Wireless electric energy transmission device

Abstract

The invention discloses a wireless electric energy transmission device which comprises a transmitting coil, a magnetic negative metamaterial plate and a receiving coil. The magnetic negative metamaterial plate is arranged on one side of the transmitting coil, and the receiving coil is arranged on one side, far away from the transmitting coil, of the magnetic negative metamaterial plate; the magnetic negative metamaterial plate comprises n * n resonance elements arranged in a matrix, and each resonance element comprises a substrate and a planar coil wound by a conductive wire; the planar coil is laid on the surface of the substrate; the shape of the planar coil is a regular pattern, magnetic field focusing is achieved, the coupling effect between the transmitting coil and the receiving coil is enhanced, the transmission magnetic field intensity is improved, and the influence of the transmission distance is reduced.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of wireless transmission technology, and in particular to a wireless power transmission device. Background Art

[0002] Wireless power transmission devices can wirelessly supply power to electrical devices within a certain distance. Compared with traditional wired charging, wireless power transmission devices get rid of the traditional electrical connection between the transmitter and the receiver, overcoming the defects of equipment wear, electric shock, sparks, etc. caused by the existing contact power transmission method. In recent years, new wireless power transmission technologies have been widely used in military, aviation, medical, and civilian electrical appliances. However, the magnetic field diverges severely during long-distance transmission, resulting in reduced transmission efficiency, which limits the promotion and application of wireless power transmission. Summary of the invention

[0003] The present invention provides a wireless power transmission device, which realizes magnetic field focusing, enhances the coupling effect between a transmitting coil and a receiving coil, improves the transmission magnetic field strength, and reduces the influence of the transmission distance.

[0004] An embodiment of the present invention provides a wireless power transmission device, comprising: a transmitting coil, a magnetically negative metamaterial plate, and a receiving coil;

[0005] The magnetic negative metamaterial plate is arranged on one side of the transmitting coil, and the receiving coil is arranged on the side of the magnetic negative metamaterial plate away from the transmitting coil;

[0006] The magnetic negative metamaterial plate includes n×n resonant elements arranged in a matrix, and the resonant elements include a substrate and a planar coil wound by a conductive wire; the planar coil is laid on the surface of the substrate; and the shape of the planar coil is a regular pattern.

[0007] Optionally, the wireless power transmission device further includes a capacitor unit; one end of the planar coil is connected to the first pole of the capacitor unit, and the other end of the planar coil is connected to the second pole of the capacitor unit.

[0008] Optionally, the transmitting coil, the magnetically negative metamaterial plate and the receiving coil are coaxially and parallelly arranged.

[0009] Optionally, the ratio of the diameter of the receiving coil to the side length of the magnetically negative metamaterial plate in the first direction is in the range of 0.5-1.5;

[0010] The ratio of the diameter of the transmitting coil to the side length of the magnetically negative metamaterial plate in the first direction is in the range of 0.5-1.5.

[0011] Optionally, the wireless power transmission device further includes a shielding structure; one of the shielding structures is disposed on a side of the transmitting coil away from the magnetically negative metamaterial plate, and the other of the shielding structures is disposed on a side of the receiving coil away from the magnetically negative metamaterial plate.

[0012] Optionally, the shielding structure includes a ferrite substrate, a nanocrystalline magnetic core, and a plurality of nanocrystalline alloy structures;

[0013] The nanocrystalline magnetic core is arranged at the center of the ferrite substrate; wherein the ferrite substrate is provided with hollow areas at equal intervals around the nanocrystalline magnetic core; the hollow areas are used to accommodate the nanocrystalline alloy structure.

[0014] Optionally, the orthographic projection of the crystalline alloy structure on the ferrite substrate at least partially covers the orthographic projections of the transmitting coil and the receiving coil on the ferrite substrate.

[0015] Optionally, the ferrite substrate is a circular substrate, and a diameter of the circular substrate is greater than or equal to an outer diameter of the transmitting coil and the receiving coil.

[0016] Optionally, the interval angle is 30°.

[0017] Optionally, the nanocrystalline alloy structure includes a first strip-shaped nanocrystalline alloy and a second strip-shaped nanocrystalline alloy;

[0018] The first strip-shaped nanocrystalline alloy extends outward with the nanocrystalline magnetic core as an end point, the second strip-shaped nanocrystalline alloy is vertically connected to the first strip-shaped nanocrystalline alloy, and the length of the first strip-shaped nanocrystalline alloy is greater than the length of the second strip-shaped nanocrystalline alloy.

