Magnetic coupling system for wireless charging system and method for optimizing structural parameters thereof

Abstract

The present application relates to the technical fields of wireless power transmission, and especially relates to a magnetic coupling system for a wireless charging system and a structural parameter optimization method thereof, wherein the magnetic coupling system comprises: a primary magnetic coupling mechanism and a secondary magnetic coupling mechanism, and the primary magnetic coupling mechanism and the secondary magnetic coupling mechanism can generate a magnetic coupling effect; the primary magnetic coupling mechanism comprises: a first magnetic coupling mechanism and a second magnetic coupling mechanism; the secondary magnetic coupling mechanism comprises: a third magnetic coupling mechanism and a fourth magnetic coupling mechanism; the first magnetic coupling mechanism and the second magnetic coupling mechanism are arranged in the same plane, and there is a first air gap between the first magnetic coupling mechanism and the second magnetic coupling mechanism, and the first magnetic coupling mechanism and the second magnetic coupling mechanism are connected in series through winding; the third magnetic coupling mechanism and the fourth magnetic coupling mechanism are arranged in the same plane, and there is a second air gap between the third magnetic coupling mechanism and the fourth magnetic coupling mechanism, and the third magnetic coupling mechanism and the fourth magnetic coupling mechanism are connected in series through winding. The present application can effectively reduce the weight of the magnetic coupling system, reduce the amount of winding used, and ensure strong anti-offset performance.

Description

Technical Field

[0001] This invention relates to the field of wireless power transmission technology, and in particular to a magnetic coupling system for wireless charging systems and a method for optimizing its structural parameters. Background Technology

[0002] Wireless power transfer (WPT) technology can transmit electrical energy without the need for physical media such as cables. Therefore, compared with traditional wired power transmission methods, it has advantages such as electrical isolation, convenience, and safety, and can effectively solve the various problems associated with wired power transmission. Among various wireless power transfer technologies, electromagnetic induction wireless power transfer technology is currently widely used due to its lower cost and less power loss.

[0003] See Figure 1 , Figure 1 This is a schematic diagram of an existing electromagnetic induction-based wireless power transfer system. Figure 1 The circuit is divided into two parts: the primary circuit and the secondary circuit, which are physically isolated. In the primary circuit, the input DC power is converted into high-frequency AC power by a high-frequency inverter, and then fed to the primary magnetic coupling mechanism of the loosely coupled transformer after primary compensation. In the secondary circuit, the secondary magnetic coupling mechanism of the loosely coupled transformer induces an electromotive force, which is then compensated on the secondary side. The compensated voltage is then converted into DC power by a rectifier circuit and the subsequent DC / DC module.

[0004] See Figure 2 , Figure 2 This is a schematic diagram of an existing magnetic coupling system. In the primary and secondary magnetic coupling mechanism, the primary and secondary windings are wound on the primary and secondary magnetic cores, respectively, and separated by a layer of acrylic material. (See also...) Figure 3 , Figure 3 This is a schematic diagram of wireless charging for electric vehicles. The shaded area on the primary side represents the primary magnetic coupling mechanism, and the shaded area on the secondary side represents the secondary magnetic coupling mechanism. To ensure high power transmission efficiency in the wireless charging system, the primary and secondary magnetic coupling mechanisms are typically required to be directly opposite each other during charging. However, in practical applications, due to factors such as differences in driver skill, the relative positions of the primary and secondary magnetic coupling mechanisms often shift. This shift causes changes in the coupling coefficient between the primary and secondary magnetic coupling mechanisms, resulting in variations in output voltage, current, and efficiency. In the closed-loop design of the DC / DC module introduced after the WPT system, such drastic changes in the coupling coefficient significantly increase the design complexity of the DC / DC module, potentially leading to a very large physical size and high design cost.

[0005] However, the existing loosely coupled transformers have problems with their primary and secondary magnetic coupling mechanisms, such as large weight, extensive use of Litz wire, and weak resistance to displacement. Summary of the Invention

[0006] Based on the above analysis, the present invention aims to provide a magnetic coupling system for wireless charging systems and a method for optimizing its structural parameters, in order to solve the technical problems of large weight of primary and secondary side magnetic coupling mechanisms, large use of Litz wires, and weak anti-offset capability in the prior art.

[0007] The technical solution provided by this invention is:

[0008] On one hand, embodiments of the present invention provide a magnetic coupling system for a wireless charging system, comprising: a primary-side magnetic coupling mechanism and a secondary-side magnetic coupling mechanism, wherein the primary-side magnetic coupling mechanism and the secondary-side magnetic coupling mechanism are capable of generating a magnetic coupling effect;

[0009] The primary-side magnetic coupling mechanism includes: a first magnetic coupling mechanism and a second magnetic coupling mechanism;

[0010] The secondary magnetic coupling mechanism includes: a third magnetic coupling mechanism and a fourth magnetic coupling mechanism;

[0011] The first magnetic coupling mechanism and the second magnetic coupling mechanism are arranged in the same plane and have a first air gap, and are connected in series by a winding.

[0012] The third magnetic coupling mechanism and the fourth magnetic coupling mechanism are arranged in the same plane and have a second air gap, and are connected in series by winding.

