A chain type multi-section receiving wireless power transmission method suitable for a rotating shaft

Abstract

The application discloses a chain multi-section receiving wireless power transmission method suitable for a rotating shaft, relates to the field of wireless power transmission and electromagnetic field value, and comprises the following steps: determining the shaft diameter size, tailoring the chain receiving end according to the shaft diameter size, and installing the chain receiving end and the transmitting end on the rotating shaft; a two-dimensional subdomain model of the chain receiving end and the transmitting end is established, and coefficient solving is performed on the two-dimensional subdomain model; the two-dimensional subdomain model is corrected based on a 3D field, a two-dimensional result is equivalently mapped into three-dimensional magnetic flux density, and a mutual inductance M matrix of the chain receiving end and the transmitting end coil is obtained; based on the mutual inductance M matrix, the two-dimensional subdomain model is uniformly expressed under SP topology, and a capacitance setting is compensated; different working condition environments are simulated, robustness evaluation is performed on the chain receiving end and the transmitting end, and final voltage is output; and through the chain multi-section receiving and analytical modeling method, the wireless power transmission of the rotating shaft is realized to be fast in design, high in robustness and universal in compensation across shaft diameters.

Description

Technical Field

[0001] This invention relates to the fields of wireless power transmission and electromagnetic field numerical methods, and in particular to a chain-type multi-segment receiving wireless power transmission method suitable for rotating shafts. Background Technology

[0002] Rotary shaft equipment is affected by limited installation space and misalignment. Misalignment usually includes axial clearance, lateral offset and rotation angle.

[0003] In existing technologies, WPT design generally relies on repeated iterations of three-dimensional finite element methods, which results in high modeling and calculation costs. It is also difficult to form a rapid selection rule of "shaft diameter - number of coils - compensation parameters" in the early stages of the scheme. When the chain-type multi-segment receiving coils are arranged around the shaft, the coupling relationship between the segments and the transmitting coils and between the segments is intertwined. Traditional equivalent circuits are difficult to obtain a unified calculable expression of the load voltage and equivalent impedance.

[0004] Therefore, a chain-type multi-segment receiving wireless power transmission method suitable for rotating shafts is provided to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a chain-type multi-segment receiving wireless power transmission method suitable for rotating shafts. By constructing a two-dimensional analytical and three-dimensional corrected mutual inductance model and SP compensation topology, it achieves fast, unified, and robust design from shaft diameter to coil number to compensation capacitor, significantly reducing the modeling and iteration costs of rotating shafts.

[0006] To achieve the above objectives, the present invention provides a chain-type multi-segment receiving wireless power transmission method suitable for rotating shafts, comprising the following steps:

[0007] S1: Determine the shaft diameter, cut the chain receiver according to the shaft diameter, and install the chain receiver and transmitter on the rotating shaft;

[0008] S2: Establish a two-dimensional subdomain model of the chained receiver and transmitter, and solve for the coefficients of the two-dimensional subdomain model;

[0009] S3: Based on the 3D field, the two-dimensional subdomain model is corrected, and the two-dimensional result is equivalently mapped to the three-dimensional magnetic flux density to obtain the mutual inductance M matrix of the coils of the chain receiver and transmitter.

[0010] S4: Based on the mutual inductance M matrix, the model is uniformly expressed under the SP topology, and the compensation capacitor is tuned;

[0011] S5: Simulates different operating conditions to evaluate the robustness of the chain receiver and transmitter, and outputs the final voltage.

[0012] Preferably, in step S1, the chain receiver includes a receiver ferrite and a chain receiver coil disposed on the outer surface of the receiver ferrite. The receiver ferrite is nested with the rotating shaft, and an insulating sheet is disposed between the receiver ferrite and the rotating shaft. The transmitter is disposed at the bottom of the rotating shaft. The transmitter includes a transmitter ferrite and a transmitter coil disposed on the upper surface of the transmitter ferrite. The transmitter coil is disposed correspondingly to the chain receiver coil, and an air gap is disposed between the transmitter coil and the chain receiver coil.

[0013] Preferably, step S2 specifically includes the following steps:

[0014] S21: Establish a two-dimensional subdomain model of the chain receiver and transmitter, and divide the region based on the two-dimensional subdomain diagram;

[0015] S22: Divide the two-dimensional subdomain into regions , , , , , , , , , , , , , , , and The coefficients for different regions are solved separately.

[0016] S23: Solve for coefficients based on the boundary conditions of different regions.

[0017] Preferably, step S22 specifically includes the following steps:

[0018] Step 1: For the region Calculate two-dimensional Poisson using Maxwe11 Two-dimensional Poisson Specifically set as follows:

[0019] ;

[0020] ;

[0021] in, Represents the x-coordinate, Represents the coordinates in the vertical direction. Represents the permeability of free space. Indicates the region Relative permeability, Indicates the region Current density along the y-direction in a three-dimensional spatial field. Indicates the region The magnetic field strength vector;

[0022] Calculate two-dimensional Poisson general solution General solution Specifically set as follows:

[0023] ;

[0024] in, Indicates along Homogeneous solution components in the direction, Indicates along Homogeneous solution components in the direction, This represents the particular solution component generated by the current source excitation;

[0025] Two-dimensional Poisson analysis using the separation coefficient method By separating the variables, the general solution is obtained. General solution Specifically set as follows:

[0026] ;

[0027] in, Indicates the general solution equation along Solution function in coordinate direction, Indicates the general solution equation along Solution function in the coordinate direction;

[0028] Step 2: Area and region This is a passive region, area and region Current source For the passive region, the value is 0.

[0029] ;

[0030] ;

[0031] ;

[0032] in, Indicates the region Internal magnetic vector potential in The second derivative of the direction, Indicates the region Internal magnetic vector potential in The second derivative of the direction, Represents the constant of the separated variables. Representation and pattern number The corresponding eigenvalue parameters, Indicates the region Internal Spatial frequency of direction, This indicates the mode number, i.e., the spatial harmonic number. Indicates any region The upper boundary along the axial direction, Represents any region The lower boundary in the axial direction, Indicates the region The maximum mode order of the internal expansion, i.e., the maximum spatial harmonic number;

[0033] right Solving for the problem, we get:

[0034] ;

[0035] in, Indicates the solution of the separated variables in The direction is an undetermined coefficient, determined by the regional boundary conditions;

[0036] right Solving for the problem, we get:

[0037] ;

[0038] ;

[0039] ;

[0040] in, and Indicates the region The expansion coefficients of the inner m-th order mode in the z-direction. and Indicates the region Inner n-order mode in The expansion coefficient in the direction, Represents any region The upper boundary along the axial direction, Represents any region The lower boundary in the axial direction, and Indicates the region Spatial frequency within, and This indicates the mode number, i.e., the spatial harmonic number. Indicates the region Internal The maximum mode order in directional expansion, i.e., the maximum spatial harmonic number. Indicates the region Internal The maximum mode order of directional expansion;

[0041] Step 3: Area ,area ,area ,area ,area ,area and region For the air domain:

[0042] ;

[0043] ;

[0044] Step 4: Define skin depth By introducing the skin effect into the aluminum conductor region, the magnetic vector potential equation for the aluminum conductor region is obtained. The specific setting of the magnetic vector potential equation for the aluminum conductor region is as follows:

[0045] ;

[0046] ;

[0047] in, Indicates the region The magnetic vector potential within. Represents the imaginary unit. Represents angular frequency. Indicates electrical conductivity;

[0048] The magnetic vector potential equation for the aluminum conductor region was calculated, and the following was obtained:

[0049] ;

[0050] ;

[0051] in, and Indicates the corrected spatial frequency;

[0052] Step 5: Area ,area and region For the air region in contact with the ferrite or the rotating shaft:

[0053] ;

[0054] Step 6: For the region outer boundary Applying magnetic vector potential conditions Based on orthogonality, we obtain:

[0055] ;

[0056] .