[0019] The wireless power transmission device provided by the embodiment of the present invention is achieved by arranging a magnetic negative metamaterial plate between a transmitting coil and a receiving coil of wireless transmission, wherein the magnetic negative metamaterial plate includes n×n resonant elements arranged in a matrix, the resonant elements include a substrate and a planar coil wound by a conductive wire; the planar coil is laid on the surface of the substrate; the shape of the planar coil is a regular pattern, and the resonant elements are used to make the magnetic negative metamaterial plate have magnetic negative metamaterial characteristics, change the magnetic field distribution in the transmission process, thereby optimizing the magnetic field distribution, so that the energy emitted by the transmitting coil is more coupled to the receiving coil, realize magnetic field focusing, enhance the coupling effect between the transmitting coil and the receiving coil, improve the transmission magnetic field strength, and reduce the influence of the transmission distance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of the structure of a wireless power transmission device provided by an embodiment of the present invention;

[0021] Figure 2A schematic diagram of the structure of a resonant element provided by an embodiment of the present invention;

[0022] Figure 3 A schematic structural diagram of a shielding structure provided by an embodiment of the present invention from a first viewing angle;

[0023] Figure 4 for Figure 3 A schematic structural diagram of a shielding structure from a second viewing angle;

[0024] Figure 5 This is the simulated magnetic field distribution cloud diagram of the unshielded structure 4 transmission system;

[0025] Figure 6 This is a cloud diagram of the simulated magnetic field distribution of the wireless power transmission device of the present invention. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] In view of the shortcomings of the prior art, in order to obtain a wireless transmission device with a longer transmission distance and higher transmission efficiency, the present invention provides a wireless power transmission device. Figure 1 A schematic diagram of a wireless power transmission device according to an embodiment of the present invention is shown in FIG. Figure 1 , comprising: a transmitting coil 1, a magnetically negative metamaterial plate 2 and a receiving coil 3;

[0028] The magnetic negative metamaterial plate 2 is arranged on one side of the transmitting coil 1, and the receiving coil 3 is arranged on the side of the magnetic negative metamaterial plate 2 away from the transmitting coil 1;

[0029] The magnetic negative metamaterial plate 2 includes n×n resonant elements arranged in a matrix, and the resonant elements include a substrate 21 and a planar coil 22 wound by a conductive wire; the planar coil 22 is laid on the surface of the substrate 21; and the shape of the planar coil 22 is a regular pattern.

[0030] Specifically, the transmitting coil 1 and receiving coil 3 of wireless transmission can be wound with conductive wires into multi-turn planar coils. Exemplarily, the winding shapes of the transmitting coil 1 and the receiving coil 3 can be regular patterns such as circles, rectangles or squares. Among them, the conductive wire can be Litz wire, which is composed of multiple strands of thin wires, and each strand of wire has an insulating layer, which can effectively reduce the AC resistance generated by the flow of current on the surface of the wire. A magnetic negative metamaterial plate 2 is arranged between the transmitting coil 1 and the receiving coil 3, wherein the magnetic negative metamaterial plate 2 includes n×n resonant elements arranged in a matrix, and the resonant element includes a substrate 21 and a multi-turn planar coil 22 wound with conductive wires on the surface of the substrate 21. Exemplarily, the conductive wire here can be a copper wire. The substrate 21 usually has heat-resistant and flame-retardant properties. The substrate 21 here can be made of a material with a flame retardant grade of FR-4. In order to facilitate matrix arrangement, the substrate 21 here can be a square. The multi-turn planar coil 22 wound on the surface of the substrate 21 can have a regular shape such as a circle, a rectangle, a square or a polygon. Exemplarily, Figure 2 A schematic diagram of a resonant element provided by an embodiment of the present invention is shown in FIG. Figure 2 The substrate 21 is a square, and the planar coil 22 wound on the surface of the substrate 21 is a regular octagon. The performance parameters of the inductance and capacitance of the planar coil 22 are adjusted by designing the line width, number of turns, turn spacing, line thickness, coil outer diameter and other parameters of the planar coil 22.

[0031] Therefore, the resonant frequency and magnetic permeability of the resonant element can be determined by calculation.

[0032] The formula for calculating the resonant frequency f0 of the resonant element is:

[0033]

[0034] Wherein, Ls is the inductance generated by the metal spiral of the planar coil 22, and Cs is the capacitance of the resonant element.

