Power Conversion Equipment

Abstract

To provide a power conversion apparatus capable of efficiently cooling an inverter unit and a converter unit.SOLUTION: A power conversion apparatus (100) comprises a converter unit (10), an inverter unit (20), and a cooler unit (30). The cooler unit (30) has therein a cooling flow path (310) including an inverter-side flow path (310a) and a converter-side flow path (310b) connected to the inverter-side flow path (310a). In the cooling flow path (310), the inverter-side flow path (310a) and the converter-side flow path (310b) are connected such that a cooling liquid passes through the entire inverter-side flow path (310a) and then passes through the converter-side flow path (310b).SELECTED DRAWING: Figure 2

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] 2. Description of the Related Art Conventionally, a power conversion device having a cooling flow passage 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 flow path through which a coolant flows to cool the inverter and the DC / DC converter. In this power conversion device, the inverter and the DC / DC converter are disposed on either side of the cooling flow path, and the inverter and the DC / DC converter are cooled by the coolant flowing through the cooling flow path. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2009-027901 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the above Patent Document 1, an inverter and a DC / DC converter (a direct current-direct current converter section) are arranged on either side of a cooling flow path, and the inverter and the DC / DC converter are cooled by a coolant flowing through the cooling flow path. Therefore, of the coolant flowing through the cooling flow path, the inverter is cooled by a portion of the coolant flowing on the inverter side, and the DC / DC converter is cooled by a portion of the coolant flowing on the DC / DC converter side. This causes a problem in that it is 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 capable of efficiently cooling an inverter section and a converter section. [Means for solving the problem]

[0007] In order to achieve the above object, a power conversion device according to one aspect of the present invention includes a converter unit that transforms DC power input from a DC power source, and a power converter unit that converts the DC power transformed by the converter unit into AC power and supplies the AC power to a load. and a first switching element module and a second switching element module for converting DC power to AC power. An inverter unit and a power supply unit disposed between the inverter unit and the converter unit and has an inlet through which the cooling liquid flows and an outlet through which the cooling liquid flows out. A cooling unit, A first inverter flow path provided in correspondence with the first switching element module and a second inverter flow path provided in correspondence with the second switching element module. The cooling system includes a cooling passage including an inverter side passage and a converter side passage connected to the inverter side passage, The inverter includes a main body in which an inverter-side flow path and a converter-side flow path are formed, and a flat first inverter lid and a flat second inverter lid to which a first switching element module and a second switching element module are attached, forming the first inverter flow path and the second inverter flow path, and at least one of the first inverter flow path and the second inverter flow path is provided. for, The main body is provided with a protruding portion toward the inverter side flow path, A plurality of protrusions are provided to protrude toward the inverter unit and adjust the flow of the cooling liquid, and the cooling flow passage is configured so that the cooling liquid passes through the entire inverter side flow passage before passing through the converter side flow passage. inlet, Inverter side flow path 、 Converter side flow path , and the outlet, in this order: is connected.

[0008] In the power conversion device according to the above aspect, as described above, the cooling unit disposed between the inverter unit and the converter unit has a cooling flow path therein including an inverter-side flow path and a converter-side flow path connected to the inverter-side flow path. This allows the inverter unit and the converter unit to be individually cooled by sequentially flowing the cooling liquid through the inverter-side flow path and the converter-side flow path. As a result, it is possible to suppress the occurrence of a temperature difference in the cooling liquid flowing through the same flow path, and therefore it is possible to suppress the occurrence of unintended convection of the cooling liquid caused by the temperature difference. This allows the inverter unit and the converter unit to be efficiently cooled by the cooling liquid flowing through the cooling flow path. In addition, since the cooling flow path is connected to the inverter-side flow path and the converter-side flow path such that the cooling liquid passes through the entire inverter-side flow path before passing through the converter-side flow path, the inverter unit can be cooled more efficiently than when the cooling liquid passes through the inverter-side flow path after passing through the converter-side flow path. In addition, since the inverter lid portion to which the inverter portion is attached can be brought into direct contact with the cooling liquid flowing through the inverter side flow path, heat generated by the inverter portion can be efficiently dissipated via the inverter lid portion. In addition, the multiple protrusions protruding into the cooling flow path adjust the flow of the cooling liquid and increase the flow rate of the cooling liquid flowing in the inverter side flow path. As a result, the inverter section can be cooled efficiently. In addition, the multiple protrusions increase the heat dissipation area (heat transfer area) in the inverter side flow path, so the inverter section can be cooled more efficiently. In addition, the multiple protrusions can increase the flow rate of the cooling liquid, allowing efficient cooling of the inverter section. In addition, the multiple protrusions increase the heat dissipation area (heat transfer area) in the inverter-side flow path, allowing more efficient cooling of the inverter section. In addition, the multiple protrusions can increase the flow rate of the cooling liquid, allowing efficient cooling of the inverter section. In addition, the multiple protrusions increase the heat dissipation area (heat transfer area) in the inverter-side flow path, allowing more efficient cooling of the inverter section.

[0009] In the power converter according to the above aspect, the cooling flow passage is preferably disposed at one end side in the longitudinal direction of the cooling unit, and further includes a first connection flow passage that connects the inverter side flow passage and the converter side flow passage within the cooling unit. With this configuration, the inverter side flow passage and the converter side flow passage are connected within the cooling unit by the first connection flow passage, so that the cooling flow passage can be formed so that the cooling liquid flows sequentially. As a result, unlike the case where the inverter side flow passage and the converter side flow passage are connected outside the cooling unit, the configuration of the cooling unit can be simplified. Furthermore, when there is a single first connection flow passage, the inverter side flow passage and the converter side flow passage are connected by the single first connection flow passage, so that the configuration of the cooling unit can be simplified more than when the inverter side flow passage and the converter side flow passage are connected by a plurality of flow passages.

[0010] In this case, preferably ,cold The cooling flow path is formed by connecting the inlet, the inverter-side flow path, the first connection flow path, the converter-side flow path, and the outlet in this order, and folding back at the first connection flow path arranged at one end in the longitudinal direction. With this configuration, it is possible to suppress an increase in the size of the cooling section in the longitudinal direction compared to a case in which the inlet, the inverter-side flow path, the first connection flow path, the converter-side flow path, and the outlet are linearly connected along the longitudinal direction. Also, it is possible to further simplify the configuration of the cooling section compared to a case in which the inverter-side flow path and the converter-side flow path are alternately connected.

[0011] In the above-mentioned configuration in which the cooling unit has an inlet and an outlet, the cooling flow path is preferably formed such that the inverter-side flow path and the converter-side flow path overlap each other when viewed from the opposing direction in which the inverter unit and the cooling unit face each other. With this configuration, it is possible to suppress an increase in the size of the cooling unit in a direction perpendicular to the opposing direction, compared to a case in which the cooling flow paths are formed such that the inverter-side flow path and the converter-side flow path do not overlap when viewed from the opposing direction.

[0012] In the above-mentioned configuration in which the cooling unit has an inlet and an outlet, preferably, the inverter-side flow path is formed linearly along the longitudinal direction when viewed from the opposing direction in which the inverter unit and the cooling unit are opposed, and the converter-side flow path is formed such that the flow of the cooling liquid meanders when viewed from the opposing direction. With this configuration, since the inverter-side flow path is formed linearly along the longitudinal direction of the cooling unit, it is possible to suppress the inverter-side flow path from becoming complicated and simplify the configuration of the cooling unit. Furthermore, since the converter-side flow path is formed such that the flow of the cooling liquid meanders, the converter unit can be cooled more efficiently by making the flow of the cooling liquid in the converter-side flow path meander depending on the region in which the converter unit is arranged.

