CN117577425A - Sigma converter transformer and inductance integrated structure capable of reducing magnetic core volume - Google Patents

Sigma converter transformer and inductance integrated structure capable of reducing magnetic core volume Download PDF

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Publication number
CN117577425A
CN117577425A CN202311609560.2A CN202311609560A CN117577425A CN 117577425 A CN117577425 A CN 117577425A CN 202311609560 A CN202311609560 A CN 202311609560A CN 117577425 A CN117577425 A CN 117577425A
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CN
China
Prior art keywords
transformer
magnetic core
inductor
magnetic
integrated structure
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Pending
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CN202311609560.2A
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Chinese (zh)
Inventor
吴伊楠
伍群芳
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Wuxi Weiwan Intelligent Technology Co ltd
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Wuxi Weiwan Intelligent Technology Co ltd
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Priority to CN202311609560.2A priority Critical patent/CN117577425A/en
Publication of CN117577425A publication Critical patent/CN117577425A/en
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/24—Magnetic cores
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/28—Coils; Windings; Conductive connections
    • H01F27/30—Fastening or clamping coils, windings, or parts thereof together; Fastening or mounting coils or windings on core, casing, or other support
    • H01F27/306—Fastening or mounting coils or windings on core, casing or other support
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/34—Special means for preventing or reducing unwanted electric or magnetic effects, e.g. no-load losses, reactive currents, harmonics, oscillations, leakage fields
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F3/00—Cores, Yokes, or armatures
    • H01F3/10—Composite arrangements of magnetic circuits
    • H01F3/14—Constrictions; Gaps, e.g. air-gaps
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Composite Materials (AREA)
  • Manufacturing & Machinery (AREA)
  • Coils Or Transformers For Communication (AREA)

Abstract

The invention relates to the technical field of integration of a sigma converter transformer and an inductor, and discloses a sigma converter transformer and an inductor integrated structure for reducing the volume of a magnetic core, wherein the integrated structure is composed of an inductor winding and a transformer winding, and the construction of the integrated structure comprises the following steps: roughing the magnetic core by adopting an AP method, wherein the AP method for roughing the magnetic core of the transformer uses an empirical formula, whereinP o For output power (in W), deltaABIs magnetic fluxThe density variation (unit T), fs is the transformer operating frequency (unit Hz), the coefficient k=0.017, empirical value. According to the sigma converter transformer and inductor integrated structure with the reduced magnetic core volume, the independent Buck circuit inductor in the sigma converter is integrated with the DCX transformer, the side posts of the magnetic core are reduced, the magnetic core volume is reduced, in addition, the magnetic fields of the transformer and the inductor cancel each other, the magnetic flux density in the magnetic core is reduced, and the loss is reduced.

