Anti-offset wireless power transmission magnetic coupling mechanism and parameter design method thereof

Abstract

The invention discloses an anti-offset wireless power transmission magnetic coupling mechanism and a parameter design method thereof, and relates to the technical field of wireless power transmission, and the anti-offset wireless power transmission magnetic coupling mechanism comprises a transmitting coil group and a square receiving coil which are coupled; the transmitting coil group comprises an outer square transmitting coil, four groups of middle square transmitting coils and an inner square transmitting coil which are connected in series; the middle square transmitting coil comprises an outer transmitting coil and an inner transmitting coil, and the square receiving coil comprises an outer receiving coil and an inner receiving coil; the outer square transmitting coil, the outer transmitting coil and the outer receiving coil are compact coils, and the inner square transmitting coil, the inner transmitting coil and the inner receiving coil are loose coils. The magnetic coupling mechanism based on the scheme is easy to manufacture and can achieve a good anti-offset effect.

Description

Technical Field

[0001] This invention relates to the field of wireless power transmission technology, and in particular to an anti-offset wireless power transmission magnetic coupling mechanism and its parameter design method. Background Technology

[0002] Wireless power transfer (WPT) technology has attracted much attention due to its convenience and security. It achieves power transfer through a magnetic coupling mechanism consisting of transmitting and receiving coils. Because there is a certain transmission distance between the transmitting and receiving sides of the magnetic coupling mechanism without a physical connection, the coils on both sides are prone to misalignment. When this misalignment occurs, the transmission efficiency and output power of the wireless power transfer system drop sharply, thus requiring improved anti-misalignment capabilities. Existing anti-misalignment schemes for wireless power transfer systems typically rely on active impedance matching circuits (such as adding a DC-DC converter at the output) or closed-loop control strategies using bilateral communication, resulting in high system complexity. Summary of the Invention

[0003] This invention provides a magnetic coupling mechanism for offset-resistant wireless power transfer and its parameter design method, which solves the technical problem of high complexity in existing offset-resistant wireless power transfer systems.

[0004] The first aspect of the present invention provides an anti-offset wireless power transmission magnetic coupling mechanism, comprising a coupled transmitting coil group and a square receiving coil;

[0005] The transmitting coil group includes an outer square transmitting coil connected in series, four groups of middle square transmitting coils, and an inner square transmitting coil.

[0006] The four sets of central square transmitting coils are distributed around the square side circumference of the inner square transmitting coil;

[0007] The four sets of middle square transmitting coils and the inner square transmitting coils are located inside the outer square transmitting coil. The coil center of the outer square transmitting coil, the geometric center of the four sets of middle square transmitting coils, and the coil center of the inner square transmitting coil coincide.

[0008] The outer square transmitting coil and the square receiving coil are asymmetrical coils;

[0009] The magnetic field of the middle square transmitting coil is stronger than that of the inner square transmitting coil;

[0010] The square transmitting coil includes an outer transmitting coil and an inner transmitting coil, and the square receiving coil includes an outer receiving coil and an inner receiving coil;

[0011] The outer square transmitting coil, the outer transmitting coil, and the outer receiving coil are compact coils, while the inner square transmitting coil, the inner transmitting coil, and the inner receiving coil are loose coils.

[0012] Furthermore, the offset distance between the center of the middle square transmitting coil and the center of the inner square transmitting coil is 0.395 * the inner side length of the outer square transmitting coil + 0.105 * the outer side length of the inner square transmitting coil.

[0013] Furthermore, the outer side length of the inner square transmitting coil is greater than the outer side length of the middle square transmitting coil;

[0014] The inner square transmitting coil has fewer turns than the middle square transmitting coil.

[0015] Furthermore, the ratio of the turn spacing to the wire diameter of the compact coil is... The ratio of the turn spacing to the wire diameter of the loose coil is... .

[0016] The second aspect of this invention provides a parameter design method for an anti-offset wireless power transfer magnetic coupling mechanism, comprising:

[0017] Based on the mutual inductance expression based on vector magnetic potential, the parameters of the first target coil are determined when the external receiving mutual inductance between the outer square transmitting coil and the square receiving coil is greater than or equal to the preset minimum mutual inductance value and the external receiving mutual inductance is at its maximum. The parameters of the first target coil include the outer side length, number of turns and turn spacing of the outer square transmitting coil, as well as the outer side length, number of turns and turn spacing of the square receiving coil.

[0018] Based on the mutual inductance expression and the parameters of the first target coil, the square receiving coil is offset along the X-axis, Y-axis and Z-axis respectively, and the corresponding axis offset mutual inductance curves are constructed and the associated axis offset mutual inductance complementary curves are determined.

[0019] Based on the first target coil parameters and the mutual inductance expression, the mutual inductance between the square transmitting coil and the inner square transmitting coil and the square receiving coil in the four groups is determined, and the mutual inductance between the inner square transmitting coil and the square receiving coil is determined using the mutual inductance between the inner square receiving coil and the square receiving coil. The mutual inductance between the inner square receiving coil and the square receiving coil is used to determine the complementary curve of ...

[0020] Based on the first target coil parameters and the mutual inductance expression, the in-center receiving offset mutual inductance corresponding to each offset of the square receiving coil along the X-axis, Y-axis and Z-axis is determined. The incremental mutual inductance corresponding to each offset is extracted from the complementary incremental curve of the mutual inductance of each axis offset and the corresponding mutual inductance offset range is determined. The maximum offset of the in-center receiving offset mutual inductance within its respective mutual inductance offset range is determined and the combined offset is output.

[0021] Determine the parameters of the second target coil corresponding to the maximum combined offset. The parameters of the second target coil include the outer side length, number of turns and turn spacing of the middle square transmitting coil, and the outer side length, number of turns and turn spacing of the inner square transmitting coil.

[0022] The outer square transmitting coil and the inner square transmitting coil both satisfy the first coil parameter constraint, which includes [wire diameter * number of coil turns + (number of coil turns - 1) * turn spacing] - 1 > outer side length of coil / 2. The middle square transmitting coil and the square receiving coil both satisfy the second coil parameter constraint, which includes [wire diameter * number of turns of outer coil + (number of turns of outer coil - 1) * turn spacing of outer coil] + number of turns of inner coil * (turn spacing of inner coil + wire diameter) - 1 > outer side length of coil / 2.

[0023] Furthermore, the mutual inductance expression includes:

[0024] ;

[0025] ;

[0026] ;

[0027] ;

[0028] ;

[0029] ;

[0030] ;

[0031] In the formula, Indicates mutual intuition. Indicates the first One transmitting coil, Indicates the number of transmitting coils. Indicates the first One transmitting coil With receiving coil Mutual intuition between them This indicates the number of coil turns for each transmitting coil. This indicates the number of coil turns for each receiving coil. Indicates the first coil, Indicates the first coil, Indicates the first The first transmitting coil The first turn of the coil and the receiving coil Mutual inductance between coils Indicates the first of the transmitting coils The first turn of the coil and the receiving coil Mutual inductance of the coils Represents pi (π). Indicates the first of the transmitting coils The current in the coil, This represents the offset distance of the receiving coil's center relative to the transmitting coil's center along the X-axis. This represents the offset distance of the receiving coil's center relative to the transmitting coil's center along the Y-axis. Indicates the receiving coil number The outer half-width of the coil Indicates the receiving coil number The outer half length of the coil This indicates the radius of the wire used to wind the coil. Represents the natural constant. Represents the imaginary unit. Spatial frequency domain coordinates representing the X-axis coordinates. The spatial frequency domain coordinates representing the Y-axis coordinates. Indicates the transverse spatial wavenumber modulus. This represents the coaxial perpendicular distance between the centers of the transmitting coil and the receiving coil. This represents the coefficient of the incident magnetic field along the Z-axis in the spatial frequency domain. This represents the weighting coefficient of the exponentially increasing term of the reflected magnetic field along the Z-axis in the spatial frequency domain. This represents the weighting coefficient of the exponential decay term of the reflected magnetic field along the Z-axis in the spatial frequency domain. Represents the permeability of free space. Indicates the first of the transmitting coils The outer half length of the coil Indicates the first of the transmitting coils The outer half-width of the coil Represents relative permeability. This represents the reflection coefficient.

