An anti-offset wireless charging magnetic coupler based on magnetic field complementarity and design method

Abstract

The present invention discloses an anti-offset wireless charging magnetic coupler and design method based on magnetic field complementarity, which belongs to the field of wireless power transmission technology. The coupler includes: a primary side, including a primary side first coil and a primary side magnetic core plate, the primary side first coil is wound on the upper surface of the primary side magnetic core plate; a secondary side, including a secondary side first coil, a secondary side second coil, a secondary side magnetic core plate and a secondary side convex magnetic core, the secondary side second coil surrounds the magnetic core plate and is wound in the middle position of the secondary side magnetic core plate, the secondary side convex magnetic core is arranged on the upper surface of the secondary side magnetic core plate, and the upper half of the secondary side second coil is nested in the convex groove of the convex magnetic core; the secondary side first coil is wound on the lower surface of the secondary side magnetic core plate and is arranged orthogonally to the secondary side first coil; wherein the secondary side first coil generates or receives a vertical magnetic field, and the secondary side second coil generates or receives a parallel magnetic field. The magnetic coupler of the present invention realizes magnetic field fluctuation suppression based on the principle of magnetic field compensation complementarity, thereby realizing the anti-offset characteristics of the coupler.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless power transmission, and in particular to an anti-offset wireless charging magnetic coupler based on magnetic field complementarity and a design method thereof. Background Art

[0002] Inductive Power Transfer (IPT) is a technology that transmits electrical energy through magnetic coupling without the need for wire connections. This technology is safe, efficient, flexible and convenient, and does not require traditional direct electrical connections and mechanical plug-ins. Therefore, it is considered a very promising and friendly technology and has received extensive attention and research from scientists. Currently, IPT is widely used in fields such as implantable medical devices, consumer electronics, electric vehicles, and underwater operations, and has obvious advantages. However, in most actual IPT applications, such as electric vehicle charging, it is difficult to accurately align the parking position, which will cause the mutual inductance and coupling coefficient of the magnetic coupling mechanism to change, which in turn has a significant impact on the output power and efficiency of the IPT system. Therefore, improving the anti-offset characteristics of the coupler is the key to solving the system robustness.

[0003] The current anti-offset design of couplers can be summarized into three aspects. The first is to design a traditional symmetrical magnetic coupler through parameter optimization. This method can only slow down the attenuation of the magnetic field and does not have good anti-offset characteristics. The second is the asymmetric design of a large transmitter matching a small receiver. However, this design method has only relatively limited anti-offset characteristics and the overall coupling coefficient of the coupler is low, which increases costs or requires additional control measures. The third is to construct multiple coupled mutual inductances with the same attenuation by winding multiple coils in opposite directions to achieve the anti-offset characteristics of the coupler. However, this method is based on the mechanism of reverse cancellation, which reduces the energy transmission capacity of the coupler and has the problem of cross-coupling. Summary of the Invention

[0004] In order to at least partially solve one of the technical problems existing in the prior art, the present invention aims to provide an anti-drift wireless charging magnetic coupler based on magnetic field complementarity and a design method thereof.

[0005] The technical solution adopted in the present invention is:

[0006] A magnetic field complementary-based anti-offset wireless charging magnetic coupler, comprising:

[0007] The primary side includes a primary first coil and a primary magnetic core plate, wherein the primary first coil is wound on the upper surface of the primary magnetic core plate;

[0008] The secondary side includes a first secondary coil, a second secondary coil, a secondary magnetic core plate and a secondary convex magnetic core. The second secondary coil surrounds the magnetic core plate and is wound in the middle position of the secondary magnetic core plate. The secondary convex magnetic core is arranged on the upper surface of the secondary magnetic core plate, and the upper half of the second secondary coil is nested in the raised groove of the convex magnetic core; the first secondary coil is wound on the lower surface of the secondary magnetic core plate and is arranged orthogonally to the first secondary coil; wherein the first secondary coil generates or receives a vertical magnetic field, and the second secondary coil generates or receives a parallel magnetic field. Therefore, the coils of the secondary side are decoupled from each other, avoiding the circulating current problem caused by cross-coupling on the same side; the primary / secondary magnetic core plates enhance the transmission capacity of the magnetic coupler and reduce magnetic field exposure.

