Power converter and charging equipment

Abstract

The embodiment of the utility model relates to the technical field of charging, in particular to a power converter and charging equipment. The utility model aims to solve the problem that the heat dissipation performance of a magnetic device is affected due to serious heat accumulation in the magnetic core and higher temperature rise. The embodiment of the utility model provides a power converter. The power converter comprises a first magnetic core and a second magnetic core. The first magnetic core comprises a first middle column, the first middle column comprises a first end and a first core part, and first air gaps are formed between the first core part and the first end and between the first core part and the first magnetic core body. The second magnetic core comprises a second middle column, the second middle column comprises a second end and a second core part, second air gaps are formed between the second core part and the second end and between the second core part and the second magnetic core body, heat of the first air gap can be transmitted to the outside of the magnetic core through the first middle column, and heat of the second air gap can be transmitted to the outside of the magnetic core through the second middle column. The heat transmission distance of the first air gap and the second air gap is shortened, serious heat accumulation in the magnetic core is avoided, the temperature rise of the magnetic core is reduced, and the performance of a magnetic device is guaranteed.

Description

TECHNICAL FIELD

[0001] The embodiment of the present application relates to the technical field of charging, in particular to a power converter and a charging device. BACKGROUND

[0002] The power converter comprises a magnetic device, and the magnetic device comprises a magnetic core and a winding coil. In order to reduce the excitation inductance, a plurality of air gaps are usually arranged on the center column of the magnetic core. However, the magnetic core is prone to heat when the magnetic device is working, the heat transfer distance of the heat at the air gap to the outside of the magnetic core is far, and the heat accumulation in the magnetic core is prone to be serious, the temperature rise is high, and the performance of the magnetic device is affected. CONTENT OF THE UTILITY MODEL

[0003] The embodiment of the present application provides a power converter and a charging device, which can avoid the serious heat accumulation in the magnetic core, reduce the temperature rise of the magnetic core, and ensure the performance of the magnetic device.

[0004] In a first aspect, the embodiment of the present application provides a power converter, comprising a circuit board and a magnetic device. The magnetic device comprises a first magnetic core, a second magnetic core and a winding coil. The first magnetic core comprises a first magnetic core body and a first center column arranged on the first magnetic core body. The first center column comprises a first end portion and a first core portion, the first core portion is located between the first end portion and the first magnetic core body, and the first core portion has a first air gap between the first end portion and the first magnetic core body. The second magnetic core comprises a second magnetic core body and a second center column arranged on the second magnetic core body. The second center column comprises a second end portion and a second core portion, the second core portion is located between the second end portion and the second magnetic core body, and the second core portion has a second air gap between the second end portion and the second magnetic core body. Wherein, the first center column and the second center column are located between the first magnetic core body and the second magnetic core body, and the center line of the first center column and the center line of the second center column are collinear. The winding coil is wound on the first center column and the second center column.

[0005] The first core portion has a first air gap between the first end portion and the first magnetic core body, and the second core portion has a second air gap between the second end portion and the second magnetic core body. The heat of the first air gap can be transmitted to the outside of the magnetic core through the first center column, and the heat of the second air gap can be transmitted to the outside of the magnetic core through the second center column. The heat transfer distance of the first air gap and the second air gap is shortened, the heat accumulation in the magnetic core is avoided, the temperature rise of the magnetic core is reduced, and the performance of the magnetic device is ensured.

[0006] Meanwhile, the air gaps are located on the first center column and the second center column respectively, the distribution of the air gaps on the center column is more uniform, the temperature distribution of the center column is more uniform, the heat dissipation efficiency of the magnetic core can be improved, and the normal use of the magnetic device is ensured.

[0007] In some embodiments that can include some of the above-mentioned embodiments, along the centerline direction of the first limb, the distance between the first end portion close to one end of the first core portion and the first magnetic core body is less than the length of the first end portion. Along the centerline direction of the second limb, the distance between the second end portion close to one end of the second core portion and the second magnetic core body is less than the length of the second end portion.

[0008] The first air gap is closer to the first magnetic core body and farther away from the first end portion, the second air gap is closer to the second magnetic core body and farther away from the second end portion, that is, the air gap is located on both sides of the limb and closer to the magnetic core body, so that the first air gap and the second air gap are shorter in distance for heat transfer to the outside of the magnetic core, which can improve the heat dissipation rate of the first air gap and the second air gap, thereby improving the heat dissipation rate of the magnetic core.

[0009] In some embodiments that can include some of the above-mentioned embodiments, along the centerline direction of the first limb, the length of the first air gap is less than or equal to 1mm. Along the centerline direction of the second limb, the length of the second air gap is less than or equal to 1mm.

