Full-space magnetic coupling wireless local energy transmission system and its magnetic energy regulation method

Abstract

The present invention relates to the technical field of magnetic-coupled wireless power transmission, and specifically discloses a full-space magnetic-coupled wireless local power transmission system and a magnetic energy regulation method thereof. The power transmission system includes N ≥ 3 three-dimensional orthogonal solid coils; each three-dimensional orthogonal solid coil includes an X-plane orthogonal coil, a Y-plane orthogonal coil, and a Z-plane orthogonal coil that are respectively distributed on the X, Y, and Z coordinate planes and whose geometric centers coincide with the origin of coordinates; any combination of an X-plane orthogonal coil, a Y-plane orthogonal coil, and a Z-plane orthogonal coil forms a transmitting mechanism for full-space electromagnetic transmission. The magnetic energy regulation method selects the optimal transmitting mechanism according to the position of the receiving coil, the magnitude and direction of the desired magnetic field. After determining the optimal transmitting mechanism, the amplitudes of the three excitation currents are set according to the solutions of the non-linear programming equation, and the phases of the three excitation currents are set to be in the same phase, which can dynamically regulate the spatial distribution of magnetic energy with the position and orientation of the terminal within the effective power transmission range, eliminate the influence brought by the dead zone space, achieve omnidirectional and full-angle power transmission, and minimize magnetic leakage.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic coupling wireless power transfer (MC-WPT), and particularly to a full-space magnetic coupling wireless local power transfer system and a magnetic energy regulation method thereof. Background Art

[0002] Magnetic coupling wireless power transfer (MC-WPT) technology realizes the non-electrical connection transmission of electric energy from the power supply end to the electrical equipment end based on the magnetic field coupling principle, and has advantages such as safety, reliability, flexibility, and convenience. At present, it has been successfully applied in fields such as consumer electronics, household appliances, and electric vehicles, and has become a research hotspot in the current field of electrical engineering and automation. With the expansion of application fields and the deepening of industrialization, the spatial flexibility and efficiency of power transfer have become one of the important common requirements of this technology.

[0003] The improvement of the spatial ability of wireless power transfer has received extensive attention from domestic and foreign research scholars. At present, the improvement of the spatial ability of MC-WPT systems can be mainly divided into two categories: the magnetic coupling mechanism design of single-excitation systems and multi-excitation modes.

[0004] The improvement of the spatial ability of single-excitation systems mainly focuses on the magnetic coupling mechanism design method. The existing methods mainly include: increasing the magnetic core material, designing a 3D magnetic coupling mechanism, etc. Increasing the magnetic core material can effectively increase the longitudinal power transfer distance of magnetic coupling wireless power transfer, but the improvement of the lateral power transfer range and the degree of freedom is limited. At the same time, the magnetic core material will bring additional losses and affect the energy efficiency of the system. Designing a 3D magnetic coupling mechanism can make the magnetic field distribution exist in multiple spatial dimensions, and can effectively enhance the degree of freedom of wireless power transfer. However, the 3D magnetic coupling mechanism is usually a series structure. Once the excitation coil works, the magnetic field distributions in multiple dimensions exist simultaneously, with large magnetic leakage, large losses, and large electromagnetic interference. Due to the difficulty of simultaneously considering the transmission distance, transmission range, degree of freedom, and problems such as large losses and serious magnetic leakage in the magnetic coupling mechanism design of single-excitation systems, multi-excitation modes have received great attention in recent years.

[0005] The improvement of the system's spatial ability in the multi-excitation mode is mainly achieved by constructing a multi-coil architecture, such as a planar coil array, a three-dimensional orthogonal coil architecture, etc. By selectively exciting different coils, the spatial ability of the system can be improved. The multi-coil architecture system can make the spatial magnetic field distribute more evenly, thus effectively increasing the magnetic energy transmission range. And by selecting different combinations of excitation coil arrays at the terminal position, on the basis of improving the system's spatial ability, the system loss can also be reduced, the magnetic leakage can be reduced, and the transmission energy efficiency can be guaranteed. However, at present, most of the multi-coil architectures are centralized energy transmission architectures. Once the structure is determined, the energy transmission space is determined, so the effective energy transmission range is relatively limited. At the same time, most of the current multi-coil excitation systems are single regulation, that is, the single variable of multiple excitation sources is regulated. The single variable includes the combination method, only the amplitude or only the phase, and it is difficult to realize the dynamic regulation of the spatial magnetic field.

