Wireless charging system based on spatial coupling device

Abstract

The invention provides a wireless charging system based on a spatial coupling device. The wireless charging system comprises the spatial coupling device used for resonance compensation, a receiving end rectification filter circuit and a load. The spatial coupling device inputs alternating current, the output end of the spatial coupling device is connected to the input end of the receiving end rectification filter circuit, and the output end of the receiving end rectification filter circuit is connected to a load; the spatial coupling device comprises a transmitting end resonator, a magnetic coupling device and a receiving end resonator, the output end of the transmitting end resonator is connected to the input end of the magnetic coupling device, and the output end of the magnetic coupling device is connected to the input end of the receiving end resonator. The output end of the receiving end resonator is connected with the input end of the receiving end rectification filter circuit. Through the system, the offset of the charging coil can be reduced, so that the energy transmission loss of the wireless charging system is reduced, and the charging efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of wireless charging, and in particular to a wireless charging system based on a spatial coupling device. Background Art

[0002] Wireless Power Transfer (WPT) technology, with its ability to transmit power to devices without physical connection, has greatly improved the flexibility and convenience of modern technology systems. This technology can eliminate the limitations and hidden dangers brought by plugging and unplugging of traditional cable connections, and can also realize long-distance power supply of devices in complex environments, thereby greatly enhancing the reliability and durability of equipment.

[0003] In wireless energy transmission systems, coils play a key role at the receiving and transmitting ends, directly affecting the efficiency of wireless energy transmission. When studying coils, it is necessary to consider their characteristics of high coupling coefficient and high transmission efficiency. In addition, different coil structures have different anti-deviation capabilities. At present, the research on coil coupling mechanisms for wireless energy transmission has been very in-depth, especially in the field of electric vehicles. Domestic and foreign scholars have proposed a variety of coil structures, including circular, rectangular, DD and DDQ types, etc. Among these four types of coils, the transmitting coil and the receiving coil are designed with symmetrical structures. Only when the transmitting and receiving coils are fully aligned can the highest transmission efficiency be achieved. When there is a certain distance between the transmitting coil and the receiving coil, the power transmission effect is not very ideal. The DD and DDQ structures consist of two and three coils arranged horizontally, which enhance the coupling coefficient between the coils and improve the tolerance to lateral deviation. However, if a longitudinal deviation occurs, it will seriously affect the coupling coefficient of the coil, thereby affecting the quality of wireless energy transmission.

[0004] Therefore, in order to solve the above technical problems, it is urgent to propose a new technical means. Summary of the invention

[0005] In order to achieve efficient energy transmission in a complex environment and improve the anti-deviation capability of a charging coil, the present invention proposes a wireless charging system based on a spatial coupling device.

[0006] The present invention provides a wireless charging system based on a spatial coupling device, comprising a spatial coupling device for resonance compensation, a receiving end rectifying and filtering circuit, and a load;

[0007] The spatial coupling device inputs alternating current, the output end of the spatial coupling device is connected to the input end of the receiving end rectifying and filtering circuit, and the output end of the receiving end rectifying and filtering circuit is connected to the load;

[0008] The spatial coupling device comprises a transmitting-end resonator, a magnetic coupling device and a receiving-end resonator, wherein the output end of the transmitting-end resonator is connected to the input end of the magnetic coupling device, the output end of the magnetic coupling device is connected to the input end of the receiving-end resonator, and the output end of the receiving-end resonator is connected to the input end of the receiving-end rectifying and filtering circuit;

[0009] The magnetic coupling device is composed of an emitter and a receiver, wherein the emitter is composed of m faces, m≥4, the m faces of the emitter are sequentially connected in series laterally, a concentrically connected coil is arranged in each face, and the number of turns of the coil in each face is the same, the receiver has the same structure as the emitter, the size of the receiver is smaller than the size of the emitter, and the receiver is placed in the space formed by the m faces of the emitter; the top current direction and the bottom current direction of adjacent faces of the emitter are opposite, and the top current direction of each face of the emitter is the same as the top current direction of the corresponding face of the receiver, and the bottom current direction of each face of the emitter is the same as the bottom current direction of the corresponding face of the receiver.

[0010] Furthermore, the emitter and the receiver are composed of four surfaces.

