Air-core high-frequency transformer and modeling method thereof

Abstract

The application belongs to the field of high-frequency transformers, and particularly relates to a kind of air-core high-frequency transformers and its modeling method, aiming at solving the problems of large volume, high weight and low power density of existing high-frequency transformers.The application comprises: a first secondary winding, a first primary winding, a second primary winding and a second secondary winding, an insulating layer 1 is arranged between the first secondary winding and the first primary winding, and an insulating layer 2 is arranged between the second primary winding and the second secondary winding; the first primary winding and the second primary winding are connected in series, and N-turn coils are wound clockwise in a single layer from top to bottom between the incoming and outgoing ends of the first primary winding and the second primary winding; the first secondary winding and the second secondary winding are connected in series, and M-turn coils are wound clockwise in a single layer from top to bottom between the incoming and outgoing ends of the first secondary winding and the second secondary winding.The application adopts a non-magnetic core design, which can effectively reduce the weight of the high-frequency transformer and improve the power density.

Description

Technical Field

[0001] This invention belongs to the field of high-frequency transformers, and specifically relates to an air-core high-frequency transformer and its modeling method. Background Technology

[0002] Compared to traditional AC power frequency transformers, high-frequency transformers are more widely used in power electronic transformers and DC transformers due to their high operating frequency and small size. However, traditional high-frequency transformers integrate heavy magnetic cores. As the frequency increases, the magnetic core becomes larger and heavier to achieve reliable insulation, resulting in low power density.

[0003] Furthermore, coreless transformers are currently generally described using a mutual inductance circuit model. While this model can simply and effectively characterize the electromagnetic mechanism, it presents difficulties for voltage and current stress analysis, as well as parameter design analysis of passive devices connected to the transformer. Summary of the Invention

[0004] To address the aforementioned problems in the prior art, namely the high weight and low power density of existing high-frequency transformers, this invention provides an air-core high-frequency transformer. The air-core high-frequency transformer has an air-core ring structure, and from the inner ring to the outer ring, the high-frequency transformer includes a first secondary winding, a first primary winding, a second primary winding, and a second secondary winding.

[0005] The first primary winding and the second primary winding are connected in series. The first primary winding is wound with N turns of coil in a single layer clockwise from top to bottom between the input terminal A and the output terminal A1. The second primary winding is wound with N turns of coil in a single layer clockwise from top to bottom between the input terminal X and the output terminal X1. The value of N is in the range of [10 50].

[0006] The first secondary winding and the second secondary winding are connected in series. The first secondary winding has an M-turn coil wound in a single layer clockwise from top to bottom between the input end a and the output end a1. The second secondary winding has an M-turn coil wound in a single layer clockwise from top to bottom between the input end x and the output end x1. The value of M is in the range of [10 50].

[0007] In some preferred embodiments, an insulating layer 1 is provided between the first secondary winding and the first primary winding.

[0008] In some preferred embodiments, the insulating layer 1 is a solid epoxy resin material, and the thickness of the insulating layer 1 ranges from 1 mm to 10 mm.

[0009] In some preferred embodiments, an insulating layer 2 is provided between the second primary winding and the second secondary winding.

[0010] In some preferred embodiments, the insulating layer 2 is a solid epoxy resin material, and the thickness of the insulating layer 2 ranges from 1 mm to 10 mm.

[0011] In some preferred embodiments, both the first primary winding and the second primary winding are Litz wires, and the winding thickness ranges from 1mm to 10mm.

[0012] In some preferred embodiments, the inner diameter of the first secondary winding is in the range of [10mm 100mm].

[0013] In some preferred embodiments, the inner diameter of the second primary winding is in the range of [60mm 500mm].

[0014] In another aspect, the present invention proposes a modeling method for an air-core high-frequency transformer. Based on the aforementioned air-core high-frequency transformer, the modeling method includes:

[0015] Let the primary-side equivalent resistance be R. P Let the original equivalent leakage inductance be L. P The primary-side equivalent resistance R P The measurement was obtained by measuring the AX terminal of the first primary winding and the second primary winding connected in series.

[0016] Let the primary-side equivalent resistance be R. S Let L be the equivalent leakage inductance of the secondary side. s The primary-side equivalent resistance R S The measurement is obtained by connecting the first secondary winding and the second secondary winding in series at the ax end;

[0017] Let the equivalent magnetizing inductance be L. m Based on the number of turns N in the primary winding and the number of turns M in the secondary winding of the air-core high-frequency transformer, the equivalent magnetizing inductance of the air-core high-frequency transformer is constructed as L. m The model and the equivalent leakage inductance of the primary edge are L. P The equivalent leakage inductance of the model and secondary side is L. s Model.

