Transformer with embedded water cooling system having magnetic flux leakage guiding structure and heat dissipation method
By introducing a C-type water-cooled plate and a ferrite magnetic chip leakage flux conduction structure into the high-frequency transformer, the problem of eddy current loss caused by high-frequency leakage flux is solved, achieving efficient heat dissipation and improved system reliability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XI AN JIAOTONG UNIV
- Filing Date
- 2026-03-31
- Publication Date
- 2026-06-12
AI Technical Summary
In high-frequency transformers, traditional metal water cooling systems fail to effectively avoid high-frequency leakage flux, resulting in severe eddy current losses. Non-metallic water cooling systems, on the other hand, have low thermal conductivity and poor reliability, making it difficult to meet the heat dissipation requirements of high-power high-frequency transformers.
The leakage flux guiding structure, which consists of a C-type water-cooled plate and a ferrite magnetic chip, guides the high-frequency leakage flux to the main magnetic core through magnetic circuit design, reduces the leakage flux density that passes vertically through the water-cooled plate, and uses the coolant circulation to remove heat.
It significantly reduces eddy current losses, improves heat dissipation efficiency, enhances system reliability, avoids the metal water-cooled plate becoming a heat source, and ensures the long-term stable operation of the high-frequency transformer.
Smart Images
Figure CN122202002A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of high-frequency transformer cooling technology, and in particular to an embedded water cooling system, transformer and heat dissipation method with a leakage flux conduction structure. Background Technology
[0002] In megawatt-level, high-frequency applications, the heat dissipation design of large-capacity high-frequency transformers has become one of the core factors restricting their long-term reliability and overall efficiency. Due to the significant enhancement of core losses and the skin effect and proximity effect of windings under high-frequency operating conditions, coupled with the pursuit of extremely high power density by high-power high-frequency transformers, the heat load per unit space increases exponentially, far exceeding the heat load of traditional power frequency transformers. At the same time, to ensure insulation strength, insulation materials are generally required for potting. If the internal heat cannot be effectively dissipated, the internal temperature will rise sharply, accelerating the aging of the insulation materials and seriously affecting the insulation life and operational safety.
[0003] To address this issue, the industry has introduced various heat dissipation methods, including natural cooling, forced air cooling, and water cooling. Natural cooling is limited by the heat dissipation area and air convection efficiency, and is only suitable for low power density scenarios. Forced air cooling cannot effectively dissipate the heat inside the transformer, and is gradually developing towards water cooling technology that penetrates directly into the transformer. However, high-frequency transformers have extremely strong high-frequency leakage flux. If conventional metal cooling plates or water cooling systems are placed directly inside the high-frequency transformer, the high-frequency alternating leakage flux that passes vertically through the metal surface will induce a large amount of eddy current inside the metal, resulting in severe leakage eddy current losses.
[0004] CN220252982U discloses a high-frequency transformer with a water-cooled circulation system structure. This structure directly connects a water cooler consisting of multiple water-cooled pipes and circulation pipes to the outside of the coil winding inside the sealed shell, and uses an internal fan for heat dissipation. However, this solution directly wraps a large area of metal water-cooled pipes around the high leakage magnetic field area outside the coil without any effective guidance, avoidance or shielding of the high-frequency leakage magnetic flux. Under high-power high-frequency operating conditions, the strong alternating leakage magnetic flux will directly pass through these metal water-cooled pipes, inducing huge high-frequency eddy currents on the metal pipe walls. This will not only cause great additional eddy current losses and reduce the overall efficiency of the transformer, but also cause the metal water-cooled pipes themselves to become new heat sources, and may even cause local boiling of the cooling medium inside the pipes, seriously threatening the safe and stable operation of the equipment. CN114551048A discloses a heat dissipation system for a large-capacity high-frequency transformer with embedded ceramic heat pipes. This scheme uses heat pipes made of ceramic material to be mounted on the primary and secondary side frames, which are also made of ceramic material. The heat pipes utilize the heat transfer fluid inside to perform phase change circulation heat transfer. This method takes advantage of the high insulation and non-ferromagnetic properties of ceramic materials, fundamentally avoiding the problem of metal eddy current loss generated in the tube shell in the high-frequency leakage magnetic field. However, ceramic materials have low thermal conductivity, making it difficult to effectively transfer heat to the heat transfer fluid. On the other hand, the processing of ceramic materials is extremely complex and costly. At the same time, ceramics themselves are relatively brittle. Under the long-term electromagnetic vibration and thermal stress impact of the transformer, the embedded ceramic tube shell is prone to micro-cracks or even rupture, posing a very serious risk of coolant leakage. The reliability in industrial applications is difficult to guarantee.