[0013] In this case, the cooling flow path is preferably formed so as to branch the cooling liquid into a plurality of flow paths inside the converter-side flow path. With this configuration, the cooling liquid flowing through the converter-side flow path can be diffused over a wider area. As a result, the cooling liquid can be distributed evenly throughout the converter-side flow path, and the converter section can be cooled more efficiently.

[0014] In the above-mentioned configuration in which the cooling unit has an inlet and an outlet, the inlet and the outlet are preferably both provided on the other end side in the longitudinal direction of the cooling unit. With this configuration, the pipes connected to the power conversion device for inflowing and outflowing the cooling liquid are both connected to the other end side in the longitudinal direction of the cooling unit, so that an increase in the longitudinal size of the power conversion device including the pipes can be suppressed compared to a case in which the pipes are connected to both one end side and the other end side in the longitudinal direction of the cooling unit.

[0017] In the above-mentioned configuration in which the cooling portion has an inlet and an outlet, preferably , long The first inverter flow path and the second inverter flow path, which are arranged linearly along the longitudinal direction, are connected to each other. With this configuration, the first switching element module and the second switching element module can be individually cooled by the cooling liquid flowing through each of the first inverter flow path and the second inverter flow path. As a result, the first switching element module and the second switching element module can be cooled more efficiently than when both the first switching element module and the second switching element module are cooled by the cooling liquid flowing through the same flow path.

[0018] In the above-mentioned configuration in which the first inverter flow path and the second inverter flow path are connected to each other, the cooling flow path preferably further includes a second connection flow path that is curved toward the side where the converter unit is disposed and connects the first inverter flow path and the second inverter flow path. With this configuration, the first inverter flow path and the second inverter flow path can be connected by the second connection flow path so as to detour to the side where the converter unit is disposed. As a result, the first inverter flow path and the second inverter flow path can be more easily connected depending on the arrangement and shape of the first inverter flow path and the second inverter flow path compared to the case where the first inverter flow path and the second inverter flow path are connected by a linear flow path.

[0019] In the above-mentioned configuration in which the first inverter flow path and the second inverter flow path are connected to each other, the second inverter flow path is preferably arranged downstream of the first inverter flow path, and the multiple convex portions are provided in the second inverter flow path.

[0020] In this case, preferably, the plurality of convex portions are provided in the second inverter flow path so as to protrude into the second inverter flow path and adjust the flow of the cooling liquid. With this configuration, the plurality of convex portions protruding into the second inverter flow path can adjust the flow of the cooling liquid flowing in the second inverter flow path and increase the flow rate of the cooling liquid flowing in the second inverter flow path. As a result, the second switching element module can be cooled efficiently. In addition, compared to the case where the plurality of convex portions are provided in both the first inverter flow path and the second inverter flow path, it is possible to suppress the structure of the inverter side flow path in the cooling unit from becoming complicated and the weight of the cooling unit from increasing due to the increase in the plurality of convex portions. In addition, the plurality of convex portions increases the heat dissipation area (heat transfer area) in the second inverter flow path, so that the second switching element module can be cooled more efficiently.

[0021] In the above-mentioned configuration in which the first inverter flow path and the second inverter flow path are connected to each other, the second inverter flow path is preferably disposed downstream of the first inverter flow path, and the second inverter flow path has a flow path depth smaller than that of the first inverter flow path. With this configuration, the cross-sectional area of ​​the second inverter flow path can be made smaller than that of the first inverter flow path, so that the flow rate of the cooling liquid flowing through the second inverter flow path can be made faster than the flow rate of the cooling liquid flowing through the first inverter flow path. As a result, the second switching element module can be cooled more efficiently by the second inverter flow path than the first switching element module is cooled by the first inverter flow path. This allows the second switching element module to be sufficiently cooled even when the second switching element module generates more heat than the first switching element module.

[0022] In the above-mentioned configuration in which the cooling unit includes a main body and an inverter lid, preferably, the cooling unit further includes a converter lid that forms, together with the main body, a converter-side flow path that meanders when viewed from the opposing direction, the converter unit is attached to the converter lid, and the converter lid is provided with a plurality of walls that protrude into the converter-side flow path and cause the cooling liquid to meander. With this configuration, the cooling liquid flowing in the converter-side flow path is caused to meander by the plurality of walls, so that the cooling liquid flowing in the converter-side flow path is made to meander depending on the region in which the converter unit is located, thereby making it possible to more efficiently cool the converter unit.

[0023] In this case, preferably, the converter unit includes a DC / DC converter unit that converts the voltage of the DC power into a different voltage, and a boost converter unit that boosts the DC power input from the DC power supply and supplies it to the inverter unit, and the converter-side flow path includes a first converter flow path provided corresponding to the boost converter unit and a second converter flow path provided corresponding to the DC / DC converter unit. With this configuration, the boost converter unit and the DC / DC converter unit can be individually cooled by the cooling liquid flowing through the first converter flow path and the second converter flow path, respectively, and therefore the boost converter unit and the DC / DC converter unit can be more efficiently cooled.

[0024] In the above-mentioned configuration including the second connection portion, the cooling portion is preferably ,Ko Converter cover that forms the converter side flow path together with the main body Department The second connection flow path has an opening formed on the side where the converter unit is disposed, and the converter lid unit includes a second connection flow path forming portion that covers the opening. With this configuration, the opening of the second connection flow path can be blocked by the second connection flow path forming portion.

[0025] In this case, the second connection flow path forming portion is preferably convex toward the side where the inverter portion is disposed. With this configuration, the depth of the second connection flow path is reduced, so that the pressure loss of the refrigerant can be reduced.

[0027] In this case, preferably, First inverter cover and second inverter cover With this configuration, the heat dissipation area (heat transfer area) in the inverter side flow path is increased, so that the inverter section can be cooled more efficiently. Effect of the Invention

[0029] According to the present invention, as described above, it is possible to provide a power conversion device capable of efficiently cooling an inverter section and a converter section. [Brief description of the drawings]

[0030] [Figure 1] 1 is a diagram showing a circuit configuration of a power conversion device according to an embodiment of the present invention. [Diagram 2] 1 is a schematic diagram showing an entire power conversion device according to an embodiment; [Diagram 3] FIG. 4 is a diagram showing a flow of a cooling liquid outside a power conversion device of an embodiment. [Figure 4] 2 is an exploded perspective view of a base and a lid of a power converter according to one embodiment. FIG. [Diagram 5] 2 is a plan view of a base unit of a power converter according to one embodiment, viewed from the Z2 direction side. FIG. [Figure 6] 2 is a plan view of a base unit of a power converter according to one embodiment, viewed from the Z1 direction side. FIG. [Figure 7] 4 is a cross-sectional view of the base unit, the inverter unit, and the converter unit taken along the X direction (longitudinal direction of the base unit). FIG. [Figure 8] FIG. 8 is a cross-sectional view taken along line 800-800 in FIG. 7. [Figure 9] FIG. 9 is a cross-sectional view taken along line 900-900 in FIG. 8. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

[0032] 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 9. The power conversion device 100 is mounted on a vehicle, for example.

