Power conversion device and motor unit

Abstract

A power conversion device comprising a capacitor and a motor unit, which contribute to suppressing the influence of heat transferred from an electrical component connected to the capacitor on the operation of the capacitor. The capacitor has a plurality of surfaces, a plurality of cooling plates, and a cooling flow path section.

Description

Technical area

[0001] The present invention relates to a power conversion device with a capacitor and a motor unit with such a power conversion device. State of the art

[0002] Previously, a capacitor comprising a capacitor element unit and a housing has been known. The capacitor element unit has a bus, and the housing accommodates the capacitor element unit such that a terminal portion of the bus protrudes. A metal plate for cooling is provided on one side surface of the housing by insert molding (see, for example, Patent Document 1).

[0003] Patent document 1: WO 2021 / 014 927 A1

[0004] In the above capacitor, by providing the metal plate, an influence of heat generated by the capacitor on an operation of the capacitor can be suppressed.

[0005] However, in practical applications, heat from a power module or other electrical component electrically connected to the terminal section of the bus is also transferred to the capacitor via the bus. This could lead to overheating of the capacitor due to the heat transferred from the electrical component, preventing normal operation.

[0006] The document DE 10 2018 203 362 A1 relates to a cooling device for cooling a power component as well as to an electronic arrangement with such a cooling device and a power component and to a control unit of a vehicle. Disclosure of the invention

[0007] In view of the above problem, the present invention has for its object to provide a power conversion device having a capacitor and a motor unit having such a power conversion device, which contribute to suppressing an influence of heat transferred from an electrical component connected to the capacitor on an operation of the capacitor.

[0008] According to the invention, the object is achieved by a power conversion device with a capacitor having a first surface and a second surface which intersect, and a bus, wherein the bus comprises a first bus which has a first extension section which extends along the second surface, wherein a side of the first bus opposite the first surface serves for electrical connection to a first electrical component, wherein a first cooling plate is provided on the first surface and a second cooling plate is provided on the second surface such that the first extension section is at least partially covered.

[0009] The bus comprises the first bus, which has the first extension section extending along the second surface. The side of the first bus opposite the first surface serves for electrical connection to the first electrical component. The first cooling plate is provided on the first surface, and the second cooling plate is provided on the second surface such that the first extension section is at least partially covered.Thus, in addition to dissipating the heat generated by the capacitor using the first cooling plate on the first surface side, the heat transferred from the first electrical component to the capacitor via the first bus can be further dissipated by means of the second cooling plate on the second surface side, and furthermore, the capacitor can be cooled from two directions, thereby suppressing the influence of the heat transferred from the first electrical component on an operation of the capacitor.

[0010] The capacitor further comprises a third surface intersecting the first surface and different from the second surface, wherein the bus comprises a second bus having a second extension portion extending along the third surface, wherein a side of the second bus opposite the first surface serves for electrical connection to a second electrical component, wherein a third cooling plate is provided on the third surface such that the second extension portion is at least partially covered.

[0011] The capacitor further has the third surface that intersects the first surface and is different from the second surface. The bus includes the second bus having the second extension portion extending along the third surface. The side of the second bus opposite the first surface is for electrical connection to the second electrical component. The third cooling plate is provided on the third surface such that the second extension portion is at least partially covered. Thus, further, the heat transferred from the second electrical component to the capacitor via the second bus can be dissipated by means of the third cooling plate on the third surface side, and thereby the capacitor can be cooled from three directions, thereby suppressing the influence of the heat transferred from the second electrical component on an operation of the capacitor.

[0012] The power conversion device includes a first power module as the first electrical component and a second power module as the second electrical component.

[0013] Furthermore, the power conversion device according to the invention is provided to further comprise a cooling flow path section to which the heat originating from the second cooling plate and the third cooling plate is dissipated via the first cooling plate.

[0014] The power conversion device according to the invention further comprises the cooling flow path section, to which the heat originating from the second cooling plate and the third cooling plate is dissipated via the first cooling plate. Thus, the cooling flow path section can achieve better dissipation of the heat generated by the capacitor and the heat transferred from the first electrical component and the second electrical component.

