阅读说明：本技术 一种集成漏感和激磁感的变压器磁集成结构及其集成方法 (Transformer magnetic integration structure integrating leakage inductance and excitation inductance and integration method thereof ) 是由 许国 申秋霞 陈孝莺 孙尧 粟梅 王辉 刘永露 宁光富 于 2020-12-21 设计创作，主要内容包括：本发明公开的一种集成漏感和激磁感的变压器磁集成结构及其集成方法,属于电力电子领域的高频隔离开关电源方向。为克服上述常用的磁集成方法中磁芯结构非标准或者磁芯体积利用率低、设计复杂、具有推广应用方面的局限性等相关问题,本发明针对常用类型的含有漏感、激磁感和变压器三种磁性元件结构的变换器,使用两个标准的UI磁芯,通过合理设计绕组连接方式和参数,实现漏感、激磁感和变压器之间的集成,与分立的磁性元件相比,能够减少变换器的磁性元件数目,缩小在变换器中所占的体积比例,进一步缩小变换器系统的体积,提高功率密度这一重要指标,实现系统高效、高功率密度运行,提高运行的灵活性和可靠性。(The invention discloses a transformer magnetic integration structure integrating leakage inductance and excitation inductance and an integration method thereof, belonging to the high-frequency isolation switch power supply direction in the field of power electronics. In order to overcome the problems of nonstandard magnetic core structure or low magnetic core volume utilization rate, complex design, limitation in popularization and application and the like in the common magnetic integration method, the invention uses two standard UI magnetic cores aiming at the converter with three magnetic element structures of leakage inductance, excitation inductance and a transformer, realizes the integration among the leakage inductance, the excitation inductance and the transformer by reasonably designing the winding connection mode and parameters.)

1. The utility model provides an integrated transformer magnetism integrated configuration who leaks inductance and excitation inductance which characterized in that: primary winding N comprising UI core A, UI core B, UI core A_p1Secondary winding N of UI magnetic core A_s1Primary winding N of UI magnetic core B_p2Secondary winding N of UI magnetic core B_s2(ii) a Primary winding N of UI magnetic core A_p1And primary winding N of UI magnetic core B_p2After being connected in series, the port 1 and the port 2 are formed, the port 1 and the port 2 are connected with a primary side voltage input end, and a secondary winding N of a UI magnetic core A_s1And secondary winding N of UI core B_s2The port 3 and the port 4 are connected in series to form a port, and the port 3 and the port 4 are connected with a secondary side voltage output end and communicated withAnd through the connection mode of the magnetic core structure and the winding, the magnetic integration of the transformer with leakage inductance and excitation inductance is realized.

2. The magnetic integrated structure of the transformer integrating the leakage inductance and the excitation inductance as claimed in claim 1, wherein: the magnetic integrated structure meets kirchhoff voltage law, as shown in formula (1):

wherein v is_p1、v_p2Primary windings N of cores B of UI A, UI_p1And N_p2Voltage across, v_s1、v_s2Secondary windings N of cores B of UI A, UI respectively_s1And N_s2Voltage across, v_pA primary side voltage, v, between port 1 and port 2 formed after the primary side windings are connected in series_sThe secondary side voltage between a port 3 and a port 4 is formed after the secondary side windings are connected in series;

the primary windings and the secondary windings of the two magnetic cores of the magnetic integrated structure are connected in series, and the current flowing in the windings meets the formula (2):

wherein i_p1、i_p2Primary windings N of cores B respectively flowing through UI cores A, UI_p1And N_p2Current of (i)_s1、i_s2Secondary windings N of core B respectively flowing through UI core A, UI_s1And N_s2Current of (i)_p、i_sPrimary side current and secondary side current of the whole body formed by connecting the primary and secondary side windings of the UI magnetic core A and the UI magnetic core B in series are respectively formed;

solving a magnetic flux relation through a transformer reluctance model, wherein the magnetic flux relation is shown as an equation (3):

wherein N is_p1、N_s1Primary winding turn number and secondary winding turn number of UI magnetic core A, N_p2、N_s2Primary winding turns and secondary winding turns of UI magnetic core B respectively, phi₁For the magnetic flux, phi, flowing through the UI core A₂Is the magnetic flux flowing through the UI core B;

substituting the formula (1) and the formula (2) into the formula (3) according to a Faraday's law of electromagnetic induction to obtain the relationship between the primary and secondary side voltages and the primary and secondary side currents of the magnetic integrated transformer structure, as shown in the formula (4):