[0005] For large-capacity high-frequency transformers encapsulated with insulating materials, traditional air cooling and forced air cooling solutions are limited by the heat dissipation area of the equipment surface and the external air convection efficiency. This makes it difficult to effectively dissipate heat into the core heat-generating areas inside the transformer, which can easily lead to a large accumulation of internal heat and accelerate insulation aging.
[0006] While directly installing a conventional metal water-cooling system inside the transformer leverages the high efficiency of liquid cooling, it fails to effectively avoid or guide high-frequency leakage flux. This leads to high-frequency eddy current losses induced in the metal tube walls, reducing the overall transformer efficiency and easily causing localized boiling of the internal cooling medium, jeopardizing equipment safety. Using non-metallic insulating materials such as ceramics for internal heat pipes fundamentally avoids the problem of metal eddy current losses, but the thermal conductivity of ceramics is far lower than that of metals, severely limiting rapid heat dissipation. Furthermore, ceramics are brittle and prone to cracking, resulting in extremely low long-term reliability in industrial applications.
[0007] The information disclosed in the background section is only intended to enhance the understanding of the background of the present invention, and therefore may contain information that does not constitute prior art known to those skilled in the art. Summary of the Invention
[0008] To address the shortcomings or defects of the existing technology, an embedded water-cooling system, transformer, and heat dissipation method with a leakage magnetic flux guiding structure are provided. This ensures efficient water cooling inside the high-power, high-frequency transformer while overcoming the high-frequency leakage magnetic flux eddy current heating bottleneck inherent in traditional embedded metal water-cooling devices. It suppresses leakage magnetic flux eddy current losses on the surface of the metal water-cooling plate from a physical source, while avoiding the inherent risks of slow heat conduction, fragility, and leakage in non-metallic water-cooling devices.
[0009] The objective of this invention is achieved through the following technical solutions.
[0010] An embedded water-cooling system with a magnetic flux leakage conduction structure includes:
[0011] The C-type water-cooled plate is embedded in the gap area between the secondary winding and the main magnetic core of the high-frequency transformer to directly contact and dissipate the heat of the gap area.
[0012] The leakage magnetic flux guiding structure is composed of several ferrite magnetic chips spliced together. The several ferrite magnetic chips include at least one first magnetic chip and at least one second magnetic chip. One end of the second magnetic chip is directly and tightly connected to the main magnetic core to form a low magnetic reluctance magnetic path. The first magnetic chip is set close to the C-shaped water-cooling plate and maintains a preset distance from the main magnetic core or is isolated from the main magnetic core through a high magnetic reluctance medium. The leakage magnetic flux guiding structure is configured to guide the high-frequency leakage magnetic flux generated during the operation of the high-frequency transformer to preferentially enter the second magnetic chip and flow to the main magnetic core, so as to reduce the leakage magnetic flux density perpendicularly passing through the C-shaped water-cooling plate, thereby suppressing the eddy current loss in the C-shaped water-cooling plate.
[0013] In the embedded water-cooling system with a magnetic leakage conduction structure, the several ferrite magnetic chips are bonded together with an adhesive to form an integral structure.
[0014] In the embedded water-cooling system with a leakage magnetic conduction structure, the ferrite magnetic chips that are in close contact with the C-shaped water-cooling plate in terms of spatial layout are all the first magnetic chips except for the second magnetic chip; the second magnetic chip serves as a magnetic flux convergence point, and its geometry extends to achieve gapless contact with the end face or side face of the main magnetic core.