[0057] Preferably, step S23 specifically includes the following steps:

[0058] Step 1: For the region ,area ,area and region The boundary conditions are:

[0059] ;

[0060] ;

[0061] in, and Indicates the region upper boundary place and The normal magnetic flux density component, and This represents the magnetic field boundary function at the boundary of different regions. and Indicates the region Adjacent region index set, Indicates the permeability of adjacent regions. and This represents the magnetic flux density components of adjacent regions at the boundary. and This represents the x-coordinate of the adjacent regions at the boundary. and Represented as a boundary indicator function, when When in region r, It is 1 if it is 1, otherwise it is 0. When the region is n, It is 1 if it is true, otherwise it is 0;

[0062] Step Two: For the region ,area ,area ,area ,area ,area and region On the four edges of the region, the adjacent domains Apply continuous vector potential and continuous tangential magnetic field matching across the entire segment, with the following boundary conditions:

[0063] ;

[0064] ;

[0065] ;

[0066] ;

[0067] in, Indicates the region upper boundary Magnetic vector potential at the location Indicates the region lower boundary Magnetic vector potential at the location Indicates the region Right boundary Magnetic vector potential at the location Indicates the region Left boundary The magnetic vector potential at the location;

[0068] Step 3: For the region ,area ,area ,area and region The boundary conditions are:

[0069] ;

[0070] ;

[0071] ;

[0072] ;

[0073] in, Indicates the region Right boundary The magnetic induction intensity in the normal direction at that location. This represents the permeability of region G2. Indicates that region G2 is at the boundary The magnetic induction intensity in the normal direction at that location. This represents the permeability of region G3. Indicates the region Left boundary Magnetic induction intensity in the normal direction at that location. Indicates that region G3 is at the boundary Magnetic induction intensity in the normal direction at the location;

[0074] Step 4: For any region and region Neighboring regions with the same magnetic vector potential The boundary conditions are:

[0075] ;

[0076] in, Represents any region and region Neighboring regions with the same magnetic vector potential The magnetic vector potential relation on the common boundary, Indicates the region The magnetic vector potential, Indicates the region The magnetic vector potential, Indicates the region homogeneous solution components, Indicates the region homogeneous solution components, Indicates the region The special solution, Indicates the region Special solution;

[0077] Step 5: Area For coil domain, region The particular solution is ,area With the region Adjacent, region For passive air domain, region The particular solution is 0, in the region For ferrite regions, region Both sides are passive regions. With the region Adjacent, region For air domain, region The particular solution is 0;

[0078] Step Six: Region-based With the region ,right The projection process is performed, and the projection principle is specifically set as follows:

[0079] ;

[0080] in, Indicates the function to be projected. Represents the projection function. Represents a function on an interval AND function The normalized integral result;

[0081] The corresponding algebraic equation is obtained, and the algebraic equation is specifically set as follows:

[0082] ;

[0083] ;

[0084] ;

[0085] ;

[0086] ;

[0087] ;

[0088] in, and and represent regions Inner expansion coefficient, and and represent regions Inner expansion coefficient, and The result of the function representing the projection operation. and This represents the weighted projection result. , , , , , These are basis functions for separating constants;

[0089] Step 7: Region-based With the region ,set up Row matrix ,matrix Specifically set as follows:

[0090] ;

[0091] Step 8: Region-based , construct regions Self-modal matrix ,area Self-modal matrix Specifically set as follows:

[0092] ;

[0093] ;

[0094] ;

[0095] ;

[0096] in, Indicates the region The projection coefficient matrix, Indicates the order is The identity matrix, Indicated by the projection function The matrix formed Indicated by the projection function The matrix formed Representation matrix No. element, Representation matrix No. element;

[0097] If the area One side is the active coil region, then the region Self-modal matrix Set as ;

[0098] Step 9: Calculate the self-modality matrix of the common boundary of each adjacent domain, and concatenate the self-modality matrices vertically according to the global order of the unknown vectors to obtain the concatenated matrix. splicing matrix Specifically set as follows:

[0099] ;

[0100] in, Represents the global coefficient matrix. This represents the vector of unknown coefficients after global concatenation.

[0101] Preferably, step S3 specifically includes the following steps:

[0102] S31: According to the Biot-Savart law, calculate the ratio of the magnetic flux density produced by a finite-length straight conductor to that produced by an infinite-length straight conductor, and correct the error of the two-dimensional subdomain model in the third-dimensional direction. The specific calculation method is set as follows:

[0103] ;

[0104] ;

[0105] ;

[0106] ;

[0107] ;

[0108] in, This represents the correction factor for a straight conductor of finite length. and This represents the geometric distance from the observation point to the center positions of the left and right conductors of the transmitting coil. and Indicates the coordinates of the midpoint of the projection and the observation point The difference in direction, in a two-dimensional plane, and This indicates the boundary position of the left conductor of the transmitting coil. and Indicates the boundary position of the conductor on the right side of the transmitting coil;

[0109] S32: Introducing rotation angle parameters The minimum spacing, maximum spacing, and coupling path length between adjacent turns are corrected. The specific correction method is set as follows:

[0110] ;

[0111] ;

[0112] ;

[0113] ;

[0114] ;

[0115] in, This indicates the initial angle between the receiving coil and the receiving coil directly below it. The function representing the correction for coordinate rotation. and This indicates the maximum and minimum distances between the receiving coil and the transmitting coil after rotation. This indicates the air gap between the turns of the receiving coil. and This represents the geometric node coordinates of the receiving coil before rotation. and This represents the corrected geometric node coordinates after rotation. The radius represents the axis of rotation. The coupling correction factor represents the influence of material and rotation on the magnetic field distribution. This represents the correction factor for a straight conductor of finite length. , , , Represents the rotated region The magnetic flux density components, respectively along direction and direction, This indicates the distance when the receiving coil and the transmitting coil are directly opposite each other. This represents the horizontal offset of the receiving coil after rotation. Represents the coordinates of the upper boundary of the transmitting coil;

[0116] S33: Calculate the mutual inductance between and after rotation. Mutual induction Specifically set as follows:

[0117] ;

[0118] in, This represents the current in the transmitting coil. Indicates the first of the receiving coils Turns, Indicates the total number of turns of the receiving coil;

[0119] Generate mutual inductance matrix Mutual inductance matrix Specifically set as follows:

[0120] ;

[0121] ;

[0122] in, This indicates the polarity of the receiving coil relative to the transmitting coil. Indicates the first The polarity of the receiving coil relative to the transmitting coil;

[0123] S34: Based on mutual inductance matrix Calculate the received induced voltage as a function of angle. Receive induced voltage Specifically set as follows:

[0124] ;

[0125] in, Represents angular frequency. This represents the transpose of the polarity matrix of the receiving coil;

[0126] Calculate the resistance of the receiving coil. resistance Specifically set as follows:

[0127] ;

[0128] in, Indicates the first The resistance value of each receiving coil;

[0129] Calculate the total inductance of the receiving coil Total inductance Specifically set as follows:

[0130] ;

[0131] in, Indicates the first The inductance of the receiving coil;

[0132] Calculate the equivalent impedance of a series link equivalent impedance Specifically set as follows:

[0133] .