wherein R is_g1、R_g2Magnetic resistance of core B, UI core A, UI, respectively, since the permeability of UI core is much greater than the permeability of air, μ₀Neglecting UI core reluctance, therefore R_g1、R_g2The reluctance of the air gap opened by the side pole of the magnetic core is considered;

according to the formula (4), the inductance matrix of the equivalent coupling inductance L of the magnetic integrated transformer is shown in the formula (5):

wherein L is₁₁Is self-inductance of primary side, M is mutual inductance, L₂₂Self-induction of the secondary side;

the equivalent relationship between the coupling inductance L and the transformer parameters required by the converter is shown in equation (6), equation (7) and equation (8):

wherein n is the transformation ratio n:1, L of the primary side voltage and the secondary side voltage of the transformer_kFor leakage inductance of transformer, L_mExciting magnetic induction for the transformer;

integrating leakage inductance and excitation inductance of a transformer into the transformer formed by two standard UI magnetic cores through a formula (6), a formula (7) and a formula (8), wherein the magnetic integration structure integrates three magnetic elements comprising the transformer, the leakage inductance of the transformer and the excitation inductance of the transformer; the leakage inductance and the excitation inductance are connected in series, and the two ends of the excitation inductance are connected in parallel, so that the integration of a transformer magnetic integrated structure integrating the leakage inductance and the excitation inductance is realized.

3. The magnetic integrated structure of the transformer integrating the leakage inductance and the excitation inductance as claimed in claim 1 or 2, wherein: UI magnetic core A is standard UI magnetic core A, UI magnetic core B is standard UI magnetic core B.

4. A magnetic integration method of a transformer integrating leakage inductance and excitation inductance, which is used for realizing the integration of the transformer integrating leakage inductance and excitation inductance according to claim 1 or 2, and is characterized in that: comprises the following steps of (a) carrying out,

the method comprises the following steps: determining the transformer parameters, i.e. the transformation ratio n, the leakage inductance L, required to achieve the converter operation_kExcitation inductance L_m；

Step two: obtaining a coupling inductance matrix by equivalent transformer parameters, calculating the actual transformation ratio n' of the transformer according to different requirements as shown in a formula (9)Can be at R_g1＝R_g2Or R_g1≠R_g2Determining the number of winding turns N of two UI cores in both cases_p1、N_s1、N_p2、N_s2；

Step three: after the number of turns is determined, calculating the size of the magnetic resistance according to a formula (5);

step four: in order to prevent the magnetic core from being saturated, the proper cross section area of the magnetic core is determined according to the maximum value of the magnetic flux of the converter;

step five: integrating leakage inductance and excitation inductance of the transformer into a transformer consisting of two standard UI magnetic cores according to the transformer parameters in the step four, and realizing integration of a magnetic integration structure of the transformer integrating the leakage inductance and the excitation inductance; the magnetic integrated structure of the transformer can reduce the number of magnetic elements of the converter, reduce the volume proportion occupied in the converter, further reduce the volume of the converter system, improve the power density, realize the high-efficiency and high-power density operation of the system, and improve the flexibility and the reliability of the operation.

5. The magnetic integration method of the transformer integrating the leakage inductance and the excitation inductance as claimed in claim 4, wherein: the implementation method of the fourth step is that,

step 4.1: the cross-sectional area A of the UI magnetic core A is obtained_e1According to l_g1＝R_g1A_e1μ₀The air gap length l of UI core A can be determined_g1；

Step 4.2: the cross-sectional area A of the UI magnetic core B is obtained_e2According to l_g2＝R_g2A_e2μ₀The air gap length l of UI core B can be determined_g2(ii) a Thus, a two UI core transformer design is completed.

Technical Field

The invention relates to a power electronic magnetic integration technology, in particular to a transformer magnetic integration structure integrating leakage inductance and excitation inductance and an integration method thereof, belonging to the high-frequency isolation switch power supply direction in the power electronic field.

Background

In recent years, due to the rapid development of various converters having characteristics such as high transmission efficiency and easy soft switching, along with the wide application of wide bandgap semiconductor devices such as silicon carbide (SiC) and gallium nitride (GaN), converters are being developed in the direction of high frequency, high efficiency, and high power density. However, these converters usually include a plurality of magnetic elements such as inductors and transformers, and the weight of the magnetic elements accounts for 30% to 40% of the weight of the converter and the volume accounts for 20% to 30% of the total volume of the converter according to statistics, so that the excessive number of the magnetic elements may cause the increase of the weight and the volume of the converter, and limit the improvement of the performance index of the power density.