[0035] The equivalent magnetic permeability of the resonant element can be expressed as:

[0036]

[0037] Wherein, ω is the operating frequency, ω0 is the resonant frequency of the magnetically negative metamaterial, F is the ratio of the area of ​​the multi-turn planar coil 22 wound on the surface of the substrate 21 to the area of ​​the substrate 21, and τ is the loss parameter.

[0038] in,

[0039] Where μ0 is the magnetic permeability of vacuum, l is the spacing of the resonant element array along the magnetic field direction, ρ is the resistance per unit length of the resonant element, and r is the radius of the resonant element.

[0040] The resonant elements are arranged in an n×n matrix, and a magnetic negative metamaterial plate 2 with a magnetic permeability close to -1H / m can be constructed according to the equivalent magnetic permeability of each resonant element, so that the magnetic negative metamaterial plate 2 has magnetic negative metamaterial characteristics. This means that under the action of a magnetic field, the magnetic induction intensity of the magnetic negative metamaterial is different from the direction of the magnetic field intensity. Based on this property, the magnetic negative metamaterial has the functions of evanescent wave amplification and magnetic field focusing. This property can be used to effectively control the propagation direction of electromagnetic waves. At the same time, the magnetic negative metamaterial is used to increase the magnetic field intensity of the wireless power transmission system and improve the efficiency of wireless transmission.

[0041] The magnetic negative metamaterial plate 2 can transform the coordinates of the magnetic field near the transmitting coil 1, making it close to the receiving coil 3 in the electromagnetic space, so as to improve the efficiency of long-distance transmission. Assume that the coordinates of the transmitting coil 1 are The transformed coordinates are The geometric mapping relationship is:

[0042]

[0043] In the same coordinate system, the electromagnetic constitutive relationship can be obtained by compressing the coordinate system to the virtual coordinate system and using the Jacobian matrix for matrix transformation:

[0044]

[0045] in, is the relative permittivity in the virtual coordinate system, is the spatial magnetic permeability in the virtual coordinate system, a is the inner radius of the coil, and b is the outer radius of the coil.

[0046] The magnetic negative metamaterial plate 2 is set between the transmitting coil 1 and the receiving coil 3 of wireless transmission. Due to the electromagnetic characteristics of the magnetic negative metamaterial plate 2, there is a magnetic field focusing effect near the magnetic negative metamaterial plate 2, which enhances the coupling effect between the transmitting coil 1 and the receiving coil 3, improves the transmission magnetic field strength, and thus optimizes the magnetic field distribution.

[0047] The wireless power transmission device provided by the embodiment of the present invention is configured by arranging a magnetic negative metamaterial plate 2 between a transmitting coil 1 and a receiving coil 3 of wireless transmission, wherein the magnetic negative metamaterial plate 2 includes n×n resonant elements arranged in a matrix, the resonant element includes a substrate 21 and a planar coil 22 wound by a conductive wire; the planar coil 22 is laid on the surface of the substrate 21; the shape of the planar coil 22 is a regular pattern, and the resonant element is used to make the magnetic negative metamaterial plate 2 have magnetic negative metamaterial characteristics, change the magnetic field distribution in the transmission process, thereby optimizing the magnetic field distribution, so that the energy emitted by the transmitting coil 1 is more coupled to the receiving coil 3, realize magnetic field focusing, enhance the coupling effect between the transmitting coil 1 and the receiving coil 3, improve the transmission magnetic field strength, and reduce the influence of the transmission distance.

[0048] Optionally, the wireless power transmission device further includes a capacitor unit; one end of the planar coil 22 is connected to the first pole of the capacitor unit, and the other end of the planar coil 22 is connected to the second pole of the capacitor unit.

[0049] Specifically, the two ends of the planar coil 22 are respectively connected to the first pole and the second pole of the capacitor unit to form a series connection, that is, the capacitor unit is connected in parallel with the turn-to-turn capacitance of the planar coil 22 of the resonant element, so that the resonant element has a higher total capacitance value and reduces the resonant frequency. By calculating and determining the total capacitance value, the magnetic permeability of the resonant element can be close to -1H / m.

[0050] Optional, continue to see Figure 1 The transmitting coil 1, the magnetic negative metamaterial plate 2 and the receiving coil 3 are coaxially and parallelly arranged. The magnetic negative metamaterial plate 2 is parallelly arranged between the transmitting coil 1 and the receiving coil 3 of wireless transmission. The magnetic negative metamaterial plate 2 is coaxially arranged with the transmitting coil 1 and the receiving coil 3, that is, the centers of the transmitting coil 1, the magnetic negative metamaterial plate 2 and the receiving coil 3 are on the same straight line, which can improve the magnetic focusing effect of the magnetic negative metamaterial plate 2 and enhance the coupling effect between the transmitting coil 1 and the receiving coil 3.

