Power conversion apparatus, powertrain and electric vehicle

Abstract

Provided in the present application are a power conversion apparatus, a powertrain and an electric vehicle, relating to the technical field of power electronics. The power conversion apparatus comprises a circuit board, a power module and an integrated magnetic device, the integrated magnetic device and the power module being separately and electrically connected to the circuit board, and the power module and the circuit board being arranged on a same side of the integrated magnetic device. The integrated magnetic device comprises a heat dissipation housing and a plurality of magnetic components. The heat dissipation housing is internally provided with a plurality of accommodating cavities, which at least comprise a first accommodating cavity and a second accommodating cavity. The plurality of magnetic components at least comprise a first magnetic component and a second magnetic component, the first magnetic component being located in the first accommodating cavity, and the second magnetic component being located in the second accommodating cavity. In the present application, the plurality of magnetic components are integrated in the integrated magnetic device, such that integrated heat dissipation of the magnetic components can be achieved, thereby improving the loss density of the magnetic components, and reducing the loss of the power conversion apparatus.

Description

Power conversion device, power assembly and electric vehicle

[0001] Cross-reference to related applications

[0002] The present application claims priority to the Chinese patent application No. 202411359598.3, filed on September 26, 2024, and entitled “A power conversion device, power assembly and electric vehicle”, the entire content of which is incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to the field of power electronics, and in particular to a power conversion device, power assembly and electric vehicle. BACKGROUND

[0004] In recent years, with the increasing demand for energy saving and environmental protection, the proportion of new energy vehicles in the market has also increased year by year. The on board charger (OBC) is an important part of the power system in new energy vehicles, which is used to charge the power battery of electric vehicles with the power of charging piles. The OBC mainly has the functions of rectification charging, direct current output and power distribution for vehicles. The OBC includes a power factor correction (PFC) module, a direct current-direct current converter (DC-DC) module and an LLC (inductance inductance capacitance) module, etc. The magnetic devices in these modules cooperate with power tubes to act as voltage ratio functions in the OBC.

[0005] As the OBC works for a long time, the magnetic devices in the OBC will generate heat. However, due to the relatively dispersed distribution of the magnetic devices, the heat dissipation efficiency of the magnetic devices is low, resulting in a high internal temperature of the OBC, which affects the working efficiency of the magnetic devices and other devices, and even causes damage to the magnetic devices and other devices. Moreover, the dispersed layout of the magnetic devices is not conducive to the development of high density and integration of the OBC. SUMMARY

[0006] The present application provides a power conversion device, power assembly and electric vehicle to realize the integrated layout of the magnetic devices in the power conversion device, so as to realize the integrated heat dissipation of the magnetic devices, and further improve the magnetic device loss density in the power conversion device, so as to reduce the loss of the power conversion device.

[0007] In a first aspect, the present application provides a power conversion device. The power conversion device comprises a circuit board, a power module and an integrated magnetic device. The integrated magnetic device and the power module are electrically connected to the circuit board, and the power module and the circuit board are arranged on the same side of the integrated magnetic device. Specifically, the integrated magnetic device comprises a heat dissipation shell and a plurality of magnetic devices. A partition wall is arranged in the heat dissipation shell. The partition wall divides the internal space of the heat dissipation shell into a plurality of accommodation cavities. The plurality of accommodation cavities can at least include a first accommodation cavity and a second accommodation cavity. The plurality of magnetic devices at least include a first magnetic device and a second magnetic device. In the heat dissipation shell, the first magnetic device is placed in the first accommodation cavity, and the second magnetic device is placed in the second accommodation cavity.

[0008] In the power conversion device of the present application, the integrated magnetic device centrally arranges the plurality of magnetic devices in the heat dissipation shell, so that the heat of the plurality of magnetic devices can be concentrated and dissipated through the heat dissipation shell. The integrated magnetic device can realize the integrated layout of the magnetic devices and the integrated heat dissipation of the magnetic devices, thereby improving the magnetic device loss density inside the power conversion device and reducing the loss of the power conversion device.

[0009] In a possible implementation, the thermal conductivity of the partition wall is less than the thermal conductivity of the heat dissipation shell, so that the heat of the magnetic devices can be transferred to the heat dissipation shell, and the heat transfer between the magnetic devices of adjacent two accommodation cavities can be reduced. The partition wall can be made of different materials from the heat dissipation shell. Specifically, the partition wall can be made of a material with low thermal conductivity, for example, made of plastic, to reduce the manufacturing cost. In this technical solution, the partition wall can be detachably connected to the heat dissipation shell. Alternatively, in another possible implementation, the partition wall can be integrally formed with the heat dissipation shell. Therefore, the heat of the magnetic devices can also be transferred to the heat dissipation shell through the partition wall, thereby increasing the heat dissipation area.

[0010] In a possible implementation, at least one heat dissipation protrusion is arranged on the inner wall of the plurality of accommodation cavities. One of the at least one heat dissipation protrusion corresponds to a recess of the first magnetic device or the second magnetic device, so that the heat conduction path between the recess area and the inner wall can be shortened, and the heat conduction path between the outer surface of the magnetic device and the inner wall can be more uniform.

[0011] In a possible implementation, in the plurality of accommodation cavities, the distance between the surface of the magnetic device in each accommodation cavity and the inner wall of each accommodation cavity is less than or equal to a set threshold value, so as to reduce the heat conduction path of the magnetic device and the heat dissipation shell, reduce the heat dissipation resistance, and reduce the amount of potting glue, thereby reducing the cost. In a specific technical solution, the set threshold value can be set to 4 mm.

[0012] In a possible implementation, the inner wall of the plurality of accommodation cavities is provided with a plurality of heat dissipation teeth arranged in an array. The plurality of heat dissipation teeth can increase the heat dissipation area between the heat dissipation shell and the magnetic devices, and further improve the heat dissipation efficiency.