[0015] Furthermore, in the power conversion device according to the invention, it is provided that the capacitor further has a fourth surface which is connected to the first surface, the second surface and the third surface, wherein a cooling component is provided between the fourth surface and the cooling flow path section, which cooling component releases the heat originating from the fourth surface to the cooling flow path section.

[0016] In the power conversion device according to the invention, the capacitor further comprises the fourth surface, which is connected to the first surface, the second surface, and the third surface. The cooling component is provided between the fourth surface and the cooling flow path section, which transfers the heat originating from the fourth surface to the cooling flow path section. Thus, the cooling flow path section can achieve better dissipation of the heat generated by the capacitor and the heat transferred from the first electrical component and the second electrical component.

[0017] Furthermore, in the power conversion device according to the invention, it is provided that the capacitor further has a fifth surface, wherein the fifth surface and the first surface are aligned in opposite directions, wherein the fifth surface is connected to the second surface, the third surface and the fourth surface, wherein the first power module and the second power module are located between the fifth surface and the cooling flow path section and the side of the first power module and the second power module which are opposite to the fifth surface are in direct or indirect contact with the cooling flow path section.

[0018] In the power conversion device according to the invention, the capacitor further has a fifth surface, and the fifth surface and the first surface are oriented in opposite directions. The fifth surface is connected to the second surface, the third surface, and the fourth surface. The first power module and the second power module are located between the fifth surface and the cooling flow path section. The first power module and the second power module are in direct or indirect contact with the cooling flow path section on the side opposite the fifth surface. Thus, by means of the cooling flow path section, better dissipation of the heat generated by the capacitor and the heat transferred from the first electrical component and the second electrical component can be achieved.

[0019] Furthermore, it is preferably provided that the second surface and the third surface are aligned in opposite directions.

[0020] Furthermore, it is preferably provided that the bus comprises a connecting portion which extends along the first surface and connects the first bus to the second bus, wherein the first cooling plate at least partially covers the connecting portion.

[0021] The bus includes the connecting portion extending along the first surface and connecting the first bus to the second bus, and the first cooling plate at least partially covers the connecting portion. Thus, the heat generated by the capacitor can be easily transferred to the first cooling plate for cooling via the connecting portion, further suppressing the influence of the heat generated by the capacitor on the operation of the capacitor.

[0022] Furthermore, it is preferably provided that the first cooling plate, the second cooling plate and the third cooling plate are each a metal plate and an insulating layer is provided between the connecting section and the first cooling plate, between the first bus and the second cooling plate and between the second bus and the third cooling plate.

[0023] Furthermore, it is preferably provided that the capacitor has a resin casing and a capacitor element embedded in the casing, wherein the first extension portion and the second extension portion are embedded near the surface of the casing and the first cooling plate, the second cooling plate and the third cooling plate are in contact with the surface of the casing.

[0024] The capacitor includes a resin casing and a capacitor element embedded in the casing. The first extension portion and the second extension portion are embedded near the surface of the casing, and the first cooling plate, the second cooling plate, and the third cooling plate are in contact with the surface of the casing. Thus, the heat generated by the capacitor and the heat transferred from the first electrical component and the second electrical component can be better dissipated by the first cooling plate, the second cooling plate, and the third cooling plate.

[0025] Furthermore, it is preferably provided that the second cooling plate and the third cooling plate are each connected to the first cooling plate.

[0026] The second cooling plate and the third cooling plate are each connected to the first cooling plate. This allows the cooling surface to be easily increased, thus achieving better dissipation of the heat generated by the capacitor and the heat transferred from the first electrical component and the second electrical component.

[0027] Furthermore, it is preferably provided that the first cooling plate is cross-shaped and the second cooling plate and the third cooling plate are each L-shaped.