[0013] Preferably, the first magnetic coupling mechanism includes: a first coil and a first magnetic core;

[0014] The second magnetic coupling mechanism includes: a second coil and a second magnetic core;

[0015] The third magnetic coupling mechanism includes: a third coil and a third magnetic core;

[0016] The fourth magnetic coupling mechanism includes: a fourth coil and a fourth magnetic core;

[0017] All four magnetic cores are flat, and the first magnetic core and the second magnetic core have the same specifications, and the third magnetic core and the fourth magnetic core have the same specifications;

[0018] The first coil is isolated from the first magnetic core by an insulating layer and is wound on the first magnetic core in a predetermined direction;

[0019] The second coil is isolated from the second magnetic core by an insulating layer and is wound on the second magnetic core in the predetermined direction;

[0020] The third coil is isolated from the third magnetic core by an insulating layer and is wound on the third magnetic core in the preset specified direction;

[0021] The fourth coil is isolated from the fourth magnetic core by an insulating layer and is wound on the fourth magnetic core in the preset specified direction.

[0022] Preferably, the first coil and the second coil are wound with single-strand wire and connected in series; the third coil and the fourth coil are wound with single-strand wire and connected in series; or,

[0023] The first coil and the second coil are wound with double-strand wire and connected in series; the third coil and the fourth coil are wound with double-strand wire and connected in series.

[0024] Preferably, the first magnetic coupling mechanism and the second magnetic coupling mechanism are mirror images of each other;

[0025] The third magnetic coupling mechanism is mirror-symmetric to the fourth magnetic coupling mechanism.

[0026] On the other hand, embodiments of the present invention also provide a method for optimizing the structural parameters of a magnetic coupling system for a wireless charging system, used to design the structural parameters of the magnetic coupling system for the wireless charging system, the structural parameters including: a first type of structural parameters and a second type of structural parameters, the method including:

[0027] Predetermine a first type of structural parameters that do not require debugging and a second type of structural parameters that require debugging. The second type of structural parameters includes a first spacing value and a second spacing value. The first spacing value is the size of the first air gap between the first magnetic coupling mechanism and the second magnetic coupling mechanism in the primary side magnetic coupling mechanism. The second spacing value is the size of the second air gap between the third magnetic coupling mechanism and the fourth magnetic coupling mechanism in the secondary side magnetic coupling mechanism.

[0028] Pre-select coupling performance parameters that are related to the anti-offset performance of the magnetic coupling system;

[0029] By using the control variable method and combining the coupling performance parameters, the second type of structural parameters are adjusted to obtain the optimized results of the second type of structural parameters.

[0030] Preferably, the first type of structural parameters includes: the first total length of the primary side magnetic coupling mechanism in a preset specified direction, and the second total length of the secondary side coupling mechanism in the specified direction;

[0031] The coupling performance parameters include: the coupling coefficient of the magnetic coupling system after it is offset in the specified direction, and the rate of change of the coupling coefficient corresponding to the coupling coefficient, which reflects the anti-offset performance of the magnetic coupling system in the specified direction.

[0032] Preferably, a first empirical low threshold for the coupling coefficient and a second empirical low threshold for the rate of change of the coupling coefficient are preset;

[0033] The step of using the control variable method, combined with the coupling performance parameters, to adjust the second type of structural parameters and obtain the optimization results of the second type of structural parameters includes:

[0034] It is determined that the first spacing value and the first type of structural parameter value remain unchanged;

[0035] By changing the offset of the magnetic coupling system in the specified direction and the second spacing value, the corresponding coupling coefficient and the rate of change of the coupling coefficient are obtained;

[0036] The second spacing value is selected when the obtained coupling coefficient and the rate of change of the coupling coefficient satisfy the preset selection conditions. The selection conditions include: the coupling coefficient is greater than the first empirical low threshold and the rate of change of the coupling coefficient is greater than the second empirical low threshold.

[0037] The optimization result is determined by comparing the first spacing value with the optimized second spacing value; or,

[0038] The second spacing value is determined to remain unchanged from the first type of structural parameter value;

[0039] By changing the offset of the magnetic coupling system in the specified direction and the first spacing value, the corresponding coupling coefficient and the rate of change of the coupling coefficient are obtained;

[0040] The first spacing value is selected when the obtained coupling coefficient and the rate of change of the coupling coefficient satisfy the preset selection conditions.

[0041] The optimization result is determined by comparing the second spacing value with the optimized first spacing value.

[0042] Preferably, the structural parameter optimization method further includes:

[0043] Pre-select material usage parameters that reflect the material usage of the magnetic coupling system;

[0044] The coupling material usage parameters corresponding to the selected optimized second spacing value meet the preset requirements; or,

[0045] The coupling material usage parameters corresponding to the selected optimized first spacing value meet the preset requirements.

[0046] Preferably, the parameters for the amount of coupling material include: the volume of the coupling material and the normalized inductance coefficient;

[0047] The normalized inductance coefficient includes:

[0048]

[0049] Among them, A Tx L represents the normalized inductance coefficient of the primary-side magnetic coupling mechanism. Tx The value of self-inductance of the primary-side magnetic coupling mechanism is represented by l. LitzTx A represents the total winding length of the primary-side magnetic coupling mechanism; Rx L represents the normalized inductance coefficient of the secondary magnetic coupling mechanism. Rx The value of the self-inductance of the secondary magnetic coupling mechanism is represented by l. LitzRx This indicates the total winding length of the secondary magnetic coupling mechanism.

