality of protrusions formed on the cover 12, 21a, 53, each of which has a protrusion height of 80 to 100% of the depth of the flow path 51 formed in the base 50 (cooling body). Preferably, the plurality of protrusions are formed to a protrusion height of 80 to 93% of the depth of the cooling flow path. Specifically, the gap between the protrusion and the flow path is 0.0 mm to 1.5 mm. The flow path depth is the length measured perpendicularly from the side surface of the flow path in the cover to the bottom surface of the flow path. This configuration is expected to improve heat dissipation.

[0089] In the above embodiment, more specifically, the protrusions of the lids 12, 21a, and 53 are formed so that the gap between the protrusions and the wall surfaces of the flow paths is 0.5 mm to 2.0 mm. With this configuration, improvement in heat dissipation can be expected.

[0090] In other words, in the above embodiment, the base unit 50 (cooling body) may have a flow path formed in a single stroke. At least a portion of the flow path may form a front-side flow path that cools the front side of the cooling body and a back-side flow path that cools the back side. This configuration eliminates the need for a design to evenly divide the flow, such as a flow dividing plate, compared to a flow path that divides the flow in parallel on the front and back. This is expected to reduce the cost of the power conversion device.

[0091] Also, preferably, the flow paths formed in the base part 50 are configured so that the pressure loss of the cooling liquid that cools the DC-DC converter part is 15% of the pressure loss of the entire flow paths formed in the base part 50. With this configuration, it is expected that the heat dissipation performance of the parts that take priority over the DC-DC converter part will be improved.

[0092] In other words, the power conversion device further includes an inverter unit that converts DC power input from a DC power source into AC power and supplies the AC power to a load, a DC / DC converter unit that converts the voltage of the DC power into a different voltage, and a boost converter unit that is arranged on the input side of the inverter unit and boosts the DC power input from the DC power source and supplies the boosted DC power to the inverter unit, and the cooling body includes an inverter cooling surface on which the inverter unit is arranged, a converter cooling surface on which the DC / DC converter unit is cooled, and a boost converter cooling surface on which the boost converter unit is arranged. By using such a configuration, it is expected that the power conversion device can be made smaller.

[0093] In other words, the cooling body is configured so that the pressure losses of the cooling liquid cooling the inverter cooling surface, the boost converter cooling surface, and the converter cooling surface are 85% and 15%, respectively, of the pressure loss of the entire cooling body. This configuration is expected to improve the heat dissipation of the inverter section and the boost converter section, with priority given to the DC-DC converter section.

[0094] In other words, the power converter includes a connecting flow path that includes a partition plate that adjusts the flow of cooling liquid flowing into at least one of the front-side flow path and the back-side flow path. Specifically, ribs are provided on the connecting flow path to ensure that the cooling liquid is supplied thoroughly to the front-side flow path or the back-side flow path into which it flows. As shown in FIG. 6, flow path 514 is provided with ribs so that the opening ratio is 3-4:1 from the left. Flow path 518 is provided with ribs so that the opening ratio is 2.4-2.7:1.5-1.8:1 from the left.

[0095] In other words, the cooling flow path is a power converter including an inclined groove in the connecting flow path. Specifically, a groove (not shown) inclined relative to flow path 514 in FIG. 7 is provided at the bottom of flow path 513. The groove is preferably provided near the wall surface of the flow path.

[0096] In other words, the above embodiment is a power conversion device in which the lid includes a boost reactor lid in which a boost reactor is disposed and a DC / DC converter lid in which a DC / DC converter is disposed, and the boost reactor lid and the DC / DC converter lid are integrally configured. As shown in Fig. 5, the lid 53 is configured so that the reactor 22 and the DC / DC converter are disposed.

