Integrated planar transformer

Abstract

The utility model belongs to the technical field of planar transformers, and particularly relates to an integrated planar transformer which comprises a shielding shell, a first magnetic core, a second magnetic core, a primary winding and a secondary winding. Wherein the shielding shell is a metal shell which sleeves the outer sides of the first magnetic core and the second magnetic core and is provided with a plurality of through holes, the first magnetic core and the second magnetic core are consistent in structure arrangement, and the primary winding and the secondary winding are arranged between the first magnetic core and the second magnetic core; the first magnetic core comprises a middle column, a first side column, a second side column, a first limiting column arranged between the middle column and the first side column and a second limiting column arranged between the middle column and the second side column, and the first limiting column and the second limiting column are of a symmetrical structure; the primary winding sleeves the middle column, the secondary winding sleeves the first limiting column and the second limiting column, and wiring terminals of the primary winding and the secondary winding are arranged on the same side of the first magnetic core.

Description

Technical Field

[0001] This utility model belongs to the field of planar transformer technology, and specifically relates to an integrated planar transformer. Background Technology

[0002] The statements in this section are merely background information related to this utility model and do not necessarily constitute prior art.

[0003] In recent years, the rapid development of photovoltaic power generation and energy storage, electric vehicles and other new energy sources has continuously promoted the new energy revolution. In particular, photovoltaic power generation has developed rapidly in recent years. In photovoltaic power generation system solutions, there are two categories: high-power commercial string inverters and low-power civilian micro-inverters.

[0004] The future design trends for microinverters are high conversion efficiency; increased power, from 300W to 600W or even higher; high-frequency, high-power-density structural design; and the adoption of a full-bridge LLC topology to replace the flyback. Therefore, the magnetic components in microinverters must meet the requirements of miniaturization, high frequency, and integration.

[0005] Existing microinverter LLC topologies rely on an LLC transformer to convert the 16-70V input voltage from photovoltaic modules to 220V, which is then converted to 220V 50Hz AC via an inverter circuit. The key component of a microinverter LLC, the transformer, typically employs a flyback design, a discrete component combining a resonant inductor and an LLC transformer, or a current transformer for monitoring. However, this results in a relatively large transformer grounding area, increasing losses and creating challenging electromagnetic interference (EMI) problems. Utility Model Content

[0006] To address the aforementioned issues, this invention proposes an integrated planar transformer. By employing a magnetic core, the transformer's size is reduced. An auxiliary magnetic circuit is established within the magnetic core to increase leakage inductance, which serves as a resonant inductor. Essentially, the resonant inductor and an external current transformer are integrated into the transformer. A shielded casing is used to prevent magnetic field leakage and enhance the effectiveness against electromagnetic interference.

[0007] According to some embodiments, the first solution of this utility model provides an integrated planar transformer, which adopts the following technical solution:

[0008] An integrated planar transformer includes a shielding shell, a first magnetic core, a second magnetic core, a primary winding, and a secondary winding. The shielding shell is fitted over the first and second magnetic cores, which have identical structures. The primary and secondary windings are disposed between the first and second magnetic cores. The first magnetic core includes a magnetic plate and a central post, a first side post, a second side post, a first limiting post between the central post and the first side post, and a second limiting post between the central post and the second side post, all disposed on the same side of the magnetic plate. The central post is located in the middle of the magnetic plate, and the first and second limiting posts are symmetrical. The primary winding is disposed on the central post, and the secondary winding is disposed on the first and second limiting posts. The terminals of the primary and secondary windings are all located on the same side of the first magnetic core.

[0009] As a further technical limitation, the shape of the shielding shell matches the first magnetic core; the shielding shell is in the shape of a groove, and through holes are provided on its bottom surface and at least one side surface; a grounding pin is provided on the side surface with the through hole, and the ends of the two sides adjacent to the side surface with the grounding pin are provided with bent portions.