[0006] As is well known, for an MC-WPT system, a sufficient condition for realizing efficient energy transmission of the system is that a certain number of magnetic force lines pass through the receiving coil. However, due to the characteristic that magnetic force lines never intersect, there must be directions in three-dimensional space where no magnetic force lines pass through, and effective electric energy transmission cannot be realized in these directions. Therefore, these directions can be defined as invalid energy transmission spaces. The invalid energy transmission space is determined by the characteristics of magnetic force lines and cannot be eliminated in essence. Dynamically regulating the magnetic field distribution of the system with the orientation of the receiving coil is an effective way to solve the problem of invalid energy transmission directions and realize effective energy transmission in the whole space. At the same time, dynamically regulating the magnetic field is also an important means to effectively reduce magnetic leakage and achieve efficient and accurate energy transmission. Summary of the Invention

[0007] The present invention provides a full-space magnetically coupled wireless local energy transmission system and its magnetic energy regulation method, and the technical problem to be solved is that: the existing multi-excitation system has a fixed structure and single regulation of multiple excitation sources, there are invalid energy transmission directions, and effective energy transmission in the whole space cannot be realized, and the system has large losses and serious magnetic leakage.

[0008] To solve the above technical problems, the present invention provides a full-space magnetically coupled wireless local energy transmission system, including N≥3 three-dimensional orthogonal solid coils;

[0009] Taking the geometric center of each three-dimensional orthogonal solid coil as the coordinate origin of its respective three-dimensional Cartesian coordinate system, each three-dimensional orthogonal solid coil includes an X-plane orthogonal coil, a Y-plane orthogonal coil, and a Z-plane orthogonal coil that are respectively distributed on the X, Y, and Z coordinate planes and whose geometric centers coincide with the coordinate origin;

[0010] During wireless power transmission, any X-plane orthogonal coil, any Y-plane orthogonal coil, and any Z-plane orthogonal coil are combined into a transmitting mechanism to perform full-space electromagnetic emission.

[0011] Preferably, the N X-plane orthogonal coils, the N Y-plane orthogonal coils, and the N Z-plane orthogonal coils all adopt single emission coils with the same structure.

[0012] Preferably, the frequencies and phases of the three orthogonal coils in the emission mechanism are the same.

[0013] Preferably, the single emission coil adopts a planar coil of any shape.

[0014] The present invention also provides a magnetic energy regulation method for the above-mentioned full-space magnetic coupling wireless local energy transfer system, including the steps of:

[0015] S1. Determine the structures and positions of the N three-dimensional orthogonal solid coils and the structure and position of the receiving coil according to actual requirements;

[0016] S2. Determine the expected magnetic field magnitude and direction of the receiving coil according to actual requirements;

[0017] S3. Take each three-dimensional orthogonal solid coil as a node, and combine the single emission coils on any three X, Y, and Z planes of any node to form an emission mechanism. Assemble all the emission mechanisms to form an emission mechanism set;

[0018] S4. According to the expected magnetic field direction of the receiving coil, based on the principle of minimum leakage magnetic field, calculate the current amplitude ratios of the three orthogonal coils of each emission mechanism in the emission mechanism set;

[0019] S5. Based on the expected magnetic field magnitude of the receiving coil, determine the current amplitudes of the three orthogonal coils of each emission mechanism in the emission mechanism set;

[0020] S6. Taking the minimum loss as the goal, establish a non-linear programming model for solution to obtain the optimal node combination and the current amplitudes of the three orthogonal coils in the optimal emission mechanism corresponding to the optimal node combination;

[0021] S7. Excite the three orthogonal coils in the optimal emission mechanism with the excitation currents having the current amplitudes calculated in step S6, the same frequency, and the same phase.