[0013] In a possible implementation, the high heat loss area of the first magnetic device is arranged in a direction away from the second accommodation cavity, and the high heat loss area of the second magnetic device is arranged in a direction away from the first accommodation cavity. In this way, the low heat loss area of the magnetic device is placed close to the central position of the heat dissipation shell, and the high heat loss area of the magnetic device is placed close to the outer periphery of the heat dissipation shell, realizing the layout of low temperature aggregation and high temperature externalization, so that most of the heat of the magnetic device can be directly transmitted through the heat dissipation shell, to reduce the thermal coupling between the magnetic devices.

[0014] In a possible implementation, the power conversion device can include an on-board charger. Specifically, the first magnetic device includes a DC-DC transformer and a DC-DC inductor, and the second magnetic device includes an LLC transformer and an LLC inductor. This technical solution can realize the integrated layout and integrated heat dissipation of the DC-DC magnetic device and the LLC magnetic device of the on-board charger.

[0015] In a possible implementation, the heat loss of the DC-DC transformer is less than the heat loss of the DC-DC inductor, the DC-DC transformer is arranged in a direction close to the second accommodation cavity, and the DC-DC inductor is located on the side of the DC-DC transformer away from the second accommodation cavity. The heat loss of the LLC transformer is less than the heat loss of the LLC inductor, the LLC transformer is arranged in a direction close to the first accommodation cavity, and the LLC inductor is located on the side of the LLC transformer away from the first accommodation cavity. In the first accommodation cavity and the second accommodation cavity, the magnetic device with lower heat loss is placed close to the central position of the heat dissipation shell, and the magnetic device with higher heat loss is placed close to the outer periphery of the heat dissipation shell, realizing the layout of low temperature aggregation and high temperature externalization, so that most of the heat of the magnetic device can be directly transmitted through the heat dissipation shell, to reduce the thermal coupling between the magnetic devices.

[0016] In a possible implementation, the power conversion device further includes a DC-DC converter and a power distribution unit (PDU), and the DC-DC converter and the PDU are respectively located on the side of the integrated magnetic device. The power conversion device in this technical solution can integrate the OBC, the DC-DC converter and the PDU, which is conducive to the integration and light weight of the power assembly.

[0017] In one possible implementation, the power conversion device further comprises a first cooling plate and a second cooling plate arranged oppositely. The first cooling plate is provided with a first cooling flow channel, and the second cooling plate is provided with a second cooling flow channel. The circuit board is located between the first cooling plate and the second cooling plate. The power module is located between the second cooling plate and the circuit board, and the integrated magnetic device is located between the first cooling plate and the circuit board. In this technical solution, the integrated magnetic device can be cooled by the first cooling plate, and the power module can be cooled by the second cooling plate, so that the heat in the power conversion device is transmitted to the outside.

[0018] Of course, the integrated magnetic device can be cooled by multiple cooling plates to increase the heat dissipation efficiency. In another possible implementation, the power conversion device further comprises a first cooling plate and a second cooling plate arranged oppositely. The first cooling plate is provided with a first cooling flow channel, and the second cooling plate is provided with a second cooling flow channel. The circuit board is located on the side of the second cooling plate away from the first cooling plate. The power module is located between the circuit board and the second cooling plate, and the integrated magnetic device is located between the first cooling plate and the second cooling plate. Therefore, the integrated magnetic device can be cooled by the first cooling plate and the second cooling plate.

[0019] In one possible implementation, the first cooling plate can be part of the shell of the power conversion device. Specifically, the power conversion device can further comprise a cover plate and multiple side plates. The cover plate is arranged opposite to the first cooling plate. The multiple side plates are connected in sequence and located between the cover plate and the first cooling plate. The cover plate, the multiple side plates, and the first cooling plate enclose the shell of the power conversion device, and the circuit board, the power module, the integrated magnetic device, and the second cooling plate are located in the shell. The second cooling plate is located between the integrated magnetic device and the cover plate, and the heat dissipation shell is fixedly connected to the side surface of the first cooling plate facing the cover plate. In this technical solution, further, the heat dissipation shell can also be detachably connected to the first cooling plate, so that the integrated magnetic device can be integrally detached for maintenance or replacement.

[0020] In one possible implementation, a heat-conducting pad is arranged between the heat dissipation shell and the first cooling plate, and the heat-conducting coefficient of the heat-conducting pad is greater than the heat-conducting coefficient of the barrier wall. The heat of the heat dissipation shell is transmitted to the shell through the heat-conducting pad, thereby increasing the heat dissipation rate.

[0021] In another possible implementation, the first cooling plate can also be independently arranged relative to the shell of the power conversion device. The power conversion device can further comprise a bottom shell and a cover plate, and the cover plate covers the bottom shell. The circuit board, the power module, the integrated magnetic device, and the second cooling plate are located in the bottom shell. The first cooling plate is fixedly connected to the side of the bottom shell away from the cover plate, and the second cooling plate is located between the integrated magnetic device and the cover plate. In this technical solution, further, the heat dissipation shell can also be an integral structure with the bottom shell, that is, the bottom plate of the heat dissipation shell can be part of the bottom shell, so that the height dimension of the power conversion device can be reduced.

[0022] In a possible implementation, at least one of the plurality of accommodation cavities comprises a through hole towards the side of the first cooling plate, and the magnetic device in the at least one accommodation cavity extends out of the through hole. The magnetic device extends out of the heat dissipation shell, which can shorten the heat conduction distance between the magnetic device and the first cooling channel, thereby reducing the heat dissipation thermal resistance, and meanwhile, the material usage of the heat dissipation shell is reduced, which can reduce the cost.

[0023] In the power converter of the present application, the specific number of the plurality of magnetic devices is not limited to two, and the magnetic devices can be independently placed in different accommodation cavities. In a possible implementation, when the power conversion device is a vehicle charger, the plurality of accommodation cavities further comprises a third accommodation cavity, and the first accommodation cavity and the second accommodation cavity are arranged adjacent to the third accommodation cavity. The plurality of magnetic devices further comprises a third magnetic device, and the third accommodation cavity is used to accommodate the third magnetic device, and the third magnetic device is a PFC magnetic device.

