CN-122025373-A - Integrated magnetic element based on side column asymmetry and design method thereof

CN122025373ACN 122025373 ACN122025373 ACN 122025373ACN-122025373-A

Abstract

An integrated magnetic element based on side column asymmetry and a design method thereof solve the problems of reducing cost and improving power density of a power supply, and belong to the technical field of magnetic integration. The magnetic core comprises a first side column, a second side column and a middle column positioned between the first side column and the second side column, wherein the structures of the first side column and the second side column are asymmetric, the transformer winding is wound on the middle column, the resonant inductance winding comprises a first inductance winding wound on the first side column and a second inductance winding wound on the second side column, air gaps are arranged on the first side column, the second side column and the middle column, and the magnetic resistance of the first side column, the magnetic resistance of the second side column, the number of turns of the first inductance winding and the number of turns of the second inductance winding are configured to meet decoupling conditions, so that magnetic fluxes generated by the first inductance winding and the second inductance winding on the middle column cancel each other, and magnetic decoupling with the transformer winding is achieved.

Inventors

GUAN LESHI
WEN YAOFU
Na Yingsi
WANG YIJIE
XU DIANGUO

Assignees

哈尔滨工业大学

Dates

Publication Date: 20260512
Application Date: 20260310

Claims (10)

1. An integrated magnetic component based on side column asymmetry is characterized by comprising a magnetic core, a transformer winding and a resonant inductance winding: The magnetic core comprises a first side column, a second side column and a middle column positioned between the first side column and the second side column, and the structures of the first side column and the second side column are asymmetric; winding a transformer winding on the center post; The resonant inductance winding comprises a first inductance winding wound on the first side column and a second inductance winding wound on the second side column; The first side column, the second side column and the middle column are all provided with air gaps; The reluctance of the first leg, the reluctance of the second leg, the number of turns of the first inductor winding, and the number of turns of the second inductor winding are configured to satisfy a decoupling condition such that magnetic fluxes generated by the first inductor winding and the second inductor winding on the center leg cancel each other out, thereby achieving magnetic decoupling with the transformer winding.
2. The integrated magnetic component of claim 1, wherein the decoupling condition is: Wherein, the 、 The number of turns of the first and second inductive windings respectively, 、 The length of the air gap of the first side column and the second side column is respectively, 、 The magnetic path sectional areas of the first side column and the second side column are respectively, Indicating the permeability of air.
3. The integrated magnetic component of claim 1, wherein the first inductive winding and the second inductive winding are connected in parallel, the number of turns of the first inductive winding and the second inductive winding is kept constant, and the ratio of the magnetic circuit cross-sectional area of the first leg and the second leg to the air gap length is kept constant, such that the inductance values of the first leg and the second leg are equal and the winding currents are consistent, while the decoupling condition is still satisfied.
4. The method for designing an integrated magnetic component based on side pillar asymmetry of claim 2, comprising: S1, determining electrical parameters according to an application scene to obtain a transformer transformation ratio, a target excitation inductance value and a target resonance inductance value; S2, selecting a magnetic core material, and determining a material parameter; S3, determining magnetic circuit sectional areas of the first side column, the second side column and the middle column based on the target excitation inductance value, the target resonance inductance and the material parameters; s4, designing the wire diameter, the number of turns and the arrangement mode of the first inductance winding and the second inductance winding and the length of the air gaps of the first side column and the second side column according to decoupling conditions, so that the resonant inductor is decoupled from the magnetic circuit of the transformer; s5, designing the wire diameter, the number of turns, the arrangement mode and the air gap length of a center post of a transformer winding by combining the transformer transformation ratio and the target excitation inductance value based on the magnetic circuit cross section area determined in the S3 and the air gap length designed in the S4; s6, verifying whether the actual excitation inductance meets the target excitation inductance value and whether the actual resonance inductance meets the target resonance inductance value through theoretical calculation or simulation, if yes, switching to S7, and if not, switching to S4 to readjust the air gap lengths of the first side column and the second side column; S7, determining the height of a magnetic core window according to the wire diameters, turns and arrangement modes of the first inductance winding, the second inductance winding and the transformer winding, and selecting an adaptive magnetic core specification; s8, calculating magnetic core loss, winding loss and maximum magnetic flux density based on the current design scheme, judging whether the performance requirements in practical application are met, if not, switching to S3 to readjust the magnetic path sectional area, and if so, integrating all parameters to form a complete integrated magnetic element design scheme.
5. The method of designing according to claim 4, wherein the electrical parameters include resonant frequency, input voltage, output voltage and power specification of the LLC resonant converter; The transformer transformation ratio is set according to input voltage and output voltage, and the target excitation inductance value and the target resonance inductance value are determined according to resonance frequency, power specification and soft switching conditions.
6. The method of claim 4, wherein the magnetic flux generated by the first inductor winding on the first leg and the magnetic flux generated by the transformer winding cancel each other, the magnetic flux generated by the second inductor winding on the second leg and the magnetic flux generated by the transformer winding overlap each other, and the maximum magnetic flux density of the second leg is: Representing the maximum magnetic flux co-generated by the inductive windings on the two legs; maximum magnetic flux generated on the center post for the transformer winding; Is that Magnetic flux generated on the second inductance winding at the moment; ; ; 、 Values of the first and second inductive windings, respectively; a peak current generated on the two inductance windings; Outputting a voltage for the converter; Turns of secondary winding in transformer winding, LLC resonant converter To the point of The resonant inductance L r and the resonant capacitance C r are in binary resonance in a period of time, and the exciting inductance L m is clamped at the output voltage ; According to the obtained maximum magnetic flux density of the second side column, in S3 and S4, the air gap length and the magnetic path cross section area of the first side column are modified, so that the utilization rate of the magnetic core is improved, the larger power density is obtained, and the magnetic flux density on the first side column is ensured not to exceed the magnetic flux density of the second side column.
7. The method according to claim 6, wherein in S3 and S4, the first side column and the second side column are asymmetrically designed on the premise that the decoupling condition is satisfied and the magnetic fluxes of the first side column and the second side column are kept equal in magnitude: The magnetic path cross section of the first side column is reduced, and meanwhile, the air gap length of the first side column is correspondingly adjusted to maintain the magnetic resistance of the first side column unchanged, so that the magnetic flux density of the first side column is increased, the magnetic flux density of the second side column is kept unchanged or is changed to be smaller than a preset threshold value, and therefore the magnetic core volume is reduced and the power density is improved on the premise that decoupling conditions and inductance values are kept unchanged.
8. The method of designing according to claim 6, wherein the values of the first inductance winding and the second inductance winding are respectively: 。
9. The method of claim 6, wherein the exciting inductance has a value of: Wherein R 1 、R 2 and R 3 are magnetic resistances on the first side column, the second side column and the middle column respectively, Is the number of turns of the primary winding in the transformer winding.
10. The design method according to claim 4, wherein S5 comprises adopting planar winding process for the transformer windings, and adopting layered arrangement or staggered arrangement structure for winding arrangement to reduce parasitic capacitance; The number of turns of the primary winding and the secondary winding is set according to the transformer transformation ratio and the target excitation inductance value; And the air gap length of the middle column is calculated and determined according to the target excitation inductance value, and is cooperatively optimized with the air gap lengths of the first side column and the second side column, so that the air gap length of the middle column is smaller than the air gap lengths of the first side column and the second side column.

