Lantern type transmitting coil for wireless power transmission

Abstract

The invention discloses a lantern-shaped transmitting coil for wireless electric energy transmission, belongs to the technical field of electronic information, and more importantly, when the transmission distance is 15mm-25mm, the energy transmission efficiency of a system even can be kept at 60% or above, and when the deviation range in the horizontal direction is-30mm-20mm, the stable energy transmission efficiency can be kept at 60% or above. And finally, when the transmission distance between the transmitting coil and the receiving coil is fixed to be 10mm, angle deviation occurs and the rotation angle is within the range of-15 degrees to 15 degrees, the transmission of the coils is kept to be more than 65%, the numerical values and the number of compensation capacitors and inductors for impedance matching can be adjusted according to actual requirements, and the impedance matching precision is improved. The working frequency of the coil is flexibly adjusted or the performance of the coil is optimized, the shapes of the transmitting coil and the receiving coil can be modified to a certain extent according to actual requirements or aesthetic requirements, and the coil is made of the most common materials, so that higher power transmission efficiency can be realized at lower cost.

Description

Technical Field

[0001] The invention relates to a lantern-shaped transmitting coil for wireless power transmission, in particular to wireless power transmission, and belongs to the field of electronic information technology. Background Art

[0002] In recent years, wireless power transmission (WPT) has attracted the attention of many researchers and engineers because it can get rid of the constraints of wired transmission. It also provides a potential solution for power supply. According to the principle of power transmission, WPT can be divided into different modes, including inductive coupling, microwave radiation, and magnetic coupling resonance. The most commonly used wireless charging method in existing research is magnetic coupling resonance. Magnetic coupling resonance is a solution that uses magnetic coupling to make the transmitting coil and the receiving coil resonate at a specific frequency, thereby achieving wireless power transmission.

[0003] When the transmitting and receiving coils are well matched, this transmission method can provide more efficient power transmission at a longer distance in the megahertz band. In addition, magnetic coupling resonance uses magnetic field coupling and non-radiation technology, which has good penetration while greatly reducing harm to the human body. Magnetic coupling resonance transmission technology has higher reliability, safety and convenience, and has been widely studied and applied in transportation, portable electronic devices, implantable medical devices and other fields.

[0004] At present, the couplers used to study the performance of magnetically coupled resonant WPT systems usually use simple two-dimensional coupling coils. However, the two-dimensional coils are limited by their planar layout. If the receiver moves in the horizontal and vertical directions or rotates at an angle, there will be a misalignment state, resulting in a rapid decrease in efficiency or even failure to work.

[0005] Designing a high-performance coupling coil is one of the most important conditions affecting the transmission performance of a wireless power transmission system. Its design and optimization have a direct impact on the transmission efficiency, power, and transmission distance of the system. In order to improve the problem of poor anti-offset performance of two-dimensional coupling coils, researchers have turned their attention to designing three-dimensional coupling coils with higher degrees of freedom. WPT technology based on three-dimensional coupling structure overcomes the limitation that two-dimensional structures can only transmit energy within a limited range. It has a higher degree of freedom and can achieve multi-angle and multi-directional energy transmission, providing a larger magnetic field coverage range, thereby greatly improving the efficiency and reliability of wireless energy transmission. In addition, three-dimensional coupling coils can charge multiple electronic devices at the same time, greatly improving the utilization of time and space. WPT technology is a new type of power transmission technology that can solve the constraints of wired cables, and the three-dimensional coupling structure can solve the limitations brought by the two-dimensional coupling structure, and obtain a higher degree of freedom in the wireless charging process, making it have great research significance and application value, and it is worthy of in-depth research.