[0018] In some preferred embodiments, the equivalent magnetizing inductance is L m The model and the equivalent leakage inductance of the primary edge are L. P The equivalent leakage inductance of the model and secondary side is L. s The models are represented as follows:

[0019] L m =k TF M mutual

[0020] L P =L1-L m

[0021]

[0022] Among them, A TF =N / M is the voltage turns ratio of the equivalent ideal voltage transformer of the air-core high-frequency transformer, M mutual L1 is the measured mutual inductance between the first primary winding and the second primary winding connected in series, and between the first secondary winding and the second secondary winding connected in series. L2 is the measured inductance between the first primary winding and the second primary winding.

[0023] The beneficial effects of this invention are:

[0024] (1) The air-core high-frequency transformer of the present invention has the advantages of light weight and small size compared with the traditional high-frequency transformer with magnetic core. Furthermore, the current directions in the first primary winding and the second primary winding are opposite, and the current directions in the first secondary winding and the second secondary winding are opposite. The main magnetic flux of the primary and secondary windings is constrained inside the high-frequency transformer, thereby greatly improving the coupling ability and effectively improving the power density of the transformer.

[0025] (2) The air-core high-frequency transformer of the present invention establishes a T-type equivalent circuit of the air-core high-frequency transformer, which can draw on the traditional transformer analysis method, simplify the analysis and design process of peripheral matching circuit components, thereby improving design efficiency. Attached Figure Description

[0026] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0027] Figure 1 This is a schematic diagram of the structure of the air-core high-frequency transformer of the present invention;

[0028] Figure 2 This is a top view of the air-core high-frequency transformer of the present invention;

[0029] Figure 3 This is a cross-sectional view of the air-core high-frequency transformer of the present invention;

[0030] Figure 4 This is a schematic diagram showing the connection between the first primary winding and the second primary winding of the air-core high-frequency transformer of the present invention.

[0031] Figure 5 This is a schematic diagram showing the connection between the first secondary winding and the second secondary winding of the air-core high-frequency transformer of the present invention;

[0032] Figure 6 This is a schematic diagram of the equivalent circuit model of the air-core high-frequency transformer of the present invention. Detailed Implementation

[0033] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0034] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0035] This invention provides an air-core high-frequency transformer that overcomes the shortcomings of existing technologies. The primary and secondary windings are tightly coupled, and the inner and outer current directions are opposite, confining the main magnetic flux within the transformer. Furthermore, through analysis, an equivalent model of the air-core high-frequency transformer with a conventional T-type equivalent circuit is established, which improves parameter design efficiency and reduces design difficulty.

[0036] The present invention provides an air-core high-frequency transformer, wherein the air-core high-frequency transformer has an air-core ring structure, and the high-frequency transformer includes a first secondary winding, a first primary winding, a second primary winding, and a second secondary winding from the inner ring to the outer ring.

[0037] The first primary winding and the second primary winding are connected in series. The first primary winding is wound with N turns of coil in a single layer clockwise from top to bottom between the input terminal A and the output terminal A1. The second primary winding is wound with N turns of coil in a single layer clockwise from top to bottom between the input terminal X and the output terminal X1. The value of N is in the range of [10 50].

[0038] The first secondary winding and the second secondary winding are connected in series. The first secondary winding has an M-turn coil wound in a single layer clockwise from top to bottom between the input end a and the output end a1. The second secondary winding has an M-turn coil wound in a single layer clockwise from top to bottom between the input end x and the output end x1. The value of M is in the range of [10 50].

[0039] To more clearly explain the air-core high-frequency transformer of the present invention, the following description is in conjunction with... Figure 1 The modules in the embodiments of the present invention will be described in detail below.

[0040] like Figure 2 and Figure 3 The figures shown are a top view and a cross-sectional view of the air-core high-frequency transformer of the present invention. The air-core high-frequency transformer of the first embodiment of the present invention has an air-core ring structure, which includes a first secondary winding, a first primary winding, a second primary winding, and a second secondary winding from the inner ring to the outer ring. Each module is described in detail below:

[0041] The first primary winding and the second primary winding are connected in series, the first secondary winding and the second secondary winding are connected in series, an insulation layer 1 is provided between the first secondary winding and the first primary winding, and an insulation layer 2 is provided between the second primary winding and the second secondary winding.

[0042] like Figure 4 The diagram shows the connection between the first primary winding and the second primary winding of the air-core high-frequency transformer of the present invention. The first primary winding, after entering from the input terminal A, is wound with N turns of coil clockwise along the outer side of the insulation layer 1 from top to bottom, and connected to the output terminal A1. The value of N ranges from [10 50]. The second primary winding, after entering from the input terminal X, is wound with N turns of coil clockwise along the inner side of the insulation layer 2 from top to bottom, and connected to the output terminal X1. The value of N ranges from [10 50]. The output terminal A1 of the first primary winding is connected to the output terminal X1 of the second primary winding.