Description

Integrated magnetic element based on side column asymmetry and design method thereof Technical Field The invention relates to an integrated magnetic element based on side column asymmetry and a design method thereof, belonging to the technical field of magnetic integration. Background The LLC resonant converter can remarkably reduce switching loss and improve energy conversion efficiency by virtue of the zero-voltage switching characteristic of the full-load range, and is widely applied to scenes with high requirements on energy efficiency and power density, such as high-frequency power supplies, fast charging adapters and the like. The premise of high-efficiency operation is that the parameters of the resonant cavity are precisely matched, and the resonant inductor is a core element which forms an LLC resonant network and realizes the resonant function, so that the key effects of adjusting the resonant frequency, optimizing the energy transmission and maintaining the soft switching characteristic are achieved. Along with the improvement of miniaturization and integration requirements of power equipment, the planar transformer has the advantages of small volume, good heat dissipation and regular layout due to the adoption of a combined structure of the PCB winding and the thin magnetic core, and gradually becomes the main stream choice of the LLC converter, but the inherent structural characteristics of the planar transformer enable leakage inductance and excitation inductance of the planar transformer to not meet the requirement of resonance working conditions, so that the planar transformer needs to be additionally connected with independent resonance inductors in series. In order to solve the defect of adopting discrete devices and meet the high-efficiency, compact and stable operation requirements of LLC converters, the design of the magnetic integration resonant inductor becomes a necessary choice. The resonant inductor and the planar transformer are integrated in the same magnetic core structure, so that the power density of the power supply can be further improved. Common magnetic integration schemes often cannot be used on common magnetic cores, and production cost is increased. Disclosure of Invention Aiming at the problems of reducing the cost and improving the power density of a power supply, the invention provides an integrated magnetic element based on side column asymmetry and a design method thereof. The invention discloses an integrated magnetic element based on side column asymmetry, which comprises a magnetic core, a transformer winding and a resonant inductance winding: The magnetic core comprises a first side column, a second side column and a middle column positioned between the first side column and the second side column, and the structures of the first side column and the second side column are asymmetric; winding a transformer winding on the center post; The resonant inductance winding comprises a first inductance winding wound on the first side column and a second inductance winding wound on the second side column; The first side column, the second side column and the middle column are all provided with air gaps; The reluctance of the first leg, the reluctance of the second leg, the number of turns of the first inductor winding, and the number of turns of the second inductor winding are configured to satisfy a decoupling condition such that magnetic fluxes generated by the first inductor winding and the second inductor winding on the center leg cancel each other out, thereby achieving magnetic decoupling with the transformer winding. Preferably, the decoupling conditions are: Wherein, the 、The number of turns of the first and second inductive windings respectively,、The length of the air gap of the first side column and the second side column is respectively,、The magnetic path sectional areas of the first side column and the second side column are respectively,Indicating the permeability of air. Preferably, the first inductance winding and the second inductance winding are connected in parallel, the number of turns of the first inductance winding and the second inductance winding is kept constant, and the ratio of the magnetic path cross-sectional area of the first side post and the second side post to the air gap length is kept unchanged, so that the inductance values of the first side post and the second side post are equal and the winding currents are consistent, and the decoupling condition is still satisfied. The invention also provides a design method of the integrated magnetic element based on side column asymmetry all the time, which comprises the following steps: S1, determining electrical parameters according to an application scene to obtain a transformer transformation ratio, a target excitation inductance value and a target resonance inductance value; S2, selecting a magnetic core material, and determining a material parameter; S3, determining magnetic circuit sectiona