[0051] Optionally, in order to further improve the magnetic focusing effect of the magnetic negative metamaterial plate 2, the side length of the magnetic negative metamaterial plate 2 composed of n×n matrix-arranged resonant elements should be approximately equal to the diameter of the receiving coil 3 and the diameter of the transmitting coil 1, so that the magnetic negative metamaterial plate 2 can at least partially cover the enclosed area of ​​the receiving coil 3 and the transmitting coil 1 in the coaxial projection direction. In the embodiment of the present invention, the ratio of the diameter of the receiving coil 3 to the side length of the magnetic negative metamaterial plate 2 in the first direction is limited to 0.5-1.5; and the ratio of the diameter of the transmitting coil 1 to the side length of the magnetic negative metamaterial plate 2 in the first direction is limited to 0.5-1.5. When the side length of the matrix arrangement and the diameter of the transmitting coil 1 and the receiving coil 3 are in a certain ratio range, it can be considered that the side length of the magnetic negative metamaterial plate 2 is approximately equal to the diameter of the receiving coil 3 and the diameter of the transmitting coil 1.

[0052] Continue to see Figure 1 Optionally, the wireless power transmission device further includes a shielding structure 4; one shielding structure 4 is arranged on the side of the transmitting coil 1 away from the magnetic negative metamaterial plate 2, and the other shielding structure 4 is arranged on the side of the receiving coil 3 away from the magnetic negative metamaterial plate 2.

[0053] Specifically, a shielding structure 4 is respectively provided on one side of the transmitting coil 1 and the receiving coil 3 away from the magnetic negative metamaterial plate 2 , and the shielding structure 4 is used to further enhance and converge the magnetic field and reduce magnetic field leakage.

[0054] Optional, Figure 3A schematic structural diagram of a shielding structure provided by an embodiment of the present invention from a first viewing angle, Figure 4 for Figure 3 A schematic diagram of the shielding structure from a second perspective, combined with Figure 1 , see Figure 3 and Figure 4 , the shielding structure 4 includes a ferrite substrate 41, a nanocrystalline magnetic core 42 and a plurality of nanocrystalline alloy structures 43;

[0055] The nanocrystalline magnetic core 42 is disposed at the center of the ferrite substrate 41 ; wherein the ferrite substrate 41 is provided with hollow areas at equal intervals around the nanocrystalline magnetic core 42 ; the hollow areas are used to accommodate the nanocrystalline alloy structure 43 .

[0056] Specifically, the nanocrystalline magnetic core 42 is arranged at the center of the ferrite substrate 41, and hollow areas are arranged at equal intervals around the nanocrystalline magnetic core 42, and the nanocrystalline alloy structures 43 are assembled in the hollow areas to form a plane on the ferrite substrate 41. Exemplarily, the interval angle can be allocated according to the number of nanocrystalline alloy structures 43, and in the embodiment of the present invention, the interval angle can be 30°, so eight groups of nanocrystalline alloy structures 43 can be arranged around the nanocrystalline magnetic core 42.

[0057] The material of the nanocrystalline alloy structure 43 is nanocrystalline alloy material, which mainly refers to materials with a mixed organizational structure of nano-scale microcrystals and amorphous materials, and has high strength, high hardness, thermal stability and excellent magnetic properties, as well as higher saturation magnetic induction intensity and lower magnetic loss. These characteristics enable the nanocrystalline alloy material to reduce eddy current losses during transmission and improve transmission efficiency under the same transmission power; its excellent thermal stability and magnetic properties can maintain stable magnetic field distribution and temperature control during wireless transmission, ensuring the safety of wireless power transmission. The shape of the orthographic projection of the nanocrystalline alloy structure 43 on the ferrite substrate 41 can be a regular shape, wherein the orthographic projection of the nanocrystalline alloy structure 43 on the ferrite substrate 41 at least partially covers the orthographic projection of the transmitting coil 1 on the ferrite substrate 41, and the orthographic projection of the nanocrystalline alloy structure 43 on the ferrite substrate 41 at least partially covers the orthographic projection of the receiving coil 3 on the ferrite substrate 41, that is, the area enclosed by the nanocrystalline alloy structure 43 on one side of the transmitting coil 1 can cover the transmitting coil 1, and the area enclosed by the nanocrystalline alloy structure 43 on one side of the receiving coil 3 can cover the receiving coil 3, thereby improving the shielding effect of the shielding structure 4 of each of the transmitting coil 1 and the receiving coil 3.