[0032] The third aspect of this invention provides a parameter design device for an anti-offset wireless power transfer magnetic coupling mechanism, comprising:

[0033] The first parameter optimization module is used to determine the first target coil parameters when the external receiving head-on mutual inductance between the outer square transmitting coil and the square receiving coil is greater than or equal to a preset minimum mutual inductance value and the external receiving head-on mutual inductance is at its maximum, based on the mutual inductance expression based on vector magnetic potential. The first target coil parameters include the outer side length, number of coil turns and turn spacing of the outer square transmitting coil, as well as the outer side length, number of coil turns and turn spacing of the square receiving coil.

[0034] The offset curve construction module is used to offset the square receiving coil along the X-axis, Y-axis and Z-axis respectively based on the mutual inductance expression and the parameters of the first target coil, construct the corresponding axis offset mutual inductance curves and determine the associated axis offset mutual inductance complementary curves.

[0035] The offset curve adjustment module is used to determine the mutual inductance between the square transmitting coil and the inner square transmitting coil and the square receiving coil in four groups based on the first target coil parameters and the mutual inductance expression, and to determine the axial offset mutual inductance complementary incremental curve of each axial offset mutual inductance complementary curve using the mutual inductance between the square transmitting coil and the inner square transmitting coil.

[0036] The offset determination module is used to determine the in-center receiving offset mutual inductance corresponding to each offset of the square receiving coil along the X-axis, Y-axis and Z-axis respectively, based on the first target coil parameters and the mutual inductance expression; extract the incremental mutual inductance corresponding to each offset from the complementary incremental curve of the mutual inductance of each axis offset and determine the corresponding mutual inductance offset range; determine the maximum offset of the in-center receiving offset mutual inductance within its respective mutual inductance offset range and add them together to output the combined offset.

[0037] The second parameter optimization module is used to determine the second target coil parameters corresponding to the maximum combined offset. The second target coil parameters include the outer side length, number of turns and turn spacing of the middle square transmitting coil, as well as the outer side length, number of turns and turn spacing of the inner square transmitting coil.

[0038] The outer square transmitting coil and the inner square transmitting coil both satisfy the first coil parameter constraint, which includes [wire diameter * number of coil turns + (number of coil turns - 1) * turn spacing] - 1 > outer side length of coil / 2. The middle square transmitting coil and the square receiving coil both satisfy the second coil parameter constraint, which includes [wire diameter * number of turns of outer coil + (number of turns of outer coil - 1) * turn spacing of outer coil] + number of turns of inner coil * (turn spacing of inner coil + wire diameter) - 1 > outer side length of coil / 2.

[0039] A fourth aspect of the present invention provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor causes the processor to perform the steps of the parameter design method for the anti-offset wireless power transfer magnetic coupling mechanism as described in any of the preceding claims.

[0040] The fifth aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed, implements the parameter design method for the anti-offset wireless power transfer magnetic coupling mechanism as described in any of the preceding claims.

[0041] The sixth aspect of the present invention provides a computer program product comprising a computer program / instruction, wherein when the computer program / instruction is executed by a processor, it implements the parameter design method for the anti-offset wireless power transfer magnetic coupling mechanism as described in any of the preceding claims.

[0042] As can be seen from the above technical solutions, the present invention has the following advantages:

[0043] The first aspect of the present invention provides an anti-offset wireless power transmission magnetic coupling mechanism, including a coupled transmitting coil group and a square receiving coil; the transmitting coil group includes an outer square transmitting coil, four sets of middle square transmitting coils, and an inner square transmitting coil connected in series; the four sets of middle square transmitting coils are distributed around the square side circumference of the inner square transmitting coil; the four sets of middle square transmitting coils and the inner square transmitting coil are located inside the outer square transmitting coil, and the coil center of the outer square transmitting coil, the geometric center of the four sets of middle square transmitting coils, and the coil center of the inner square transmitting coil coincide; the outer square transmitting coil and the square receiving coil are asymmetrical coils; the magnetic field of the middle square transmitting coil is stronger than the magnetic field of the inner square transmitting coil; the middle square transmitting coil includes an outer transmitting coil and an inner transmitting coil, and the square receiving coil includes an outer receiving coil and an inner receiving coil; the outer square transmitting coil, the outer transmitting coil, and the outer receiving coil are compact coils, and the inner square transmitting coil, the inner transmitting coil, and the inner receiving coil are loose coils. Based on the above scheme, the magnetic coupling mechanism uses square coils with various winding methods as the foundation, combining the asymmetrical coil relationship between the outer square transmitting coil and the square receiving coil, as well as the strong and weak magnetic field relationship between the middle square transmitting coil and the inner square transmitting coil. The structure and manufacturing are simple and can achieve good anti-offset effect. This method of optimizing the magnetic field distribution through pure passive means simplifies the system-level structure and reduces costs, so that without adding complex circuits, it can simultaneously take into account low mutual inductance fluctuation rate and high system transmission efficiency of wireless power transmission system under large positional offset.

[0044] The second aspect of the present invention provides a parameter design method for an anti-offset wireless power transfer magnetic coupling mechanism, comprising: determining, according to a mutual inductance expression based on vector magnetic potential, the parameters of a first target coil when the external receiving mutual inductance between the outer square transmitting coil and the square receiving coil is greater than or equal to a preset minimum mutual inductance value and the external receiving mutual inductance is at its maximum; the first target coil parameters include the outer side length, number of turns, and turn spacing of the outer square transmitting coil, and the outer side length, number of turns, and turn spacing of the square receiving coil; based on the mutual inductance expression and the first target coil parameters, offsetting the square receiving coil along the X-axis, Y-axis, and Z-axis respectively, constructing corresponding axial offset mutual inductance curves and determining associated axial offset mutual inductance complementary curves; and based on the first target coil parameters and the mutual inductance expression, determining the parameters of the square transmitting coil and the inner square receiving coil in four groups. The inner and outer receiving inductances of the square transmitting coil and the square receiving coil are used to determine the axial offset mutual inductance complementary incremental curves of each axis offset mutual inductance complementary curve. Based on the first target coil parameters and mutual inductance expression, the inner receiving offset mutual inductance corresponding to each offset of the square receiving coil along the X-axis, Y-axis and Z-axis is determined. The incremental mutual inductance corresponding to each offset is extracted from the axial offset mutual inductance complementary incremental curves and the corresponding mutual inductance offset range is determined. The maximum offset of the inner receiving offset mutual inductance within its respective mutual inductance offset range is determined and summed to output the combined offset. The second target coil parameters corresponding to the maximum combined offset are determined. The second target coil parameters include the outer side length, number of turns and turn spacing of the middle square transmitting coil, and the outer side length, number of turns and turn spacing of the inner square transmitting coil. Based on the above scheme, the global optimization search of the three-axis offset distance was considered during the optimization process. Combined with the step-by-step configuration of the main and auxiliary coils, the curse of dimensionality in simultaneous optimization of multiple parameters was avoided. At the same time, mutual inductance curves, mutual inductance complementary curves, and mutual inductance complementary incremental curves were introduced as analysis tools to map the abstract spatial magnetic field distribution into a visualized mutual inductance characteristic curve, realizing the quantitative characterization of magnetic field coupling capability. By observing the mutual inductance complementary incremental curves, the magnetic field distribution of the required coil can be quickly diagnosed, thereby providing guidance for subsequent adjustment of the size of the transmitting coil and selection of the number of turns. This avoids the drawbacks of blind trial and error in traditional design and helps to quickly and reliably optimize to a magnetic coupling structure with strong anti-offset characteristics. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1This is a schematic diagram of an anti-offset wireless power transfer magnetic coupling mechanism provided in Embodiment 1 of the present invention. Figure 1 ;

[0047] Figure 2 This is a schematic diagram of an anti-offset wireless power transfer magnetic coupling mechanism provided in Embodiment 1 of the present invention. Figure 2 ;

[0048] Figure 3 This is a simplified schematic diagram of an anti-offset wireless power transfer magnetic coupling mechanism provided in Embodiment 1 of the present invention;

[0049] Figure 4 The flowchart illustrates the steps of a parameter design method for an anti-offset wireless power transfer magnetic coupling mechanism provided in Embodiment 2 of the present invention.

