LLC transformer with reduced copper loss

Abstract

The embodiment of the present specification discloses an LLC transformer with reduced copper loss, which adopts a full-wave rectification structure, the full-wave rectification structure is configured with a group of coils wound on a transformer magnetic core skeleton, and is adapted with a 80V patch rectification MOSFET. The embodiment of the present specification optimizes the rectification structure and the component selection, effectively reduces the coil impedance and the copper loss, reduces the voltage stress and the loss of the rectification MOSFET, at the same time, reduces the volume of the transformer, improves the heat dissipation effect, and meets the use requirement of the high power density power supply.

Description

Technical Field

[0001] This utility model relates to the field of transformer technology, and in particular to an LLC transformer that reduces copper losses. Background Technology

[0002] In the field of high-power power supplies, high-power-density power supplies are an important research and development direction. As a core component of power supplies, the LLC transformer's performance directly affects the overall efficiency, size, and heat dissipation of the power supply. Traditional LLC transformers use a center-tapped structure, which has several drawbacks: On the one hand, center-tapped MOSFETs require two sets of coils to operate, which are complex to wind and have high impedance, resulting in significant copper losses. On the other hand, the rectifier MOSFETs corresponding to center-tapped structures need to withstand a high voltage of 150V. These high-voltage MOSFETs are not only expensive but also have a large on-resistance (Rdson). Furthermore, there is a lack of compatible surface-mount products on the market. Even if a small number of surface-mount high-voltage MOSFETs exist, their excessive on-resistance will lead to excessive losses, making them unsuitable for high-power-density power supplies.

[0003] Therefore, there is an urgent need for an LLC transformer that can reduce copper losses and component losses to meet the development needs of high power density power supplies. Utility Model Content

[0004] This specification provides an LLC transformer with reduced copper losses to address the problems existing in the prior art.

[0005] To solve the above-mentioned technical problems, the embodiments in this specification are implemented as follows: This specification provides an LLC transformer for reducing copper losses. The LLC transformer adopts a full-wave rectification structure, which is configured with a set of coils wound on the transformer core skeleton and is adapted to an 80V surface-mount rectifier MOSFET.

[0006] Optionally, the two ends of the coil are electrically connected to the corresponding pins of the surface-mount rectifier MOSFET.

[0007] Optionally, the magnetic core frame is a high-frequency magnetic core frame, and the coil is made of enameled copper wire wound in the winding groove of the magnetic core frame.

[0008] Optionally, the connection between the coil lead and the pin of the surface-mount rectifier MOSFET is covered with an insulating protective layer.

[0009] Optionally, the circuit board of the LLC transformer is provided with a heat dissipation pad, and the surface mount rectifier MOSFET is mounted on the surface of the heat dissipation pad.

[0010] Optionally, the heat dissipation pad is a copper pad, and the surface of the heat dissipation pad is coated with a thermally conductive and insulating coating.

[0011] One embodiment of this specification achieves the following beneficial effects: The embodiments in this specification adopt a full-wave rectification structure, which requires only one set of coils. Furthermore, a transformer of the same specifications can be wound with a coil of double the number of turns, thereby reducing the coil impedance by 1 / 2. According to the copper loss calculation formula I²R, the copper loss can be reduced by 1 / 2, which significantly improves the power transmission efficiency of the LLC transformer.

[0012] The surface-mount rectifier MOSFETs in the embodiments of this specification only require a withstand voltage of 80V. Compared with the 150V required by the center-tapped structure, the 80V MOSFET is cheaper and has lower on-resistance, further reducing component cost and power loss.

[0013] The heat sources of the rectifier MOSFETs in the embodiments of this specification are distributed in a distributed manner, which avoids the problem of a single heat source being concentrated, and can effectively dissipate heat, thereby improving the working stability and service life of the transformer.

[0014] The embodiments in this specification use surface-mount rectifier MOSFETs, which reduces the size of the transformer. Combined with the advantages of reduced copper losses and optimized heat dissipation, the power density of high-power power supplies is effectively improved. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments or prior art of this specification, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A structural diagram of an LLC transformer with a center-tapped structure provided in the embodiments of this specification; Figure 2 This is a structural diagram of an LLC transformer for reducing copper losses, provided as an embodiment of this specification. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of one or more embodiments of this specification clearer, the technical solutions of one or more embodiments of this specification will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this specification, and not all of them. Based on the embodiments in this specification, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of one or more embodiments of this specification.

[0018] As a core component of a power supply, the performance of the LLC transformer directly affects the overall efficiency, size, and heat dissipation of the power supply. Figure 1 This is a structural diagram of an LLC transformer with a center-tapped structure, provided as an embodiment of this specification. Figure 1 As shown, the center tap of this LCC transformer requires two sets of coils to work together. The coil winding is complex and has high impedance, resulting in significant copper losses. Moreover, the rectifier MOSFET corresponding to the center tap structure needs to withstand a high voltage of 150V. Such high-voltage MOSFETs are not only expensive but also have high on-resistance. At the same time, there is a lack of suitable surface-mount products on the market. Even if there are a few surface-mount high-voltage MOSFETs, their excessive on-resistance will lead to excessive losses, making them unsuitable for high-power-density power supplies.

