Transformer and vehicle-mounted charger

Abstract

The embodiment of the utility model discloses a transformer and a vehicle-mounted charger, and relates to the technical field of transformers. The transformer comprises a magnetic core, a shielding cover, a winding and a base. The winding is wound on the magnetic core to form excitation inductance and leakage inductance; the shielding cover comprises a body part and a bending part, the body part completely covers the winding, the cross section of the bending part is in a V shape, and the bending part extends outwards along the edge of the body part. The base is configured to be connected with the PCB; wherein the shielding cover is located between the winding and the base, so that leakage magnetic flux formed by the winding is prevented from being transferred to the PCB through the base. According to the transformer, the windings are wound on the magnetic core, and the magnetic flux coupling degree between the windings can be controlled by adjusting the arrangement mode of the windings and the structure of the magnetic core, so that the leakage inductance is adjusted to be equivalent to resonant inductance, and additional inductance elements are reduced. Meanwhile, the shielding cover is additionally arranged between the winding and the base of the transformer, leakage magnetic flux can be shielded, and electronic devices on a PCB connected with the base are prevented from being overheated.

Description

Technical Field

[0001] This utility model relates to the field of transformer technology, and in particular to a transformer and an on-board charger. Background Technology

[0002] As countries place increasing demands on environmental protection, the development of new energy vehicles in the automotive industry is also accelerating. With the continuous upgrading and iteration of in-vehicle intelligence, there are more and more in-vehicle electrical devices, and the power consumption of new energy vehicles is also increasing. The capacity and charging technology of high-voltage batteries are becoming more and more widely used in automobiles. Therefore, the importance of on-board chargers in new energy vehicles is also increasing, and the technical requirements are becoming more and more stringent.

[0003] In new energy vehicles, the on-board charger receives its input from the power grid. The AC power input from the grid typically needs to pass through the first-stage rectifier circuit in the charger, where a power factor correction circuit is added to reduce harmonics, before being fed into the second-stage DC-DC converter circuit. This DC-DC converter then charges the vehicle's high-voltage battery. The second-stage high-voltage to high-voltage DC-DC converter in the charger usually employs a high-efficiency LLC resonant converter. Related technologies include... Figure 1 As shown, the LLC resonant converter contains two magnetic components: a resonant inductor and a transformer.

[0004] In current products, optimizing the size of magnetic components to provide power density and reduce costs has become a key issue. Integrating resonant inductors and LLC transformers is a common approach, with leakage inductance integration being a frequently used method. However, leakage inductance integration uses the leakage inductance as the resonant inductance, often requiring a large leakage inductance value to meet circuit requirements. In on-board chargers, LLC transformers are typically encapsulated in a metal cavity with potting compound, and their pins are soldered to a PCB. Excessive leakage inductance causes the leakage flux to diffuse onto the electronic components on the PCB, leading to severe overheating. A solution in related technologies is to increase the distance between the transformer and the PCB, but this requires significant space and results in considerable volume waste. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this utility model is to provide a transformer and an on-board charger. The transformer has windings wound on a magnetic core. By adjusting the arrangement of the windings (such as winding spacing, number of layers, and winding sequence) and the magnetic core structure (such as air gap size), the magnetic flux coupling between the windings can be controlled, thereby adjusting the leakage inductance to be equivalent to a resonant inductor, reducing the need for additional inductor components. Furthermore, a shielding cover is added between the windings and the base to shield the leakage magnetic flux and prevent the electronic components on the PCB connected to the base from overheating.

[0006] This utility model embodiment discloses a transformer, including:

[0007] magnetic core;

[0008] A winding, the winding being wound around the magnetic core, to form magnetizing inductance and leakage inductance;

[0009] The shield includes a body and a bent portion, the body completely covering the winding, the bent portion having a "V" shaped cross-section, and the bent portion extending outward along the edge of the body.

[0010] The base is configured to connect to the PCB board;

[0011] The shield is located between the winding and the base to prevent the leakage flux formed by the winding from being transferred to the PCB board through the base.

[0012] Furthermore, the shielding cover includes a stainless steel shielding cover or a metal cover.

[0013] Furthermore, the side of the bent portion away from the main body is a mounting section, and the mounting section has multiple grooves in its own extending direction, forming a serrated mounting section through the multiple grooves.

[0014] Furthermore, it also includes a frame that covers the magnetic core, and the windings are arranged on the frame to wind the magnetic core.

[0015] Furthermore, the magnetic core includes an EE-type magnetic core, a PQ-type magnetic core, a U-type magnetic core, or a split magnetic core.