[0010] As a further technical limitation, the side of the first limiting post near the first side post has a convex arc-shaped structure, and the side of the second limiting post near the second side post has a convex arc-shaped structure.

[0011] As a further technical limitation, the primary winding includes a primary winding frame, a primary coil disposed on the primary winding frame, and a primary coil insulating tape disposed outside the primary coil; both the primary coil and the primary coil insulating tape are wound on the primary winding frame.

[0012] Furthermore, the primary winding frame is provided with a primary winding frame slot, and the end of the primary coil is disposed in the primary winding frame slot; the primary coil fixed in the primary winding frame slot forms the terminal of the primary winding.

[0013] As a further technical limitation, the secondary winding includes a secondary winding frame, a secondary coil disposed on the secondary winding frame, and a secondary coil insulating tape disposed outside the secondary coil; both the secondary coil and the secondary coil insulating tape are wound around the secondary winding frame.

[0014] Furthermore, the secondary winding frame is provided with a secondary winding frame slot, and the end of the secondary coil is disposed in the secondary winding frame slot; the secondary coil fixed in the secondary winding frame slot forms the terminal of the secondary winding.

[0015] Furthermore, the secondary winding frame includes a secondary coil mounting portion, and a first secondary coil limiting plate and a second secondary coil limiting plate disposed at both ends of the secondary winding frame; the secondary coil is sleeved on the secondary coil mounting portion; the second secondary coil limiting plate is provided with a snap-fit ​​portion, and a snap-fit ​​groove is opened on the snap-fit ​​portion away from the secondary coil mounting portion, and a snap-fit ​​groove is provided on the side of the snap-fit ​​portion.

[0016] Furthermore, the snap-fit ​​part is provided with a snap-fit ​​connector, which is provided with a protrusion that matches the snap-fit ​​groove and a snap-fit ​​block that snaps into the snap-fit ​​groove.

[0017] Furthermore, an integrated planar transformer also includes a current transformer disposed on the secondary winding, the current transformer being disposed on the snap-fit ​​portion.

[0018] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0019] This invention reduces the size of the transformer by using a magnetic core, establishes an auxiliary magnetic circuit (first limiting post and second limiting post) inside the magnetic core to increase leakage inductance, which is equivalent to integrating the resonant inductor into the transformer. A shielded shell is used to avoid magnetic field leakage and increase the effect of electromagnetic interference resistance. Attached Figure Description

[0020] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments of this utility model and their descriptions are used to explain this utility model and do not constitute an improper limitation of this utility model.

[0021] Figure 1 This is a schematic diagram of an overall structure of the integrated planar transformer in an embodiment of this utility model;

[0022] Figure 2 This is a schematic diagram of an integrated planar transformer in an embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the structure of the shielding shell in an embodiment of the present utility model;

[0024] Figure 4 This is a schematic diagram of the structure of the shielding shell in an embodiment of the present utility model;

[0025] Figure 5 This is a schematic diagram of the structure of the first magnetic core in an embodiment of this utility model;

[0026] Figure 6 This is a schematic diagram of a primary winding in an embodiment of the present utility model;

[0027] Figure 7 This is a schematic diagram of a primary winding in an embodiment of the present utility model;

[0028] Figure 8 This is a schematic diagram of a secondary winding structure in an embodiment of the present utility model;

[0029] Figure 9 This is a schematic diagram of a secondary winding structure in an embodiment of the present utility model;

[0030] Figure 10 This is a schematic diagram of a structure of the second-stage coil limiting plate in an embodiment of this utility model;