[0058] Optionally, the ferrite substrate 41 may be a circular substrate, and the diameter of the circular substrate is greater than or equal to the outer diameters of the transmitting coil 1 and the receiving coil 3. The ferrite substrate 41 may cover the transmitting coil 1 and the receiving coil 3 accordingly.

[0059] Optionally, the nanocrystalline alloy structure 43 includes a first strip of nanocrystalline alloy 431 and a second strip of nanocrystalline alloy 432; the first strip of nanocrystalline alloy 431 extends outward with the nanocrystalline magnetic core 42 as an endpoint, and the second strip of nanocrystalline alloy 432 is vertically connected to the first strip of nanocrystalline alloy 431, and the length dimension of the first strip of nanocrystalline alloy 431 is greater than the length dimension of the second strip of nanocrystalline alloy 432.

[0060] Specifically, the second strip-shaped nanocrystalline alloy 432 is vertically connected to the first strip-shaped nanocrystalline alloy 431, that is, the second strip-shaped nanocrystalline alloy 432 and the first strip-shaped nanocrystalline alloy 431 are in a "T"-shaped structure, with the nanocrystalline magnetic core 42 as the center, the ferrite substrate 41 is circular, and the end of the first strip-shaped nanocrystalline alloy 431 away from the second strip-shaped nanocrystalline alloy 432 is arranged close to the nanocrystalline magnetic core 42, and the "T"-shaped structure is arranged at equal intervals around the nanocrystalline magnetic core 42. For example, the interval angle can be 30°, which can reduce the amount of nanocrystalline alloy used and also meet the shielding effect of the shielding structure 4. The shielding structure 4 composed of ferrite material and nanocrystalline alloy material can greatly converge the magnetic field to the vicinity of the transmitting or receiving coil 3, effectively converge and shield the magnetic field, reduce the leakage of the magnetic field, and improve the coupling coefficient between the transmitting coil 1 and the receiving coil 3.

[0061] Based on the above embodiments, the present invention provides a wireless power transmission device, Figure 1 In the embodiment, the transmitting coil 1 and the receiving coil 3 of the wireless transmission are wound by Litz wire into a circular planar coil 22, with an inner radius of 100mm, 5 turns, and a turn spacing of 3mm. The substrate 21 of the resonant element has a side length of 35mm and a thickness of 0.5mm; the copper wire used has a line width of 0.3mm, a turn spacing of 0.3mm, a thickness of 0.04mm, an outer diameter of 30mm, and 6 turns, which is laid flat on the surface of the substrate 21 to form a regular octagonal planar coil 22. The two ends of the planar coil 22 are connected in series with the capacitor unit, which can be regarded as being connected in parallel with the turn-to-turn capacitance of the planar coil 22 of the resonant element, so that the resonant element has a higher total capacitance value, reduces the resonant frequency, and makes its magnetic permeability μ close to -1H / m.

[0062] The side length of the n×n matrix arrangement is determined according to the size of the transmitting coil 1 and the receiving coil 3. In this embodiment, the diameter of the transmitting coil 1 and the receiving coil 3 is 100 mm, so a matrix arrangement of 2×2 resonant elements is set to form a magnetic negative metamaterial plate 2 with a side length of 70 mm and a magnetic permeability of about -1H / m. The shielding structure 4 includes 8 "T"-shaped nanocrystalline alloys, a nanocrystalline magnetic core 42, and a ferrite substrate 41, wherein the ferrite substrate 41 is a circular substrate.

[0063] In this example, the transmitting coil 1, the receiving coil 3, and the magnetic negative metamaterial plate 2 are coaxially and parallelly arranged, the vertical distance between the transmitting coil 1 and the receiving coil 3 is 300 mm, the magnetic negative metamaterial plate 2 is arranged between the transmitting coil 1 and the receiving coil 3, and the vertical distance between the magnetic negative metamaterial plate 2 and the transmitting coil 1 is 60 mm. Finite element electromagnetic field simulation software is used for simulation analysis.

