Bidirectional conversion transformer

Abstract

The utility model discloses a bidirectional conversion transformer which is characterized by comprising a base, a first framework arranged on the base, two main transformer magnetic cores and a main transformer coil which are arranged on the first framework, second frameworks symmetrically arranged on the two sides of the first framework, and harmonic transformer magnetic cores and resonance coils which are arranged on the second frameworks, a plurality of terminals are arranged at the bottom of the base, the main transformer magnetic core and the harmonious transformer magnetic core are combined to form a CLLC magnetic integration structure, and a resonant inductor and a resonant capacitor are formed on the two sides of the bidirectional conversion transformer through the combination of the harmonious transformer magnetic core and the resonant coil on the second framework. By adding the resonant capacitor to the secondary side, the transformer has the excellent characteristics of bidirectional buck-boost and soft switching on the basis of keeping the excellent characteristics of ILC, the problems of low circuit operation efficiency and large energy loss caused by certain difference of circuit topology when the transformer works bidirectionally can be solved, and the requirements of OBC application occasions are met.

Description

Technical Field

[0001] The utility model relates to the technical field of transformers, in particular to a bidirectional conversion transformer. Background Art

[0002] Due to the advantages of electric vehicles such as zero emission, low noise and sustainable development, the electric vehicle industry has developed rapidly under the encouragement of national policies. In more and more occasions, on-board chargers need to realize the traditional charging function and also discharge the lithium battery as an energy storage system in reverse. This on-board charger that realizes bidirectional power transmission has a wide range of applications. However, in the DC / DC application of on-board chargers, the circuit topology of ordinary bidirectional LLC resonant converters is different when working in forward and reverse directions, and symmetry and uniformity cannot be guaranteed. In addition, when working in bidirectional directions, the soft switching characteristics of ZVS and ZCS cannot be maintained. The circuit operation efficiency is low and the energy loss is large, especially when the battery changes with the storage capacity, because the battery terminal voltage will have a wide range of changes, resulting in insufficient gain range of ordinary bidirectional LLC resonant converters, which ultimately limits the application of OBC. Summary of the invention

[0003] In order to solve certain technical problems existing in the prior art, the purpose of this application is to provide a bidirectional conversion transformer. By adding a resonant capacitor to the secondary side, it has the excellent characteristics of bidirectional buck-boost and soft switching while maintaining the excellent characteristics of ILC. It can solve the problem of low circuit operation efficiency and large energy loss caused by certain differences in circuit topology when the transformer works in both directions, and meet the needs of OBC application scenarios.

[0004] In order to solve the above existing technical problems, this application adopts the following technical solutions:

[0005] A bidirectional conversion transformer comprises a base, a first frame arranged on the base, two main transformer cores and a main transformer coil arranged on the first frame, a second frame symmetrically arranged on both sides of the first frame, a harmonic transformer core and a resonant coil arranged on the second frame, a plurality of terminals are arranged at the bottom of the base, the main transformer core and the harmonic transformer core are combined to form a CLLC magnetic integrated structure, and a resonant inductor and a resonant capacitor are formed on both sides of the bidirectional conversion transformer through the combination of the harmonic transformer core and the resonant coil on the second frame.

[0006] Preferably, a first winding groove is provided on the first skeleton, a winding limiting groove is provided at the bottom of the first limiting groove, and the winding position and number of turns of the main transformer coil are controlled by the winding limiting groove.

[0007] Preferably, a second winding groove is provided on the second frame, and the resonant coil is arranged in the second winding groove.

[0008] Preferably, the bottoms of the first frame and the second frame are both provided with limiting structures, and the first frame and the second frame are fixed to the base through the limiting structures.

[0009] Preferably, the limiting structure includes hooks disposed at the bottom of the first frame and the second frame and with both ends bent downward, and blocks with protrusions disposed on both sides of the base and matching with the hooks.

[0010] Preferably, a supporting plate extending outward is provided at the bottom of the first skeleton and the second skeleton, the bottom of the main transformer core and the harmonic transformer core are supported by the supporting plate, and the width of the hook is increased by the support.

[0011] Preferably, a through hole is provided in the middle of the base, and downwardly protruding limiting blocks are provided at the bottom of the first frame and the second frame, and one side of the limiting block is in contact with the side wall of the through hole.

[0012] Compared with the prior art, the beneficial effects of the present invention are:

[0013] 1. In the DC / DC application of on-board chargers, compared with the traditional unidirectional converter, it can maintain the soft switching characteristics of ZVS and ZCS when working in both directions, ensuring the high-efficiency operation of the circuit, which is of great significance for energy saving and environmental protection;

[0014] Second, when the battery changes with the amount of electricity stored, the battery terminal voltage will have a wider range of changes. After improvement, the converter can have a wider gain range, thus meeting the needs of various OBC applications.