[0024] In a possible implementation, the openings of the first accommodation cavity, the second accommodation cavity and the third accommodation cavity are towards the same direction, which can facilitate the installation and disassembly of the magnetic devices. Moreover, the first accommodation cavity, the second accommodation cavity and the third accommodation cavity are arranged in a triangular shape, which can realize the miniaturization of the heat dissipation shell. In another possible implementation, the openings of at least two of the first accommodation cavity, the second accommodation cavity and the third accommodation cavity are towards different directions. In this technical solution, the heat dissipation shell has different openings, so that the magnetic devices can be installed and disassembled from different directions according to the actual application scenario.

[0025] In a possible implementation, the first accommodation cavity and the first magnetic device, and the second accommodation cavity and the second magnetic device are respectively filled with potting glue, and the thermal conductivity of the potting glue is greater than that of the barrier wall. The potting glue not only can fix the magnetic device in the heat dissipation shell, but also can transfer the heat of the magnetic device to the heat dissipation shell.

[0026] In a second aspect, the present application provides a power assembly. The power assembly comprises a motor, a reducer and the power conversion device of the first aspect. The motor is connected with the power conversion device, and the motor is connected with the reducer. In the power assembly, the power conversion device can provide electric energy to the motor, so that the motor can operate. The input shaft of the reducer is in driving connection with the output shaft of the motor, and is used to transmit the kinetic energy of the motor. In the power assembly, the integrated magnetic device of the power conversion device can realize the integrated layout and integrated heat dissipation of the magnetic device, thereby improving the magnetic device loss density in the power conversion device, reducing the loss of the power conversion device, and further improving the working efficiency of the power assembly.

[0027] In a third aspect, the present application provides an electric vehicle. The electric vehicle comprises a power battery and the power assembly of the second aspect. The power conversion device of the power assembly is configured to charge the power battery, and the power battery is configured to provide direct current to the power assembly. In the electric vehicle of the present application, the loss inside the power conversion device is small, and the efficiency of the power conversion device charging the power battery can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0028] Fig. 1 is a schematic diagram of charging of an electric vehicle according to an embodiment of the present application;

[0029] Fig. 2 is a schematic diagram of a power system of an electric vehicle according to an embodiment of the present application;

[0030] Fig. 3 is a schematic diagram of a power conversion device according to an embodiment of the present application;

[0031] Fig. 4 is another schematic diagram of a power conversion device according to an embodiment of the present application;

[0032] Fig. 5 is a schematic diagram of an integrated magnetic device according to an embodiment of the present application;

[0033] Fig. 6 is another schematic diagram of an integrated magnetic device according to an embodiment of the present application;

[0034] Fig. 7 is an exploded schematic diagram of an integrated magnetic device according to an embodiment of the present application;

[0035] Fig. 8 is a schematic diagram of a heat dissipation shell according to an embodiment of the present application;

[0036] Fig. 9 is a layout schematic diagram of a first magnetic device, a second magnetic device and a third magnetic device according to an embodiment of the present application;

[0037] Fig. 10 is another exploded schematic diagram of an integrated magnetic device according to an embodiment of the present application;

[0038] Fig. 11 is a sectional view of the heat dissipation shell and the third magnetic device along the direction A-A in Fig. 8;

[0039] Fig. 12 is a sectional view of the heat dissipation shell and the second magnetic device along the direction B-B in Fig. 8;

[0040] Fig. 13 is another exploded schematic diagram of the heat dissipation shell and the magnetic device according to an embodiment of the present application;

[0041] Fig. 14 is another layout schematic diagram of the first magnetic device, the second magnetic device and the third magnetic device according to an embodiment of the present application;

[0042] Fig. 15 is another layout schematic diagram of the first magnetic device, the second magnetic device and the third magnetic device according to an embodiment of the present application;

[0043] Fig. 16 is another layout schematic diagram of the first magnetic device, the second magnetic device and the third magnetic device according to an embodiment of the present application;

[0044] Fig. 17 is another layout schematic diagram of the first magnetic device, the second magnetic device and the third magnetic device according to an embodiment of the present application;

[0045] Fig. 18 is another layout schematic diagram of the first magnetic device, the second magnetic device and the third magnetic device according to an embodiment of the present application;

[0046] Fig. 19 is another schematic diagram of the power conversion device according to an embodiment of the present application;

[0047] Fig. 20 is another schematic diagram of the power conversion device according to an embodiment of the present application;

[0048] Fig. 21 is another schematic diagram of the heat dissipation shell according to an embodiment of the present application;

[0049] Fig. 22 is another schematic diagram of the power conversion device according to an embodiment of the present application.

[0050] Reference signs: 10-electric vehicle 11-power battery 12-power assembly 20-power conversion device 21-outer shell 22-circuit board 23-power module 24-integrated magnetic device 25-DC-DC converter 26-PDU 211-bottom shell 212-cover plate 213-first cooling plate 214-second cooling plate 215-thermally conductive pad 241-heat dissipation shell 242-first magnetic device 243-second magnetic device 244-third magnetic device 2411-first receiving cavity 2412-second receiving cavity 2413-third receiving cavity 2414-barrier wall 2415-heat dissipation protrusion 2416-heat dissipation tooth 2417-first through hole 2418-second through hole 2419-third through hole 2421-DC-DC transformer 2422-DC-DC inductor 2431-LLC transformer 2432-LLC inductor DETAILED DESCRIPTION

[0051] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings.