[0050] Figure 5 This is a schematic diagram of the overall architecture of the wireless power transmission system provided in Embodiment 2 of the present invention;

[0051] Figure 6 This is a schematic diagram of the equivalent circuit of the LCC-S type compensation network provided in Embodiment 2 of the present invention;

[0052] Figure 7 This is a schematic diagram of coil mutual inductance provided in Embodiment 2 of the present invention;

[0053] Figure 8 This is a schematic diagram of the mutual inductance volatility simulation curve provided in Embodiment 2 of the present invention;

[0054] Figure 9 This is a structural block diagram of a parameter design device for an anti-offset wireless power transmission magnetic coupling mechanism provided in Embodiment 3 of the present invention. Detailed Implementation

[0055] This invention provides an anti-offset wireless power transfer magnetic coupling mechanism and its parameter design method, which solves the technical problem that the existing anti-offset wireless power transfer magnetic coupling mechanism has a relatively complex structure.

[0056] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0057] Please see Figures 1 to 3 The present invention provides an anti-offset wireless power transmission magnetic coupling mechanism, comprising a coupled transmitting coil group and a square receiving coil 7;

[0058] The transmitting coil group includes an outer square transmitting coil 1 connected in series, four groups of middle square transmitting coils, and an inner square transmitting coil 6;

[0059] The four groups of square transmitting coils are distributed around the square side circumference of the inner square transmitting coil 6;

[0060] The four sets of square transmitting coils and the inner square transmitting coil 6 are located inside the outer square transmitting coil 1. The coil center of the outer square transmitting coil 1, the geometric center of the four sets of square transmitting coils, and the coil center of the inner square transmitting coil 6 coincide.

[0061] The outer square transmitting coil 1 and the square receiving coil 7 are asymmetrical coils;

[0062] The magnetic field of the middle square transmitting coil is stronger than that of the inner square transmitting coil 6;

[0063] The square transmitting coil 7 includes an outer transmitting coil and an inner transmitting coil, and the square receiving coil 7 includes an outer receiving coil and an inner receiving coil.

[0064] The outer square transmitting coil 1, the outer transmitting coil and the outer receiving coil are compact coils, while the inner square transmitting coil 6, the inner transmitting coil and the inner receiving coil are loose coils.

[0065] It should be noted that this embodiment designs a magnetic coupling mechanism for the LCC-S type wireless power transfer system, which is simple to manufacture and can achieve good anti-displacement effect:

[0066] The magnetic coupling mechanism in this embodiment includes a transmitting coil and a receiving coil, both of which are square coils with the same length and width, thus obtaining a transmitting coil group composed of multiple square transmitting coils. ) and square receiving coil 7 ( The transmitting coil group includes an outer square transmitting coil 1 connected in series. ), four groups of square transmitting coils and inner square transmitting coils 6 ( The current in the transmitting coil is in the same direction;

[0067] The coils are wound using wires of the same diameter. Both the square transmitting coil and the square receiving coil 7 are wound with a tightly wound outer section and a loosely wound inner section. The square transmitting coil and the square receiving coil 7 are divided into inner and outer coils, respectively. Thus, the square transmitting coil includes an outer transmitting coil and an inner transmitting coil, and the square receiving coil 7 includes an outer receiving coil and an inner receiving coil. At the same time, the outer square transmitting coil 1 is wound with a tightly wound coil, and the inner square transmitting coil 6 is wound with a loosely wound coil. In general, the outer square transmitting coil 1, the outer transmitting coil, and the outer receiving coil are all tightly wound coils, while the inner square transmitting coil 6, the inner transmitting coil, and the inner receiving coil are all loosely wound coils.

[0068] The four groups of square transmitting coils and inner square transmitting coil 6 are all located in outer square transmitting coil 1. The internal area of ​​the four sets of square transmitting coils includes the first square transmitting coil 2 ( ), the second square transmitting coil 3 ( ), the third square transmitting coil 4 ( ) and the fourth square transmitting coil 5 ( The four square transmitting coils are symmetrically distributed on the square sides of the inner square transmitting coil 6. At this time, the intersection of the coil centers of the four square transmitting coils forms their corresponding geometric center. The coil center refers to the center of symmetry of the geometric outline of the coil. At the same time, the coil center of the outer square transmitting coil 1, the geometric center of the four square transmitting coils, and the coil center of the inner square transmitting coil 6 all coincide. The outer square transmitting coil 1 and the square receiving coil 7 are set to be in an asymmetrical state. The magnetic field presented by the middle square transmitting coil is relatively stronger than that of the inner square transmitting coil 6. The two form a state of strong and weak magnetic fields.

[0069] In one specific embodiment of this example, the offset distance between the center of the middle square transmitting coil and the center of the inner square transmitting coil 6 is 0.395 * the inner side length of the outer square transmitting coil 1 + 0.105 * the outer side length of the inner square transmitting coil 6.

[0070] It should be noted that the middle square transmitting coils are distributed around the inner square transmitting coil 6 on the square side of the inner square transmitting coil 6. This is equivalent to each middle square transmitting coil being shifted by the same offset distance from the center of the inner square transmitting coil 6 in the positive X-axis direction, negative X-axis direction, positive Y-axis direction, and negative Y-axis direction, respectively. In a preferred implementation, this embodiment achieves better anti-offset effect by designing this offset distance to be the sum of 0.395 * the inner side length of the outer square transmitting coil 1 and 0.105 * the outer side length of the inner square transmitting coil 6. Here, the inner side length of the outer square transmitting coil 1 = the outer side length of the outer square transmitting coil 1 - 2 * the number of turns of the outer square transmitting coil 1 * the wire diameter - 2 * (the number of turns of the outer square transmitting coil 1 - 1) * the turn spacing of the outer square transmitting coil 1. It can be understood that the outer side length of the coil refers to the side length of the boundary formed by the outermost wire of the coil, the inner side length of the coil refers to the side length of the boundary formed by the innermost wire of the coil, and the wire diameter refers to the diameter of the wire used to wind the coil.

[0071] In one specific embodiment of this example, the outer side length of the inner square transmitting coil 6 is greater than the outer side length of the middle square transmitting coil;

[0072] The number of turns of the inner square transmitting coil 6 is less than the number of turns of the middle square transmitting coil.

[0073] It should be noted that in one design of this embodiment, the strength of the magnetic field between the inner square transmitting coil 6 and the middle square transmitting coil can be constructed by limiting the parameters of the number of coil turns and the outer side length of the coil. The number of coil turns of the inner square transmitting coil 6 is less than the number of coil turns of the middle square transmitting coil. At the same time, since the larger the size and the more dispersed the magnetic field lines, the weaker the central magnetic field is, and vice versa, the smaller the size and the more concentrated the magnetic field lines, the stronger the magnetic field is. That is, the larger the size of the coil, the greater its magnetic flux, and the greater the mutual inductance between it and the receiving coil. However, its magnetic field distribution will show that the central magnetic field is weaker. Therefore, the outer side length of the inner square transmitting coil 6 is designed to be greater than the outer side length of the middle square transmitting coil.

[0074] In one specific embodiment of this example, the ratio of the turn spacing to the wire diameter of the compact coil is: The ratio of the turn spacing to the wire diameter of a loose coil is .

[0075] It should be noted that, in order to optimize the magnetic field distribution, this embodiment considers further designing the turn spacing. Taking Litz wire as an example, the turn spacing of the tightly wound portion of the coil is defined as more than 0 times and less than 0.5 times the diameter of the Litz wire used to wind the coil, while the turn spacing of the loosely wound portion is defined as greater than 0.5 times and less than or equal to 2 times the diameter of the Litz wire used to wind the coil. The magnetic field distribution is optimized by the ratio of the turn spacing to the diameter of the Litz wire, thereby improving the anti-deflection effect.