[0015] In the embedded water-cooling system with leakage magnetic conduction structure, the C-shaped water-cooling plate has a coolant flow channel inside, and the direction of the coolant flow channel matches the heat distribution of the secondary winding.
[0016] In the embedded water-cooling system with a leakage magnetic conduction structure, the C-type water-cooling plate is made of non-ferromagnetic metal or weakly magnetic metal, and the ferrite magnetic chip is made of manganese-zinc ferrite or nickel-zinc ferrite.
[0017] In the embedded water-cooling system with a leakage magnetic conduction structure, the preset distance or high magnetic resistance medium setting makes the magnetic resistance of the magnetic circuit from the first magnetic chip to the main magnetic core greater than the magnetic resistance of the magnetic circuit from the second magnetic chip to the main magnetic core, and the magnetic resistance ratio is at least 5:1.
[0018] In the embedded water-cooling system with leakage flux guiding structure, the high-frequency transformer is completely wrapped with insulating potting material; the C-shaped water-cooling plate and the leakage flux guiding structure are both pre-placed inside the insulating potting material and fixed between the secondary winding and the main magnetic core before the potting process is completed.
[0019] A high-frequency transformer includes:
[0020] Main magnetic core;
[0021] The primary winding and the secondary winding are wound on the main magnetic core;
[0022] An insulating potting layer is used to encapsulate the main magnetic core, primary winding, and secondary winding as a whole.
[0023] And an embedded water-cooling system with a magnetic flux leakage conduction structure;
[0024] The C-shaped water-cooling plate of the embedded water-cooling system is embedded in the gap between the secondary winding and the main magnetic core, and the leakage magnetic flux guiding structure is located between the C-shaped water-cooling plate and the return magnetic path of the insulating potting layer or the main magnetic core.
[0025] In the high-frequency transformer, the embedded water-cooling system is also connected to an external circulation pipeline for providing constant-temperature coolant to the C-shaped water-cooling plate. When the transformer is running under rated high-frequency conditions, the normal leakage flux density on the surface of the C-shaped water-cooling plate is reduced by more than 90% compared to when the structure is not set, and the eddy current loss induced by the leakage flux is reduced by more than 90%.
[0026] A high-frequency transformer heat dissipation method based on an embedded water-cooling system with a leakage flux conduction structure includes:
[0027] Step S1: During the high-frequency transformer assembly stage, the C-type water-cooled plate is positioned and installed in the gap area between the secondary winding and the main magnetic core;
[0028] Step S2: Assemble a leakage magnetic conduction structure composed of multiple ferrite magnetic chips on the outer surface of the C-type water-cooled plate, ensuring that at least one of the second magnetic chips is in direct physical contact with the main magnetic core to construct a low magnetic resistance return channel.
[0029] Step S3: Perform insulation potting to solidify the embedded water cooling system and the transformer body into a whole;
[0030] Step S4: During the high-frequency operation of the transformer, the high-frequency leakage flux that originally passed vertically through the metal water-cooling plate is forcibly guided to the second magnetic chip and into the main magnetic core by utilizing the magnetic resistance difference characteristics of the leakage flux guiding structure.
[0031] Step S5: The heat generated by the secondary winding is carried away by the coolant circulation in the C-type water-cooled plate, while maintaining the low temperature operation of the water-cooled plate itself under low eddy current loss conditions.
[0032] Compared with existing technologies, the beneficial effects of this invention are as follows: Compared with existing technologies that directly surround the winding with metal water-cooling pipes, this invention does not allow alternating magnetic flux to penetrate the metal pipe wall. Instead, it constructs a leakage flux guiding structure, actively changing the leakage flux path, which greatly reduces the leakage flux eddy current loss of the embedded metal cooling device and prevents the water-cooling plate from becoming a secondary heat source. Compared with existing technologies that use non-metallic heat pipes, this invention retains conventional metals with high strength and high thermal conductivity as the water-cooling plate substrate. Not only does its heat conduction efficiency far exceed that of ceramic materials, but the metal material also possesses inherent mechanical toughness and fatigue resistance, easily resisting the electromagnetic mechanical vibration and alternating thermal stress impacts during the long-term operation of large-capacity high-frequency transformers. Compared with natural cooling and forced air cooling methods, this invention addresses the heat dissipation difficulties of high-frequency transformers encapsulated with insulating materials by directly embedding a C-shaped water-cooling plate in the heat dissipation bottleneck, namely between the secondary winding and the magnetic core, which can quickly dissipate heat from this area.