In order to realize functions such as power transmission, voltage regulation, soft switching and the like, magnetic elements such as inductors and transformers are generally required in the converter, and the number of the magnetic elements is different according to different converter circuits and different realization functions. In 'universal Converter Modulation Control solid Fixed double Cycle Compensation and magnetic Current Design for double Active Bridge DC-DC Converter' published in IEEE Transaction on power electronics journal in 2017, the Converter topology contains three magnetic elements, including leakage inductance, excitation inductance and transformer, the Design of excitation Current is beneficial to the realization of ZVS, but the external parallel excitation inductance further increases the volume of the system and is not beneficial to the improvement of the power density of the Converter. In the article "GaN-based 1-MHz Partial double Active Bridge Converter with Integrated Magnetics" published in IEEE transmission on industrial electronics journal in 2020, an inductor and three transformers are Integrated by using a unique three-side-column magnetic core structure, so that the volume of a magnetic element is greatly reduced, and the current stress of a low-voltage side switching tube is reduced. In 'High-Frequency PCB Winding Transformer With Integrated Inductors for a Bi-Directional inductor Converter' published in IEEE Transmission on power electronics journal in 2019, leakage inductance and excitation inductance are Integrated into an EI magnetic core Transformer, and required magnetic element parameters are obtained through the design of air gaps of an original secondary side Winding, a center pillar and a side pillar, so that the method has important significance for the integration of discrete magnetic elements.

Disclosure of Invention

In order to overcome the problems of nonstandard magnetic core structure or low magnetic core volume utilization rate, complex design, limitation in popularization and application and the like in the common magnetic integration method, the invention discloses a transformer magnetic integration structure integrating leakage inductance and excitation inductance and an integration method thereof, which aim to solve the technical problems that: the converter comprises a transformer, a plurality of standard UI magnetic cores, a plurality of discrete magnetic elements, a plurality of discrete UI magnetic cores, a plurality of discrete UI magnetic elements, a plurality of UI magnetic cores, a plurality of UI magnetic elements, a plurality of UI magnetic cores and a plurality of UI magnetic cores.

The purpose of the invention is realized by the following technical scheme.

The invention discloses a magnetic integration structure of a transformer integrating leakage inductance and excitation inductance, which comprises a primary winding N of a magnetic core B, UI A of a UI magnetic core A, UI_p1Secondary winding N of UI magnetic core A_s1Primary winding N of UI magnetic core B_p2Secondary winding N of UI magnetic core B_s2. Primary winding N of UI magnetic core A_p1And primary winding N of UI magnetic core B_p2After being connected in series, the port 1 and the port 2 are formed, the port 1 and the port 2 are connected with a primary side voltage input end, and a secondary winding N of a UI magnetic core A_s1And secondary winding N of UI core B_s2The port 3 and the port 4 are formed by connecting in series, the port 3 and the port 4 are connected with a secondary side voltage output end, and the magnetic integration of the transformer with leakage inductance and excitation inductance is realized through the magnetic core structure and the winding connection mode.

The magnetic integrated structure meets kirchhoff voltage law, as shown in formula (1):

wherein v is_p1、v_p2Primary windings N of cores B of UI A, UI_p1And N_p2Voltage across, v_s1、v_s2Secondary windings N of cores B of UI A, UI respectively_s1And N_s2Voltage across, v_pA primary side voltage, v, between port 1 and port 2 formed after the primary side windings are connected in series_sThe secondary side voltage between the port 3 and the port 4 is formed after the secondary side windings are connected in series.

The primary windings and the secondary windings of the two magnetic cores of the magnetic integrated structure are connected in series, and the current flowing in the windings meets the formula (2):

wherein i_p1、i_p2Primary windings N of cores B respectively flowing through UI cores A, UI_p1And N_p2Current of (i)_s1、i_s2Secondary windings N of core B respectively flowing through UI core A, UI_s1And N_s2Current of (i)_p、i_sThe primary side current and the secondary side current of the whole body formed by connecting the primary and secondary side windings of the UI magnetic core A and the UI magnetic core B in series are respectively.