[0076] In this embodiment of the invention, a square coil with various winding methods is used as the basis. The asymmetrical coil relationship between the outer square transmitting coil 1 and the square receiving coil 7, as well as the strong and weak magnetic field relationship between the middle square transmitting coil and the inner square transmitting coil 6, are combined. The structure and manufacturing are simple and can achieve good anti-offset effect. This method of optimizing the magnetic field distribution in a purely passive manner simplifies the structure and reduces the cost of the system level. It enables the system to maintain low mutual inductance fluctuation rate and high system transmission efficiency of wireless power transmission system under large positional offset without adding complex circuits.

[0077] Please see Figure 4 The second embodiment of the present invention provides a parameter design method for an anti-offset wireless power transfer magnetic coupling mechanism, comprising:

[0078] Step 101: Based on the mutual inductance expression based on vector magnetic potential, determine the first target coil parameters when the external receiving head-on mutual inductance between the outer square transmitting coil and the square receiving coil is greater than or equal to the preset minimum mutual inductance value and the external receiving head-on mutual inductance is at its maximum. The first target coil parameters include the outer side length, number of turns and turn spacing of the outer square transmitting coil, as well as the outer side length, number of turns and turn spacing of the square receiving coil.

[0079] Step 102: Based on the mutual inductance expression and the parameters of the first target coil, offset the square receiving coil along the X-axis, Y-axis and Z-axis respectively, construct the corresponding axis offset mutual inductance curves and determine the associated axis offset mutual inductance complementary curves.

[0080] Step 103: Based on the parameters of the first target coil and the mutual inductance expression, determine the mutual inductance between the square transmitting coil and the inner square transmitting coil and the square receiving coil in the four groups, and use the mutual inductance between the inner square transmitting coil and the square receiving coil to determine the axial offset mutual inductance complementary incremental curve of each axis offset mutual inductance complementary curve.

[0081] Step 104: Based on the parameters of the first target coil and the mutual inductance expression, determine the in-center receiving offset mutual inductance corresponding to each offset of the square receiving coil along the X-axis, Y-axis and Z-axis respectively. Extract the incremental mutual inductance corresponding to each offset from the complementary incremental curve of the offset mutual inductance of each axis and determine the corresponding mutual inductance offset range. Determine the maximum offset of the in-center receiving offset mutual inductance within its respective mutual inductance offset range and add them together to output the combined offset.

[0082] Step 105: Determine the second target coil parameters corresponding to the maximum combined offset. The second target coil parameters include the outer side length, number of turns, and turn spacing of the middle square transmitting coil, as well as the outer side length, number of turns, and turn spacing of the inner square transmitting coil.

[0083] It should be noted that this embodiment considers using a mutual inductance expression based on vector magnetic potential to calculate the mutual inductance between the transmitting coil and the receiving coil. This mutual inductance expression can be used to calculate the mutual inductance between multi-turn transmitting coils and multi-turn receiving coils in non-coaxial cases. To better illustrate the coil parameter optimization process, a simulation example is provided:

[0084] With the geometric center of the transmitting coil assembly as the origin According to the plane where the transmitting coil group is located Establish XYZ coordinate axes;

[0085] Taking Litz wire winding as an example, the initial diameter of the Litz wire is... For example, such as 2mm; initialize the outer square transmitting coil's outer side length optimization range, outer side length optimization step size, coil number of turns optimization range, coil number of turns optimization step size, turn spacing optimization range, and turn spacing optimization step size; initialize the square receiving coil's outer side length optimization range, outer side length optimization step size, coil number of turns optimization range, coil number of turns optimization step size, turn spacing optimization range, and turn spacing optimization step size, the square receiving coil includes an outer receiving coil and an inner receiving coil;

[0086] Given any combination of the first coil parameters of the outer square transmitting coil and the square receiving coil, the mutual inductance when the outer square transmitting coil and the square receiving coil are directly opposite each other, i.e., the mutual inductance when the outer square transmitting coil and the square receiving coil are directly opposite each other, is determined based on the mutual inductance expression. ,like Greater than or equal to (If a minimum mutual inductance value is preset), then the coil parameter combination is retained, and through iterative calculations, a value that satisfies the minimum mutual inductance value is found. Greater than or equal to And make The largest combination of first coil parameters is taken as the first target coil parameter, which serves as the result of parameter optimization for the outer square transmitting coil and the square receiving coil. The first target coil parameter includes the outer side length of the outer square transmitting coil. Number of coil turns The turn spacing and the outer side length of the square receiving coil. The number of coil turns and the turn spacing; the number of coil turns for a square receiving coil includes the number of coil turns of the outer receiving coil. and the number of turns of the internal receiving coil The turn spacing of the square receiving coil includes the turn spacing of the outer receiving coil and the turn spacing of the inner receiving coil; it can be understood that when any All less than If the set parameters are deemed unreasonable within the optimization range, they need to be adjusted and re-optimized.

[0087] Under the coil parameters of the first target coil, the square receiving coil is offset by a certain distance (offset) along the X, Y, and Z axes respectively. Based on the mutual inductance expression, the offset mutual inductance between the outer square transmitting coil and the square receiving coil for each offset is calculated. Axial offset mutual inductance curves are then constructed sequentially for offsets along the X, Y, and Z axes, including the X-axis offset mutual inductance curve. Y-axis offset mutual inductance curve Mutual inductance curve with Z-axis offset This leads to the corresponding complementary curves of axial offset mutual inductance, including the complementary curve of X-axis offset mutual inductance. Y-axis offset mutual inductance complementary curve Complementary curves of mutual inductance and Z-axis offset That is, for any X-axis offset, the following condition is met. The same applies to the Y-axis and Z-axis;

[0088] The coil parameters of the square transmitting coil are the same. Initialize the optimization range, optimization step size, coil number of turns, coil number of turns optimization step size, turn spacing optimization range, and turn spacing optimization step size of the square transmitting coil. The square transmitting coil includes an outer transmitting coil and an inner transmitting coil. Initialize the optimization range, optimization step size, coil number of turns, coil number of turns optimization step size, turn spacing optimization range, and turn spacing optimization step size of the inner square transmitting coil.

[0089] Given any combination of the second coil parameters of the central square transmitting coil and the inner square transmitting coil, the mutual inductance when the central square transmitting coil and the inner square transmitting coil are directly opposite the square receiving coil is determined based on the mutual inductance expression. This mutual inductance is the central-inner receiving coil directly opposite each other. Using the mutual inductance of the receiving end as an increment, the axis offset mutual inductance complementary curve is shifted upwards. The corresponding axial offset mutual inductance complementary incremental curves are obtained, including the X-axis offset mutual inductance complementary incremental curve. Y-axis offset mutual inductance complementary incremental curve complementary incremental curve of mutual inductance and Z-axis offset The mutual inductance expression is used to determine the mutual inductance between the central square transmitting coil and the inner square transmitting coil and the square receiving coil when the square receiving coil is offset by different amounts along the X-axis; that is, the central-inner receiving offset mutual inductance along the X-axis. Based on the incremental mutual inductance of the same offset in the complementary incremental curve of the X-axis offset mutual inductance, the associated mutual inductance offset range is determined. For example... If the mutual inductance is within ±5% of the X-axis offset mutual inductance complementary increment curve, then the result is retained until it is recorded that satisfies the condition. The maximum offset along the X-axis in the internal receiving offset mutual inductance Similarly, determine the mutual inductance of the in-center receiver offset along the Y-axis when the square receiving coil is offset by different amounts. If the associated mutual inductance offset range is satisfied, for example... If the mutual inductance is within ±5% of the incremental curve of mutual inductance offset along the Y-axis, then the result is retained until it is recorded that satisfies the condition. The maximum offset along the Y-axis in the internal receiving offset mutual inductance Similarly, the mutual inductance of the in-center receiver offset along the Z-axis satisfies the associated mutual inductance offset range when the square receiving coil is offset by different amounts along the Z-axis, for example... If the mutual inductance is within ±5% of the Z-axis offset mutual inductance complementary increment curve, then the result is retained until it is recorded that satisfies the condition. The maximum offset along the Z-axis in the internal receiving offset mutual inductance Let the combined offset under any combination of second coil parameters be . ;