[0010] Along the centerline direction of the first limb, the length of the first air gap is less than or equal to 1mm, and along the centerline direction of the second limb, the length of the second air gap is less than or equal to 1mm, which can ensure that the excitation inductance of the power converter is small while avoiding overheating at the air gap.

[0011] In some embodiments that can include some of the above-mentioned embodiments, the first limb further comprises a first root portion between the first core portion and the first magnetic core body, and the second limb further comprises a second root portion between the second core portion and the second magnetic core body. The first root portion and the first magnetic core body are in an integrated structure, and the second root portion and the second magnetic core body are in an integrated structure.

[0012] The first root portion and the first magnetic core body are in an integrated structure, which facilitates the bonding of the first core portion and the first end portion to the first magnetic core body and can limit the position of the first limb. At the same time, there is no air gap between the first root portion and the first magnetic core body, which can avoid the air gap being located at the edge of the first limb and causing excessive magnetic flux leakage.

[0013] The second root portion and the second magnetic core body are in an integrated structure, which facilitates the bonding of the second core portion and the second end portion to the second magnetic core body and can limit the position of the second limb. At the same time, there is no air gap between the second root portion and the second magnetic core body, which can avoid the air gap being located at the edge of the second limb and causing excessive magnetic flux leakage.

[0014] In some embodiments that can include some of the above-mentioned embodiments, the number of first core portions is multiple, and the multiple first core portions are arranged along the center line of the first limb. The number of second core portions is multiple, and the multiple second core portions are arranged along the center line of the second limb. There is a fourth air gap between two adjacent first core portions, and a fifth air gap between two adjacent second core portions.

[0015] The number of first core portions and second core portions is multiple, which can increase the number of air gaps on the first limb and the second limb, so that the permeability of the magnetic core becomes smaller and the magnetic resistance becomes larger. By adjusting the number of first core portions and second core portions, the permeability of the magnetic device can be adjusted to meet the requirements of the power converter.

[0016] In some embodiments that can include some of the above-mentioned embodiments, a first heat-conducting sheet is arranged in the first air gap, and a second heat-conducting sheet is arranged in the second air gap. A fourth heat-conducting sheet is arranged in the fourth air gap, and a fifth heat-conducting sheet is arranged in the fifth air gap.

[0017] The heat-conducting sheet has a large thermal conductivity and a fast heat transfer speed, which can improve the heat dissipation rate at the first air gap, the second air gap, the fourth air gap, and the fifth air gap, thereby improving the heat dissipation rate of the magnetic core.

[0018] In some embodiments that can include some of the above-mentioned embodiments, the first heat-conducting sheet, the second heat-conducting sheet, the fourth heat-conducting sheet, and the fifth heat-conducting sheet are ceramic sheets or epoxy boards.

[0019] The ceramic sheet and the epoxy board do not conduct magnetism and do not affect the magnetic field. The use of ceramic sheets or epoxy boards for the first heat-conducting sheet, the second heat-conducting sheet, the fourth heat-conducting sheet, and the fifth heat-conducting sheet does not affect the influence of the air gap on the magnetic core, while improving the heat transfer rate at the air gap.

[0020] In some embodiments that can include some of the above-mentioned embodiments, there is a third air gap between the first end portion and the second end portion.

[0021] The third air gap can provide space for the deformation of the first limb and the second limb, avoiding cracking when the first limb and the second limb deform due to thermal expansion and contraction.

[0022] In some embodiments that can include some of the above-mentioned embodiments, the length of the third air gap in the direction of the center line of the first limb is 0.2mm-1mm.

[0023] The third air gap can provide space for the deformation of the magnetic core, while avoiding the third air gap being too large, which can cause serious magnetic leakage at the third air gap and a temperature that is too high at the third air gap.

[0024] In some embodiments that can include some of the above-mentioned embodiments, a soft heat-conducting glue is arranged in the third air gap.

[0025] Soft thermal conductive adhesive has high flexibility. It usually does not cure or is elastic after curing, and can change its shape to adapt to the deformation of the magnetic core. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of the charging device provided in the embodiments of this application;

[0027] Figure 2 This is a schematic diagram of the power converter provided in the embodiments of this application;

[0028] Figure 3 This is a schematic diagram of the structure of the magnetic device provided in the embodiments of this application;

[0029] Figure 4 A schematic diagram of the magnetic core provided in the embodiments of this application. Figure 1 ;

[0030] Figure 5 A schematic diagram of the magnetic core provided in the embodiments of this application. Figure 2 ;

[0031] Figure 6 for Figure 3 Sectional view along axis AA;

[0032] Figure 7 A schematic diagram of the magnetic core provided in the embodiments of this application. Figure 3 .