[0009] In operation, the upper surface of the primary magnetic core plate faces the lower surface of the secondary magnetic core plate. The upper half of the secondary second coil is nested in the raised groove of the convex magnetic core, which can further suppress the magnetic field exposure of the secondary second coil.

[0010] Furthermore, the anti-drift wireless charging magnetic coupler realizes the anti-drift capability of the magnetic coupler based on the principle of magnetic field complementarity;

[0011] When one (vertical) magnetic flux decays with the offset (△X or △Y), the other (horizontal) magnetic flux changes in the opposite direction, thus playing a mutual compensation role, ensuring that the effective energy transmission flux of the magnetic coupler remains constant within a certain offset range, and realizing the anti-offset capability of the wireless energy transmission system.

[0012] Furthermore, the mutual inductance of the anti-offset wireless charging magnetic coupler is expressed as:

[0013]

[0014] Where, Φ TS,Ver The first coil on the secondary side captures the vertical magnetic flux from the first coil on the primary side, Φ TS,Hor The second coil on the secondary side captures the horizontal magnetic flux generated by the first coil on the primary side, I T is the excitation current of the first coil of the primary side, M TR and M TS are the mutual inductances between the first primary coil and the first secondary coil and the second secondary coil respectively.

[0015] In order to improve the misalignment tolerance of the coupler, it is necessary to ensure that the mutual inductance M of the coupler is Total Keep it as consistent as possible within a certain range of misalignment.

[0016] Another technical solution adopted in the present invention is:

[0017] A design method for designing an anti-drift wireless charging magnetic coupler includes the following steps:

[0018] Performing linearization processing on the relationship between the mutual inductance and the offset of the anti-offset wireless charging magnetic coupler to determine the structural parameters of the anti-offset wireless charging magnetic coupler;

[0019] The linearization process includes: linearizing the mutual inductance and offset of the coupling between the primary first coil and the secondary first coil, and / or linearizing the mutual inductance and offset of the coupling between the primary first coil and the secondary second coil.

[0020] Furthermore, the linearization of the coupling mutual inductance and offset between the primary first coil and the secondary second coil includes:

[0021] The mutual inductance M between the secondary side second coil and the primary side first coil TS Defined as compensated mutual inductance;

[0022] As the number of turns of the secondary second coil N S Increase, compensate mutual inductance M TS Under misalignment conditions, the mutual inductance M will also increase and compensate TS First increase, then decrease; for different number of turns N S , compensate mutual inductance M TS The inflection point occurs at the same position; before reaching the extreme value of the mutual inductance, the mutual inductance M is compensated. TS It is approximately linearly related to the primary / secondary misalignment distance of the magnetic coupler; therefore, the mutual inductance M TS The linear representation of the offset distance △X between the primary and secondary sides of the magnetic coupler, and the compensation mutual inductance M TS The relationship between the offset distance △X and the original secondary side is expressed by a linear equation as follows:

[0023] M TS ≈k TS ΔX

[0024] Where k TS To compensate for the mutual inductance M TS Compensation slope after linearization with offset distance △X.

[0025] Furthermore, the linearization of the mutual inductance and offset of the coupling between the primary first coil and the secondary first coil includes:

[0026] The mutual inductance M between the secondary first coil and the primary first coil TR As the offset △X increases, it decreases and shows an obvious linear relationship. Based on this, the mutual inductance M is constructed. TR The linear modeling of the offset △X curve is as follows:

[0027] M TR ≈k TR ΔX+M TR0

[0028] Where k TR Mutual inductance M TR Approximate slope after linearization with offset distance △X, M TR0 is the initial value of mutual inductance.

[0029] Furthermore, the design method further comprises an optimization step:

[0030] As the offset △X increases, the compensation slope k TS and compensation slope k TR They should be opposite to each other and approximately equal. Based on this, the optimization design criteria of the anti-offset wireless charging magnetic coupler are summarized as follows:

[0031]

[0032] Furthermore, determining the structural parameters of the anti-offset wireless charging magnetic coupler includes:

[0033] Determine the size parameters of the primary and secondary first coils based on the input and output parameter requirements of the IPT system;

[0034] According to the mutual inductance characteristics of the primary first coil and the secondary first coil and the preset expected offset range, the initial mutual inductance M of the primary first coil and the secondary first coil is obtained. TR0 , and the mutual inductance M at maximum offset TR,min , and calculate the approximate slope k TR ;

[0035] According to the approximate slope k TR Design the second coil on the secondary side.

