Magnetic integrated planar transformer

Abstract

The utility model discloses a magnetic integrated planar transformer which comprises a plurality of transformers, a resonant capacitor Cr is arranged on the left side of each transformer, three transformer middle columns are engraved and integrated on the same planar magnetic core and share an upper side column and a lower side column, and a PCB winding is arranged on each transformer middle column on the integrated magnetic core. According to the magnetic integrated planar transformer provided by the utility model, a plurality of transformers in a power supply are integrated on the same magnetic core at the same time, and a PCB (Printed Circuit Board) is used for winding, so that the size and the weight of a magnetic piece can be reduced, more space is saved in the power supply for placing other devices, and a solution is provided for improving the power density of a high-power power supply.

Description

TECHNICAL FIELD

[0001] The utility model relates to a transformer, in particular to a magnetic integrated planar transformer. BACKGROUND

[0002] In power supply system, magnetic device is important energy storage and transmission device, and is also device occupying larger space volume, although improving the switching frequency of power device in power module can reduce the size of magnetic device, but also increases switching loss, and the size reduction range of magnetic device is also limited.

[0003] For the power supply module of high-power DC / DC internal by multiple converters staggered parallel structure, it needs to pursue higher power density, and it is a great challenge to accommodate multiple larger magnetic devices in limited space.

[0004] Current processing method:

[0005] Independent device is adopted, and the resonant cavity network in LLC resonant converter is as shown in the accompanying drawing. Figure 1 Among them, the left side is resonant capacitor Cr, external resonant inductor Lr, transformer primary side excitation inductor Lm, transformer turns ratio n:1:1, secondary side inductors Ls1 and Ls2; Figure 2 It is transformer magnetic core and PCB winding schematic diagram.

[0006] This method is to use external single resonant inductor Lr and independent transformer as energy transmission magnetic device in DC / DC power converter. This scheme is convenient for circuit experiment debugging and device replacement, and is suitable for small power single converter; in high-power low-voltage large-current power supply, more power devices or multiple parallel DC / DC converters are needed, and higher requirements for the size and power density of power supply system are usually required, and the volume of power inductor and transformer magnetic core is usually large, and the limited layout space limits the use of single independent magnetic device. SUMMARY

[0007] In order to solve the problems of large number and large volume of magnetic elements in multi-phase structure power supply, the utility model provides a magnetic integrated planar transformer, which is a highly integrated magnetic element, reduces the size and weight of power converter, and reduces the cost.

[0008] The utility model provides the following technical scheme:

[0009] A magnetic integrated planar transformer contains multiple transformers, the left side of the transformer is resonant capacitor Cr, three transformer columns are engraved and integrated on the same planar magnetic core, share upper and lower side columns, and PCB winding is arranged on each transformer column on the integrated magnetic core.

[0010] Further, the magnetic integrated planar transformer is an "E-type" magnetic core structure, and the magnetic core structure is symmetrically arranged.

[0011] Further, the magnetic integrated planar transformer has a winding ratio of n:1:1.

[0012] Further, the magnetic integrated planar transformer has equal magnetic circuit lengths.

[0013] Further, the integrated magnetic core can automatically balance current, and the output current error of each phase is less than 15A, that is, the current balance degree of each phase is less than 5%.

[0014] Compared with the prior art, the magnetic integrated planar transformer has the following beneficial effects:

[0015] The magnetic integrated planar transformer integrates multiple transformers in the power supply inside the same magnetic core, utilizes PCB winding, can reduce the size and weight of the magnetic component, saves more space in the power supply for placing other components, and provides a solution for improving the power density of a high-power power supply.

[0016] 1. High power density: the "E-type" magnetic core structure integrates three transformers on a planar magnetic core through a more compact design, reduces the number and volume of magnetic components, and has a certain improvement effect on improving the power density of the power supply system.

[0017] 2. Good current balance effect: the integrated magnetic core planar transformer has equal magnetic circuit lengths, and reduces the current imbalance problem caused by magnetic resistance asymmetry. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a resonant cavity network schematic diagram of the prior art LLC resonant converter.