[0022] Further, in step S3, the emission mechanism set Q is expressed as:

[0023] Q = {x|x = [x1, x2, x3], x1, x2, x3 ∈ (1, 2,..., N)}

[0024] Wherein, x = [x1, x2, x3] represents an emission mechanism formed by combining the X-plane orthogonal coil of the x1-th node, the Y-plane orthogonal coil of the x2-th node, and the Z-plane orthogonal coil of the x3-th node. N is the number of nodes. Therefore, there are a total of emission mechanisms in the emission mechanism set Q.

[0025] Further, in step S4, according to the expected magnetic field direction of the receiving coil and based on the principle of minimum magnetic leakage, the matrix equation for calculating the current amplitude ratio of the three orthogonal coils in any transmitting mechanism is expressed as follows:

[0026]

[0027] where, T ui is the current coefficient of the magnetic field component of orthogonal coil i in the u direction, represents the plane normal vector of the receiving coil, a, b, and c are the coefficients of the unit vectors in the x, y, and z directions respectively, I i represents the current amplitude of orthogonal coil i, is the proportionality coefficient, H u is the magnetic field component of the total combined magnetic field of the three orthogonal coils in the u direction, i = 1, 2, 3, u = x, y, z. Here, the three-dimensional Cartesian coordinate system established is based on the three-dimensional Cartesian coordinate system of any three-dimensional orthogonal solid coil.

[0028] Further, the current amplitude ratio of the three orthogonal coils in any transmitting mechanism is expressed as:

[0029]

[0030] Further, in step S5, the current amplitudes of the three orthogonal coils in any transmitting mechanism are expressed as:

[0031] (I1, I2, I3) = h(H 期望 , (I1 / I2 / I3))

[0032] where, H 期望 represents the expected magnetic field magnitude of the receiving coil, h(H 期望 , (I1 / I2 / I3)) represents the function between H 期望 and I1 / I2 / I3.

[0033] Further, in step S6, the non-linear programming model is described as follows:

[0034]

[0035] where, represents the objective function, R represents the internal resistance of orthogonal coil i, r i represents the distance between orthogonal coil i in any transmitting mechanism and the receiving coil, i = 1, 2, 3, r max is the maximum effective energy transfer distance, I coilmax is the maximum current-carrying capacity of the orthogonal coil.

[0036] A full - space magnetic - coupling wireless local energy transfer system and its magnetic - energy regulation method provided by the present invention have prominent advantages as follows:

[0037] 1. A full - space magnetic - coupling wireless local energy transfer system is provided, which includes N≥3 three - dimensional orthogonal solid coils. The transmitting mechanism can be arbitrarily combined according to specific application requirements, and the selected combined transmitting mechanism is used for full - space electromagnetic emission. This mechanism can operate in two working modes: centralized three - dimensional orthogonal energy transfer (selecting one three - dimensional orthogonal solid coil as the energy - transmitting mechanism) and distributed three - dimensional orthogonal energy transfer (selecting corresponding coils from 2 or 3 three - dimensional orthogonal solid coils to form the transmitting mechanism). It is the structural basis for realizing dynamic regulation of the magnetic - energy spatial distribution with the position and orientation of the terminal within the effective energy - transfer range, eliminating the influence brought by the dead - zone space, and achieving omnidirectional and all - angle energy transfer.

[0038] 2. Based on the full - space magnetic - coupling wireless local energy transfer system as the structural basis, a magnetic - energy regulation method is provided. According to the position of the receiving coil, the desired magnetic - field magnitude and direction, the optimal transmitting mechanism is selected, and the current amplitude of the transmitting mechanism is determined and ensured to be in the same phase. It can realize dynamic regulation of the magnetic - energy spatial distribution with the position and orientation of the terminal within the effective energy - transfer range, eliminate the influence brought by the dead - zone space, and achieve omnidirectional and all - angle energy transfer; a multi - excitation collaborative control criterion is established, which can not only control the magnetic - field direction at a certain position, but also minimize the leakage magnetic field, suppress eddy - current loss, thereby effectively reducing the loss of the excitation source and improving the energy - transfer efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is the architecture diagram of the full - space magnetic - coupling wireless local energy transfer system provided by the embodiment of the present invention;