[0016] This utility model embodiment also discloses an on-board charger, including:

[0017] As mentioned above, transformers;

[0018] The water-cooled plate shell itself forms a water-cooled cavity;

[0019] The transformer is arranged inside the water-cooled cavity, and the shielding cover abuts against the water-cooled plate shell.

[0020] Furthermore, the water-cooled cavity is filled with potting compound, and the shield is at least partially immersed in the potting compound.

[0021] Furthermore, the transformer is an LLC transformer, an LC transformer, or a CLLLC transformer.

[0022] The transformer provided by this utility model has the following beneficial effects, including but not limited to:

[0023] 1) The transformer winds on a magnetic core. By adjusting the arrangement of the windings (such as winding spacing, number of layers, and winding sequence) and the magnetic core structure (such as air gap size), the magnetic flux coupling between the windings can be controlled, thereby adjusting the leakage inductance to achieve an equivalent resonant inductance and reduce additional inductor components. A shielding cover is then added between the windings and the base to shield the leakage flux and prevent the electronic components on the PCB connected to the base from overheating.

[0024] 2) The bend at the edge of the shielding cover of the vehicle charger is V-shaped, which can abut against the water-cooled plate housing, resulting in good heat dissipation. Since the water-cooled plate is a low-voltage ground, the connection between the metal cover and the low-voltage ground can also improve the electromagnetic compatibility (EMC) of the vehicle charger.

[0025] 3) In this on-board charger, the shielding cover is immersed in potting compound for heat dissipation, and is also pressed into the water-cooled plate housing that contacts the metal, which can also dissipate heat. Moreover, the heat dissipation effect of the metal is much greater than that of the potting compound. At the same time, the bent edge also has a high heat dissipation function. Therefore, their combined use can improve the temperature rise of the transformer. Attached Figure Description

[0026] This specification will be further described by way of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting; in these embodiments, the same reference numerals denote the same structures, wherein:

[0027] Figure 1 Schematic diagram of an LLC resonant converter provided for related technologies;

[0028] Figure 2 A schematic diagram of the transformer provided in an embodiment of this utility model;

[0029] Figure 3 A schematic diagram of the magnetic core provided in an embodiment of this utility model;

[0030] Figure 4 A schematic diagram of the skeleton provided in the embodiment of this utility model;

[0031] Figure 5 An exploded view of the transformer provided for an embodiment of this utility model;

[0032] Figure 6 This is a schematic diagram of the structure of the on-board charger provided in an embodiment of the present utility model;

[0033] Figure 7 A schematic diagram of the structure of the shielding cover provided in the embodiment of this utility model;

[0034] Figure 8 This is a schematic diagram illustrating the fit between the shielding cover and the water-cooled plate housing provided in an embodiment of the present invention.

[0035] Icons: 100-Transformer; 10-Magnetic core; 11-Shielding cover; 111-Body section; 112-Bending section; 1121-Mounting section; 1122-Groove; 12-Winding; 13-Frame; 14-Base; 200-On-board charger; 20-Water-cooled plate housing; 300-PCB. Detailed Implementation

[0036] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0037] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0038] Please refer to Figures 2-8 This utility model provides a transformer 100, which includes a magnetic core 10, a shield 11, a winding 12, and a base 14. The winding 12 is wound around the magnetic core 10 to form magnetizing inductance and leakage inductance; the shield 11 includes a body portion 111 and a bent portion 112, the body portion 111 completely covers the winding 12, the cross-section of the bent portion 112 is "V" shaped, and the bent portion 112 extends outward along the edge of the body portion 111; the base 14 is configured to connect to a PCB board; wherein, the shield 11 is located between the winding 12 and the base 14 to prevent the leakage magnetic flux formed by the winding 12 from being transferred to the PCB board through the base 14.

[0039] It should be understood that the transformer 100 winds 12 on the magnetic core 10. The degree of magnetic flux coupling between the windings 12 can be controlled by adjusting the arrangement of the windings 12 (such as the spacing, number of layers, and winding sequence) and the structure of the magnetic core 10 (such as the air gap size), thereby adjusting the leakage inductance to be equivalent to a resonant inductor and reducing the need for additional inductor components. That is, when the primary winding 12 of the transformer 100 is wound on the magnetic core 10, magnetic flux is generated in the magnetic core 10 after the primary winding 12 is energized. However, due to incomplete coupling between the primary and secondary windings 12, some magnetic flux leaks into the space surrounding the windings 12 and is not transmitted to the secondary winding 12. This uncoupled magnetic flux generates a certain equivalent inductance on both the primary and secondary sides, which is the leakage inductance, and can be used to replace the resonant inductor.