Description

Sigma converter transformer and inductance integrated structure capable of reducing magnetic core volume
Technical Field
The invention relates to the technical field of integration of a sigma converter transformer and an inductor, in particular to a sigma converter transformer and an inductor integrated structure capable of reducing the volume of a magnetic core.
Background
LLC resonant converters are widely used in various industrial fields (cluster servers, digital product adapters, etc.). When LLC open-loop works at the resonance point, the efficiency is highest, and a Buck circuit is additionally adopted for voltage regulation, namely a sigma converter. In order to reduce the height of the magnetic core and save the cost, an integrated structure of a transformer and an inductor is adopted to reduce the number of magnetic pieces and improve LLC power density. In the existing mode, when the litz wire winding is used, the LLC transformer and the Buck filter inductor are wound on corresponding magnetic cores respectively, and the magnetic cores are mutually independent. Because the transformer and the inductance core are mutually independent, the traditional scheme occupies a large volume and has high weight, so that the whole transformer is heavy, the power density is low, and the core loss is large. At present, no structure for integrating a Buck circuit inductor and an LLC transformer of a sigma converter exists.
The transformer and the inductor adopt an AP method to respectively roughen the effective sectional area of the magnetic core, and then the primary side turns of the transformer are obtained according to Faraday electromagnetic induction theorem:
wherein the method comprises the steps ofU o For the output voltage of the transformer,f s for the operating frequency of the transformer,B m for a pre-selected maximum operating magnetic density,A e is the effective cross-section area of the magnetic core, the transformation ratio isn. The number of turns of the inductor is determined by the formula in whichL b In order to filter the magnitude of the inductance,I Lb_max for the purpose of filtering the inductance maximum value,B Lb_max the maximum magnetic flux density of the inductor is,A eLb is the magnetic core cross-sectional area.
Determining air gap between transformer and Buck inductance needed pad according to inductance value
For inductance, in the above formulaNThe number of turns is taken out,Ltaking an inductance value; in the case of a transformer,Nthe number of turns of the primary side is taken,Land (3) taking the size of the excitation inductor, and finally, finishing the design of the transformer and the design of the filter inductor through window area verification.
The main disadvantage of the first prior art is that the design of the magnetic core of the transformer and the magnetic core of the inductor are performed respectively in the design process, and the number of turns of the transformer is higher or the current peak value of the filter inductor is larger, so that the volume of the magnetic core of the transformer and the magnetic core of the filter inductor is larger, the whole transformer is heavy, and the power density is low; therefore, there is a strong need for a sigma-transformer and inductor integrated structure with reduced magnetic core volume to solve the above-mentioned problems.
Disclosure of Invention
The invention aims to provide a sigma converter transformer and inductance integrated structure with reduced magnetic core volume, which is composed of an inductance winding and a transformer winding, and the construction of the integrated structure comprises the following steps:
s1, roughing a magnetic core by adopting an AP method, wherein the AP method for roughing the magnetic core of the transformer uses an empirical formula, wherein the AP method comprises the following steps ofP o For output power (in W), deltaABAs the amount of change in magnetic flux density (unit T),f s for the operating frequency of the transformer (in Hz), the coefficient k=0.017, empirical value;
s2, an AP method experimental formula is used for primary selection of the inductance core, whereinLIs the inductance (unit H),I sp for maximum peak short-circuit current (unit a),B max maximum magnetic flux density (unit T), deltaIDelta as the current variation (unit A)B max Is the maximum magnetic flux density swing (unit T),I 1L is the effective value of the full load current (unit A), coefficient K 1 =0.027, empirical value;
s3, selecting a transformer for roughing magnetic cores by S1S2, and selecting magnetic cores according to roughingA e Selecting the size of the sectional area of a side column of a winding of the integrated magnetic core;
s4, selecting the size of the magnetic core according to the S3, and adopting a formula
To determine the size of the air gap between the inductor and the transformer, whereinA e For the chosen size of the leg cross-sectional area of the core, for the inductance,Nin order to have a number of turns,Lis the filter inductance value; in the case of a transformer,Nfor the number of turns of the primary side,Lis the excitation inductance value.
Preferably, the transformer winding adopts litz wire, 8 turns are wound clockwise on a right side column to form a primary side, 4 turns are wound coaxially and a center tap is led out, and the direction is determined according to the same name end of the transformer to form a secondary side of the transformer.
Preferably, an air gap is formed on the left column of the selected magnetic core, and the air gap is equal to the air gap corresponding to the size of the filter inductor.
Preferably, an air gap is formed on the right column of the selected magnetic core, and the air gap is equal to the corresponding air gap of the exciting inductance of the transformer.
Preferably, the central leg of the core is free of an air gap as a common magnetic path.
Preferably, the inductor winding is litz wire and is wound on the left column in a counterclockwise direction for 16 turns.
Preferably, the winding direction used has: the magnetic flux direction of the transformer winding and the magnetic flux direction generated by the inductance winding are along opposite directions on the central magnetic column of the public magnetic circuit.
Compared with the prior art, the invention has the following beneficial effects:
1. this reduce sigma converter transformer and inductance integrated configuration of magnetic core volume integrates independent Buck circuit inductance and DCX transformer in the sigma converter, has reduced the side column of magnetic core, has reduced the volume of magnetic core, and in addition, the magnetic field of transformer and inductance offset each other, and the magnetic flux density in the magnetic core reduces, and the loss reduces.
2. The sigma converter transformer and inductance integrated structure capable of reducing the volume of the magnetic core reduces the volume of the magnetic core by 33.1%, and meanwhile simulation verifies that the magnetic flux of the magnetic core is not greatly affected;
3. the invention provides a sigma converter transformer and inductance integrated structure for reducing the volume of a magnetic core, which has expansibility, can be used in transformers and inductance integrated structures with other topologies, and has a certain significance for increasing the power density of the converter.