[0033] Explanation of reference numerals in the attached figures:

[0034] 10: Charging equipment; 11: Charging gun; 12: Electric vehicle; 13: Power grid; 20: Power converter; 21: Circuit board; 30: Magnetic device; 31: Winding coil; 40: Magnetic core; 41: First magnetic core; 41a: First magnetic core body; 41b: First side post; 42: Second magnetic core; 42a: Second magnetic core body; 42b: Second side post; 51: First central post; 51a: First end; 51b: First core; 51c: First root; 52: Second central post; 52a: Second end; 52b: Second core; 52c: Second root; 61: First air gap; 62: Second air gap; 63: Third air gap; 64: Fourth air gap; 65: Fifth air gap. Detailed Implementation

[0035] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will be combined with the accompanying drawings to make a clear and complete description of the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0036] Hereinafter, the terms "first", "second", and the like are only used for descriptive purposes, 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", and the like can explicitly or implicitly include one or more of the features.

[0037] In addition, in the embodiments of the present application, the orientation terms such as "upper", "lower", "left", "right", "horizontal" and "vertical" are defined with respect to the orientation of the components shown in the drawings. It should be understood that these directional terms are relative concepts, which are used for relative description and clarification, and can be changed accordingly according to the change of the orientation of the components placed in the drawings.

[0038] In the embodiments of the present application, unless otherwise explicitly specified and limited, the term "connection" should be understood in a broad sense, for example, "connection" can be fixed connection, electrical connection, or detachable connection, or integral; can be directly connected, or indirectly connected through an intermediate medium.

[0039] Please refer to Figure 1 The embodiments of the present application provide a charging device 10, which includes a charging gun 11 and a power converter 20. The power converter 20 is used to output the input power after power conversion to the charging gun 11. The charging gun 11 is used to connect an electric vehicle 12.

[0040] The embodiments of the present application do not limit the charging device 10. For example, the charging device 10 can include a charging pile, a charging pile, etc. The embodiments of the present application do not limit the power converter 20. For example, the power converter 20 can include a blade power supply, an on-board charger (OBC for short), etc.

[0041] In the embodiment in which the charging device 10 includes a charging pile, the power converter 20 can include an alternating current-direct current (AC-DC for short) module and a DC-DC module. The input end of the AC-DC module is connected to the power grid 13, and the output end is connected to the DC bus. The input end of the DC-DC module is connected to the DC bus, and the output end of the DC-DC module is connected to the input end of the power distribution module.

[0042] The charging device 10 receives alternating current from the power grid 13 or other external power source through the cable and transmits the alternating current to the AC-DC module, which can convert the alternating current into direct current and output to the DC bus. The DC-DC module further converts the direct current obtained from the DC bus into direct current suitable for the electric vehicle 12 and outputs to the power distribution module. The power distribution module dynamically distributes the direct current output by the DC-DC module according to the actual charging power required by the electric vehicle 12, and delivers the distributed charging power to the electric vehicle 12 through the charging gun 11.

[0043] The charging device 10 also includes a housing, a human-computer interaction interface, a charging controller, a metering and billing device, and the like, for information interaction, energy transmission, and metering and billing with the electric vehicle 12.

[0044] The electric vehicle 12 is a kind of transportation tool driven by electric energy. The electric vehicle 12 can include a pure electric vehicle (pure EV / battery EV), a hybrid electric vehicle (HEV), a range extended electric vehicle (REEV), and a plug-in hybrid electric vehicle (PHEV), etc.

[0045] The charging device 10 also includes a cooling structure in thermal contact with the power converter 20. It can be understood that the cooling structure can be arranged inside the power converter 20, and can also be arranged outside the power converter 20 in contact with the housing of the power converter 20. The embodiments of the present application do not limit the cooling structure, which can include a forced air cooling structure and a liquid cooling structure, for example.

[0046] In the embodiment in which the cooling structure includes a forced air cooling structure, the cooling structure can include a fan and a heat sink inside the power converter 20. The heat sink can be in contact with the power converter 20, and the fan is used to drive air to flow through the heat sink to cool the heat sink, thereby cooling the power converter 20.

[0047] In the embodiment where the cooling structure comprises a liquid cooling structure, the cooling structure can comprise a liquid cooling plate and a cover plate, the liquid cooling plate comprising one long plate and two short plates, the long plate and the short plates forming a groove, the cooling liquid being arranged in the groove, and the cover plate being arranged on the cooling plate to seal the cooling liquid in the groove formed by the cooling plate. The cooling structure further comprises a cooling pump, a cooling pipe and a fan, the cooling pump being arranged on the cooling pipe, the cooling liquid being arranged in the cooling pipe, and the fan being arranged on the side of the cooling pipe away from the power converter 20.