[0033] (Overall configuration of power conversion device) The overall configuration of a power conversion device 100 according to one embodiment of the present invention will be described with reference to FIGS.

[0034] First, a 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 and a converter unit 20.

[0035] The inverter unit 10 converts the DC power transformed by the converter unit 20 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.

[0036] The inverter unit 10 includes a first switching element module 10a and a second switching element module 10b that convert DC power into AC power. The first switching element module 10a is used as a drive inverter. The second switching element module 10b is used as a power generation inverter. Each of the first switching element module 10a and the second switching element module 10b includes semiconductor switching elements Q1, Q2, and Q3 that constitute an upper arm, and semiconductor switching elements Q4, Q5, and Q6 that constitute a lower arm.

[0037] The load 210 includes a first load 210a and a second load 210b. The first switching element module 10a converts DC power input from the DC power supply 200 into AC power and supplies it to the first load 210a. The second switching element module 10b converts DC power input from the DC power supply 200 into AC power and supplies it to the second load 210b.

[0038] The converter unit 20 transforms DC power input from the DC power supply 200. The converter unit 20 includes a boost converter unit 21 and a DCDC converter unit 22. The DCDC converter unit 22 is an example of the "DC-DC converter unit" in the claims.

[0039] The boost converter unit 21 is disposed on the input side of the inverter unit 10. The boost converter unit 21 boosts the DC power input from the DC power source 200 and supplies the boosted power to the inverter unit 10. The boost converter unit 21 includes a boost switching element module 21a and a reactor 21b. The boost switching element module 21a 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 21 also includes a capacitor C1. The reactor 21b is provided between the positive side of the DC power source 200 and a connection point between the boost switching element Q11 and the boost switching element Q12. The capacitor C1 is provided in parallel with the boost switching element Q12.

[0040] At least one of the semiconductor switching elements Q1, Q2, Q3, Q4, Q5, and Q6 and the boost switching elements Q11 and Q12 may be a wide band gap semiconductor element. A wide band gap semiconductor element is a semiconductor element having a larger band gap than a silicon semiconductor element, and is, for example, a semiconductor element including SiC, GaN, diamond, a gallium nitride material, a gallium oxide material, AlN, AlGaN, or ZnO. By using a wide band gap semiconductor element for any of the semiconductor switching elements Q1 to Q6 and the boost switching elements Q11 and Q12, it is possible to improve the switching speed compared to the case of using a silicon semiconductor element.

[0041] The power conversion device 100 also includes a capacitor C2 and a resistor R. The capacitor C2 and the resistor R are provided between the boost converter unit 21 and the inverter unit 10. The capacitor C2 and the resistor R are provided in parallel with each other.

[0042] The DCDC converter unit 22 converts the voltage of the DC power into a different voltage. Specifically, the DCDC converter unit 22 steps down the voltage of the DC power input from the DC power source 200 via the connector 1. The DCDC converter unit 22 also supplies the stepped-down voltage to the output terminal 2.

[0043] Next, the structure of the power conversion device 100 will be described.

[0044] 2, the power conversion device 100 includes a cooling unit 30 disposed between the inverter unit 10 and the converter unit 20. That is, the first switching element module 10a and the second switching element module 10b constituting the inverter unit 10, the boost converter unit 21 and the DCDC converter unit 22 are disposed so as to sandwich the cooling unit 30. The cooling unit 30 is flat plate-shaped.

[0045] In this specification, the direction in which the inverter unit 10 and the cooling unit 30 face each other is defined as the Z direction. One side and the other side in the Z direction are defined as the Z1 direction and the Z2 direction, respectively. The cooling unit 30 has a rectangular shape when viewed from the Z1 direction side or the Z2 direction side. The longitudinal direction of the cooling unit 30 when viewed from the Z1 direction side or the Z2 direction side is defined as the X direction. One side and the other side in the X direction are defined as the X1 direction and the X2 direction, respectively. The direction perpendicular to both the X direction and the Z direction (the short-side direction of the cooling unit 30) is defined as the Y direction. One side and the other side in the Y direction are defined as the Y1 direction and the Y2 direction, respectively. The X direction and the Z direction are examples of the "longitudinal direction" and the "facing direction" in the claims, respectively.

[0046] The first switching element module 10a and the second switching element module 10b are arranged on the Z1 direction side of the flat cooling section 30. The first switching element module 10a and the second switching element module 10b are arranged adjacent to each other along the longitudinal direction (X direction) of the cooling section 30. A capacitor module 40 including a capacitor C2 is arranged on the Z1 direction side of the cooling section 30 and on the Y1 direction side of the inverter section 10.

[0047] The boost converter unit 21 and the DCDC converter unit 22 are disposed on the Z2 direction side of the flat cooling unit 30. The boost converter unit 21 is disposed adjacent to the DCDC converter unit 22 in the X direction. The boost converter unit 21 is disposed on the X2 direction side of the DCDC converter unit 22.

[0048] The DCDC converter unit 22 includes a DC-DC converter element E and a converter board B. The DC-DC converter element E includes a converter switching element 22a, a transformer 22b, a resonant reactor 22c, a smoothing reactor 22d, and a diode element 22e. The power conversion device 100 is configured to convert the voltage of the DC power input from the DC power source 200 into a different voltage by the DC-DC converter element E included in the DCDC converter unit 22. The DC-DC converter element E is mounted on the converter board B. The converter board B has a flat plate shape. The converter board B is a printed circuit board (PCB) on which the DC-DC converter element E is mounted. The converter board B is disposed to face the cooling unit 30.

[0049] (Configuration of Cooling Channel) The cooling unit 30 has a cooling flow path 310 therein. In this embodiment, the cooling flow path 310 includes a first inverter flow path 311, a connection flow path 312, a second inverter flow path 313, a connection flow path 314, a first converter flow path 315, a connection flow path 316, and a second converter flow path 317. The connection flow path 312 is an example of a "second connection flow path" in the claims. The connection flow path 314 is an example of a "first connection flow path" in the claims.

[0050] The cooling unit 30 has therein a first inverter flow path 311 and a second inverter flow path 313 as an inverter side flow path 310a provided corresponding to the inverter unit 10. The cooling unit 30 also has therein a first converter flow path 315 and a second converter flow path 317 as a converter side flow path 310b provided corresponding to the converter unit 20.

[0051] The inverter side flow path 310a is provided on the inverter unit 10 side (Z1 direction side) of the cooling unit 30. The first inverter flow path 311 is a flow path provided on the Z1 direction side of the cooling unit 30 corresponding to the first switching element module 10a. The second inverter flow path 313 is a flow path provided on the Z1 direction side of the cooling unit 30 corresponding to the second switching element module 10b. The second inverter flow path 313 is disposed downstream of the first inverter flow path 311. The first inverter flow path 311 is connected to the second inverter flow path 313 via a connection flow path 312.

[0052] The inverter unit 10 disposed on the Z1 direction side of the cooling unit 30 is cooled by the cooling liquid flowing through the inverter side flow path 310a. Specifically, the first switching element module 10a constituting the inverter unit 10 is cooled by the cooling liquid flowing through the first inverter flow path 311. Moreover, the second switching element module 10b constituting the inverter unit 10 is cooled by the cooling liquid flowing through the second inverter flow path 313.