Drawings
Other features, objects and advantages of the present application will become more apparent upon reading of the detailed description of non-limiting embodiments, made with reference to the following drawings, in which:
FIG. 1 is a schematic diagram of an integrated winding structure according to the present invention;
fig. 2 is a schematic diagram illustrating winding directions of a transformer winding and an inductance winding according to the present invention;
FIG. 3 is a magnetic core flux flow pattern diagram of an integrated magnetic core structure according to the present invention;
FIG. 4 is a diagram of a magnetoresistive pattern of an integrated core structure according to the present invention.
Description of the embodiments
The present application is described in further detail below with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for convenience of description, only the part related to the invention is shown in the accompanying drawings, and in the embodiments of the invention: the different kinds of cross-sectional lines in the drawings are not marked according to national standards, and the material of the elements is not required, so that the cross-sectional views of the elements in the drawings are distinguished.
Referring to fig. 1-4, a sigma-transformer and inductor integrated structure for reducing the volume of a magnetic core, the integrated structure comprising an inductor winding and a transformer winding, the integrated structure comprising the steps of:
s1, roughing a magnetic core by adopting an AP method, wherein the AP method for roughing the magnetic core of the transformer uses an empirical formula, wherein the AP method comprises the following steps ofP o For output power (in W), deltaABAs the amount of change in magnetic flux density (unit T),f s for the operating frequency of the transformer (in Hz), the coefficient k=0.017, empirical value;
s2, an AP method experimental formula is used for primary selection of the inductance core, whereinLIs the inductance (unit H),I sp for maximum peak short-circuit current (unit a),B max maximum magnetic flux density (unit T), deltaIDelta as the current variation (unit A)B max Is the maximum magnetic flux density swing (unit T),I 1L is the effective value of the full load current (unit A), coefficient K 1 =0.027, empirical value;
s3, selecting a transformer for roughing magnetic cores by S1S2, and selecting magnetic cores according to roughingA e Selecting the size of the sectional area of a side column of a winding of the integrated magnetic core;
s4, selecting the size of the magnetic core according to the S3, and adopting a formula
To determine the size of the air gap between the inductor and the transformer, whereinA e To be selected asThe size of the cross-sectional area of the leg of the core, for inductance,Nin order to have a number of turns,Lis the filter inductance value; in the case of a transformer,Nfor the number of turns of the primary side,Lis the excitation inductance value.
The transformer winding adopts litz wire, 8 turns are wound clockwise on a right side column to form a primary side, 4 turns are wound coaxially and a center tap is led out, and the direction is determined according to the same name end of the transformer and is a secondary side of the transformer.
And an air gap is formed on the left column of the selected magnetic core, and the air gap is equal to the air gap corresponding to the size of the filter inductor.
And an air gap is formed on the right column of the selected magnetic core, and the air gap is equal to the corresponding air gap of the exciting inductance of the transformer.
Wherein, the central magnetic column of the magnetic core is not opened with an air gap and is used as a public magnetic circuit.
The inductance winding adopts litz wire, and 16 turns are wound anticlockwise on the left column.
The winding direction adopted is as follows: the magnetic flux direction of the transformer winding and the magnetic flux direction generated by the inductance winding are along opposite directions on the central magnetic column of the public magnetic circuit.
In the conventional structure, the transformer core and the inductor core generate magnetic fluxes of 0.5 Φ1 and 0.5 Φ2 at the side posts, the main magnetic fluxes generated at the central magnetic post are Φ1 and Φ2 respectively, and the magnetic fluxes at the side posts of the core generate more core loss. The magnetic flux distribution in the structure that this patent put forward is as shown in fig. 4, has reduced the side post and has kept the main magnetic circuit magnetic flux of transformer and inductance to be phi 1 and phi 2 unchangeable respectively with traditional structure, has avoided the iron core loss on the side post and has effectively reduced the magnetic element volume under the circumstances that does not influence inductance and transformer work, and the magnetic flux is inductance and transformer winding magnetic flux subtraction value |phi 1-phi 2|onthe public magnetic circuit simultaneously, has avoided the magnetic density too high on the public magnetic circuit.
To verify the effectiveness of the present invention, experimental verification was performed using the set of transformer parameters and inductance parameters of table I as an example.
Under the current transformer parameters, an ANSYS is utilized to simulate an integrated structure, and the simulation results of the traditional structure and the structure provided by the patent show that the size of a magnetic core is reduced by 33.1%, and compared with the magnetic core before integration, the magnetic flux in the magnetic core is not greatly influenced;
the sigma-transformer and inductor integrated structure has a reduced magnetic core volume. The independent Buck circuit inductor in the sigma converter is integrated with the DCX transformer, so that side posts of the magnetic core are reduced, and the size of the magnetic core is reduced. In addition, the magnetic fields of the transformer and the inductor cancel each other, the magnetic flux density in the magnetic core is reduced, and the loss is reduced; the magnetic core volume is reduced by 33.1%, meanwhile, simulation verifies that the magnetic flux of the magnetic core is not greatly influenced, and the structure has expansibility, can be used in integrated structures of transformers and inductors of other topologies, and has a certain significance for increasing the power density of the converter.
What is not described in detail in this specification is prior art known to those skilled in the art.
The foregoing description is only of the preferred embodiments of the present application and is presented as a description of the principles of the technology being utilized. It will be appreciated by persons skilled in the art that the scope of the invention referred to in this application is not limited to the specific combinations of features described above, but also covers other technical solutions which may be formed by any combination of the features described above or their equivalents without departing from the inventive concept. Such as the above-described features and technical features having similar functions (but not limited to) disclosed in the present application are replaced with each other.

