A highly robust magnetic resonance wireless energy transfer system based on symmetrically distributed transmit arrays

Abstract

The application discloses a kind of high robustness magnetic resonance wireless energy transmission systems based on symmetrical distributed transmitting array, it is related to wireless energy transmission technical field, including: source coil array, transmitting coil array, receiving coil array and dielectric substrate;Dielectric substrate includes three layers, source coil array, transmitting coil array and receiving coil array are printed on three layers dielectric substrate respectively.The application utilizes the multi-layer arrangement of source coil array inside and outside nesting, it is helpful to maximize magnetic resonance coupling and the magnetic field focusing in the direction, enhance magnetic field intensity, the dense arrangement of coil in transmitting coil array obtains large range uniform stable magnetic field, and each coil is increased resonance capacitor, ensure that each sub-coil can be in working frequency resonance, more convenient and receiving coil coupling, further enhance transmission efficiency.The proposed technology for improving the robustness of magnetic resonance wireless energy transmission has good effect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wireless energy transmission, and in particular to a high-robustness magnetic resonance wireless energy transmission system based on a symmetric distributed transmitting array. BACKGROUND

[0002] In recent years, wireless energy transmission has attracted widespread attention. Magnetic resonance wireless energy transmission uses resonance coupling between coils to transmit energy, which can provide high power transmission efficiency at medium and long distances. At the same time, due to its advantages such as high portability, safety and low cost, it is widely used in portable electronic products, implantable medical devices, electric vehicles, robot systems and energy harvesting devices. However, the transmission efficiency of traditional MCR-WPT systems can be significantly reduced due to the angular or lateral offset of the transmitting coil and the receiving coil. Traditional single rectangular / circular coils and dipole coils can only provide high efficiency within a limited range and cannot maintain high transmission efficiency over a large range. When the transmitting coil and the receiving coil are offset, the transmission efficiency will be greatly reduced. Therefore, the wireless energy transmission system needs a method that can resist distance changes and lateral offsets. In summary, it is important to study a method that can improve the robustness of the wireless energy transmission system.

[0003] To solve the above problems, researchers have proposed many solutions. Some researchers propose using a switched transmitting array composed of four rectangular coils distributed at the four corners. When the receiving coil is offset to the corresponding area, the corresponding rectangular coil will be turned on to enhance the transmission power. Other researchers propose using a circuit compensation topology. By using a non-resonant compensation method, the compensation parameters of the relay coil and the receiving coil are optimized to reduce losses and improve efficiency. However, the above existing designs have the problems of large size and complex circuit topology, making the system more sensitive to parameter changes and difficult to implement. Therefore, a technology for improving the robustness of magnetic resonance wireless energy transmission is proposed. SUMMARY

[0004] The technical problem to be solved by the present application is to propose a technology suitable for improving the robustness of a magnetic resonance wireless energy transmission system to reduce the decrease in transmission efficiency when the transmitting part and the receiving end are offset.

[0005] To achieve the above-mentioned purpose, the present application provides a high-robustness magnetic resonance wireless energy transmission system based on a symmetric distributed transmitting array, comprising: a source coil array, a transmitting coil array, a receiving coil array and a dielectric substrate; the dielectric substrate comprises three layers, and the source coil array, the transmitting coil array and the receiving coil array are respectively printed on the three layers of the dielectric substrate.

[0006] Preferably, the source coil array is printed on the first layer of the medium substrate; the transmitting coil array is printed on the second layer of the medium substrate; the source coil array and the transmitting coil array are closely superimposed together to form a transmitting end; the source coil array transmits energy to the transmitting coil array through coupling.

[0007] Preferably, the source coil array is composed of three layers of coils nested inside and outside, and the three layers of coils of different types are used for magnetic field concentration and impedance matching through reverse winding.

[0008] Preferably, the transmitting coil array is composed of eight four-turn triangular coils arranged around the center in a rotating manner, and a high-strength, wide-range stable magnetic field is formed through the close arrangement of the coils.