[0031] The components are as follows: 1. Shielding shell; 11. Grounding pin; 12. Bending part; 13. Through hole; 2. First magnetic core; 21. First side post; 22. First limiting post; 23. Middle post; 24. Second limiting post; 25. Second side post; 26. Magnetic plate; 3. Primary winding; 31. Primary winding frame; 32. Primary coil; 33. Primary coil insulating tape; 34. Primary winding frame slot; 35. Primary winding terminal; 4. Secondary winding; 41. Secondary winding frame; 411. Secondary coil. Installation section; 412, primary coil limiting plate; 413, secondary coil limiting plate; 4131, snap-fit ​​section; 41311, snap-fit ​​slot; 41312, snap-fit ​​groove; 4132, snap-fit ​​connector; 41321, protrusion; 41322, snap-fit ​​block; 42, secondary coil; 43, secondary coil insulating tape; 44, secondary winding frame slot; 45, secondary winding terminal block; 5, second magnetic core; 6, current transformer; 61, receiving slot; 62, positioning post; 63, positioning post through hole. Detailed Implementation

[0032] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0033] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0034] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to the present invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0035] In this utility model, terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", and "bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to facilitate the description of the structural relationship between the various components or elements of this utility model and do not specifically refer to any component or element in this utility model. They should not be construed as limiting this utility model.

[0036] In this utility model, terms such as "fixed connection," "connected," and "joined" should be interpreted broadly, indicating a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in this utility model can be determined according to the specific circumstances, and should not be construed as a limitation of this utility model.

[0037] Example

[0038] This utility model embodiment introduces an integrated planar transformer.

[0039] like Figure 1 and Figure 2 An integrated planar transformer is shown, comprising a shielded housing 1, a first magnetic core 2, a primary winding 3, a secondary winding 4, a second magnetic core 5, and a current transformer 6.

[0040] The following implementation details each component with its structural diagram.

[0041] like Figure 3 and Figure 4 The shielding shell 1 shown has several through holes 13 on its top surface and on both sides in the width direction. A grounding pin 11 is connected to the longer side. Bending parts 12 are provided on both sides of the top surface and both sides in the length direction. Each bending part 12 can be bent and moved along the corresponding connected top surface or side edge.

[0042] In this embodiment, the shielding shell 1 is made of metal.

[0043] To enhance the overall electromagnetic interference resistance of the transformer, this embodiment grounds the magnetic core and the shielding shell 1, that is, the shielding shell 1, the first magnetic core 2 and the second magnetic core 5 are connected by conductive adhesive.

[0044] In this embodiment, when electromagnetic waves encounter the shielding shell 1, most of the electromagnetic waves are reflected back, and only a very small portion penetrates the shielding shell 1 or is absorbed on the surface of the shielding shell 1. Based on the reflection and absorption effects, the shielding shell 1 forms a protective cover that can shield electromagnetic wave interference; thereby protecting the electronic equipment or system inside the transformer from external electromagnetic wave interference, preventing electromagnetic radiation, effectively preventing the electromagnetic field of the transformer from radiating into the surrounding space, avoiding interference with nearby electrical equipment, and ensuring the normal operation of the electrical equipment.

[0045] This embodiment takes the first magnetic core 2 as an example for introduction. The structure of the second magnetic core 5 is completely the same as that of the first magnetic core 2, and will not be described again in this embodiment.

[0046] like Figure 5 The first magnetic core 2 shown includes a magnetic plate 26 and a first side post 21, a first limiting post 22, a middle post 23, a second limiting post 24, and a second side post 25 disposed on the magnetic plate 26. The first limiting post 22 and the second limiting post 24 are sequentially connected between the first side post 21 and the middle post 23 and between the second side post 25 and the middle post 23. By adding the first limiting post 22 and the second limiting post 24, which are arranged in a symmetrical structure, the first limiting post 22 and the second limiting post 24 serve as auxiliary magnetic circuits to increase the magnetic circuit. In this embodiment, the first limiting post 22 and the second limiting post 24 have an arc-shaped structure, and the side away from the middle post 23 has a convex arc-shaped structure. In other embodiments, the auxiliary magnetic circuit can adopt other shapes and structures.

