High-frequency large-current planar transformer
By staggering the primary windings and connecting the secondary windings in parallel in a planar transformer, combined with Litz wire connections and insulating film, the temperature rise problems caused by high current application at high frequencies and the skin effect are solved, achieving an efficient design of high-frequency, high-current planar transformers.
Patent Information
- Application Number
- CN202422535492.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-18
- Publication Date
- 2025-10-14
- Estimated Expiration
- 2034-10-18
AI Technical Summary
Existing planar transformers are difficult to implement in high-frequency designs for high-current applications, and there is a temperature rise problem caused by the skin effect.
A high-frequency, high-current planar transformer is designed. The primary winding and the secondary winding are arranged end to end in a staggered manner, connected in parallel through output vias, combined with Litz wire connection, the number of parallel windings and the via radius are increased, and the insulation level is improved by using insulating film.
It significantly improves the current capacity at high frequencies, solves the temperature rise problem caused by the skin effect, has a compact structure, is easy to process, and is suitable for new energy vehicles and photovoltaic energy storage.
Smart Images
Figure CN223436401U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field related to switching power supply devices, and more specifically, relates to a high-frequency and high-current planar transformer. Background Art
[0002] In order to improve the power density of power supply products and reduce the volume of magnetic components, the traditional wire-wound transformer is transformed into a planar transformer, which greatly reduces the height of the magnetic components and increases the window utilization area.
[0003] However, further research revealed that existing planar transformers typically connect to the PCB board via connectors after vias are punched into the PCB. The current that can flow through the device is related to the number of vias and the power supply frequency. In this case, the skin effect on the connector becomes more important at higher frequencies, making it difficult for existing planar transformers to achieve high current applications in high-frequency designs. Utility Model Content
[0004] In response to one or more of the above-mentioned defects or needs of the prior art, the present invention provides a high-frequency, high-current planar transformer, which fully combines the structural characteristics and special needs of the planar transformer, and through re-examination and improvement of its overall structural composition, can realize high-current application in high-frequency design and effectively reduce the skin effect on the plug-in.
[0005] To achieve the above objectives, the present invention provides a high-frequency, high-current planar transformer. The planar transformer includes a magnetic core and a PCB assembly mounted on the magnetic core. The planar transformer is characterized by:
[0006] The PCB assembly includes a primary winding PCB and a secondary winding PCB, wherein the primary winding PCBs are stacked in multiple layers and connected in parallel through output vias to form a primary winding, and the secondary winding PCBs are stacked in multiple layers and connected in parallel through output vias to form a secondary winding, and the primary winding and the secondary winding are arranged in an end-to-end staggered manner;
[0007] In addition, the outlet of the primary winding PCB is provided with a first half of vias, and the first Litz wire is installed through these first half of vias; the outlet of the secondary winding PCB is provided with a second half of vias, and the second Litz wire is installed through these second half of vias.
[0008] As a further preferred embodiment of the present invention, an insulating film is provided between the magnetic core, the primary winding and the secondary winding.
[0009] As a further preferred embodiment of the present invention, the Litz wire is installed by welding.
[0010] As a further preferred embodiment of the present invention, the primary winding PCB and the secondary winding PCB both have four or more layers.
[0011] As a further preferred embodiment of the present invention, the number of the primary winding PCBs and the secondary winding PCBs connected in parallel can be adjusted according to demand.
[0012] As a further preferred embodiment of the present invention, the above-mentioned planar transformer is used in new energy vehicles, photovoltaic energy storage or other isolated switching power supplies.
[0013] In general, the above technical solutions conceived by the present invention have the following technical advantages compared with the existing technology:
[0014] (1) The present invention addresses the difficulty in designing high-frequency, high-current planar transformers and has conducted targeted research and improvements on their overall structural composition and specific configuration. The primary winding and the secondary winding are stacked end to end, and the PCBs of each winding are connected in parallel through output vias. This significantly improves the current capability even at high frequencies. Furthermore, by utilizing Litz wire for external connection and improving the connection method, the application of high currents can be further ensured.
[0015] (2) The planar transformer of the utility model has a compact structure and is easy to process. In use, the overcurrent capacity can be further increased by increasing the number of parallel connections of the primary winding and the secondary winding and enlarging the via radius on the PCB board, which can improve the adaptability under various working conditions. At the same time, it effectively solves the temperature rise problem caused by the current skin effect at high frequency, and thus has good practical value and application prospects. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 This is a structural stereogram of a planar transformer provided in a preferred embodiment of the present application;
[0017] Figure 2 yes Figure 1 The schematic diagram of the primary side winding PCB shown in FIG;
[0018] Figure 3 yes Figure 1 The schematic diagram of the secondary winding PCB shown in FIG;
[0019] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:
[0020] 1-primary winding PCB; 2-secondary winding PCB; 3-magnetic core; 4-insulating film; 5-Litz wire; 101-first half of the via; 102-connection between the Litz wire and the PCB; 201-second half of the via; 202-connection between the Litz wire and the PCB. DETAILED DESCRIPTION
[0021] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.
