A package housing for high-power high-frequency transformers

Abstract

This application belongs to the field of transformer equipment, specifically disclosing a casing for a high-power high-frequency transformer. The casing includes a base plate and a casing body, which is detachably mounted on the upper surface of the base plate. The casing body has a through-cavity for accommodating the high-frequency transformer. The top and side walls of the casing body have several slot structures. The accommodating cavity and all the slot structures are filled with a thermally conductive and insulating filler layer. Through the structural design of the casing for the high-power high-frequency transformer in this application, the annular path of eddy currents can be disrupted, the skin effect weakened, eddy current losses effectively reduced, heat dissipation efficiency accelerated, and the overall safety performance of the equipment improved.

Description

Technical Field

[0001] This application belongs to the field of transformer equipment, and more specifically, relates to an enclosure for a high-power high-frequency transformer. Background Technology

[0002] High-power, high-frequency transformers typically require enclosures to ensure their safety, compliance, and long-term stable operation. The enclosure design must be customized according to specific application scenarios (such as power rating, operating frequency, and environmental conditions) to meet the requirements of balanced protection, heat dissipation, and electromagnetic compatibility. Common transformer enclosures are mainly circular and square.

[0003] In related technologies, traditional transformers require consideration of heat dissipation and moisture protection, seismic reinforcement, and electromagnetic shielding during design and application. The most common method is to use potting compound (such as epoxy resin or silicone) to fill the internal gaps of the transformer, conducting heat from the windings to the metal casing to prevent localized overheating. This also improves the transformer's protection and insulation levels, as well as its own thermal conductivity. The metal casing can reflect / absorb electromagnetic waves during operation, reducing radiated interference and improving electromagnetic interference resistance.

[0004] However, in high-frequency operating environments, the winding current frequency of high-frequency transformers is typically in the tens of kHz to MHz range, generating a high-frequency alternating magnetic field. The metal casing (including welding materials or assembly screws at casing seams), acting as a conductor, will generate strong eddy currents due to electromagnetic induction in the high-frequency magnetic field. Eddy current losses are proportional to the square of the frequency, leading to a sharp increase in losses and severe casing heating. This can even cause insulation aging or fire risks due to overheating. Furthermore, high-frequency currents exhibit a skin effect, causing eddy currents to be mainly distributed on the surface of the metal casing. This creates high-density current paths on the casing surface, reducing the effective conductive cross-sectional area, further increasing local resistance, and exacerbating Joule losses. Particularly at casing seams, corners, and other structural locations, abrupt changes in eddy current paths can easily form "current vortices," generating localized hot spots and posing safety hazards. Utility Model Content

[0005] To address the shortcomings of existing technologies, this application provides a packaging shell for high-power high-frequency transformers, aiming to solve the problems of high eddy current losses, severe skin effect, and low heat dissipation efficiency in existing high-power high-frequency transformer packaging shells.

[0006] This application provides a packaging shell for a high-power high-frequency transformer, specifically including a base plate and a shell body. The shell body is detachably installed on the upper surface of the base plate. The interior of the shell body has a downward through-hole for accommodating the high-frequency transformer. The top and side walls of the shell body are provided with several slot structures. The accommodating cavity and all the slot structures are filled with a thermally conductive and insulating filler layer.

[0007] Compared with the prior art, the above-described technical solutions conceived in this application have the advantage that, due to the detachable shell and base plate of the high-power high-frequency transformer, the assembly gap can be precisely controlled, thereby effectively blocking the closed eddy current loop and reducing eddy current losses. Furthermore, the top and side walls of the shell body are provided with slot structures, which disrupt the annular path of the eddy current and weaken the skin effect. At the same time, the cavity and all slot structures are filled with a thermally conductive and insulating filling layer, which provides electrical insulation and forms a continuous thermally conductive channel, allowing the transformer heat to dissipate quickly, thus achieving the beneficial effect of improving the overall safety performance of the equipment.

[0008] As a further preferred embodiment, both ends of several of the groove structures are physically separated from the edge of the outer shell body along the length direction.

[0009] As a further preferred embodiment, the outer shell body includes a top cover plate and a side shell, the side shell being a square shell structure with openings at both the top and bottom ends, and the top cover plate and bottom plate being detachably connected to the upper and lower end faces of the side shell, respectively.