[0052] For the convenience of understanding the power conversion device, power assembly and electric vehicle provided by the embodiments of the present application, the application scenarios are described as follows. With the gradual maturity of the electric vehicle technology, users have higher and higher requirements for the performance of electric vehicles. FIG. 1 is a charging schematic diagram of an electric vehicle provided by an embodiment of the present application, and FIG. 2 is a power system schematic diagram of an electric vehicle provided by an embodiment of the present application. As shown in FIG. 1 and FIG. 2, the electric vehicle 10 includes a power battery 11 and a power assembly 12. The power assembly 12 can include a power conversion device 20, a motor and a reducer. Further, the power conversion device 20 can include at least one of a motor control unit (MCU), an OBC, a DC-DC converter and a PDU. Among them, the motor control unit (MCU) can be used to control the motor. The OBC is used to be connected with a charging pile and charge the power battery 11. The power battery 11 is used to provide electric energy for the electric vehicle 10. In the electric vehicle 10, the charging problem of the power battery 11 is a key problem that determines the performance and user experience of the electric vehicle 10. At present, the charging modes of the power battery 11 in the electric vehicle 10 mainly include fast charging and slow charging. Among them, the fast charging is that the direct current (DC) is directly charged to the power battery 11 by the direct current charging pile. The slow charging is that the alternating current (AC) is directly connected to the electric vehicle 10 by the alternating current charging pile, and then the alternating current is converted into direct current by the OBC, and then the power battery 11 is charged. Specifically, the power conversion device 20 includes a plurality of magnetic devices. For example, the OBC includes a PFC circuit, a DC-DC circuit and an LLC resonant circuit, each of which includes at least one magnetic device. Among them, the PFC circuit converts the alternating current connected into direct current, and then the DC-DC circuit and the LLC resonant circuit convert the direct current from the PFC circuit into high-voltage direct current to charge the power battery 11.

[0053] In the present application, the OBC is used to convert the direct current of the charging pile into alternating current and supply it to the power battery 11 for charging. The power battery 11 can also provide direct current to the OBC, which is converted into alternating current by the OBC to supply external alternating current electrical equipment, such as charging other vehicles in the vehicle emergency rescue scene, or charging small electronic devices. Of course, the OBC can also output the direct current of the power battery 11 to the DC-DC converter. The DC-DC converter can output 9V-16V low-voltage direct current to charge the vehicle storage battery (such as 12V storage battery). The PDU can be connected with the power battery 11, the OBC, the DC-DC converter, the MCU and other components respectively to distribute power to these components and ensure the safety of the whole vehicle power supply.

[0054] In current power conversion devices, taking OBC as an example, the PFC circuit, the DC-DC circuit and the LLC resonant circuit each include at least one magnetic device. For example, the PFC circuit includes a PFC inductor, the DC-DC magnetic device includes a DC-DC inductor and a DC-DC transformer, and the LLC resonant circuit includes an LLC inductor and an LLC transformer. However, these magnetic devices are dispersed in the OBC. When the OBC is in a working state for a long time, the magnetic devices will gradually generate heat, so that the heat at multiple positions inside the OBC is high.

[0055] In view of this, the present application provides a power conversion device, a power assembly and an electric vehicle, so as to realize the integrated layout of the magnetic devices in the power conversion device, thereby realizing the integrated heat dissipation of the magnetic devices, and further improving the magnetic device loss density inside the power conversion device, so as to reduce the loss of the power conversion device.

[0056] It should be noted that the terms used in the following embodiments are only for the purpose of describing specific embodiments and are not intended to be limiting on the present application. As used in the specification and the appended claims of the present application, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0057] In this specification, the reference to “one embodiment” or “some embodiments” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the application. The appearances of the phrases “in one embodiment,” “in some embodiments,” “in other embodiments,” “in additional embodiments,” and so on, in various places in the specification are not necessarily all referring to the same embodiment, unless otherwise specifically stated. The terms “including,” “containing,” “having,” and variations thereof mean “including but not limited to,” unless expressly specified otherwise.

[0058] In this application, the terms “first,” “second,” and so on are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with “first,” “second” can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of “a plurality of” is two or more.

[0059] In addition, in this document, "top", "bottom", "upper", "lower", and other orientation terms are defined with respect to the orientation of the structures as shown in the figures, and it is understood that these directional terms are relative concepts, which are used for relative description and clarification, and can change accordingly according to the change of the orientation of the structure.

[0060] In the electric vehicle 10 of the present application, the power assembly 12 can adopt a stacked structure. For example, the input shaft of the reducer is connected with the output shaft of the motor, and the power conversion device 20 is stacked on top of the motor and the reducer. The MCU is connected with the power battery 11, and can be used to convert the direct current of the power battery 11 into alternating current and output to the motor. The motor converts electric energy into kinetic energy and drives the electric vehicle 10 to run through the reducer.

[0061] Fig. 3 is a schematic diagram of the power conversion device provided by the embodiment of the present application, and Fig. 4 is another schematic diagram of the power conversion device provided by the embodiment of the present application. As shown in Figs. 3 and 4, the power conversion device 20 includes a shell 21, and a circuit board 22, a power module 23 and an integrated magnetic device 24 placed in the shell 21. The power module 23 and the integrated magnetic device 24 are respectively electrically connected with the circuit board 22, and the power module 23 and the integrated magnetic device 24 can be electrically connected through the circuit board 22. The power module 23 and the circuit board 22 are arranged on the same side of the integrated magnetic device 24.

[0062] The integrated magnetic device 24 includes a heat dissipation shell 241 and a plurality of magnetic devices, and the heat dissipation shell 241 is used to accommodate the plurality of magnetic devices. A baffle wall is arranged in the heat dissipation shell 241, and the baffle wall divides the internal space of the heat dissipation shell 241 into a plurality of accommodation cavities. The plurality of accommodation cavities can include at least two accommodation cavities. The plurality of magnetic devices includes at least two magnetic devices.

[0063] Fig. 5 is a schematic diagram of the integrated magnetic device provided by the embodiment of the present application. As shown in Fig. 5, in one embodiment, the plurality of accommodation cavities includes a first accommodation cavity 2411 and a second accommodation cavity 2412, and the plurality of magnetic devices includes a first magnetic device 242 and a second magnetic device 243. In the heat dissipation shell 241, the first magnetic device 242 is placed in the first accommodation cavity 2411, and the second magnetic device 243 is placed in the second accommodation cavity 2412.