[0040] Figure 2 is the schematic diagram of the centralized three - dimensional orthogonal energy - transfer mode provided by the embodiment of the present invention;

[0041] Figure 3 is the schematic diagram of the distributed three - dimensional orthogonal energy - transfer mode provided by the embodiment of the present invention;

[0042] Figure 4 is the schematic diagram of the synthesis of any vector r in the magnetic - energy transmission space provided by the embodiment of the present invention;

[0043] Figure 5 is the schematic diagram of the analysis of the synthesized magnetic - field vector of the receiving coil provided by the embodiment of the present invention;

[0044] Figure 6 is the schematic diagram of the position of the three - orthogonal coils and the center point P provided by the embodiment of the present invention;

[0045] Figure 7 is provided by the embodiment of the present invention in Figure 6Schematic diagram of establishing an auxiliary coordinate system;

[0046] Figure 8 Schematic diagram of the synthetic magnetic field components of the three orthogonal coils provided by an embodiment of the present invention;

[0047] Figure 9 Schematic diagram of the COMSOL spatial structure provided by an embodiment of the present invention;

[0048] Figure 10 Graph of the change in the angle between the synthetic magnetic field direction at the center of the receiving coil and the normal vector of the receiving coil plane obtained after the receiving coil deflects along the X-axis provided by an embodiment of the present invention;

[0049] Figure 11 Graph of the change in the angle between the synthetic magnetic field direction at the center of the receiving coil and the normal vector of the receiving coil plane obtained after the receiving coil deflects along the Y-axis provided by an embodiment of the present invention;

[0050] Figure 12 Graph of the change in the angle between the synthetic magnetic field direction at the center of the receiving coil and the normal vector of the receiving coil plane obtained after the receiving coil deflects along the Z-axis provided by an embodiment of the present invention;

[0051] Figure 13 Schematic diagram of the spatial magnetic field lines under different current operating modes provided by an embodiment of the present invention. Detailed implementation manners

[0052] The following specifically clarifies the implementation manners of the present invention in conjunction with the accompanying drawings. The given embodiments are only for illustrative purposes and should not be construed as limitations on the present invention. The accompanying drawings are only for reference and illustration and do not constitute a limitation on the protection scope of the present invention's patent, because many changes can be made to the present invention without departing from its spirit and scope.

[0053] In order to dynamically adjust the magnetic field distribution of the system along with the orientation of the receiving coil and effectively reduce magnetic leakage, an embodiment of the present invention first provides a full-space magnetic coupling wireless local energy transfer system (or local energy transfer network), including N≥3 three-dimensional orthogonal solid coils; taking the geometric center of each three-dimensional orthogonal solid coil as the coordinate origin of its respective three-dimensional Cartesian coordinate system, each three-dimensional orthogonal solid coil includes an X-plane orthogonal coil, a Y-plane orthogonal coil, and a Z-plane orthogonal coil that are respectively distributed on the X, Y, and Z coordinate planes and whose geometric centers coincide with the coordinate origin; during wireless power transmission, any X-plane orthogonal coil, any Y-plane orthogonal coil, and any Z-plane orthogonal coil are combined into a transmitting mechanism for full-space electromagnetic transmission.

[0054] Figure 1The figure shows a schematic diagram of the transmitting mechanism when N = 4. Each of the 4 three-dimensional orthogonal solid coils serves as a node. It can be seen that the 4 X-plane orthogonal coils, 4 Y-plane orthogonal coils, and 4 Z-plane orthogonal coils all use single transmitting coils with the same structure, and the single transmitting coil uses a circular coil. In this patent, the circular coil is taken as an example. Three-orthogonal coils of any other shape can also achieve magnetic field tracking, such as regular polygon coils.

[0055] In Figure 1 the multi-node wireless power transfer network shown, according to different combination methods of the transmitting mechanism, it can be divided into a centralized three-dimensional orthogonal power transfer mode and a distributed three-dimensional orthogonal power transfer mode. The centralized three-dimensional orthogonal power transfer mode means using the three orthogonal transmitting coils (X-plane orthogonal coil, Y-plane orthogonal coil, and Z-plane orthogonal coil) of the same node as the transmitting mechanism to control the spatial magnetic field vector. The specific structure diagram is as Figure 2 shown. The distributed three-dimensional orthogonal power transfer mode means that the three orthogonal excitation coils come from different nodes, which can come from two nodes or three nodes. The structure schematic diagram is as Figure 4 shown. In Figure 2 and Figure 3 , the orthogonal dense dashed lines represent the effective power transfer range, the solid lines represent the excitation coils, and the thick dashed lines represent the unexcited coils.