[0053] Further, the converter side flow path 310b is provided on the converter unit 20 side (Z2 direction side) of the cooling unit 30. The first converter flow path 315 is a flow path provided on the Z2 direction side of the cooling unit 30 corresponding to the boost converter unit 21. The second converter flow path 317 is a flow path provided on the Z2 direction side of the cooling unit 30 corresponding to the DC-DC converter unit 22. The second converter flow path 317 is disposed downstream of the first converter flow path 315. The first converter flow path 315 is connected to the second converter flow path 317 via a connection flow path 316.

[0054] The converter section 20 (boost converter section 21 and DCDC converter section 22) disposed on the Z2 direction side of the cooling section 30 is cooled by the cooling liquid flowing through the converter side flow path 310b. Specifically, the boost switching element module 21a and the reactor 21b constituting the boost converter section 21 are cooled by the cooling liquid flowing through the first converter flow path 315. The DC-DC converter element E constituting the DCDC converter section 22 is cooled by the cooling liquid flowing through the second converter flow path 317. That is, the converter switching element 22a, the transformer 22b, the resonant reactor 22c, the diode element 22e, and the smoothing reactor 22d are cooled by the cooling liquid flowing through the second converter flow path 317.

[0055] In the cooling flow path 310, the inverter side flow path 310a and the converter side flow path 310b are connected so that the cooling liquid passes through the entire inverter side flow path 310a and then passes through the converter side flow path 310b. As a result, the first switching element module 10a and the second switching element module 10b are cooled by the cooling liquid flowing through the inverter side flow path 310a, and then the boost switching element module 21a, the reactor 21b, and the DC-DC converter element E are cooled by the cooling liquid flowing through the converter side flow path 310b.

[0056] In this embodiment, within the cooling unit 30, the inverter side flow path 310a and the converter side flow path 310b are connected by a single connection flow path 314. The connection flow path 314 is disposed on one end side (X1 direction side) in the X direction in which the cooling unit 30 extends.

[0057] The cooling unit 30 also has an inlet I through which the cooling liquid flows in, and an outlet O through which the cooling liquid flows out. The inlet I and the outlet O are both provided on the other end side (X2 direction side) of the cooling unit 30 in the X direction.

[0058] The cooling flow path 310 is connected in this order with an inlet I, an inverter side flow path 310a, a connection flow path 314, a converter side flow path 310b, and an outlet O. More specifically, the cooling flow path 310 is connected in this order with an inlet I, a first inverter flow path 311, a connection flow path 312, a second inverter flow path 313, a connection flow path 314, a first converter flow path 315, a connection flow path 316, a second converter flow path 317, and an outlet O. The cooling flow path 310 is formed so as to turn back at the connection flow path 314 arranged at one end side in the X direction (X1 direction side).

[0059] The cooling liquid flows into the first inverter flow path 311 from an inlet I provided on the X2 direction side of the cooling unit 30, flows through the first inverter flow path 311, the connection flow path 312, the second inverter flow path 313, the connection flow path 314, the first converter flow path 315, the connection flow path 316, and the second converter flow path 317 in this order, and then flows out from an outlet O provided on the X2 direction side of the cooling unit 30. Since the power conversion device 100 has the inverter side flow path 310a and the converter side flow path 310b provided in the single cooling unit 30, the device configuration can be made more compact than when the inverter unit 10 and the converter unit 20 are arranged in separate cooling units and cooled by cooling flow paths provided in each cooling unit.

[0060] 3, the cooling liquid flowing out of the cooling flow passage 310 of the cooling unit 30 is cooled by dissipating heat by the heat dissipation unit 101 outside the power conversion device 100. The cooling liquid cooled by the heat dissipation unit 101 is pumped by a pump 102 outside the power conversion device 100 and flows again into the cooling flow passage 310 of the cooling unit 30. The heat dissipation unit 101 includes a heat exchanger and is cooled by external air. The heat dissipation unit 101 is, for example, a radiator. Note that the pump 102 may be disposed between the outlet O and the heat dissipation unit 101, and the cooling liquid before dissipating heat by the heat dissipation unit 101 may be pumped by the pump 102. The cooling liquid is, for example, liquid such as water or antifreeze.

[0061] As shown in FIG. 4, the cooling unit 30 includes a base unit 31, a lid unit 32, and a lid unit 33. An inverter side flow path 310a (see FIG. 4) and a converter side flow path 310b (see FIG. 5) are formed in the base unit 31. The base unit 31 is an example of a "main body" in the claims. The lid units 32 and 33 are examples of an "inverter lid" and a "converter lid" in the claims, respectively. The base unit 31 may be formed integrally with a housing in which the power conversion device 100 is housed.

[0062] Lid portion 32 (see FIG. 4) is a flat plate-shaped member to which inverter portion 10 is attached. Lid portion 32 forms inverter-side flow path 310a together with base portion 31. Lid portion 32 includes lid portion 32a and lid portion 32b. Lid portion 32a is provided corresponding to first switching element module 10a. Lid portion 32b is provided corresponding to second switching element module 10b. Lid portion 32a and lid portion 32b are examples of a "first inverter lid portion" and a "second inverter lid portion" in the claims, respectively.

[0063] The lid 32a is attached to the base 31 side (Z2 direction side) of the first switching element module 10a. The lid 32a is attached to the Z1 direction side of the base 31 so as to cover the opening A1 provided in the base 31. As a result, the lid 32a forms a first inverter flow path 311 of the inverter side flow path 310a together with the base 31. The lid 32b is attached to the base 31 side (Z2 direction side) of the second switching element module 10b. The lid 32b is attached to the Z1 direction side of the base 31 so as to cover the opening A2 provided in the base 31. As a result, the lid 32b forms a second inverter flow path 313 of the inverter side flow path 310a together with the base 31. The first switching element module 10a and the second switching element module 10b are integrally provided with the lids 32a and 32b, respectively. The first switching element module 10a and the second switching element module 10b may be provided separately from the lids 32a and 32b, respectively.

[0064] The lid portion 33 is a flat plate-shaped member attached to the converter unit 20. The lid portion 33 includes a lid portion 33a and a lid portion 33b. The lid portion 33a is provided corresponding to the boost converter unit 21. The lid portion 33b is provided corresponding to the DC-DC converter unit 22.

[0065] The lid portion 33a is attached to the base portion 31 side (Z1 direction side) of the boost converter portion 21. The lid portion 33a includes a flat base portion F1. The base portion F1 is provided with a plurality of walls F2 and a plurality of pillar portions F3. The plurality of walls F2 are formed so as to extend from the base portion F1 toward the Z1 direction side. The plurality of walls F2 are formed so as to meander when viewed from the Z1 direction side. The plurality of pillar portions F3 are formed so as to protrude in a columnar shape from the base portion F1 toward the Z1 direction side. The base portion F1 may be provided with fins instead of the pillar portions F3.

[0066] The lid portion 33b is attached to the base portion 31 side (Z1 direction side) of the DC-DC converter portion 22. The lid portion 33b includes a flat base portion H1. The base portion H1 is provided with a plurality of walls H2 and pillar portions F3. The plurality of walls H2 are formed so as to extend from the base portion H1 in the Z1 direction. The plurality of walls H2 are formed so as to meander when viewed from the Z1 direction side.

[0067] The base 31 and the lids 32a, 32b, 33a, and 33b are members made of metal. The base 31 and the lids 32a, 32b, 33a, and 33b are formed of a metal having relatively high thermal conductivity, such as aluminum. The lids 32a, 32b, 33a, and 33b are attached to the base 31 by screws (not shown).