[0048] The cooling pump can make the cooling liquid continuously flow in a specified direction inside the cooling pipe. When the cooling liquid flows close to the power converter 20, the heat of the power converter 20 can be transmitted to the cooling liquid through the liquid cooling plate, and the cooling liquid carrying the heat continues to flow. On the side away from the power converter 20, the heat of the cooling liquid is transmitted to the cooling pipe and the temperature of the cooling liquid is restored, and the cooling liquid continues to be used for heat dissipation of the power converter 20. The fan can drive air to flow through the cooling pipe, so that the temperature of the cooling pipe is reduced.

[0049] The power converter 20 can realize conversion of voltage or current. For example, the power converter 20 can convert alternating current into direct current, or convert alternating current into alternating current of another value, or convert direct current into direct current of another value. The embodiment of the present application does not limit the power converter 20, and for example, the power converter 20 can comprise a resonant converter, a rectifier, an inverter, etc.

[0050] Please refer to Figure 2 , the power converter 20 can comprise a circuit board 21 and a magnetic device 30, the magnetic device 30 being arranged on the circuit board 21 and being electrically connected to other devices on the circuit board 21. The embodiment of the present application does not limit the magnetic device 30, and for example, the magnetic device 30 can comprise a transformer or an inductor.

[0051] In the embodiment where the power converter 20 comprises a resonant converter and the magnetic device 30 comprises a transformer, the transformer can change the voltage level to realize the increase or decrease of the voltage. In the embodiment where the power converter 20 comprises a resonant converter and the magnetic device 30 comprises an inductor, the inductor can store energy and participate in resonance.

[0052] Please refer to Figure 3 , the magnetic device 30 comprises a magnetic core 40 and a winding coil 31, the winding coil 31 being arranged on the magnetic core 40. The current passing through the winding coil 31 can generate a magnetic field, and the magnetic field can cause electromagnetic induction of the winding coil 31 to generate a current in the winding coil 31, and the current is transmitted to other devices on the circuit board 21 through the circuit.

[0053] It can be understood that the power converter 20 can realize the conversion of the voltage, the larger the voltage regulation range is, the smaller the excitation inductance is. The smaller the magnetic permeability of the magnetic core 40 is, the larger the magnetic resistance is, and the smaller the excitation inductance is. The magnetic core 40 can be provided with an air gap on the center column, so as to reduce the magnetic permeability of the magnetic core 40, increase the magnetic resistance, realize the reduction of the excitation inductance, and thus ensure that the voltage regulation range of the power converter 20 is large.

[0054] Please refer to Figure 3 and Figure 4 , the embodiment of the application provides a magnetic core 40, which comprises a first magnetic core 41 and a second magnetic core 42. The embodiment of the application does not limit the magnetic core 40, and the magnetic core 40 can be a ferrite magnetic core, for example. The first magnetic core 41 comprises a first magnetic core body 41a and a first center column 51 provided on the first magnetic core body 41a. The first magnetic core body 41a can comprise two first side columns 41b, which are arranged at intervals and connected at the ends away from the second magnetic core 42, and the first center column 51 is located between and connected to the two first side columns 41b.

[0055] The embodiment of the application does not limit the shape of the center column and the side column, Figure 3 and Figure 4 two different shapes of the center column and the side column are exemplified.

[0056] Continuing to refer to Figure 3 and Figure 5 , the first center column 51 comprises a first end portion 51a and a first core portion 51b, the first core portion 51b being located between the first end portion 51a and the first magnetic core body 41a, and the first core portion 51b having a first air gap 61 between the first end portion 51a and the first magnetic core body 41a.

[0057] The second magnetic core 42 comprises a second magnetic core body 42a and a second center column 52 provided on the second magnetic core body 42a. Similarly to the first magnetic core 41, the second magnetic core body 42a comprises two second side columns 42b arranged at intervals and connected at the ends away from the first magnetic core 41, and the second center column 52 is located between and connected to the two second side columns 42b.

[0058] The second center column 52 comprises a second end portion 52a and a second core portion 52b, the second core portion 52b being located between the second end portion 52a and the second magnetic core body 42a, and the second core portion 52b having a second air gap 62 between the second end portion 52a and the second magnetic core body 42a.

[0059] Among them, the first center column 51 and the second center column 52 are located between the first magnetic core body 41a and the second magnetic core body 42a, and the center line of the first center column 51 and the center line of the second center column 52 are collinearFigure 3 and Figure 5 The center line of the first limb 51 and the center line of the second limb 52 are collinear, so as to ensure that the first limb and the second limb are aligned and constitute the limbs of the magnetic core, and ensure uniform distribution of the magnetic flux.

[0060] It can be understood that the center line of the first limb 51 and the center line of the second limb 52 are collinear, so as to ensure that the first limb and the second limb are aligned and constitute the limbs of the magnetic core, and ensure uniform distribution of the magnetic flux.

