Integrated transformer
By integrating the LLC transformer and resonant inductor together, using three E-cores and PCB coil windings, the problem of independent inductors in the prior art increases the footprint and loss is solved, achieving a more efficient device design and lower loss.
Patent Information
- Application Number
- CN202421186376.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-28
- Publication Date
- 2025-03-28
- Estimated Expiration
- 2034-05-28
AI Technical Summary
The existing LLC transformers and resonant inductors exist independently, increasing the footprint and power loss, and requiring multiple E-type magnetic cores, resulting in more and more overall devices and high losses.
Design an integrated transformer to integrate the resonant inductor and transformer core, and use three E-type magnetic cores to achieve the function. The inductor winding and transformer winding are in the form of a PCB coil, and the pins are directly soldered to the printed board.
It reduces the overall number of devices, improves the use efficiency, reduces the loss of the magnetic core, and achieves good heat dissipation and simple processing technology through the design of the PCB coil.
Smart Images
Figure CN222690481U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of transformers, in particular to an integrated transformer. Background Art
[0002] LLC resonant converters have received widespread attention in industrial applications due to their high efficiency, low EMI, and ability to operate under load variations. In traditional PWM converters, the power switch tube operates in hard-switching mode, which has the problems of high switching losses and electromagnetic interference. In LLC resonant converters, the switch tube can achieve zero voltage conduction, and the output rectifier diode can also achieve zero current shutdown, thus minimizing losses and electromagnetic interference. Based on the above characteristics, LLC resonant converters are widely used in high-frequency, high-power density power conversion systems, and LLC resonant converters are the mainstream circuit topology. The transformer is one of the most important components in the LLC resonant converter. On the one hand, it can change the input / output voltage ratio, and on the other hand, it can provide electrical isolation.
[0003] At present, LLC transformers and resonant inductors generally use separate types or use the leakage inductance of the transformer as the resonant inductor, which has different advantages at different power levels. Generally, separate resonant inductors are more commonly used in medium and high power. On the one hand, they can be flexibly debugged, and on the other hand, they can increase the coupling effect of the transformer and improve the overall conversion efficiency. The disadvantage is that independent resonant inductors will increase the board space and power loss. Therefore, a new form of LLC transformer and resonant inductor is urgently needed to solve the above problems. Utility Model Content
[0004] The utility model aims to overcome the deficiencies of the prior art and provide an integrated transformer.
[0005] The purpose of the utility model is achieved through the following technical solutions: an integrated transformer, comprising a first magnetic core, a second magnetic core is arranged on one side of the first magnetic core, and a third magnetic core is arranged on the side of the second magnetic core away from the first magnetic core; the first magnetic core is a magnetic core of a resonant inductor, and the second magnetic core and the third magnetic core are both magnetic cores of a transformer; an inductor winding 1-M is arranged on the middle column of the first magnetic core, and a primary winding M-2 and a secondary winding 3-4-5 are arranged on the middle columns of the second magnetic core and the third magnetic core; the winding direction of the inductor winding 1-M is consistent with that of the primary winding M-2; a common magnetic circuit area is formed between the first magnetic core and the second magnetic core, and the magnetic circuit of the first magnetic core is opposite in direction to that of the second magnetic core.
[0006] Preferably, an inductor PCB coil is arranged inside the first magnetic core, and a transformer PCB coil is arranged inside the second magnetic core and the third magnetic core.
[0007] Preferably, the inductor pin of the inductor PCB coil is arranged on one side outside the first magnetic core.
[0008] Preferably, the transformer pins of the transformer PCB coil are arranged on one side outside the second magnetic core and / or the third magnetic core.
[0009] Preferably, the inductor pins are directly welded and mounted on a printed circuit board.
[0010] Preferably, the transformer pins are directly welded and mounted on a printed circuit board.
[0011] Preferably, the secondary winding 3-4-5 is in the form of a center tap.
[0012] The beneficial effects of the utility model are:
[0013] 1) The resonant inductor and the transformer are integrated together. The prior art generally requires four E-type magnetic cores, while the utility model only requires three E-type magnetic cores, which reduces the overall components, improves the use efficiency and can use one specification of E-type magnetic core.
[0014] 2) The magnetic circuit of the first magnetic core is in opposite directions to the magnetic circuit of the second magnetic core, which can partially or completely offset the magnetic flux of the common magnetic circuit, which is beneficial to reducing the cross-sectional area of the common magnetic circuit of the second magnetic core and reducing losses.
[0015] 3) The integrated transformer winding adopts the form of PCB coil, which can have good heat dissipation effect and simple processing technology. The pins of the coil adopt a PCB integrated structure design and can be directly soldered to the printed circuit board at the application end. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 This is the schematic diagram of LLC topology;
[0017] Figure 2 This is a schematic diagram of the integrated transformer winding;
[0018] Figure 3 It is a schematic diagram of the integrated transformer structure;
[0019] Figure 4 It is a schematic diagram of the structure of the inductor PCB coil and the transformer PCB coil. DETAILED DESCRIPTION
[0020] The following will be combined with the embodiments to clearly and completely describe the technical solution of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.
[0021] like Figure 1 As shown, in the circuit, Q1 and Q2 form a switch tube of a half-bridge structure; the resonant inductor Lr, the excitation inductor Lm of the transformer, and the resonant capacitor Cr form an LLC resonant structure, and D1 and D2 are output rectifier tubes. The utility model integrates the resonant inductor Lr and the transformer T1 together (collectively referred to as an integrated transformer) to reduce the overall components and improve the use efficiency.