[0006] Existing technology: Domestic and foreign scholars have conducted a lot of research on three-dimensional coupling structures. In the prior art, the Institute of Electronic Technology proposed a bowl-shaped transmitting coil, which consists of a flat spiral coil on the bottom surface and a conical spiral coil on the side. The wireless charging bowl has a three-dimensional structure and can generate a wider range of spatial magnetic fields, and effectively charge the electronic devices placed in the bowl in all directions. In the prior art, a three-dimensional wireless energy transmission system that uses multiple orthogonal resonators to achieve spatial freedom has been studied. The proposed transmitter includes three orthogonal resonators with a three-dimensional structure. The three orthogonal resonators are respectively located at the top and bottom of the substrate, forming an open box-shaped structure, which can also perform efficient power transmission in the case of lateral and angular misalignment. In the prior art, a new three-dimensional coil based on a 26-sided polyhedron is proposed as the winding structure of the transmitting coil, and the winding is performed in a non-overlapping regular monolithic winding method. Through this coil, it can be ensured that the winding direction of each planar coil is different from that of the adjacent planar coil, so that the magnetic fields between adjacent coils are mutually enhanced, and the spatial magnetic field density of the system is also enhanced, so that power can be stably and efficiently transmitted at any position. Na-Rae Kwon et al. designed an isolated three-dimensional multi-transmitting coil, using a simple single coil overlapping structure. By analyzing the mutual inductance between coils, the optimal overlapping interval was derived, so that the multiple coil systems have the minimum mutual inductance value, and each transmitting coil will not interfere with the adjacent coils. The coil system can significantly reduce interference to improve the power transmission efficiency through the isolation function. Nam Ha-Van et al. studied a new omnidirectional three-dimensional wireless energy transmission system with a cube transmitter, and evaluated the magnetic field strength of transmitting coils of different shapes to optimize the coil structure. In the absence of a current control method, low-cost manufacturing and relatively high efficiency were achieved. In wireless power transmission systems, simple two-dimensional coupling coils are usually used to study the various performances of WPT systems. The most common method is to optimize the physical parameters of the two-dimensional coil, such as the number of turns, turn spacing, and line width, to achieve the purpose of optimizing coil performance. However, in practical applications, it is inevitable that the receiving coil cannot be perfectly aligned with the transmitting coil due to lateral offset, longitudinal offset, or even angular rotation, which will lead to a significant decrease in the transmission efficiency between the transmitting and receiving coils. That is, due to the limitation of the layout of the two-dimensional coil itself, the coil itself has limited freedom and cannot have good anti-offset performance.

[0007] Based on the above-mentioned shortcomings, therefore, a lantern-type transmitting coil for wireless power transmission is needed to improve the above-mentioned shortcomings. Summary of the invention

[0008] The main object of the present invention is to provide a lantern-type transmitting coil for wireless power transmission.

[0009] The purpose of the present invention can be achieved by adopting the following technical solutions: A lantern-shaped transmitting coil for wireless power transmission includes a structure in which a limiting member is surrounded by four sides, a transmitting coil is surrounded and installed inside the limiting member, and a receiving coil is placed inside the limiting member; The limiter is composed of a top, a bottom and four sides, and the winding method of the top, the bottom and the four sides presents a cross-shaped straight line routing method, forming a three-dimensional transmitting coil composed of two mutually orthogonal hollow cuboids connected in series; The entire transmitting coil adopts a printed circuit board structure; The substrate thickness of the top and bottom of the stopper is set to 4mm, the side substrate thickness is the conventional 1.6mm, the coil copper layer thickness on the substrate is 1 ounce, and the size of the transmitting coil is , the number of turns is 11; The analysis of the coil magnetic field is mainly divided into two parts: One is the analysis of the magnetic fields of the top and bottom coils; Another is the magnetic field analysis of the side coils.

[0010] Preferably, six PCB boards are connected in series by welding and vias according to the designed shape of the transmitting coil to form a complete three-dimensional coupler, and wiring is performed on the front and back sides of the top and bottom PCB boards respectively. The operating frequency of the transmitting coil and the receiving coil is 13.56 MHz.

[0011] Preferably, by connecting the compensating capacitor and inductor to the transmitting coil and the receiving coil for tuning, after adjusting the value of the compensating capacitor and inductor, the resonant frequency of the transmitting coil and the receiving coil are adjusted to = 13.56MHz, so that the transmitting and receiving coils resonate to transfer energy. When the transmitting coil and the receiving coil are aligned, a transmission efficiency of 67.76% is obtained when the distance between the two is 20mm.

[0012] Preferably, the transmission distance between the transmitting coil and the receiving coil is 10-40 mm.

[0013] Preferably, the distance between the transmitting coils is increased to 20 mm - 40 mm; When the transmission distance is 15-25mm, the system's transmission efficiency is maintained at at least 60%, and when the transmission distance is 10-30mm, the efficiency can be maintained at at least 50%.