[0047] like Figure 6 and Figure 7 The primary winding 3 shown includes a primary winding frame 31, a primary coil 32, a primary coil insulating tape 33, and a primary winding frame slot 34; wherein, the end of the primary coil 32 is wound in the primary winding frame slot 34 and then fixed by adhesive, thereby forming a primary winding terminal 35.

[0048] It should be noted that the primary winding 3 is located on the middle column 23.

[0049] In this embodiment, the primary coil 32 is wound in a single layer on the primary winding skeleton slot 34.

[0050] The structure of the primary winding 3 in this embodiment is as follows: Figure 7 As shown, the primary coil 32 is wound around the primary winding frame 31, and then the primary coil insulating tape 33 is placed on the outside of the primary coil 32 to insulate the primary coil 32.

[0051] It should be noted that the specific structure of the primary winding frame 31 in this embodiment is similar to that of the secondary winding frame 41, both of which are provided with two limiting plates; the structure of the secondary winding frame 41 will be described in detail in this embodiment, and will not be repeated here.

[0052] like Figure 8 and Figure 9 The secondary winding 4 shown includes a secondary winding frame 41, a secondary coil 42, a secondary coil insulating tape 43, and a secondary winding frame slot 44; the end of the secondary coil 42 is wound in the secondary winding frame slot 44 and then fixed by adhesive, thereby forming a secondary winding terminal 45.

[0053] It should be noted that, for the convenience of using the transformer, the primary winding terminal 35 and the secondary winding terminal 45 need to be located on the same side of the first magnetic core 2 and the second magnetic core 5.

[0054] It should be noted that the secondary winding 4 is located within the accommodating space formed by the first limiting post 22, the middle post 23, and the second limiting post 24.

[0055] In this embodiment, the secondary coil 42 is wound in two layers on the secondary winding frame 41; in other embodiments, the secondary coil 2 can be wound in multiple layers on the secondary winding frame 41.

[0056] like Figure 9 As shown, the secondary coil 42 is wound around the secondary winding frame 41, and then the secondary coil insulating tape 43 is wrapped around the outside of the secondary coil 42 to insulate the secondary coil 42.

[0057] It should be noted that the secondary winding frame 41 includes a secondary coil mounting portion 411, and a primary coil limiting plate 412 and a secondary coil limiting plate 413 disposed on the secondary coil mounting portion 411; the secondary coil 42 is wound on the secondary coil mounting portion 411; the secondary coil limiting plate 413 is provided with a snap-fit ​​portion 4131; as shown Figure 10 As shown, a slot 4131 is provided on the snap-fit ​​part 4131 on the side away from the secondary coil mounting part 411, and a snap-fit ​​groove 41312 is provided on the side of the snap-fit ​​part 4131; a snap-fit ​​connector 4132 is snap-fitted on the snap-fit ​​part 4131, and the snap-fit ​​connector 4132 is provided with a protrusion 41321 that matches the slot 41311 and a snap-fit ​​block 41322 that snaps into the slot 41312;

[0058] In use, the secondary coil 42 is wound around the secondary coil mounting part 411, and the ends of the secondary coil 42 are placed in the slots 41311. Then, the snap-fit ​​block 41322 is snapped into the slot 41312. At this time, the protrusion 41321 extends into the slot 41311 and exerts a certain squeezing and fixing effect on the ends of the secondary coil 42. It can be understood that the snap-fit ​​block 41322 is set on the snap-fit ​​connector 4132 by a flexible side plate.

[0059] like Figure 9 As shown, the snap-fit ​​part 4131 is provided with a receiving groove 61 for accommodating the current transformer 6. A positioning post 62 is provided in the receiving groove 61. A positioning post through hole 63 is opened in the middle of the positioning post 62. The primary coil 32 or the secondary coil 42 passes through the positioning post through hole 63 to connect with the current transformer 6. In this embodiment, a magnetic ring wire is used. One of the output wires is selected, and the output part is used as 1 turn. The magnetic ring is wound with n turns as the output end to realize the conversion of large current to small current, thereby monitoring the current.