[0097] In other words, the power converter includes a boost reactor cover in which a boost reactor is disposed and a DC / DC converter cover in which a DC / DC converter is disposed. The boost reactor cover and the DC / DC converter cover are provided on at least one of the front-side flow path and the back-side flow path and are fixed to a tunnel-shaped channel-forming member connecting the front-side flow path and the front-side flow path or the back-side flow path and the back-side flow path. More specifically, if the boost reactor cover and the DC / DC converter cover are configured separately, the periphery of each cover must be fixed to the cooling body main body and sealed. As shown in FIG. 4, if the cover 53 is separated into the boost reactor cover and the DC / DC converter cover, the cooling channel 515 straddles the boost reactor cover and the DC / DC converter cover, making it impossible to seal. Therefore, a tunnel-shaped channel-forming member is provided in the cooling channel 515.

[0098] In the above embodiment, a power conversion device including a DC-DC converter unit has been described, but the same effect can be obtained even when the DC-DC converter unit is not mounted on the base unit 50. [Explanation of symbols]

[0099] 10 Inverter section 11a first switching element module 11b Second switching element module 12 Lid 12b Pillar part (protruding part) 20 Boost converter section 21 Boost switching element module 21a Lid 21c Pillar part (protruding part) 22 Reactor (step-up reactor) 22a Fin (protrusion) 30 DC / DC converter section (DC / DC converter section) 31a Converter switching element 31b Trans 31c Resonant reactor 31d Smoothing reactor 50 Base 51 Cooling channel 51a Surface flow path 51b Back side channel 51c Connecting channel 52 Cooling unit main body 53 Lid 53d Fin (protrusion) 100 Power conversion device 200 DC power supply 210 Load 511, 512, 513, 514, 515, 516, 517, 518, 519 Cooling channels

Claims

1. an inverter unit that converts DC power input from a DC power source into AC power and supplies the AC power to a load; a DC-DC converter unit that converts the voltage of the DC power into a different voltage; a boost converter unit that is disposed on an input side of the inverter unit and boosts the DC power input from the DC power supply and supplies the boosted DC power to the inverter unit; a flat base portion on the front and back sides of which the inverter portion, the DC / DC converter portion, and the boost converter portion are arranged, the base portion includes a cooling flow path having a front-side flow path disposed on a front side and a back-side flow path connected to the front-side flow path and disposed on a back side, a power conversion device in which the boost converter unit and the DC-DC converter unit are arranged along a direction in which the cooling liquid flows in the cooling flow path, and the boost converter unit is arranged upstream of the DC-DC converter unit.

2. The power conversion device according to claim 1 , wherein the cooling flow path further includes a connecting flow path that connects the front-side flow path and the back-side flow path within the base portion.

3. 3. The power conversion device according to claim 1, wherein the cooling flow path is formed such that the front-side flow path and the back-side flow path are alternately connected, and the cooling liquid alternately passes through the front surface and the back surface of the base portion.

4. The power conversion device according to claim 2 , wherein corners of the connection flow passage are chamfered.

5. The power conversion device according to claim 2 , wherein the connection flow path includes a partition plate that adjusts the flow of the cooling liquid that flows into at least one of the front-side flow path and the back-side flow path.

6. The power converter according to claim 2 , 4 or 5 , wherein the cooling flow passage includes an inclined groove in the connecting flow passage.

7. the inverter unit is disposed on one of the front side and the back side of the base unit, and is cooled by a cooling liquid flowing through one of the front-side flow path and the back-side flow path; The power conversion device according to any one of claims 1 to 6, wherein the DC-DC converter unit is arranged on the other of the front side and the back side of the base unit, and is cooled by a cooling liquid flowing through the other of the front side flow path and the back side flow path.

8. the base includes a cooling unit main body made of a metal in which the cooling flow path is formed, and a lid made of a metal that forms the cooling flow path together with the cooling unit main body, The power conversion device according to any one of claims 1 to 7, wherein at least one of the inverter unit and the DC-DC converter unit is attached to the lid unit arranged on the front and back sides of the base unit.

9. The power conversion device according to claim 8 , wherein the lid portion is provided with a protrusion that protrudes into the cooling flow path.