[0064] In the above embodiment, the first magnetic device 242 and the second magnetic device 243 are centrally arranged in the heat dissipation shell 241, and the gap between the first magnetic device 242 and the inner wall of the first accommodating cavity 2411 and the gap between the second magnetic device 243 and the inner wall of the second accommodating cavity 2412 can be filled with potting glue, so as to fix the first magnetic device 242 and the second magnetic device 243 in the heat dissipation shell 241. In addition, the first accommodating cavity 2411 and the second accommodating cavity 2412 are separated by the barrier wall 2414, so as to reduce the thermal coupling between the first magnetic device 242 and the second magnetic device 243, and the amount of potting glue can be reduced, thereby reducing the cost. The integrated magnetic device 24 of the present application can realize the integrated layout of the magnetic device on one hand, and can realize the integrated heat dissipation of the magnetic device on the other hand, so as to improve the loss density of the magnetic device inside the power conversion device 20, thereby reducing the loss of the power conversion device 20.

[0065] In the above embodiment, the thermal conductivity of the potting glue is greater than that of the barrier wall 2414. The potting glue can not only fix the magnetic device in the heat dissipation shell 241, but also transfer the heat of the magnetic device to the heat dissipation shell 241.

[0066] In addition, the barrier wall 2414 and the heat dissipation shell 241 can be made of different materials. Specifically, the thermal conductivity of the barrier wall 2414 can be less than that of the heat dissipation shell 241, so as to guide the heat of the magnetic device to the heat dissipation shell 241 and reduce the heat transfer between the magnetic devices of the adjacent two accommodating cavities. The barrier wall 2414 can be made of a material with low thermal conductivity, for example, a plastic part, so as to reduce the cost.

[0067] In some embodiments, the high heat loss region of the first magnetic device 242 is arranged in a direction away from the second receiving cavity 2412, and the high heat loss region of the second magnetic device 243 is arranged in a direction away from the first receiving cavity 2411. In this way, the low heat loss regions of the first magnetic device 242 and the second magnetic device 243 are placed close to the central position of the heat dissipation shell 241, and the high heat loss regions of the first magnetic device 242 and the second magnetic device 243 are placed close to the outer periphery of the heat dissipation shell 241, achieving a layout of low temperature aggregation and high temperature externalization, so that most of the heat of the first magnetic device 242 and the second magnetic device 243 can be directly transmitted through the heat dissipation shell 241 to reduce the thermal coupling between the first magnetic device 242 and the second magnetic device 243. For example, in an embodiment, the first magnetic device 242 can include a DC-DC transformer 2421 and a DC-DC inductor 2422, and the second magnetic device 243 includes an LLC transformer 2431 and an LLC inductor 2432. In actual application, if the heat loss of the inductor can be less than the heat loss of the transformer, the DC-DC inductor 2422 and the LLC inductor 2432 can be placed at the central position of the heat dissipation shell 241, and the DC-DC transformer 2421 and the LLC transformer 2431 are placed at the outer periphery position of the heat dissipation shell 241. If the heat loss of the inductor can be greater than the heat loss of the transformer, the DC-DC inductor 2422 and the LLC inductor 2432 can be placed at the outer periphery position of the heat dissipation shell 241, and the DC-DC transformer 2421 and the LLC transformer 2431 are placed at the central position of the heat dissipation shell 241.

[0068] In the embodiments of the present application, the specific number of the plurality of magnetic devices of the power conversion device 20 is not limited, and the heat dissipation shell 241 can correspond to these magnetic devices to arrange receiving cavities, so that these magnetic devices are placed independently in a single receiving cavity, thereby isolating these magnetic devices from each other.

[0069] The specific structure of the power conversion device 20 is described below with OBC as an example. FIG. 6 is another schematic view of the integrated magnetic device provided in the embodiment of the present application, FIG. 7 is an exploded schematic view of the integrated magnetic device provided in the embodiment of the present application, FIG. 8 is a schematic view of the heat dissipation shell provided in the embodiment of the present application, and FIG. 9 is a layout schematic view of the first magnetic device, the second magnetic device, and the third magnetic device provided in the embodiment of the present application. As shown in FIGS. 6 to 9, the plurality of accommodation cavities can include a first accommodation cavity 2411, a second accommodation cavity 2412, and a third accommodation cavity 2413. The first accommodation cavity 2411, the second accommodation cavity 2412, and the third accommodation cavity 2413 are arranged adjacently in pairs. The plurality of magnetic devices include a first magnetic device 242, a second magnetic device 243, and a third magnetic device 244. The first magnetic device 242 is accommodated in the first accommodation cavity 2411, the second magnetic device 243 is accommodated in the second accommodation cavity 2412, and the third magnetic device 244 is accommodated in the third accommodation cavity 2413. Specifically, in the OBC, the first magnetic device 242 can include a DC-DC transformer 2421 and a DC-DC inductor 2422, the second magnetic device 243 includes an LLC transformer 2431 and an LLC inductor 2432, and the third magnetic device 244 includes a PFC magnetic device. The plurality of magnetic devices of the OBC are placed centrally to realize the integrated layout and integrated heat dissipation of the magnetic devices.

[0070] It should be noted that the three magnetic devices and the three accommodation cavities in the embodiment are only for illustrating the structure of the OBC, and the number of magnetic devices and the number of accommodation cavities are not limited to only three. When the heat dissipation shell 241 accommodates the magnetic devices of the MCU, the DC-DC converter, and / or the PDU, the specific number of the accommodation cavities is set according to the number of the magnetic devices to be placed.

[0071] As shown in FIG. 7, the barrier wall 2414 can be integrally formed with the heat dissipation shell 241, so that the heat of the magnetic devices can be transferred to the heat dissipation shell 241 through the barrier wall 2414, thereby increasing the heat dissipation area. FIG. 10 is another exploded schematic view of the integrated magnetic device provided in the embodiment of the present application. As shown in FIG. 10, the barrier wall 2414 can also be detachably connected with the heat dissipation shell 241.

[0072] Fig. 11 is a sectional view of the heat dissipation shell and the third magnetic device along the direction of A-A in Fig. 8, and Fig. 12 is a sectional view of the heat dissipation shell and the second magnetic device along the direction of B-B in Fig. 8. As shown in Figs. 11 and 12, in some embodiments, the inner wall of at least one of the plurality of accommodating cavities is provided with at least one heat dissipation protrusion 2415. One of the at least one heat dissipation protrusion 2415 corresponds to a recess of the magnetic device, so as to shorten the heat conduction path between the recess and the inner wall, make the heat conduction path between the outer surface of the magnetic device and the inner wall more uniform, and thus reduce the heat conduction path between the magnetic device and the heat dissipation shell 241, so as to reduce the heat dissipation thermal resistance, while the amount of potting glue can be reduced, thereby reducing the cost.