[0036] Furthermore, the approximate slope k TR Design the secondary coil, including:

[0037] Set the initial number of turns N of the secondary coil S0 (N S0 >1), get the minimum value M of the compensation mutual inductance TS | min and the maximum value M TS | max , and record the offset △X corresponding to the maximum value of the compensation mutual inductance, and calculate the compensation slope k according to the linear method TS ;

[0038] If |k TR | <k TS , then reduce the number of turns N of the second coil on the secondary side S , that is, N S =N S0 -1; if |kTR |>k TS , then increase the number of turns N of the second coil on the secondary side S , that is, N S =N S0 +1; if |k TR |≈k TS , then the optimal design parameters of the output coupler.

[0039] Furthermore, the minimum value M of the compensated mutual inductance is obtained TS | min and the maximum value M TS | max ,include:

[0040] Using FEA method to obtain the minimum value M of the compensated mutual inductance TS | min and the maximum value M TS | max .

[0041] The present invention has the following advantages and effects compared to the prior art:

[0042] (1) The present invention is based on the principle of magnetic field complementarity to effectively suppress the coupling magnetic field fluctuation under offset conditions, improve the anti-offset capability and power transmission capability of the magnetic coupler, and achieve output stability of the IPT charging system and high efficiency throughout the offset range.

[0043] (2) The magnetic coupler of the present invention can receive vertical magnetic fields and horizontal magnetic fields at the same time, can couple unipolar or bipolar coupler pads, and the vertical magnetic field and the horizontal magnetic field have complementary characteristics at different offsets, and have strong anti-offset ability and interoperability.

[0044] (3) The coupler of the present invention is applicable to all wireless charging systems with compensation networks. It does not rely on active control and does not require additional communication modules and detection devices. It can achieve relatively outstanding anti-drift capability, making the IPT system have good robustness.

[0045] (4) The linearization slope fast matching optimization design method of the present invention can quickly locate the optimal anti-drift design parameters of the magnetic coupler and achieve optimized design. Compared with the traditional repeated parameter scanning design method, it can improve design efficiency and reduce the requirements for computer hardware, thus saving costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following introduction is made to the drawings of the embodiments of the present invention or the related technical solutions in the prior art. It should be understood that the drawings introduced below are only for the convenience of clearly describing some embodiments of the technical solutions of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative work.

[0047] Figure 1 1 is a schematic structural diagram of an anti-offset wireless charging magnetic coupler based on magnetic field complementarity according to an embodiment of the present invention;

[0048] Figure 2 yes Figure 1 Schematic diagram of the working mechanism of the coupler;

[0049] Figure 3 Schematic diagram of the change of effective magnetic flux of the coupler with offset in an embodiment of the present invention;

[0050] Figure 4 Schematic diagram of the change of the mutual inductance of the coupler with the offset in an embodiment of the present invention;

[0051] Figure 5 is a schematic diagram of mutual inductance linearization of a coupler according to an embodiment of the present invention;

[0052] Figure 6 This is the process of the anti-offset optimization design method of the coupler in an embodiment of the present invention;

[0053] Figure 7 2. Schematic diagram of the change of mutual inductance with offset after optimization of the coupler based on the linearized slope fast matching method in an embodiment of the present invention;

[0054] Figure 8 is based on Figure 7 Schematic diagram of the anti-offset performance of the magnetic coupler after the design method is optimized.