[0090] Through iterative calculations, it is determined whether the mutual inductance of the receiving offset within the specified range is satisfied and whether the mutual inductance is within the specified range. The largest combination of second coil parameters is the second target coil parameter, which includes the outer side length of the square transmitting coil. The number of coil turns and the turn spacing, as well as the outer side length of the inner square transmitting coil. Number of coil turns The number of turns of the central square transmitting coil includes the number of turns of the outer transmitting coil, along with the turn spacing. and the number of turns of the internal transmitting coil The turn spacing of the square transmitting coil includes the turn spacing of the outer transmitting coil and the turn spacing of the inner transmitting coil;

[0091] Understandably, to avoid situations where the outer side length, number of turns, and turn spacing of any coil cannot be matched in the first or second coil parameter combination (e.g., the combination of coil turns and turn spacing cannot match the corresponding outer side length), a first coil parameter constraint is set for the traversal parameters of single-wound coils (i.e., outer square transmitting coil and inner square transmitting coil), and a second coil parameter constraint is set for the traversal parameters of coils with a loose inner and tight outer shape (i.e., middle square transmitting coil and square receiving coil). The first coil parameter constraint includes "[wire diameter * number of coil turns + (number of coil turns - 1) * turn spacing] - 1 > outer side length of coil / 2", and the second coil parameter constraint includes "[wire diameter * number of turns of outer coil + (number of turns of outer coil - 1) * turn spacing of outer coil] + number of turns of inner coil * (turn spacing of inner coil + wire diameter * number of turns of outer coil) ... The outer coil includes an outer transmitting coil and an outer receiving coil, and the inner coil includes an inner transmitting coil and an inner receiving coil. Specifically, the square transmitting coil must satisfy "[wire diameter * number of turns of the outer transmitting coil + (number of turns of the outer transmitting coil - 1) * turn spacing of the outer transmitting coil] + number of turns of the inner transmitting coil * (turn spacing of the inner transmitting coil + wire diameter) - 1 > outer side length of the coil / 2". The square receiving coil must satisfy "[wire diameter * number of turns of the outer receiving coil + (number of turns of the outer receiving coil - 1) * turn spacing of the outer coil] + number of turns of the inner receiving coil * (turn spacing of the inner receiving coil + wire diameter) - 1 > outer side length of the coil / 2". When the coil parameter constraints are not met in the first or second coil parameter combination, the current loop is exited and the previous loop is returned to continue the next parameter iteration.

[0092] In one specific implementation of this embodiment, a mutual inductance expression is constructed based on vector magnetic potential and two-dimensional Fourier transform:

[0093] First, a compensation network analysis of the coupling mechanism of the wireless power transmission system is performed using a mutual inductance model based on the law of electromagnetic induction. In the circuit equivalent, parasitic parameters of the devices are ignored, simplifying them to ideal devices. Figure 5 The wireless power transmission system shown is obtained Figure 6 The equivalent circuit of mutual inductance in an LCC-S type compensation network is shown, wherein, The resonant inductor is the high-frequency square wave voltage source output by the inverter circuit. ,capacitance ,capacitance and capacitors Forming an LCC-S type compensation network, and Characterizing the mutual inductance coupling effect of the coupling mechanism;

[0094] based on Figure 6 The equivalent circuit is obtained, and Kirchhoff's Voltage Law (KVL) equations are established for the three independent loops of the system:

[0095] (1)

[0096] In the formula, This represents the high-frequency square wave voltage source output by the inverter circuit. Indicates the input current of the compensation network. Represents the imaginary unit. Represents angular frequency. Indicates compensation inductance, This represents the first compensation capacitor at the transmitting end. Indicates the output current of the transmitting end. Indicates mutual intuition. Indicates the receiving end current. This refers to the second compensation capacitor at the transmitting end. Indicates the self-inductance of the transmitting coil. This indicates the self-inductance of the receiving coil. This indicates the compensation capacitor at the receiving end. Indicates the equivalent load impedance;

[0097] If the resonant frequency of the system compensation network is set to be the same as the switching frequency of the inverter circuit, then the parameters of the compensation networks at the transmitting and receiving ends must satisfy the following:

[0098] (2)

[0099] Substituting equation (1) into equation (2), we can obtain the expressions for the currents of the compensation network:

[0100] (3)

[0101] According to Ohm's law, the system output voltage expression is derived from equation (3), and the system voltage gain is obtained:

[0102] (4)

[0103] (5)

[0104] In the formula, Indicates the output voltage. Indicates voltage gain;

[0105] Equation (5) shows that, neglecting parasitic parameters, the voltage gain Mutual induction They are positively correlated. Because... The system parameters are kept constant after design, and are fixed when the input voltage is stable and the coupling mechanism is not offset. This value ensures the load-independent characteristic of the system output voltage when coupling mechanism misalignment occurs. The attenuation of the value will directly lead to a decrease in the output voltage. Therefore, based on this property, the fitting parameter design method in this embodiment designs a mutual inductance expression:

[0106] See Figure 7 As shown, with the center of the transmitting coil as the origin and the plane containing the transmitting coil as the plane, Establish the XYZ coordinate axes, based on the transmitting coil The center of the coil and the receiving coil The coaxial vertical distance between the centers of the coils Division Area 1 Area 2 and Area 3, Indicates the transmitting coil Half the length, Indicates the transmitting coil half the width, Indicates receiving coil Half the length, Indicates receiving coil half the width, , , , These represent the sides of the transmitting coil. , , , These represent the sides of the receiving coil. Indicates flow The current;

[0107] Set any point in space Its vector magnetic potential expression is:

[0108] (6)

[0109] In the formula, Indicates the coordinates of the observation point. This represents the vector magnetic potential of the observation point in the spatial domain. Represents the permeability of free space. Represents pi (π). Indicates the coordinates of the source point (the location of the current element in the transmitting coil). Indicates current density, This indicates the current distribution region of the transmitting coil. This represents a volume element at the source point. The distance vector from the source point to the observation point is expressed as:

[0110] (7)

[0111] In the formula, This represents the distance vector from the source point to the observation point. This represents the X-axis, Y-axis, and Z-axis coordinates of the observation point. Representing the X-axis, Y-axis, and Z-axis coordinates of the source point, Represents the unit vector in the X-axis direction. Represents the unit vector in the Y-axis direction. Represents the unit vector along the Z-axis;

[0112] To solve equation (6), we introduce the two-dimensional Fourier transform and its inverse transform:

[0113] (8)

[0114] (9)

[0115] In the formula, This represents the vector magnetic potential of the observation point in the spatial frequency domain. Spatial frequency domain coordinates representing the X-axis coordinates. The spatial frequency domain coordinates representing the Y-axis coordinates. This represents the vector magnetic potential of the observation point in the spatial domain. Represents the natural constant. Represents the imaginary unit. This represents the X-axis, Y-axis, and Z-axis coordinates of the observation point. Represents pi;

[0116] From equations (6) and (8), the expression for vector magnetic potential can be obtained as follows:

[0117] (10)

[0118] in, Indicates the transverse spatial wavenumber modulus. ;

[0119] Incident magnetic flux density The vector magnetic potential of the incident magnetic field can be determined by... express:

[0120] (11)

[0121] In the formula, Describes the differential operator. Let curl operator be represented; from equation (11), we can obtain:

[0122] (12)

[0123] In the formula, Represents the incident magnetic flux density In the spatial domain, the X-axis component, Y-axis component, and Z-axis component... Indicates vector magnetic potential In the spatial domain, the X-axis component, Y-axis component, and Z-axis component... This represents partial derivative operations; based on equation (12), a two-dimensional Fourier transform can be performed to obtain:

[0124] (13)