[0061] The first core portion 51b has a first air gap 61 between the first core portion 51b and the first end portion 51a and the first magnetic core body 41a, and the second core portion 52b has a second air gap 62 between the second core portion 52b and the second end portion 52a and the second magnetic core body 42a. The heat of the first air gap 61 can be transmitted to the outside of the magnetic core 40 through the first limb 51, and the heat of the second air gap 62 can be transmitted to the outside of the magnetic core 40 through the second limb 52.

[0062] Since the magnetic core 40 is in thermal conduction connection with the cooling structure, the heat at the air gap needs to be transmitted to the magnetic core 40 through the limb. The greater the distance between the air gap and the magnetic core body, the greater the heat transmission distance at the air gap, which will reduce the heat dissipation rate of the air gap, thereby affecting the performance of the magnetic device 30. Compared with the case where the first air gap 61 and the second air gap 62 are arranged on the same limb, the heat transmission distance of the first air gap 61 and the second air gap 62 (the heat transmission distance from the vicinity of the first air gap 61 to the first magnetic core body 41a, and the heat transmission distance from the vicinity of the second air gap 62 to the second magnetic core body 42a) is shortened, the heat accumulation in the magnetic core 40 is avoided, the temperature rise (the temperature of the magnetic core 40 is higher than the ambient temperature) of the magnetic core 40 is reduced, and the performance of the magnetic device 30 is ensured.

[0063] At the same time, the air gap is arranged on the first limb 51 and the second limb 52 respectively, so that the air gap is more uniformly distributed on the limb, the temperature distribution of the limb is more uniform, the heat dissipation efficiency of the magnetic core 40 can be improved, and the normal use of the magnetic device 30 is ensured.

[0064] In addition to arranging the first air gap 61 and the second air gap 62 on the first limb 51 and the second limb 52, air gaps can also be arranged on the first side limb 41b and the second side limb 42b respectively, so as to reduce the magnetic permeability of the magnetic core 40, improve the voltage regulation range of the power converter 20 (as shown in Figure 2 At the same time, the air gap is arranged on the first limb 51 and the second limb 52 respectively, so that the air gap is more uniformly distributed on the limb, the temperature distribution of the limb is more uniform, the heat dissipation efficiency of the magnetic core 40 can be improved, and the normal use of the magnetic device 30 is ensured.

[0065] Continuing to refer to Figure 5 and Figure 6 In the above embodiment, the first limb 51 and the second limb 52 are arranged in the center line direction of the first limb 51 and the center line direction of the second limb 52. Figure 5 and Figure 6In the direction of the dashed-dotted line), the distance L2 between the end of the first end portion 51a close to the first core portion 51b and the first magnetic core body 41a is smaller than the length L1 of the first end portion 51a. The distance between the end of the first end portion 51a close to the first core portion 51b and the first magnetic core body 41a includes the first air gap 61 between the first end portion 51a and the first core portion 51b, the first core portion 51b, and the first air gap 61 between the first core portion 51b and the first magnetic core body 41a.

[0066] At this time, the distance between the first air gap 61 farthest from the first magnetic core body 41a and the first magnetic core body 41a is still smaller than the distance between the first end portion 51a and the first air gap 61, that is, on the first center column 51, the distance between the first air gap 61 and the first end portion 51a is farther, the distance between the first air gap 61 and the first magnetic core body 41a is closer, and the distance of the first air gap 61 for transferring heat to the magnetic core 40 is shorter, which can improve the heat dissipation rate of the magnetic core 40.

[0067] In the direction of the center line of the second center column 52 ( Figure 5 And Figure 6 In the direction of the dashed-dotted line), the distance L4 between the end of the second end portion 52a close to the second core portion 52b and the second magnetic core body 42a is smaller than the length L3 of the second end portion 52a. The distance between the end of the second end portion 52a close to the second core portion 52b and the second magnetic core body 42a includes the second air gap 62 between the second end portion 52a and the second core portion 52b, the second core portion 52b, and the second air gap 62 between the second core portion 52b and the second magnetic core body 42a.

[0068] At this time, the distance between the second air gap 62 and the second magnetic core body 42a is closer, and the distance between the second air gap 62 and the second end portion 52a is farther, so that the distance of the second air gap 62 for transferring heat to the outside of the magnetic core 40 is shorter, which improves the heat dissipation rate of the magnetic core 40.

[0069] It can be understood that the air gap is located on both sides of the center column and closer to the body of the magnetic core 40, so that the distance of the air gap for transferring heat is shorter, which can improve the heat dissipation rate of the air gap and thus improve the heat dissipation rate of the magnetic core 40.