[0014] When the transmission distance between the simulated transmitting coil and the receiving coil is fixed at 20 mm, the impact of the WPT system's offset in the horizontal direction range of -40 mm to 40 mm on the system's transmission efficiency is analyzed.

[0015] Preferably, when the horizontal offset range is from -40 to 20 mm, the transmission efficiency is at least 50% in all cases, and when the offset distance is from -30 mm to 20 mm, the transmission efficiency is maintained at at least 60%.

[0016] Preferably, the transmission distance between the transmitting coil and the receiving coil is fixed at 10 mm, and the receiving coil is rotated at different angles within a range of -45° to 45°. The transmission efficiency of the system is analyzed, and when the rotation angle is between -15° and 15°, the efficiency of the coil is maintained at at least 65%.

[0017] Beneficial technical effects of the present invention: The lantern-shaped transmitting coil for wireless power transmission provided by the present invention, Advantage 1 - This paper designs a lantern-shaped three-dimensional resonant transmitting coil structure and a traditional planar circular spiral receiving structure. The operating frequency of the system based on the designed three-dimensional transmitting structure is 13.56MHz. The system's anti-deviance ability is greatly improved compared with the traditional coil. First, good power transmission can be performed within a transmission distance of 10-40 mm, and the efficiency is the highest at a transmission distance of 20mm, which is 67.78%.

[0018] Secondly, when the horizontal displacement range is from -30 mm to 20 mm, the fluctuation of transmission efficiency is relatively small, maintained above 60%, and has stability; Finally, when the receiving coil is angularly offset and the rotation angle is between -15° and 15°, the efficiency of the coil fluctuates very little and remains above 65%; Advantage 2: The designed three-dimensional transmitting coil can generate a magnetic field with a wider coverage in space, greatly improving the space utilization rate; Moreover, the coupling structure can solve the problem of a significant drop in efficiency when there is a lateral, longitudinal and angular offset, that is, it produces an anti-offset effect that is independent of the position of the receiving coil, and at the same time has lower self-loss and higher transmission efficiency, and can comprehensively improve the shortcomings of the two-dimensional coil. The three-dimensional coupling coil of this design is a new type of magnetic coupling resonance structure coil that can be relatively simply tuned; Advantage 3 - According to actual needs, the operating frequency of the system can be flexibly controlled by adjusting the value of the added compensation capacitor and inductor or modifying the line width, line spacing and number of turns of the coil. It is not necessary to remake the entire transmitting coil or receiving coil. Therefore, it has the advantages of high flexibility, wide application range, easy use and cost saving; Advantage 4 - The number of coils on the side, top and bottom of the transmitting coil can be appropriately increased or decreased according to actual application requirements. For example, in order to facilitate the placement of electronic equipment inside the transmitting coil, one side PCB board can be reduced, the top or bottom can be removed to form a basket-shaped coil, or one or two sides can be removed to form a mailbox shape, or only two sides can be retained to form an L-shaped transmitting coil, and three sides can be retained to form a transmitting coil structure with only one vertex; Advantage 5: The system coil structure is suitable for wireless charging of small and medium-sized electrical devices in real life, easy to place, simple and convenient; Advantage 6 - The shape of the transmitting coil can also be flexibly controlled. If you want the magnetic field generated by the transmitting coil to be more uniform, the top and bottom of the transmitting coil can be designed to be hexagonal or even octagonal, or other polygonal or circular, elliptical, conical, truncated cone, square cone, etc., and the number of corresponding transmitting coil sides can be increased as the number of top sides changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A structural diagram of a transmitting coil of a preferred embodiment of a lantern-type transmitting coil for wireless power transmission according to the present invention; Figure 2 Schematic diagrams of the PCB structures (a), (b), (c) and (d) of the top and bottom of a transmitting coil according to a preferred embodiment of a lantern-type transmitting coil for wireless power transmission of the present invention; Figure 3 A diagram showing the magnetic field strength at the bottom and side of a transmitting coil of a preferred embodiment of a lantern-type transmitting coil for wireless power transmission according to the present invention; Figure 4 A structural diagram of a receiving coil according to a preferred embodiment of a lantern-type transmitting coil for wireless power transmission of the present invention; Figure 5 A 3D diagram of a WPT system simulation model of a preferred embodiment of a lantern-type transmitting coil for wireless power transmission according to the present invention; Figure 6 A simulation diagram of the resonance frequencies of a transmitting coil and a receiving coil according to a preferred embodiment of a lantern-type transmitting coil for wireless power transmission of the present invention; Figure 7 A simulation diagram of the resonance frequencies of a transmitting coil and a receiving coil according to a preferred embodiment of a lantern-type transmitting coil for wireless power transmission of the present invention; Figure 8 A transmission efficiency diagram of a lantern-type transmitting coil for wireless power transmission according to a preferred embodiment of the present invention at a transmission distance of 20 mm; Fig. 9A graph showing the transmission efficiency of a lantern-type transmitting coil for wireless power transmission according to a preferred embodiment of the present invention as a function of the transmission distance of the coil; Fig.10 A graph showing the variation of WPT transmission efficiency with coil horizontal offset distance according to a preferred embodiment of a lantern-type transmitting coil for wireless power transmission of the present invention; Fig.11 FIG. 1 is a graph showing the variation of WPT transmission efficiency with coil angle offset according to a preferred embodiment of a lantern-type transmitting coil for wireless power transmission according to the present invention.

