CN116206869A

CN116206869A - Planar magnetic device and wiring method

Info

Publication number: CN116206869A
Application number: CN202111456377.4A
Authority: CN
Inventors: 廖胜峰; 任文
Original assignee: Guangzhou Shiyuan Electronics Thecnology Co Ltd
Current assignee: Guangzhou Shiyuan Electronics Thecnology Co Ltd
Priority date: 2021-12-01
Filing date: 2021-12-01
Publication date: 2023-06-02
Also published as: WO2023098594A1

Abstract

The embodiment of the application discloses a planar magnetic device and a wiring method, and belongs to the technical field of electronics. Wherein the planar magnetic device comprises: the side column is provided with a first air gap; a middle column parallel to the side columns and provided with a second air gap; coil windings wound on the center posts and having a small line width near the first air gap or the second air gap and a large line width far from the first air gap and the second air gap. Therefore, the embodiment of the application can solve the problem of large loss of the planar magnetic device in the related technology.

Description

Planar magnetic device and wiring method

Technical Field

The present application relates to the field of electronics, and in particular, to a planar magnetic device and a wiring method.

Background

Today, electronic products in various industries are not separated from the use of switching power supplies. The key device affecting the volume in the switching power supply is a magnetic device, and in order to miniaturize the switching power supply, a planar magnetic device may be used. The height of the core in the planar magnetic device may be limited due to the thin thickness of the planar magnetic device. As shown in fig. 1, an air gap is generally formed on the magnetic core to store larger magnetic flux energy, the main magnetic flux 111 passing through the magnetic core is diffused into the window, the bypass magnetic flux 333 passing through the magnetic columns is diffused into the window, and when the magnetic flux passes through the air gap, part of magnetic force lines are dispersed into the window of the magnetic core, the diffusion magnetic flux 222 cuts a winding coil placed in the window, and alternating current is introduced into the winding coil, so that the alternating current cuts the magnetic force lines of the diffusion magnetic flux 222 to generate loss, and the larger the air gap is, the more the diffusion magnetic flux is, the larger the loss is.

Disclosure of Invention

The embodiment of the application provides a planar magnetic device and a wiring method, which are used for at least solving the technical problem of high loss of the conventional planar magnetic device.

According to an aspect of an embodiment of the present application, there is provided a planar magnetic device including: the side column is provided with a first air gap; a middle column parallel to the side columns and provided with a second air gap; coil windings wound on the center posts and having a small line width near the first air gap or the second air gap and a large line width far from the first air gap and the second air gap.

Optionally, the first line width of the coil winding wound at the first position is smaller than the second line width of the coil winding wound at the second position, wherein the first distance of the first position from the second air gap is smaller than the second distance of the second position from the second air gap.

Alternatively, the linewidth is determined based on a first distance of the coil winding from the first air gap, a second distance of the coil winding from the second air gap, a current flowing through the coil winding, and a loss of the planar magnetic device.

Optionally, in the case that the first distance is smaller than the second distance, the line width is determined based on the first distance, the current and the loss; in the case where the first distance is greater than the second distance, the line width is determined based on the second distance, the current, and the loss.

Optionally, the first air gap and the second air gap are disposed opposite.

According to another aspect of the embodiments of the present application, there is also provided a wiring method, which is applied to any one of the planar magnetic devices described above, the wiring method including: acquiring current flowing through the coil winding and loss of the planar magnetic device; determining line widths of the coil windings at different positions on the center post based on the current and the loss; the coil windings are wound around the center posts with line widths at different locations.

Optionally, determining the winding manner of the coil winding on the center post based on the current and the loss includes: determining a plurality of positions at which the coil windings are wound on the center post; determining a first distance of each location from the first air gap and a second distance of each location from the second air gap; and solving an objective function based on the first distance or the second distance, the current and the loss to obtain a winding mode.

Optionally, the wiring method further includes: obtaining the product of the resistivity of the coil winding, the square of the current and the skin effect coefficient to obtain a first product, and obtaining the ratio of the first product to the line width to obtain a skin effect loss function; obtaining a product of line width, resistivity, turns of a coil winding, current square and proximity effect coefficient to obtain a second product, and obtaining a ratio of the second product to the first distance or the square of the second distance to obtain a proximity effect loss function; and obtaining a weighted sum of the skin effect loss function and the proximity effect loss function to obtain an objective function.

According to another aspect of the embodiments of the present application, there is also provided a wiring device applied to any one of the planar magnetic devices described above, the device including: the acquisition module is used for acquiring the current flowing through the coil winding and the loss of the planar magnetic device; the determining module is used for determining the line widths of the coil windings at different positions on the center post based on the current and the loss; and the winding module is used for winding the coil windings on the center posts according to line widths of different positions.