[0134] Preferably, step S4 specifically includes the following steps:

[0135] S41: Apply the SP compensation structure to the load in the circuit and calculate the load voltage of the receiving circuit. On-load voltage Specifically set as follows:

[0136] ;

[0137] in, This indicates the load impedance of the receiving circuit. This indicates that a parallel compensation capacitor is connected at the receiving end. This represents the reflected impedance from the transmitting coil to the receiving port;

[0138] S42: Based on three-dimensional circuit equations, establish a circuit model, perform frequency domain steady-state simulation of the circuit model, and calculate the transmitter coil current. effective value , effective value Specifically set as follows:

[0139] ;

[0140] in, This indicates the peak current of the transmitting coil;

[0141] S43: Calculate time Induced voltage induced voltage Specifically set as follows:

[0142] ;

[0143] ;

[0144] in, Indicates about the rotation angle Total mutual inductance function, Indicates the transmitting coil's time The current function, Indicates rotational angular velocity. Represents rotational angular velocity The first derivative;

[0145] S44: By Dimensions Compare the effective values ​​of the velocity-related terms and the mutual inductance main term, and calculate the maximum dimensional value. and dimensional average Maximum value of dimensions and dimensional average Specifically set as follows:

[0146] ;

[0147] ;

[0148] in, Indicates angle sensitivity, Indicates mechanical angular velocity;

[0149] S45: Yes The average power was simulated and analyzed for shaft offset, and the analysis results were obtained. Analysis results Specifically set as follows:

[0150] ;

[0151] in, This represents the peak complex voltage across the load. This represents the peak complex current flowing through the load. Represents peak complex current phasor form;

[0152] Perform on the receiving coil Lateral displacement scan of the axis yields analysis results. Analysis results Specifically set as follows:

[0153] ;

[0154] ;

[0155] in, This represents the average power without offset. Indicates relative power transfer efficiency;

[0156] For the case of rotation, Specifically set as follows:

[0157] ;

[0158] S46: Calculate the number of receiving coils Number of receiving coils Specifically set as follows:

[0159] ;

[0160] ;

[0161] in, Indicates the center step distance. This indicates the width occupied by each coil tangentially along the circumference. Indicates the minimum gap between adjacent coils. Indicates the diameter of the rotating shaft;

[0162] Calculate the center angular position of each coil relative to the reference phase of the starting coil. The included angle included angle Specifically set as follows:

[0163] ;

[0164] ;

[0165] ;

[0166] in, This indicates the angle between adjacent receiving coils. Indicates the number of receiving coils on the shaft;

[0167] S47: Calculate the compensation of the SP compensation structure ,compensate Specifically set as follows:

[0168] ;

[0169] in, Indicates the first The inductance value of each receiving coil.

[0170] Therefore, the present invention employs the above-described chain-type multi-segment receiving wireless power transmission method suitable for rotating shafts, which has the following beneficial effects:

[0171] (1) This scheme uses multiple small receiving coils arranged in series along the circumferential axis of rotation, in conjunction with a ferrite backplate, to achieve continuous coupling coverage of the cylindrical surface, effectively solving the problem that traditional single large coils are difficult to adapt to different shaft diameters and rotational misalignment;

[0172] (2) This scheme achieves universal coverage from small shaft diameter to large shaft diameter by formulaically calculating the number and length of the receiving coil, which significantly improves the applicability and engineering adaptability of radio transmission. At the same time, by compensating the topology, it effectively suppresses coupling fluctuations during rotation and improves the continuity and stability of power transmission.

[0173] (3) This scheme establishes a two-dimensional magnetic vector potential analytical model based on Maxwell's equations, introduces a three-dimensional field correction factor and material / attitude empirical terms, realizes closed-loop solution of key parameters such as mutual inductance, voltage, and impedance, can quickly evaluate the system performance under different combinations of shaft diameter, frequency, and number of coils in the scheme stage, and supports robust design and sensitivity analysis.

[0174] (4) This scheme constructs a unified vector / matrix expression from mutual inductance matrix to open circuit voltage, load voltage and equivalent impedance, forming a closed design relationship of "shaft diameter - number of coils - compensation capacitor", which significantly reduces the design iteration cost.

[0175] The method of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0176] Figure 1 This is a flowchart of a chain-type multi-segment receiving wireless power transmission method applicable to rotating shafts according to the present invention;

[0177] Figure 2 This is an installation diagram of the chain-type receiver and transmitter of the present invention;

[0178] Figure 3 This is a structural diagram of the chain-type receiver of the present invention;

[0179] Figure 4 This is a diagram illustrating the overall architecture of the chain-type receiver and transmitter of the present invention.

[0180] Figure 5 This is a schematic diagram of the two-dimensional subdomain division and symbol for the "one-transmit, one-receive" method of the present invention;

[0181] Figure 6 This is a schematic diagram of the three types of regional boundary conditions of the present invention;

[0182] Figure 7 This is a schematic diagram of the three-dimensional rotation parameters and inter-turn distance of the present invention;

[0183] Figure 8 This is a schematic diagram of the characteristic curve of mutual inductance amplitude as a function of rotation angle according to the present invention;

[0184] Figure 9 This is the equivalent circuit of SP compensation and the mutual inductance relationship diagram of the present invention;

[0185] Figure 10This is a schematic diagram comparing the effective values ​​of the velocity-related term and the mutual inductance main term in this invention;

[0186] Figure 11 This is a schematic diagram of the average power curve under axial clearance scanning according to the present invention;

[0187] Figure 12 This is a graph showing the effect of the lateral offset on efficiency in this invention.

[0188] Figure 13 This is a small-angle rotation tolerance curve diagram of the present invention;

[0189] Figure 14 This is a schematic diagram of the design curves of the parallel compensation capacitor of the present invention under different shaft diameters and different frequencies.

[0190] The components are: 1. Chain receiver; 2. Receiver ferrite; 3. Chain receiver coil; 4. Rotating shaft; 5. Insulating sheet; 6. Transmitter; 7. Transmitter ferrite; 8. Transmitting coil; 9. Air gap. Detailed Implementation

[0191] The method of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0192] Unless otherwise defined, the methodological or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0193] The terms "comprising" or "including" as used in this invention mean that the element preceding the term encompasses the element listed after the term, and do not exclude the possibility of encompassing other elements. Terms such as "inner," "outer," "upper," and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. When the absolute position of the described object changes, the relative positional relationship may also change accordingly. In this invention, unless otherwise explicitly specified and limited, the term "attached" and similar terms should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral part; it can refer to a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication of two elements or the interaction relationship between two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0194] Example

[0195] like Figure 1As shown, the present invention provides a chain-type multi-segment receiving wireless power transfer method suitable for rotating shafts, comprising the following steps:

[0196] S1: Determine the shaft diameter, cut the chain receiver according to the shaft diameter, and install the chain receiver and transmitter on the rotating shaft;

[0197] like Figures 2-4 As shown, in step S1, the chain receiver 1 includes a receiver ferrite 2 and a chain receiver coil 3 disposed on the outer surface of the receiver ferrite 2. The receiver ferrite 2 and the rotating shaft 4 are nested together. An insulating sheet 5 (such as PI / PET / FR-4) is disposed between the receiver ferrite 2 and the rotating shaft 4 to achieve electrical isolation and wear-resistant fixation.