[0022] It should be understood that expressions such as "include" and "may include" 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 "include" and / or "have" may be interpreted as indicating a specific characteristic, number, operation, constituent element, component, or combination thereof, but may not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.
[0023] It should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.
[0024] 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 the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.
[0025] In this application, unless otherwise specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they can refer to fixed connection, detachable connection, or integral connection; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.
[0026] Figure 1 This is a structural stereogram of the planar transformer provided by the preferred embodiment of the present application. Figure 1 To explain the present invention in more detail.
[0027] Referring to Figure 1 The planar transformer comprises a magnetic core 3 and a PCB set sleeved on the magnetic core 3, and the arrangement mode of the PCB set is particularly improved.
[0028] Specifically, the PCB set comprises a primary winding PCB 1 and a secondary winding PCB 2, wherein the primary winding PCB 1 is multi-layered and stacked and is connected in parallel through output vias to form a primary winding, i.e., a primary winding group, the secondary winding PCB 2 is multi-layered and stacked and is connected in parallel through output vias to form a secondary winding, i.e., a secondary winding group, and the primary winding group and the secondary winding group are arranged in an alternating manner.
[0029] In addition, first half vias 101 are formed at the wire outlets of the primary winding PCB 1, and first Litz wires are correspondingly installed through the first half vias 101; second half vias 201 are formed at the wire outlets of the secondary winding PCB, and second Litz wires are correspondingly installed through the second half vias 201.
[0030] More specifically, Figure 1 A transformer with a center tap is shown in FIG. 1, wherein the primary winding PCB and the secondary winding PCB are alternately stacked on the magnetic core, the primary winding PCB is connected in parallel through output vias, and the secondary winding PCB is connected in parallel through output vias, so that the current capacity can be significantly improved even at high frequencies; in addition, an insulating film 4 can be added between the magnetic core and the secondary winding group and the primary winding group to improve the insulation level.
[0031] In addition, a plurality of half vias are formed at the wire outlets of the primary winding PCB and the secondary winding PCB, and Litz wires 5 are correspondingly installed by welding, so that the overcurrent capacity can be increased by increasing the number of the primary winding group PCB and the secondary winding group PCB connected in parallel and expanding the via radius on the PCB card in actual use, and finally the Litz wires are connected with a power circuit.
[0032] In summary, the planar transformer according to the present application is improved in the overall structure and the specific arrangement mode to solve the problem of designing a high-frequency and high-current planar transformer, so that the current capacity can be significantly improved even at high frequencies; the planar transformer has a compact structure, is convenient to process, and can flexibly adjust the overcurrent capacity according to requirements in use, effectively solves the problem of temperature rise caused by the skin effect of current at high frequencies, and is particularly suitable for new energy vehicles, photovoltaic energy storage, and other isolated switching power supply application occasions, and has good practical value and application prospect.
[0033] Those skilled in the art can understand that the above description is only the preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.
Claims
1. A high-frequency, high-current planar transformer comprising a magnetic core and a PCB assembly mounted on the magnetic core, characterized in that: The PCB assembly includes a primary winding PCB and a secondary winding PCB, wherein the primary winding PCBs are stacked in multiple layers and connected in parallel through output vias to form a primary winding, and the secondary winding PCBs are stacked in multiple layers and connected in parallel through output vias to form a secondary winding, and the primary winding and the secondary winding are arranged in an end-to-end staggered manner; In addition, the outlet of the primary winding PCB is provided with a first half of vias, and the first Litz wire is installed through these first half of vias; the outlet of the secondary winding PCB is provided with a second half of vias, and the second Litz wire is installed through these second half of vias.
2. The planar transformer according to claim 1, wherein: An insulating film is provided between the magnetic core, the primary winding and the secondary winding.
3. The planar transformer according to claim 1 or 2, wherein: The litz wire is installed by welding.
4. The planar transformer according to claim 1 or 2, wherein: The primary winding PCB and the secondary winding PCB both have more than four layers.
5. The planar transformer according to claim 1 or 2, wherein: The number of primary winding PCBs and secondary winding PCBs connected in parallel can be adjusted according to demand.