[0010] As a further preferred embodiment, a conductive buffer layer is provided at the connection between the top cover and the side shell, and at the connection between the bottom plate and the side shell.

[0011] As a further preferred embodiment, all four corners of the side shell are set as rounded corners with a radius of not less than 5mm.

[0012] As a further preferred embodiment, the groove structure includes: a plurality of first grooves formed on the top cover plate; a plurality of second grooves and third grooves formed on the side shell; the second grooves and third grooves are respectively located on two opposite surfaces of the side shell.

[0013] As a further preferred embodiment, the width of the second groove is greater than the width of the third groove.

[0014] As a further preferred embodiment, the portion of the upper surface of the base plate located within the accommodating cavity is coated with thermally conductive silicone grease.

[0015] As a further preferred embodiment, the projected area of ​​the base plate in the vertical direction is larger than the projected area of ​​the outer shell body, and mounting holes are provided at all four corners of the base plate.

[0016] As a further preferred embodiment, the outer shell body is an aluminum-based silicon carbide metal-based composite component.

[0017] In summary, compared with the prior art, the technical solutions conceived in this application have the following main technical advantages: 1. In this application, the outer shell and the base plate are detachable, the assembly gap is controllable, the closed eddy current loop is blocked, and the eddy current loss is reduced; at the same time, the top and side walls of the outer shell are provided with groove structures to disrupt the eddy current ring path, weaken the skin effect, and further reduce the high-frequency additional loss.

[0018] 2. In this application, the accommodating cavity and all the tank structures are filled with a thermally conductive and insulating filler layer to form a continuous three-dimensional thermally conductive channel, so that heat is quickly conducted to the surface of the outer shell; the inner surface of the bottom plate is simultaneously covered with thermally conductive silicone grease to accelerate the thermal conductivity of the transformer.

[0019] 3. In this application, the thermally conductive insulating filler layer also serves as an electrical insulating barrier. Together with the rounded corners of the side shell and the conductive buffer layer located at the connection between the top cover plate and the side shell and the connection between the bottom plate and the side shell, it eliminates the risk of local electric field concentration and discharge, and improves the overall safety performance of the device. Attached Figure Description

[0020] Figure 1 This is a first-view overall structural diagram of the packaging shell provided in an embodiment of this application; Figure 2 This is a schematic diagram of the overall structure of the packaging shell from a second perspective, provided in an embodiment of this application. Figure 3 This is a high-frequency transformer model diagram provided in the embodiments of this application; Figure 4 It is a vector diagram of the planar magnetic field strength of a high-frequency transformer generated through simulation. Figure 5 It is a vector diagram of the planar electric field intensity of a high-frequency transformer generated through simulation. Figure 6 This is a three-dimensional magnetic field strength vector diagram of a high-frequency transformer generated through simulation. Figure 7 It is a vector diagram of the three-dimensional electric field intensity of a high-frequency transformer generated through simulation. Figure 8 This is a temperature simulation diagram of a high-frequency transformer packaged using existing encapsulation housings; Figure 9 This is a temperature simulation diagram of a high-frequency transformer packaged using the packaging shell provided in the embodiments of this application.

[0021] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein: 1. Base plate; 11. Mounting hole; 2. Outer shell body; 21. Top cover plate; 22. Side shell; 3. Slot structure; 31. First slot; 32. Second slot; 33. Third slot; 41. Top E-type magnet; 42. Bottom E-type magnet; 43. Core gap; 51. Primary coil; 511. Primary winding end point; 61. Secondary coil; 611. Secondary winding end point; 71. Planar air domain; 72. Three-dimensional composite material domain; 81. Planar magnetic field vector distribution; 82. Planar electric field vector distribution; 91. Three-dimensional magnetic field vector distribution; 92. Three-dimensional electric field vector distribution. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0023] Common high-power high-frequency transformers primarily use circular or square casings. Circular casings offer geometric symmetry, resulting in a more uniform magnetic field distribution and reducing magnetic field concentration at corners. This provides more balanced shielding against high-frequency electromagnetic fields, effectively reducing leakage flux and electromagnetic interference. However, circular casings may require custom-made brackets for installation, leading to relatively low space utilization. Furthermore, the processing of circular casings involves rolling or casting, resulting in higher mold costs, especially when customizing non-standard sizes, leading to low production efficiency and increased costs. Square casings, on the other hand, have a regular structure, facilitating modular installation and stacking, and offering high space utilization. Their planar structure is more conducive to heat sink integration. The mature sheet metal cutting and bending processes result in low processing costs and easier standardization, making them suitable for mass production. However, the corners of square casings may experience reduced shielding efficiency due to magnetic field concentration, especially at high frequencies. The edge effect of the corners can exacerbate electromagnetic field leakage, affecting shielding effectiveness. Additionally, the metal casing used in square casings can generate strong eddy currents in high-frequency magnetic fields due to electromagnetic induction, resulting in significant eddy current losses. Moreover, the skin effect of high-frequency currents can easily generate localized hot spots, posing safety hazards. Taking into account both cost and production efficiency, this application prefers a square casing and conducts improved design based on this to overcome its insufficient shielding performance, while also solving the problems of high eddy current loss, severe skin effect and low heat dissipation efficiency of metal casings for high-power high-frequency transformers.