[0198] The transmitter 6 is located at the bottom of the rotating shaft 4. The transmitter 6 includes a transmitter ferrite 7 and a transmitter coil 8 located on the upper surface of the transmitter ferrite 7. The transmitter coil 8 is correspondingly arranged with the chain receiver coil 3. An air gap 9 is provided between the transmitter coil 8 and the chain receiver coil 3.

[0199] Each chain-type receiver coil is 3cm long, 1.5cm wide, and has 9 turns. After being connected in series, a layer with relative permeability is laid underneath it. The receiving end ferrite 2 forms a chain-type receiving end wireless charging structure. The transmitting end 6 adopts a planar rectangular coil assembly, fixed on one side of the shaft, with a length of 7cm, a width of 6cm, and 22 turns. It is excited by a 12V AC source. Similarly, the transmitting end ferrite 7 of the same thickness is laid on the bottom. The system works first in a low-frequency (such as 50kHz level) magnetic field coupling mode. The air gap 9 between the transmitting coil and the receiving coil is 1.5cm. The compensation topology is that the transmitting coil 8 is connected in series with a capacitor and the chain-type receiving end coil 3 is connected in parallel with a capacitor (SP). After the chain-type receiving end coil 3 is connected in series, parallel resonant capacitor compensation is performed to realize power convergence and rectification output.

[0200] The transmitting coil 8 uses high-frequency Litz wire to reduce the skin effect. The transmitting coil 8 is wound with Litz wire with an equivalent outer diameter of 0.8 mm and an air gap of 0.3 mm between turns. The back of the coil is bonded and fixed to the thickness using electrically insulating structural adhesive. The backplate of the transmitter ferrite 7 is 1.5mm thick. Each segment of the chain receiver coil 3 uses Litz wire with an equivalent outer diameter of about 0.5mm and an air gap of 0.1mm between turns. The chain receiver coils 3 are connected in series and pasted on the back of the ferrite sheet to form a chain receiver. Then, the number of segments and length of the chain receiver coil 3 are selected according to the shaft diameter and cut, and then placed around the shaft circumference.

[0201] S2: Establish a two-dimensional subdomain model of the chained receiver and transmitter, and solve for the coefficients of the two-dimensional subdomain model;

[0202] Step S2 specifically includes the following steps:

[0203] S21: Establish a two-dimensional subdomain model of the chain receiver and transmitter, and divide the region based on the two-dimensional subdomain diagram;

[0204] S22: As Figure 5 As shown, the two-dimensional subdomain is divided into regions. , , , , , , , , , , , , , , , and The coefficients for different regions are solved separately.

[0205] Step S22 specifically includes the following steps:

[0206] Step 1: In the case of low-frequency wireless charging, the displacement current can be ignored, that is... For the region Calculate two-dimensional Poisson using Maxwe11 Two-dimensional Poisson Specifically set as follows:

[0207] ;

[0208] ;

[0209] in, Represents the x-coordinate, Represents the coordinates in the vertical direction. Represents the permeability of free space. Indicates the region Relative permeability, Indicates the region Current density along the y-direction in a three-dimensional spatial field. Indicates the region The magnetic field strength vector;

[0210] Calculate two-dimensional Poisson general solution General solution Specifically set as follows:

[0211] ;

[0212] in, Indicates along Homogeneous solution components in the direction, Indicates along Homogeneous solution components in the direction, This represents the particular solution component generated by the current source excitation;

[0213] Two-dimensional Poisson analysis using the separation coefficient method By separating the variables, the general solution is obtained. General solution Specifically set as follows:

[0214] ;

[0215] in, Indicates the general solution equation along Solution function in coordinate direction, Indicates the general solution equation along Solution function in the coordinate direction;

[0216] Step 2: Area and region This is a passive region, area and region Current source For the passive region, the value is 0.

[0217] ;

[0218] ;

[0219] ;

[0220] in, Indicates the region Internal magnetic vector potential in The second derivative of the direction, Indicates the region Internal magnetic vector potential in The second derivative of the direction, Represents the constant of the separated variables. Representation and pattern number The corresponding eigenvalue parameters, Indicates the region Internal Spatial frequency of direction, This indicates the mode number, i.e., the spatial harmonic number. Indicates any region The upper boundary along the axial direction, Represents any region The lower boundary in the axial direction, Indicates the region The maximum mode order of the internal expansion, i.e., the maximum spatial harmonic number;

[0221] right Solving for the problem, we get:

[0222] ;

[0223] in, Indicates the solution of the separated variables in The direction is an undetermined coefficient, determined by the regional boundary conditions;

[0224] right Solving for the problem, we get:

[0225] ;

[0226] ;

[0227] ;

[0228] in, and Indicates the region The expansion coefficients of the inner m-th order mode in the z-direction. and Indicates the region Inner n-order mode in The expansion coefficient in the direction, Represents any region The upper boundary along the axial direction, Represents any region The lower boundary in the axial direction, and Indicates the region Spatial frequency within, and This indicates the mode number, i.e., the spatial harmonic number. Indicates the region Internal The maximum mode order in directional expansion, i.e., the maximum spatial harmonic number. Indicates the region Internal The maximum mode order of directional expansion;

[0229] In the modeling process of the embodiment, special solution terms Represents the volume current density within the region The magnetic vector potential generated by the excitation is zero when there is no current in the region, retaining only the contribution of the homogeneous solution. For example, for the region... and Since there is no internal excitation current, all special solutions of its magnetic vector potential are zero, and only parameters such as the homogeneous solution coefficients need to be solved. This approach not only simplifies the solution process but also ensures the physical consistency of the equations in each region.

[0230] Step 3: Area ,area ,area ,area ,area ,area and region For the air domain:

[0231] ;

[0232] ;

[0233] Step 4: For the aluminum conductor region, due to the material's high conductivity... Eddy currents are generated under the influence of an alternating magnetic field, defining skin depth. By introducing the skin effect into the aluminum conductor region, the magnetic vector potential equation for the aluminum conductor region is obtained. The specific setting of the magnetic vector potential equation for the aluminum conductor region is as follows:

[0234] ;

[0235] ;

[0236] in, Indicates the region The magnetic vector potential within. The imaginary unit is used to represent vectors. Represents angular frequency. Indicates electrical conductivity;

[0237] The magnetic vector potential equation for the aluminum conductor region was calculated, and the following was obtained:

[0238] ;

[0239] ;

[0240] in, and Indicates the corrected spatial frequency;

[0241] Step 5: Area ,area and region For the air region in contact with ferrite or a rotating shaft, under the premise of no surface current plate, apply interface conditions of continuous vector potential and continuous tangential magnetic field. For the air region in contact with ferrite or a rotating shaft:

[0242] ;

[0243] Step 6: For the region outer boundary Applying magnetic vector potential conditions Based on orthogonality, we obtain:

[0244] ;

[0245] .