[0009] Preferably, the source coil array is composed of a first winding, a second winding, a third winding, a fourth winding and a first capacitor; one end of the first winding is used for welding an SMA interface, and the other end is connected to the second winding; the second winding is a single-turn rectangular coil, which is located at the outermost layer of the source coil array, one end of the second winding is connected to the first winding, and the other end is connected to the third winding, and at the same time, the first capacitor is connected to the middle of the first winding through reverse winding; the third winding is a single-turn rectangular coil, which is located between the second winding and the fourth winding, one end of the third winding is connected to the second winding, and the other end is connected to the fourth winding, and the internal current direction is opposite to that of the second winding; the fourth winding is a single-turn circular coil, which is located at the center of the array, and the internal current direction is opposite to that of the third winding, both ends of the fourth winding are connected to the third winding to form a closed loop; the first capacitor is welded at the middle interval position of the second winding, and both ends of the first capacitor are connected to the second winding to be added to the closed loop.

[0010] Preferably, the transmitting coil array is composed of a first resonant unit, a second resonant unit, a third resonant unit, a fourth resonant unit, a fifth resonant unit, a sixth resonant unit, a seventh resonant unit, an eighth resonant unit printed on the front of the second layer of the medium substrate, and a second resonant capacitor, a third resonant capacitor, a fourth resonant capacitor, a fifth resonant capacitor, a sixth resonant capacitor, a seventh resonant capacitor, an eighth resonant capacitor, a ninth resonant capacitor printed on the back of the second layer of the medium substrate; the first resonant unit is connected to the second resonant capacitor through a metal via; the second resonant unit is connected to the third resonant capacitor through a metal via; the third resonant unit is connected to the fourth resonant capacitor through a metal via; the fourth resonant unit is connected to the fifth resonant capacitor through a metal via; the fifth resonant unit is connected to the sixth resonant capacitor through a metal via; the sixth resonant unit is connected to the seventh resonant capacitor through a metal via; the seventh resonant unit is connected to the eighth resonant capacitor through a metal via; the eighth resonant unit is connected to the ninth resonant capacitor through a metal via; the resonant units are not in contact with each other and are arranged around the center.

[0011] Preferably, the receiving coil array includes a receiving coil and a load coil, which are printed on the third layer of the medium substrate to form a receiving end.

[0012] Compared with the prior art, the application has the following advantages:

[0013] The application utilizes the multi-layer arrangement of the nested source coil array, which helps to maximize the magnetic resonance coupling and the magnetic field focusing in the direction, enhances the magnetic field strength, and the dense arrangement of the coils in the transmitting coil array obtains a large range of uniform and stable magnetic field, and each coil increases the resonant capacitor, which ensures that each sub-coil can resonate at the working frequency and further enhances the transmission efficiency. The proposed technology for improving the robustness of magnetic resonance wireless energy transmission has good effect. BRIEF DESCRIPTION OF DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the application, the following briefly introduces the drawings needed in the embodiments. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0015] Figure 1 is the overall structure of the technology for improving the robustness of the magnetic resonance wireless energy transmission system of the embodiment of the application;

[0016] Figure 2 is the source coil array structure of the embodiment of the application;

[0017] Figure 3 This is a structural diagram of the transmitting coil array according to an embodiment of the present invention;

[0018] Figure 4 This is a structural diagram of the receiving end according to an embodiment of the present invention;

[0019] Figure 5 This is a graph of the S-parameters of the wireless power transmission system in an embodiment of the present invention.

[0020] Figure 6 This is a graph showing the transmission efficiency of the wireless power transmission system in this embodiment of the invention as a function of offset distance.

[0021] Explanation of reference numerals in the attached diagram: 1. First winding; 2. Second winding; 3. Third winding; 4. Fourth winding; 5. First capacitor; 6. First resonant unit; 7. Second resonant unit; 8. Third resonant unit; 9. Fourth resonant unit; 10. Fifth resonant unit; 11. Sixth resonant unit; 12. Seventh resonant unit; 13. Eighth resonant unit; 14. Second resonant capacitor; 15. Third resonant capacitor; 16. Fourth resonant capacitor; 17. Fifth resonant capacitor; 18. Sixth resonant capacitor; 19. Seventh resonant capacitor; 20. Eighth resonant capacitor; 21. Ninth resonant capacitor; 22. Receiving coil; 23. Tenth resonant capacitor; 24. Fifth winding; 25. Sixth winding. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] Example 1:

[0025] like Figure 1As shown, the high-robustness magnetic resonance wireless energy transmission system based on symmetric distributed transmitting array provided by the embodiment of the application comprises a source coil array, a transmitting coil array, a receiving coil array and a dielectric substrate. The source coil array is printed on the back of a first layer of dielectric substrate, the transmitting coil array is printed on the back of a second layer of dielectric substrate, the front of the first layer of dielectric substrate and the back of the second layer of dielectric substrate are in contact with each other and are stacked together, the receiving coil array is printed on the back of a third layer of dielectric substrate and is separated from the second layer of dielectric substrate by a certain distance. The source coil array is composed of two layers of rectangular coils and one layer of circular coil which are nested with each other. The current directions of the coils of the adjacent two layers are opposite, which helps to maximize the magnetic resonance coupling and the magnetic field focusing in the direction, and the energy is transmitted to the transmitting coil array through coupling.