[0011] Furthermore, each surface of the radiator and the receiver and the shape of the coil wound in each surface are all isosceles trapezoids.

[0012] Furthermore, the sizes of the isosceles trapezoidal coils in the emitting body and the receiving body gradually increase from the inside to the outside.

[0013] Furthermore, when the receiving body is placed in the space of the emitting body, the receiving body and the emitting body are arranged in opposite directions; the lower bottom surface of the receiving body corresponds to the upper bottom surface of the emitting body; the lower bottom surface of the receiving body corresponds to the upper bottom surface of the emitting body.

[0014] Furthermore, the upper bottom surface of the receiving body is at least b meters higher than the lower bottom surface of the emitting body.

[0015] Furthermore, it also includes a ferrite core, and the ferrite core is arranged in the receiving body.

[0016] The beneficial effect of the present invention is that the present invention forms a transmitter by connecting m coils in series, and generates an omnidirectional magnetic field by the driving current of each coil in the transmitter on each loop segment, so that the generated magnetic field is perpendicular to each circulating loop of the coil in the receiver, so that the coils in any direction in the receiver can form a coupling system with the transmitting coil, thereby improving the anti-deviation performance of the charging coil, and further improving the charging efficiency of the wireless charging system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0018] Figure 1 Schematic diagram of the system structure of the present invention.

[0019] Figure 2 This is the principle diagram of mutual inductance between the transmitter and the receiver.

[0020] Figure 3 This is the expanded diagram of the coil winding inside the transmitter.

[0021] Figure 4 Magnetic field distribution diagram generated by the coils on the four sides of the emitter. DETAILED DESCRIPTION

[0022] The present invention is further described below in conjunction with the accompanying drawings:

[0023] The present invention provides a wireless charging system based on a spatial coupling device, comprising a spatial coupling device for resonance compensation, a receiving end rectifying and filtering circuit, and a load;

[0024] The spatial coupling device inputs alternating current, the output end of the spatial coupling device is connected to the input end of the receiving end rectifying and filtering circuit, and the output end of the receiving end rectifying and filtering circuit is connected to the load; the alternating current input to the spatial coupling device can be obtained by passing direct current through a high-frequency inverter, and the specific alternating current input to the spatial coupling device is set according to the use environment of the device, which will not be described in detail here; the rectifying and filtering circuit adopts the existing rectifying circuit and filtering circuit, which will not be described in detail here;

[0025] The spatial coupling device comprises a transmitting-end resonator, a magnetic coupling device and a receiving-end resonator, wherein the output end of the transmitting-end resonator is connected to the input end of the magnetic coupling device, the output end of the magnetic coupling device is connected to the input end of the receiving-end resonator, and the output end of the receiving-end resonator is connected to the input end of the receiving-end rectifying and filtering circuit;

[0026] The magnetic coupling device is composed of an emitter and a receiver. The emitter is composed of m faces, m≥4, and the m faces of the emitter are sequentially connected in series transversely. Figure 2 The horizontal direction in is taken as the reference, a concentrically connected coil is arranged in each plane and the number of turns of the coil in each plane is the same, the receiving body and the emitting body have the same structure, which means that the receiving body and the emitting body are formed by the same number of planes in series in the horizontal direction and each plane is also a concentrically connected coil, and the number of turns of the coils in the m planes is the same, which does not include the same number of turns of the coils of the receiving body and the emitting body; the concentrically connected coil means that a coil is wound around the same center, and the winding shape is the same and the size gradually increases or decreases;

[0027] The size of the receiver is smaller than that of the emitter and the receiver is placed in the space formed by the m faces of the emitter; the top current direction and the bottom current direction of the adjacent faces of the emitter are opposite, and the top current direction of each face of the emitter is the same as the top current direction of the corresponding face of the receiver, and the bottom current direction of each face of the emitter is the same as the bottom current direction of the corresponding face of the receiver, so that the magnetic field can be superimposed and the magnetic field strength can be increased; Figure 2 As shown in (a), when the coils on each surface are wound from the inside to the outside, the coil structures on the opposite surfaces are the same (when m is an even number); Figure 2 As shown in (b), when there are both coils wound from the inside to the outside and coils wound from the outside to the inside, the coil structure is different. The specific winding method is not limited. It is only necessary to ensure that the total number of turns is the same, and the current direction of the top and bottom of the adjacent surfaces is opposite. The bottom and top are connected by Figure 3 The directions shown are reference directions.