[0055] The reference numerals are described as follows: 100 - secondary side, 101 - first secondary coil, 102 - second secondary coil, 103 - secondary magnetic core plate, 104 - secondary convex magnetic core, 200 - primary side, 201 - first primary coil, 202 - primary magnetic core plate. DETAILED DESCRIPTION

[0056] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention and are not to be construed as limiting the present invention. The step numbers in the following embodiments are provided for ease of explanation only and do not limit the order of the steps. The order of execution of the steps in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0057] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0058] In the description of the present invention, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0059] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0060] Explanation of terms:

[0061] FEA: An engineering numerical analysis method used to solve complex physical problems. It breaks a complex structure into many small finite elements and then performs calculations on these elements to simulate and predict the structure's behavior. Finite element analysis is widely used in engineering fields such as mechanical, civil, and aerospace for designing and optimizing structures, predicting material properties, and simulating physical phenomena.

[0062] like Figure 1As shown, this embodiment discloses an anti-drift wireless charging magnetic coupler based on magnetic field complementarity, comprising a primary side 200 and a secondary side 100, wherein the primary side 200 includes a primary first coil 201 and a primary magnetic core plate 202; the secondary side 100 includes a secondary first coil 101, a secondary second coil 102, a secondary magnetic core plate 103, and a secondary convex magnetic core 104. The secondary second coil 102 is wound around the center of the secondary magnetic core plate 103 and arranged orthogonally to the secondary first coil 101. Because the secondary first coil 101 generates or receives a perpendicular magnetic field and the secondary second coil 102 generates or receives a parallel magnetic field, the coils of the secondary side 100 are decoupled from each other, avoiding the problem of circulating current caused by same-side cross-coupling. The primary / secondary magnetic core plates enhance the transmission capacity of the magnetic coupler and reduce magnetic field exposure; the secondary convex magnetic core 104 is arranged on the upper surface of the secondary magnetic core plate 103, and the upper half of the secondary second coil 102 is nested in the raised groove of the convex magnetic core 104, further suppressing the magnetic field exposure of the secondary second coil 102.

[0063] The magnetic coupler disclosed in the embodiment of the present invention realizes the anti-drift capability of the magnetic coupler based on the principle of magnetic field complementarity. Figure 2 When one magnetic flux Φ1 decays with the offset (△X or △Y), the other magnetic flux Φ2 has the opposite change trend, thereby achieving complementary protection. The effective energy transmission flux of the magnetic coupler remains constant within a certain offset range, realizing the anti-offset capability of the wireless energy transmission system. Figure 1 The magnetic coupler in can capture the effective vertical magnetic field and horizontal magnetic field at the same time. The first coil on the secondary side captures the vertical magnetic flux from the first coil on the primary side, which is set as Φ TR,Ver , the second coil on the secondary side captures the horizontal magnetic flux generated by the first coil on the primary side, set as Φ TS,Hor Their sizes depend on the offset of the primary / secondary sides of the magnetic coupler, so the effective flux hinge of the magnetic coupler disclosed in the present invention can be expressed as follows:

[0064] Φ Total =|Φ TS,Ver |+|Φ TS,Hor | (1)

[0065] According to the dimensional parameters in Table 1 and the total magnetic flux calculation formula passing through the closed surface (α represents the angle between the closed surface and the magnetic flux density vector B):

[0066] Φ=φ s B cos α dS (2)

[0067] The vertical magnetic flux Φ of the magnetic coupler under different offset conditions can be calculated separately TR,Ver and horizontal magnetic flux Φ TS,Hor Specific reference Figure 3 , it can be seen that the magnetic coupler disclosed in the embodiment of the present invention captures the vertical magnetic flux ΦTR,Ver and horizontal magnetic flux Φ TS,Hor The relationship with the magnetic coupler offset has a complementary characteristic. That is, as the secondary side offset increases, the effective vertical magnetic flux Φ TR,Ver Gradually decreases, on the contrary, the effective horizontal magnetic flux Φ TR,Ver Therefore, the magnetic coupler disclosed in the embodiment of the present invention has the ability to complement the magnetic field. If the parameters of the coupler are effectively designed, it will have good anti-offset capability, thereby improving the robustness of wireless power transmission and ensuring output stability.

[0068] Table 1. Parameters of the magnetic coupler of the embodiment

[0069]

[0070]

[0071] According to Neumann's formula and formula (1), the mutual inductance of the magnetic coupler is expressed as follows:

[0072]

[0073] Among them I T is the excitation current of the primary first coil, which is set to 10A in this embodiment, and M Total is the total mutual inductance of the magnetic coupler, M TR and M TS are the mutual inductances between the primary first coil, the secondary first coil and the spiral coil.