Solving a magnetic flux relation through a transformer reluctance model, wherein the magnetic flux relation is shown as an equation (3):

wherein N is_p1、N_s1Primary winding turn number and secondary winding turn number of UI magnetic core A, N_p2、N_s2Primary winding turns and secondary winding turns of UI magnetic core B respectively, phi₁For the magnetic flux, phi, flowing through the UI core A₂Is the magnetic flux that flows through the UI core B.

Substituting the formula (1) and the formula (2) into the formula (3) according to a Faraday's law of electromagnetic induction to obtain the relationship between the primary and secondary side voltages and the primary and secondary side currents of the magnetic integrated transformer structure, as shown in the formula (4):

wherein R is_g1、R_g2Magnetic resistance of core B, UI core A, UI, respectively, since the permeability of UI core is much greater than the permeability of air, μ₀Neglecting UI core reluctance, therefore R_g1、R_g2The reluctance of the air gap opened by the core leg is considered.

According to the formula (4), the inductance matrix of the equivalent coupling inductance L of the magnetic integrated transformer is shown in the formula (5):

wherein L is₁₁Is self-inductance of primary side, M is mutual inductance, L₂₂Is self-induction at the side.

The equivalent relationship between the coupling inductance L and the transformer parameters required by the converter is shown in equation (6), equation (7) and equation (8):

wherein n is the transformation ratio n:1, L of the primary side voltage and the secondary side voltage of the transformer_kFor leakage inductance of transformer, L_mThe magnetic induction is excited for the transformer.

Through a formula (6), a formula (7) and a formula (8), the leakage inductance and the excitation inductance of the transformer are integrated into the transformer formed by two standard UI magnetic cores, and the magnetic integration structure integrates three magnetic elements including the transformer, the leakage inductance of the transformer and the excitation inductance of the transformer. The leakage inductance and the excitation inductance are connected in series, and the two ends of the excitation inductance are connected in parallel, so that the integration of a transformer magnetic integrated structure integrating the leakage inductance and the excitation inductance is realized.

Preferably, the UI magnetic core a is a standard UI magnetic core a, and the UI magnetic core B is a standard UI magnetic core B.

The invention also discloses a transformer magnetism integration method integrating leakage inductance and excitation inductance, which is used for realizing the integration of the transformer magnetism integrating the leakage inductance and the excitation inductance and comprises the following steps:

the method comprises the following steps: determining the transformer parameters, i.e. the transformation ratio n, the leakage inductance L, required to achieve the converter operation_kExcitation inductance L_m；

Step two: obtaining a coupling inductance matrix by equivalent transformer parameters, calculating the actual transformation ratio n 'of the transformer as shown in formula (9), and according to different requirements, calculating the actual transformation ratio n' of the transformer at R_g1＝R_g2Or R_g1≠R_g2Determining the number of winding turns N of two UI cores in both cases_p1、N_s1、N_p2、N_s2；

Step three: after the number of turns is determined, calculating the size of the magnetic resistance according to a formula (5);

step four: to prevent core saturation, the appropriate core cross-sectional area is determined based on the maximum magnetic flux at which the transformer operates.

Step 4.1: the cross-sectional area A of the UI magnetic core A is obtained_e1According to l_g1＝R_g1A_e1μ₀The air gap length l of UI core A can be determined_g1。

Step 4.2: the cross-sectional area A of the UI magnetic core B is obtained_e2According to l_g2＝R_g2A_e2μ₀The air gap length l of UI core B can be determined_g2. Thus, a two UI core transformer design is completed.

Step five: and integrating the leakage inductance and the excitation inductance of the transformer into the transformer formed by the two standard UI magnetic cores according to the transformer parameters in the step four, so as to realize the integration of the magnetic integration structure of the transformer integrating the leakage inductance and the excitation inductance. The magnetic integrated structure of the transformer can reduce the number of magnetic elements of the converter, reduce the volume proportion occupied in the converter, further reduce the volume of the converter system, improve the power density, realize the high-efficiency and high-power density operation of the system, and improve the flexibility and the reliability of the operation.

Has the advantages that:

1. the invention discloses a transformer magnetic integration structure integrating leakage inductance and excitation inductance and an integration method thereof, aiming at a common type of transformer containing three magnetic element structures of leakage inductance, excitation inductance and a transformer, the integration among the leakage inductance, the excitation inductance and the transformer is realized by reasonably designing the winding connection mode and parameters, the number of circuit magnetic elements can be obviously increased, the integral volume of a transformer system is reduced, and the improvement of the power density index of the system is facilitated.