[0125] In the formula, Represents the incident magnetic flux density The X-axis, Y-axis, and Z-axis components in the spatial frequency domain This represents the two-dimensional Fourier transform operation. The X-axis component represents the vector magnetic potential contributed by a current parallel to the X-axis direction. The Y-axis component represents the vector magnetic potential contributed by a current parallel to the Y-axis direction. The Z-axis component represents the vector magnetic potential contributed by a current parallel to the Z-axis direction. Figure 7 It can be known Since there is no relevant current component, the value is zero. Therefore, equation (13) can be transformed into:

[0126] (14)

[0127] Considering Figure 7 The current distribution of the conductor parallel to the X-axis satisfies... Since there are two wires parallel to the X-axis, therefore... and These two Similarly, the first and second components also have... First component and The second component :

[0128] (15)

[0129] (16)

[0130] Substituting equations (15) and (16) into equation (14), we get:

[0131] (17)

[0132] (18)

[0133] In the formula, This represents the coefficient of the incident magnetic field along the X-axis in the spatial frequency domain. This represents the coefficient of the incident magnetic field along the Y-axis in the spatial frequency domain. This represents the coefficient of the incident magnetic field along the Z-axis in the spatial frequency domain; from equations (17) and (18), we can see that:

[0134] (19)

[0135] The reflected magnetic flux density satisfies the following equation:

[0136] (20)

[0137] (twenty one)

[0138] (twenty two)

[0139] In the formula, Represents the reflected magnetic flux density. Represents the Laplace operator. Denotes the divergence operator, Let curl operator be denoted; performing a two-dimensional Fourier transform on equations (19) and (20) yields:

[0140] (twenty three)

[0141] (twenty four)

[0142] In the formula, Represents the reflected magnetic flux density The X-axis component, Y-axis component, and Z-axis component in the spatial frequency domain; from equations (22)-(24), we know that:

[0143] (25)

[0144] (26)

[0145] For region 1 ( ) and Area 3 ( Its relative permeability , The conductivity is a constant. The magnetic flux density in these two regions satisfy:

[0146] (27)

[0147] (28)

[0148] Performing a two-dimensional Fourier transform on equations (27) and (28), we obtain:

[0149] (29)

[0150] (30)

[0151] In the formula, Represents the magnetic flux density in the spatial frequency domain. Represents magnetic flux density The X-axis, Y-axis, and Z-axis components in the spatial frequency domain; and Substituting into equation (29), we get:

[0152] (31)

[0153] because Z-axis component of current density Then we can obtain:

[0154] (32)

[0155] From equations (30) and (32), we can obtain

[0156] (33)

[0157] Because the excitation coil is located flat, Magnetic flux density The Z-axis component is continuous in the plane, and the magnetic field strength is... The X-axis component is discontinuous in the plane. hour Z-axis components and If the X-axis component is continuous in the plane, then:

[0158] when When applying the boundary conditions to the reflection field alone, we can obtain:

[0159] (34)

[0160] In the formula, This represents the Z-axis component of the magnetic flux density in region 1 of the reflected field in the spatial frequency domain. This represents the X-axis component of the magnetic flux density in region 1 of the reflected field in the spatial frequency domain;

[0161] when At that time, we can obtain:

[0162] (35)

[0163] In the formula, This represents the Z-axis component of the magnetic flux density in region 3 in the spatial frequency domain. The X-axis component of the magnetic flux density in region 3 is represented in the spatial frequency domain.

[0164] For equations (23) and (31), the general solution is:

[0165] (36)

[0166] In the formula, Indicates a region index. The values ​​are 1, 3 and , Represents the reflected field. Represents the exponential growth term along the Z-axis. The weighting coefficients, Represents the exponentially decaying term along the Z-axis. Weighting coefficients;

[0167] Due to area 1 As the magnetic flux density in region 1 approaches negative infinity, the Z-axis component in the spatial frequency domain... It should be 0, then Due to area 3 When it approaches infinity, It should be 0, then Therefore, we can conclude that:

[0168] (37)

[0169] In the formula, This represents the weighting coefficient of the exponentially increasing term of the reflected magnetic field along the Z-axis in the spatial frequency domain. This represents the weighting coefficient of the exponential decay term of the reflected magnetic field along the Z-axis in the spatial frequency domain. This represents the weighting coefficient of the exponentially growing term along the Z-axis in region 1 of the reflected field in the spatial frequency domain. This represents the weighting coefficient of the exponential attenuation term of region 3 in the reflected field along the Z-axis in the spatial frequency domain;

[0170] From equations (19), (26), (33)-(36), we can obtain:

[0171] (38)

[0172] Based on equation (38), we can obtain:

[0173] (39)

[0174] In the formula, Represents the reflection coefficient. Represents relative permeability; based on equation (39), we can obtain:

[0175] (40)

[0176] By applying the two-dimensional inverse Fourier transform, the Z-axis component of the magnetic flux density can be obtained. for:

[0177] (41)

[0178] Therefore, the mutual inductance expression for both the transmitting and receiving coils being single-turn rectangular coils is as follows:

[0179] (42)

[0180] In the formula, Indicates mutual intuition. This indicates the integration region of the receiving coil. This represents the vector differential line element along the integration path. This represents the offset distance of the receiving coil's center relative to the transmitting coil's center along the X-axis. This indicates the offset distance of the receiving coil center relative to the transmitting coil center along the Y-axis.

[0181] Therefore, the first square transmitting coil The first turn of the coil and the square receiving coil The expressions for the mutual inductance of coils include:

[0182] (43)

[0183] (44)

[0184] (45)

[0185] (46)

[0186] (47)

[0187] (48)

[0188] In the formula, Indicates the first of the transmitting coils The first turn of the coil and the receiving coil Mutual inductance of the coils Represents pi (π). Indicates the first of the transmitting coils The current in the coil, This represents the offset distance of the receiving coil's center relative to the transmitting coil's center along the X-axis. This represents the offset distance of the receiving coil's center relative to the transmitting coil's center along the Y-axis. Indicates the receiving coil number The outer half-width of the coil Indicates the receiving coil number The outer half length of the coil This indicates the radius of the wire used to wind the coil. Represents the natural constant. Represents the imaginary unit. Spatial frequency domain coordinates representing the X-axis coordinates. The spatial frequency domain coordinates representing the Y-axis coordinates. Indicates the transverse spatial wavenumber modulus. This represents the coaxial perpendicular distance between the centers of the transmitting coil and the receiving coil. This represents the coefficient of the incident magnetic field along the Z-axis in the spatial frequency domain. This represents the weighting coefficient of the exponentially increasing term of the reflected magnetic field along the Z-axis in the spatial frequency domain. This represents the weighting coefficient of the exponential decay term of the reflected magnetic field along the Z-axis in the spatial frequency domain. Represents the permeability of free space. Indicates the first of the transmitting coils The outer half length of the coil Indicates the first of the transmitting coils The outer half-width of the coil This represents the relative permeability (between region 1 and region 3). Indicates the reflection coefficient;

[0189] Therefore, the mutual inductance expression between multiple transmitting coils and a single receiving coil is:

[0190] (49)

[0191] In the formula, Indicates mutual intuition. Indicates the first One transmitting coil, Indicates the number of transmitting coils. Indicates the first One transmitting coil With receiving coil Mutual intuition between them This indicates the number of coil turns for each transmitting coil. This indicates the number of coil turns for each receiving coil. Indicates the first coil, Indicates the first coil, Indicates the first The first transmitting coil The first turn of the coil and the receiving coil Mutual inductance between coils.

