Magnetic device structure and transformer

Abstract

The application discloses a magnetic device structure and a transformer, which comprise a first magnetic core body, an internal liquid cooling pipeline and an external liquid cooling device. The first magnetic core body is formed with a first through cavity. The internal liquid cooling pipeline is arranged in the first through cavity and is in heat conduction connection with the inner wall of the first magnetic core body. The external liquid cooling device is in heat conduction connection with the outer surface of the first magnetic core body and / or the winding. That is, the technical scheme is characterized in that a through cavity is arranged in the magnetic core body, the internal liquid cooling pipeline is in heat conduction connection with the inner wall of the through cavity, and the external liquid cooling device is arranged on the outer surface of the magnetic core and / or the winding side, so that a cooperative heat dissipation path of "inner near heat source heat exchange + outer surface heat exchange" is formed, the heat transfer path from the inside of the magnetic core / winding to the cooling medium is significantly shortened, the interface thermal resistance and the internal thermal resistance are reduced, the heat of the middle column and the high loss area hot spot is quickly pumped, the temperature difference between the inside and the outside of the device is reduced, and the temperature uniformity is improved. Under the same environmental and volume conditions, the highest junction / heat spot temperature rise can be effectively reduced.

Description

Technical Field

[0001] This invention relates to the field of transformer technology, and more particularly to a magnetic device structure and a transformer. Background Technology

[0002] As the power rating of power conversion units continues to increase, the losses of magnetic components (such as transformers and inductors) also increase: the magnetic core generates significant hysteresis and eddy current losses under high-frequency strong magnetic fields, and the copper losses generated by the windings under high currents also increase simultaneously. Due to size and installation space limitations, it is difficult to reduce magnetic flux density / current density or expand the convection heat transfer area by increasing the size of the components, resulting in higher temperature rise of the component body and a greater temperature difference between the inside and outside. Local hot spots (especially in the central column and dense winding areas) become key bottlenecks affecting reliability and lifespan.

[0003] The heat dissipation paths in related technologies mainly fall into two categories: air cooling and external liquid cooling. Air cooling relies on environmental and airflow conditions, and its reliability is limited under harsh operating conditions such as dust, salt spray, and strong vibration. External liquid cooling solutions typically employ a heat transfer path of "integral potting of magnetic components—thermal conductive adhesive—metal tank—liquid cooling plate." Its advantages are good systematization and versatility, but as device power, size, and losses increase, internal heat must traverse a long heat conduction path and pass through multiple layers of interfacial thermal resistance, resulting in limited efficiency of internal hot spots being conducted to the external liquid cooling plate. At the same time, heat flow inside the magnetic core and windings is difficult to remove in a timely manner, leading to large internal and external temperature differences and uneven temperature distribution, which become the core obstacle to further improving the power density and power limit of traditional liquid cooling solutions. Summary of the Invention

[0004] The main objective of this invention is to provide a magnetic device structure and a transformer to at least solve the technical problems mentioned in the related art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] In a first aspect, the present invention provides a magnetic device structure, the magnetic device structure comprising a first magnetic core body, an internal liquid cooling pipe and an external liquid cooling device;

[0007] The first magnetic core body has a first cavity, the internal liquid cooling pipe passes through the first cavity and is thermally connected to the inner wall of the first magnetic core body, the first magnetic core body is wound with a first winding, and the external liquid cooling device is thermally connected to the outer surface of the first magnetic core body and / or the winding.

[0008] The internal liquid cooling pipe is used to conduct heat generated inside the first magnetic core body to an external cooling system through coolant, and the external liquid cooling device is used to conduct heat from the outside of the first magnetic core and / or the first winding to the cooling system through coolant.

[0009] A second aspect of the present invention also provides a transformer, including a transformer body and a magnetic device structure as described in the first aspect; the magnetic device structure is disposed on the transformer body.

[0010] The magnetic device structure and transformer of the present invention form a synergistic heat dissipation path of "internal heat source heat exchange + external surface heat exchange" by setting a through cavity in the magnetic core body and thermally connecting the internal liquid cooling pipe to the inner wall of the cavity, and simultaneously configuring external liquid cooling devices on the outer surface of the magnetic core and / or the winding side. This significantly shortens the heat transfer path from the inside of the magnetic core / winding to the cooling medium, reduces interface thermal resistance and internal thermal resistance, quickly pumps heat from the central column and high-loss hot spots, reduces the temperature difference between the inside and outside of the device, and improves temperature uniformity. Under the same environmental and volume conditions, it can effectively reduce the maximum junction / hot spot temperature rise, increase the power density and power limit of the magnetic device, and help reduce magnetic core demagnetization, insulation aging and winding loss gain caused by overheating, thereby improving the overall reliability and lifespan of the system. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of the thermal resistance model of a magnetic device structure in related technologies.