[0073] In the plurality of accommodating cavities, the distance between the surface of the magnetic device in each accommodating cavity and the inner wall of each accommodating cavity is less than or equal to a set threshold, so as to reduce the heat conduction path between the magnetic device and the heat dissipation shell 241, reduce the heat dissipation thermal resistance, while the amount of potting glue can be reduced, thereby reducing the cost. In a specific embodiment, the set threshold can be set to 4 mm, i.e., the distance between the surface of the magnetic device and the inner wall of the corresponding accommodating cavity is less than or equal to 4 mm.

[0074] Fig. 13 is another exploded view of the heat dissipation shell and the magnetic device provided by the embodiments of the present application. As shown in Fig. 13, in an embodiment, the inner wall of at least one of the plurality of accommodating cavities is provided with a plurality of heat dissipation teeth 2416, and the plurality of heat dissipation teeth 2416 are arranged in an array. The plurality of heat dissipation teeth 2416 can increase the heat dissipation area between the heat dissipation shell 241 and the magnetic device, and further improve the heat dissipation efficiency. In the present application, the shape of the heat dissipation teeth 2416 is not specifically limited, for example, the shape of the heat dissipation teeth 2416 can be cylindrical, conical or other irregular shapes.

[0075] In the present application, the heat dissipation of the three magnetic devices is different, and the temperature of each magnetic device is also different when the power conversion device 20 is working. Specifically, in the OBC, the heat dissipation of the DC-DC transformer 2421 can be less than the heat dissipation of the DC-DC inductor 2422. Fig. 14 is another layout view of the first magnetic device, the second magnetic device and the third magnetic device provided by the embodiments of the present application. As shown in Figs. 9 and 14, the DC-DC transformer 2421 is placed adjacent to the second accommodating cavity 2412 and adjacent to the third accommodating cavity 2413. In the first accommodating cavity 2411, the DC-DC transformer 2421 with lower heat dissipation is placed close to the center position of the heat dissipation shell 241, and the DC-DC inductor 2422 with higher heat dissipation is placed close to the outer periphery of the heat dissipation shell 241, so as to realize the layout of low-temperature aggregation and high-temperature externalization, and enable most of the heat of the DC-DC inductor 2422 to be directly transmitted through the heat dissipation shell 241, so as to reduce the thermal coupling between the magnetic devices.

[0076] Similarly, the heat loss of the LLC transformer 2431 can be less than the heat loss of the LLC inductor 2432. FIG. 15 is another layout diagram of the first magnetic device, the second magnetic device and the third magnetic device according to an embodiment of the present application, and FIG. 16 is another layout diagram of the first magnetic device, the second magnetic device and the third magnetic device according to an embodiment of the present application. As shown in FIG. 9, FIG. 15 and FIG. 16, the LLC transformer 2431 is placed adjacent to the first receiving cavity 2411 and adjacent to the third receiving cavity 2413. In the second receiving cavity 2412, the LLC transformer 2431 with less heat loss is placed close to the center of the heat dissipation shell 241, and the LLC inductor 2432 with higher heat loss is placed close to the outer periphery of the heat dissipation shell 241, so as to realize the layout of low-temperature aggregation and high-temperature externalization, and enable most of the heat of the LLC inductor 2432 to be directly transmitted through the heat dissipation shell 241, so as to reduce the thermal coupling between the magnetic devices.

[0077] The above-mentioned layout of low-temperature aggregation and high-temperature externalization can improve the magnetic device loss density inside the power conversion device 20, so as to reduce the loss of the power conversion device 20, and further improve the charging efficiency of the power conversion device 20 to the power battery 11.

[0078] Of course, by adjusting the loss distribution of the magnetic devices, the temperature change of the transformer and the inductor can also be realized. FIG. 17 is another layout diagram of the first magnetic device, the second magnetic device and the third magnetic device according to an embodiment of the present application. As shown in FIG. 15, FIG. 16 and FIG. 17, the heat loss of the DC-DC inductor 2422 is less than the heat loss of the DC-DC transformer 2421. The DC-DC inductor 2422 is placed adjacent to the second receiving cavity 2412 and adjacent to the third receiving cavity 2413. As shown in FIG. 17, the heat loss of the LLC transformer 2431 can be greater than the heat loss of the LLC inductor 2432. The LLC inductor 2432 is placed adjacent to the first receiving cavity 2411 and adjacent to the third receiving cavity 2413.

[0079] As shown in FIG. 7, in one embodiment, the openings of the first receiving cavity 2411, the second receiving cavity 2412 and the third receiving cavity 2413 are oriented in the same direction, which can facilitate the installation and disassembly of the magnetic devices. Moreover, the first receiving cavity 2411, the second receiving cavity 2412 and the third receiving cavity 2413 are arranged in a triangular shape, which can realize the miniaturization of the heat dissipation shell 241. At this time, the barrier wall 2414 is in a T shape.

[0080] In another embodiment, the openings of at least two of the first receiving cavity 2411, the second receiving cavity 2412 and the third receiving cavity 2413 are oriented in different directions. In this embodiment, the heat dissipation shell 241 has different openings, so that the magnetic devices can be mounted and dismounted from different directions according to the actual application scenario. FIG. 18 is another layout schematic diagram of the first magnetic device, the second magnetic device and the third magnetic device provided in the embodiment of the present application. As shown in FIG. 18, the heat dissipation shell 241 can be opened from two opposite positions. Among them, the opening direction of the first receiving cavity 2411 is the same as that of the third receiving cavity 2413, and the opening direction of the second receiving cavity 2412 is opposite to that of the first receiving cavity 2411. In this embodiment, the second magnetic device 243 can be located above the first magnetic device 242 and the third magnetic device 244.