[0028] The coils in the transmitter and receiver in this application can be wound on a 3D printed frame so that the coils can be wound into a user-defined shape. The material of the frame should be selected to have no interference with the magnetic field. The frame is not protected by this application and will not be described in detail here.

[0029] Using a wireless charging system in a complex environment can not only prevent water from entering the interface and reduce electrical safety issues, but also improve ease of use and user experience; the wireless charging system proposed in this application can enable the coils in any direction in the receiving body to form a coupling system with the transmitting coil, thereby improving the anti-drift capability of the charging coil and thus improving the energy transmission efficiency of the charging coil.

[0030] In this embodiment, the emitter and the receiver are composed of four faces, and being set as a tetrahedron can simplify the structure as much as possible while ensuring the transmission efficiency.

[0031] In this embodiment, each face of the emitter and the receiver and the shape of the coil wound in each face are all isosceles trapezoids. Each face of the emitter and the receiver is designed to be an isosceles trapezoid. Since the waist of the trapezoid is a line segment with an inclined angle, the receiver is set in the emitter, which can limit the lateral rotation of the receiver in the emitter. The size of the isosceles trapezoid can be set according to the lateral rotation range of the receiver in the emitter limited by the user. This step can be obtained through simulation experiments, and the specific design process will not be repeated here.

[0032] In this embodiment, the size of the isosceles trapezoidal coils in the emitter and the receiver gradually increases from the inside to the outside. The emitter and the coils in the receiver are concentrically connected, such as Figure 3shown.

[0033] In this embodiment, when the receiving body is placed in the space of the emitting body, the receiving body and the emitting body are arranged in opposite directions; the lower bottom surface of the receiving body corresponds to the upper bottom surface of the emitting body; the lower bottom surface of the receiving body corresponds to the upper bottom surface of the emitting body. As long as the proportions are set appropriately, the above arrangement can prevent the receiving body from falling out of the emitting body.

[0034] In this embodiment, the upper bottom surface of the receiver is at least b meters higher than the lower bottom surface of the emitter, and b meters is the maximum longitudinal movement of the receiver in the emitter. The size of the isosceles trapezoid can be set according to the needs of the user, thereby limiting the longitudinal movement distance of the receiver in the emitter. This step can still be obtained through simulation experiments and will not be repeated here. Through the above settings, even if the receiver moves longitudinally in the emitter, it is still in the emitter, which can further improve the anti-drift performance of the device.

[0035] In this embodiment, a ferrite core is also included. The ferrite core is disposed in the receiving body, that is, in the space formed by the four surfaces of the receiving body. The connection method can be snap-fitted, and a groove can be provided for fixing. It is not described here. By increasing the ferrite core material, the durability and anti-interference ability of the device can be enhanced, ensuring that stable performance can be maintained in complex electromagnetic environments and extreme weather conditions.

[0036] In this embodiment, the wireless charging system is used in a soldier's helmet. The soldier's combat helmet is no longer just a simple protective equipment, but integrates a variety of key electronic equipment and sensors, such as communication equipment, night vision goggles, thermal imagers, etc. These devices are highly dependent on a stable power supply. Using the wireless charging system of this application in a soldier's helmet can not only ensure that these devices in the soldier's helmet can operate stably for a long time, but also avoid electrical safety issues caused by traditional charging methods.

[0037] For the convenience of carrying, the longitudinal movement of the receiving body in the transmitting body is limited to (-15,15) (unit: mm), and the lateral rotation angle is limited to -15° to 15°. The deviation within the above range can ensure that the spatial coupling device can still maintain a high coupling coefficient and good transmission performance.