[0013] Figure 2 This is a schematic diagram of the thermal resistance model of a magnetic device structure provided in an embodiment of this application;

[0014] Figure 3 This is a schematic diagram of a magnetic device structure provided in an embodiment of this application;

[0015] Figure 4 This is a three-dimensional schematic diagram of a magnetic device structure provided in an embodiment of this application;

[0016] Figure 5 This is a three-dimensional schematic diagram of a magnetic device structure provided in an embodiment of this application;

[0017] Figure 6 This is a three-dimensional schematic diagram of a magnetic device structure provided in an embodiment of this application.

[0018] Reference numerals: First magnetic core body 10, internal liquid cooling pipe 20, external liquid cooling device 30, second magnetic core body 40, central column 101, side wall 102, first winding 103, first cavity 1011. Detailed Implementation

[0019] To make the inventive objectives, features, and advantages of this application more apparent and understandable, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0021] In the description of the embodiments of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. The term "multiple" means two or more, unless otherwise explicitly specified. The term "comprising" indicates the presence of the described feature, whole, step, operation, element, and / or component, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or sets thereof. The term "and / or" describes the relationship between related objects, indicating that three relationships may exist. For example, A and / or B may include three cases: A existing alone, A and B existing simultaneously, and B existing alone. The character " / " generally indicates that the related objects before and after are in an "or" relationship.

[0022] Unless otherwise defined, all technical terms used in the embodiments of this application have the same meaning as commonly understood by one of ordinary skill in the art; the terms used in the embodiments of this application are for the purpose of describing specific embodiments only and are not intended to limit this application; the terms "comprising" and "having" and any variations thereof in the specification, claims and foregoing description of the drawings of this application are intended to cover non-exclusive inclusion.

[0023] Furthermore, terms such as "exemplary," "for example," and "optional" are used to indicate illustrative purposes. Any technical solution described by the above terms in the embodiments of this application should not be construed as being more preferred or advantageous than other technical solutions. Specifically, these terms are intended to present the relevant technical concepts in terms of specific implementation methods.

[0024] Please see Figure 1 One heat dissipation equivalent model for a liquid-cooled magnetic component in related technologies is a series thermal resistance network of "internal conduction + interface heat conduction + external liquid cooling". Heat inside the magnetic component is transferred sequentially through the magnetic core, windings, and internal thermally conductive adhesive to the outer surface of the device, and then through the thermally conductive adhesive to the heat sink and liquid cooling plate. Based on the thermal resistance formula R = L / (λ*S), where L is the heat transfer path length, S is the heat transfer cross-sectional area, and λ is the thermal conductivity of the material, it can be seen that for a large magnetic component, the internal thermal resistance R... in Due to the long path, limited cross-section, and relatively low thermal conductivity of the material, which is much greater than the interfacial contact thermal resistance R... jc With R jd Therefore, regardless of the external liquid cooling capacity, the dominant factor in the internal hotspot temperature remains R. in The key to improving the heat dissipation capacity of liquid-cooled magnetic components lies in shortening the internal heat transfer distance, increasing the effective contact area, or improving the internal equivalent thermal conductivity, which essentially means reducing R. in .

[0025] To address the technical challenges of high internal thermal resistance, large internal and external temperature differences, and difficulty in removing hot spots in existing liquid-cooled magnetic components, please refer to the following in sequence. Figures 2 to 5 This application proposes a magnetic device structure.

[0026] The magnetic device structure includes at least a first magnetic core body 10, an internal liquid cooling pipe 20, and an external liquid cooling device 30. The components are described below:

[0027] The first magnetic core body 10 may be a soft magnetic material (such as ferrite, nanocrystalline, amorphous or laminated magnet), and a first through cavity 1011 is formed along its length; preferably, the first through cavity 1011 is located at the axis of the central column and extends axially.