[0040] It is also worth noting that the shield 11 added between the winding 12 and the base 14 of the transformer 100 can shield the leakage flux, preventing the electronic components on the PCB 300 connected to the base 14 from overheating. Specifically, the leakage flux refers to the aforementioned leakage inductance flux. By shielding the leakage flux, the leakage inductance flux can be converted into heat and conducted away by the shield 11, thus preventing the leakage flux from transferring to the electronic components on the PCB 300 and causing overheating.

[0041] Optionally, the shielding cover 11 may include a stainless steel shielding cover or a metal cover.

[0042] Specifically, the shielding cover 11 can be a stainless steel shielding cover, an aluminum shielding cover, or a copper shielding cover. Depending on the specific implementation environment, the shielding cover 11 can also be a shielding cover made of other materials. This embodiment is only an example of a specific type of shielding cover and does not constitute a limitation on its specific type.

[0043] Please refer to this again. Figure 7 The cross-section of the bent portion 112 is V-shaped, and the bent portion 112 extends outward along the edge of the main body portion 111. This means that one end of the bent portion is connected to the main body portion, and the other end is a free end (used to support the water-cooled plate shell in this embodiment). Between these two ends, the bent portion forms an included angle to provide good elastic deformation capability. Depending on the specific implementation environment, the V-shape described in this embodiment can also be a U-shape or other similar structure. This is merely an illustrative example of a specific embodiment and does not constitute a specific limitation.

[0044] It is worth noting that the "V"-shaped structure of the bend 112 can better contact the water-cooled plate shell 20, increase the heat dissipation channel, improve the heat conduction efficiency, prevent local overheating of the winding 12, and improve the long-term stability of the transformer 100.

[0045] Optionally, the side of the bent portion 112 away from the main body portion 111 is the mounting section 1121. The mounting section 1121 has multiple grooves 1122 in its own extending direction, forming a serrated mounting section 1121 through the multiple grooves 1122.

[0046] Specifically, the serrated groove 1122 design of the bend 112 provides better mechanical fixation during installation, preventing the shield 11 from loosening or shifting. This design also reduces stress concentration, avoids material fatigue caused by long-term thermal expansion and contraction, and improves the mechanical life of the transformer 100.

[0047] It should be understood that, such as Figure 8 As shown, in practical applications, the V-angle of the bent edge can be adjusted appropriately according to the distance. Meanwhile, the longest edge can be a non-completely flat structure, with each section having a small groove 1122 in a serrated shape. The bent edge allows the transformer 100 to be well pressed against the side wall of the metal water-cooled plate housing 20 during installation, and the serrations release the pressing stress of each section, resulting in a smoother and more complete contact.

[0048] In this embodiment, a frame 13 is also included, which covers the magnetic core 10, and the winding 12 is arranged on the frame 13 to wind the magnetic core 10.

[0049] It is worth noting that the frame 13 in this embodiment is made of high-temperature resistant plastic. The frame 13 can not only support the winding 12, but also the assembly pressure of the transformer 100. The use of high-temperature resistant plastics, such as LCP (liquid crystal polymer) or PPS (polyphenylene sulfide), provides high rigidity and good creep resistance, ensuring that the frame 13 does not deform under high temperature and high frequency operating conditions for a long time, thereby improving the mechanical reliability of the transformer 100.

[0050] Optionally, the magnetic core 10 includes an EE-type magnetic core 10, a PQ-type magnetic core 10, a U-type magnetic core 10, or a split magnetic core 10.

[0051] Specifically, in one embodiment of this invention, the magnetic core 10 is a U-shaped magnetic core 10, such as... Figure 3 As shown. According to the technical concept of the present invention, the magnetic core 10 is not limited to a specific shape. The above is only an example of the structure of the magnetic core 10 and does not constitute a limitation on its structure.

[0052] This utility model embodiment also discloses an on-board charger 200, comprising:

[0053] As mentioned above, transformer 100;

[0054] The water-cooled plate shell 20 has a water-cooled cavity formed within it;

[0055] The transformer 100 is arranged inside the water-cooled cavity, and the shield 11 abuts against the water-cooled plate shell 20.

[0056] In this embodiment, the water-cooled cavity is filled with potting compound, and the shield 11 is at least partially immersed in the potting compound.

[0057] It is worth noting that in this on-board charger 200, the shielding cover 11 is at least partially immersed in the potting compound for heat dissipation, and is also pressed into contact with the metal water-cooled plate housing 20, which can also dissipate heat. Furthermore, the heat dissipation effect of the metal is far greater than that of the potting compound, and the bent edges also have high heat dissipation capabilities. Therefore, their combined use can improve the temperature rise of the transformer 100. Simultaneously, the shielding cover 11 contacts the water-cooled plate housing 20. Since the water-cooled plate is a low-voltage ground, the connection between the metal cover and the low-voltage ground can also improve the electromagnetic compatibility of the on-board charger 200. In addition, in this embodiment, the shielding cover can be partially or completely immersed in the potting compound.