[0033] The description provided is merely an overview of the technical solution of this invention. In order to make the technical means of this invention clearer and more understandable, so that those skilled in the art can implement it according to the contents of the specification, and to make the described and other objects, features and advantages of this invention more obvious and understandable, specific embodiments of this invention are described below. Attached Figure Description
[0034] Various other advantages and benefits of the present invention will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. Furthermore, the same reference numerals denote the same parts throughout the drawings.
[0035] In the attached diagram:
[0036] Figure 1 A schematic diagram of an embedded water-cooling system with a magnetic flux leakage conduction structure;
[0037] Figure 2The diagram shows the leakage magnetic flux density on the surface of the water-cooled plate, where (a) is the front view of the structure without leakage magnetic flux, (b) is the side view of the structure without leakage magnetic flux, (c) is the front view of the structure with leakage magnetic flux, and (d) is the side view of the structure with leakage magnetic flux.
[0038] Figure 3 Eddy current density of water-cooled plate (A / m) 2 ) Schematic diagram, wherein (a) is a non-leakage magnetic conduction structure, and (b) is a leakage magnetic conduction structure;
[0039] Figure 4 The temperature field distribution diagrams are shown for different cooling methods, where (a) is natural cooling and (b) is an embedded water cooling system.
[0040] The present invention will be further explained below with reference to the accompanying drawings and embodiments. Detailed Implementation
[0041] Specific embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While specific embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.
[0042] It should be noted that certain terms are used in the specification and claims to refer to specific components. Those skilled in the art will understand that different terms may be used to refer to the same component. This specification and claims do not distinguish components based on differences in terminology, but rather on differences in function. The terms "comprising" or "including" used throughout the specification and claims are open-ended and should be interpreted as "comprising but not limited to." The following descriptions are preferred embodiments for carrying out the invention; however, these descriptions are for the purpose of understanding the general principles of the specification and are not intended to limit the scope of the invention. The scope of protection of this invention is determined by the appended claims.
[0043] To facilitate understanding of the embodiments of the present invention, the following will provide further explanation and description with reference to the accompanying drawings and several specific embodiments, and the accompanying drawings do not constitute a limitation on the embodiments of the present invention.
[0044] To better understand, such as Figures 1 to 4 As shown, an embedded water-cooling system with a magnetic flux leakage conduction structure includes:
[0045] The C-type water-cooled plate is embedded in the gap area between the secondary winding and the main magnetic core of the high-frequency transformer to directly contact and dissipate the heat of the gap area.
[0046] The leakage magnetic flux guiding structure is composed of several ferrite magnetic chips spliced together. The several ferrite magnetic chips include at least one first magnetic chip and at least one second magnetic chip. One end of the second magnetic chip is directly and tightly connected to the main magnetic core to form a low magnetic reluctance magnetic path. The first magnetic chip is set close to the C-shaped water-cooling plate and maintains a preset distance from the main magnetic core or is isolated from the main magnetic core through a high magnetic reluctance medium. The leakage magnetic flux guiding structure is configured to guide the high-frequency leakage magnetic flux generated during the operation of the high-frequency transformer to preferentially enter the second magnetic chip and flow to the main magnetic core, so as to reduce the leakage magnetic flux density perpendicularly passing through the C-shaped water-cooling plate, thereby suppressing the eddy current loss in the C-shaped water-cooling plate.
[0047] In a preferred embodiment of the embedded water-cooling system with a magnetic leakage conduction structure, the plurality of ferrite magnetic chips are bonded together with an adhesive to form an integral structure.
[0048] In a preferred embodiment of the embedded water-cooling system with a leakage magnetic conduction structure, all the ferrite magnetic chips that are in close contact with the C-shaped water-cooling plate in terms of spatial layout are the first magnetic chips except for the second magnetic chip; the second magnetic chip serves as a magnetic flux convergence point, and its geometry extends to achieve gapless contact with the end face or side face of the main magnetic core.