[0074] According to formula (3), in order to improve the misalignment tolerance capability of the IPT coupler proposed in the embodiment of the present invention, it is necessary to ensure that the mutual inductance M of the coupler is Total Keep the same position as much as possible within a certain offset range. Considering that the structure and external dimensions of the coupler are generally based on the design recommendations in SAE J2954, when the structural dimensions of the coupler are determined, an important factor affecting the coupling effect of the IPT coupler is the number of turns in the coil. TS Defined as the compensation mutual inductance. Based on the size parameters in Table 1, the number of turns N of the second coil on the secondary side is different. S The relationship between the mutual inductance of the magnetic coupler and the offset distance △X disclosed in the embodiment of the present invention is as follows: Figure 4 , with the secondary side second coil N S The increase of M TS Under misalignment conditions, the mutual inductance M will also increase and compensate TS First increases, then decreases. For different turns N S , compensate mutual inductance M TSThe inflection point occurs at the same location. For example, the inflection point in the recommended design (i.e., the maximum point of the compensation mutual inductance) is located at ΔX| max =120mm offset distance, which is about 40% of the coupler size in parameter table 1. However, before reaching the maximum value of the compensation mutual inductance, the compensation mutual inductance M TS It is approximately linearly related to the primary / secondary misalignment distance of the magnetic coupler. Therefore, the compensation mutual inductance M TS The linear representation of the offset distance △X between the primary and secondary sides of the magnetic coupler is shown in the following table: Figure 5 Based on this, the compensation mutual inductance M TS The relationship between the offset distance △X can be expressed by a linear equation as follows:

[0075] M TS ≈k TS ΔX(4)

[0076] where k TS To compensate for the mutual inductance M TS The approximate compensation slope after linearization with the offset distance △X is expressed as:

[0077]

[0078] In addition, reference Figure 4 As can be seen from the solid red curve in the figure, the mutual inductance M between the secondary first coil and the primary first coil of the anti-offset wireless charging magnetic coupler based on magnetic field complementarity disclosed in the embodiment of the present invention is TR As the offset △X increases, it decreases and shows an obvious linear relationship. Therefore, as shown in Reference 5, the mutual inductance M TR The offset △X curve can also be linearly modeled as follows:

[0079] M TR ≈k TR ΔX+M TR0 (6)

[0080] Among them, k TR Mutual inductance M TR Approximate slope after linearization with offset △X, M TR0 represents the initial value of the mutual inductance when the first coil of the secondary side and the first coil of the primary side of the proposed magnetic coupler are fully aligned. Based on equations (4) and (6), in order to achieve an almost constant effective coupling flux of the magnetic coupler and ensure the stability of the IPT system, as the offset △X increases, the compensation slope k TS and k TR They should be opposite to each other and approximately equal. Therefore, the following design guidelines are given:

[0081] M TR +M TS ≈M TR0 (7)

[0082] k TR +k TS =0 (8)

[0083] k TR The value of k is mainly determined by the design of the first coil of the primary / secondary side. The rectangular coil is responsible for power transmission and is usually designed according to the input and output parameters of the IPT system. Therefore, k can be adjusted by designing the second coil of the secondary side. TS Satisfy formula (8) to achieve better anti-drift capability. The detailed design method flow is referenced in Figure 6 .

[0084] See also Figure 6 Based on the above, the design method of the anti-offset wireless charging magnetic coupler includes:

[0085] S1. First, determine the size parameters of the main energy transmission coils, i.e. the first coils on the primary and secondary sides, based on the input and output parameter requirements of the IPT system, including the application scenarios.

[0086] S2. Secondly, according to the mutual inductance characteristics of the primary and secondary first coils and the expected offset range, the FEA method is used to obtain the initial mutual inductance M of the primary and secondary first coils. TR0 And the mutual inductance M at maximum offset TR,min , the approximate slope k is calculated based on the above linearization method TR .