[0056] Both power transfer modes can control the magnetic field direction at any point in space. However, due to the attenuation of the magnetic field, a single node can only transfer energy within a limited distance, and this range is called the effective power transfer range. In different spatial regions, the amplitudes of the currents of each coil required to generate the same magnetic field intensity vector are different for different power transfer modes, so the coil losses and system efficiencies are also different. Therefore, the corresponding power transfer mode can be preferentially selected according to the spatial region position. The magnetic energy regulation method of this transmitting mechanism is based on the following principles:

[0057] 1) For a single transmitting coil at a given position, the direction of the magnetic field vector generated at any arbitrary point in space is determined and unique, and the magnitude of the magnetic field vector is determined by the amplitude and phase angle of the excitation current;

[0058] 2) For three single transmitting coils that are geometrically orthogonal to each other, the directions of the magnetic field vectors generated by the three coils at any arbitrary point in space must be different from each other;

[0059] 3) Three magnetic field vectors with different directions can be combined into a magnetic field vector in any direction by controlling their amplitude ratios and phase angles.

[0060] The mathematical expression for vector synthesis is Equation (1), and its spatial schematic diagram is as Figure 4 shown, where are three vectors with different directions. By controlling the amplitudes of the three vectors, any vector in space can be synthesized

[0061]

[0062] Analyze the resultant magnetic field vector at the position of the receiving coil. The schematic diagram is as shown in Figure 5 .

[0063] Figure 5 In i , \(H\) i is the magnetic field vector generated by coil \(i\), i.e., Coil 合成 , where \(i = 1, 2, 3\) are the selected coil labels, and \(H\) Figure 5 is the magnetic field vector synthesized by the three orthogonal coils; \(n\) is the normal vector of the receiving coil plane.

[0064]

[0065] From Figure 3 and Equation (2), it can be known that when the receiving coil is at a certain position in the local energy transfer space and the size of the receiving coil is much smaller than that of the transmitting coil, it can be approximately regarded as a particle in the local energy transfer network. One orthogonal coil of nodes 1, 2, and 3 is respectively selected to form a transmitting mechanism. Through the multi-excitation cooperative control criterion, the resultant magnetic field at the position of the receiving coil is directed towards the direction of the normal vector of the coil plane, and there is no redundant leakage magnetic field, realizing magnetic energy regulation.

[0066] Taking any three orthogonal coils of the local energy transfer system as an example, the multi-excitation cooperative control criterion for the three orthogonal coils to achieve magnetic field control is given. Three orthogonal coils and the receiving center point \(P\) are given. Taking the geometric center of coil 1 as the origin, a coordinate system \(O1\) is established. The overall schematic diagram is as shown in Figure 6 . The coordinates of the center point \(P\) are \((x_0, y_0, z_0)\), and the coordinates of coil \(i\) are \((X\) i , \(Y\) i , \(Z\) i ), where \(i = 1, 2, 3\).

[0067] Applying the Biot-Savart law to coil 1, the spatial magnetic field excited by the exciting coil 1 at the center point \(P\) can be obtained as follows:

[0068]

[0069] Among them, is the exciting current of coil 1, \(r_1\) is the distance from the center point \(P\) to the current element on coil 1, and is the unit vector from the current element on coil 1 to the center point \(P\).

[0070] For the coils 2 and 3 to establish their own coordinate systems, only translation and rotation are needed, and the coordinates of the center point P in the coordinate systems of O2 and O3 can be obtained as shown in Equation (4). The auxiliary coordinate systems established by the coils 2 and 3 are as Figure 7 shown.

[0071]

[0072] Among them, (x i , y i , z i ) are the coordinates of the center point P in the coordinate system of the coil i (i = 1, 2, 3), R i is the rotation matrix from coil 1 to coil i (i = 2, 3), and θ1 and θ2 are the clockwise rotation angles from coil 1 to coils 2 and 3 respectively.