[0070] In the above embodiment, the length of the first air gap 61 in the center line direction of the first limb 51 is less than or equal to 1 mm, and the length of the first air gap 61 is 1 mm, 0.7 mm, 0.5 mm, 0.2 mm in an example. The length of the second air gap 62 in the center line direction of the second limb 52 is less than or equal to 1 mm, and the length of the second air gap 62 is 1 mm, 0.6 mm, 0.4 mm, 0.1 mm in an example. It can be understood that the longer the length of the air gap, the smaller the magnetic permeability, the larger the magnetic resistance of the magnetic core 40, and the smaller the excitation inductance of the power converter 20. However, if the length of the air gap is too long, the leakage magnetic field at the air gap will be too large, the magnetic field at the air gap will cut the winding coil 31, and the winding coil 31 at the air gap will generate an induced current, thereby generating eddy current at the air gap and causing heating at the air gap.

[0071] The length of the first air gap 61 and the length of the second air gap 62 are not limited in the embodiment of the application, and the length of the first air gap 61 can be equal to the length of the second air gap 62 in an example. The length of the first air gap 61 can be different from the length of the second air gap 62. It can be understood that the length of the first air gap 61 is equal to the length of the second air gap 62, which can reduce the processing difficulty and processing cost.

[0072] The length of the first air gap 61 in the center line direction of the first limb 51 is less than or equal to 1 mm, and the length of the second air gap 62 in the center line direction of the second limb 52 is less than or equal to 1 mm, which can ensure that the excitation inductance of the power converter 20 is small while avoiding overheating at the air gap.

[0073] In the above embodiment, the first limb 51 further comprises a first root 51c located between the first core portion 51b and the first magnetic core body 41a, and the second limb 52 further comprises a second root 52c located between the second core portion 52b and the second magnetic core body 42a. The first root 51c and the first magnetic core body 41a are in an integrated structure, and the second root 52c and the second magnetic core body 42a are in an integrated structure.

[0074] The first root 51c is located between and spaced apart from the two first side columns 41b. The second root 52c is located between and spaced apart from the two second side columns 42b. The first root 51c and the first magnetic core body 41a are in an integrated structure, facilitating the adhesion of the first core portion 51b and the first end portion 51a to the first magnetic core body 41a, and can limit the position of the first limb 51. At the same time, there is no air gap between the first root 51c and the first magnetic core body 41a, which can avoid the air gap being located at the edge of the first limb 51, resulting in excessive leakage magnetic field.

[0075] The second root 52c is in an integral structure with the second magnetic core body 42a, facilitating the bonding of the second core portion 52b and the second end portion 52a with the second magnetic core body 42a, and the position of the second middle column 52 can be limited. At the same time, there is no air gap between the second root 52c and the second magnetic core body 42a, which can avoid the air gap being located at the edge of the second middle column 52, resulting in excessive leakage magnetic flux.

[0076] In the above embodiment, the length of the first root 51c is less than the length of the first end portion 51a along the center line direction of the first middle column 51. The length of the second root 52c is less than the length of the second end portion 52a along the center line direction of the second middle column 52.

[0077] It can be understood that, since the heat at the air gap needs to be transmitted to the magnetic core 40 through the middle column, the air gap is located between the root and the end portion, and the length of the root is less than the length of the end portion, which can ensure that the position of the air gap on the middle column is closer to the magnetic core 40, thereby ensuring that the heat transfer distance between the air gap and the magnetic core 40 is shorter, and further improving the heat dissipation rate of the magnetic core 40.

[0078] Since the first air gap 61 is located between the first end portion 51a and the first root 51c, and the second air gap 62 is located between the second end portion 52a and the second root 52c, the length of the first root 51c is less than the length of the first end portion 51a, and the length of the second root 52c is less than the length of the second end portion 52a, which can ensure that the first air gap 61 and the second air gap 62 are located on both sides of the first middle column 51 and the second middle column 52, and are closer to the first magnetic core 41 and the second magnetic core 42, thereby shortening the heat transfer distance of the first air gap 61 and the second air gap 62 to the outside of the first magnetic core 41 and the second magnetic core 42, and improving the heat dissipation rate of the first magnetic core 41 and the second magnetic core 42.

[0079] In the above embodiment, the first end portion 51a and the second end portion 52a have a third air gap 63, that is, the first middle column 51 and the second middle column 52 have a third air gap 63. It can be understood that the magnetic core 40 will expand and contract when working, causing the magnetic core 40 to deform, and the third air gap 63 can provide space for the deformation of the first middle column 51 and the second middle column 52, avoiding the first middle column 51 and the second middle column 52 from cracking when deforming due to thermal expansion and contraction.

[0080] In the above embodiment, the third air gap 63 is provided with a heat-conducting adhesive. The heat-conducting adhesive has a certain deformation amount (soft heat-conducting adhesive), and the softness of the heat-conducting adhesive is relatively high. The soft heat-conducting adhesive is usually not solidified, or has elasticity after solidification, and can change its own form to adapt to the deformation of the magnetic core 40 along with the deformation of the magnetic core 40.