[0024] Commonly used encapsulation shell materials can be divided into two categories: metallic and non-metallic. Among metallic materials, aluminum alloys (lightweight and with excellent processing performance, and improved corrosion resistance after anodizing) and galvanized steel sheets (low cost and high mechanical strength, with the coating providing basic electromagnetic shielding) are the main types, suitable for applications requiring high power and strong electromagnetic shielding. Among non-metallic materials, PPS (polyphenylene sulfide) / PBT (polybutylene terephthalate) and LCP (liquid crystal polymer) offer significant advantages in insulation, corrosion resistance, and cost control, and are commonly used in miniaturized and low-frequency designs. This application targets high-power, high-frequency transformers, selecting aluminum-based silicon carbide (AlSiC) metal matrix composite materials as the encapsulation shell. AlSiC combines the advantages of both metallic and non-metallic materials, significantly improving key performance aspects such as thermal conductivity and electromagnetic shielding, making it particularly suitable for high-power, high-frequency applications.

[0025] Reference Figures 1-2 The present application discloses an encapsulation housing for a high-power high-frequency transformer, which includes a base plate 1 and a housing body 2. The housing body 2 is detachably installed on the upper surface of the base plate 1, and the two are reliably connected by fasteners, which facilitates assembly and maintenance, and allows for precise control of the joint gap and suppression of closed eddy currents.

[0026] In this embodiment, the outer shell body 2 is made of aluminum-based silicon carbide (AlSiC) metal matrix composite material, which takes into account high thermal conductivity, low coefficient of thermal expansion and excellent mechanical strength; the inner wall is formed by copper-nickel sputtering process to form a composite conductive layer, and the layers are isolated by high-insulation epoxy resin to form a distributed eddy current shielding structure, which significantly weakens high-frequency eddy currents and their additional losses; the base plate 1 is also made of aluminum-based composite material, and the surface is treated with hard anodizing, which not only improves wear resistance and corrosion resistance, but also forms an insulating oxide film between the metal matrix and the thermal grease to prevent electrochemical corrosion.

[0027] Specifically, the interior of the outer casing 2 has a downward-through cavity for accommodating the high-frequency transformer. Several slot structures 3 are formed on the top and side walls of the outer casing 2. The accommodating cavity and all slot structures 3 are filled with a thermally conductive insulating filler layer, creating a continuous thermally conductive channel in three-dimensional space to achieve rapid and uniform heat diffusion. The portion of the upper surface of the base plate 1 located within the accommodating cavity is pre-coated with thermally conductive silicone grease, which adheres tightly to the thermal interface of the transformer core / winding, enhancing the heat conduction of the high-frequency transformer. The thermally conductive insulating filler layer also acts as an electrical insulation barrier, maintaining reliable insulation even under high voltage gradients. To facilitate the overall installation of the encapsulated casing, the projected area of ​​the base plate 1 in the vertical direction is larger than the projected area of ​​the outer casing 2. Mounting holes 11 are formed at the four corners of the base plate 1. In this embodiment, the mounting holes 11 can be set as oblong mounting holes to facilitate floating installation of the entire unit and absorb stress caused by thermal expansion and contraction.