[0246] S23: As Figure 6 As shown, the coefficients are solved based on the boundary conditions of different regions.

[0247] Step S23 specifically includes the following steps:

[0248] Step 1: For the region ,area ,area and region The boundary conditions are:

[0249] ;

[0250] ;

[0251] and Indicates the region upper boundary place and The normal magnetic flux density component, and This represents the magnetic field boundary function at the boundary of different regions. and Indicates the region Adjacent region index set, Indicates the permeability of adjacent regions. and This represents the magnetic flux density components of adjacent regions at the boundary. and This represents the x-coordinate of the adjacent regions at the boundary. and Represented as a boundary indicator function, when When in region r, It is 1 if it is 1, otherwise it is 0. When the region is n, It is 1 if it is true, otherwise it is 0;

[0252] Step Two: For the region ,area ,area ,area ,area ,area and region Each edge of this type of subdomain is connected to only one adjacent subdomain (not directly connected to the outer frame, nor is it a segmented interface). Therefore, the four edges of the region connect to adjacent subdomains. Apply continuous vector potential and continuous tangential magnetic field matching across the entire segment, with the following boundary conditions:

[0253] ;

[0254] ;

[0255] ;

[0256] ;

[0257] in, Indicates the region upper boundary Magnetic vector potential at the location Indicates the region lower boundary Magnetic vector potential at the location Indicates the region Right boundary Magnetic vector potential at the location Indicates the region Left boundary The magnetic vector potential at the location;

[0258] Step 3: For the region ,area ,area ,area and region These regions have at least one edge connecting to the outer boundary of the computational domain, and the boundary conditions are:

[0259] ;

[0260] ;

[0261] ;

[0262] ;

[0263] in, Indicates the region Right boundary Magnetic induction intensity in the normal direction at that location. This represents the permeability of region G2. Indicates that region G2 is at the boundary Magnetic induction intensity in the normal direction at that location. This represents the permeability of region G3. Indicates the region Left boundary Magnetic induction intensity in the normal direction at that location. Indicates that region G3 is at the boundary Magnetic induction intensity in the normal direction at the location;

[0264] Step 4: For any region and region Neighboring regions with the same magnetic vector potential The boundary conditions are:

[0265] ;

[0266] in, Represents any region and region Neighboring regions with the same magnetic vector potential The magnetic vector potential relation on the common boundary, Indicates the region The magnetic vector potential, Indicates the region The magnetic vector potential, Indicates the region homogeneous solution components, Indicates the region homogeneous solution components, Indicates the region The special solution, Indicates the region Special solution;

[0267] Step 5: Area For coil domain, region The particular solution is ,area With the region Adjacent, region For passive air domain, region The particular solution is 0, in the region For ferrite regions, region Both sides are passive regions. With the region Adjacent, region For air domain, region The particular solution is 0;

[0268] Step Six: Region-based With the region ,right The projection process is performed, and the projection principle is specifically set as follows:

[0269] ;

[0270] in, Indicates the function to be projected. Represents the projection function. Represents a function on an interval AND function The normalized integral result;

[0271] The corresponding algebraic equation is obtained, and the algebraic equation is specifically set as follows:

[0272] ;

[0273] ;

[0274] ;

[0275] ;

[0276] ;

[0277] ;

[0278] in, and and represent regions Inner expansion coefficient, and and represent regions Inner expansion coefficient, and The result of the function representing the projection operation. and This represents the weighted projection result. , , , , , These are basis functions for separating constants;

[0279] Step 7: Region-based With the region ,set up Row matrix ,matrix Specifically set as follows:

[0280] ;

[0281] Step 8: Region-based , construct regions Self-modal matrix ,area Self-modal matrix Specifically set as follows:

[0282] ;

[0283] ;

[0284] ;

[0285] ;

[0286] in, Indicates the region The projection coefficient matrix, Indicates the order is The identity matrix, Indicated by the projection function The matrix formed Indicated by the projection function The matrix formed Representation matrix No. element, Representation matrix No. element;

[0287] If the area One side is the active coil region, then the region Self-modal matrix Set as ;

[0288] Step 9: Calculate the self-modality matrix of the common boundary of each adjacent domain, and concatenate the self-modality matrices vertically according to the global order of the unknown vectors to obtain the concatenated matrix. splicing matrix Specifically set as follows:

[0289]

[0290] in, Represents the global coefficient matrix. This represents the vector of unknown coefficients after global concatenation.

[0291] S3: Based on the 3D field, the two-dimensional subdomain model is corrected, and the two-dimensional result is equivalently mapped to the three-dimensional magnetic flux density to obtain the mutual inductance M matrix of the coils of the chain receiver and transmitter.

[0292] Step S3 specifically includes the following steps:

[0293] S31: According to the Biot-Savart law, calculate the ratio of the magnetic flux density produced by a finite-length straight conductor to that produced by an infinite-length straight conductor, and correct the error of the two-dimensional subdomain model in the third-dimensional direction. The specific calculation method is set as follows:

[0294] ;

[0295] ;

[0296] ;

[0297] ;

[0298] ;

[0299] in, This represents the correction factor for a straight conductor of finite length. and This represents the geometric distance from the observation point to the center positions of the left and right conductors of the transmitting coil. and Indicates the coordinates of the midpoint of the projection and the observation point The difference in direction, in a two-dimensional plane, and This indicates the boundary position of the left conductor of the transmitting coil. and Indicates the boundary position of the conductor on the right side of the transmitting coil;

[0300] S32: As Figure 7 As shown, to describe the effect of shaft spin on the coupling relationship between the segmented coils of the transmitter and the chain receiver, a rotation angle parameter is introduced. Establish geometric mapping relationships based on the coordinate system, and assume... This is a reference phase (e.g., the initial alignment angle of the transmitter reference segment relative to the receiver).

[0301] At angle Below, the center position and inter-turn distance of the segmented coil change periodically with the angle. A correction amount is defined, where... This refers to the turn number within this segment. This refers to the turn spacing.

[0302] This item follows It exhibits a cosine-like variation and can be regarded as an "equivalent lateral misalignment" compensation amount introduced by rotation, used to correct the minimum and maximum spacing between turns and the length of the coupling path.