[0068] The lid portion 33 forms a converter-side flow path 310b (see FIG. 5) together with the base portion 31. The lid portion 33a is attached to the Z2 direction side of the base portion 31 so as to cover an opening A3 provided in the base portion 31. As a result, the lid portion 33a forms a first converter flow path 315 of the converter-side flow path 310b together with the base portion 31. The lid portion 33b is attached to the Z2 direction side of the base portion 31 so as to cover an opening A4 provided in the base portion 31. As a result, the lid portion 33b forms a second converter flow path 317 of the converter-side flow path 310b together with the base portion 31.

[0069] The lid 33b is attached to the Z2 side of the base 31 so as to cover the opening A5 provided in the base 31. As a result, the lid 33b forms the connection flow path 312 together with the base 31. The portion 33c (see FIG. 7) of the lid 33b that covers the opening A5 is an example of the "second connection flow path forming portion" in the claims. In this embodiment, the first converter flow path 315, the connection flow path 316, the second converter flow path 317, and the outlet O are arranged in this order from the X1 direction side. The connection flow path 312 is arranged to be sandwiched between the first converter flow path 315 and the second converter flow path 317 when viewed from the Z2 direction side. The opening A5 may be covered by the lid 33a. In this case, the lid 33a forms the connection flow path 312 together with the base 31. The lid 33b or 33a may be provided with a protrusion that is inserted into the opening A5. This reduces the depth of the connection flow passage 12 in the Z direction, thereby reducing the pressure loss of the refrigerant. The protrusion inserted into the opening A5 is an example of a "second connection flow passage forming portion" in the claims.

[0070] The converter-side flow passage 310b is formed so that the flow of the cooling liquid meanders when viewed from the Z2 direction side. Moreover, the cooling flow passage 310 is formed so that the cooling liquid branches into a plurality of flow passages inside the converter-side flow passage 310b.

[0071] The multiple walls F2 protrude into the converter-side flow path 310b and cause the cooling liquid to meander. The cooling liquid that flows from the connection flow path 314 to the first converter flow path 315 is branched into multiple flow paths by the multiple walls F2 and meanders in a U-shape. The cooling liquid that has been branched into multiple flow paths by the multiple walls F2 joins together in the connection flow path 316.

[0072] The multiple walls H2 protrude into the converter-side flow path 310b and cause the cooling liquid to meander. The cooling liquid that flows from the connection flow path 316 into the second converter flow path 317 is branched into multiple flow paths by the multiple walls H2 and meanders in a U-shape. The cooling liquid that has been branched into multiple flow paths by the multiple walls H2 joins together just before the outlet O.

[0073] 6, the inverter-side flow path 310a is formed linearly along the X direction (longitudinal direction) when viewed from the Z1 direction side. As described above, the linear inverter-side flow path 310a is formed by the base part 31 and the lid part 32.

[0074] The first inverter flow path 311 and the second inverter flow path 313 are linearly arranged along the X direction (longitudinal direction) and are connected to each other. Specifically, the first inverter flow path 311 and the second inverter flow path 313 are connected to each other via a connection flow path 312. In this embodiment, from the X2 direction side, the inlet I, the first inverter flow path 311, the connection flow path 312, the second inverter flow path 313, and the connection flow path 314 are arranged in this order. Moreover, the inlet I is arranged on the Y2 direction side of the outlet O.

[0075] Further, the inverter side flow path 310a is provided with a plurality of convex parts G for adjusting the flow of the cooling liquid. The plurality of convex parts G are provided in the second inverter flow path 313 arranged downstream of the first inverter flow path 311. As shown in FIG. 7, the plurality of convex parts G protrude toward the inside of the inverter side flow path 310a (the second inverter flow path 313). The plurality of convex parts G have a hemispherical shape (a dome shape). In this embodiment, the cooling unit 30 uses the plurality of convex parts G to increase the flow rate of the cooling liquid flowing in the second inverter flow path 313 and to make the cooling liquid flowing in the second inverter flow path 313 into a turbulent state. This allows the second switching element module 10b to be efficiently cooled by the cooling liquid flowing in the second inverter flow path 313. In this embodiment, the plurality of protrusions G are provided in the inverter side flow path 310a (second inverter flow path 313) corresponding to the second switching element module 10b, but may be provided in the inverter side flow path 310a (first inverter flow path 311) corresponding to the first switching element module 10a. Or, they may be provided in the inverter side flow paths 310a corresponding to both the first switching element module 10a and the second switching element module 10b. In this embodiment, it is assumed that the second switching element module 10b generates more heat than the first switching element module 10a. In addition, the cover portion 32a and the cover portion 32b in this embodiment are not provided with fins, but at least one of them may be provided with fins to improve cooling performance.

[0076] As shown in FIG. 7, the cooling passage 310 is formed such that an inverter side passage 310a and a converter side passage 310b overlap each other when viewed from the Z1 direction side or the Z2 direction side.

[0077] The connection flow path 312 connecting the first inverter flow path 311 and the second inverter flow path 313 has a U-shape that is curved on the Z2 direction side where the converter unit 20 is disposed. As described above, the connection flow path 312 is formed by the base unit 31 and the lid unit 33b.

[0078] In this embodiment, the second inverter flow path 313 has a flow path depth smaller than that of the first inverter flow path 311. Specifically, as shown in Fig. 7, the second inverter flow path 313 is formed such that a flow path depth D2 in the Z direction of the second inverter flow path 313 is smaller (shallower) than a flow path depth D1 in the Z direction of the first inverter flow path 311.

[0079] The connection flow path 314 is formed to extend in the Z direction so as to connect the second inverter flow path 313 provided on the Z1 direction side and the first converter flow path 315 provided on the Z2 direction side.

[0080] Furthermore, frame-shaped packings P1, P2, P3, and P4 for preventing leakage of the cooling liquid are fitted into the base portion 31. The packings P1, P2, P3, and P4 are pressed against the base portion 31 by the lid portions 32a, 32b, 33a, and 33b, respectively.

[0081] Furthermore, reactor 21b is attached to the Z2 direction side of lid portion 33a. Thermally conductive grease (heat dissipating grease) is applied between lid portion 33a and reactor 21b.

[0082] As shown in FIG. 8, the connection flow path 314 is formed by the base portion 31, the lid portion 32b, and the lid portion 33a. The pillar portion F3 of the lid portion 33a is disposed on the Y1 direction side of the convex portion G of the base portion 31. The pillar portion F3 of the lid portion 33a is disposed at a position overlapping the boost switching element module 21a when viewed from the Z1 direction side or the Z2 direction side. In this embodiment, the heat dissipation area (heat transfer area) in the first converter flow path 315 is increased by the plurality of pillar portions F3, so that the boost switching element module 21a can be cooled more efficiently. The boost switching element module 21a is attached to the Z2 direction side of the lid portion 33a. Heat conductive grease (heat dissipation grease) is applied between the lid portion 33a and the boost switching element module 21a. The boost switching element module 21a is disposed on the Y1 direction side of the reactor 21b. Each of the boost switching element module 21a and the reactor 21b may be attached so as to be in direct contact with the lid portion 33a.

[0083] 9, the connection flow path 316 is disposed between the first converter flow path 315 and the second converter flow path 317 in the X direction. The connection flow path 316 has a U-shape that curves toward the Z1 direction side where the converter unit 20 is disposed. The connection flow path 316 is formed so as to straddle the lid portion 33a and the lid portion 33b in the X direction.