[0026] Further, the transmitting end is composed of the source coil array and the transmitting coil array. The source coil array and the transmitting coil array are respectively printed on two layers of dielectric substrates. The source coil array is printed on the back of a first layer of dielectric substrate, and the transmitting coil array is printed on the back of a second layer of dielectric substrate. The front is printed with a connecting wire and a resonance capacitor. The front of the first layer of dielectric substrate and the back of the second layer of dielectric substrate are stacked together, which facilitates the coupling of the source coil array and the transmitting coil array.

[0027] Further, as shown, Figure 2 The source coil array is printed on the first layer of dielectric substrate and is composed of a first winding 1, a second winding 2, a third winding 3, a fourth winding 4 and a first capacitor 5. One end of the first winding 1 is used for welding an SMA interface, and the other end is connected to the second winding 2. The second winding 2 is a single-turn rectangular coil, which is in the outermost layer of the array, one end of which is connected to the first winding 1, and the other end is connected to the third winding 3. At the same time, a first capacitor 5 is connected in the middle of the first winding 1 by means of reverse winding. The third winding 3 is a single-turn rectangular coil, which is in the middle of the second winding 2 and the fourth winding 4, one end of which is connected to the second winding 2, and the other end is connected to the third winding 3. The internal current direction is opposite to that of the second winding 2. The fourth winding 4 is a single-turn circular coil, which is in the center position of the array. The internal current direction is opposite to that of the third winding 3, and both ends are connected to the third winding 3 to form a closed loop. The first capacitor 5 is welded at the middle interval position of the second winding 2, and both ends are connected to the second winding 2 to be added to the closed loop, so that the source coil array resonates at the working frequency. This nested arrangement helps to maximize the magnetic resonance coupling and the magnetic field focusing in the direction, further enhancing the magnetic field strength. The gap between the rectangular coils obtains a parasitic capacitor which helps to match the impedance and ensure the stability of the magnetic field.

[0028] Further, as shown,Figure 3 As shown, the transmitting coil array is printed on the second layer of medium substrate, which is composed of the first resonant unit 6, the second resonant unit 7, the third resonant unit 8, the fourth resonant unit 9, the fifth resonant unit 10, the sixth resonant unit 11, the seventh resonant unit 12, the eighth resonant unit 13, the second resonant capacitor 14, the third resonant capacitor 15, the fourth resonant capacitor 16, the fifth resonant capacitor 17, the sixth resonant capacitor 18, the seventh resonant capacitor 19, the eighth resonant capacitor 20, and the ninth resonant capacitor 21; wherein the first resonant unit 6 is connected to the second resonant capacitor 14 on the back surface through a metal via; the second resonant unit 7 is connected to the third resonant capacitor 15 on the back surface through a metal via; the third resonant unit 8 is connected to the fourth resonant capacitor 16 on the back surface through a metal via; the fourth resonant unit 9 is connected to the fifth resonant capacitor 17 on the back surface through a metal via; the fifth resonant unit 10 is connected to the sixth resonant capacitor 18 on the back surface through a metal via; the sixth resonant unit 11 is connected to the seventh resonant capacitor 19 on the back surface through a metal via; the seventh resonant unit 12 is connected to the eighth resonant capacitor 20 on the back surface through a metal via; and the eighth resonant unit 13 is connected to the ninth resonant capacitor 21 on the back surface through a metal via. The resonant units are not in contact with each other and are arranged around the center in a rotating manner. The transmitting coil array composed of eight triangular coils can form a uniform and stable magnetic field in a wide range, and the close arrangement of the coils makes the magnetic field strength stronger, which helps to enhance the coupling with the receiving coil 22 and further enhance the transmission efficiency.