[0020] In the figure: 1. Limiting member; 2. Transmitting coil; 3. Receiving coil. DETAILED DESCRIPTION

[0021] In order to make the technical solution of the present invention more clear and specific to those skilled in the art, the present invention is further described in detail below in conjunction with embodiments and drawings, but the implementation manner of the present invention is not limited thereto.

[0022] like Figure 1 - Fig.11 As shown, the lantern-shaped transmitting coil for wireless power transmission provided in this embodiment includes a limiting member 1 surrounded by a mounting structure on four sides, a transmitting coil 2 is mounted around the inner side of the limiting member 1, and a receiving coil 3 is placed in the limiting member 1; The stopper 1 is composed of a top, a bottom and four sides, and the winding method of the top, the bottom and the four sides presents a cross-shaped straight line routing method, forming a three-dimensional transmitting coil composed of two mutually orthogonal hollow cuboids connected in series; The entire transmitting coil 2 adopts a printed circuit board structure; The substrate thickness of the top and bottom of the stopper 1 is set to 4mm, the side substrate thickness is the conventional 1.6mm, the thickness of the coil copper layer on the substrate is 1 ounce, and the size of the transmitting coil 2 is , the number of turns is 11; The analysis of the coil magnetic field is mainly divided into two parts: One is the analysis of the magnetic fields of the top and bottom coils; Another is the magnetic field analysis of the side coils.

[0023] Six PCB boards are connected in series according to the designed transmitting coil shape through welding and vias to form a complete three-dimensional coupler. The wiring is carried out on the front and back sides of the top and bottom PCB boards respectively. The operating frequency of the transmitting coil 2 and the receiving coil 3 is 13.56MHz.

[0024] By connecting the compensation capacitor and inductor to the transmitting coil and the receiving coil for tuning, after adjusting the value of the compensation capacitor and inductor, the resonant frequency of the transmitting coil 2 and the receiving coil 3 are adjusted to = 13.56MHz, so that the transmitting and receiving coils resonate to transfer energy. When the transmitting coil 2 and the receiving coil 3 are aligned, a transmission efficiency of 67.76% is obtained when the distance between the two is 20mm.

[0025] The transmission distance between the transmitting coil 2 and the receiving coil 3 is 10-40 mm.

[0026] The distance of transmitting coil 2 is increased to 20mm-40mm; When the transmission distance is 15-25mm, the system's transmission efficiency is maintained at at least 60%, and when the transmission distance is 10-30mm, the efficiency can be maintained at at least 50%.

[0027] When the transmission distance between the simulated transmitting coil and the receiving coil is fixed at 20 mm, the impact of the WPT system's offset in the horizontal direction range of -40 mm to 40 mm on the system's transmission efficiency is analyzed.

[0028] The transmission efficiency is at least 50% in all cases when the horizontal offset range is -40 to 20 mm, and the transmission efficiency remains at least 60% in the offset distance range of -30 mm to 20 mm.