[0084] (Effects of this embodiment) In this embodiment, the following effects can be obtained.

[0085] In this embodiment, the cooling unit 30 disposed between the inverter unit 10 and the converter unit 20 has a cooling flow path 310 therein, which includes an inverter side flow path 310a and a converter side flow path 310b connected to the inverter side flow path 310a. This allows the inverter unit 10 and the converter unit 20 to be individually cooled by sequentially flowing the cooling liquid through the inverter side flow path 310a and the converter side flow path 310b. As a result, it is possible to suppress the occurrence of a temperature difference in the cooling liquid flowing through the same flow path, and therefore it is possible to suppress the occurrence of unintended convection of the cooling liquid caused by the temperature difference. This allows the inverter unit 10 and the converter unit 20 to be efficiently cooled by the cooling liquid flowing through the cooling flow path 310. Furthermore, since the cooling flow path 310 is connected between the inverter side flow path 310a and the converter side flow path 310b such that the cooling liquid passes through the entire inverter side flow path 310a and then through the converter side flow path 310b, the inverter unit 10 can be cooled more efficiently than when the cooling liquid passes through the converter side flow path 310b and then through the inverter side flow path 310a.

[0086] In the present embodiment, as described above, the cooling flow path 310 is disposed at one end side (X1 direction side) in the longitudinal direction of the cooling unit 30, and includes a connection flow path 314 that connects the inverter side flow path 310a and the converter side flow path 310b in the cooling unit 30. As a result, the inverter side flow path 310a and the converter side flow path 310b are connected by the connection flow path 314 in the cooling unit 30, so that the cooling flow path 310 can be formed so that the cooling liquid flows sequentially. As a result, unlike the case where the inverter side flow path 310a and the converter side flow path 310b are connected outside the cooling unit 30, the configuration of the cooling unit 30 can be simplified. In addition, since the inverter side flow path 310a and the converter side flow path 310b are connected by a single connection flow path 314, the configuration of the cooling unit 30 can be simplified more than the case where the inverter side flow path 310a and the converter side flow path 310b are connected by a plurality of flow paths.

[0087] In the present embodiment, as described above, the cooling unit 30 has an inlet I through which the cooling liquid flows in and an outlet O through which the cooling liquid flows out. The cooling flow path 310 is formed by connecting the inlet I, the inverter side flow path 310a, the connection flow path 314, the converter side flow path 310b, and the outlet O in this order, and turning back at the connection flow path 314 disposed at one end side (X1 direction side) in the longitudinal direction. This makes it possible to suppress an increase in the size of the cooling unit 30 in the X direction (longitudinal direction) compared to a case in which the inlet I, the inverter side flow path 310a, the connection flow path 314, the converter side flow path 310b, and the outlet O are linearly connected along the X direction (longitudinal direction). Also, the configuration of the cooling unit 30 can be simplified compared to a case in which the inverter side flow path 310a and the converter side flow path 310b are alternately connected.

[0088] In addition, in this embodiment, as described above, the cooling flow path 310 is formed such that the inverter side flow path 310a and the converter side flow path 310b overlap each other when viewed from the Z1 direction or the Z2 direction. This makes it possible to suppress an increase in the size of the cooling unit 30 in the X direction or the Y direction, compared to a case in which the cooling flow path 310 is formed such that the inverter side flow path 310a and the converter side flow path 310b do not overlap when viewed from the Z1 direction or the Z2 direction.

[0089] In addition, in this embodiment, as described above, the inverter side flow path 310a is formed linearly along the X direction (longitudinal direction of the cooling unit 30) when viewed from the Z1 direction side, and the converter side flow path 310b is formed so that the flow of the cooling liquid meanders when viewed from the Z2 direction side. As a result, since the inverter side flow path 310a is formed linearly along the X direction (longitudinal direction of the cooling unit 30), it is possible to suppress the inverter side flow path 310a from becoming complicated and to simplify the configuration of the cooling unit 30. Furthermore, since the converter side flow path 310b is formed so that the flow of the cooling liquid meanders, the converter unit 20 can be cooled more efficiently by making the flow of the cooling liquid in the converter side flow path 310b meander depending on the region where the converter unit 20 is arranged.

[0090] In this embodiment, as described above, the cooling flow path 310 is formed so as to branch the cooling liquid into a plurality of flow paths inside the converter side flow path 310b. This allows the cooling liquid flowing through the converter side flow path 310b to be diffused over a wider range. As a result, the cooling liquid can be distributed evenly throughout the converter side flow path 310b, so that the converter section 20 can be cooled more efficiently.

[0091] In this embodiment, as described above, the inlet I and the outlet O are both provided on the other end side (X2 direction side) in the longitudinal direction of the cooling unit 30. As a result, the pipes connected to the power conversion device 100 for inflowing or outflowing the cooling liquid are both connected to the X2 direction side (the other end side in the longitudinal direction) of the cooling unit 30, so that an increase in the size of the power conversion device 100 including the pipes in the X direction (longitudinal direction) can be suppressed compared to a case in which the pipes are connected to both the X1 direction side (one end side in the longitudinal direction) and the X2 direction side of the cooling unit 30.

[0092] In this embodiment, as described above, the cooling unit 30 includes the base unit 31 in which the inverter-side flow path 310a and the converter-side flow path 310b are formed, and the flat lid unit 32 to which the inverter unit 10 is attached and which, together with the base unit 31, forms the inverter-side flow path 310a that is linear when viewed from the Z1 direction side. This allows the lid unit 32 to which the inverter unit 10 is attached to be in direct contact with the cooling liquid flowing through the inverter-side flow path 310a, so that heat generated by the inverter unit 10 can be efficiently dissipated via the lid unit 32.

[0093] In addition, in this embodiment, as described above, the inverter side flow path 310a is provided with a plurality of convex parts G that protrude into the inverter side flow path 310a and adjust the flow of the cooling liquid. As a result, the flow of the cooling liquid can be adjusted by the plurality of convex parts G protruding into the inverter side flow path 310a (inside the cooling flow path 310) to increase the flow rate of the cooling liquid flowing in the inverter side flow path 310a. As a result, the inverter unit 10 can be cooled efficiently. In addition, the plurality of convex parts G increase the heat dissipation area (heat transfer area) in the inverter side flow path 310a, so that the inverter unit 10 can be cooled more efficiently.

[0094] In the present embodiment, as described above, the inverter unit 10 includes the first switching element module 10a and the second switching element module 10b that convert DC power into AC power. The inverter side flow path 310a includes a first inverter flow path 311 provided in correspondence with the first switching element module 10a and a second inverter flow path 313 provided in correspondence with the second switching element module 10b. Furthermore, the first inverter flow path 311 and the second inverter flow path 313 arranged in a straight line along the X direction (longitudinal direction) are connected to each other. This allows the first switching element module 10a and the second switching element module 10b to be individually cooled by the cooling liquid flowing through each of the first inverter flow path 311 and the second inverter flow path 313. As a result, the first switching element module 10a and the second switching element module 10b can be cooled more efficiently than when the first switching element module 10a and the second switching element module 10b are both cooled by the cooling liquid flowing through the same flow path.