[0029] Further, the receiving coil array is composed of the receiving coil 22, the load coil, and the tenth resonant capacitor 23, which is printed on the third layer of medium substrate; wherein the receiving coil 22 is composed of a four-turn rectangular coil, which is connected to the tenth resonant capacitor 23 on the back surface through a metal via; the load coil is inside the receiving coil 22 and is composed of two windings, the fifth winding 24 and the sixth winding 25; the two ends of the fifth winding 24 and the two ends of the sixth winding 25 are connected; one end of the sixth winding 25 is connected to the fifth winding 24, and the other end is used for welding the SMA interface. The energy is transmitted to the receiving end through the coupling between the receiving coil 22 and the transmitting coil array, and then transmitted to the load coil through the coupling between the receiving coil 22 and the load coil.

[0030] Further, as shown in the figure, Figure 4 The receiving end is composed of the receiving coil array, which is printed on the back surface of the third layer of medium substrate. In use, the receiving end and the transmitting end are at a certain distance apart, with an air gap in between, and are directly opposite each other. Due to the design of the source coil array and the receiving coil array, a wide-range stable magnetic field can be formed within the range of the transmitting array, and even if the receiving end deviates during use, the transmission efficiency can still be maintained at a high level.

[0031] The high-robustness magnetic resonance wireless energy transmission system based on the symmetric distributed transmitting array in the embodiment can help to maximize the magnetic field aggregation in the direction of the magnetic resonance coupling and enhance the magnetic field strength through the source coil array composed of two rectangular coils and a circular coil nested with each other, and transmit energy to each sub-coil through the coupling with each sub-coil in the transmitting coil array. The dense arrangement of the sub-coils in the transmitting coil array enables the sub-coils to generate a uniform and stable magnetic field in a large range, which helps to couple with the receiving coil 22. Energy is transmitted to the receiving end through the coupling between the receiving coil 22 and each sub-coil in the transmitting coil array. Due to the design of the transmitting coil array, the transmission efficiency can still be maintained at a relatively stable level even if the receiving coil 22 is offset in use.

[0032] Embodiment two

[0033] The specific sizes of the coil and the dielectric substrate in the embodiment are as follows: the first layer dielectric substrate and the second layer dielectric substrate are the same in size and thickness, and have a length of 135 mm, a width of 135 mm, and a thickness of 0.5 mm; the source coil array is printed on the first layer dielectric substrate, and the copper layer has a thickness of 0.035 mm, the first winding 1 has a length of 5 mm and a width of 1 mm; the second winding 2 is a rectangular coil, has an outer diameter length of 58 mm, a width of 58 mm, and a strip width of 1.9 mm; the third winding 3 is a rectangular coil, has an outer diameter length of 51 mm, a width of 51 mm, and a strip width of 2.3 mm; the fourth winding 4 is a circular coil, has a radius of 22 mm, and a strip width of 2 mm; the transmitting coil array is printed on the second layer dielectric substrate, and the copper layer has a thickness of 0.035 mm, the eight triangular sub-coils are the same in size and are arranged in different rotating centers, the triangular coil body is an isosceles right triangle, the isosceles right triangle coil has a leg length of 60 mm, a total number of turns of five, a coil strip width of 1.52 mm, and a turn spacing of 0.95 mm, the eight sub-coils are arranged in different rotating centers and are connected to the resonant capacitor on the back through the metal through hole on the dielectric substrate; the receiving coil 22 is printed on the back of the third layer dielectric substrate, the third layer dielectric substrate has a length of 72 mm, a width of 72 mm, and a thickness of 0.5 mm; the receiving coil 22 is a rectangular coil with four turns, has the same strip width and turn spacing, has an outer diameter size of 70 mm, the same length and width, a strip width of 2.1 mm, and a turn spacing of 1 mm, is wound according to the shape of the rectangle, and is connected to the resonant capacitor on the back through the metal through hole on the dielectric substrate; the load coil is a single-turn rectangular coil, and the coil is composed of two windings, the fifth winding 24 has a length of 22 mm, a width of 22 mm, and a strip width of 1.8 mm, and the sixth winding 25 has a length of 6 mm and a strip width of 1.8 mm.

[0034] The magnetic resonance wireless energy transmission system is composed of a source coil array, a transmitting coil array, a receiving coil 22 and a load coil printed on a medium plate with FR4 material. The medium plate has a thickness of 0.5 mm, a relative dielectric constant of 4.4 and a loss tangent of 0.02. The first capacitor 5 is a 10 pF capacitor of the CC0805 series produced by NXP, the second resonance capacitor 14, the third resonance capacitor 15, the fourth resonance capacitor 16, the fifth resonance capacitor 17, the sixth resonance capacitor 18, the seventh resonance capacitor 19, the eighth resonance capacitor 20 and the ninth resonance capacitor 21 are all 180 pF capacitors of the GRM2165 series produced by Murata, and the tenth resonance capacitor 23 is a 75 pF capacitor of the CC0805 series produced by NXP.