[0022] See also Figure 1-Figure 4 The utility model provides a technical solution: an integrated transformer, comprising a first magnetic core, a second magnetic core is arranged on one side of the first magnetic core, and a third magnetic core is arranged on the side of the second magnetic core away from the first magnetic core; the first magnetic core is a magnetic core of a resonant inductor, and the second magnetic core and the third magnetic core are both magnetic cores of a transformer; an inductor winding 1-M is arranged on the middle column of the first magnetic core, and a primary winding M-2 and a secondary winding 3-4-5 are arranged on the middle columns of the second magnetic core and the third magnetic core; the winding direction of the inductor winding 1-M is consistent with that of the primary winding M-2; a common magnetic circuit area is formed between the first magnetic core and the second magnetic core, and the magnetic circuit of the first magnetic core is opposite to the direction of the magnetic circuit of the second magnetic core.
[0023] In this embodiment, the winding direction of the inductor winding 1-M is consistent with that of the primary winding M-2, that is, the same end is consistent. The direction of the magnetic flux generated by the inductor winding 1-M is shown in FIG. Figure 2 The magnetic flux of the inductor (Lr) and the magnetic flux generated by the primary winding M-2 of the transformer can be seen in the magnetic flux of the transformer (Lm). It can be seen that in the adjacent common magnetic circuit area of the first magnetic core and the second magnetic core, the two magnetic circuits are in opposite directions, which can partially or completely offset the magnetic flux of the common magnetic circuit, which is beneficial to reduce the cross-sectional area of the common magnetic circuit of the second magnetic core and reduce losses. The prior art generally requires four E-type magnetic cores. The utility model integrates the resonant inductor and the transformer together, and only requires three E-type magnetic cores, and can use one specification of E-type magnetic core. At the same time, compared with the prior art, the loss of the magnetic core can be significantly reduced.
[0024] In some embodiments, an inductor PCB coil is disposed inside the first magnetic core, and a transformer PCB coil is disposed inside the second magnetic core and the third magnetic core.
[0025] In some embodiments, the inductor pins of the inductor PCB coil are arranged on one side outside the first magnetic core.
[0026] In some embodiments, the transformer pins of the transformer PCB coil are arranged on one side outside the second magnetic core and / or the third magnetic core.
[0027] In some embodiments, the inductor pins are directly soldered and mounted on a printed circuit board.
[0028] In some embodiments, the transformer pins are directly soldered and mounted to a printed circuit board.
[0029] In this embodiment, the integrated transformer adopts the structure of a planar transformer, and the inductor or transformer adopts a PCB board coil, which improves the utilization rate of the winding and optimizes the board area of the integrated transformer. The first magnetic core is the magnetic core of the resonant inductor (Lr), and the second and third magnetic cores are the magnetic cores of the transformer. The first magnetic core has an inductor PCB coil, and the second and third magnetic cores have transformer PCB coils. The inductor PCB coil and the transformer PCB coil adopt the method of directly leading out the terminal of the PCB board. Figure 3 The inductor pins and transformer pins can be directly welded and installed on the printed circuit board. The structure only has a magnetic core and a PCB coil board, the structure is very simple, easy to process and assemble, and can be produced automatically. After the design is finalized, the integrated transformer has excellent machinability, high reliability, and good consistency. The integrated transformer winding adopts the form of PCB coil, which can have a good heat dissipation effect and simple processing technology. The pins of the coil adopt a PCB integrated mechanism design, which can be directly welded to the printed circuit board at the application end.
[0030] In some embodiments, the secondary winding 3-4-5 is in the form of a center tap.
[0031] The above is only a preferred embodiment of the utility model. It should be understood that the utility model is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not deviate from the spirit and scope of the utility model, and should be within the scope of protection of the claims attached to the utility model.
Claims
1. An integrated transformer, characterized in that: It includes a first magnetic core, a second magnetic core is arranged on one side of the first magnetic core, and a third magnetic core is arranged on the side of the second magnetic core away from the first magnetic core; the first magnetic core is a magnetic core of a resonant inductor, and the second magnetic core and the third magnetic core are both magnetic cores of a transformer; an inductor winding 1-M is arranged on the middle column of the first magnetic core, and a primary winding M-2 and a secondary winding 3-4-5 are arranged on the middle columns of the second magnetic core and the third magnetic core; the winding direction of the inductor winding 1-M is consistent with that of the primary winding M-2; a common magnetic circuit area is formed between the first magnetic core and the second magnetic core, and the magnetic circuit of the first magnetic core is opposite to the direction of the magnetic circuit of the second magnetic core.
2. The integrated transformer according to claim 1, characterized in that: An inductor PCB coil is arranged inside the first magnetic core, and a transformer PCB coil is arranged inside the second magnetic core and the third magnetic core.
3. The integrated transformer according to claim 2, characterized in that: The inductor pins of the inductor PCB coil are arranged on one side outside the first magnetic core.
4. The integrated transformer according to claim 2, characterized in that: The transformer pins of the transformer PCB coil are arranged on one side outside the second magnetic core and / or the third magnetic core.
5. The integrated transformer according to claim 3, characterized in that: The inductor pins are directly welded and mounted on the printed circuit board.
6. The integrated transformer according to claim 4, characterized in that: The transformer pins are directly welded and mounted on the printed circuit board.
7. The integrated transformer according to any one of claims 1 to 6, characterized in that: The secondary winding 3-4-5 is in the form of a center tap.