[0058] In this embodiment, transformer 100 is an LLC transformer 100, an LC transformer 100, or a CLLLC transformer 100.

[0059] It is understood that the transformer 100 in this embodiment can also be a ferrite power transformer 100 suitable for use in other circuits.

[0060] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

[0061] Throughout this description, numerous specific details, such as examples of components and / or methods, are provided to provide a complete understanding of embodiments of the present invention. However, those skilled in the art will recognize that embodiments of the present invention may be practiced without one or more of these specific details or by other devices, systems, components, methods, parts, materials, components, etc. In other instances, well-known structures, materials, or operations have not been specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention.

[0062] Throughout this specification, references to "an embodiment," "an embodiment," or "a specific embodiment" mean that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention, but not necessarily in all embodiments. Therefore, the various representations of the phrases "in one embodiment," "in an embodiment," or "in a specific embodiment" in different places throughout the specification do not necessarily refer to the same embodiment. Furthermore, a particular feature, structure, or characteristic of any specific embodiment of the present invention can be combined with one or more other embodiments in any suitable manner. It should be understood that other variations and modifications of the embodiments of the present invention shown herein may be based on the teachings herein and will be considered part of the spirit and scope of the present invention.

[0063] It should also be understood that one or more of the elements shown in the figures may be implemented in a more separate or more integrated manner, or may even be removed because they are inoperable in certain circumstances or provided because they may be useful for a particular application.

[0064] Furthermore, unless otherwise expressly stated, any arrows in the accompanying drawings should be considered illustrative only and not limiting. Additionally, unless otherwise stated, the term "or" as used herein is generally intended to mean "and / or". Where a term is anticipated to provide a separation or combination capability that is unclear, a combination of components or steps will also be considered as indicated.

[0065] As used herein and throughout the claims below, unless otherwise specified, “a” and “the” include the plural references. Similarly, as used herein and throughout the claims below, unless otherwise specified, “in” means “in” and “on”.

[0066] The above description of the embodiments shown in this utility model (including the content in the abstract of the specification) is not intended to be an exhaustive enumeration or to limit the utility model to the precise forms disclosed herein. Although specific embodiments and examples of the utility model have been described herein for illustrative purposes only, various equivalent modifications are possible within the spirit and scope of the utility model, as will be recognized and understood by those skilled in the art. As indicated, these modifications can be made to the utility model in accordance with the above description of the embodiments of the utility model, and such modifications will be within the spirit and scope of the utility model.

[0067] This document has generally described the systems and methods in detail to aid in understanding the present invention. Furthermore, various specific details have been set forth to provide a general understanding of embodiments of the present invention. However, those skilled in the art will recognize that embodiments of the present invention can be practiced without one or more specific details, or using other devices, systems, accessories, methods, components, materials, parts, etc. In other instances, well-known structures, materials, and / or operations have not been specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention.

Claims

1. A transformer, characterized by The transformer comprises: a magnetic core; a winding wound around the magnetic core to form an excitation inductance and a leakage inductance; a shield cover comprising a body portion and a bent portion, the body portion completely covering the winding, the bent portion having a "V" shaped cross section, and the bent portion extending outward along an edge of the body portion; a base configured to be connected to a PCB; wherein the shield cover is located between the winding and the base to avoid leakage magnetic flux formed by the winding from being transferred to the PCB through the base.

2. The transformer of claim 1, wherein The shield cover comprises a stainless steel shield cover or a metal cover.

3. The transformer of claim 1, wherein, A side of the bent portion away from the body portion is a mounting segment, and a plurality of grooves are formed in the mounting segment in a direction of extension of the mounting segment, so that the mounting segment has a sawtooth shape.

4. The transformer of claim 1, wherein, Further comprising a skeleton, the skeleton covering the magnetic core, and the winding being arranged on the skeleton to wind around the magnetic core.

5. The transformer of claim 1, wherein, The magnetic core comprises an EE type magnetic core, a PQ type magnetic core, a U type magnetic core or a split magnetic core.

6. An on-board charger, characterized by, The transformer comprises: any one of claims 1-5; a water-cooled plate shell having a water-cooled cavity formed therein; wherein the transformer is arranged in the water-cooled cavity, and the shield cover abuts against the water-cooled plate shell.

7. The vehicle-mounted charger of claim 6, wherein, The water-cooled cavity is filled with potting glue, and the shield cover is at least partially immersed in the potting glue.

8. The vehicle-mounted charger of claim 6, wherein, The transformer is an LLC transformer, an LC transformer or a CLLLLC transformer.

Images