[0028] According to the invention, the object is further achieved by a motor unit, which is characterized in that it comprises: a motor; and a power conversion device according to one of the above embodiments, wherein the power conversion device converts direct current provided by a power supply into alternating current and supplies it to the motor. (Effects of the invention)

[0029] According to the present invention, the bus comprises the first bus, which has the first extension section extending along the second surface. The side of the first bus opposite the first surface serves for electrical connection to the first electrical component. The first cooling plate is provided on the first surface, and the second cooling plate is provided on the second surface such that the first extension section is at least partially covered.Thus, in addition to dissipating the heat generated by the capacitor using the first cooling plate on the first surface side, the heat transferred from the first electrical component to the capacitor via the first bus can be further dissipated by means of the second cooling plate on the second surface side, and furthermore, the capacitor can be cooled from two directions, thereby suppressing the influence of the heat transferred from the first electrical component on an operation of the capacitor. Short description of the characters Fig. 1 shows a block diagram of a vehicle drive unit including a motor unit according to an embodiment of the present invention. Fig. 2 shows a side view of a power conversion device included in the motor unit according to the embodiment of the present invention. Fig. 3 shows a simplified front view of the power conversion device included in the motor unit according to the embodiment of the present invention. (List of reference symbols) 1 vehicle control unit 100 Motor unit 110 engine 111 Drive motor 112 Regenerative Motor 120 current conversion device 121 Capacitor 1211 housing 1212 capacitor element 122 Power module 1221 First power module 1222 Second power module 123 Cooling flow path section 1231 Inlet 1232 outlet 124 Cooling component 130 Capacitor 140 DC-DC conversion circuit 150 circuit boards 151 microcontrollers 200 high-voltage power supply 300 vehicle axle 400 Low voltage supply 500 Electronic vehicle control unit BS Bus BS1 First Bus BS11 First extension section BS2 Second Bus BS21 Second extension section BS3 connecting section P1 First cooling plate P2 Second cooling plate P3 Third cooling plate S1 First Surface S2 Second Surface S3 Third Surface S4 Fourth Surface S5 Fifth Surface Detailed embodiments

[0030] The motor unit according to an embodiment of the present invention will be described below with reference to Fig. 1 to 3. Showing: Fig. 1 is a block diagram of a vehicle drive unit including the motor unit according to an embodiment of the present invention, Fig. 2 is a side view of a power conversion device included in the motor unit according to the embodiment of the present invention, and Fig. 3 is a simplified front view of the power conversion device included in the motor unit according to the embodiment of the present invention.

[0031] For ease of explanation, three mutually orthogonal directions are referred to as the X, Y, and Z directions, respectively. One side of the X, Y, or Z direction is designated X1, Y1, or Z1, respectively, and the other side of the X, Y, or Z direction is designated X2, Y2, or Z2, respectively. (Structure of the vehicle control unit)

[0032] As in Fig. 1, a vehicle control unit 1 includes a motor unit 100 and a high-voltage power supply 200. The motor unit 100 includes: a motor 110; and a power conversion device 120, wherein the power conversion device 120 converts power provided by the high-voltage power supply 200 into suitable alternating current and supplies it to the motor 110.

[0033] The motor unit 100 further comprises a capacitor 130 and a DC-DC conversion circuit 140, as can be seen from Fig. 1. Furthermore, the motor 110 comprises a drive motor 111 and a regenerative motor 112. In addition, the power conversion device 120 has a capacitor 121 and a power module 122. The power module 122 comprises a first power module 1221 and a second power module 1222. Furthermore, the high-voltage supply 200, the capacitor 130, the DC-DC conversion circuit 140, the capacitor 121, and the power module 122 are connected in series. During regular operation, power supplied by the high voltage power supply 200 is supplied to the first power module 1221 and the second power module 1222 via the capacitor 130, the DC-DC conversion circuit 140, and the capacitor 121, respectively, and then to the drive motor 111 and the regenerative motor 112, respectively, and a vehicle axle 300 is driven by the drive motor 111.During regenerative operation, power provided by the regenerative motor 112 is supplied to the drive motor 111 via the first power module 1221 and the second power module 1222 to drive the vehicle axle 300. Since two motors and two power modules are included, higher output power and load are achieved compared to the embodiment including one motor and one power module.