[0064] Among them, under the same structure, two situations are set up respectively, namely, a non-shielding structure 4, a ferrite shielding plate only, and a common magnetic core structure for comparison, and the self-inductance, mutual inductance, and coupling coefficient of each structure are calculated. Table 1 shows the simulation data of different structures. Compared with the commonly used non-shielding structure 4, the mutual inductance of the magnetic negative metamaterial and the composite shielding structure 4 provided by the present invention is doubled, and the coupling coefficient is increased by about 0.003123.

[0065] Table 1 Simulation data of different structures

[0066]

[0067] Based on the unshielded structure 4 and the combined structure of the magnetically negative metamaterial plate 2 and the shielded structure 4 of the present invention, an analysis is performed, and an axial section passing through the transmitting coil 1 and the receiving coil 3, namely the YOZ plane in the figure, is selected as a reference plane to draw a magnetic field distribution cloud map. Figure 5 This is the simulated magnetic field distribution cloud diagram of the unshielded structure 4 transmission system. Figure 6 To simulate the magnetic field distribution cloud map of the wireless power transmission device of the present invention, Figure 5 and Figure 6 It can be seen from the comparison that due to the electromagnetic characteristics of the magnetic negative metamaterial plate 2, there is a magnetic focusing effect near the magnetic negative metamaterial plate 2, which enhances the coupling effect between the transmitting coil 1 and the receiving coil 3, and improves the transmission magnetic field strength. At the same time, under the action of the shielding structure 4, the magnetic field converges to the center of the coil, the leakage magnetic field outside the coil is reduced, and the transmission efficiency of the system is improved.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wireless power transmission device, characterized in that: include: Transmitting coil, magnetically negative metamaterial plate and receiving coil; The magnetic negative metamaterial plate is arranged on one side of the transmitting coil, and the receiving coil is arranged on the side of the magnetic negative metamaterial plate away from the transmitting coil; The magnetic negative metamaterial plate includes n×n resonant elements arranged in a matrix, and the resonant elements include a substrate and a planar coil wound by a conductive wire; the planar coil is laid on the surface of the substrate; and the shape of the planar coil is a regular pattern.

2. The wireless power transmission device according to claim 1, characterized in that: It also includes a capacitor unit; one end of the planar coil is connected to the first pole of the capacitor unit, and the other end of the planar coil is connected to the second pole of the capacitor unit.

3. The wireless power transmission device according to claim 1, characterized in that: The transmitting coil, the magnetically negative metamaterial plate and the receiving coil are coaxially and parallelly arranged.

4. The wireless power transmission device according to claim 3, characterized in that: The ratio of the diameter of the receiving coil to the side length of the magnetically negative metamaterial plate in the first direction is in the range of 0.5-1.5; The ratio of the diameter of the transmitting coil to the side length of the magnetically negative metamaterial plate in the first direction is in the range of 0.5-1.

5.

5. The wireless power transmission device according to any one of claims 1 to 4, characterized in that: It also includes a shielding structure; one of the shielding structures is arranged on the side of the transmitting coil away from the magnetic negative metamaterial plate, and the other shielding structure is arranged on the side of the receiving coil away from the magnetic negative metamaterial plate.

6. The wireless power transmission device according to claim 5, characterized in that: The shielding structure includes a ferrite substrate, a nanocrystalline magnetic core, and a plurality of nanocrystalline alloy structures; The nanocrystalline magnetic core is arranged at the center of the ferrite substrate; wherein the ferrite substrate is provided with hollow areas at equal intervals around the nanocrystalline magnetic core; the hollow areas are used to accommodate the nanocrystalline alloy structure.

7. The wireless power transmission device according to claim 6, characterized in that: The orthographic projection of the crystal alloy structure on the ferrite substrate at least partially covers the orthographic projections of the transmitting coil and the receiving coil on the ferrite substrate.

8. The wireless power transmission device according to claim 7, characterized in that: The ferrite substrate is a circular substrate, and a diameter of the circular substrate is greater than or equal to an outer diameter of the transmitting coil and the receiving coil.

9. The wireless power transmission device according to any one of claims 6 to 8, characterized in that: The interval angle is 30°.

10. The wireless power transmission device according to claim 7, characterized in that: The nanocrystalline alloy structure includes a first strip-shaped nanocrystalline alloy and a second strip-shaped nanocrystalline alloy; The first strip-shaped nanocrystalline alloy extends outward with the nanocrystalline magnetic core as an end point, the second strip-shaped nanocrystalline alloy is vertically connected to the first strip-shaped nanocrystalline alloy, and the length of the first strip-shaped nanocrystalline alloy is greater than the length of the second strip-shaped nanocrystalline alloy.

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