[0035] In conclusion, the application provides a high-robustness magnetic resonance wireless energy transmission system based on a symmetric distributed transmitting array, which is applied to the field of near-field wireless energy transmission. Figure 5 As shown in the figure, the wireless energy transmission system provided by the application has a return loss parameter S11 less than 10 dB at 13.56 MHz, which indicates that good impedance matching can be achieved at this frequency. Figure 6 As shown in the figure, the wireless energy transmission system provided by the application has an efficiency of 88% when the transmitting and receiving coils are completely aligned, and the efficiency can be kept at 82% when the lateral offset distance reaches 50 mm.

[0036] The above-described embodiments are only descriptions of the preferred modes of the application and do not limit the scope of the application. Without departing from the design spirit of the application, various modifications and improvements to the technical solutions of the application made by those skilled in the art shall fall within the protection scope of the claims of the application.

Claims

1. A highly robust magnetic resonant wireless power transfer system based on a symmetrical distributed transmitter array, characterized in that, include: Source coil array, transmitting coil array, receiving coil array, and dielectric substrate; The dielectric substrate comprises three layers, and the source coil array, the transmitting coil array, and the receiving coil array are respectively printed on the three layers of the dielectric substrate; The transmitting coil array consists of eight four-turn triangular coils arranged around a center, with each coil not touching the others. The close arrangement of the coils improves the robustness of the magnetic field distribution. The source coil array consists of three nested layers of coils, with different types of coils wound in opposite directions for magnetic field concentration and impedance matching. The transmitting coil array is composed of a first resonant unit, a second resonant unit, a third resonant unit, a fourth resonant unit, a fifth resonant unit, a sixth resonant unit, a seventh resonant unit, an eighth resonant unit, and a second resonant capacitor, a third resonant capacitor, a fourth resonant capacitor, a fifth resonant capacitor, a sixth resonant capacitor, a seventh resonant capacitor, an eighth resonant capacitor, and a ninth resonant capacitor. The first resonant unit is connected to the second resonant capacitor through a metal via; the second resonant unit is connected to the third resonant capacitor through a metal via; the third resonant unit is connected to the fourth resonant capacitor through a metal via; the fourth resonant unit is connected to the fifth resonant capacitor through a metal via; the fifth resonant unit is connected to the sixth resonant capacitor through a metal via; the sixth resonant unit is connected to the seventh resonant capacitor through a metal via; the seventh resonant unit is connected to the eighth resonant capacitor through a metal via; the eighth resonant unit is connected to the ninth resonant capacitor through a metal via; the first resonant unit, the second resonant unit, the third resonant unit, the fourth resonant unit, the fifth resonant unit, the sixth resonant unit, the seventh resonant unit, and the eighth resonant unit do not contact each other and are arranged in a rotating configuration around a center; The source coil array is printed on the first layer of the dielectric substrate; The transmitting coil array is printed on the second dielectric substrate; the source coil array and the transmitting coil array constitute a transmitting end; the source coil array transmits energy to the transmitting coil array through coupling; The receiving coil array includes receiving coils and load coils, which are printed on the third layer of the dielectric substrate to form a receiving end. The source coil array consists of a first winding, a second winding, a third winding, a fourth winding, and a first capacitor; One end of the first winding is used to solder an SMA connector, and the other end is connected to the second winding. The second winding is a single-turn rectangular coil located on the outermost layer of the source coil array. One end of the second winding is connected to the first winding, and the other end is connected to the third winding. Simultaneously, the first capacitor is connected in the middle of the first winding by reverse winding. The third winding is a single-turn rectangular coil located between the second winding and the fourth winding. One end of the third winding is connected to the second winding, and the other end is connected to the fourth winding. The internal current direction is opposite to that of the second winding. The fourth winding is a single-turn circular coil located at the center of the array. The internal current direction is opposite to that of the third winding. Both ends of the fourth winding are connected to the third winding to form a closed loop. The first capacitor is soldered at a mid-interval position of the second winding. The two ends of the first capacitor are respectively connected to the second winding, adding to the closed loop.

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