[0015] 3. Compared with the ordinary bidirectional LLC resonant converter, a resonant inductor and a resonant capacitor are symmetrically added on both sides of the first skeleton, and the parameters of the resonant inductor and the resonant capacitor are consistent, thereby ensuring the complete symmetry of the converter. Regardless of whether it is working in the forward or reverse direction, the circuit topology can ensure symmetry, the forward and reverse characteristics of the circuit are completely consistent, and both can achieve buck-boost and soft switching; thereby solving the problems of low circuit operation efficiency and large energy loss when working in both directions. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of a semi-assembled structure when the main transformer coil and the resonant coil are not installed in the utility model;

[0017] Figure 2 This is a schematic diagram of the combined structure when the main transformer coil and the resonant coil are not installed in the utility model;

[0018] Figure 3It is a schematic diagram of the structure of the second frame of the utility model, showing the structure of the support plate;

[0019] In the figure: 1. base; 2. second frame; 3. second winding groove; 4. first frame; 5. first winding groove; 6. winding limit groove; 7. main transformer core; 8. harmonic transformer core; 9. limit structure; 10. hook; 11. block; 12. through hole; 13. terminal; 14. limit block; 15. support plate. DETAILED DESCRIPTION

[0020] Below, the present application is further described in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form a new embodiment.

[0021] In the description of the present application, it should be understood that the terms "up", "down", "left", "right", etc., indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present application.

[0022] The terms "first", "second", etc. in this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0023] like Figure 1 and Figure 2 As shown, a bidirectional conversion transformer comprises a base 1, a first skeleton 4 arranged on the base 1, two main transformer cores 7 and a main transformer coil arranged on the first skeleton 4, a second skeleton 2 symmetrically arranged on both sides of the first skeleton 4, a harmonic transformer core 8 and a resonant coil arranged on the second skeleton 2, a plurality of terminals 13 are arranged at the bottom of the base 1, the main transformer core 7 and the harmonic transformer core 8 are combined to form a CLLC magnetic integrated structure, and the two sides of the bidirectional conversion transformer are combined through the second skeleton 2 and the harmonic transformer core 8 and the resonant coil to form a resonant inductor and a resonant capacitor.

[0024] During the use of time, the bidirectional conversion transformer transforms the ordinary bidirectional LLC resonant converter into a bidirectional conversion transformer with a CLLC magnetic integrated structure according to the resonant inductor and resonant capacitor structure on both sides, so that it has the excellent characteristics of bidirectional buck-boost and soft switching, and maintains the excellent characteristics of the ILC resonant converter, which can solve the problem of low circuit operation efficiency and large energy loss caused by certain differences in circuit topology when the transformer works in both directions, and meet the needs of OBC applications. Especially in the DC / DC application in the field of on-board chargers, compared with the traditional unidirectional converter, when working in both directions, it can maintain the soft switching characteristics of ZVS and ZCS, ensuring the high-efficiency operation of the circuit, which is of great significance for energy conservation and environmental protection; when the battery changes with the storage capacity, the battery terminal voltage will have a wider range of changes. After improvement, the converter can have a wider gain range, thereby meeting the needs of various OBC applications.

[0025] Compared with the ordinary bidirectional LLC resonant converter, a resonant inductor and a resonant capacitor are symmetrically added on both sides of the first skeleton 4, and the parameters of the resonant inductor and the resonant capacitor are consistent, thereby ensuring the complete symmetry of the converter. Regardless of whether it is working in the forward or reverse direction, the circuit topology can ensure symmetry, the forward and reverse characteristics of the circuit are completely consistent, and both can achieve buck-boost and soft switching; thereby solving the problems of low circuit operation efficiency and large energy loss when working in both directions.

[0026] As a further improvement, a first winding groove 5 is provided on the first skeleton 4 , a winding limiting groove 6 is provided at the bottom of the first limiting groove, and the winding position and number of turns of the main transformer coil are controlled by the winding limiting groove 6 .

[0027] The first winding groove 5 can be used to limit the installation of the main transformer core 7 and the main transformer coil, especially a winding limit groove 6 is formed at the bottom of the first limit groove. The winding position and number of turns of the main transformer coil can be accurately controlled through the winding limit groove 6, thereby avoiding the phenomenon of too much or too little winding.

[0028] A further improvement is that a second winding groove 3 is provided on the second frame 2 , and the resonant coil is arranged in the second winding groove 3 .

[0029] The second winding groove 3 can be used to limit the installation of the resonant coil to avoid affecting the performance of the resonant inductor or the resonant capacitor.