[0303] Introducing rotation angle parameter The minimum spacing, maximum spacing, and coupling path length between adjacent turns are corrected. The specific correction method is set as follows:

[0304] ;

[0305] ;

[0306] ;

[0307] ;

[0308] ;

[0309] in, This represents the initial angle between the other receiving coils and the receiving coil directly below. The function representing the correction for coordinate rotation. and This indicates the maximum and minimum distances between the receiving coil and the transmitting coil after rotation. This indicates the air gap between the turns of the receiving coil. and This represents the geometric node coordinates of the receiving coil before rotation. and This represents the corrected geometric node coordinates after rotation. The radius represents the axis of rotation. The coupling correction factor represents the influence of material and rotation on the magnetic field distribution. This represents the correction factor for a straight conductor of finite length. , , , Represents the rotated region The magnetic flux density components, respectively along direction and direction, This indicates the distance when the receiving coil and the transmitting coil are directly opposite each other. This indicates the horizontal offset of the receiving coil after rotation, used to correct for the coil's position after rotation. Translation in direction, Represents the coordinates of the upper boundary of the transmitting coil;

[0310] S33: A formula for calculating the mutual inductance between the transmitting coil and a receiving coil is given, dividing the cross-section surrounding the receiving coil into four rectangular planes: the top / bottom is the x-y plane (…). ), left / right are y−z planes ( ), calculate the mutual inductance between after rotation and Mutual induction Specifically set as follows:

[0311] ;

[0312] in, This represents the current in the transmitting coil. Indicates the first of the receiving coils Turns, Indicates the total number of turns of the receiving coil;

[0313] In the case of multiple receiving coils connected in series in the model, the mutual inductance matrix is ​​generated. Mutual inductance matrix Specifically set as follows:

[0314] ;

[0315] ;

[0316] in, This indicates the polarity of the receiving coil relative to the transmitting coil. Indicates the first The polarity of the receiving coil relative to the transmitting coil;

[0317] like Figure 8 As shown, in the given set (plane Tx is located below the outer side of the shaft, and Rx is arranged in segments around the axial direction), the mutual inductance amplitude M varies with the rotation angle. It exhibits a clear "primary-secondary-far side" partitioning characteristic.

[0318] Among them, Rx1 and Rx2 are the main coupling segments, when When Rx1 is directly opposite Tx, To be the global maximum, follow Rx2 increases monotonically as it enters the high-throughput region from the edge; both of them... The peaks intersect and are "handed over".

[0319] Rx3 is the next nearest neighbor. Follow Slowly rising, peaking at approximately This indicates that only a portion of the magnetic flux enters the central flux region. Rx4-Rx7 is the distal segment. Basically does not change with angle ( The fluctuation is only on the order of Nahens, indicating that segments far from Tx are almost unaffected by rotation.

[0320] The above trend originates from the change in the relative positions of the center-edge magnetic flux distribution of the planar rectangle Tx and the segments of Rx; with As the number of Rx1 increases, the strongest coupling gradually shifts from Rx1 to Rx2, thus forming the rising / falling and crossing behaviors shown in the diagram.

[0321] S34: Based on mutual inductance matrix Ignoring inter-turn coupling of the coil, calculate the received induced voltage as a function of angle. Receive induced voltage Specifically set as follows:

[0322] ;

[0323] in, Represents angular frequency. This represents the transpose of the polarity matrix of the receiving coil;

[0324] Calculate the resistance of the receiving coil. resistance Specifically set as follows:

[0325] ;

[0326] in, Indicates the first The resistance value of each receiving coil;

[0327] Calculate the total inductance of the receiving coil Total inductance Specifically set as follows:

[0328] ;

[0329] in, Indicates the first The inductance of the receiving coil;

[0330] Calculate the equivalent impedance of a series link equivalent impedance Specifically set as follows:

[0331] .

[0332] S4: Based on the mutual inductance M matrix, the model is uniformly expressed under the SP topology, and the compensation capacitor is tuned;

[0333] Step S4 specifically includes the following steps:

[0334] S41: Apply the SP compensation structure to the load in the circuit and calculate the load voltage of the receiving circuit. On-load voltage Specifically set as follows:

[0335] ;

[0336] in, This indicates the load impedance of the receiving circuit. This indicates that a parallel compensation capacitor is connected at the receiving end. This represents the reflected impedance from the transmitting coil to the receiving port;

[0337] S42: As Figure 9As shown, a circuit model is established based on three-dimensional circuit equations. Frequency domain steady-state simulation is then performed on the circuit model. A 50kHz, 12V sinusoidal excitation is applied at the transmitting end, and a resistor is used at the receiving end. As a load, calculate the current in the transmitting coil. effective value , effective value Specifically set as follows:

[0338] ;

[0339] in, This indicates the peak current of the transmitting coil;

[0340] S43: Calculate time Induced voltage The first term is the mutual inductance term (related to the excitation change), the second term is the velocity term (caused by the change in mutual inductance with angle), and the induced voltage... Specifically set as follows:

[0341] ;

[0342] ;

[0343] in, Indicates about the rotation angle Total mutual inductance function, Indicates the transmitting coil's time The current function, Indicates rotational angular velocity. Represents rotational angular velocity The first derivative;

[0344] S44: By Dimensions Compare the effective values ​​of the velocity-related terms and the mutual inductance main term, and calculate the maximum dimensional value. and dimensional average Maximum value of dimensions and dimensional average Specifically set as follows:

[0345] ;

[0346] ;

[0347] in, Indicates angle sensitivity, Indicates mechanical angular velocity;

[0348] like Figure 10 As shown in the figure It increases approximately linearly with the rotational speed, but the magnitude is extremely small: at 50kHz and 3000rpm, the worst is only 0.0468% (average 0.033%), which is negligible.

[0349] S45: Yes The average power was simulated and analyzed for shaft offset, and the analysis results were obtained. Analysis results Specifically set as follows:

[0350] ;

[0351] in, This represents the peak complex voltage across the load. This represents the peak complex current flowing through the load. Represents peak complex current phasor form;

[0352] like Figure 11 As shown, the curve is single-peaked. When the receiving coil moves closer to the transmitting coil, the coupling is enhanced and the average power rises rapidly. After moving closer to a certain position, it reaches the peak value, and then the power decreases rapidly as it moves away from the transmitting coil.

[0353] Perform on the receiving coil Lateral displacement scan of the axis yields analysis results. Analysis results Specifically set as follows:

[0354] ;

[0355] ;

[0356] in, This represents the average power without offset. Indicates relative power transfer efficiency;

[0357] like Figure 12 As shown, The efficiency is approximately 82–83%, indicating that the system has some robustness to lateral offset, but it still incurs an efficiency loss of about 17% under offsets of 1 cm.

[0358] For the case of rotation, Specifically set as follows:

[0359] ;

[0360] like Figure 13 As shown, the overall fluctuation range is only ±0.3% (peak-to-valley is about 0.56%), indicating that the system is extremely insensitive to small-angle rotation and has good angle tolerance.

[0361] S46: For wireless charging of devices with different shaft diameters, consider using different numbers of receiver coils arranged around the axis, allowing for small engineering tolerances. Calculate the number of receiver coils. Number of receiving coils Specifically set as follows:

[0362] ;

[0363] ;

[0364] in, Indicates the center step distance. This indicates the width occupied by each coil tangentially along the circumference. Indicates the minimum gap between adjacent coils. Indicates the diameter of the rotating shaft;

[0365] Calculate the center angular position of each coil relative to the reference phase of the starting coil. The included angle included angle Specifically set as follows:

[0366] ;

[0367] ;

[0368] ;

[0369] in, This indicates the angle between adjacent receiving coils. Indicates the number of receiving coils on the shaft;

[0370] S47: Calculate the compensation of the SP compensation structure ,compensate Specifically set as follows:

[0371] ;

[0372] in, Indicates the first The inductance value of each receiving coil.

[0373] like Figure 14 As shown, select the operating frequency. Then, the initial capacitance values ​​for different shaft diameters are quickly given. The larger the shaft diameter (the more chain receiving coils can be inserted around the circumference), the larger the equivalent inductance of the series link, and the smaller the required parallel capacitance. Four curves quantitatively show this. Scale relationship: Increase shaft diameter (increase) Increasing the operating frequency will significantly reduce the required parallel capacitance, and a consistent compensation design rule can be established across different shaft diameter specifications.