[0050] Preferably,

[0051]

[0052] Among them, l STx For the first spacing value, l Tx The first total length; l SRx The second spacing value, l Rx This is the second total length.

[0053] In the technical solutions provided by the embodiments of the present invention, the inventors have... Figure 2 The loosely coupled transformer structure shown is to be improved by considering removing... Figure 2 The magnetic core in the middle part of the primary and secondary magnetic coupling mechanism shown can ensure anti-displacement performance while occupying the same space volume, effectively reduce the weight of the magnetic coupling system itself, and reduce the amount of winding, thereby effectively reducing costs. It also helps to reduce the design difficulty of DC / DC modules and helps to promote the industrialization of wireless charging.

[0054] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0055] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0056] Figure 1 This is a schematic diagram of an existing electromagnetic induction-based wireless power transfer system.

[0057] Figure 2 This is a schematic diagram of an existing magnetic coupling system;

[0058] Figure 3 This is a schematic diagram of wireless charging for electric vehicles.

[0059] Figure 4 This is a schematic diagram of the magnetic coupling system structure used in the wireless charging system in an embodiment of the present invention;

[0060] Figure 5 This is a specific structural example diagram of the magnetic coupling system in an embodiment of the present invention;

[0061] Figure 6 This is a first winding example diagram of the primary and secondary side magnetic coupling mechanism in this embodiment of the invention;

[0062] Figure 7 This is a second winding example diagram of the primary and secondary side magnetic coupling mechanism in this embodiment of the invention;

[0063] Figure 8 This is an embodiment of the present invention. Figure 7 The front view of the magnetic coupling system shown;

[0064] Figure 9 This is an embodiment of the present invention. Figure 7 Side view of the magnetic coupling system shown;

[0065] Figure 10 This is a flowchart of the structural parameter optimization method for a magnetic coupling system used in a wireless charging system according to an embodiment of the present invention;

[0066] Figure 11 This is a first example diagram showing the result of debugging the second type of structural parameters based on the control variable method in an embodiment of the present invention;

[0067] Figure 12 This is a second example diagram showing the result of debugging the second type of structural parameters based on the control variable method in an embodiment of the present invention;

[0068] Figure 13 This is a third example diagram showing the result of debugging the second type of structural parameters based on the control variable method in an embodiment of the present invention;

[0069] Figure 14 This is an example diagram of the effective magnetic region when the magnetic coupling system is facing each other in an embodiment of the present invention;

[0070] Figure 15 This is an example diagram of the effective magnetic region of the magnetic coupling system in an embodiment of the present invention when the magnetic coupling system is offset by 100mm in the X direction;

[0071] Figure 16 This is an example diagram of the effective magnetic region of the magnetic coupling system in an embodiment of the present invention when the magnetic coupling system is offset by 200mm in the X direction;

[0072] Figure 17 This is an example diagram of the effective magnetic region of the magnetic coupling system in an embodiment of the present invention when the magnetic coupling system is offset by 300 mm in the X direction;

[0073] Figure 18 This is an example diagram of the effective magnetic region of the magnetic coupling system in an embodiment of the present invention when the magnetic coupling system is offset by 400mm in the X direction. Detailed Implementation

[0074] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and, together with the embodiments of the present invention, serve to illustrate the principles of the present invention.

[0075] This invention provides a magnetic coupling system for a wireless charging system, see [link to relevant documentation]. Figure 4 , Figure 4 This is a schematic diagram of the magnetic coupling system structure used in the wireless charging system in an embodiment of the present invention. Figure 4 The magnetic coupling system 400 shown may include: a primary magnetic coupling mechanism 401 and a secondary magnetic coupling mechanism 402, and a magnetic coupling effect can be generated between the primary magnetic coupling mechanism 401 and the secondary magnetic coupling mechanism 402.

[0076] The primary magnetic coupling mechanism 401 may include: a first magnetic coupling mechanism 4011 and a second magnetic coupling mechanism 4012;

[0077] The secondary magnetic coupling mechanism 402 may include: a third magnetic coupling mechanism 4021 and a fourth magnetic coupling mechanism 4022;

[0078] The first magnetic coupling mechanism 4011 and the second magnetic coupling mechanism 4012 are arranged in the same plane and have a first air gap, and are connected in series by winding.

[0079] The third magnetic coupling mechanism 4021 and the fourth magnetic coupling mechanism 4022 are arranged in the same plane and have a second air gap, and are connected in series by winding.

[0080] In this embodiment of the invention, the inventors... Figure 2 The loosely coupled transformer structure shown is to be improved by considering removing... Figure 2 The magnetic core in the middle part of the primary and secondary magnetic coupling mechanism shown can ensure anti-offset performance while occupying the same space volume, effectively reduce the weight of the magnetic coupling system itself, and reduce the amount of winding, thereby effectively reducing costs. It also helps to reduce the design difficulty of DC / DC modules and promotes the industrialization of wireless charging.