[0081] FIG. 19 is another schematic diagram of the power conversion device provided in the embodiment of the present application. As shown in FIG. 19, the shell 21 of the power conversion device 20 includes a bottom shell 211 and a cover plate 212, the cover plate 212 covers the bottom shell 211 and forms an accommodation space, the circuit board 22, the power module 23 and the integrated magnetic device 24 are located in the accommodation space. In addition, the shell 21 further includes oppositely arranged first cooling plate 213 and second cooling plate 214, the first cooling plate 213 is provided with a first cooling flow channel, and the second cooling plate 214 is provided with a second cooling flow channel. In one embodiment, the circuit board 22 is located between the first cooling plate 213 and the second cooling plate 214. The power module 23 is located between the second cooling plate 214 and the circuit board 22, and the integrated magnetic device 24 is located between the first cooling plate 213 and the circuit board 22. In this embodiment, the integrated magnetic device 24 can be cooled by the first cooling plate 213, and the power module 23 can be cooled by the second cooling plate 214, so as to transfer the heat in the power conversion device 20 to the outside.

[0082] Of course, the integrated magnetic device 24 can be cooled by multiple cooling plates to increase the heat dissipation efficiency. FIG. 20 is another schematic diagram of the power conversion device provided in the embodiment of the present application. As shown in FIG. 20, in another embodiment, the circuit board 22 is located on the side of the second cooling plate 214 away from the first cooling plate 213. The power module 23 is located between the circuit board 22 and the second cooling plate 214, and the integrated magnetic device 24 is located between the first cooling plate 213 and the second cooling plate 214. Therefore, the integrated magnetic device 24 can be cooled by the first cooling plate 213 and the second cooling plate 214.

[0083] In one embodiment, the first cooling plate 213 can be a part of the housing 21 of the power conversion device 20. Specifically, the bottom shell 211 includes the first cooling plate 213 and a plurality of side plates. The cover plate 212 is disposed opposite to the first cooling plate 213. The aforementioned plurality of side plates are sequentially connected and located between the cover plate 212 and the first cooling plate 213. The cover plate 212, the aforementioned plurality of side plates and the first cooling plate 213 enclose the housing 21 of the power conversion device 20, and the circuit board 22, the power module 23, the integrated magnetic device 24 and the second cooling plate 214 are located in the housing 21. The second cooling plate 214 is located between the integrated magnetic device 24 and the cover plate 212, and the heat dissipation shell 241 is fixedly connected to a side surface of the first cooling plate 213 facing the cover plate 212. In this embodiment, further, the heat dissipation shell 241 can also be detachably connected to the first cooling plate 213, so that the integrated magnetic device 24 can be integrally detached for maintenance or replacement.

[0084] As shown in FIGS. 19 and 20, in one embodiment, a heat-conducting pad 215 is provided between the heat dissipation shell 241 and the first cooling plate 213, and the heat-conducting coefficient of the heat-conducting pad 215 is greater than that of the barrier wall 2414. The heat of the heat dissipation shell 241 is transmitted to the housing 21 through the heat-conducting pad 215, thereby increasing the heat dissipation rate.

[0085] In another embodiment, the first cooling plate 213 can also be independently provided relative to the housing 21 of the power conversion device 20. The circuit board 22, the power module 23, the integrated magnetic device 24 and the second cooling plate 214 are located in the bottom shell 211. The heat dissipation shell 241 is an integral structure with the bottom shell 211. The first cooling plate 213 is fixedly connected to a side of the bottom shell 211 away from the cover plate 212, and the second cooling plate 214 is located between the integrated magnetic device 24 and the cover plate 212. In this embodiment, further, the heat dissipation shell 241 can also be an integral structure with the bottom shell 211, i.e., the bottom plate of the heat dissipation shell 241 can be a part of the bottom shell 211, so that the height dimension of the power conversion device 20 can be reduced.

[0086] In some embodiments, at least one of the plurality of accommodation cavities includes a through hole on the side of the first cooling plate 213, and the magnetic device part of the at least one accommodation cavity extends out of the through hole. FIG. 21 is another schematic view of the heat dissipation shell according to an embodiment of the present application. As shown in FIG. 21, the first accommodation cavity 2411 is provided with a first through hole 2417 on the side of the first cooling plate 213, and the first magnetic device 242 extends out of the first through hole 2417. Similarly, the second accommodation cavity 2412 is provided with a second through hole 2418 on the side of the first cooling plate 213, and the second magnetic device 243 extends out of the second through hole 2418. Similarly, the third accommodation cavity 2413 is provided with a third through hole 2419 on the side of the first cooling plate 213, and the third magnetic device 244 extends out of the third through hole 2419. The magnetic device extends out of the heat dissipation shell 241, which can shorten the heat conduction distance between the magnetic device and the cooling flow channel, thereby reducing the heat dissipation thermal resistance, and the material usage of the heat dissipation shell 241 is reduced, which can reduce the cost.

[0087] FIG. 22 is another schematic view of the power conversion device according to an embodiment of the present application. As shown in FIG. 22, the power conversion device 20 further includes a DC-DC converter 25 and a PDU 26 located in the shell 21, and the DC-DC converter 25 and the PDU 26 are respectively located on the side of the integrated magnetic device 24. The power conversion device 20 in this embodiment can integrate the OBC, the DC-DC converter 25 and the PDU 26, which is conducive to the integration and light weight of the power assembly 12. The dashed box in FIG. 22 can be used to illustrate the OBC.

[0088] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A power conversion device, characterized by, The power conversion device comprises a circuit board, a power module and an integrated magnetic device, the integrated magnetic device and the power module are electrically connected with the circuit board respectively, and the power module and the circuit board are arranged on the same side of the integrated magnetic device. The integrated magnetic device comprises a heat dissipation shell and a plurality of magnetic devices; the heat dissipation shell is provided with a barrier wall, the barrier wall divides the internal space of the heat dissipation shell into a plurality of accommodation cavities; the plurality of accommodation cavities at least comprises a first accommodation cavity and a second accommodation cavity arranged adjacently. The plurality of magnetic devices at least comprises a first magnetic device and a second magnetic device; the first magnetic device is placed in the first accommodation cavity, and the second magnetic device is placed in the second accommodation cavity.