[0028] The internal liquid cooling pipe 20 can be a hollow pipe structure made of electrically insulating and thermally conductive materials such as PET, PTFE, or ceramic. This internal liquid cooling pipe 20 passes through the first cavity 1011, and a thermally conductive interface layer (such as a thermally conductive silicone sheet / thermally conductive potting compound / thermally conductive ceramic slurry) is laid between the outer wall of the pipe and the inner wall of the cavity, forming a surface-fitting thermally conductive connection and electrical insulation. Furthermore, both ends of the internal liquid cooling pipe 20 are connected to an external cooling circuit via quick connectors, allowing the coolant to circulate within the pipe to remove heat from the inside of the first magnetic core body 10. A first winding 103 (made of copper foil / enameled wire / flat copper wire with interlayer insulation) is also wound around the outer periphery of the first magnetic core body 10.

[0029] The external liquid cooling device 30 can be a hollow pipe structure made of electrically insulating and thermally conductive materials such as PET, PTFE, or ceramics (e.g., Figure 5 As shown, it is either wrapped around the sidewall of the magnetic core or a flat liquid-cooled structure (such as...). Figure 3 As shown, the cold plate is mainly disposed on the outer surface of the first magnetic core body 10 and / or the outer side of the first winding 103, and is thermally connected through a thermally conductive interface material; wherein, the internal cooling channel of the external liquid cooling device 30 is connected to the external cooling circuit (external cooling system), thereby dissipating the heat from the outside of the first magnetic core body 10 and the first winding 103.

[0030] It should be noted that the internal liquid cooling pipe 20 and the internal cooling channel of the external liquid cooling device 30 can be connected to form the same circulating cooling loop; or, the external cooling system connected to the internal liquid cooling pipe 20 and the external cooling system connected to the external liquid cooling device 30 can be independent and circulate separately. The above two schemes can be selected according to the actual heat load, flow rate and pressure drop distribution, redundancy and reliability requirements, and structural layout space.

[0031] In this embodiment, the internal liquid cooling pipe 20 establishes a near-heat source heat exchange surface at the center of the cavity. The heat generated in the core's central column / high-loss area is transferred to the pipe via the thermally conductive interface layer through the shortest path and carried away by the coolant. The external liquid cooling device 30 simultaneously performs convective heat exchange on the core sidewall and the outer surface of the winding, achieving coordinated heat dissipation through "direct internal heat extraction + external surface heat exchange." By shortening the heat flow path, increasing the contact area, and reducing the interface thermal resistance, the internal equivalent thermal resistance and hot spot temperature rise can be significantly reduced, improving the temperature uniformity and allowable power density of the magnetic device.

[0032] As can be seen, the magnetic device structure of this application, by setting a through cavity in the magnetic core body and thermally connecting the internal liquid cooling pipe to the inner wall of the cavity, and simultaneously configuring external liquid cooling devices on the outer surface of the magnetic core and / or the winding side, forms a synergistic heat dissipation path of "internal heat source heat exchange + external surface heat exchange". This significantly shortens the heat transfer path from the inside of the magnetic core / winding to the cooling medium, reduces interface thermal resistance and internal thermal resistance, quickly pumps heat from the central column and high-loss hot spots, reduces the temperature difference between the inside and outside of the device and improves temperature uniformity. Under the same environmental and volume conditions, it can effectively reduce the maximum junction / hot spot temperature rise, increase the power density and power limit of the magnetic device, and help reduce magnetic core demagnetization, insulation aging and winding loss gain caused by overheating, thereby improving the overall reliability and lifespan of the system.

[0033] In an optional embodiment of this application, the first magnetic core body 10 includes a central column 101 and a sidewall 102 surrounding the central column 101.

[0034] Specifically, the first cavity 1011 is located in the central region of the central column 101 and preferably extends along the central column axis; the external liquid cooling device 30 is arranged on the outside of the side wall 102, and a thermally conductive interface layer is provided between the side wall 102 and the external liquid cooling device 30 to form a surface-fitting thermally conductive connection and maintain electrical insulation, so that while the internal liquid cooling pipe 20 extracts heat from the central column near the heat source, the external liquid cooling device 30 performs surface heat exchange between the side wall and the outer surface of the winding, thereby synergistically reducing the internal thermal resistance and the external surface thermal resistance.