10. The power conversion device according to claim 9 , wherein the protrusion of the lid portion is formed in a fin shape, a cylindrical shape, or a prismatic shape.

11. The power conversion device according to claim 10 , wherein the fin-shaped protrusion of the lid portion is formed so as to extend along the cooling flow path.

12. The protrusion of the lid is formed in plurality, The power conversion device according to any one of claims 9 to 11, wherein the plurality of protrusions are formed so as to have a protruding height that is 80 to 100% of the depth of the cooling flow path.

13. The power conversion device according to any one of claims 9 to 12, wherein the protrusion of the lid is formed so that a gap between the protrusion and a wall surface of the cooling flow path is 0.5 to 2.0 mm.

14. the inverter unit includes a first switching element module and a second switching element module that convert the DC power into the AC power, the DC-DC converter unit includes a converter switching element, a transformer, a resonant reactor, and a smoothing reactor, the boost converter unit includes a boost switching element module and a boost reactor, 14. The power conversion device according to claim 1, wherein the cooling flow path is formed to allow a cooling liquid to flow so as to first cool a component having a higher priority based on heat resistance among the first switching element module, the second switching element module, the converter switching element, the transformer, the resonant reactor, the smoothing reactor, the boost switching element module, and the boost reactor.

15. the first switching element module and the second switching element module are disposed on one of the front side and the back side of the base portion and are cooled by a cooling liquid flowing through one of the front side flow path and the back side flow path; 15. The power conversion device according to claim 14, wherein the converter switching element, the transformer, the resonant reactor, the smoothing reactor, the boost switching element module, and the boost reactor are arranged on the other of the front side and the back side of the base, and are cooled by a cooling liquid flowing through the other of the front-side flow path and the back-side flow path.

16. the lid portion includes a boost reactor lid portion on which a boost reactor is disposed, and a DC / DC converter lid portion on which the DC / DC converter portion is disposed, The power conversion device according to any one of claims 8 to 13, wherein the boost reactor cover and the DC / DC converter cover are integrally formed.

17. the lid portion includes a boost reactor lid portion on which a boost reactor is disposed, and a DC / DC converter lid portion on which the DC / DC converter portion is disposed, The power conversion device according to any one of claims 8 to 13, wherein the boost reactor lid and the DC-DC converter lid are provided on at least one of the front-side flow path and the back-side flow path, and are fixed to a tunnel-shaped flow path forming member connecting the front-side flow path and the front-side flow path, or connecting the back-side flow path to the back-side flow path.

18. The power conversion device according to any one of claims 1 to 17, wherein the pressure loss of the cooling liquid that cools the DC-DC converter section is configured to be 15% of the pressure loss of the entire cooling flow path.

19. A cooling body; an inverter unit that converts DC power input from a DC power source into AC power and supplies the AC power to a load; a DC-DC converter unit that converts the voltage of the DC power into a different voltage; a boost converter unit that is arranged on an input side of the inverter unit and boosts the DC power input from the DC power supply and supplies the boosted DC power to the inverter unit, The cooling body has a cooling flow path formed in a single stroke, At least a portion of the cooling flow path forms a front-side flow path that cools a front side of the cooling body and a back-side flow path that cools a back side of the cooling body, the cooling body includes an inverter cooling surface on which the inverter unit is arranged, a DC / DC converter cooling surface on which the DC / DC converter unit is arranged, and a boost converter cooling surface on which the boost converter unit is arranged, a power conversion device in which the boost converter unit and the DC-DC converter unit are arranged along a direction in which the cooling liquid flows in the cooling flow path, and the boost converter unit is arranged upstream of the DC-DC converter unit.

20. 20. The power conversion device of claim 19, wherein the cooling body is configured so that a pressure loss of the cooling liquid that cools the inverter cooling surface, the DC-DC converter cooling surface, and the boost converter cooling surface is 85% of a pressure loss of the entire cooling body.

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