[0095] In the present embodiment, as described above, the cooling flow path 310 has a U-shape that curves on the side (Z2 direction side) where the converter unit 20 is disposed, and includes the connection flow path 312 that connects the first inverter flow path 311 and the second inverter flow path 313. The U-shaped connection flow path 312 can connect the first inverter flow path 311 and the second inverter flow path 313 so as to detour to the side where the converter unit 20 is disposed. As a result, the first inverter flow path 311 and the second inverter flow path 313 can be more easily connected depending on the arrangement and shape of the first inverter flow path 311 and the second inverter flow path 313, compared to the case where the first inverter flow path 311 and the second inverter flow path 313 are connected by a linear flow path.

[0096] In addition, in this embodiment, as described above, the second inverter flow path 313 is disposed downstream of the first inverter flow path 311, and the second inverter flow path 313 is provided with a plurality of convex parts G that protrude into the second inverter flow path 313 and adjust the flow of the cooling liquid. With this, the flow of the cooling liquid flowing in the second inverter flow path 313 can be adjusted by the plurality of convex parts G protruding into the second inverter flow path 313, and the flow rate of the cooling liquid flowing in the second inverter flow path 313 can be increased. As a result, the second switching element module 10b can be cooled efficiently. In addition, compared to the case where a plurality of convex parts G are provided in both the first inverter flow path 311 and the second inverter flow path 313, it is possible to suppress the structure of the inverter side flow path 310a in the cooling unit 30 from becoming complicated and the weight of the cooling unit 30 from increasing due to the increase in the number of convex parts G. In addition, the plurality of convex parts G increases the heat dissipation area (heat transfer area) in the second inverter flow path 313, so that the second switching element module 10b can be cooled more efficiently.

[0097] In addition, in this embodiment, as described above, the second inverter flow path 313 is disposed downstream of the first inverter flow path 311, and the second inverter flow path 313 has a flow path depth D2 smaller than that of the first inverter flow path 311. This allows the cross-sectional area of ​​the second inverter flow path 313 to be smaller than that of the first inverter flow path 311, so that the flow rate of the cooling liquid flowing through the second inverter flow path 313 can be made faster than the flow rate of the cooling liquid flowing through the first inverter flow path 311. As a result, the second switching element module 10b can be cooled more efficiently by the second inverter flow path 313 than the first switching element module 10a is cooled by the first inverter flow path 311. This allows the second switching element module 10b to be sufficiently cooled even when the second switching element module 10b generates more heat than the first switching element module 10a.

[0098] In this embodiment, as described above, the cooling unit 30 includes the lid portion 33 that, together with the base portion 31, forms the converter-side flow path 310b that meanders when viewed from the Z2 direction side. The converter unit 20 is attached to the lid portion 33. The lid portion 33 is further provided with a plurality of walls F2 and H2 that protrude into the converter-side flow path 310b and cause the cooling liquid to meander. As a result, the cooling liquid flowing in the converter-side flow path 310b is caused to meander by the plurality of walls F2 and H2, and the cooling liquid flowing in the converter-side flow path 310b is caused to meander depending on the region in which the converter unit 20 is arranged, thereby making it possible to more efficiently cool the converter unit 20.

[0099] In the present embodiment, as described above, the converter unit 20 includes the DCDC converter unit 22 that converts the voltage of the DC power into a different voltage, and the boost converter unit 21 that boosts the DC power input from the DC power source 200 and supplies it to the inverter unit 10. The converter side flow path 310b includes a first converter flow path 315 provided corresponding to the boost converter unit 21, and a second converter flow path 317 provided corresponding to the DCDC converter unit 22. This allows the boost converter unit 21 and the DCDC converter unit 22 to be individually cooled by the cooling liquid flowing through each of the first converter flow path 315 and the second converter flow path 317, so that the boost converter unit 21 and the DCDC converter unit 22 can be cooled more efficiently.

[0100] [Variations] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims rather than the description of the above embodiments, and further includes all modifications (variations) within the meaning and scope of the claims.

[0101] For example, in the above embodiment, the inverter side flow path 310a and the converter side flow path 310b are connected by a single connection flow path 314 (first connection flow path), but the present invention is not limited to this. For example, the inverter side flow path and the converter side flow path may be connected by multiple first connection flow paths.

[0102] In the above embodiment, the cooling flow path 310 is formed so as to be folded back at the connection flow path 314 (first connection flow path) arranged at one end side (X1 direction side) in the X direction (longitudinal direction of the cooling unit 30), but the present invention is not limited to this. In the present invention, the cooling flow path may be formed so as to be folded back in a piping outside the cooling unit. Also, the cooling flow path may be formed so as to be folded back at the center in the longitudinal direction of the cooling unit.

[0103] In the above embodiment, the cooling flow passage 310 is formed such that the inverter side flow passage 310a and the converter side flow passage 310b overlap each other when viewed from the Z1 direction or the Z2 direction (opposing direction), but the present invention is not limited to this. In the present invention, the cooling flow passage may be arranged such that the inverter side flow passage and the converter side flow passage do not overlap each other when viewed from the opposing direction.

[0104] In the above embodiment, the inverter-side flow path 310a is formed linearly along the X direction when viewed from the Z1 direction side (opposing direction), but the present invention is not limited to this. In the present invention, the inverter-side flow path may be formed to meander when viewed from the opposing direction in which the inverter unit and the cooling unit face each other.

[0105] In the above embodiment, the converter side flow path 310b is formed so that the flow of the cooling liquid meanders when viewed from the Z2 direction side (opposing direction), but the present invention is not limited to this. In the present invention, the converter side flow path 310b may be formed so that the flow of the cooling liquid is linear.

[0106] In the above embodiment, the cooling flow path 310 is formed so as to branch the cooling liquid into a plurality of flow paths inside the converter-side flow path 310b, but the present invention is not limited to this. In the present invention, the flow path inside the converter-side flow path may be formed as a single flow path.

[0107] In the above embodiment, the inlet I and the outlet O are both provided on the other end side (X2 direction side) in the X direction (longitudinal direction of the cooling section 30), but the present invention is not limited to this. In the present invention, at least one of the inlet and the outlet may be provided on one end side in the longitudinal direction of the cooling section. Also, at least one of the inlet and the outlet may be provided on one end side or the other end side in the lateral direction of the cooling section. For example, the inlet and the outlet may both be provided on one end side or the other end side in the lateral direction of the cooling section.

[0108] In the above embodiment, the cooling unit 30 includes the base 31 (main body) and the flat lid 32 (inverter lid) that forms the inverter-side flow path 310a together with the base 31, but the present invention is not limited to this. In the present invention, the cooling unit may have the inverter-side flow path formed only by the main body.

[0109] In the above embodiment, the inverter-side flow path 310a is provided with a plurality of protrusions G that protrude into the inverter-side flow path 310a and adjust the flow of the cooling liquid, but the present invention is not limited to this. In the present invention, the inverter-side flow path may be formed to have a flat inner wall surface without providing a plurality of protrusions.

[0110] In the above embodiment, the inverter-side flow path 310a includes the first inverter flow path 311 provided corresponding to the first switching element module 10a and the second inverter flow path 313 provided corresponding to the second switching element module 10b, but the present invention is not limited to this. In the present invention, a common flow path may be provided corresponding to the first switching element module and the second switching element module.

[0111] In the above embodiment, the first inverter flow path 311 and the second inverter flow path 313 are linearly arranged along the X direction (longitudinal direction) and connected to each other, but the present invention is not limited to this. In the present invention, the first inverter flow path and the second inverter flow path may be arranged adjacent to each other in the short-side direction of the cooling unit.