[0374] S5: Simulates different operating conditions to evaluate the robustness of the chain receiver and transmitter, and outputs the final voltage.

[0375] Therefore, this invention adopts the above-mentioned chain-type multi-segment receiving wireless power transmission method applicable to rotating axes. It obtains the magnetic vector potential solution and boundary matching equation that can be solved in a closed form on a two-dimensional subdomain model. Combined with the three-dimensional field correction factor, it constructs the mutual inductance analytical expression and mutual inductance matrix. Under the SP topology, it gives a unified vector and matrix expression from mutual inductance to open circuit and load voltage, equivalent impedance and compensation capacitor. Finally, it forms a consistent selection rule of "shaft diameter-number of coils-parallel capacitor" to achieve robust design against rotation or offset.

[0376] Finally, it should be noted that the above embodiments are only used to illustrate the method of the present invention and not to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the method of the present invention, and these modifications or equivalent substitutions should not cause the modified method to deviate from the spirit and scope of the method of the present invention.

Claims

1. A chain-type multi-segment receiving wireless power transmission method suitable for rotating shafts, characterized in that, Includes the following steps: S1: Determine the shaft diameter, cut the chain receiver according to the shaft diameter, and install the chain receiver and transmitter on the rotating shaft; In step S1, the chain receiver includes a receiver ferrite and a chain receiver coil disposed on the outer surface of the receiver ferrite. The receiver ferrite is nested with the rotating shaft, and an insulating sheet is disposed between the receiver ferrite and the rotating shaft. The transmitter is disposed at the bottom of the rotating shaft. The transmitter includes a transmitter ferrite and a transmitter coil disposed on the upper surface of the transmitter ferrite. The transmitter coil is disposed correspondingly to the chain receiver coil, and an air gap is disposed between the transmitter coil and the chain receiver coil. S2: Establish a two-dimensional subdomain model of the chained receiver and transmitter, and solve for the coefficients of the two-dimensional subdomain model; S3: Based on the 3D field, the two-dimensional subdomain model is corrected, and the two-dimensional result is equivalently mapped to the three-dimensional magnetic flux density to obtain the mutual inductance M matrix of the coils of the chain receiver and transmitter. S4: Based on the mutual inductance M matrix, the model is uniformly expressed under the SP topology, and the compensation capacitor is tuned; Step S4 specifically includes the following steps: S41: Apply the SP compensation structure to the load in the circuit and calculate the load voltage of the receiving circuit. On-load voltage Specifically set as follows: in, This represents the equivalent impedance of a series link. This indicates the load impedance of the receiving circuit. This indicates that a parallel compensation capacitor is connected at the receiving end. This represents the reflected impedance from the transmitting coil to the receiving port; S42: Based on three-dimensional circuit equations, establish a circuit model, perform frequency domain steady-state simulation of the circuit model, and calculate the transmitter coil current. effective value Valid value Specifically set as follows: in, This indicates the peak current of the transmitting coil; S43: Calculate time Induced voltage induced voltage Specifically set as follows: in, Indicates about the rotation angle Total mutual inductance function, Indicates the transmitting coil's time The current function, Indicates rotational angular velocity. Represents rotational angular velocity The first derivative; S44: By Dimensions Compare the effective values ​​of the velocity-related terms and the mutual inductance main term, and calculate the maximum dimensional value. and dimensional average Maximum value of dimensions and dimensional average Specifically set as follows: in, Indicates angle sensitivity, Indicates mechanical angular velocity; S45: Yes The average power was simulated and analyzed for shaft offset, and the analysis results were obtained. Analysis results Specifically set as follows: in, This represents the peak complex voltage across the load. This represents the peak complex current flowing through the load. Represents peak complex current phasor form; Perform on the receiving coil Lateral displacement scan of the axis yields analysis results. Analysis results Specifically set as follows: in, This represents the average power without offset. Indicates relative power transfer efficiency; For the case of rotation, Specifically set as follows: ； S46: Calculate the number of receiving coils Number of receiving coils Specifically set as follows: in, Indicates the center step distance. This indicates the width occupied by each coil tangentially along the circumference. Indicates the minimum gap between adjacent coils. Indicates the diameter of the rotating shaft; Calculate the center angular position of each coil relative to the reference phase of the starting coil. The included angle included angle Specifically set as follows: in, This indicates the angle between adjacent receiving coils. Indicates the number of receiving coils on the shaft; S47: Calculate the compensation of the SP compensation structure ,compensate Specifically set as follows: in, Indicates the first The inductance value of each receiving coil; S5: Simulates different operating conditions to evaluate the robustness of the chain receiver and transmitter, and outputs the final voltage.

2. The chain-type multi-segment receiving wireless power transmission method suitable for rotating shafts according to claim 1, characterized in that, Step S2 specifically includes the following steps: S21: Establish a two-dimensional subdomain model of the chain receiver and transmitter, and divide the region based on the two-dimensional subdomain diagram; S22: Divide the two-dimensional subdomain into regions , , , , , , , , , , , , , , , and The coefficients for different regions are solved separately. S23: Solve for coefficients based on the boundary conditions of different regions.