[0034] As in Fig. As shown in Figure 1, the vehicle control unit 1 further comprises a low-voltage power supply 400 and an electronic vehicle control unit 500. The motor unit 100 further comprises a circuit board 150, with a microcontroller 151 provided on the circuit board 150. The low-voltage power supply 400 supplies the circuit board 150 with power. The electronic vehicle control unit 500 supplies the microcontroller 151 with a control signal. (Structure of the current conversion device)

[0035] As stated above, the power conversion device 120 includes the capacitor 121 and the power module 122. The power module 122 includes the first power module 1221 and the second power module 1222.

[0036] As in Fig. 2 and Fig. 3, the power conversion device 120 further comprises a cooling flow path section 123, wherein the cooling flow path section 123 serves to cool the capacitor 121 and the power module 122.

[0037] As can be seen from Fig. 2 and Fig. 3, the capacitor 121 further comprises a first surface S1 and a second surface S2 that intersect (in the illustrated example, they run perpendicular to each other, but this is not a limitation here), and a bus BS. The bus BS comprises a first bus BS1, wherein the first bus BS1 has a first extension section BS11 that extends along the second surface S2. A side of the first bus BS1 opposite the first surface S1 (in the illustrated example, the side in the Z1 direction) serves for electrical connection to the first power module 1221, which functions as a first electrical component.A first cooling plate P1 is provided on the first surface S1 and a second cooling plate P2 is provided on the second surface S2 such that the first extension section BS11 is at least partially covered (in the example shown, substantially the entire first extension section BS11 is covered).

[0038] As in Fig. 2 and Fig. 3, the capacitor 121 further comprises a third surface S3 that intersects the first surface S1 (in the illustrated example, it is perpendicular thereto, but this is not limited here) and is different from the second surface S2. The bus BS comprises a second bus BS2, the second bus BS2 having a second extension section BS21 extending along the third surface S3. A side of the second bus BS2 opposite the first surface S1 (in the illustrated example, the Z1-direction side) is used for electrical connection to the second power module 1222, which functions as a second electrical component. A third cooling plate P3 is provided on the third surface S3 such that the second extension section BS21 is at least partially covered (in the illustrated example, substantially the entire second extension section BS21 is covered).(In the example shown, the second surface S2 and the third surface S3 are oriented in opposite directions. The second surface S2 points in the Y1 direction. The third surface S3 points in the Y2 direction).

[0039] As can be seen from Fig. 2 and Fig. 3, the capacitor 121 further has a fourth surface S4, wherein the fourth surface S4 is connected to the first surface S1, the second surface S2, and the third surface S3. A cooling component 124 is provided between the fourth surface S4 and the cooling flow path section 123, wherein the cooling component 124 dissipates the heat from the fourth surface S4 to the cooling flow path section 123.

[0040] As in Fig. 2 and Fig. 3, the capacitor 121 further includes a fifth surface S5, and the fifth surface S5 and the first surface S1 are oriented in opposite directions. The fifth surface S5 is connected to the second surface S2, the third surface S3, and the fourth surface S4. The first power module 1221 and the second power module 1222 are located between the fifth surface S5 and the cooling flow path section 123. The first power module 1221 and the second power module 1222 are in direct or indirect contact with the cooling flow path section 123 on a side opposite the fifth surface S5.

[0041] As can be seen from Fig. 2 and Fig. 3, the bus BS further comprises a connecting section BS3 extending along the first surface S1 and connecting the first bus BS1 to the second bus BS2. The first cooling plate P1 at least partially covers the connecting section BS3.

[0042] As in Fig. 2 and Fig. As shown in Figure 3, the second cooling plate P2 and the third cooling plate P3 are each connected to the first cooling plate P1, and the heat from the second cooling plate P2 and the third cooling plate P3 is dissipated to the cooling flow path portion 123 via the first cooling plate P1. Furthermore, the first cooling plate P1 is cross-shaped, and the second cooling plate P2 and the third cooling plate P3 are each L-shaped.