[0028] More specifically, the outer casing 2 includes a top cover 21 and a side shell 22. The side shell 22 is a square shell structure with openings at both the top and bottom. The top cover 21 and the bottom plate 1 are detachably connected to the upper and lower end faces of the side shell 22, respectively, so that the entire encapsulation casing adopts a three-section detachable structure of "top cover 21, side shell 22, and bottom plate 1". Specifically, the top cover 21 is quickly fastened to the upper end face of the side shell 22 through a snap-fit ​​locking structure, and the bottom plate 1 is quickly fastened to the lower end face of the side shell 22 through a snap-fit ​​locking structure. In other feasible embodiments, nylon or ceramic screws are used for connection. The top shell has multiple threaded connection holes to accommodate special composite material screws, which can be used in different installation environments and avoids the introduction of additional eddy currents by metal screws. Conductive buffer layers are provided at the connection between the top cover plate 21 and the side housing 22, as well as at the connection between the bottom plate 1 and the side housing 22. Conductive rubber strips can be used. Under locking pressure, the cover plate, side housing 22, and bottom plate 1 form a continuous conductive path, ensuring the grounding and electromagnetic shielding integrity of the entire machine. In addition, the four corners of the side housing 22 are all set as rounded corners with a radius of not less than 5mm, reducing the convergence effect of eddy currents at the corners and further reducing eddy current losses.

[0029] Furthermore, all the slot structures 3 are physically separated from the edge of the outer shell 2 at both ends along the length direction, specifically by maintaining a solid separation of not less than 2mm, forming an "island-like" slot island, completely cutting off the closed-loop path of eddy current in the circumference of the shell, and avoiding edge current backflow. The slot structure 3 includes: several first slots 31 opened on the top cover plate 21, the first slots 31 need to avoid the main magnetic flux path of the transformer to avoid affecting the normal magnetic circuit of the transformer; several second slots 32 and third slots 33 opened on the side shell 22, the second slots 32 and third slots 33 are respectively located on two opposite surfaces of the side shell 22 and are both vertically arranged.

[0030] Furthermore, when slotting the second slot 32 and the third slot 33, a hole for the primary winding input end is reserved on one slotted surface, and a hole for the secondary winding output end is reserved on the other slotted surface. Creepage distances are reserved at the input and output holes according to the voltage level. The windings are fixed with an epoxy resin skeleton and coated. In the slotting direction of the second slot 32 and the third slot 33, the eddy current direction is perpendicular to the magnetic field line direction. Therefore, the slots must be opened along the magnetic field line direction to maximize the cutting of the eddy current path and disperse the eddy current density, thereby reducing eddy current losses. The second slot 32 and the third slot 33 adopt an asymmetrical slotting design. The width of the second slot 32 is greater than the width of the third slot 33, and the ratio of the remaining area of ​​the two opposite slotted surfaces of the side shell 22 is not less than 1.5:1. This differentiated cross-section further disperses the eddy current density and suppresses local overheating. The slots of the second slot 32 and the third slot 33 are filled with a thermally conductive insulating filler layer, balancing heat dissipation and mechanical strength.

[0031] Simulation experiments further effectively demonstrated that the encapsulation shell disclosed in this application for high-power high-frequency transformers can reduce eddy current losses and accelerate heat dissipation. Specifically, such as... Figure 3 As shown, a high-frequency transformer constructed using ANSYS Maxwell electromagnetic simulation software is presented. The transformer's core consists of an EE-type interlocking structure composed of a top E-type magnet 41 and a bottom E-type magnet 42. Both the top E-type magnet 41 and the bottom E-type magnet 42 have a cylindrical central post and two side posts. The central post can be used to wind the primary coil 51 and the secondary coil 61, both of which have tapped end faces. This high-frequency transformer features good magnetic circuit closure, low leakage flux, and an adjustable core gap 43. Its moderate window area provides a large magnetic flux, making it suitable for multi-winding, high-turns-ratio designs, similar to transformers in server power supplies and industrial frequency converters. Its structure enables efficient energy coupling and electrical isolation.

[0032] After the high-frequency transformer model is built, the material properties of components such as the magnetic core and coils are precisely set according to the transformer's operating conditions. For example, the magnetic core is made of amorphous alloy material with high permeability, and its relative permeability is set to 5000; the primary coil 51 and the secondary coil 61 are made of copper, and the conductivity is set to 5.8×107 S / m. At the same time, simulation parameters are set reasonably, including excitation source type, frequency, boundary conditions, etc.