2. The power conversion device of claim 1, wherein, The thermal conductivity coefficient of the barrier wall is less than the thermal conductivity coefficient of the heat dissipation shell.

3. A power conversion device as claimed in claim 1 or 2, characterized in that At least one heat dissipation protrusion is arranged on the inner wall of the plurality of accommodation cavities, and one heat dissipation protrusion of the at least one heat dissipation protrusion corresponds to a recess of the first magnetic device or the second magnetic device.

4. The power conversion device of any one of claims 1 to 3, wherein, In the plurality of accommodation cavities, the distance between the surface of the magnetic device in each accommodation cavity and the inner wall of each accommodation cavity is less than or equal to a set threshold value.

5. The power conversion device of any one of claims 1 to 4, wherein, The inner wall of the plurality of accommodation cavities is provided with a plurality of heat dissipation teeth, and the plurality of heat dissipation teeth are arranged in an array.

6. The power conversion device of any one of claims 1 to 5, wherein, The high heat loss area of the first magnetic device is arranged in a direction away from the second accommodation cavity, and the high heat loss area of the second magnetic device is arranged in a direction away from the first accommodation cavity.

7. The power conversion device of any one of claims 1 to 6, wherein, The first magnetic device comprises a DC-DC transformer and a DC-DC inductor, and the second magnetic device comprises an LLC transformer and an LLC inductor.

8. The power conversion device of claim 7, wherein, The heat loss of the DC-DC transformer is less than the heat loss of the DC-DC inductor, the DC-DC transformer is arranged in a direction close to the second accommodation cavity, and the DC-DC inductor is located on the side of the DC-DC transformer away from the second accommodation cavity. The heat loss of the LLC transformer is less than the heat loss of the LLC inductor, the LLC transformer is placed in a direction close to the first accommodation cavity, and the LLC inductor is located on the side of the LLC transformer away from the first accommodation cavity.

9. A power conversion device as claimed in claim 7 or 8, characterised in that, The power conversion device further comprises a DC-DC converter and a power distribution unit, and the DC-DC converter and the power distribution unit are respectively located on the circumferential side of the integrated magnetic device.

10. The power conversion device of any one of claims 1 to 9, wherein, The power conversion device further comprises a first cooling plate and a second cooling plate arranged oppositely. The first cooling plate is provided with a first cooling flow channel, and the second cooling plate is provided with a second cooling flow channel; the circuit board is located between the first cooling plate and the second cooling plate; the power module is located between the second cooling plate and the circuit board, and the integrated magnetic device is located between the first cooling plate and the circuit board.

11. The power conversion device of any one of claims 1 to 9, wherein, The power conversion device further comprises a first cooling plate and a second cooling plate arranged oppositely. The first cooling plate is provided with a first cooling flow channel, and the second cooling plate is provided with a second cooling flow channel; the circuit board is located on the side of the second cooling plate away from the first cooling plate; the power module is located between the circuit board and the second cooling plate, and the integrated magnetic device is located between the first cooling plate and the second cooling plate.

12. A power conversion device as claimed in claim 10 or 11, characterised in that, The power conversion device further comprises a cover plate and a plurality of side plates, the cover plate is arranged opposite to the first cooling plate, and the plurality of side plates are sequentially connected and located between the cover plate and the first cooling plate; the cover plate, the plurality of side plates and the first cooling plate enclose a shell of the power conversion device, and the circuit board, the power module, the integrated magnetic device and the second cooling plate are located in the shell; the second cooling plate is located between the integrated magnetic device and the cover plate, and the heat dissipation shell is fixedly connected to one side surface of the first cooling plate facing the cover plate.

13. The power conversion device of claim 12, wherein, A heat-conducting pad is arranged between the heat dissipation shell and the first cooling plate, and a thermal conductivity of the heat-conducting pad is greater than that of the barrier wall.

14. The power conversion device of claim 10 or 11, wherein, The power conversion device further comprises a bottom shell and a cover plate, the cover plate covers the bottom shell; the circuit board, the power module, the integrated magnetic device and the second cooling plate are located in the bottom shell; the heat dissipation shell and the bottom shell are an integral structure; the first cooling plate is fixedly connected to one side of the bottom shell away from the cover plate, and the second cooling plate is located between the integrated magnetic device and the cover plate.

15. The power conversion device of any one of claims 10 to 11, wherein, At least one of the plurality of accommodation cavities comprises a through hole on one side of the first cooling plate, and a magnetic device in the at least one accommodation cavity partially extends out of the through hole.

16. The power conversion device of any one of claims 7 to 12, wherein, The plurality of accommodation cavities further comprise a third accommodation cavity, the first accommodation cavity and the second accommodation cavity are arranged adjacent to the third accommodation cavity respectively; the plurality of magnetic devices further comprise a third magnetic device; the third accommodation cavity is used for accommodating the third magnetic device, and the third magnetic device is a PFC magnetic device.

17. The power conversion device of claim 16, wherein, The openings of the first accommodation cavity, the second accommodation cavity and the third accommodation cavity are oriented in the same direction, and the first accommodation cavity, the second accommodation cavity and the third accommodation cavity are arranged in a triangular shape; or The openings of at least two of the first accommodation cavity, the second accommodation cavity and the third accommodation cavity are oriented in different directions.

18. The power conversion device of any one of claims 1 to 17, wherein, The first accommodation cavity and the first magnetic device, and the second accommodation cavity and the second magnetic device are respectively filled with potting glue, and a thermal conductivity of the potting glue is greater than that of the barrier wall.

19. A powertrain, characterized by, The power conversion device comprises a motor, a reducer and a power conversion device as claimed in any one of claims 1 to 18, the motor is connected to the power conversion device, and the motor is connected to the reducer.

20. An electric vehicle characterized by comprising: The power assembly comprises a power battery and a power assembly as claimed in claim 19, the power conversion device of the power assembly is used for charging the power battery, and the power battery is used for providing direct current to the power assembly.

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