[0087] S3, finally according to the approximate slope k TR Design the secondary coil. First, set the initial number of turns N of the secondary coil. S0 (N S0 >1), and obtain the minimum value of the compensated mutual inductance M through the FEA method TS | min and the maximum value M TS | max Then record the maximum value of the mutual inductance compensation point as the corresponding offset △X, and then calculate the approximate compensation slope k according to the above linear method TS Based on the design criteria (7) and (8), if |k TR | <k TS , then reduce the number of turns N of the second coil on the secondary side S , that is, N S =N S0 -1; if |k TR |>k TS , then increase the number of turns N of the second coil on the secondary side S , that is, N S =N S0 +1; if |k TR |≈k TS, then the optimal design parameters of the output coupler.

[0088] This method only requires one parameter sweep to obtain M in the process of magnetic coupler anti-offset design. TS | max The position where it appears, that is, the offset △X, can quickly obtain the approximate slope k TR With k TS , thus quickly locating the optimal anti-drift design parameters. Compared with traditional repeated parameter sweep design methods, this can improve design efficiency and reduce the requirements for computer hardware.

[0089] Based on the above-mentioned optimization design method for fast slope matching, the magnetic coupler in the embodiment disclosed in the present invention is optimized, wherein the parameters of the primary and secondary first coils and the outer contour size parameters of the secondary second coil of the magnetic coupler are referred to Table 1. The approximate slope k of the coupling between the primary and secondary first coils is TR About -0.174, compensation slope k TS The relationship between the number of turns of the secondary second coil and the compensation slope k is shown in Table 2. Table 2 shows that when the number of turns of the secondary second coil is 9, the compensation slope k TS =0.169, approximately equal to |k TR |=0.174. Therefore, when the number of turns of the secondary second coil is N S =9, the specific mutual inductance characteristics of the magnetic coupler of the embodiment disclosed in the present invention under different offset conditions are referenced to Figure 7 and Figure 8 . Figure 8 is the total effective mutual inductance M of the coupler under different offset conditions Total The total mutual inductance M under the condition of perfect alignment Total,align The closer the ratio is to 1, the better the coupler's ability to suppress magnetic field fluctuations is. Figure 7 and Figure 8 It can be seen that under different offset conditions, the mutual inductance M of the primary and secondary first coils is TR The compensation mutual inductance M between the primary first coil and the secondary second coil TS The coupler of the embodiment disclosed in the present invention has an outstanding anti-drift capability because of its good complementary characteristics. In addition, the mutual inductance (i.e., same-side cross coupling) of the first coil and the spiral coil on the secondary side is M. RS It is close to 0, so the coil on the same side has good decoupling characteristics, avoiding the influence of circulating current on the IPT system.

[0090] Table 2 Relationship between linearization slope and number of turns

[0091]

[0092]

[0093] In the above description of this specification, reference to the terms "one embodiment / example," "another embodiment / example," or "certain embodiments / examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0094] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

[0095] The above is a specific description of the preferred implementation of the present invention, but the present invention is not limited to the above embodiments. Those skilled in the art can make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A design method for designing an anti-drift wireless charging magnetic coupler, characterized in that: The following steps are involved: Performing linearization processing on the relationship between the mutual inductance and the offset of the anti-offset wireless charging magnetic coupler to determine the structural parameters of the anti-offset wireless charging magnetic coupler; The linearization process includes: linearizing the mutual inductance and offset of the coupling between the first primary coil and the first secondary coil, and linearizing the mutual inductance and offset of the coupling between the first primary coil and the second secondary coil; Determining the structural parameters of the anti-offset wireless charging magnetic coupler includes: According to the input and output parameter requirements of the IPT system, the size parameters of the primary first coil and the secondary first coil are determined; according to the mutual inductance characteristics of the primary first coil and the secondary first coil and the preset expected offset range, the initial mutual inductance M between the primary first coil and the secondary first coil is obtained. TR0 , and the mutual inductance M at maximum offset TR,min , and calculate the approximate slope k TR ; According to the approximate slope k TR Design the second coil on the secondary side; The approximate slope k TR Design the secondary coil, including: Set the initial number of turns N of the secondary coil S0 , get the minimum value of the compensated mutual inductance and maximum value And record the offset △X corresponding to the maximum point of the compensation mutual inductance, and calculate the compensation slope k according to the linear method TS ; If |k TR | <k TS , then reduce the number of turns N of the second coil on the secondary side S ; If |k TR |>k TS , then increase the number of turns N of the second coil on the secondary side S ; If |k TR |≈k TS , then the optimal design parameters of the output coupler.