[0035] Please see Figure 5 In a preferred arrangement, there are at least four external liquid cooling pipes, which are distributed around the sidewall 102 of the first magnetic core body 10 along its four outer quadrants (arranged at equal intervals, up, down, left, right or at equal angles) and are thermally connected to the sidewall 102 through a thermally conductive interface layer; there are at least two internal liquid cooling pipes, which are respectively axially inserted into the first through cavity 1011 along the central column 101 and thermally connected to its inner wall through a thermally conductive interface layer.

[0036] Specifically, four external liquid-cooled pipes are used to preferentially remove heat from the sidewalls and the outer surface of the first winding 103, while two internal liquid-cooled pipes are used to directly extract heat from the area near the heat source in the central column. The internal cooling channels of each pipe can be connected in series or in parallel with the external cooling circuit, and the branch flow ratio and balance can be achieved through a distribution manifold. In order to increase the heat exchange area, the cross-sections of the external and internal liquid-cooled pipes are preferably flat or elliptical.

[0037] Please return and refer to Figure 3 The flat liquid cooling structure is arranged vertically on the outside of the first magnetic core body 10 and is thermally connected to the outer surface of the side wall 102 through a thermal interface layer.

[0038] Specifically, the internal cooling channels of this flat-plate liquid-cooled structure can be connected to the internal liquid-cooled pipes 20 to form the same cooling circuit or a parallel system, achieving coordinated heat exchange between the heat source near the central column (heat extracted by the internal liquid-cooled pipes 20) and the sidewall / winding outer surface (heat extracted by the cold plate). Preferably, the thermally conductive interface layer has both thermal conductivity and electrical insulation functions, and the flat-plate liquid-cooled structure can employ microchannels or pin-fin flow channels to improve the convective heat transfer coefficient.

[0039] Please see Figure 6 The magnetic device structure also includes a second magnetic core body 40, which has a second through cavity extending along its thickness direction.

[0040] Specifically, at least a portion of the internal liquid cooling pipe 20 passes through the first cavity 1011 and is thermally connected to the inner wall of the cavity of the first magnetic core body 10 via a thermally conductive interface layer. At least a portion of the pipe also passes through the second cavity 4011 and is thermally connected to the inner wall of the cavity of the second magnetic core body 40 via a thermally conductive interface layer. This allows the same circulating coolant to serve the internal near-heat source areas of the two magnetic core bodies (first magnetic core body 10 and second magnetic core body 40) in series or parallel. Simultaneously, a flat liquid cooling structure is arranged between the first magnetic core body 10 and the second magnetic core body 40. It is thermally connected to the outer surfaces of the two magnetic cores (and the corresponding outer surfaces of the windings) via a thermally conductive interface layer and is connected to the cooling circuit accessed by the internal liquid cooling pipe 20. This constructs a synergistic heat exchange path of "internal cooling of the first magnetic core + intermediate surface cooling of the cold plate + internal cooling of the second magnetic core", which further reduces the equivalent thermal resistance inside the two magnetic cores, balances the temperature field, and improves the overall heat dissipation efficiency.

[0041] In an optional embodiment of this application, one side of the flat liquid cooling structure is thermally connected to the first magnetic core body and the first winding surface via a thermally conductive interface layer, and the other side is thermally connected to the second magnetic core body and the second winding surface on which it is wound via a thermally conductive interface layer, so as to establish a double-sided heat exchange channel and improve the overall heat dissipation efficiency under the premise of electrical insulation.

[0042] This application also provides a method for fabricating a magnetic device structure, which includes at least the following steps:

[0043] S1 core machining (pre-set through hole): A through hole (first through cavity) is machined axially at the position of the core pillar. The axis of the through hole is coaxial with the axis of the pillar. The hole wall is chamfered and deburred to avoid stress concentration and scratching of the pipe. The diameter tolerance of the through hole is preferably ±0.1~±0.2mm, and the surface roughness is preferably Ra≤1.6μm to reduce interfacial thermal resistance and facilitate sealing.

[0044] S2 Internal Liquid Cooling Piping Assembly (Internal Through-hole in the Central Column): Select a cooling pipe with an outer diameter 1–2 mm smaller than the through-hole diameter (material can be insulating and thermally conductive materials such as PET, PTFE, or ceramics), and insert it into the through-hole in the central column, ensuring the pipe runs along the entire length of the magnetic core axis. To establish a stable heat conduction channel, uniformly coat or fill the space between the outer wall of the pipe and the hole wall with thermally conductive adhesive / thermal interface material (thermal conductivity ≥ 1.5 W·m). -1 •K-1), and a fixture is used to limit the concentricity and ensure that the coating thickness is consistent. After curing at room temperature or with heat, a surface-fitting thermally conductive connection is formed. This arrangement allows the heat inside the central column to be transferred to the coolant inside the pipe through the shortest path.