[0043] As can be seen from Fig. 2 and Fig. 3, the first cooling plate P1, the second cooling plate P2, and the third cooling plate P3 are each a metal plate, and an insulating layer is provided between the connecting portion BS3 and the first cooling plate P1, between the first bus BS1 and the second cooling plate P2, and between the second bus BS2 and the third cooling plate P3. In detail, the capacitor 121 includes a resin case 1211 and a capacitor element 1212 (made of, for example, a thin-film capacitor) embedded in the case 1211. The first extension portion BS11, the second extension portion BS21, and the connecting portion BS3 are embedded near the surface of the case 1211, and the first cooling plate P1, the second cooling plate P2, and the third cooling plate P3 are in contact with the surface of the case 1211.Furthermore, the first bus BS1 and the second bus BS2 are connected, for example, via the connecting section BS3 to the capacitor element 1212, which functions as a heat generating component.

[0044] In addition, the first power module 1221 and the second power module 1222 each have, for example, a plurality of switching elements (each consisting of, for example, an IGBT element) so that a heat generating component is formed, although this is not shown.

[0045] Furthermore, the cooling flow path section 123, as shown in Fig. 2 and Fig.3, an inlet 1231 and an outlet 1232, and extends in a generally Z-shaped manner. It includes a first plate-shaped portion located closer to the Z1 direction than the power module 122 and whose thickness substantially corresponds to the Z direction, a second plate-shaped portion located closer to the X1 direction than the power module 122 and whose thickness substantially corresponds to the X direction, and a third plate-shaped portion located closer to the X1 direction than the power module 122 and whose thickness substantially corresponds to the Z direction. Water or another cooling fluid flows into the cooling flow path portion 123 via the inlet 1231, meanders, and then flows out of the outlet 1232. (Main effects of the present embodiment)

[0046] In the motor unit 100 according to the present embodiment, the bus BS includes the first bus BS1, the first bus BS1 having the first extension portion BS11 extending along the second surface S2. The side of the first bus BS1 opposite the first surface S1 is used for electrical connection to the first power module 1221, which functions as the first electrical component. The first cooling plate P1 is provided on the first surface S1, and the second cooling plate P2 is provided on the second surface S2 such that the first extension portion BS11 is at least partially covered.Thus, in addition to dissipating the heat generated by the capacitor 121 using the first cooling plate P1 on the first surface S1 side, the heat transferred from the first power module 1221 to the capacitor 121 via the first bus BS1 can be further dissipated by means of the second cooling plate P2 on the second surface S2 side, and further, the capacitor 121 can be cooled from two directions, thereby suppressing the influence of the heat transferred from the first power module 1221 on an operation of the capacitor 121.

[0047] So far, the invention has been described by way of example in connection with the figures, but the concrete implementation of the invention should of course not be limited to these embodiments.

[0048] For example, in the above embodiments, the first electrical component and the second electrical component were described using the first power module 1221 and the second power module 1222, respectively, but this is not limited to this. Rather, the first electrical component and the second electrical component may be heat-generating components other than power modules.

[0049] Furthermore, in the above embodiments, the cooling flow path section 123 is included for cooling the first cooling plate P1, the second cooling plate P2, and the third cooling plate P3, but this is not limited to this. Rather, the cooling flow path section 123 may be omitted.

[0050] Furthermore, in the above embodiments, the first cooling plate P1 is cross-shaped, and the second cooling plate P2 and the third cooling plate P3 are each L-shaped, but this is not limited to this. Rather, the shapes of the first cooling plate P1, the second cooling plate P2, and the third cooling plate P3 can be appropriately selected as needed.

[0051] Furthermore, in the above embodiments, the second cooling plate P2 and the third cooling plate P3 are each connected to the first cooling plate P1, but this is not limited to this. Rather, the second cooling plate P2 and the third cooling plate P3 may be formed independently of the first cooling plate P1.

[0052] Furthermore, in the above embodiments, it is conceivable that the first cooling plate P1, the second cooling plate P2 and the third cooling plate P3 are cooled by air cooling.

[0053] Furthermore, in the above embodiments, the first bus BS1 and the second bus BS2 are connected to each other via the connecting section BS3, but this is not limited to this. Rather, the connecting section BS3 may be omitted, so that the first bus BS1 and the second bus BS2 are each directly connected to the capacitor element 1212.

[0054] Furthermore, in the above embodiments, the second cooling plate P2 and the third cooling plate P3 are provided simultaneously, but this is not limited to this. Rather, it is conceivable that only one of the components, the second cooling plate P2 and the third cooling plate P3, is provided.