[0038] After simulation calculation, the best emitter and receiver are determined to be:

[0039] The number of turns of the coil in each face of the emitter is 10, the diameter of a single turn of the coil is 2.8 mm, the upper base length of the outermost isosceles trapezoidal coil is 70 mm, the lower base length of the outermost isosceles trapezoidal coil is 92 mm, and the height is 120 mm;

[0040] The number of turns of the coil in each surface of the receiver is 5, the diameter of a single turn of the coil is 2.8mm, the upper base length of the outermost isosceles trapezoidal coil is 30mm, the lower base length of the outermost isosceles trapezoidal coil is 50mm, and the height is 60mm; and ferrite core material is added to the receiver; when ferrite is added to the receiver, the mutual inductance of the coupling mechanism is 4.699H; and without adding ferrite, the mutual inductance of the coupling mechanism is 3.957H. This shows that the ferrite core structure of the receiver is crucial to improving the efficiency of wireless charging; the use of ferrite core material can enhance the durability and anti-interference ability of the coupling mechanism, ensuring that the helmet can still maintain stable performance in complex electromagnetic environments and extreme weather conditions;

[0041] The size and position of each trapezoidal coil are precisely calculated to ensure the effectiveness and stability during electromagnetic field transmission and coupling. The advantage of this structural design is that it can achieve uniform magnetic field distribution and efficient energy transmission, which is suitable for various wireless energy transmission systems and application scenarios. Figure 4 (a), (b), (c) and (d) respectively show the magnetic field distribution generated by the coils on the four sides of the emitter. It can be seen that the emitter can generate a complex three-dimensional magnetic field. Although the air gaps between the coils are also shown, these air gaps will cause the magnetic field intensity near the air gaps to be lower; but the four coils are staggered on the four sides, and the air gap position of each coil is different. The four sides are connected in series horizontally, so that there is only one air gap on each side, which can make the magnetic field distribution more uniform, especially outside the air gap, the magnetic field decays more slowly.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A wireless charging system based on a spatial coupling device, characterized in that: It includes a spatial coupling device for resonance compensation, a receiving end rectification and filtering circuit and a load; The spatial coupling device inputs alternating current, the output end of the spatial coupling device is connected to the input end of the receiving end rectifying and filtering circuit, and the output end of the receiving end rectifying and filtering circuit is connected to the load; The spatial coupling device comprises a transmitting-end resonator, a magnetic coupling device and a receiving-end resonator, wherein the output end of the transmitting-end resonator is connected to the input end of the magnetic coupling device, the output end of the magnetic coupling device is connected to the input end of the receiving-end resonator, and the output end of the receiving-end resonator is connected to the input end of the receiving-end rectifying and filtering circuit; The magnetic coupling device is composed of an emitter and a receiver, wherein the emitter is composed of m faces, m≥4, the m faces of the emitter are sequentially connected in series laterally, a concentrically connected coil is arranged in each face, and the number of turns of the coil in each face is the same, the receiver has the same structure as the emitter, the size of the receiver is smaller than the size of the emitter, and the receiver is placed in the space formed by the m faces of the emitter; the top current direction and the bottom current direction of adjacent faces of the emitter are opposite, and the top current direction of each face of the emitter is the same as the top current direction of the corresponding face of the receiver, and the bottom current direction of each face of the emitter is the same as the bottom current direction of the corresponding face of the receiver.

2. The wireless charging system based on the spatial coupling device according to claim 1, characterized in that: The emitter and the receiver are composed of four surfaces.

3. The wireless charging system based on the spatial coupling device according to any one of claims 1 or 2, characterized in that: Each surface of the radiator and the receiver and the shape of the coil wound in each surface are all isosceles trapezoids.

4. The wireless charging system based on the spatial coupling device according to claim 3, characterized in that: The sizes of the isosceles trapezoidal coils in the emitting body and the receiving body gradually increase from the inside to the outside.

5. The wireless charging system based on the spatial coupling device according to claim 3, characterized in that: When the receiving body is placed in the space of the emitting body, the receiving body and the emitting body are arranged in opposite directions; the lower bottom surface of the receiving body corresponds to the upper bottom surface of the emitting body; the lower bottom surface of the receiving body corresponds to the upper bottom surface of the emitting body.

6. The wireless charging system based on the spatial coupling device according to claim 5, characterized in that: The upper bottom surface of the receiving body is at least b meters higher than the lower bottom surface of the emitting body.

7. The wireless charging system based on the spatial coupling device according to claim 6, characterized in that: It also includes a ferrite core, which is arranged in the receiving body.

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