[0081] See Figure 5 , Figure 5 This is a specific structural example diagram of the magnetic coupling system in an embodiment of the present invention. Figure 5 In the process, the primary magnetic coupling mechanism serves as the power transmitting end, wherein the first magnetic coupling mechanism 4011 may include: a first coil W1 and a first magnetic core F1; the second magnetic coupling mechanism 4012 may include: a second coil W2 and a second magnetic core F2; the secondary magnetic coupling mechanism serves as the power receiving end, wherein the third magnetic coupling mechanism 4021 includes: a third coil W3 and a third magnetic core F3; and the fourth magnetic coupling mechanism 4022 includes: a fourth coil W4 and a fourth magnetic core F4.

[0082] All four magnetic cores are flat, and the first magnetic core F1 and the second magnetic core F2 have the same specifications in terms of size, materials, etc., while the third magnetic core F3 and the fourth magnetic core F4 have the same specifications; preferably, all four magnetic cores can have the same specifications. The first coil W1 is isolated from the first magnetic core F1 by an insulating layer and is wound on the first magnetic core F1 in a predetermined direction; the second coil W2 is isolated from the second magnetic core F2 by an insulating layer and is wound on the second magnetic core F2 in the predetermined direction; the third coil W3 is isolated from the third magnetic core F3 by an insulating layer and is wound on the third magnetic core F3 in the predetermined direction; the fourth coil W4 is isolated from the fourth magnetic core F4 by an insulating layer and is wound on the fourth magnetic core F4 in the predetermined direction. The predetermined direction is explained below:

[0083] In practical applications, when an electric vehicle is parked in a parking space, there is a groove in the direction of entry and exit. Therefore, the vehicle's offset in the entry and exit direction is relatively small, while the offset in the direction perpendicular to the entry and exit direction is usually larger. Therefore, in the specific implementation of this invention, when installing the magnetic coupling system of this embodiment, it is required that the winding direction be substantially consistent with the vehicle's entry and exit direction. For example... Figure 5 As shown, if the winding direction is defined as the X direction, then the direction perpendicular to the X direction within the plane of the magnetic core in the primary or secondary magnetic coupling mechanism is the Y direction, and the direction perpendicular to both the X and Y directions is the Z direction. In this application, the inventors primarily optimize the anti-offset performance of the magnetic coupling system when it offsets in the X direction.

[0084] In this embodiment of the invention, in order to maintain the consistent characteristics of the magnetic coupling system in the positive and negative X directions, the first magnetic coupling mechanism 4011 and the second magnetic coupling mechanism 4012 can be mirror-symmetric, that is, symmetric with respect to the YOZ plane; the third magnetic coupling mechanism 4021 and the fourth magnetic coupling mechanism 4022 can also be mirror-symmetric, that is, symmetric with respect to the YOZ plane.

[0085] It should also be noted that, since a normal magnetic coupling effect needs to be generated between the primary and secondary coupling mechanisms, the winding direction and the magnetic pole direction need to meet relevant rules so that the best magnetic coupling effect can be generated when the primary and secondary magnetic coupling mechanisms are aligned, resulting in the best power transmission efficiency.

[0086] See Figure 6 , Figure 6 This is a first winding example diagram of the primary and secondary side magnetic coupling mechanism in an embodiment of the present invention. Specifically, Figure 6 In this configuration, the first coil W1 and the second coil W2 are wound with a single strand of wire and connected in series; the third coil W3 and the fourth coil W4 are also wound with a single strand of wire and connected in series. See also... Figure 7 , Figure 7 This is a second winding example diagram of the primary and secondary side magnetic coupling mechanism in an embodiment of the present invention. Specifically, Figure 7 In this design, the first coil W1 and the second coil W2 are wound with double-strand wire and connected in series; the third coil W2 and the fourth coil W4 are also wound with double-strand wire and connected in series. Compared with single-strand winding, double-strand winding can increase the coupling coefficient between the primary and secondary magnetic coupling mechanisms, reduce the coil resistance, reduce losses, and effectively improve transmission efficiency.

[0087] In practical applications, it is not recommended to have too many strands, because with the same winding space, the more strands there are, the smaller the number of turns, and the smaller the corresponding self-inductance, which may lead to a relatively poor magnetic coupling effect.

[0088] See Figure 8 , Figure 8 This is an embodiment of the present invention. Figure 7 Front view of the magnetic coupling system shown. See also Figure 9 , Figure 9 This is an embodiment of the present invention. Figure 7 A side view of the magnetic coupling system shown. (Combined with...) Figure 8 and Figure 9 The structural parameters of the magnetic coupling system in this embodiment of the invention are as follows:

[0089] The transmission distance between the primary and secondary magnetic coupling mechanisms, i.e., the transmitter T x With receiver R x The air gap size between them is l AG Transmitter T x With receiver R x The thicknesses are the same, let's call them H. Tx / Rx ;l STx This represents the first spacing value of the first air gap between the first coil W1 and the second coil W2, l SRxThis indicates the second spacing value of the second air gap between the third coil W3 and the fourth coil W4; Tx W is the first total length of the transmitter in the X direction. Tx The first total width of the transmitter in the Y direction; l Rx W is the second total length of the receiving end in the X direction. Rx The second total width of the receiving end in the Y direction; l FTx Indicates the lengths of the first magnetic core F1 and the second magnetic core F2, l FRx This indicates the lengths of the third magnetic core F2 and the fourth magnetic core F4; WTx W represents the lengths of the first coil W1 and the second coil W2. WTx This indicates the widths of the first coil W1 and the second coil W2; WRx This indicates the lengths of the third coil W3 and the fourth coil W4, W WRx This indicates the width of the third coil W3 and the fourth coil W4; the thickness of all four coils can be the same, represented by T. W Indicates that the thickness of the four magnetic cores can be the same, denoted by T. F This means that each coil and its corresponding magnetic core are isolated using acrylic material. Specifically, each magnetic core is placed inside an acrylic box, and the thickness of the box is the distance between each coil and its corresponding magnetic core. (C is used as the unit of measurement). WF This indicates that its size is exemplified by, for example, 3mm.

[0090] Based on the magnetic coupling system for a wireless charging system provided in the above embodiments of the present invention, the present invention also provides a method for optimizing the structural parameters of the magnetic coupling system for a wireless charging system, used to design the structural parameters of the magnetic coupling system for a wireless charging system, wherein the structural parameters may include: a first type of structural parameters and a second type of structural parameters. See also... Figure 10 , Figure 10 This is a flowchart of a structural parameter optimization method for a magnetic coupling system used in a wireless charging system according to an embodiment of the present invention. The process may include:

[0091] Step 1001: Predetermine the first type of structural parameters that do not require debugging and the second type of structural parameters that require debugging.

[0092] In this embodiment of the invention, the first type of structural parameters may include: the first total length of the primary side magnetic coupling mechanism 401 in the specified direction, and the second total length of the secondary side coupling mechanism 402 in the preset specified direction. The second type of structural parameters may include: a first spacing value and a second spacing value, wherein the first spacing value is the spacing between the first magnetic coupling mechanism 4011 and the second magnetic coupling mechanism 4012 in the primary side magnetic coupling mechanism 401, and the second spacing value is the spacing between the third magnetic coupling mechanism 4021 and the fourth magnetic coupling mechanism 4022 in the secondary side magnetic coupling mechanism 402, and the second spacing value is the spacing between the third magnetic coupling mechanism 4021 and the fourth magnetic coupling mechanism 4022.

[0093] Among the above structural parameters, the relationship between some structural parameters satisfies the following equation (1):

[0094]

[0095] In practical applications, the above l Tx l Rx W Tx W Rx and l AG Determined by the actual application scenario, it remains unchanged during the optimization process; T W T F C WF and H Tx / Rx The variation range of structural parameters is small, resulting in minimal impact on the performance and anti-offset capabilities of the magnetic coupling system, thus requiring no adjustments; regarding W Tx With W Rx During debugging, it was found that its impact on the anti-offset performance of the magnetic coupling system was unstable, indicating that it was not a major factor affecting the anti-offset performance; therefore, no debugging was required. Structural parameters that can be predetermined and do not require debugging can be collectively referred to as the first type of structural parameters. The structural parameters requiring debugging include: STx With l SRx .

[0096] Step 1002: Pre-select coupling performance parameters related to the anti-deflection performance of the magnetic coupling system of the present invention.

[0097] The coupling performance parameters may include: the coupling coefficient k of the magnetic coupling system of the present invention after it is offset in the specified direction, and the rate of change of the coupling coefficient CRR corresponding to the coupling coefficient, which reflects the anti-offset performance of the magnetic coupling system of the present invention in the specified direction.

[0098] As mentioned above, the embodiments of the present invention improve the anti-offset performance of the magnetic coupling system of the present invention in the X direction. Let k in the X direction be represented as k Δx The corresponding CRR can be represented as CRR Δx Δx represents the offset of the magnetically coupled system in the X direction, such as k.Δx＝100 CRR represents the coupling coefficient of the magnetic coupling system when it is offset by 100 mm in the X direction. Δx＝100 k represents the rate of change of the corresponding coupling coefficient. Δx With CRR Δx There is a corresponding relationship between them as shown in equation (2):

[0099]

[0100] Where, k ali This represents the coupling coefficient when the primary and secondary magnetic coupling mechanisms in the magnetic coupling system are aligned. From equation (2), it can be seen that, under normal circumstances, CRR... Δx The larger the value, the better the anti-offset performance of the magnetic coupling system.

[0101] Step 1003: Using the control variable method and in conjunction with the coupling performance parameters, adjust the second type of structural parameters to obtain the optimization results of the second type of structural parameters.

[0102] In this embodiment of the invention, a first empirical low threshold for the coupling coefficient and a second empirical low threshold for the rate of change of the coupling coefficient are preset; then step 1003 may specifically include:

[0103] A1: Determine the first spacing value l STx The parameter values ​​remain unchanged compared to those of the first type of structure;

[0104] B1: Change the offset Δx and the second spacing value l of the magnetic coupling system of the present invention in the specified direction, such as the X direction. SRx The corresponding coupling coefficient k is obtained. Δx With the rate of change of coupling coefficient CRR Δx ;

[0105] C1: Select the obtained coupling coefficient k Δx With the rate of change of coupling coefficient CRR Δx The second spacing value l when the preset selection conditions are met SRx To optimize the second spacing value l SRxe The selection criteria include: the coupling coefficient is greater than the first empirical low threshold k. PM Furthermore, the rate of change of the coupling coefficient is greater than the second empirical low threshold CRR. PM ;

[0106] D1: Determine the optimization result by comparing the first spacing value with the optimized second spacing value; or...