[0049] In a preferred embodiment of the embedded water-cooling system with a leakage magnetic flux guiding structure, the C-shaped water-cooling plate has a coolant flow channel inside, and the direction of the coolant flow channel matches the heat distribution of the secondary winding.
[0050] In a preferred embodiment of the embedded water-cooling system with a leakage magnetic conduction structure, the C-type water-cooling plate is made of a non-ferromagnetic metal or a weakly magnetic metal material, and the ferrite magnetic chip is made of manganese-zinc ferrite or nickel-zinc ferrite.
[0051] In a preferred embodiment of the embedded water-cooling system with a leakage magnetic conduction structure, the preset distance or high magnetic reluctance medium is set such that the magnetic reluctance of the magnetic circuit from the first magnetic chip to the main magnetic core is greater than the magnetic reluctance of the magnetic circuit from the second magnetic chip to the main magnetic core, and the magnetic reluctance ratio is at least 5:1.
[0052] In a preferred embodiment of the embedded water-cooling system with a leakage flux guiding structure, the high-frequency transformer is entirely encapsulated by an insulating potting material; the C-shaped water-cooling plate and the leakage flux guiding structure are both pre-placed inside the insulating potting material and fixed between the secondary winding and the main magnetic core before the potting process is completed.
[0053] A high-frequency transformer includes:
[0054] Main magnetic core;
[0055] The primary winding and the secondary winding are wound on the main magnetic core;
[0056] An insulating potting layer is used to encapsulate the main magnetic core, primary winding, and secondary winding as a whole.
[0057] And an embedded water-cooling system with a magnetic flux leakage conduction structure;
[0058] The C-shaped water-cooling plate of the embedded water-cooling system is embedded in the gap between the secondary winding and the main magnetic core, and the leakage magnetic flux guiding structure is located between the C-shaped water-cooling plate and the return magnetic path of the insulating potting layer or the main magnetic core.
[0059] In a preferred embodiment of the high-frequency transformer, the embedded water-cooling system is further connected to an external circulation pipeline for providing constant-temperature coolant to the C-shaped water-cooling plate; when the transformer is running under rated high-frequency conditions, the normal leakage flux density on the surface of the C-shaped water-cooling plate is reduced by more than 90% compared to when the structure is not provided, and the eddy current loss induced by the leakage flux is reduced by more than 90%.
[0060] A high-frequency transformer heat dissipation method based on an embedded water-cooling system with a leakage flux conduction structure includes:
[0061] Step S1: During the high-frequency transformer assembly stage, the C-type water-cooled plate is positioned and installed in the gap area between the secondary winding and the main magnetic core;
[0062] Step S2: Assemble a leakage magnetic conduction structure composed of multiple ferrite magnetic chips on the outer surface of the C-type water-cooled plate, ensuring that at least one of the second magnetic chips is in direct physical contact with the main magnetic core to construct a low magnetic resistance return channel.
[0063] Step S3: Perform insulation potting to solidify the embedded water cooling system and the transformer body into a whole;
[0064] Step S4: During the high-frequency operation of the transformer, the high-frequency leakage flux that originally passed vertically through the metal water-cooling plate is forcibly guided to the second magnetic chip and into the main magnetic core by utilizing the magnetic resistance difference characteristics of the leakage flux guiding structure.
[0065] Step S5: The heat generated by the secondary winding is carried away by the coolant circulation in the C-type water-cooled plate, while maintaining the low temperature operation of the water-cooled plate itself under low eddy current loss conditions.
[0066] In one embodiment, the C-shaped water-cooled plate is a metal plate.
[0067] In one embodiment, an embedded water-cooling system with a leakage flux guiding structure can remove heat by penetrating deep into the high-frequency transformer through a water-cooled plate. Simultaneously, the leakage flux guiding structure alters the leakage flux path, significantly reducing the leakage flux perpendicular to the metal water-cooled plate, thereby reducing eddy current losses generated by the leakage flux on the metal water-cooled plate. This achieves high heat dissipation efficiency with virtually no additional losses. A schematic diagram of its specific structure is shown below. Figure 1 As shown.