[0043] like Figure 5 The diagram shows the connection between the first and second secondary windings of the air-core high-frequency transformer of the present invention. The first secondary winding, after entering from the input terminal a, is wound with M turns of coil clockwise along the inner side of the insulation layer 1 from top to bottom, and connected to the output terminal a1. The value of M ranges from [10 50]. The second secondary winding, after entering from the input terminal x, is wound with M turns of coil clockwise along the outer side of the insulation layer 2 from top to bottom, and connected to the output terminal x1. The value of M ranges from [10 50]. The output terminal a1 of the first secondary winding is connected to the output terminal x1 of the second secondary winding.

[0044] The air-core high-frequency transformer operates between 10kHz and 100kHz. The inner diameter d1 (i.e., the inner diameter of the first secondary winding) ranges from [10mm to 100mm], and the inner diameter d2 (i.e., the inner diameter of the second primary winding) ranges from [60mm to 500mm].

[0045] The first and second primary windings of the air-core high-frequency transformer both use Litz wire, and the winding thickness ranges from 1mm to 10mm.

[0046] The first and second secondary windings of the air-core high-frequency transformer both use Litz wire, and the winding thickness ranges from 1mm to 10mm.

[0047] The epoxy insulation layer 1 and insulation layer 2 of the air-core high-frequency transformer are both made of solid epoxy resin material with a thickness range of [1mm 10mm].

[0048] The value range of the height h of the air-core high-frequency transformer is [100mm 500mm].

[0049] The modeling method for an air-core high-frequency transformer according to the second embodiment of the present invention, based on the above-mentioned air-core high-frequency transformer, includes:

[0050] Let the primary-side equivalent resistance be R. P Let the original equivalent leakage inductance be L. P The primary-side equivalent resistance R P The measurement was obtained by measuring the AX terminal of the first primary winding and the second primary winding connected in series.

[0051] Let the primary-side equivalent resistance be R. S Let L be the equivalent leakage inductance of the secondary side. s The primary-side equivalent resistance R S The measurement is obtained by connecting the first secondary winding and the second secondary winding in series at the ax end;

[0052] Let the equivalent magnetizing inductance be L. m Based on the number of turns N in the primary winding and the number of turns M in the secondary winding of the air-core high-frequency transformer, the equivalent magnetizing inductance of the air-core high-frequency transformer is constructed as L. m The model and the equivalent leakage inductance of the primary edge are L. P The model and the equivalent leakage inductance of the secondary side are represented by the Ls model.

[0053] like Figure 6 The diagram shown is a schematic representation of the equivalent circuit model of the air-core high-frequency transformer of this invention. The model includes the primary-side equivalent resistance R. P Original equivalent leakage inductance L P Equivalent magnetizing inductance L m Equivalent ideal transformer, secondary equivalent resistance R S Secondary side equivalent leakage inductance L s In the equivalent circuit model, the input terminal A of the first primary winding is connected to the equivalent resistance R. P and equivalent leakage inductance L P Then, it is connected to the equivalent magnetizing inductance L. m Terminal P L The input terminal X of the second primary winding is directly connected to the equivalent magnetizing inductance L. m Terminal N L Equivalent magnetizing inductance L m It is connected in parallel with an equivalent ideal transformer, wherein the equivalent magnetizing inductance L m Terminal P L Connected to the primary terminal P1 of the equivalent ideal transformer, the equivalent magnetizing inductance L m Terminal N L Connect to the primary terminal P2 of the equivalent ideal transformer. Connect the equivalent resistance R to the secondary terminal S1 of the equivalent ideal transformer. S and equivalent leakage inductance L s Then, it is connected to the first secondary winding input terminal a. The equivalent ideal transformer's corresponding secondary winding terminal S2 is directly connected to the second secondary winding input terminal x.

[0054] The equivalent magnetizing inductance is L m The model and the equivalent leakage inductance of the primary edge are L. P The equivalent leakage inductance of the model and secondary side is L. s The models are represented as shown in equations (1) to (3):

[0055] L m =A TF M mutual (1)

[0056] L P =L1-L m (2)

[0057]

[0058] Where, k TF =N / M is the voltage turns ratio of the equivalent ideal voltage transformer of the air-core high-frequency transformer, M mutual L1 is the measured mutual inductance between the first primary winding and the second primary winding connected in series, and between the first secondary winding and the second secondary winding connected in series. L2 is the measured inductance between the first primary winding and the second primary winding.

[0059] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process and related explanations of the methods described above can be found in the corresponding processes in the foregoing system embodiments, and will not be repeated here.

[0060] It should be noted that the air-core high-frequency transformer and method provided in the above embodiments are only illustrative examples of the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the modules or steps in the embodiments of the present invention can be further decomposed or combined. For example, the modules in the above embodiments can be merged into one module, or further divided into multiple sub-modules to complete all or part of the functions described above. The names of the modules and steps involved in the embodiments of the present invention are only for distinguishing the various modules or steps and are not considered as an improper limitation of the present invention.