[0107] A2: Determine the second spacing value l SRx The parameter values ​​remain unchanged compared to those of the first type of structure;

[0108] B2: Change the offset Δx of the magnetic coupling system in the X direction and the first spacing value l of the present invention. STx The corresponding coupling coefficient and the rate of change of the coupling coefficient are obtained;

[0109] C2: Select the first spacing value that satisfies the preset selection conditions when the obtained coupling coefficient and the rate of change of the coupling coefficient meet the preset selection conditions. This value is the optimized first spacing value l. STxe ;

[0110] D2: Determine the optimization result by comparing the second spacing value with the optimized first spacing value.

[0111] In practical applications, if the coupling coefficient is too low, the power transmission efficiency will be low, rendering it unusable. In this embodiment of the invention, a first empirical low threshold k is listed. PM The CRR is 0.082, the second empirical low threshold. PM It is 0.55.

[0112] To obtain the optimal magnetic coupling mechanism, the embodiments of the present invention further consider the amount of material used in the magnetic coupling system. Specifically, in the embodiments of the present invention:

[0113] Pre-select material usage parameters that reflect the material usage of the magnetic coupling system of this invention;

[0114] The selected optimized second spacing value l SRxe The corresponding coupling material usage parameters meet the preset requirements; or,

[0115] The selected optimized first spacing value l STxe The corresponding coupling material usage parameters meet the preset requirements.

[0116] Specifically, the material usage parameters may include: coupling material volume V F and normalized inductance coefficient A Tx With A Rx In this embodiment of the invention, the normalized inductance coefficient is defined as shown in equation (3):

[0117]

[0118] Among them, A Tx L represents the normalized inductance coefficient of the primary-side magnetic coupling mechanism 401. Tx The value of self-inductance of the primary magnetic coupling mechanism 401 is represented by l. LitzTx A represents the total winding length of the primary-side magnetic coupling mechanism 401; Rx L represents the normalized inductance coefficient of the secondary magnetic coupling mechanism 402. Rx The value of self-inductance of the secondary magnetic coupling mechanism 402 is represented by l. LitzRx This indicates the total winding length of the secondary magnetic coupling mechanism 402.

[0119] In the coupling coefficient k Δx With the rate of change of coupling coefficient CRR Δx Based on meeting the preset selection conditions, the material usage parameters are further examined to see if they meet the preset requirements. In this embodiment of the invention, the preset requirements mainly involve further filtering to ultimately select the first and second spacing values ​​corresponding to the case where the material usage parameters are displayed with a relatively small amount of material. This case is as shown in V. F The inductance is relatively small, and the normalized inductance is relatively large. A relatively large normalized inductance means that less wire is needed for the same self-inductance.

[0120] The following examples, using finite element simulation software, illustrate specific implementations of this invention. In the magnetic coupling system of this invention, the coil winding employs double-strand winding. Furthermore, the finite element simulation software is a common tool in this industry and will not be described in detail.

[0121] Refer to Table 1, which lists the parameters that do not require adjustment during the structural parameter optimization process in this embodiment of the invention:

[0122]

[0123] Table 1

[0124] See Figure 11 , Figure 11 This is a first example diagram showing the result of debugging the second type of structural parameters based on the control variable method in an embodiment of the present invention. Figure 11 In the middle, set l SRx The value remains unchanged at -12.4mm. The reason this value is negative is that the third and fourth magnetic cores are merged into one magnetic core, and there is no air gap, winding, or isolation layer between them, which is similar to the secondary magnetic coupling mechanism in existing magnetic coupling systems. Figure 11 In the figure, the vertical axis represents the coupling coefficient k. Δx The horizontal axis represents the offset (offset distance) Δx of the magnetic coupling system of the present invention in the X direction and the aforementioned first total length l. Tx The reason for choosing this ratio, instead of directly using the offset Δx, is to further demonstrate the outstanding performance of the magnetic coupling system of this invention in terms of anti-offset capabilities. This will be explained below through comparisons of relevant content.

[0125] Figure 11 The text provides four first spacing values ​​l STx The four possible values ​​were selected from numerous experimental values, and the coupling coefficient k was chosen. Δx For graphs with a value above 0.08, discard the less significant parts. Figure 11 The data is explained as follows:

[0126] Offset Δx and first total length l Tx The ratio changes from 0 to 65.3%, meaning the offset Δx changes from 0 to 400 mm. Where, l SRx =l STx The case of -12.4mm is equivalent to an existing magnetic coupling system. When l SRx =l STx = -12.4mm, when the offset Δx reaches 400mm, the rate of change of the coupling coefficient CRR Δx＝400 =0.496; when l STx =87.6mm, Coupling coefficient change rate CRR Δx＝400 =0.513; when l STx =187.6mm, Coupling coefficient change rate CRR Δx＝400 =0.582; when l STx =287.6mm, Coupling coefficient change rate CRR Δx＝400 =0.631. Data shows that the anti-offset performance of the magnetic coupling system of this invention is significantly better than that of existing magnetic coupling systems.