[0192] This implementation also conducts simulation experiments on the above parameter design method: the initial Litz wire diameter is 2mm; for the outer square transmitting coil, the optimization range for the outer side length of the coil is 260mm-320mm, the optimization step size for the outer side length of the coil is 10mm, the optimization range for the number of coil turns is 6-10 turns, the optimization step size for the number of coil turns is 1 turn, and the optimization range for the turn spacing is 0mm-1mm, with a turn spacing optimization step size of 1mm; for the square receiving coil, the optimization range for the outer side length of the coil is 60mm-120mm, the outer side length of the coil... The optimization step size is 10mm. The optimization range for the number of turns of the inner receiving coil is 7-11 turns, with a step size of 1 turn. The optimization range for the turn spacing of the inner receiving coil is 2mm-4mm, with a step size of 1mm. The optimization range for the number of turns of the outer receiving coil is 2-6 turns, with a step size of 1 turn. The optimization range for the turn spacing of the outer receiving coil is 0mm-1mm, with a step size of 1mm. For the square transmitting coil, the optimization range for the outer side length is 40mm-90mm, with an optimization step size of 10mm. The optimization range for the number of turns in the inner transmitting coil is 7-11 turns, with an optimization step size of 1 turn. The optimization range for the turn spacing in the inner transmitting coil is 2mm-4mm, with an optimization step size of 1mm. The optimization range for the number of turns in the outer transmitting coil is 2-6 turns, with an optimization step size of 1 turn. The optimization range for the turn spacing of the outer transmitting coil is 0mm-1mm, and the optimization step size for the turn spacing of the outer transmitting coil is 1mm. For the inner square transmitting coil, the optimization range for the outer side length is 100mm-160mm, and the optimization step size for the outer side length is 10mm. The optimization range for the number of turns is 3-7 turns, and the optimization step size for the number of turns is 1 turn. The optimization range for the turn spacing is 2mm-4mm, and the optimization step size for the turn spacing is 1mm. The simulation results obtained through the aforementioned step-by-step parameter optimization process for the main and auxiliary coils are shown in Table 1 and... Figure 8 As shown, the mutual inductance fluctuation rate can be controlled within ±5%, thus achieving constant voltage output. Understandably, this optimization process could be implemented using MATLAB code for iterative calculations.

[0193] Table 1 Parameters of the optimized magnetic coupling mechanism

[0194]

[0195] In this embodiment of the invention, the optimization process considers a global optimization search of the three-axis offset distance. Combined with a step-by-step configuration of the main and auxiliary coils, the curse of dimensionality in simultaneous optimization of multiple parameters is avoided. A strategy of prioritizing main coils over auxiliary coils (i.e., the outer square transmitting coil and square receiving coil are the main coils, while the four sets of middle square transmitting coils and inner square transmitting coils are auxiliary coils) is adopted. Simultaneously, mutual inductance curves, mutual inductance complementary curves, and mutual inductance complementary incremental curves are introduced as analytical tools. This maps the abstract spatial magnetic field distribution into a visualized mutual inductance characteristic curve, achieving a quantitative characterization of the magnetic field coupling capability. Furthermore, by observing the mutual inductance complementary incremental curves, the magnetic field distribution of the required coils can be quickly diagnosed, thus facilitating subsequent adjustment of the transmitting coil dimensions. The selection of the number of turns provides guidance, avoiding the drawbacks of blind trial and error in traditional design, and helps to quickly and reliably optimize the magnetic coupling structure with strong anti-offset characteristics. In addition, a mutual inductance expression for multi-turn transmitting coils and multi-turn receiving coils in non-coaxial cases based on vector magnetic potential and two-dimensional Fourier transform is proposed. Based on this mutual inductance expression, the coil parameters of the transmitting coil and receiving coil in the proposed magnetic coupling structure are iteratively optimized, which helps to reduce the simulation workload and achieve better optimization results, thus achieving strong anti-offset effect. At the same time, the mutual inductance formula can quantify the mutual inductance between any two turns of the multi-turn transmitting coil and any two turns of the multi-turn receiving coil, which helps to monitor abnormal data.

[0196] Please see Figure 9 The third embodiment of the present invention provides a parameter design device for an anti-offset wireless power transfer magnetic coupling mechanism, comprising:

[0197] The first parameter optimization module 901 is used to determine the first target coil parameters when the external receiving head-on mutual inductance between the outer square transmitting coil and the square receiving coil is greater than or equal to a preset minimum mutual inductance value and the external receiving head-on mutual inductance is at its maximum, based on the mutual inductance expression based on vector magnetic potential. The first target coil parameters include the outer side length, number of coil turns and turn spacing of the outer square transmitting coil, as well as the outer side length, number of coil turns and turn spacing of the square receiving coil.

[0198] The offset curve construction module 902 is used to offset the square receiving coil along the X-axis, Y-axis and Z-axis respectively based on the mutual inductance expression and the parameters of the first target coil, construct the corresponding axis offset mutual inductance curves and determine the associated axis offset mutual inductance complementary curves.

[0199] The offset curve adjustment module 903 is used to determine the mutual inductance between the square transmitting coil and the inner square transmitting coil and the square receiving coil in four groups based on the first target coil parameters and mutual inductance expression, and to determine the axial offset mutual inductance complementary incremental curve of each axial offset mutual inductance complementary curve using the mutual inductance between the square transmitting coil and the inner square transmitting coil.

[0200] The offset determination module 904 is used to determine the in-middle receiving offset mutual inductance corresponding to each offset of the square receiving coil along the X-axis, Y-axis and Z-axis respectively, based on the first target coil parameters and mutual inductance expression; extract the incremental mutual inductance corresponding to each offset from the complementary incremental curve of mutual inductance of each axis offset and determine the corresponding mutual inductance offset range; determine the maximum offset of the in-middle receiving offset mutual inductance within its respective mutual inductance offset range and add them together to output the combined offset.

[0201] The second parameter optimization module 905 is used to determine the second target coil parameters corresponding to the maximum combined offset. The second target coil parameters include the outer side length, number of turns and turn spacing of the middle square transmitting coil, and the outer side length, number of turns and turn spacing of the inner square transmitting coil.

[0202] The outer square transmitting coil and the inner square transmitting coil both satisfy the first coil parameter constraint, which includes [wire diameter * number of coil turns + (number of coil turns - 1) * turn spacing] - 1 > outer side length of coil / 2. The middle square transmitting coil and the square receiving coil both satisfy the second coil parameter constraint, which includes [wire diameter * number of turns of outer coil + (number of turns of outer coil - 1) * turn spacing of outer coil] + number of turns of inner coil * (turn spacing of inner coil + wire diameter) - 1 > outer side length of coil / 2.

[0203] Embodiment 3 of the present invention also provides a computer device, including a memory and a processor, wherein the memory stores a computer program; when the computer program is executed by the processor, the processor performs the steps of the parameter design method for the anti-offset wireless power transmission magnetic coupling mechanism as described in Embodiment 2 of the present invention.

[0204] Embodiment 4 of the present invention also provides a computer-readable storage medium storing a computer program / instruction thereon, which, when executed by a processor, implements the steps of the parameter design method for the anti-offset wireless power transfer magnetic coupling mechanism as described in Embodiment 2 of the present invention.

[0205] Embodiment 5 of the present invention also provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the steps of the parameter design method for the anti-offset wireless power transmission magnetic coupling mechanism as described in Embodiment 2 of the present invention.

[0206] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the above-described device and module can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0207] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0208] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0209] Furthermore, the functional modules in the various embodiments of the present invention can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0210] If the integrated module is implemented as a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0211] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A deflection-resistant wireless power transfer magnetic coupling mechanism, characterized in that, It includes a coupled transmitting coil group and a square receiving coil; The transmitting coil group includes an outer square transmitting coil connected in series, four groups of middle square transmitting coils, and an inner square transmitting coil. The four sets of central square transmitting coils are distributed around the square side circumference of the inner square transmitting coil; The four sets of middle square transmitting coils and the inner square transmitting coils are located inside the outer square transmitting coil. The coil center of the outer square transmitting coil, the geometric center of the four sets of middle square transmitting coils, and the coil center of the inner square transmitting coil coincide. The outer square transmitting coil and the square receiving coil are asymmetrical coils; The magnetic field of the middle square transmitting coil is stronger than that of the inner square transmitting coil; The square transmitting coil includes an outer transmitting coil and an inner transmitting coil, and the square receiving coil includes an outer receiving coil and an inner receiving coil; The outer square transmitting coil, the outer transmitting coil, and the outer receiving coil are compact coils, while the inner square transmitting coil, the inner transmitting coil, and the inner receiving coil are loose coils.

2. The anti-deflection wireless power transfer magnetic coupling mechanism according to claim 1, characterized in that, The offset distance between the center of the middle square transmitting coil and the center of the inner square transmitting coil is 0.395 * the inner side length of the outer square transmitting coil + 0.105 * the outer side length of the inner square transmitting coil.