Claims (7)

1. A sigma converter transformer and inductor integrated structure for reducing the volume of a magnetic core, the integrated structure comprising an inductor winding and a transformer winding, characterized in that: the construction of the integrated structure comprises the following steps:
s1, roughing a magnetic core by adopting an AP method, wherein the AP method for roughing the magnetic core of the transformer uses an empirical formula, wherein the AP method comprises the following steps ofP o For output power (in W), deltaABAs the amount of change in magnetic flux density (unit T),f s for the operating frequency of the transformer (in Hz), the coefficient k=0.017, empirical value;
；
s2, an AP method experimental formula is used for primary selection of the inductance core, whereinLIs the inductance (unit H),I sp for maximum peak short-circuit current (unit a),B max maximum magnetic flux density (unit T), deltaIDelta as the current variation (unit A)B max Is the maximum magnetic flux density swing (unit T),I 1L is the effective value of the full load current (unit A), coefficient K 1 =0.027, empirical value;
；
s3, selecting a transformer for roughing magnetic cores by S1S2, and selecting magnetic cores according to roughingA e Selecting the size of the sectional area of a side column of a winding of the integrated magnetic core;
s4, selecting the size of the magnetic core according to the S3, and adopting a formula
；
To determine the size of the air gap between the inductor and the transformer, whereinA e For the chosen size of the leg cross-sectional area of the core, for the inductance,Nin order to have a number of turns,Lis the filter inductance value; in the case of a transformer,Nfor the number of turns of the primary side,Lis the excitation inductance value.
2. A sigma-transformer and inductor integrated structure with reduced magnetic core volume as claimed in claim 1, wherein: the transformer winding adopts litz wire, and clockwise winding 8 turns on the right side column is primary side, and coaxial winding 4 turns again and draw out the center tap, and the direction is confirmed according to the transformer homonymous end, is the transformer secondary side.
3. A sigma-transformer and inductor integrated structure with reduced magnetic core volume as claimed in claim 1, wherein: and an air gap is formed on the left column of the selected magnetic core, and the air gap is equal to the air gap corresponding to the size of the filter inductor.
4. A sigma-transformer and inductor integrated structure with reduced magnetic core volume as claimed in claim 1, wherein: and an air gap is formed on the right column of the selected magnetic core, and the air gap is equal to the corresponding air gap of the exciting inductance of the transformer.
5. A sigma-transformer and inductor integrated structure with reduced magnetic core volume as claimed in claim 1, wherein: the central pole of the magnetic core is not opened with an air gap and is used as a public magnetic circuit.
6. A sigma-transformer and inductor integrated structure with reduced magnetic core volume as claimed in claim 1, wherein: the inductor winding adopts litz wire, and is anticlockwise wound 16 turns on the left column.
7. A sigma-transformer and inductor integrated structure with reduced magnetic core volume as claimed in claim 1, wherein: the winding direction adopted is as follows: the magnetic flux direction of the transformer winding and the magnetic flux direction generated by the inductance winding are along opposite directions on the central magnetic column of the public magnetic circuit.
CN202311609560.2A 2023-11-29 2023-11-29 Sigma converter transformer and inductance integrated structure capable of reducing magnetic core volume Pending CN117577425A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202311609560.2A CN117577425A (en) 2023-11-29 2023-11-29 Sigma converter transformer and inductance integrated structure capable of reducing magnetic core volume

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202311609560.2A CN117577425A (en) 2023-11-29 2023-11-29 Sigma converter transformer and inductance integrated structure capable of reducing magnetic core volume

Publications (1)

Publication Number Publication Date
CN117577425A true CN117577425A (en) 2024-02-20

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Family Applications (1)

Application Number Title Priority Date Filing Date
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Country Status (1)

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