[0061] A device according to a third embodiment of the present invention includes:

[0062] At least one processor; and

[0063] A memory communicatively connected to at least one of the processors; wherein,

[0064] The memory stores instructions that can be executed by the processor to implement the above-described modeling method for air-core high-frequency transformers.

[0065] A computer-readable storage medium according to a fourth embodiment of the present invention stores computer instructions, which are executed by the computer to implement the above-described modeling method for air-core high-frequency transformers.

[0066] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process and related descriptions of the storage device and processing device described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0067] Those skilled in the art will recognize that the modules and method steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. The programs corresponding to the software modules and method steps can be placed in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disks, removable disks, CD-ROMs, or any other form of storage medium known in the art. To clearly illustrate the interchangeability of electronic hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in electronic hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the invention.

[0068] The terms “first”, “second”, etc., are used to distinguish similar objects, not to describe or indicate a specific order or sequence.

[0069] The term "comprising" or any other similar term is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus / device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent in such process, method, article, or apparatus / device.

[0070] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A hollow-core high-frequency transformer, wherein the hollow-core high-frequency transformer has a hollow-core ring structure, characterized in that, The high-frequency transformer includes a first secondary winding, a first primary winding, a second primary winding, and a second secondary winding from the inner ring to the outer ring. The first primary winding and the second primary winding are connected in series. The first primary winding is wound with N turns of coil in a single layer clockwise from top to bottom between the input terminal A and the output terminal A1. The second primary winding is wound with N turns of coil in a single layer clockwise from top to bottom between the input terminal X and the output terminal X1. The value of N is in the range of [10 50]. The first secondary winding and the second secondary winding are connected in series. The first secondary winding has an M-turn coil wound in a single layer clockwise from top to bottom between the input end a and the output end a1. The second secondary winding has an M-turn coil wound in a single layer clockwise from top to bottom between the input end x and the output end x1. The value of M is in the range of [10 50].

2. The air-core high-frequency transformer according to claim 1, characterized in that, An insulating layer 1 is provided between the first secondary winding and the first primary winding.

3. The air-core high-frequency transformer according to claim 2, characterized in that, The insulating layer 1 is a solid epoxy resin material, and the thickness of the insulating layer 1 ranges from 1 mm to 10 mm.

4. The air-core high-frequency transformer according to claim 1, characterized in that, An insulating layer 2 is provided between the second primary winding and the second secondary winding.

5. The air-core high-frequency transformer according to claim 4, characterized in that, The insulating layer 2 is a solid epoxy resin material, and the thickness of the insulating layer 2 ranges from 1 mm to 10 mm.

6. The air-core high-frequency transformer according to claim 1, characterized in that, Both the first primary winding and the second primary winding are Litz wires, and the winding thickness ranges from 1 mm to 10 mm.

7. The air-core high-frequency transformer according to claim 1, characterized in that, The inner diameter of the first secondary winding is in the range of [10mm 100mm].

8. The air-core high-frequency transformer according to claim 1, characterized in that, The inner diameter of the second primary winding is in the range of [60mm 500mm].

9. A modeling method for an air-core high-frequency transformer, characterized in that, Based on the air-core high-frequency transformer according to any one of claims 1-8, the modeling method includes: Let the primary-side equivalent resistance be R. P Let the original equivalent leakage inductance be L. P The primary-side equivalent resistance R P The measurement was obtained by measuring the AX terminal of the first primary winding and the second primary winding connected in series. Let the primary-side equivalent resistance be R. S Let L be the equivalent leakage inductance of the secondary side. s The primary-side equivalent resistance R S The measurement is obtained by connecting the first secondary winding and the second secondary winding in series at the ax end; Let the equivalent magnetizing inductance be L. m Based on the number of turns N in the primary winding and the number of turns M in the secondary winding of the air-core high-frequency transformer, the equivalent magnetizing inductance of the air-core high-frequency transformer is constructed as L. m The model and the equivalent leakage inductance of the primary edge are L. P The equivalent leakage inductance of the model and secondary side is L. s Model.

10. The modeling method for air-core high-frequency transformers according to claim 9, characterized in that, The equivalent excitation inductance is L m The model and the equivalent leakage inductance of the primary edge are L. P The equivalent leakage inductance of the model and secondary side is L. s The models are represented as follows: L m =k TF M mutual L p =L1-L m Where, k TF =N / M is the voltage turns ratio of the equivalent ideal voltage transformer of the air-core high-frequency transformer, M mutual L1 is the measured mutual inductance between the first primary winding and the second primary winding connected in series, and between the first secondary winding and the second secondary winding connected in series. L2 is the measured inductance between the first primary winding and the second primary winding.

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