2. The transformer magnetic integration structure integrating leakage inductance and excitation inductance and the design method thereof disclosed by the invention use a standard UI magnetic core structure, overcome the problem of complex magnetic core structure in a common magnetic integration method, are convenient to expand the application range, are convenient to manufacture and obtain the magnetic core, improve the general applicability of the transformer magnetic integration structure, and are more convenient and effective.

3. The invention discloses a transformer magnetic integration structure integrating leakage inductance and excitation inductance and a design method thereof, wherein the control degree of freedom comprises a primary winding N of a UI magnetic core A_p1Secondary winding N of UI magnetic core A_s1Air gap l of UI core A_g1Primary winding N of UI magnetic core B_p2Secondary winding N of UI magnetic core B_s2Air gap l of UI core B_g2More control degrees of freedom can realize flexible control of the magnetic integration method, and parameters required by the operation of the converter can be met, so that the operation reliability of the converter can be improved.

4. The transformer magnetic integration structure integrating the leakage inductance and the excitation inductance and the integration method thereof disclosed by the invention are widely applied to a converter with the leakage inductance, the excitation inductance and the transformer structure, promote the converter to carry out energy transfer under high efficiency and high power density, and improve the operation reliability of the converter.

Drawings

FIG. 1 is a schematic diagram of the magnetic core structure and winding connections of the present magnetically integrated transformer;

FIG. 2 is a schematic diagram of voltage and current parameters of the magnetic integration method;

FIG. 3 is a diagram of a magnetic resistance model of the magnetic integrated transformer;

FIG. 4 is a schematic diagram of a three-dimensional structure of the magnetic integrated transformer of the present invention;

FIG. 5 is a schematic diagram of a dual-active full-bridge converter according to the present embodiment;

fig. 6 is a flowchart of a magnetic integration method for a transformer integrating leakage inductance and excitation inductance.

Detailed Description

The method disclosed by the invention will be described in detail with reference to the accompanying drawings and embodiments, which reflect the technical problems and advantages solved by the technical solutions of the invention, and it should be noted that the described embodiments are intended to facilitate understanding of the invention, but do not limit the applicability of the invention.

Example (b): the invention discloses a transformer magnetic integration structure integrating leakage inductance and excitation inductance and effectiveness and feasibility of a design method thereof by taking a common type double-active-bridge DAB converter as an example.

Fig. 5 is a schematic diagram of a magnetic integrated dual-active bridge converter according to this embodiment, where the magnetic integrated dual-active bridge converter according to the embodiment of the present invention includes a primary full bridge, a secondary full bridge, a magnetic integrated portion, a primary dc power supply, a secondary dc power supply, an input filter capacitor, and an output filter capacitor, and has good symmetry. The primary side full bridge comprises a switching device S₁Switching device S₂Switching device S₃Switching device S₄The points A and B are respectively the respective middle points of two bridge arms of the primary side active bridge, v_ABThe voltage difference between the point A and the point B is obtained; the secondary side full bridge comprises a switching device S₅Switching device S₆Switching device S₇Switching device S₈And points C and D are respectively the respective middle points of two bridge arms of the secondary side active bridge, v_CDThe voltage difference between the point C and the point D is obtained; i.e. i_pAnd i_sIs the current, V, of the primary and secondary sides of the transformer of the converter₁Is a DC voltage of a primary side, V₂Is the DC voltage of the secondary side; the magnetic integration part comprises a leakage inductance L_kAnd an exciting inductance L_mHigh frequency, high frequencyTransformer T, i_LmIs the current flowing through the excitation inductor.

Switching device S₁Is connected to the switching device S₂Of the drain electrode, the switching device S₃Is connected to the switching device S₄Of the drain electrode, the switching device S₁And a switching device S₃Is connected to the drain of the switching device S₂Source and switching device S₄Is connected to the source of the switching device S₅Is connected to the switching device S₆Of the drain electrode, the switching device S₇Is connected to the switching device S₈Of the drain electrode, the switching device S₅And a switching device S₇Is connected to the drain of the switching device S₆Source and switching device S₈The source electrodes of the first and second transistors are connected; the input filter capacitor C₁Switching device S of same primary side full bridge₁Drain electrode of (1), switching device (S)₃And a switching device S₂Source electrode of (1), switching device (S)₄The source electrodes of the first and second transistors are connected; the output filter capacitor C₂Switch device S of same secondary side full bridge₅Drain electrode of (1), switching device (S)₇And a switching device S₆Source electrode of (1), switching device (S)₈The source electrodes of the first and second transistors are connected; the primary side direct current power supply is connected with the input filter capacitor; the secondary side direct current power supply is connected with the output filter capacitor; the centers A and B of the primary side bridge arm and the primary side bridge arm of the magnetic integrated transformer structure are connected, and the centers C and D of the secondary side bridge arm and the secondary side bridge arm of the magnetic integrated transformer structure are connected.