According to another aspect of the embodiments of the present application, there is also provided a readable storage medium storing a plurality of instructions adapted to be loaded by a processor and to perform the steps of the routing method of any one of the above.

According to another aspect of the embodiments of the present application, there is also provided an electronic device, including: a processor and a memory; wherein the memory stores a computer program adapted to be loaded by the processor and to perform any of the wiring method steps described above.

In an embodiment of the present application, there is provided a planar magnetic device including: the side column is provided with a first air gap; a middle column parallel to the side columns and provided with a second air gap; coil windings wound on the center posts and having a small line width near the first air gap or the second air gap and a large line width far from the first air gap and the second air gap. It should be noted that the windings close to the air gap can properly reduce the line width, while the windings far away from the air gap can properly increase the line width, so as to achieve the technical effect of effectively reducing the total alternating current loss, and further solve the technical problem of high loss of the conventional planar magnetic device.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application and do not constitute an undue limitation to the application. In the drawings:

fig. 1 is a schematic view of a magnetomotive force according to the prior art;

FIG. 2 is a schematic diagram of a planar magnetic device according to one prior art;

FIG. 3 is a schematic diagram of a planar magnetic device according to an embodiment of the present application;

FIG. 4 is a schematic diagram of an AC resistance versus curve for a planar magnetic device and a conventional planar magnetic device provided in accordance with an embodiment of the present application;

FIG. 5 is a flow chart of an alternative routing method according to an embodiment of the present application;

FIG. 6 is a schematic diagram of an alternative wiring device according to an embodiment of the present application;

fig. 7 is a schematic diagram of an alternative electronic device according to an embodiment of the present application.

Detailed Description

In order to make the present application solution better understood by those skilled in the art, the following description will be made in detail and with reference to the accompanying drawings in the embodiments of the present application, it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments herein without making any inventive effort, shall fall within the scope of the present application.

When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The implementations described in the following exemplary examples are not representative of all implementations consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with some aspects of the present application as detailed in the accompanying claims.

It should be noted that the terms "first," "second," and the like in the description and claims of the present application and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that embodiments of the present application described herein may be implemented in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus. Furthermore, in the description of the present application, unless otherwise indicated, "a plurality" means two or more. "and/or", describes an association relationship of an association object, and indicates that there may be three relationships, for example, a and/or B, and may indicate: a exists alone, A and B exist together, and B exists alone. The character "/" generally indicates that the context-dependent object is an "or" relationship.

In order to reduce the influence of the diffusion magnetic flux on the coil winding, as shown in fig. 2, one of the conventional planar magnetic devices is that the center pillar 201 and the side pillar 202 are respectively provided with an air gap, which is a center pillar air gap 2011, a side pillar air gap 2021, and the coil winding 203 is wound on the center pillar 201, wherein the height of the air gap can be halved to effectively reduce the influence of the diffusion magnetic flux.

However, the planar magnetic device described above has the following drawbacks: 1. although the length of the air gap is half of the original length, the diffusion magnetic flux is not only diffused through the middle column air gap, but also diffused through the side column air gap, the contact area of the coil winding and the diffusion magnetic flux is increased, the influence range of the coil winding by the diffusion magnetic flux is enlarged, and the problem of high loss is caused; 2. eddy current losses due to the diffuse magnetic flux cutting coil winding area are not considered.

Example 1

An embodiment of the present application provides a planar magnetic device, as shown in fig. 3, including: a side column 301, wherein a first air gap 3011 is arranged on the side column; a middle column 302, parallel to the side column 301, wherein a second air gap 3021 is arranged on the middle column 302; coil windings 303 are wound around the center post 302, and the line widths of the coil windings near the first air gap or the second air gap are small, and the line widths of the coil windings far from the first air gap and the second air gap are large.

It should be noted that, fig. 3 shows a longitudinal section of a right side portion of the planar magnetic device, and a stereoscopic planar magnetic device can be obtained by rotating the right side portion of the planar magnetic device around a vertical direction of a leftmost side in the drawing, as shown in fig. 3, a center pillar may be located at a center position of the planar magnetic device, side pillars may be located around the center pillar, a coil winding is wound around the center pillar, and a wire is isolated from a wire by an insulating material.