[0030] As a further improvement, the bottoms of the first frame 4 and the second frame 2 are both provided with limiting structures 9 , and the first frame 4 and the second frame 2 are fixed to the base 1 via the limiting structures 9 .

[0031] It can make the first frame 4 and the second frame 2 easier and more convenient to fix to the base 1, and easier to assemble and disassemble.

[0032] As a further improvement, the limiting structure 9 includes a hook 10 disposed at the bottom of the first frame 4 and the second frame 2 and with both ends bent downward, and a block 11 protruding and arranged on both sides of the base 1 and matching with the hook 10 .

[0033] The downwardly bent hook 10 can relatively fix the blocks 11 protruding on both sides of the seat, so that the left and right and up and down positions of the two can be limited after installation to avoid separation of the two. Moreover, when disassembling and assembling, the front and back movements are adopted, and the overall structure has a higher fit.

[0034] Further improvement is as follows: Figure 3 As shown, the bottom of the first frame 4 and the second frame 2 is provided with a support plate 15 extending outward, the bottom of the main transformer core 7 and the harmonic transformer core 8 are supported by the support plate 15, and the width of the hook 10 is increased by the support.

[0035] Since the main transformer core 7 and the harmonious transformer core 8 are prone to tilting after installation, a support plate 15 extending outward is formed at the bottom of the first frame 4 and the second frame 2, so that after the main transformer core 7 and the harmonious transformer core 8 are installed, the bottom can be supported by the support plate 15, so that the installation stability of the main transformer core 7 and the harmonious transformer core 8 is better, especially the width of the hook 10 is increased through support, which can make the hook 10 more secure when connected.

[0036] As a further improvement, a through hole 12 is provided in the middle of the base 1 , and a downwardly protruding limit block 14 is provided at the bottom of the first frame 4 and the second frame 2 , and one side of the limit block 14 is in contact with the side wall of the through hole 12 .

[0037] The through hole 12 design can effectively reduce the overall weight of the base 1 while improving the overall heat dissipation effect. Combined with the downwardly protruding limit block 14 located at the bottom of the first frame 4 and the second frame 2, the installation position between the base 1 and the first frame 4 and the second frame 2 can be made more accurate and stable.

[0038] The above-mentioned implementation modes are only preferred implementation modes of the present application and cannot be used to limit the scope of protection of the present application. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present application shall fall within the scope of protection required by the present application.

Claims

1. A bidirectional conversion transformer, characterized in that: The invention comprises a base (1), a first frame (4) arranged on the base (1), two main transformer cores (7) and a main transformer coil arranged on the first frame (4), a second frame (2) symmetrically arranged on both sides of the first frame (4), a harmonic transformer core (8) and a resonant coil arranged on the second frame (2), a plurality of terminals (13) being arranged at the bottom of the base (1), the main transformer core (7) and the harmonic transformer core (8) being combined to form a CLLC magnetic integrated structure, and the two sides of the bidirectional conversion transformer being combined through the second frame (2) and the harmonic transformer core (8) and the resonant coil to form a resonant inductor and a resonant capacitor.

2. A bidirectional conversion transformer according to claim 1, characterized in that: A first winding groove (5) is provided on the first frame (4), a winding limiting groove (6) is provided at the bottom of the first limiting groove, and the winding position and number of turns of the main transformer coil are controlled by the winding limiting groove (6).

3. A bidirectional conversion transformer according to claim 2, characterized in that: The second frame (2) is provided with a second winding groove (3), and the resonant coil is arranged in the second winding groove (3).

4. A bidirectional conversion transformer according to any one of claims 1 to 3, characterized in that: The bottoms of the first frame (4) and the second frame (2) are both provided with limiting structures (9), and the first frame (4) and the second frame (2) are fixed on the base (1) via the limiting structures (9).

5. A bidirectional conversion transformer according to claim 4, characterized in that: The limiting structure (9) comprises a hook (10) disposed at the bottom of the first frame (4) and the second frame (2) and having two ends bent downward, and a block (11) protruding on both sides of the base (1) and matching with the hook (10).

6. A bidirectional conversion transformer according to claim 5, characterized in that: A support plate (15) extending outward is provided at the bottom of the first frame (4) and the second frame (2); the bottoms of the main transformer core (7) and the harmonic transformer core (8) are supported by the support plate (15); and the width of the hook (10) is increased by the support.

7. A bidirectional conversion transformer according to claim 6, characterized in that: A through hole (12) is provided in the middle of the base (1), and downwardly protruding limit blocks (14) are provided at the bottom of the first frame (4) and the second frame (2), with one side of the limit block (14) being in contact with the side wall of the through hole (12).

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