2. The design method according to claim 1, characterized in that: The linearized mutual inductance and offset of the coupling between the primary first coil and the secondary second coil include: The mutual inductance M between the secondary side second coil and the primary side first coil TS Defined as compensated mutual inductance; As the number of turns of the secondary second coil N S Increase, compensate mutual inductance M TS Under misalignment conditions, the mutual inductance M will also increase and compensate TS First increase, then decrease; before reaching the maximum value of mutual inductance, compensate for the mutual inductance M TS It is approximately linearly related to the primary / secondary misalignment distance of the magnetic coupler; therefore, the mutual inductance M TS The linear representation of the offset distance △X between the primary and secondary sides of the magnetic coupler, and the compensation mutual inductance M TS The relationship between the offset distance △X and the original secondary side is expressed by a linear equation as follows: M TS ≈k TS ΔX Where k TS To compensate for the mutual inductance M TS Compensation slope after linearization with offset distance △X.

3. The design method according to claim 2, characterized in that: The linearized mutual inductance and offset of the coupling between the primary first coil and the secondary first coil include: The mutual inductance M between the secondary first coil and the primary first coil TR As the offset △X increases, it decreases and presents a linear relationship. Based on this, the mutual inductance M is constructed. TR The linear modeling of the offset △X curve is as follows: M TR ≈k TR ΔX+M TR0 Where k TR Mutual inductance M TR Approximate slope after linearization with offset distance △X, M TR0 is the initial value of mutual inductance.

4. The design method according to claim 3, characterized in that: The design method further comprises an optimization step: As the offset △X increases, the compensation slope k TS and compensation slope k TR They should be opposite to each other and approximately equal. Based on this, the optimization design criteria of the anti-offset wireless charging magnetic coupler are summarized as follows:

5. The design method according to claim 1, characterized in that: The minimum value of the compensation mutual inductance is obtained and maximum value include: Using FEA method to obtain the minimum value of compensated mutual inductance and maximum value 6. A magnetic field complementarity-based anti-offset wireless charging magnetic coupler, designed using the method described in any one of claims 1 to 5, characterized in that: include: The primary side includes a primary first coil and a primary magnetic core plate, wherein the primary first coil is wound on the upper surface of the primary magnetic core plate; The secondary side includes a secondary side first coil, a secondary side second coil, a secondary side magnetic core plate and a secondary side convex magnetic core. The secondary side second coil surrounds the magnetic core plate and is wound in the middle position of the secondary side magnetic core plate. The secondary side convex magnetic core is arranged on the upper surface of the secondary side magnetic core plate, and the upper half of the secondary side second coil is nested in the raised groove of the convex magnetic core; the secondary side first coil is wound on the lower surface of the secondary side magnetic core plate and is arranged orthogonally to the secondary side first coil; wherein, the secondary side first coil generates or receives a vertical magnetic field, and the secondary side second coil generates or receives a parallel magnetic field.

7. The anti-offset wireless charging magnetic coupler based on magnetic field complementarity according to claim 6, characterized in that: The anti-drift wireless charging magnetic coupler realizes the anti-drift capability of the magnetic coupler based on the principle of magnetic field complementarity; When one magnetic flux decays with the offset, the other magnetic flux changes in the opposite direction, thus playing a mutual compensation role, ensuring that the effective energy transmission flux of the magnetic coupler remains constant within a certain offset range, and realizing the anti-offset capability of the wireless energy transmission system.

8. The anti-offset wireless charging magnetic coupler based on magnetic field complementarity according to claim 6, characterized in that: The mutual inductance of the anti-offset wireless charging magnetic coupler is expressed as: Where, Φ TS,Ver The first coil on the secondary side captures the vertical magnetic flux from the first coil on the primary side, Φ TS,Hor The second coil on the secondary side captures the horizontal magnetic flux generated by the first coil on the primary side, I T is the excitation current of the first coil of the primary side, M TR and M TS are the mutual inductances between the first primary coil and the first secondary coil and the second secondary coil respectively.

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