[0073] Since the effective transmission range of the MC-WPT system belongs to near-field propagation, within this range, the product of the electromagnetic wave number and the propagation distance is much less than 1. Combining the above analysis and substituting Equation (4) into Equation (3) for simplification, the components of the magnetic field in the Cartesian coordinate system are solved as:

[0074]

[0075] Among them, a r is the coil radius, are the unit vectors of the base directions of the center point P in the coordinate system of the coil i respectively, is the distance between the center point P and the center of the coil i, is the magnetic field vector of the coil i in its own coordinate system.

[0076] Applying the inverse rotation of the coordinate system and combining Equation (4), the expression of the spatial magnetic field excited by the coil i at the center point P in the O1 coordinate system is summarized as:

[0077]

[0078] is the representation of the magnetic field vector of the coil i in the O1 coordinate system.

[0079] Combining the superposition theorem, the x, y, and z components of the total synthesized magnetic field of the three orthogonal coils can be expressed as:

[0080]

[0081]

[0082] Among them, H x is the X component of the synthesized magnetic field, H y is the Y component of the synthesized magnetic field, H z is the Z component of the synthesized magnetic field, Hui1 is the magnetic field vector of coil i in the u direction in the O1 coordinate system, where u = x, y, z.

[0083] Plot the components of the combined magnetic field in Equation (8) in Figure 8 where H 合成 is the combined magnetic field vector under the combined action of the three coils.

[0084] Combining the plane normal vector in Figure 5 with Equation (1), the plane normal vector n of the receiving coil can be transformed into the base direction vector:

[0085]

[0086] where a, b, and c are the coefficients of the unit vectors respectively.

[0087] When Figure 8 the component ratio of the base direction of the magnetic field at the center point P of the receiving coil is equal to the component ratio of the base direction of the normal unit vector, the two vectors are parallel. Substituting Equation (8) and Equation (9) into the right equality of Equation (2) gives:

[0088]

[0089] where k is the proportionality coefficient.

[0090] Substitute Equation (10) into the left equality of Equation (2) and simplify to get:

[0091]

[0092] where T i is the geometric parameter coefficient in the magnetic field excitation formula of the orthogonal coil i, is the excitation current of the orthogonal coil i, r i is the distance from the center point P to the current element on the orthogonal coil i, is the unit vector from the current element on the orthogonal coil i to the center point P.

[0093] Express Equation (11) in the frequency domain to get:

[0094]

[0095] where i i , ω i , are the excitation current The amplitude, angular frequency and phase of the three excitation coils are shown in Figure 12. A qualitative analysis of formula (12) shows that when the three excitation coils have the same frequency and phase, the direction of the synthetic magnetic field is completely determined by the amplitude ratio of the three excitation coils and will not change over time. Based on this, in specific applications, the current of each coil is set to the same frequency and phase to ensure that H 合成 The vector direction does not change with time. The direction of the synthetic magnetic field can be controlled by adjusting the amplitude ratio. Under the condition of satisfying the amplitude ratio, the size of the synthetic magnetic field can be controlled by adjusting the amplitude, thus realizing dynamic control of the magnetic field.

[0096] When the desired magnetic field direction at the center point is given, on the basis of the current phase being controlled to be in phase, the matrix equation can be obtained by combining equation (7) and equation (10) and transforming them as follows:

[0097]

[0098] Among them, T ui is the current coefficient of the magnetic field component of the orthogonal coil i in the u direction, u = x, y, z.

[0099] By solving the matrix equation (13), the solution of the current amplitude ratio of the three orthogonal coils in a transmitting mechanism can be obtained as:

[0100]

[0101] When the expected magnetic field size at the center point is given, combining equations (11) and (14), the solution function for the current amplitude of the three orthogonal coils can be defined as follows:

[0102] (I1,I2,I3)=h(H 期望 ,(I1 / I2 / I3)) (15)

[0103] Among them, H 期望 represents the expected magnetic field size of the receiving coil, h(H 期望 , (I1 / I2 / I3)) represents H 期望 Function between I1 / I2 / I3.