[0029] The transmission distance between the transmitting coil 2 and the receiving coil 3 is fixed at 10 mm. The receiving coil is rotated at different angles within a range of -45° to 45°. The transmission efficiency of the system is analyzed. When the rotation angle is between -15° and 15°, the efficiency of the coil is maintained at at least 65%.

[0030] like Figure 1 - Fig.11 As shown, the working process of the lantern-shaped transmitting coil for wireless power transmission provided in this embodiment is as follows: Step 1: The present invention should set its operating frequency to 13.56 MHz according to the requirements of practical applications. The WPT system based on the three-dimensional coupling coil structure includes a lantern-shaped three-dimensional transmitting coil and a traditional planar circular spiral receiving coil, wherein the two pairs of compensation capacitors and inductors added to the transmitting coil are C1, C2, L1 and L2, forming two LC impedance matching to adjust the operating frequency of the transmitting coil; The receiving coil end is only connected to a pair of compensation capacitors and inductors C R , L R , the receiving coil is tuned by LC impedance matching, C S is the total capacitance of the transmitting coil, L S is the total inductance of the transmitting coil; the resonant frequency of the transmitting coil and the receiving coil is expressed as: , where L 总 is the total equivalent inductance of L1 and L2, C 总 is the total capacitance of C1 and C2; Step 2: As above Figure 1 As shown in the figure, we propose a new lantern-shaped three-dimensional transmitting coil. The entire transmitting coil consists of a top, a bottom and four sides. The winding method of the top and the bottom is the same, both presenting a cross-shaped winding, as shown below Figure 2 (a) and 2(b); The four sides also use the same winding method, all of which use straight line routing, as shown below Figure 2 As shown in (c) and 2 (d), a three-dimensional transmitting coil is finally formed by two mutually orthogonal hollow cuboids connected in series. The entire transmitting coil adopts a printed circuit board structure. The PCB substrate material is FR-4 or other materials. According to the characteristics of the simulation grid division calculation, in order to facilitate the simulation, the top and bottom substrate thickness is set to 4mm, the side substrate thickness is the conventional 1.6mm, the coil copper layer thickness on the substrate is 1 ounce, and the size of the transmitting coil is , the number of turns is 11; The analysis of the coil magnetic field is mainly divided into two parts. One is the analysis of the magnetic field of the top and bottom coils. Since the winding methods of the top and bottom are the same and combined with the convenience of practical application, the bottom is selected as an example for analysis, as follows Figure 3 As shown in (a), the designed transmitting coil can generate a magnetic field with good uniformity. The other is the magnetic field analysis of the side coil. The winding method of the four sides is also the same, so one side is taken as an example for analysis; as follows Figure 3 As shown in (b), a magnetic field with good uniformity can also be generated around the side coil. Therefore, compared with the traditional two-dimensional transmitting coil, the three-dimensional transmitting coil of this design can generate a magnetic field on each surface, making the receiving coil more freely placed, thereby realizing multi-angle and multi-directional energy transmission; Step 3: If Figure 4 As shown in the figure, since the main research is on the structure and performance of the three-dimensional transmitting coil, the designed receiving coil should have a simple structure, suitable size, easy to study, and suitable for embedding in electrical equipment. Therefore, the traditional circular planar spiral coil is selected, and the size of the designed receiving coil is , the PCB substrate material is FR-4, the substrate thickness is 1.6mm, the coil copper layer thickness is 1 ounce, the coil turns are 12, and the receiving coil of suitable size can meet the requirements of being placed inside the transmitting coil and can also receive the transmitted energy to the maximum extent; The following Table I shows the specific physical dimensions of the transmitting coil and the receiving coil; Table I Model physical dimensions parameters ; Six PCB boards are connected in series by welding and vias according to the designed transmitting coil shape to form a complete three-dimensional coupler; In order to avoid the problem of overlapping top and bottom cross-shaped traces, the traces are routed on the front and back sides of the top and bottom PCB boards respectively. Figure 2 As shown in (a) and 2 (b), the feeding mode of the coil selects side feeding to introduce excitation; The determined coil operating frequency is 13.56MHz. In order to make both the transmitting coil and the receiving coil at the set operating frequency and to increase the quality factor (Q value) of the coil, it is chosen to tune by adding compensation capacitors and inductors; Two capacitors and inductors are added to the transmitting coil for impedance matching (as shown above). Figure 2 a) The orange part) can well increase the Q value and tuning. The receiving coil end only adds a capacitor and an inductor to achieve the simplest tuning purpose. The feed line method used is also side feed, such as Figure 4 As shown in (b), the coil is connected to the back of the PCB through a metallized via, one end is connected to the excitation source and the other end is grounded. Table 2 shows the values ​​of the compensation capacitance and inductance of each coil.