[0112] In the above embodiment, the cooling flow path 310 has a U-shape that curves on the side (Z2 direction side) where the converter unit 20 is arranged, and includes the connection flow path 312 (second connection flow path) that connects the first inverter flow path 311 and the second inverter flow path 313, but the present invention is not limited to this. In the present invention, a linear second connection flow path may connect the first inverter flow path and the second inverter flow path.

[0113] In the above embodiment, the second inverter flow path 313 is provided with a plurality of protrusions G that protrude into the second inverter flow path 313 and adjust the flow of the cooling liquid, but the present invention is not limited to this. In the present invention, a plurality of protrusions may be provided in both the first inverter flow path and the second inverter flow path.

[0114] In the above embodiment, the second inverter flow path 313 has a flow path depth D2 smaller than that of the first inverter flow path 311, but the present invention is not limited to this. In the present invention, the second inverter flow path may have a flow path depth larger than that of the first inverter flow path. Furthermore, the second inverter flow path may have approximately the same flow path depth as the first inverter flow path.

[0115] In the above embodiment, the cooling unit 30 includes the cover 33 that forms the converter-side flow path 310b together with the base 31 (main body), but the present invention is not limited to this. In the present invention, the cooling unit may have the converter-side flow path formed only by the main body.

[0116] In the above embodiment, the converter-side flow path 310b includes the first converter flow path 315 provided corresponding to the boost converter unit 21 and the second converter flow path 317 provided corresponding to the DC-DC converter unit 22 (DC-DC converter unit), but the present invention is not limited to this. In the present invention, a common flow path may be provided for the boost converter unit and the DC-DC converter unit.

[0117] In the above embodiment, the inverter section 10 includes two switching element modules, the first switching element module 10a and the second switching element module 10b, but the present invention is not limited to this. The present invention is also applicable to a configuration in which only one switching element module is provided in the inverter section 10. In this case, there is one inverter-side flow path, and one lid portion covering the inverter-side flow path. In addition, multiple convex portions protruding toward the inverter-side flow path are provided in one inverter-side flow path. [Explanation of symbols]

[0118] 10 Inverter section 10a First switching element module 10b Second switching element module 20 Converter section 21 Boost converter section 30 Cooling section 31 Base part (main body part) 32 Lid (inverter lid) 32a Lid (first inverter lid) 32b Lid (second inverter lid) 33, 33a, 33b Lid (converter lid) 33c portion (second connection flow path forming portion) 100 Power conversion device 200 DC power supply 210 Load 310 Cooling Channel 310a Inverter side flow path 310b Converter side flow path 311 1st inverter flow path 312 Connection flow path (second connection flow path) 313 2nd inverter flow path 314 Connection channel (first connection channel) 315 1st converter flow path 317 Second converter flow path A5 opening D1, D2 Channel depth F2 wall G Convex H2 wall I Inlet O Outlet

Claims

1. A converter unit that transforms DC power input from a DC power source; an inverter unit that converts the DC power transformed by the converter unit into AC power and supplies the AC power to a load, and that includes a first switching element module and a second switching element module that convert the DC power into the AC power; a cooling unit that is disposed between the inverter unit and the converter unit and has an inlet through which a cooling liquid flows and an outlet through which the cooling liquid flows out, the cooling unit has an internal cooling flow path including an inverter-side flow path including a first inverter flow path provided corresponding to the first switching element module and a second inverter flow path provided corresponding to the second switching element module, and a converter-side flow path connected to the inverter-side flow path, and the cooling unit includes a main body portion in which the inverter-side flow path and the converter-side flow path are formed, and a flat first inverter lid portion and a flat second inverter lid portion to which the first switching element module and the second switching element module are attached and which form the first inverter flow path and the second inverter flow path, at least one of the first inverter flow path and the second inverter flow path is provided with a plurality of protrusions that are provided on the main body portion so as to protrude into the inverter-side flow path, protruding toward the inverter portion and for adjusting a flow of the cooling liquid, a cooling flow path including the inlet, the inverter side flow path, the converter side flow path, and the outlet, which are connected in this order, so that the cooling liquid passes through the entire inverter side flow path and then through the converter side flow path.

2. 2. The power conversion device according to claim 1, wherein the cooling flow path is arranged at one end side in a longitudinal direction in which the cooling unit extends, and further includes a first connection flow path that connects the inverter side flow path and the converter side flow path within the cooling unit.

3. A power conversion device as described in claim 2, wherein the cooling flow path is formed so that the inlet, the inverter side flow path, the first connecting flow path, the converter side flow path, and the outlet are connected in this order, and are folded back at the first connecting flow path arranged on the one end side in the longitudinal direction.

4. The power conversion device according to claim 3 , wherein the cooling flow passage is formed such that the inverter side flow passage and the converter side flow passage overlap each other when viewed from a direction in which the inverter unit and the cooling unit face each other.

5. the inverter-side flow path is formed linearly along the longitudinal direction when viewed from a direction in which the inverter unit and the cooling unit face each other, The power conversion device according to claim 3 , wherein the converter-side flow path is formed so that the flow of the cooling liquid meanders when viewed from the opposing direction.

6. The power conversion device according to claim 5 , wherein the cooling flow passage is formed inside the converter side flow passage so as to branch the cooling liquid into a plurality of flow passages.

7. The power conversion device according to claim 3 , wherein the inlet and the outlet are both provided on the other end side in the longitudinal direction of the cooling portion.

8. A power conversion device as described in claim 3, wherein the first inverter flow path and the second inverter flow path arranged in a straight line along the longitudinal direction are connected to each other.

9. The power conversion device according to claim 8 , wherein the cooling flow passage further includes a second connection flow passage that is curved toward a side where the converter unit is arranged and connects the first inverter flow passage and the second inverter flow passage.

10. the second inverter flow path is disposed downstream of the first inverter flow path, The power conversion device according to claim 8 , wherein the plurality of protrusions are provided in the second inverter flow path.

11. The power conversion device according to claim 10 , wherein the plurality of protrusions are provided in the second inverter flow path so as to protrude into the second inverter flow path and adjust a flow of the cooling liquid.

12. the second inverter flow path is disposed downstream of the first inverter flow path, The power converter of claim 8 , wherein the second inverter flow path has a flow path depth less than the first inverter flow path.

13. the cooling unit further includes a converter lid unit that, together with the main body unit, forms the converter-side flow path that meanders when viewed from the opposing direction, the converter unit is attached to the converter lid unit, The power conversion device according to claim 5 , wherein the converter lid portion is provided with a plurality of walls that protrude into the converter side flow path and cause the cooling liquid to meander.

14. the converter unit includes a DC-DC converter unit that converts a voltage of the DC power into a different voltage, and a boost converter unit that boosts the DC power input from the DC power source and supplies the boosted DC power to the inverter unit, The power conversion device according to claim 13 , wherein the converter-side flow path includes a first converter flow path provided corresponding to the boost converter unit, and a second converter flow path provided corresponding to the DC-DC converter unit.

15. the cooling unit further includes a converter lid unit that forms the converter side flow path together with the main body unit, an opening is formed on a side of the second connection flow path where the converter unit is disposed, The power conversion device according to claim 9 , wherein the converter lid portion includes a second connection flow path forming portion that covers the opening portion.

16. The power conversion device according to claim 15 , wherein the second connection-flow-path forming portion includes a convex portion that protrudes toward a side on which the inverter unit is disposed.

17. The power conversion device according to claim 3 , wherein the first inverter lid portion and the second inverter lid portion are formed with fins.

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