The side posts, the middle posts and the coil windings in the steps can be existing side posts, middle posts and coil windings, and the line widths of the windings in the steps can be different, for example, the line widths of the windings close to the air gaps (the first air gap or the second air gap) can be properly reduced, the line widths of the windings far away from the air gaps (the first air gap and the second air gap) can be properly increased, and the total alternating current loss can be effectively reduced by setting different line widths.

Optionally, the first air gap and the second air gap are disposed opposite.

In an alternative embodiment, the coil closer to the air gap would have more magnetic lines of force cutting the coil body according to the law of electromagnetic induction if the coil were wider, resulting in more eddy currents and thus increased losses in the coil. The coil far away from the air gap is weakly cut by the magnetic force lines, so that the line width of the coil is properly increased, and the direct current loss and the skin loss in the alternating current loss of the part can be effectively reduced. Thus, the overall ac losses can be minimized.

In an alternative embodiment, the line width of the coil winding may be determined by a first distance between the location of the coil winding and the first air gap of the leg, a second distance between the location of the coil winding and the second air gap of the center leg, the current flowing through the coil winding, and the loss of the planar magnetic device.

In an alternative embodiment, a first distance between the location of the coil winding and the first air gap of the leg is compared to a second distance between the location of the coil winding and the second air gap of the center leg, and when the first distance is less than the second distance, the line width may be determined based on the first distance, the current, and the loss; when the first distance is greater than the second distance, the line width may be determined based on the second distance, the current, and the loss.

In an alternative embodiment, assume that the current through the coil winding is I _p The line width of the coil winding is W _p According to the Maxwell equation set, the AC loss generated by the skin effect of the coil winding is shown in a formula 2-1, the AC loss generated by the proximity effect is shown in a formula 2-2, and the formula is as follows:

wherein W is _p The line width of the coil winding; ρ is the resistivity of the copper wire; l (L) _p M is the distance of the winding from the air gap (including the first air gap and the second air gap) _p Is the number of turns of the coil winding. K (K) _s1 And K _s2 The parameters are skin effect coefficient and proximity effect coefficient, the parameters are related to parameters such as magnetic permeability, working frequency and the like, and if the magnetic core is fixed, the working frequency is fixed, and the value is a fixed value.

It can be seen from equations 2-1 to 2-2 that for AC losses, the composition of skin effect losses and proximity effect losses, in which the influence of the winding coil far from the air gap is superimposed on the winding coil near the air gap, has a larger influence on the winding coil nearest to the air gap because of l _p Will be relatively small and the losses in this part will be a large proportion of the total losses. Thus, the line width of each layer plays a great role, and for the coil winding close to the first air gap, the total alternating current loss of the coil winding is P1 _ac Because of the distance l of the coil winding from the first air gap of the core leg _p Smaller, so that the loss ratio due to proximity effect is larger, and the line width W of the coil winding is properly reduced _p The total alternating current loss can be effectively reduced; for a coil winding close to the second air gap, the total AC loss of the coil winding is P2 _ac Because of the distance l of the coil winding from the second air gap of the core leg _p Smaller, so that the loss ratio due to proximity effect is larger, and the coil winding width W is properly reduced _p The total alternating current loss can be effectively reduced; for coil windings that are not close to the first and second air gaps, the coil windings have relatively large distances to the first and second air gaps, and therefore, the loss due to the proximity effect is relatively small, and thus, the line width W of the coil windings is properly increased _p The total alternating current loss can be effectively reduced.

By setting the widths of the coil windings at distances from the first air gap and the second air gap, a measurable amount of loss is achieved while ensuring that the smaller the line width of the coil windings is, the more distant the coil windings are from the first air gap or the second air gap.

As shown in fig. 4, comparing the AC resistance of the conventional scheme and the double-sided asymmetric scheme (i.e., the planar magnetic device provided in the present application), the AC resistance of the double-sided asymmetric winding is much smaller than that of the conventional scheme, especially in the high frequency part, and the AC resistance of the double-sided asymmetric winding is much smaller than that of the conventional scheme. In fig. 4, the abscissa indicates frequency (in Hz) and the ordinate indicates AC resistance (in mohm). The correctness of the theoretical analysis is verified through the graph.

In an embodiment of the present application, there is provided a planar magnetic device including: the side column is provided with a first air gap; a middle column parallel to the side columns and provided with a second air gap; coil windings wound on the center posts and having a small line width near the first air gap or the second air gap and a large line width far from the first air gap and the second air gap. It should be noted that the center pillar and the side pillars of the planar magnetic device are provided with air gaps, and the distance from the air gaps is different, and the line widths of the coil windings are different, so that the contact area between the coil windings and the diffusion magnetic flux is reduced, the technical effect of effectively reducing the total alternating current loss is achieved, and the technical problem of high loss of the planar magnetic device in the related art is solved.