[0033] like Figures 4-7 As shown, after completing the parameter setting process: first, a planar air domain 71 is established, the positions of the primary winding endpoint 511 and the secondary winding endpoint 611 are determined, the magnetic field simulation calculation program is started, the distribution of magnetic field lines around the transformer is obtained, and the planar magnetic field vector distribution 81 and the planar electric field vector distribution 82 are recorded; then, a three-dimensional composite material domain 72 is created, the simulation parameters are adjusted, and the three-dimensional magnetic field vector distribution 91 and the three-dimensional electric field vector distribution 92 are obtained. Through field strength numerical comparison and magnetic field line trajectory tracking, the high-intensity area and weak area of ​​the magnetic field inside the transformer, as well as the direction, convergence and divergence law of the magnetic field lines, are clearly defined. When using existing encapsulation shells and the encapsulation shell designed in this application to encapsulate this high-frequency transformer, as... Figure 8 and Figure 9 Temperature simulations show that, under the same operating conditions, when the high-frequency transformer is encapsulated in an existing enclosure, the surface temperature difference of the enclosure is large and local heat is concentrated, resulting in slow heat dissipation and high eddy current losses. However, when the high-frequency transformer is encapsulated in the enclosure described in this application, the surface temperature of the enclosure is significantly reduced and the heat distribution is relatively uniform, resulting in faster heat dissipation and thus reducing eddy current losses.

[0034] It should be understood that expressions such as "comprising" and "may include" as used in this application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In this application, terms such as "comprising" and / or "having" may be interpreted as indicating a specific characteristic, number, operation, constituent element, component, or combination thereof, but should not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0035] It should be understood that the terms “center,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “inner,” “outer,” “clockwise,” “counterclockwise,” “axial,” “radial,” and “circumferential” indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0036] Furthermore, 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. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0037] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0038] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A packaging shell for a high-power high-frequency transformer, characterized in that, It includes a base plate (1) and an outer shell body (2). The outer shell body (2) is detachably installed on the upper surface of the base plate (1). The interior of the outer shell body (2) is provided with a cavity for accommodating a high-frequency transformer. The top and side walls of the outer shell body (2) are provided with several slot structures (3). The cavity and all the slot structures (3) are filled with a thermally conductive and insulating filling layer.

2. The packaging shell for a high-power high-frequency transformer as described in claim 1, characterized in that, Both ends of several of the groove structures (3) along the length direction are physically separated from the edge of the outer shell body (2).

3. The packaging shell for a high-power high-frequency transformer as described in claim 1, characterized in that, The outer shell body (2) includes a top cover plate (21) and a side shell (22). The side shell (22) is a square shell structure with openings at both the top and bottom. The top cover plate (21) and the bottom plate (1) are detachably connected to the upper and lower end faces of the side shell (22), respectively.

4. The packaging shell for a high-power high-frequency transformer as described in claim 3, characterized in that, Conductive buffer layers are provided at the connection between the top cover plate (21) and the side shell (22) and at the connection between the bottom plate (1) and the side shell (22).

5. The packaging shell for a high-power high-frequency transformer as described in claim 3, characterized in that, The four corners of the side shell (22) are all set as rounded corners with a radius of not less than 5mm.

6. The packaging shell for a high-power high-frequency transformer as described in claim 3, characterized in that, The groove structure (3) includes: A plurality of first grooves (31) are formed on the top cover plate (21); A plurality of second grooves (32) and third grooves (33) are formed on the side housing (22); the second grooves (32) and third grooves (33) are respectively located on two opposite surfaces of the side housing (22).

7. The encapsulation housing for a high-power high-frequency transformer as described in claim 6, characterized in that, The width of the second groove (32) is greater than the width of the third groove (33).

8. The packaging shell for a high-power high-frequency transformer as described in claim 1, characterized in that, The portion of the upper surface of the base plate (1) located within the accommodating cavity is coated with thermally conductive silicone grease.

9. The packaging shell for a high-power high-frequency transformer as described in claim 1, characterized in that, The projected area of ​​the base plate (1) in the vertical direction is larger than the projected area of ​​the outer shell body (2), and mounting holes (11) are provided at the four corners of the base plate (1).

10. A packaging shell for a high-power high-frequency transformer as described in any one of claims 1-9, characterized in that, The outer shell body (2) is an aluminum-based silicon carbide metal-based composite component.

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