3. The chain-type multi-segment receiving wireless power transmission method suitable for rotating shafts according to claim 2, characterized in that, Step S22 specifically includes the following steps: Step 1: For the region Calculate two-dimensional Poisson using Maxwe11 Two-dimensional Poisson Specifically set as follows: in, Represents the x-coordinate, Represents the coordinates in the vertical direction. Represents the permeability of free space. Indicates the area Relative permeability, Indicates the area Current density along the y-direction in a three-dimensional spatial field. Indicates the area The magnetic field strength vector; Calculate two-dimensional Poisson general solution General solution Specifically set as follows: in, Indicates along Homogeneous solution components in the direction, Indicates along Homogeneous solution components in the direction, This represents a particular solution component generated by current source excitation; Two-dimensional Poisson analysis using the separation coefficient method By separating the variables, the general solution is obtained. General solution Specifically set as follows: in, Indicates the general solution equation along Solution function in the coordinate direction, Indicates the general solution equation along Solution function in the coordinate direction; Step 2: Area and region This is a passive region, area and region Current source For the passive region, the value is 0. in, Indicates the area Internal magnetic vector potential in The second derivative of the direction, Indicates the area Internal magnetic vector potential in The second derivative of the direction, Represents the constant of the separated variables. Representation and pattern number The corresponding eigenvalue parameters, Indicates the area Inner Spatial frequency of direction, This indicates the mode number, i.e., the spatial harmonic number. Indicates any region The upper boundary along the axial direction, Represents any region The lower boundary in the axial direction, Indicates the area The maximum mode order of the internal expansion, i.e., the maximum spatial harmonic number; right Solving for the problem, we get: in, Indicates the solution of the separated variables in The direction is an undetermined coefficient, determined by the regional boundary conditions; right Solving for the problem, we get: in, and Indicates the area The expansion coefficients of the inner m-th order mode in the z-direction. and Indicates the area Inner n-order mode in The expansion coefficient in the direction, Represents any region The upper boundary along the axial direction, Represents any region The lower boundary in the axial direction, and Indicates the area Spatial frequency within, and This indicates the mode number, i.e., the spatial harmonic number. Indicates the area Inner The maximum mode order in directional expansion, i.e., the maximum spatial harmonic number. Indicates the area Inner The maximum mode order of directional expansion; Step 3: Area ,area ,area ,area ,area ,area and region For the air domain: ； Step 4: Define skin depth By introducing the skin effect into the aluminum conductor region, the magnetic vector potential equation for the aluminum conductor region is obtained. The specific setting of the magnetic vector potential equation for the aluminum conductor region is as follows: in, Indicates the area The magnetic vector potential within. Represents the imaginary unit. Represents angular frequency. Indicates electrical conductivity; The magnetic vector potential equation for the aluminum conductor region was calculated, and the following was obtained: in, and Indicates the corrected spatial frequency; Step 5: Area ,area and region For the air region in contact with the ferrite or the rotating shaft: ； Step 6: For the region outer boundary Applying magnetic vector potential conditions Based on orthogonality, we obtain: 。 4. The chain-type multi-segment receiving wireless power transmission method suitable for rotating shafts according to claim 3, characterized in that, Step S23 specifically includes the following steps: Step 1: For the region ,area ,area and region The boundary conditions are: in, and Indicates the area upper boundary place and The normal magnetic flux density component, and This represents the magnetic field boundary function at the boundary of different regions. and Indicates the area Adjacent region index set, Indicates the permeability of adjacent regions. and This represents the magnetic flux density components of adjacent regions at the boundary. and This represents the x-coordinate of the adjacent regions at the boundary. and Represented as a boundary indicator function, when When in region r, It is 1 if it is 1, otherwise it is 0. When the region is n, It is 1 if it is true, otherwise it is 0. Step Two: For the region ,area ,area ,area ,area ,area and region On the four edges of the region, the adjacent domains Apply continuous vector potential and continuous tangential magnetic field matching across the entire segment, with the following boundary conditions: in, Indicates the area upper boundary Magnetic vector potential at the location Indicates the area lower boundary Magnetic vector potential at the location Indicates the area Right boundary Magnetic vector potential at the location Indicates the area Left boundary The magnetic vector potential at the location; Step 3: For the region ,area ,area ,area and region The boundary conditions are: in, Indicates the area Right boundary The magnetic induction intensity in the normal direction at that location. This represents the permeability of region G2. Indicates that region G2 is at the boundary The magnetic induction intensity in the normal direction at that location. This represents the permeability of region G3. Indicates the area Left boundary The magnetic induction intensity in the normal direction at that location. Indicates that region G3 is at the boundary Magnetic induction intensity in the normal direction at the location; Step 4: For any region and region Neighboring regions with the same magnetic vector potential The boundary conditions are: in, Represents any region and region Neighboring regions with the same magnetic vector potential The magnetic vector potential relation on the common boundary, Indicates the area magnetic vector potential, Indicates the area magnetic vector potential, Indicates the area homogeneous solution components, Indicates the area homogeneous solution components, Indicates the area The special solution, Indicates the area Special solution; Step 5: Area For coil domain, region The particular solution is ,area With the region Adjacent, region For passive air domain, region The particular solution is 0, in the region For ferrite regions, region Both sides are passive regions. With the region Adjacent, region For air domain, region The particular solution is 0; Step Six: Region-based With the region ,right The projection process is performed, and the projection principle is specifically set as follows: in, Indicates the function to be projected. Represents the projection function. Represents a function on an interval AND function The normalized integral result; The corresponding algebraic equation is obtained, and the algebraic equation is specifically set as follows: in, and and represent regions Inner expansion coefficient, and and represent regions Inner expansion coefficient, and The result of the function representing the projection operation. and This represents the weighted projection result. , , , , , These are basis functions for separating constants; Step 7: Region-based With the region ,set up Row matrix ,matrix Specifically set as follows: ； Step 8: Region-based , construct regions Self-modal matrix ,area Self-modal matrix Specifically set as follows: in, Indicates the area The projection coefficient matrix, Indicates the order is The identity matrix, Indicated by the projection function The matrix formed Indicated by the projection function The matrix formed Representation matrix No. element, Representation matrix No. element; If the area One side is the active coil region, then the region Self-modal matrix Set as ; Step 9: Calculate the self-modality matrix of the common boundary of each adjacent domain, and concatenate the self-modality matrices vertically according to the global order of the unknown vectors to obtain the concatenated matrix. splicing matrix Specifically set as follows: in, Represents the global coefficient matrix. This represents the vector of unknown coefficients after global concatenation.

5. A chain-type multi-segment receiving wireless power transmission method suitable for rotating shafts according to claim 4, characterized in that, Step S3 specifically includes the following steps: S31: According to the Biot-Savart law, calculate the ratio of the magnetic flux density produced by a finite-length straight conductor to that produced by an infinite-length straight conductor, and correct the error of the two-dimensional subdomain model in the third-dimensional direction. The specific calculation method is set as follows: in, This represents the correction factor for a straight conductor of finite length. and This represents the geometric distance from the observation point to the center positions of the left and right conductors of the transmitting coil. and Indicates the coordinates of the midpoint of the projection and the observation point The difference in direction, in a two-dimensional plane, and This indicates the boundary position of the left conductor of the transmitting coil. and Indicates the boundary position of the conductor on the right side of the transmitting coil; S32: Introducing rotation angle parameters The minimum spacing, maximum spacing, and coupling path length between adjacent turns are corrected. The specific correction method is set as follows: in, This indicates the initial angle between the receiving coil and the receiving coil directly below it. The function representing the correction for coordinate rotation. and This indicates the maximum and minimum distances between the receiving coil and the transmitting coil after rotation. This indicates the air gap between the turns of the receiving coil. and This represents the geometric node coordinates of the receiving coil before rotation. and This represents the corrected geometric node coordinates after rotation. The radius represents the axis of rotation. The coupling correction factor represents the influence of material and rotation on the magnetic field distribution. This represents the correction factor for a straight conductor of finite length. , , , Represents the rotated region The magnetic flux density components, respectively along direction and direction, This indicates the distance when the receiving coil and the transmitting coil are directly opposite each other. This represents the horizontal offset of the receiving coil after rotation. Represents the coordinates of the upper boundary of the transmitting coil; S33: Calculate the mutual inductance between and after rotation. Mutual induction Specifically set as follows: in, This represents the current in the transmitting coil. Indicates the first of the receiving coils Turns, Indicates the total number of turns of the receiving coil; Generate mutual inductance matrix Mutual inductance matrix Specifically set as follows: in, This indicates the polarity of the receiving coil relative to the transmitting coil. Indicates the first The polarity of the receiving coil relative to the transmitting coil; S34: Based on mutual inductance matrix Calculate the received induced voltage as a function of angle. Receive induced voltage Specifically set as follows: in, Represents angular frequency. This represents the transpose of the receiving coil polarity matrix; Calculate the resistance of the receiving coil. resistance value Specifically set as follows: in, Indicates the first The resistance value of each receiving coil; Calculate the total inductance of the receiving coil Total inductance Specifically set as follows: in, Indicates the first The inductance of the receiving coil; Calculate the equivalent impedance of a series link equivalent impedance Specifically set as follows: 。

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