Example 2

According to another aspect of the embodiments of the present application, a wiring method is further provided, which is applied to the planar magnetic device summarized in the foregoing embodiment 1, and preferred embodiments and scenarios are described in the foregoing embodiments, and are not repeated herein. As shown in fig. 5, the wiring method includes:

step S502, obtaining current flowing through a coil winding and loss of a planar magnetic device;

the current in the above step is the current flowing through the coil winding.

Step S504, determining line widths of the coil windings at different positions on the center post based on the current and the loss;

and step S506, winding the coil windings on the center posts according to line widths of different positions.

The objective function of the above steps is described in the above embodiments, and will not be described herein.

Example 3

According to another aspect of the embodiments of the present application, there is also provided a wiring device applied to any one of the planar magnetic devices described above, as shown in fig. 6, the device including: an acquisition module 62 for acquiring the current flowing through the coil winding and the loss of the planar magnetic device; a determining module 64 for determining line widths of the coil windings at different positions on the center post based on the current and the loss; and a winding module 66 for winding the coil winding around the center post according to line widths of different positions.

Example 4

The embodiment of the present application further provides a readable storage medium, where the readable storage medium may store a plurality of instructions, where the instructions are adapted to be loaded by a processor and executed by a processor, where the specific execution process may refer to the specific description of the embodiment shown in fig. 5, and details are not repeated herein.

The device on which the readable storage medium resides may be an electronic device.

Example 5

The embodiment of the application further provides an electronic device, as shown in fig. 7, an electronic device 1000 may include: at least one processor 1001, at least one network interface 1004, a user interface 1003, a memory 1005, at least one communication bus 1002.

Wherein the communication bus 1002 is used to enable connected communication between these components.

The user interface 1003 may include a Display screen (Display) and a Camera (Camera), and the optional user interface 1003 may further include a standard wired interface and a wireless interface.

The network interface 1004 may optionally include a standard wired interface, a wireless interface (e.g., WI-FI interface), among others.

Wherein the processor 1001 may include one or more processing cores. The processor 1001 connects various parts within the overall electronic device 1000 using various interfaces and lines, performs various functions of the electronic device 1000 and processes data by executing or executing instructions, programs, code sets, or instruction sets stored in the memory 1005, and invoking data stored in the memory 1005. Alternatively, the processor 1001 may be implemented in at least one hardware form of digital signal processing (Digital Signal Processing, DSP), field programmable gate array (Field-Programmable Gate Array, FPGA), programmable logic array (Programmable Logic Array, PLA). The processor 1001 may integrate one or a combination of several of a central processing unit (Central Processing Unit, CPU), an image processor (Graphics Processing Unit, GPU), and a modem, etc. The CPU mainly processes an operating system, a user interface, an application program and the like; the GPU is used for rendering and drawing the content required to be displayed by the display screen; the modem is used to handle wireless communications. It will be appreciated that the modem may not be integrated into the processor 1001 and may be implemented by a single chip.

The Memory 1005 may include a random access Memory (Random Access Memory, RAM) or a Read-Only Memory (Read-Only Memory). Optionally, the memory 1005 includes a non-transitory computer readable medium (non-transitory computer-readable storage medium). The memory 1005 may be used to store instructions, programs, code, sets of codes, or sets of instructions. The memory 1005 may include a stored program area and a stored data area, wherein the stored program area may store instructions for implementing an operating system, instructions for at least one function (such as a touch function, a sound playing function, an image playing function, etc.), instructions for implementing the above-described respective method embodiments, etc.; the storage data area may store data or the like referred to in the above respective method embodiments. The memory 1005 may also optionally be at least one storage device located remotely from the processor 1001. As shown in fig. 7, an operating system, a network communication module, a user interface module, and an operating application of the electronic device may be included in a memory 1005, which is one type of computer storage medium.

In the electronic device 1000 shown in fig. 7, the user interface 1003 is mainly used for providing an input interface for a user, and acquiring data input by the user; and the processor 1001 may be configured to invoke an operating application of the electronic device stored in the memory 1005, and specifically perform the following operations: acquiring current flowing through the coil winding and loss of the planar magnetic device; determining line widths of the coil windings at different positions on the center post based on the current and the loss; winding coil windings around the center posts according to line widths at different positions

In one embodiment, the operating system of the electronic device is an android system in which the processor 1001 further performs the steps of: based on the current and the loss, determining the winding manner of the coil winding on the center post includes: determining a plurality of positions at which the coil windings are wound on the center post; determining a target distance of each location from the second air gap; and solving an objective function based on the target distance, the current and the loss to obtain a winding mode.