[0068] The present invention pertains to a typical high-frequency transformer, whose embedded water-cooling system mainly comprises two sets of C-shaped water-cooling plates and several ferrite magnetic chips. The core feature is that the embedded water-cooling plates are placed between the secondary winding and the magnetic core, forming a C-shape. For epoxy resin-encapsulated high-frequency transformers, this area is a concentrated heat region, making heat dissipation difficult. Therefore, embedding the water-cooling plates in this area can effectively dissipate the heat through the coolant. However, the leakage flux density is also relatively high here, and the alternating leakage flux will generate significant eddy currents on the surface of the metal water-cooling plates. Eddy current losses are generated. In areas with high leakage flux density, several ferrite magnetic chips can be placed close to the water-cooling plate, bonded together with ordinary adhesive. Except for three ferrite magnetic chips in close contact with the water-cooling plate, another ferrite magnetic chip is tightly connected to the core. Because the distance between the three ferrite magnetic chips in close contact with the water-cooling plate and the core is relatively large (i.e., the magnetic resistance is high), when leakage flux enters these three ferrite magnetic chips, it flows into the ferrite magnetic chip in close contact with the core, and then into the core, avoiding eddy current losses on the surface of the water-cooling plate. Unlike traditional solutions that directly connect metal water pipes or use non-metallic heat pipes, this method embeds a C-shaped metal water-cooling plate between the secondary winding and the core, where heat dissipation is most challenging. Simultaneously, a leakage flux guiding structure composed of multiple ferrite magnetic chips is arranged in areas with high leakage flux density, achieving a combination of efficient heat dissipation and low eddy current losses. The spatial layout creates a magnetic reluctance difference. Three ferrite magnetic chips, in close contact with the water-cooling plate, are farther from the core and have higher magnetic reluctance, while another ferrite magnetic chip is tightly connected to the core and has extremely low magnetic reluctance. This structure guides the high-frequency leakage flux, which would normally pass perpendicularly through the metal water-cooling plate, to the ferrite magnetic chip in close contact with the core, and then flows into the core, fundamentally cutting off the path for the leakage flux to induce high-frequency eddy currents on the surface of the water-cooling plate. By precisely locating the narrow hotspot area between the secondary winding and the core, and using a suitable C-shaped water-cooling plate for targeted cooling, combined with the leakage flux guidance structure, efficient heat extraction from the core heat-generating area inside the transformer is achieved without increasing the overall volume.
[0069] Frequency domain FE simulation was performed using the finite element simulation software COMSOL Multiphysics to compare the leakage flux density and eddy current density of the water-cooled plate with and without the aforementioned leakage flux conduction structure. First, the leakage flux density in the water-cooled plate region was analyzed, such as... Figure 2 As shown in the comparison, it can be seen that by adopting the leakage magnetic flux guiding structure proposed in this paper, the normal leakage magnetic flux density at the surface of the water-cooled plate is significantly reduced. Figure 3 As can be seen, with the leakage flux guiding structure, the eddy current density on the surface of the water-cooled plate is significantly reduced. Therefore, the leakage flux eddy current loss generated on the surface of the water-cooled plate is also significantly reduced. Assuming the primary winding current is 100A, it can be calculated that without the leakage flux guiding structure, the leakage flux eddy current loss generated on the surface of the water-cooled plate is about 36.86W, while with the leakage flux guiding structure, the leakage flux eddy current loss generated on the water-cooled plate is about 3.02W, which reduces the leakage flux eddy current loss by 92%.
[0070] To verify the effectiveness of the embedded water-cooling system in heat dissipation of a high-frequency transformer encapsulated with epoxy resin, temperature field simulation was performed using the finite element simulation software COMSOL Multiphysics. Assuming the coolant in the water-cooled plate was maintained at 40°C, the temperature field results are as follows: Figure 4 As shown, comparing the two cooling methods, the highest internal temperature can reach 128℃ with natural cooling, while the highest internal temperature drops to 58℃ after the embedded water cooling system is installed, proving the effectiveness of the embedded water cooling system.