[0081] In the above embodiment, the length of the third air gap 63 along the center line direction of the first limb 51 is 0.2mm-1mm, and the length of the third air gap 63 is 0.2mm, 0.4mm, 0.8mm, 1mm in an example. The third air gap 63 can provide space for the deformation of the magnetic core 40, while avoiding the length of the third air gap 63 being too large, resulting in serious leakage of the third air gap 63, and the temperature of the third air gap 63 being too high.

[0082] Please refer to Figure 7 In the above embodiment, the number of the first core portions 51b is multiple, and the multiple first core portions 51b are arranged at intervals along the center line (dashed line in Figure 7 ) of the first limb 51. The fourth air gap 64 is provided between the two adjacent first core portions 51b, and the length of the fourth air gap 64 along the center line direction of the first limb 51 is equal to the length of the first air gap 61.

[0083] The number of the second core portions 52b is multiple, and the multiple second core portions 52b are arranged at intervals along the center line (dashed line in Figure 6 ) of the second limb 52. The fifth air gap 65 is provided between the two adjacent second core portions 52b, and the length of the fifth air gap 65 along the center line direction of the second limb 52 is equal to the length of the second air gap 62.

[0084] The number of the first core portions 51b and the second core portions 52b is multiple, which can increase the number of air gaps on the first limb 51 and the second limb 52, so that the magnetic permeability of the magnetic core 40 (shown in Figure 5 ) becomes smaller, and the magnetic resistance becomes larger. By adjusting the number of the first core portions 51b and the second core portions 52b, the magnetic permeability of the magnetic device 30 (shown in Figure 3 ) can be adjusted to meet the requirements of the power converter 20 (shown in Figure 2 ).

[0085] In the above embodiment, the first heat-conducting sheet is arranged in the first air gap 61, and the length of the first heat-conducting sheet along the center line of the first limb 51 is equal to the length of the first air gap 61.

[0086] In the embodiment in which the first air gap 61 is provided between the first core portion 51b and the first magnetic core body 41a, the first core portion 51b is connected to the first magnetic core body 41a through the first heat-conducting sheet. The first heat-conducting sheet can be adhered together with the first core portion 51b and the first magnetic core body 41a respectively through heat-conducting adhesive.

[0087] In the above embodiment, the first limb 51 includes the first root portion 51c (shown in Figure 6In the embodiment shown in FIG. 1, the first root 51c is in one-piece structure with the first core body 41a, and the first core 51b has the first air gap 61 between the first core body 41a, that is, the first core 51b has the first air gap 61 between the first core 51c and the first root 51c, and the first core 51b is connected to the first root 51c through the first heat-conducting sheet. The first heat-conducting sheet and the first core 51b and the first root 51c can be bonded together through heat-conducting adhesive.

[0088] In the embodiment shown in FIG. 1, the first root 51c is in one-piece structure with the first core body 41a, and the first core 51b has the first air gap 61 between the first core body 41a, that is, the first core 51b has the first air gap 61 between the first core 51c and the first root 51c, and the first core 51b is connected to the first root 51c through the first heat-conducting sheet. The first heat-conducting sheet and the first core 51b and the first root 51c can be bonded together through heat-conducting adhesive.

[0089] In the embodiment shown in FIG. 1, the first root 51c is in one-piece structure with the first core body 41a, and the first core 51b has the first air gap 61 between the first core body 41a, that is, the first core 51b has the first air gap 61 between the first core 51c and the first root 51c, and the first core 51b is connected to the first root 51c through the first heat-conducting sheet. The first heat-conducting sheet and the first core 51b and the first root 51c can be bonded together through heat-conducting adhesive.

[0090] In the embodiment shown in FIG. 1, the first root 51c is in one-piece structure with the first core body 41a, and the first core 51b has the first air gap 61 between the first core body 41a, that is, the first core 51b has the first air gap 61 between the first core 51c and the first root 51c, and the first core 51b is connected to the first root 51c through the first heat-conducting sheet. The first heat-conducting sheet and the first core 51b and the first root 51c can be bonded together through heat-conducting adhesive.

[0091] In the embodiment shown in FIG. 1, the first root 51c is in one-piece structure with the first core body 41a, and the first core 51b has the first air gap 61 between the first core body 41a, that is, the first core 51b has the first air gap 61 between the first core 51c and the first root 51c, and the first core 51b is connected to the first root 51c through the first heat-conducting sheet. The first heat-conducting sheet and the first core 51b and the first root 51c can be bonded together through heat-conducting adhesive.

[0092] In the embodiment shown in FIG. 1, the first root 51c is in one-piece structure with the first core body 41a, and the first core 51b has the first air gap 61 between the first core body 41a, that is, the first core 51b has the first air gap 61 between the first core 51c and the first root 51c, and the first core 51b is connected to the first root 51c through the first heat-conducting sheet. The first heat-conducting sheet and the first core 51b and the first root 51c can be bonded together through heat-conducting adhesive.