[0127] See Figure 12 , Figure 12 This is a second example diagram showing the result of debugging the second type of structural parameters based on the control variable method in an embodiment of the present invention. Figure 12 Setting l SRx The thickness remains unchanged at 87.6mm; the specific meaning of this data is the same as... Figure 11 Similar to the above, so I will not elaborate further.

[0128] See Figure 13 , Figure 13 This is a third example diagram showing the result of debugging the second type of structural parameters based on the control variable method in an embodiment of the present invention. Figure 13 Setting l SRx The thickness remains unchanged at 187.6 mm; the specific meaning of this data is the same as... Figure 11 Similar to the above, so I will not elaborate further.

[0129] See Table 2, which is a list of simulation results in the embodiments of the present invention:

[0130]

[0131] Table 2

[0132] As shown in Table 2, cases 3, 4, and 7 meet the requirements, that is, they satisfy k. Δx＝400 ≥0.082, and CRR Δx＝400 Given the condition of ≥0.55, and based on the data in Table 2 regarding material usage parameters, cases 4 and 7 are superior. In practice, the typical dimensions of ferrite cores are 100×100×10mm. 3and 100×50×10mm 3 In scenario 4, two 50×50×10mm pieces are required. 3 Considering all factors, option 7 was selected as the final optimized result for the ferrite core. The volume of the magnetic coupling system of this invention and the existing magnetic coupling system are 2×10⁶ mm². 3 and 2.75×106mm 3 The optimized ferrite core usage is reduced by 27.3%. Comparing the copper usage for winding under the same self-inductance, the magnetic coupling system of this invention reduces the copper usage of the primary and secondary magnetic coupling mechanisms by 18.6% and 9.2%, respectively, compared to existing magnetic coupling systems. Therefore, the magnetic coupling system of this invention significantly improves anti-misalignment performance while reducing cost and weight.

[0133] Based on the above-mentioned structural parameter optimization method and simulation experiments, the inventors drew the following empirical conclusions:

[0134]

[0135] See Figure 14 , Figure 14 This is an example diagram of the effective magnetic region when the magnetic coupling system is facing each other in an embodiment of the present invention. See also... Figure 15 , Figure 15 This is an example diagram of the effective magnetic region of the magnetic coupling system in an embodiment of the present invention when it undergoes a 100mm offset in the X direction. See also... Figure 16 , Figure 16 This is an example diagram of the effective magnetic region of the magnetic coupling system in an embodiment of the present invention when there is a 200mm offset in the X direction. See also... Figure 17 , Figure 17 This is an example diagram of the effective magnetic region of the magnetic coupling system in an embodiment of the present invention when it undergoes a 300mm offset in the X direction. See also... Figure 18 , Figure 18 This is an example diagram of the effective magnetic region of the magnetic coupling system in an embodiment of the present invention when it undergoes a 400mm offset in the X direction. Figures 14 to 18 The comparison shows that after the magnetic coupling system of the present invention is deflected, compared with the upright case, the area of ​​its effective magnetic region remains almost unchanged, and the magnetic field weakens only slightly, thus verifying the strong anti-deflection performance of the magnetic coupling system of the present invention.

[0136] In summary, in the embodiments of the present invention, the inventors have... Figure 2 The loosely coupled transformer structure shown is to be improved by considering removing... Figure 2The magnetic core in the middle part of the primary and secondary magnetic coupling mechanism shown can ensure anti-offset performance while occupying the same space volume, effectively reduce the weight of the magnetic coupling system itself, and reduce the amount of winding, thereby effectively reducing costs. It also helps to reduce the design difficulty of DC / DC modules and promotes the industrialization of wireless charging.

[0137] Those skilled in the art will understand that all or part of the processes of the methods described in the above embodiments can be implemented by a computer program instructing related hardware, and the program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a disk, optical disk, read-only memory, or random access memory, etc.

