An I-shaped ferrite with a high coupling coefficient

Abstract

This invention proposes a high-coupling-coefficient "I"-shaped ferrite core, comprising a ferrite core, a receiving coil, and a metal shielding plate. The ferrite core employs an "I"-shaped structure formed from ferrite sheets; the receiving coil is a DD-type compensation coil; the shielding module is a fully covered aluminum plate in the form of ferrite; the receiving coil is laid flat on the ferrite core, and the metal shielding layer is placed outside the coil, with the centers of all three components aligned in a straight line. This invention saves space and weight on the receiving side of a wireless power transmission system while enhancing coupling and anti-offset performance.

Description

Technical Field

[0001] This invention relates to wireless power transmission, and more particularly to an I-shaped ferrite with a high coupling coefficient. Background Technology

[0002] In the field of wireless charging for electric vehicles, magnetic coupling resonance technology has become the primary charging method due to its advantages such as high energy transmission power and efficiency, long transmission distance, and less stringent requirements on transmission direction. In addition to the transceiver coils, wireless power transmission systems typically incorporate ferrite cores in their coupling mechanisms to enhance the coupling. However, the addition of ferrite cores often causes nonlinear distortion of the magnetic field between the transceiver coils, altering the electromagnetic environment surrounding the wireless charging system's coupling mechanism. Furthermore, the magnetic field changes caused by ferrite cores between the transceiver coils are nonlinear, making it impossible to derive the design of ferrite cores using formula-based theories. Therefore, research on the optimization of the core structure is of great significance. Summary of the Invention

[0003] The purpose of this invention is to propose an I-shaped ferrite with a high coupling coefficient to improve the coupling coefficient of vehicle wireless power transmission systems.

[0004] The technical solution to achieve the purpose of this invention is: a high-coupling-coefficient I-shaped ferrite core, comprising a ferrite core, a receiving coil, and a metal shielding plate, wherein:

[0005] The ferrite core adopts an "I"-shaped structure formed by ferrite sheets; the receiving coil is a DD-type compensation coil; the metal shielding plate is an aluminum plate in the form of full-coverage ferrite; the receiving coil is laid flat on the ferrite core, and the metal shielding plate is placed outside the coil, with the centers of the three located on the same straight line.

[0006] Furthermore, the position of the ferrite sheets is determined by a deep learning model. The distribution state of each ferrite sheet is used as the input parameter of the neural network, and the mutual inductance is used as the output parameter of the neural network. After training the deep learning model by obtaining multiple sets of data through Ansys environment simulation experiments, the model can be used to calculate the distribution state with the highest mutual inductance for different numbers of ferrite sheets.

[0007] Furthermore, the ferrite core consists of 40 100 × 150 × 2.5 mm ferrite sheets. A 6×8 position matrix is ​​set up, with 8 ferrite sheets placed in rows 1 and 6, and 6 ferrite sheets placed in rows 2, 3, 4, and 5. At the same time, the placement of all ferrite sheets satisfies central symmetry, that is, no ferrite sheets are placed in 8 regions [(2,1)(3,1)(4,1)(5,1)(2,8)(3,8)(4,8)(5,8)], and ferrite sheets are placed in the remaining positions.

[0008] Furthermore, the DD-type compensation coil is laid flat on the ferrite core at the receiving end, and the arrangement range does not exceed the "I"-shaped ferrite core. The outermost coil of a single D coil has a size of 300mm×600mm. The left and right D coils are wound in opposite directions, and the left and right D coils have the same turn spacing and number of turns, with a turn spacing of 2.1mm.

[0009] Furthermore, the metal shielding plate is positioned 10mm away from the transceiver coil on both sides, using a fully covered ferrite core with dimensions of 810mm × 910mm.

[0010] Compared with the prior art, the significant advantages of this invention are: only the four corner ferrite sheets are retained in columns 1 and 8, and no ferrite sheets are set in other positions, which reduces the amount of ferrite core material used, while improving the coupling coefficient and enhancing the anti-offset capability. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the I-shaped ferrite on the receiving coil side.

[0012] Figure 2 It is the algorithm's execution flow.

[0013] Figure 3 It is an 'I'-shaped ferrite core structure. Dark gray indicates no ferrite is placed, while light gray indicates ferrite sheets are placed.

[0014] Figure 4 This is a top view of an I-shaped ferrite system with a high coupling coefficient.

[0015] Figure 5 These are the simulation results of the x, y, and z axis offsets of the I-shaped and flat ferrite coupling mechanism. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0017] like Figure 1 As shown, a high coupling coefficient 'I'-shaped ferrite includes a ferrite core, a receiving coil, and a metal shielding plate. The ferrite core adopts an 'I'-shaped structure formed by ferrite sheets, the receiving coil is laid flat on the ferrite core, and the metal shielding plate is placed outside the coil.

[0018] 1) Ferrite core:

[0019] The wireless charging system for a standard home parking space (2500×5500mm) typically has a transmitter that can be fixed at 2000×2500mm. Considering that the transceiver has a certain resistance to offset and that the system is available in the chassis of a typical new energy vehicle, the outermost layer of the 'I'-shaped ferrite system with a high coupling coefficient in this invention has a size of 810×910mm. The conventional flat ferrite core is divided into individual ferrite sheets, and the selected ferrite sheet size is 100 × 150 × 2.5 mm.

[0020] Meanwhile, based on deep learning, the distribution state of each ferrite sheet is used as the input parameter of the neural network, and the mutual inductance is used as the output parameter of the neural network to determine the arrangement of the ferrite core.