[0071] Furthermore, this invention constructs a flux-selective "low-resistance highway" within the high-frequency transformer, fundamentally resolving the contradiction between efficient metal heat conduction and high-frequency eddy current losses. Specifically, when the high-frequency transformer is operating, extremely high-density alternating leakage flux perpendicular to the winding plane is generated between the secondary winding and the main magnetic core. Without a guiding structure, these magnetic lines of force would pass directly and perpendicularly through the embedded C-shaped metal water-cooling plate. According to Faraday's law of electromagnetic induction, this would induce strong closed eddy currents within the highly conductive metal plate wall, leading to severe I²R Joule heat loss. Consequently, the water-cooling plate not only fails to dissipate heat but also becomes a new internal heat source, even causing localized boiling of the coolant. By tightly arranging a conductive structure composed of multiple ferrite magnetic chips on the outside of the metal water-cooling plate, and utilizing the principle of parallel magnetic circuits to create a significant difference in magnetic reluctance: the "second magnetic chip," which is directly and tightly connected to the main magnetic core, forms an extremely low magnetic reluctance path (equivalent to short-circuiting the magnetic circuit), while the "first magnetic chip," which is only attached to the water-cooling plate but not directly connected to the main magnetic core, forms a relatively high magnetic reluctance path. Since alternating magnetic flux always tends to close along the path of least magnetic reluctance, most of the high-frequency leakage flux that would originally penetrate the metal plate is "attracted" and forced to change direction after entering the ferrite layer, flowing directly back to the main magnetic core along the low-magnetic-resistance second magnetic chip, thus "bypassing" the metal water-cooling plate. This mechanism delivers three significant technical benefits: Eddy current source elimination: Simulation data shows that this structure reduces the normal leakage flux density perpendicularly passing through the surface of the metal water-cooled plate by over 90%, thereby drastically reducing the induced eddy current density and resulting eddy current losses within the metal plate from approximately 36.86W to 3.02W (a 92% reduction), completely eliminating the potential for self-heating of the metal water-cooled plate. Maximized thermal conductivity: Due to the elimination of eddy current heating limitations, this solution allows the use of conventional metal materials (such as copper or aluminum) with thermal conductivity far exceeding that of ceramics (typically >200W / m·K vs <30W / m·K) to fabricate the water-cooled plate. Combined with an embedded layout that directly contacts the heat source, the highest temperature in the core area inside the transformer is significantly reduced from 128℃ under natural cooling to 58℃, resulting in a significant improvement in heat dissipation efficiency. Enhanced structural reliability: Compared to the fragile ceramic heat pipe solution, this solution retains the excellent mechanical toughness and fatigue resistance of the metal material, which can withstand the electromagnetic vibration and thermal stress impact during the operation of the high-frequency transformer for a long time. It avoids the risk of coolant leakage caused by material cracking, and greatly improves the long-term operational reliability and safety of megawatt-level high-frequency transformers under harsh operating conditions.
[0072] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.
[0073] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.
Claims
1. An embedded water-cooling system with a magnetic flux leakage conduction structure, characterized in that, It includes, The C-type water-cooled plate is embedded in the gap area between the secondary winding and the main magnetic core of the high-frequency transformer to directly contact and dissipate the heat of the gap area. The leakage magnetic flux guiding structure is composed of several ferrite magnetic chips spliced together. The several ferrite magnetic chips include at least one first magnetic chip and at least one second magnetic chip. One end of the second magnetic chip is directly and tightly connected to the main magnetic core to form a low magnetic reluctance magnetic path. The first magnetic chip is set close to the C-shaped water-cooling plate and maintains a preset distance from the main magnetic core or is isolated from the main magnetic core through a high magnetic reluctance medium. The leakage magnetic flux guiding structure is configured to guide the high-frequency leakage magnetic flux generated during the operation of the high-frequency transformer to preferentially enter the second magnetic chip and flow to the main magnetic core, so as to reduce the leakage magnetic flux density perpendicularly passing through the C-shaped water-cooling plate, thereby suppressing the eddy current loss in the C-shaped water-cooling plate.