[0019] Figure 2 A structural diagram of an LLC transformer for reducing copper losses, provided as an embodiment of this specification, is shown below. Figure 2 As shown. The LLC transformer with reduced copper loss provided in the embodiments of this specification adopts a full-wave rectification structure. The full-wave rectification structure is equipped with a set of coils wound on the transformer core skeleton and is adapted to an 80V surface-mount rectifier MOSFET.

[0020] In the embodiments of this specification, the full-wave rectifier structure only requires one set of coils. A transformer of the same specifications can be wound with twice the number of turns, that is, the coil impedance can be reduced by 1 / 2. According to the formula I²R, the power loss can be reduced by 1 / 2.

[0021] Regarding the selection of the rectifier MOSFET, the full-wave rectification structure reduces the voltage withstand requirement of the rectifier MOSFET to half that of the center-tapped structure. In this embodiment, an 80V MOSFET is sufficient. This 80V MOSFET is not only significantly cheaper than a 150V MOSFET, but also has a lower on-resistance. For example, the on-resistance of a traditional 150V MOSFET is 50mΩ, while the on-resistance of a similar 80V MOSFET is only 20mΩ, further reducing the MOSFET's conduction losses.

[0022] Furthermore, the 80V MOSFET in the embodiments of this specification is surface mount, and the use of surface mount MOSFETs can effectively reduce the overall size of LLC transformers, which meets the miniaturization design requirements of high power density power supplies.

[0023] Furthermore, in the full-wave rectification structure of the embodiments in this specification, the heat source of the rectifier MOSFET is distributed in a distributed manner, rather than the concentrated heat source form under the non-center tap structure. The heat source is evenly dispersed, and in conjunction with the heat dissipation system of the power supply, the operating temperature of the transformer can be reduced by 10-20°C, which significantly improves the heat dissipation efficiency and operating stability of the equipment.

[0024] In one specific implementation, the two ends of the coil of the full-wave rectifier structure are electrically connected to the corresponding pins of the surface-mount rectifier MOSFET.

[0025] In one specific implementation, the transformer core frame is a high-frequency core frame, and the coil of the full-wave rectifier structure is made of enameled copper wire wound in the winding slot of the core frame.

[0026] In one specific implementation, the connection between the coil lead of the full-wave rectifier structure and the pin of the surface-mount rectifier MOSFET is covered with an insulating protective layer.

[0027] In one specific implementation, the circuit board of the LLC transformer is provided with a heat dissipation pad, and the surface mount rectifier MOSFET is mounted on the surface of the heat dissipation pad.

[0028] In one specific implementation, the heat dissipation pad is a copper pad, and the surface of the heat dissipation pad is coated with a thermally conductive and insulating coating.

[0029] In practical applications, the LLC transformers in the embodiments of this specification can be adapted to high power density power supplies.

[0030] The LLC transformer with reduced copper loss in the embodiments of this specification effectively reduces copper loss and component costs through the design of a full-wave rectifier structure, optimizes heat dissipation and reduces size, and can be mass-produced and applied to the manufacture of high-power power supplies, significantly improving the power density and market competitiveness of power supplies, and has significant industrial applicability.

[0031] It should be understood that the order of some steps in the methods described in one or more embodiments of this specification may be interchanged according to actual needs, or some steps may be omitted or deleted.

[0032] The foregoing has described specific embodiments of this specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired result. In some embodiments, multitasking and parallel processing are possible or may be advantageous.

[0033] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that the embodiments in this specification are not limited to the described order of actions, because according to the embodiments in this specification, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in this specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the embodiments in this specification.

[0034] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0035] The preferred embodiments disclosed above are merely illustrative of this specification. Optional embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the embodiments described herein. These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of the embodiments, thereby enabling those skilled in the art to better understand and utilize this specification. This specification is limited only by the claims and their full scope and equivalents.

Claims

1. An LLC transformer with reduced copper losses, characterized in that, The LLC transformer employs a full-wave rectification structure, which includes a set of coils wound around the transformer core frame and is compatible with an 80V surface-mount rectifier MOSFET. The two ends of the coils are electrically connected to the corresponding pins of the surface-mount rectifier MOSFET. The core frame is a high-frequency core frame, and the coils are wound with enameled copper wire within the winding slots of the core frame. The connection between the coil leads and the pins of the surface-mount rectifier MOSFET is covered with an insulating protective layer. The LLC transformer's circuit board has a heat dissipation pad, and the surface-mount rectifier MOSFET is mounted on the surface of this heat dissipation pad. The heat dissipation pad is made of copper, and its surface is coated with a thermally conductive and insulating coating.

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