[0031] Table 2 Parameters of model compensation capacitor and inductor ; The 3D diagram of the simulation model is as follows Figure 5 As shown; The designed WPT system based on three-dimensional coupling coil is simulated and analyzed using HFSS electromagnetic simulation software. By connecting the compensating capacitor and inductor to the transmitting coil and the receiving coil (as shown above), Figure 2 a) Orange part and Figure 4 b) The dark green part) is tuned as follows Figure 6 As shown, after adjusting the values ​​of the compensation capacitor and inductor, the resonant frequencies of the transmitting coil and the receiving coil are adjusted to = 13.56MHz, making the transmitting and receiving coils resonate and transfer energy; When the transmitting coil and the receiving coil are perfectly aligned, the best transmission efficiency of 67.76% is obtained when the distance between the two is 20mm. The transmission efficiency of the system is as follows Figure 7 As shown; Step 4: The transmission performance of the designed coil is analyzed from three aspects; Firstly, the change of transmission performance when the transmission distance between the transmitting coil and the receiving coil changes (i.e., when the vertical offset occurs) under this design structure is explored. The influence of the change of transmission distance on the transmission performance of the transmitting and receiving coils is simulated by HFSS simulation software, and the transmission efficiency when the transmission distance between the transmitting coil and the receiving coil is 10-40mm is obtained as follows Figure 8 As shown; As can be seen from the above figure, when the coil transmission distance increases from 20mm to 40mm, the transmission efficiency of the WPT system based on the three-dimensional coupling coil decreases with the increase of the transmission distance. When the transmission distance is 15-25mm, the transmission efficiency of the system remains above 60%, and when the transmission distance is 10-30mm, the efficiency can also be maintained above 50%. It can be seen that the present invention can maintain stable and efficient transmission efficiency when the transmission distance changes, and improves the anti-deviation ability in the vertical direction; Secondly, the influence of horizontal offset on transmission efficiency is as follows: Fig. 9 As shown in the figure, when the transmission distance between the simulated transmitting coil and the receiving coil is fixed at 20 mm, the impact of the WPT system offset in the horizontal direction range of -40 mm to 40 mm on the system transmission efficiency; Again, when the horizontal offset range is -40 to 20 mm, the transmission efficiency is all above 50%, and when the offset distance is -30 mm to 20 mm, the fluctuation of the transmission efficiency is relatively small, maintained above 60%, and has stability; Finally, the effect of angle offset on the transmission efficiency is investigated. Fig.10 As shown, the transmission distance between the transmitting coil and the receiving coil is fixed at 10 mm, and the receiving coil is rotated at different angles (the rotation range is -45° to 45°) to analyze the transmission efficiency of the system; from Fig.10 It can be seen that when the rotation angle is between -15° and 15°, the efficiency of the coil fluctuates very little and remains above 65%.

[0032] Embodiment 1: Compared with the traditional two-dimensional transmitting coil, the three-dimensional transmitting coil designed by the present invention has greatly improved anti-deviation capability in vertical direction, horizontal direction or angular rotation. Firstly, it can perform efficient power transmission within a transmission distance of 10mm-40mm, and the efficiency is the highest at a transmission distance of 20mm, which is 67.78%; More importantly, when the transmission distance is 15mm-25mm, the energy transmission efficiency of the system can even be maintained above 60%; Secondly, when the horizontal offset range is from -30mm to 20mm, the energy transmission efficiency can be kept stable, which is kept above 60%, which reflects the stability of the transmission efficiency of the coil. Finally, when the transmission distance between the fixed transmitting coil and the receiving coil is 10mm, the angle offset occurs and the rotation angle is in the range of -15° to 15°, the transmission efficiency of the coil fluctuates very little, which is kept above 65%; The coil structure of the present invention is a three-dimensional coil structure formed by making full use of the space where the coil is located on the basis of the two-dimensional coil structure, which can make up for the shortcomings of the two-dimensional coil while retaining the advantages of the two-dimensional coil. The three-dimensional coil structure of the present invention is compact, beautiful in appearance, easy to place, convenient to use, and has a wide range of applications. The operating frequency meets the requirements of the operating frequency range specified by international standards. According to actual needs, the value and quantity of the compensation capacitor and inductor used for impedance matching can be adjusted, the coil operating frequency can be flexibly adjusted or the coil performance can be optimized. The shapes of the transmitting coil and the receiving coil can also be modified according to actual needs or aesthetic requirements. The materials used in the coils are the most commonly used materials, which can achieve higher power transmission efficiency at a lower cost.