In one embodiment, the processor 1001 further performs the steps of: obtaining the product of the resistivity of the coil winding, the square of the current and the skin effect coefficient to obtain a first product, and obtaining the ratio of the first product to the line width to obtain a skin effect loss function; obtaining a product of line width, resistivity, turns of a coil winding, current square and proximity effect coefficient to obtain a second product, and obtaining a ratio of the second product to the square of a target distance to obtain a proximity effect loss function; and obtaining a weighted sum of the skin effect loss function and the proximity effect loss function to obtain an objective function.

It will be appreciated by those skilled in the art that embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

In one typical configuration, a computing device includes one or more processors (CPUs), input/output interfaces, network interfaces, and memory.

The memory may include volatile memory in a computer-readable medium, random Access Memory (RAM) and/or nonvolatile memory, etc., such as Read Only Memory (ROM) or flash RAM. Memory is an example of a computer-readable medium.

Computer readable media, including both non-transitory and non-transitory, removable and non-removable media, may implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of storage media for a computer include, but are not limited to, phase change memory (PRAM), static Random Access Memory (SRAM), dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), read Only Memory (ROM), electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission medium, which can be used to store information that can be accessed by a computing device. Computer-readable media, as defined herein, does not include transitory computer-readable media (transmission media), such as modulated data signals and carrier waves.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article or apparatus that comprises an element.

The foregoing is merely exemplary of the present application and is not intended to limit the present application. Various modifications and changes may be made to the present application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc. which are within the spirit and principles of the present application are intended to be included within the scope of the claims of the present application.

Claims

1. A planar magnetic device, comprising:

the side column is provided with a first air gap;

the middle column is parallel to the side columns, and a second air gap is arranged on the middle column;

and a coil winding wound on the center post, wherein a line width of the coil winding close to the first air gap or the second air gap is small, and a line width of the coil winding far away from the first air gap and the second air gap is large.

2. The planar magnetic device of claim 1, wherein the linewidth is determined based on a first distance of the coil winding from the first air gap, a second distance of the coil winding from the second air gap, a current flowing through the coil winding, and a loss of the planar magnetic device.

3. The planar magnetic device as claimed in claim 2, wherein,

in the case where the first distance is less than the second distance, the line width is determined based on the first distance, the current, and the loss;

in the case where the first distance is greater than the second distance, the line width is determined based on the second distance, the current, and the loss.

4. The planar magnetic device of claim 1, wherein the first air gap and the second air gap are disposed opposite.

5. A wiring method, characterized by being applied to the planar magnetic device of any one of claims 1 to 4, comprising:

acquiring current flowing through the coil winding and loss of the planar magnetic device;

determining line widths of the coil windings at different positions on the center post based on the current and the loss;

and winding the coil winding on the center post according to the line widths of the different positions.

6. The method of claim 5, wherein determining a winding manner of the coil winding on the center post based on the current and the loss comprises:

determining a plurality of positions at which the coil windings are wound on the center post;

determining a first distance of each location from a first air gap and a second distance of each location from the second air gap;

and solving an objective function based on the first distance or the second distance, the current and the loss to obtain the winding mode.

7. The method of claim 6, wherein the method further comprises:

obtaining the product of the resistivity of the coil winding, the square of the current and the skin effect coefficient to obtain a first product, and obtaining the ratio of the first product to the line width to obtain the skin effect loss function;

obtaining a product of the line width, the resistivity, the number of turns of the coil winding, the square of the current and a proximity effect coefficient to obtain a second product, and obtaining a ratio of the second product to the first distance or the square of the second distance to obtain the proximity effect loss function;

and obtaining a weighted sum of the skin effect loss function and the proximity effect loss function to obtain the objective function.

8. A wiring device, characterized in that it is applied to the planar magnetic device according to any one of claims 1 to 4, the device comprising:

the acquisition module is used for acquiring the current flowing through the coil winding and the loss of the planar magnetic device;

a determining module for determining line widths of the coil windings at different positions on the center post based on the current and the loss;

and the winding module is used for winding the coil winding on the center post according to the line widths of the different positions.

9. A readable storage medium, characterized in that it stores a plurality of instructions adapted to be loaded by a processor and to perform the method steps of any of claims 5 to 7.

10. An electronic device, comprising: a processor and a memory; wherein the memory stores a computer program adapted to be loaded by the processor and to perform the method steps of any of claims 5 to 7.