[0045] S3 winding-side piping arrangement (inter-turn / inter-layer access): Cooling pipes are installed in the reserved channels between winding turns and layers. Flat or elliptical cross-section pipes are preferred to increase the contact area with the winding's adjacent surface. Positioning is achieved through bonding with a thin layer of thermally conductive interface material, with adhesive application used for limiting if necessary, to prevent mechanical stress from acting on the winding insulation. This arrangement shortens the heat transfer path from the winding interior to the cooling medium, reducing hotspot temperature rise.

[0046] S4 Piping Connection Topology (External Loop Connection): Based on structural characteristics and heat flux density, select one or more of the following connection methods:

[0047] a) Hole-to-hole independent: Each through hole is equipped with a pipe, and the outlet ends are connected in series or parallel through pipe joints outside the magnetic component;

[0048] b) Single-tube serial connection: A single tube is sequentially passed out of / into multiple through holes to form a single circuit for the entire magnetic component;

[0049] c) Multiple magnetic components in series: A single pipe runs through multiple magnetic components, forming a joint heat dissipation system for multiple magnetic components;

[0050] d) Zoned connection: Branch circuits are arranged in zones according to the hot spot area of ​​the central column and the side wall / winding zone, and connected in series / parallel to match different heat loads.

[0051] Each branch is connected to the external cooling circuit via quick-connect or compression fittings. It is recommended to install flow balancing valves or flow restrictor plates at the distribution / combination points to achieve flow balance.

[0052] S5 Thermal Conductivity and Fixing (Interface Filling): Thermally conductive adhesive is used to fill and cure the gaps between the pipe and the core hole wall, and between the pipe and the winding adjacent surface, to achieve the dual function of thermal conduction and mechanical fixing; thermally conductive pads (which also serve as electrical insulation) are arranged between the flat cold plate or the external annular tube and the core side wall / coil outer surface to create a large area of ​​thermal conduction path and avoid electrical short circuits.

[0053] S6 End Seal (Anti-Leakage Design): A rubber sealing structure (such as an O-ring + gland / seal seat) is installed at the inlet and outlet ends of the heat dissipation pipe to achieve end sealing through elastic deformation; a floating allowance (such as a corrugated section or flexible joint) is provided to accommodate possible thermal expansion and contraction displacement. The sealing material should be compatible with the coolant and meet the temperature and pressure resistance requirements.

[0054] S7 Cooling Loop Connection and Commissioning: Connect the beginning and end of the pipes to the external cooling circulation system (including the circulating pump, heat exchanger / radiator, liquid storage tank, and temperature / flow / pressure sensors) according to process requirements.

[0055] Leakage and pressure resistance test: Increase the pressure to 1.25–1.5 times the working pressure and hold it to check the seals of all joints and ends;

[0056] Exhaust and flow rate setting: Start the circulation to complete the exhaust, and adjust the flow rate according to the branch heat load;

[0057] Thermal performance verification: Hot spot temperature, internal and external temperature difference and steady-state temperature rise were tested at representative power and frequency to confirm that the design specifications were met.

[0058] In this embodiment, the cooling medium is directly introduced into the magnetic core column and the area near the heat source of the winding through the above method, which significantly shortens the heat transfer path, reduces the internal equivalent thermal resistance, effectively suppresses the temperature rise of hot spots and improves temperature uniformity. Compared with the traditional external liquid cooling path of "filling-can-cold plate", this embodiment can significantly improve the heat dissipation capacity, allowable power density and reliability of magnetic devices under the same volume and environmental conditions.

[0059] This application also provides a transformer, including a transformer body and a magnetic device structure as described in the above embodiments; the magnetic device structure is disposed on the transformer body.

[0060] The magnetic device structure and transformer of the present application embodiment also have the following beneficial effects:

[0061] 1) The heat dissipation scheme of using liquid cooling pipes to enter the interior of the magnetic component can reduce the thermal resistance of the magnetic component, reduce the temperature difference between the inside and outside of the magnetic component, solve the temperature of the hottest spot inside, thereby breaking through the heat dissipation bottleneck of liquid cooling magnetic components and proposing the power level and power density of the magnetic component.