[0093] In the embodiment shown in FIG. 1, the first root 51c is in one-piece structure with the first core body 41a, and the first core 51b has the first air gap 61 between the first core body 41a, that is, the first core 51b has the first air gap 61 between the first core 51c and the first root 51c, and the first core 51b is connected to the first root 51c through the first heat-conducting sheet. The first heat-conducting sheet and the first core 51b and the first root 51c can be bonded together through heat-conducting adhesive.

[0094] In the embodiment shown in FIG. 1, the first root 51c is in one-piece structure with the first core body 41a, and the first core 51b has the first air gap 61 between the first core body 41a, that is, the first core 51b has the first air gap 61 between the first core 51c and the first root 51c, and the first core 51b is connected to the first root 51c through the first heat-conducting sheet. The first heat-conducting sheet and the first core 51b and the first root 51c can be bonded together through heat-conducting adhesive.

[0095] In the above embodiments, the first and second heat-conducting sheets are ceramic sheets or epoxy boards. In the embodiments in which the number of the first and second core portions 51b and 52b is plural, the fourth and fifth heat-conducting sheets are also ceramic sheets or epoxy boards.

[0096] The ceramic sheets and the epoxy boards are not magnetically conductive and do not affect the magnetic field. The first, second, fourth and fifth heat-conducting sheets are ceramic sheets or epoxy boards, which do not affect the influence of the air gap on the magnetic core, and at the same time can improve the heat transfer rate at the air gap.

[0097] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A power converter, characterized by, The power converter comprises: a circuit board; a magnetic device disposed on the circuit board, the magnetic device comprising a first magnetic core, a second magnetic core, and a winding coil; the first magnetic core comprising a first magnetic core body and a first limb disposed on the first magnetic core body, the first limb comprising a first end portion and a first core portion, the first core portion being located between the first end portion and the first magnetic core body, the first core portion and the first end portion and the first magnetic core body each having a first air gap therebetween; the second magnetic core comprising a second magnetic core body and a second limb disposed on the second magnetic core body, the second limb comprising a second end portion and a second core portion, the second core portion being located between the second end portion and the second magnetic core body, the second core portion and the second end portion and the second magnetic core body each having a second air gap therebetween; wherein the first limb and the second limb are located between the first magnetic core body and the second magnetic core body, and the center line of the first limb is collinear with the center line of the second limb; the winding coil is wound around the first limb and the second limb.

2. The power converter of claim 1, wherein, In the direction of the center line of the first limb, the distance between the end of the first end portion close to the first core portion and the first magnetic core body is less than the length of the first end portion; In the direction of the center line of the second limb, the distance between the end of the second end portion close to the second core portion and the second magnetic core body is less than the length of the second end portion.

3. A power converter as claimed in claim 1 or 2, characterised in that, In the direction of the center line of the first limb, the length of the first air gap is less than or equal to 1mm; In the direction of the center line of the second limb, the length of the second air gap is less than or equal to 1mm.

4. A power converter according to any one of claims 1-3, characterized in that, The first limb further comprises a first root portion located between the first core portion and the first magnetic core body, and the second limb further comprises a second root portion located between the second core portion and the second magnetic core body; the first root portion and the first magnetic core body are in one body structure, and the second root portion and the second magnetic core body are in one body structure.

5. The power converter of any of claims 1-4, wherein, The number of the first core portions is multiple, and the multiple first core portions are arranged at intervals along the center line of the first limb; the number of the second core portions is multiple, and the multiple second core portions are arranged at intervals along the center line of the second limb; there is a fourth air gap between two adjacent first core portions, and there is a fifth air gap between two adjacent second core portions.

6. The power converter of claim 5, wherein, A first heat-conducting sheet is arranged in the first air gap, and a second heat-conducting sheet is arranged in the second air gap; a fourth heat-conducting sheet is arranged in the fourth air gap, and a fifth heat-conducting sheet is arranged in the fifth air gap.

7. The power converter of claim 6, wherein, The first heat-conducting sheet, the second heat-conducting sheet, the fourth heat-conducting sheet, and the fifth heat-conducting sheet are ceramic sheets or epoxy boards.

8. The power converter of any of claims 1-7, wherein, There is a third air gap between the first end portion and the second end portion.

9. The power converter of claim 8, wherein, A heat-conducting adhesive is arranged in the third air gap.

10. A charging device, characterized by The power converter comprises the power converter of any one of claims 1-9, the power converter being configured to perform power conversion on input electrical energy and output the power-converted electrical energy to a charging gun, and the charging gun being configured to be connected to an electric vehicle.

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