[0060] This invention reduces the size of the transformer by using a magnetic core, establishes an auxiliary magnetic circuit (first limiting post 22 and second limiting post 24) inside the magnetic core to increase leakage inductance, and uses a shielded shell to avoid magnetic field leakage, thereby increasing the effectiveness of electromagnetic interference resistance.

[0061] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

[0062] Although the specific embodiments of the present utility model have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present utility model. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solution of the present utility model are still within the scope of protection of the present utility model.

Claims

1. An integrated planar transformer, characterized in that, The device includes a shielding shell, a first magnetic core, a second magnetic core, a primary winding, and a secondary winding. The shielding shell is fitted over the first and second magnetic cores, which have identical structures. The primary and secondary windings are disposed between the first and second magnetic cores. The first magnetic core includes a magnetic plate and a central post, a first side post, a second side post, a first limiting post between the central post and the first side post, and a second limiting post between the central post and the second side post, all disposed on the same side of the magnetic plate. The central post is located in the middle of the magnetic plate, and the first and second limiting posts are symmetrical. The primary winding is disposed on the central post, and the secondary winding is disposed on the first and second limiting posts. The terminals of the primary and secondary windings are all located on the same side of the first magnetic core.

2. An integrated planar transformer as described in claim 1, characterized in that, The shape of the shielding shell matches the first magnetic core; the shielding shell is in the shape of a groove, and through holes are provided on its bottom surface and at least one side surface; a grounding pin is provided on the side surface with the through hole, and the ends of the two sides adjacent to the side surface with the grounding pin are provided with bent portions.

3. An integrated planar transformer as described in claim 1, characterized in that, The side of the first limiting post near the first side post has a convex arc-shaped structure, and the side of the second limiting post near the second side post has a convex arc-shaped structure.

4. An integrated planar transformer as described in claim 1, characterized in that, The primary winding includes a primary winding frame, a primary coil disposed on the primary winding frame, and primary coil insulating tape disposed outside the primary coil; both the primary coil and the primary coil insulating tape are wound on the primary winding frame.

5. An integrated planar transformer as described in claim 4, characterized in that, The primary winding frame is provided with a primary winding frame slot, and the end of the primary coil is disposed in the primary winding frame slot; the primary coil fixed in the primary winding frame slot forms the terminal of the primary winding.

6. An integrated planar transformer as described in claim 1, characterized in that, The secondary winding includes a secondary winding frame, a secondary coil disposed on the secondary winding frame, and a secondary coil insulating tape disposed outside the secondary coil; both the secondary coil and the secondary coil insulating tape are wound around the secondary winding frame.

7. An integrated planar transformer as described in claim 6, characterized in that, The secondary winding frame is provided with a secondary winding frame slot, and the end of the secondary coil is disposed in the secondary winding frame slot; the secondary coil fixed in the secondary winding frame slot forms the terminal of the secondary winding.

8. An integrated planar transformer as described in claim 7, characterized in that, The secondary winding frame includes a secondary coil mounting part, and a first secondary coil limiting plate and a second secondary coil limiting plate disposed at both ends of the secondary winding frame; the secondary coil is sleeved on the secondary coil mounting part; the second secondary coil limiting plate is provided with a snap-fit ​​part, and a snap-fit ​​groove is opened on the snap-fit ​​part away from the secondary coil mounting part, and a snap-fit ​​groove is provided on the side of the snap-fit ​​part.

9. An integrated planar transformer as described in claim 8, characterized in that, The snap-fit ​​part is provided with a snap-fit ​​connector, which has a protrusion that matches the snap-fit ​​groove and a snap-fit ​​block that snaps into the snap-fit ​​groove.

10. An integrated planar transformer as described in claim 8, characterized in that, It also includes a current transformer disposed on the secondary winding, the current transformer being disposed on the snap-fit ​​portion.

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