[0062] 2) Liquid cooling pipes have both insulation and heat conduction functions, which can effectively remove heat from magnetic components without requiring additional safety measures.

[0063] 3) The heat dissipation solution provided in this application does not require overall potting, which reduces the amount of potting compound used and lowers costs and weight;

[0064] 4) The liquid cooling pipe placement scheme of this application is flexible and can be combined with existing liquid cooling planar schemes to design a variety of heat dissipation measures. Heat dissipation schemes can be designed for different application scenarios to achieve the optimal design of cost and performance.

[0065] In summary, the embodiments of this application have excellent heat dissipation performance, which can reduce the temperature rise of magnetic devices, further improve power density, reduce the cost and weight of magnetic components, and improve reliability and lifespan.

[0066] The specific embodiments of the invention have been described in detail above, but these are merely examples, and the invention is not limited to the specific embodiments described above. For those skilled in the art, any equivalent modifications or substitutions to the invention are also within the scope of this invention. Therefore, all equivalent transformations, modifications, and improvements made without departing from the spirit and principles of this invention should be covered within the scope of this invention.

Claims

1. A magnetic device structure, characterized in that, The magnetic device structure includes a first magnetic core body, an internal liquid cooling pipe, and an external liquid cooling device. The first magnetic core body has a first cavity, the internal liquid cooling pipe passes through the first cavity and is thermally connected to the inner wall of the first magnetic core body, the first magnetic core body is wound with a first winding, and the external liquid cooling device is thermally connected to the outer surface of the first magnetic core body and / or the winding. The internal liquid cooling pipe is used to conduct heat generated inside the first magnetic core body to an external cooling system through coolant, and the external liquid cooling device is used to conduct heat from the outside of the first magnetic core and / or the first winding to the cooling system through coolant.

2. The magnetic device structure as described in claim 1, characterized in that, The magnetic core includes a central post and sidewalls surrounding the central post; The cavity is located in the central region of the central column, and the sidewall is thermally connected to the external liquid cooling device.

3. The magnetic device structure as described in claim 2, characterized in that, The external liquid cooling device includes external liquid cooling pipes or a flat liquid cooling structure.

4. The magnetic device structure as described in claim 3, characterized in that, The external liquid cooling pipes are at least four, and the internal liquid cooling pipes are at least two; The two internal liquid cooling pipes are respectively inserted into the first through cavity along the central column axis and are thermally connected to its inner wall through a thermally conductive interface layer. The four external liquid cooling pipes are distributed in four quadrants around the sidewall of the first magnetic core body and are thermally connected to the sidewall through a thermal interface layer.

5. The magnetic device structure as described in claim 3, characterized in that, The flat liquid cooling structure is arranged vertically on the outside of the magnetic core body, and the internal cooling channel of the flat liquid cooling structure is connected to the internal liquid cooling pipe.

6. The magnetic device structure as described in claim 3, characterized in that, The magnetic device structure also includes a second magnetic core body; The second magnetic core body has a second through cavity, at least a portion of the internal liquid cooling pipe passes through the first through cavity and is thermally connected to the inner wall of the first magnetic core body, and at least a portion passes through the second through cavity and is thermally connected to the inner wall of the second magnetic core body. The flat liquid cooling structure is disposed between the first magnetic core body and the second magnetic core body.

7. The magnetic device structure as described in claim 6, characterized in that, One side of the flat liquid-cooled structure is thermally connected to the first magnetic core body and the first winding, and the other side is thermally connected to the second magnetic core body and the second winding thereon.

8. The magnetic device structure according to any one of claims 1 to 7, characterized in that, A thermally conductive interface layer is provided between the outer surface of the internal liquid cooling pipe and the inner wall of the first magnetic core body. The thermally conductive interface layer is used to conduct the heat generated inside the first magnetic core body to the internal liquid cooling pipe and form electrical insulation.

9. The magnetic device structure as described in claim 1, characterized in that, The internal liquid cooling pipe is connected to the internal cooling channel of the external liquid cooling device; Alternatively, the external cooling system connected to the internal liquid cooling pipes is independent of the external cooling system connected to the external liquid cooling device.

10. A transformer, characterized in that, Includes the transformer body and the magnetic device structure as described in any one of claims 1 to 9; The magnetic device structure is disposed on the transformer body.

Images