[0138] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for optimizing the structural parameters of a magnetic coupling system for a wireless charging system, characterized in that, The magnetic coupling system for the wireless charging system includes: a primary-side magnetic coupling mechanism and a secondary-side magnetic coupling mechanism, which are capable of generating a magnetic coupling effect. The primary-side magnetic coupling mechanism includes: a first magnetic coupling mechanism and a second magnetic coupling mechanism; the secondary-side magnetic coupling mechanism includes: a third magnetic coupling mechanism and a fourth magnetic coupling mechanism; the first magnetic coupling mechanism and the second magnetic coupling mechanism are arranged in the same plane and have a first air gap, and are connected in series by a winding; the third magnetic coupling mechanism and the fourth magnetic coupling mechanism are arranged in the same plane and have a second air gap, and are connected in series by a winding. The structural parameters include: a first type of structural parameters and a second type of structural parameters. The first type of structural parameters includes: the first total length of the primary side magnetic coupling mechanism in a preset specified direction, and the second total length of the secondary side magnetic coupling mechanism in the specified direction. The method includes: pre-determining a first type of structural parameters that do not require debugging and a second type of structural parameters that require debugging. The second type of structural parameters includes a first spacing value and a second spacing value. The first spacing value is the size of the first air gap between the first and second magnetic coupling mechanisms in the primary side magnetic coupling mechanism; the second spacing value is the size of the second air gap between the third and fourth magnetic coupling mechanisms in the secondary side magnetic coupling mechanism; pre-selecting coupling performance parameters related to the anti-offset performance of the magnetic coupling system; the coupling performance parameters include: the coupling coefficient of the magnetic coupling system after offset in the specified direction, and the rate of change of the coupling coefficient corresponding to the coupling coefficient, which reflects the anti-offset performance of the magnetic coupling system in the specified direction; and pre-setting a first empirical low threshold for the coupling coefficient and a second empirical low threshold for the rate of change of the coupling coefficient. Using the control variable method and in conjunction with the coupling performance parameters, the second type of structural parameters are adjusted to obtain the optimized results of the second type of structural parameters, including: The first spacing value and the first type of structural parameter value are kept unchanged; the offset of the magnetic coupling system in the specified direction and the second spacing value are changed to obtain the corresponding coupling coefficient and the rate of change of the coupling coefficient; the second spacing value that satisfies the obtained coupling coefficient and the rate of change of the coupling coefficient satisfy a preset selection condition is selected as the optimized second spacing value, the selection condition including: the coupling coefficient is greater than the first empirical low threshold, and the rate of change of the coupling coefficient is greater than the second empirical low threshold; the first spacing value and the optimized second spacing value are determined as the optimization result; or, The second spacing value and the first type of structural parameter value are kept unchanged; the offset of the magnetic coupling system in the specified direction and the first spacing value are changed to obtain the corresponding coupling coefficient and the rate of change of the coupling coefficient; the first spacing value that satisfies the obtained coupling coefficient and the rate of change of the coupling coefficient satisfy the preset selection conditions is selected as the optimized first spacing value; the second spacing value and the optimized first spacing value are determined as the optimization result.

2. The method for optimizing the structural parameters of a magnetic coupling system for a wireless charging system according to claim 1, characterized in that, The first magnetic coupling mechanism includes: a first coil and a first magnetic core; The second magnetic coupling mechanism includes: a second coil and a second magnetic core; The third magnetic coupling mechanism includes: a third coil and a third magnetic core; The fourth magnetic coupling mechanism includes: a fourth coil and a fourth magnetic core; All four magnetic cores are flat, and the first magnetic core and the second magnetic core have the same specifications, and the third magnetic core and the fourth magnetic core have the same specifications; The first coil is isolated from the first magnetic core by an insulating layer and is wound on the first magnetic core in a predetermined direction; The second coil is isolated from the second magnetic core by an insulating layer and is wound on the second magnetic core in the predetermined direction; The third coil is isolated from the third magnetic core by an insulating layer and is wound on the third magnetic core in the preset specified direction; The fourth coil is isolated from the fourth magnetic core by an insulating layer and is wound on the fourth magnetic core in the preset specified direction.

3. The method for optimizing the structural parameters of a magnetic coupling system for a wireless charging system according to claim 2, characterized in that, The first coil and the second coil are wound with single-strand wire and connected in series; the third coil and the fourth coil are wound with single-strand wire and connected in series; or, The first coil and the second coil are wound with double-strand wire and connected in series; the third coil and the fourth coil are wound with double-strand wire and connected in series.

4. The method for optimizing the structural parameters of a magnetic coupling system for a wireless charging system according to any one of claims 1 to 3, characterized in that, The first magnetic coupling mechanism and the second magnetic coupling mechanism are mirror-symmetric. The third magnetic coupling mechanism is mirror-symmetric to the fourth magnetic coupling mechanism.

5. The method for optimizing the structural parameters of a magnetic coupling system for a wireless charging system according to claim 1, characterized in that, The structural parameter optimization method further includes: Pre-select coupling material usage parameters that reflect the material usage of the magnetic coupling system; The coupling material usage parameters corresponding to the selected optimized second spacing value meet the preset requirements; or, The coupling material usage parameters corresponding to the selected optimized first spacing value meet the preset requirements.

6. The method for optimizing the structural parameters of a magnetic coupling system for a wireless charging system according to claim 5, characterized in that, The parameters for the amount of coupling material used include: the volume of the coupling material and the normalized inductance coefficient; The normalized inductance coefficient includes: ， in, This represents the normalized inductance coefficient of the primary-side magnetic coupling mechanism. This represents the self-inductance value of the primary-side magnetic coupling mechanism. This represents the total winding length of the primary-side magnetic coupling mechanism; This represents the normalized inductance coefficient of the secondary magnetic coupling mechanism. This represents the self-inductance value of the secondary magnetic coupling mechanism. This indicates the total winding length of the secondary magnetic coupling mechanism.

7. The method for optimizing the structural parameters of a magnetic coupling system for a wireless charging system according to claim 5 or 6, characterized in that, ， in, The first spacing value, This is the first total length; This is the second spacing value. This is the second total length.

Images