The magnetic integrated structure adopted by the present embodiment is shown in fig. 1. With reference to fig. 1, the magnetic integration method for a transformer integrating leakage inductance and excitation inductance disclosed in this embodiment includes the following steps:

the method comprises the following steps: on the premise of realizing soft switching of all switching tubes and working of the double-active full-bridge DAB at a smaller current effective value, the required transformer parameters, namely the transformation ratio n and the leakage inductance L are determined_kExcitation inductance L_m；

Step two: obtaining a coupling inductance matrix by equivalent transformer parameters, calculating the actual transformation ratio n' of the transformer according to different transformation ratios as shown in a formula (9)Need to be able to be at R_g1＝R_g2Or R_g1≠R_g2Determining the number of winding turns N of two UI cores in both cases_p1、N_s1、N_p2、N_s2；

Step three: after the number of turns is determined, calculating the size of the magnetic resistance according to a formula (5);

step four: to prevent core saturation, the appropriate core cross-sectional area is determined based on the maximum magnetic flux at which the transformer operates.

Step 4.1: the cross-sectional area A of the UI magnetic core A is obtained_e1According to l_g1＝R_g1A_e1μ₀The air gap length l of UI core A can be determined_g1。

Step 4.2: the cross-sectional area A of the UI magnetic core B is obtained_e2According to l_g2＝R_g2A_e2μ₀The air gap length l of UI core B can be determined_g2. Thus, a two UI core transformer design is completed.

Step five: and integrating the leakage inductance and the excitation inductance of the transformer into the transformer formed by the two standard UI magnetic cores according to the transformer parameters in the step four, so as to realize the integration of the magnetic integration structure of the transformer integrating the leakage inductance and the excitation inductance. The magnetic integrated structure of the transformer can reduce the number of magnetic elements of the converter, reduce the volume proportion occupied in the converter, further reduce the volume of the converter system, improve the power density, realize the high-efficiency and high-power density operation of the system, and improve the flexibility and the reliability of the operation.

In the embodiment, the primary full bridge and the secondary full bridge of the double-active-bridge converter can adopt single phase-shift control, extended phase-shift control and the like, the primary full bridge works in an inversion state when energy is transmitted in the forward direction, the secondary full bridge works in a rectification state, the secondary full bridge works in the inversion state when energy is transmitted in the reverse direction, and the primary full bridge works in the rectification state. Primary winding N_p1And N_p2Ports 1 and 1 formed in seriesThe port 2 is respectively connected to the middle point of a bridge arm of the primary full bridge and the secondary winding N_s1And N_s2And a port 3 and a port 4 formed by series connection are respectively connected to the middle points of bridge arms of the secondary full bridge, and under the magnetic integrated structure, the magnetic integrated transformer assists the converter to realize the DAB power transmission of the double active bridges by the access of an original secondary direct-current power supply and the driving of a switching tube.

Through the analysis, the transformer capable of realizing electrical isolation of the converter can be optimized, the control freedom degree is increased, the converter can be more flexibly assisted to carry out bidirectional power transmission under the soft switch in the full load range, the volume proportion occupied by the magnetic element of the converter is reduced, and the power density of the converter is improved.

It should be noted that, the above detailed description, further elaborates the objects, technical solutions and advantages of the present invention, and the magnetic integrated structure is applied to a dual active bridge converter, and is not intended to limit the scope of the present invention to this topology, and any modifications, equivalents, improvements and the like made on the basis of the present invention shall be included in the scope of the present invention. The magnetic integrated structure and the design method of the magnetic integrated transformer can be applied to a converter containing leakage inductance, excitation inductance and the transformer, can also be applied to integration between coupling inductance and inductance, obviously improves the power density of the converter and realizes high-performance operation of the converter.