[0055] Furthermore, in the above embodiments, the first power module 1221 and the second power module 1222 are provided simultaneously, but this is not limited to this. Rather, it is conceivable that only one of the first power module 1221 and the second power module 1222 is provided.

[0056] It is to be understood that, within the scope of the invention, the individual parts of the embodiments can be freely combined with one another or suitably modified or dispensed with.

Claims

[1] A power conversion device (120) comprising: a capacitor (121) having a first surface (S1) and a second surface (S2) which intersect, and a bus (BS), wherein the bus (BS) comprises a first bus (BS1) having a first extension section (BS11) extending along the second surface (S2), wherein a side of the first bus (BS1) opposite the first surface (S1) serves for electrical connection to a first electrical component, a first cooling plate (P1) is provided on the first surface (S1), and a second cooling plate (P2) is provided on the second surface (S2) such that the first extension section (BS11) is at least partially covered, the capacitor (121) further comprises a third surface (S3) which intersects the first surface (S1) and is different from the second surface (S2), the bus (BS) comprises a second bus (BS2) having a second extension section (BS21) extending along the third surface (S3), wherein a side of the second bus (BS2) opposite the first surface (S1) serves for electrical connection to a second electrical component, and a third cooling plate (P3) is provided on the third surface (S3) such that the second extension section (BS21) is at least partially covered, the power conversion device further comprising: a first power module (1221) as the first electrical component, a second power module (1222) as the second electrical component, and a cooling flow path section (123) to which the heat from the second cooling plate (P2) and the third cooling plate (P3) is dissipated via the first cooling plate (P1), wherein: the capacitor (121) further comprises a fourth surface (S4) connected to the first surface (S1), the second surface (S2) and the third surface (S3), respectively, a cooling component (124) is provided between the fourth surface (S4) and the cooling flow path section (123), which dissipates the heat from the fourth surface (S4) to the cooling flow path section (123). the capacitor (121) further comprises a fifth surface (S5) which and the first surface (S1) are oriented in opposite directions, wherein the fifth surface (S5) is connected to the second surface (S2), the third surface (S3) and the fourth surface (S4), the first power module (1221) and the second power module (1222) are located between the fifth surface (S5) and the cooling flow path section (123), and the side of the first power module (1221) and the second power module (1222) opposite the fifth surface (S5) are in direct or indirect contact with the cooling flow path section (123). [2] The power conversion device (120) according to claim 1, characterized by that the second surface (S2) and the third surface (S3) are oriented in opposite directions. [3] The power conversion device (120) according to claim 1, characterized by , that the bus (BS) comprises a connecting section (BS3) extending along the first surface (S1) and connecting the first bus (BS1) to the second bus (BS2), wherein the first cooling plate (P1) at least partially covers the connecting section (BS3). [4] The power conversion device (120) according to claim 3, characterized by , that the first cooling plate (P1), the second cooling plate (P3) and the third cooling plate (P3) are each metal plates, wherein an insulating layer is provided between the connecting section (BS3) and the first cooling plate (P1), between the first bus (BS1) and the second cooling plate (P2), and between the second bus (BS2) and the third cooling plate (P3). [5] The power conversion device (120) according to one of claims 1 to 4, characterized by , that the capacitor (121) comprises a resin casing (1211) and a capacitor element (1212) embedded in the casing (1211), wherein the first extension portion (BS11) and the second extension portion (BS21) are embedded near the surface of the housing (1211) and wherein the first cooling plate (P1), the second cooling plate (P2) and the third cooling plate (P3) abut against a surface of the housing (1211). [6] The power conversion device (120) according to one of claims 1 to 4, characterized by that the second cooling plate (P2) and the third cooling plate (P3) are each connected to the first cooling plate (P1). [7] The power conversion device (120) according to one of claims 1 to 4, characterized by , that the first cooling plate (P1) is cross-shaped, and the second cooling plate (P2) and the third cooling plate (P3) are each L-shaped. [8] A motor unit (100), characterized by that has: an engine (110); and a power conversion device (120) according to any one of claims 1 to 7, which converts a direct current provided by a power supply into alternating current and supplies it to the motor (110).

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