3. The anti-deflection wireless power transfer magnetic coupling mechanism according to claim 1, characterized in that, The outer side length of the inner square transmitting coil is greater than the outer side length of the middle square transmitting coil; The inner square transmitting coil has fewer turns than the middle square transmitting coil.

4. The anti-deflection wireless power transfer magnetic coupling mechanism according to claim 1, characterized in that, The ratio of the turn spacing to the wire diameter of the compact coil is: The ratio of the turn spacing to the wire diameter of the loose coil is... .

5. A parameter design method for an anti-offset wireless power transfer magnetic coupling mechanism, characterized in that, include: Based on the mutual inductance expression based on vector magnetic potential, the parameters of the first target coil are determined when the external receiving mutual inductance between the outer square transmitting coil and the square receiving coil is greater than or equal to the preset minimum mutual inductance value and the external receiving mutual inductance is at its maximum. The parameters of the first target coil include the outer side length, number of turns and turn spacing of the outer square transmitting coil, as well as the outer side length, number of turns and turn spacing of the square receiving coil. Based on the mutual inductance expression and the parameters of the first target coil, the square receiving coil is offset along the X-axis, Y-axis and Z-axis respectively, and the corresponding axis offset mutual inductance curves are constructed and the associated axis offset mutual inductance complementary curves are determined. Based on the first target coil parameters and the mutual inductance expression, the mutual inductance between the square transmitting coil and the inner square transmitting coil and the square receiving coil in the four groups is determined, and the mutual inductance between the inner square transmitting coil and the square receiving coil is determined using the mutual inductance between the inner square receiving coil and the square receiving coil. The mutual inductance between the inner square receiving coil and the square receiving coil is used to determine the complementary curve of ... Based on the first target coil parameters and the mutual inductance expression, the in-center receiving offset mutual inductance corresponding to each offset of the square receiving coil along the X-axis, Y-axis and Z-axis is determined. The incremental mutual inductance corresponding to each offset is extracted from the complementary incremental curve of the mutual inductance of each axis offset and the corresponding mutual inductance offset range is determined. The maximum offset of the in-center receiving offset mutual inductance within its respective mutual inductance offset range is determined and the combined offset is output. Determine the second target coil parameters corresponding to the maximum combined offset. The second target coil parameters include the outer side length, number of turns, and turn spacing of the middle square transmitting coil, as well as the outer side length, number of turns, and turn spacing of the inner square transmitting coil. The outer square transmitting coil and the inner square transmitting coil both satisfy the first coil parameter constraint, which includes [wire diameter * number of coil turns + (number of coil turns - 1) * turn spacing] - 1 > outer side length of coil / 2. The middle square transmitting coil and the square receiving coil both satisfy the second coil parameter constraint, which includes [wire diameter * number of turns of outer coil + (number of turns of outer coil - 1) * turn spacing of outer coil] + number of turns of inner coil * (turn spacing of inner coil + wire diameter) - 1 > outer side length of coil / 2.

6. The parameter design method for the offset wireless power transfer magnetic coupling mechanism according to claim 5, characterized in that, Mutual inductance expressions, including: ； ； ； ； ； ； ； In the formula, Indicates mutual intuition. Indicates the first One transmitting coil, Indicates the number of transmitting coils. Indicates the first One transmitting coil With receiving coil Mutual intuition between them This indicates the number of coil turns for each transmitting coil. This indicates the number of coil turns for each receiving coil. Indicates the first coil, Indicates the first coil, Indicates the first The first transmitting coil The first turn of the coil and the receiving coil Mutual inductance between coils Indicates the first of the transmitting coils The first turn of the coil and the receiving coil Mutual inductance of the coils Represents pi (π). Indicates the first of the transmitting coils The current in the coil, This represents the offset distance of the receiving coil's center relative to the transmitting coil's center along the X-axis. This represents the offset distance of the receiving coil's center relative to the transmitting coil's center along the Y-axis. Indicates the receiving coil number The outer half-width of the coil Indicates the receiving coil number The outer half length of the coil This indicates the radius of the wire used to wind the coil. Represents the natural constant. Represents the imaginary unit. Spatial frequency domain coordinates representing the X-axis coordinates. The spatial frequency domain coordinates representing the Y-axis coordinates. Indicates the transverse spatial wavenumber modulus. This represents the coaxial perpendicular distance between the centers of the transmitting coil and the receiving coil. This represents the coefficient of the incident magnetic field along the Z-axis in the spatial frequency domain. This represents the weighting coefficient of the exponentially increasing term of the reflected magnetic field along the Z-axis in the spatial frequency domain. This represents the weighting coefficient of the exponential decay term of the reflected magnetic field along the Z-axis in the spatial frequency domain. Represents the permeability of free space. Indicates the first of the transmitting coils The outer half length of the coil Indicates the first of the transmitting coils The outer half-width of the coil Represents relative permeability. This represents the reflection coefficient.

7. A parameter design device for an anti-offset wireless power transfer magnetic coupling mechanism, characterized in that, include: The first parameter optimization module is used to determine the first target coil parameters when the external receiving head-on mutual inductance between the outer square transmitting coil and the square receiving coil is greater than or equal to a preset minimum mutual inductance value and the external receiving head-on mutual inductance is at its maximum, based on the mutual inductance expression based on vector magnetic potential. The first target coil parameters include the outer side length, number of coil turns and turn spacing of the outer square transmitting coil, as well as the outer side length, number of coil turns and turn spacing of the square receiving coil. The offset curve construction module is used to offset the square receiving coil along the X-axis, Y-axis and Z-axis respectively based on the mutual inductance expression and the parameters of the first target coil, construct the corresponding axis offset mutual inductance curves and determine the associated axis offset mutual inductance complementary curves. The offset curve adjustment module is used to determine the mutual inductance between the square transmitting coil and the inner square transmitting coil and the square receiving coil in four groups based on the first target coil parameters and the mutual inductance expression, and to determine the axial offset mutual inductance complementary incremental curve of each axial offset mutual inductance complementary curve using the mutual inductance between the square transmitting coil and the inner square transmitting coil. The offset determination module is used to determine the in-center receiving offset mutual inductance corresponding to each offset of the square receiving coil along the X-axis, Y-axis and Z-axis respectively, based on the first target coil parameters and the mutual inductance expression; extract the incremental mutual inductance corresponding to each offset from the complementary incremental curve of the mutual inductance of each axis offset and determine the corresponding mutual inductance offset range; determine the maximum offset of the in-center receiving offset mutual inductance within its respective mutual inductance offset range and add them together to output the combined offset. The second parameter optimization module is used to determine the second target coil parameters corresponding to the maximum combined offset. The second target coil parameters include the outer side length, number of turns and turn spacing of the middle square transmitting coil, as well as the outer side length, number of turns and turn spacing of the inner square transmitting coil. The outer square transmitting coil and the inner square transmitting coil both satisfy the first coil parameter constraint, which includes [wire diameter * number of coil turns + (number of coil turns - 1) * turn spacing] - 1 > outer side length of coil / 2. The middle square transmitting coil and the square receiving coil both satisfy the second coil parameter constraint, which includes [wire diameter * number of turns of outer coil + (number of turns of outer coil - 1) * turn spacing of outer coil] + number of turns of inner coil * (turn spacing of inner coil + wire diameter) - 1 > outer side length of coil / 2.

8. A computer device, characterized in that, It includes a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor causes the processor to perform the steps of the parameter design method for the anti-offset wireless power transfer magnetic coupling mechanism as described in any one of claims 5-6.

9. A computer-readable storage medium having a computer program / instructions stored thereon, characterized in that, When the computer program / instructions are executed by the processor, they implement the steps of the parameter design method for the anti-offset wireless power transfer magnetic coupling mechanism as described in any one of claims 5-6.

10. A computer program product comprising a computer program / instructions, characterized in that, When the computer program / instructions are executed by the processor, they implement the steps of the parameter design method for the anti-offset wireless power transfer magnetic coupling mechanism as described in any one of claims 5-6.

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