[0021] like Figure 2 As shown, in the learning algorithm operation mechanism of ferrite core structure design, the input parameter is a 6×8 two-dimensional matrix. When a ferrite sheet is placed, the corresponding position is represented by "1", and when no ferrite sheet is placed, the corresponding position is represented by "0". Only the mutual inductance is the variable to be trained for the learning algorithm. After the ferrite sheet state is selected, the selected information is input into the Ansys Maxwell environment. After running the simulation, the environment returns the mutual inductance of the transmitting and receiving coils as the algorithm's reward. By using the accumulated reward data stored in the neural network, the position of the ferrite sheet that generates a high coupling coefficient between the transmitting and receiving coils is selected.

[0022] A total of 100 random locations were generated in the early stage, and some data with high mutual inductance and coupling coefficient are shown in Table 1.

[0023] The coupling coefficient k is defined as follows:

[0024]

[0025] M is the mutual inductance between the transmitting and receiving coils, and L1 and L2 are the self-inductances of the transmitting and receiving coils, respectively.

[0026] Table 1 Partial Training Data

[0027]

[0028] Get as Figure 3 The 'I'-shaped ferrite core structure shown provides the highest coupling coefficient between the transmitting and receiving coils. The 'I'-shaped ferrite core structure consists of 40 100 × 150 × 2.5 mm ferrite sheets. Eight ferrite sheets are placed in rows 1 and 6, and six ferrite sheets are placed in rows 2, 3, 4, and 5. This means that eight areas [(2,1)(3,1)(4,1)(5,1)(2,8)(3,8)(4,8)(5,8)] are left without ferrite sheets, while the placement of all ferrite sheets satisfies central symmetry.

[0029] 2) Receiving coil: The DD-type compensating coil is laid flat on the ferrite core at the receiving end, and its arrangement range does not exceed that of the 'I'-shaped ferrite core, such as... Figure 4 The diagram shows a top view of an I-shaped ferrite system with a high coupling coefficient. The outermost conductor of a single D-coil is rectangular, measuring 300mm × 600mm. The input wire is wound clockwise from the innermost side of the left D-coil, with a turn spacing of 2.1mm. Starting with the outermost conductor of the left D-coil, the right D-coil is wound in series, starting from the outermost side and proceeding counter-clockwise to the innermost side, which is the output wire. The turn spacing and number of turns are the same for both the left and right D-coils.

[0030] 3) Metal shielding plate: The metal shielding plate is positioned on both sides of the transceiver coil, 10mm away from the coil, and in contact with the ferrite core. Using a fully covered ferrite material, the metal shielding plate measures 810mm × 910mm, appropriate for the coil size proposed in this invention.

[0031] Example

[0032] To verify the effectiveness of the present invention, a comparative analysis was conducted between the ferrite of the present invention and the conventional flat ferrite structure.

[0033] The simulation parameters of the transceiver coil are shown in Table 2.

[0034] Table 2. Parameters of Transceiver Coils

[0035]

[0036] The coupling coefficient k is defined as follows:

[0037]

[0038] The comparison results of the mutual inductance and coupling coefficient k between the transmitting and receiving coils in terms of their lateral offsets on the x, y, and z axes are as follows: Figure 5 As shown in the figure. Compared with the conventional flat design, the proposed "I"-shaped ferrite system reduces self-inductance by 3.3%, increases mutual inductance by 1.2%, and improves coupling coefficient by 1.7%. Furthermore, the material usage of the "I"-shaped ferrite core is only 83.3% of that of the conventional flat design, reducing material usage by 16.7%.

[0039] In summary, this invention realizes a wireless power transmission structure based on an I-shaped ferrite system, which improves the efficiency of wireless charging for electric vehicles while reducing the space and weight of the receiving system, providing a new approach for the development of the wireless charging industry for electric vehicles.

[0040] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0041] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A high-coupling-coefficient I-shaped ferrite, characterized in that, Includes a ferrite core, a receiving coil, and a metal shielding plate, among which: The ferrite core adopts an "I"-shaped structure formed by ferrite sheets; the receiving coil is a DD-type compensation coil; the metal shielding plate is an aluminum plate in the form of full-coverage ferrite; the receiving coil is laid flat on the ferrite core, and the metal shielding plate is placed outside the coil, with the centers of the three located on the same straight line; in: The position of the ferrite sheet is determined by a deep learning model. The distribution state of each ferrite sheet is used as the input parameter of the neural network, and the mutual inductance is used as the output parameter of the neural network. After training the deep learning model by obtaining multiple sets of data through Ansys environment simulation experiments, the model can be used to calculate the distribution state with the highest mutual inductance for different numbers of ferrite sheets. The ferrite core consists of 40 100 × 150 × 2.5 mm ferrite sheets. A 6×8 position matrix is ​​set up, with 8 ferrite sheets placed in rows 1 and 6, and 6 ferrite sheets placed in rows 2, 3, 4, and 5. At the same time, the placement of all ferrite sheets satisfies central symmetry, that is, no ferrite sheets are placed in 8 regions [(2,1)(3,1)(4,1)(5,1)(2,8)(3,8)(4,8)(5,8)], and ferrite sheets are placed in the remaining positions. The DD-type compensation coil is laid flat on the ferrite core at the receiving end, and the arrangement range does not exceed the "I"-shaped ferrite core. The outermost coil of a single D coil has a size of 300mm×600mm. The left and right D coils are wound in opposite directions, and the left and right D coils have the same turn spacing and number of turns, with a turn spacing of 2.1mm. The metal shielding plate is positioned 10mm away from the transceiver coil on both sides, using a full-coverage ferrite core with dimensions of 810mm × 910mm.

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