[0019] Figure 2 It is a transformer magnetic core and PCB winding diagram in the prior art.

[0020] Figure 3 It is a magnetic integrated planar transformer diagram of the utility model.

[0021] Figure 4 It is a transformer magnetic core and PCB winding schematic diagram of the utility model.

[0022] In the figure: 1, integrated magnetic core; 2, transformer column; 3, PCB winding. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the utility model.

[0024] The high switching frequency of the power converter provides an advantage for the use of PCB windings. In addition, the low inductance requirement brought by high frequency also makes the planar magnetic element based on the PCB winding more advantageous for integration.

[0025] In a multiphase interleaved LLC power supply system, if an independent transformer and external resonant inductor are used for each phase, a large PCB layout space will be occupied, and the wiring of the remaining devices in the system will also be limited. When two or more converters are interleaved, the present scheme can be used:

[0026] Please refer to Figure 3 and Figure 4 , the magnetic integrated planar transformer contains multiple transformers, the left side of the transformer is a resonant capacitor Cr, three transformer columns 2 are engraved and integrated on the same planar magnetic core, and the upper and lower side columns are shared, and the PCB winding 3 is arranged on each transformer column 2 on the integrated magnetic core 1.

[0027] The magnetic integrated planar transformer is an "E-type" magnetic core structure, and the magnetic core structure is symmetrically arranged.

[0028] The magnetic integrated planar transformer has a turn ratio n:1:1.

[0029] The magnetic integrated planar transformer has equal magnetic path lengths.

[0030] That is, the external resonant inductor is replaced by the leakage inductance of the transformer, and the independent transformer in each phase is integrated on the same planar magnetic core (i.e., the integrated magnetic core), and the PCB winding is arranged on each transformer column on the integrated magnetic core, thereby realizing high integration of the magnetic element, and the magnetic core structure is symmetrically designed, which is beneficial to balancing the load current of each phase and improving the efficiency and stability of the system.

[0031] The utility model provides "E-type" planar magnetic core structure based on PCB winding, three transformer columns are engraved and integrated on the magnetic core, and the upper and lower side columns are shared, thereby reducing the volume and weight of the magnetic element, improving the power density of the power supply system, and verifying the effectiveness of the scheme through detailed design, simulation and experimental debugging of the magnetic element parameters.

[0032] In this embodiment, the integrated magnetic core transformer is used in a three-phase interleaved LLC converter circuit, and the PCB winding is at each middle column of the magnetic core, which does not affect the independent operation and power output of each phase converter after replacing the original single independent transformer, and the working performance remains consistent with that of the single transformer.

[0033] The power supply system in this embodiment requires an output total current of 340A, and the integrated magnetic core can automatically current-sharing, and the output current error of each phase is less than 15A, that is, the current-sharing degree of each phase is less than 5%.

[0034] This technical solution reduces the volume and weight of the magnetic device of the power supply system, improves the flexibility of the PCB wiring layout, and the magnetic core itself also has good current-sharing performance.

[0035] Although the embodiments of the utility model have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and spirits of the utility model, and the scope of the utility model is defined by the appended claims and their equivalents.

Claims

1. A magnetically integrated planar transformer, characterized in that: It contains multiple transformers. The left side of the transformer is a resonant capacitor Cr. Three transformer columns (2) are engraved and integrated on the same planar magnetic core. They share the upper and lower side columns. Each transformer column (2) on the integrated magnetic core (1) is provided with PCB windings (3).

2. The magnetically integrated planar transformer according to claim 1, characterized in that: This magnetically integrated planar transformer has an "E-type" magnetic core structure with symmetrical arrangement of the magnetic core.

3. A magnetically integrated planar transformer according to claim 1, characterized in that: The turns ratio of this magnetically integrated planar transformer is n:1:

1.

4. A magnetically integrated planar transformer according to claim 1, characterized in that: The magnetic circuit lengths of the magnetically integrated planar transformers are equal.

5. A magnetically integrated planar transformer according to claim 1, characterized in that: This integrated magnetic core can automatically share current, with an output current error of less than 15A per phase, meaning the current sharing per phase is less than 5%.

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