[0033] The above description is only a further embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and concepts of the present invention within the scope disclosed by the present invention, which belong to the protection scope of the present invention.

Claims

1. A lantern-shaped transmitting coil for wireless power transmission, characterized in that: It comprises a structure in which a limiting member (1) is surrounded by four sides, a transmitting coil (2) is surrounded and installed inside the limiting member (1), and a receiving coil (3) is placed inside the limiting member (1); The limiting member (1) is composed of a top, a bottom and four side surfaces, and the winding method of the top, the bottom and the four side surfaces presents a cross-shaped straight line routing method, forming a three-dimensional transmitting coil composed of two mutually orthogonal hollow rectangular blocks connected in series; The entire transmitting coil (2) adopts a printed circuit board structure; The thickness of the substrate at the top and bottom of the stopper (1) is set to 4mm, the thickness of the side substrate is the conventional 1.6mm, the thickness of the coil copper layer on the substrate is 1 ounce, and the size of the transmitting coil (2) is 200×200×200mm 3 , the number of turns is 11; The analysis of the coil magnetic field is mainly divided into two parts: One is the analysis of the magnetic fields of the top and bottom coils; Another is the magnetic field analysis of the side coils.

2. The lantern-shaped transmitting coil for wireless power transmission according to claim 1, characterized in that: Six PCB boards are connected in series according to the shape of the designed transmitting coil by welding and vias to form a complete three-dimensional coupler. The wiring is respectively carried out on the front and back sides of the top and bottom PCB boards. The operating frequency of the transmitting coil (2) and the receiving coil (3) is 13.56 MHz.

3. The lantern-shaped transmitting coil for wireless power transmission according to claim 1, characterized in that: By connecting the compensating capacitor and inductor to the transmitting coil and the receiving coil for tuning, after adjusting the values ​​of the compensating capacitor and inductor, the resonant frequencies of the transmitting coil (2) and the receiving coil (3) are adjusted to f=13.56MHz, so that the transmitting and receiving coils resonate to transfer energy. When the transmitting coil (2) and the receiving coil (3) are aligned, a transmission efficiency of 67.76% is obtained at a distance of 20mm between the two.

4. The lantern-shaped transmitting coil for wireless power transmission according to claim 1, characterized in that: The transmission distance between the transmitting coil (2) and the receiving coil (3) is 10-40 mm.

5. The lantern-shaped transmitting coil for wireless power transmission according to claim 1, characterized in that: The distance of the transmitting coil (2) is increased to 20 mm - 40 mm; When the transmission distance is 15-25mm, the transmission efficiency of the system is maintained at at least 60%, and when the transmission distance is 10-30mm, the efficiency can be maintained at at least 50%. When the transmission distance between the simulated transmitting coil and the receiving coil is fixed at 20 mm, the impact of the WPT system's offset in the horizontal direction range of -40 mm to 40 mm on the system's transmission efficiency is analyzed.

6. The lantern-shaped transmitting coil for wireless power transmission according to claim 1, characterized in that: When the horizontal displacement range is from -40mm to 20mm, the transmission efficiency is at least 50% in all cases, and when the displacement distance is from -30mm to 20mm, the transmission efficiency is maintained at at least 60%.

7. The lantern-shaped transmitting coil for wireless power transmission according to claim 1, characterized in that: The transmission distance between the transmitting coil (2) and the receiving coil (3) is fixed at 10 mm, and the receiving coil is rotated at different angles within a range of -45° to 45°. The transmission efficiency of the system is analyzed, and when the rotation angle is between -15° and 15°, the efficiency of the coil is maintained at at least 65%.

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