2. The embedded water-cooling system with a magnetic flux leakage conduction structure as described in claim 1, characterized in that, Preferably, the plurality of ferrite magnetic chips are bonded together with an adhesive to form an integral structure.
3. The embedded water-cooling system with a magnetic flux leakage conduction structure as described in claim 1, characterized in that, In terms of spatial layout, the ferrite magnetic chips that are in close contact with the C-shaped water-cooled plate are all the first magnetic chips except for the second magnetic chip; the second magnetic chip serves as a magnetic flux convergence point, and its geometry extends to achieve gapless contact with the end face or side face of the main magnetic core.
4. The embedded water-cooling system with a magnetic flux leakage conduction structure as described in claim 1, characterized in that, The C-shaped water-cooled plate has a coolant flow channel inside, and the direction of the coolant flow channel matches the heat distribution of the secondary winding.
5. The embedded water-cooling system with a magnetic flux leakage conduction structure as described in claim 1, characterized in that, The C-type water-cooled plate is made of non-ferromagnetic metal or weakly magnetic metal, and the ferrite magnetic chip is made of manganese-zinc ferrite or nickel-zinc ferrite.
6. The embedded water-cooling system with a magnetic flux leakage conduction structure as described in claim 1, characterized in that, The preset distance or high magnetoresistance medium setting ensures that the magnetic reluctance of the magnetic circuit from the first magnetic chip to the main magnetic core is greater than that from the second magnetic chip to the main magnetic core, with a reluctance ratio of at least 5:
1.
7. The embedded water-cooling system with a magnetic flux leakage conduction structure as described in claim 1, characterized in that, The high-frequency transformer is entirely encapsulated with insulating potting material; the C-shaped water-cooling plate and the leakage flux guiding structure are both pre-placed inside the insulating potting material and fixed between the secondary winding and the main magnetic core before the potting process is completed.
8. A high-frequency transformer, characterized in that, include: Main magnetic core; The primary winding and the secondary winding are wound on the main magnetic core; An insulating potting layer is used to encapsulate the main magnetic core, primary winding, and secondary winding as a whole. And an embedded water-cooling system with a magnetic flux leakage conduction structure as described in any one of claims 1 to 7; The C-shaped water-cooling plate of the embedded water-cooling system is embedded in the gap between the secondary winding and the main magnetic core, and the leakage magnetic flux guiding structure is located between the C-shaped water-cooling plate and the return magnetic path of the insulating potting layer or the main magnetic core.
9. The high-frequency transformer as described in claim 8, characterized in that, The embedded water cooling system is also connected to an external circulation pipeline for providing constant temperature coolant to the C-shaped water cooling plate. When the transformer is running under rated high-frequency conditions, the normal leakage flux density on the surface of the C-shaped water cooling plate is reduced by more than 90% compared to when the structure is not set, and the eddy current loss induced by the leakage flux is reduced by more than 90%.
10. A method for heat dissipation of a high-frequency transformer based on an embedded water-cooling system with a leakage magnetic flux conduction structure according to any one of claims 1-7, characterized in that, It includes, Step S1: During the high-frequency transformer assembly stage, the C-type water-cooled plate is positioned and installed in the gap area between the secondary winding and the main magnetic core; Step S2: Assemble a leakage magnetic conduction structure composed of multiple ferrite magnetic chips on the outer surface of the C-type water-cooled plate, ensuring that at least one of the second magnetic chips is in direct physical contact with the main magnetic core to construct a low magnetic resistance return channel. Step S3: Perform insulation potting to solidify the embedded water cooling system and the transformer body into a whole; Step S4: During the high-frequency operation of the transformer, the high-frequency leakage flux that originally passed vertically through the metal water-cooling plate is forcibly guided to the second magnetic chip and into the main magnetic core by utilizing the magnetic resistance difference characteristics of the leakage flux guiding structure. Step S5: The heat generated by the secondary winding is carried away by the coolant circulation in the C-type water-cooled plate, while maintaining the low temperature operation of the water-cooled plate itself under low eddy current loss conditions.