[0104] It can be seen that when the geometric center of the three orthogonal coils and the desired magnetic field direction are given, the current amplitude is only related to the current amplitude ratio and the desired magnetic field size. Therefore, by solving equation (15), the specific current amplitude of the selected three orthogonal coils can be obtained. By passing the above-mentioned excitation current through the three orthogonal coils, the coils can generate a magnetic field vector of the desired size and perpendicular to the coil plane at the center point.

[0105] Combined with the above theoretical analysis, any three orthogonal coils, that is, any transmitting mechanism, can achieve magnetic energy regulation, that is, the above combinations can all generate the desired magnetic field magnitude and direction at the center point by adjusting the current amplitude and phase of the three orthogonal coils. Based on this, an embodiment of the present invention also provides a magnetic energy regulation method for a full-space magnetic coupling wireless local energy transmission system, specifically including the following steps:

[0106] S1. Determine the structures and positions of N three-dimensional orthogonal solid coils and the structure and position of the receiving coil according to actual requirements;

[0107] S2. Determine the desired magnetic field magnitude and direction of the receiving coil according to actual requirements;

[0108] S3. Take each three-dimensional orthogonal solid coil as a node, and combine the single transmitting coils on any three X, Y, and Z planes of any node into a transmitting mechanism, and form a set of transmitting mechanisms by aggregating all the transmitting mechanisms;

[0109] S4. Calculate the current amplitude ratios of the three orthogonal coils of each transmitting mechanism in the set of transmitting mechanisms based on the principle of minimum leakage magnetic flux according to the desired magnetic field direction of the receiving coil;

[0110] S5. Determine the current amplitudes of the three orthogonal coils of each transmitting mechanism in the set of transmitting mechanisms based on the desired magnetic field magnitude of the receiving coil;

[0111] S6. Establish a non-linear programming model for solution with the goal of minimum loss to obtain the optimal node combination and the current amplitudes of the three orthogonal coils in the optimal transmitting mechanism corresponding to this optimal node combination;

[0112] S7. Excite the three orthogonal coils in the optimal transmitting mechanism with the exciting currents having the current amplitudes calculated in step S6, the same frequency, and the same phase.

[0113] In these steps, in step S4, according to the above theoretical analysis, the current amplitude ratios of the three orthogonal coils in any transmitting mechanism can be obtained, and in step S5, the current amplitudes of the three orthogonal coils in any transmitting mechanism can be further obtained based on the desired magnetic field magnitude of the receiving coil. Another key lies in how to determine the optimal transmitting mechanism, that is, step S6.

[0114] According to Figure 2 、 Figure 3 it can be known that when the receiving coil is at different positions, there are different combinations of three orthogonal coils located in the same or in two or three nodes respectively. Since the origin coordinates of the three orthogonal coils in different combinations are different, the magnitudes of the exciting currents on the three orthogonal coils in different combinations are also different. At the same time, since different currents will generate different magnetic coupling mechanism losses P loss, in the use of an actual system, the lower the loss, the better. Therefore, a non-linear programming model for selecting three orthogonal coils needs to be established to determine the optimal combination of nodes for the three different orthogonal coils.

[0115] Since any three orthogonal coils can achieve the function of magnetic energy regulation in three-dimensional space, that is, there are multiple optional combinations of three orthogonal coils, the relationship between the maximum number of optional combinations n and the total number of nodes N is as shown in the formula.

[0116]

[0117] For the local energy transfer network architecture, different central coordinates of the nodes where the coils are located will affect the magnitude of the excitation current, thus resulting in different dielectric losses. Therefore, the system optimization goal is the loss of the magnetic coupling mechanism, and this goal is mainly related to the node coordinates. The objective function f(x) is defined as:

[0118]

[0119] Among them, Q represents the set of transmitting mechanisms, x = [x1, x2, x3] represents the transmitting mechanism composed of the orthogonal coil on the X plane at the x1-th node, the orthogonal coil on the Y plane at the x2-th node, and the orthogonal coil on the Z plane at the x3-th node. N is the number of nodes. Therefore, there are a total of transmitting mechanisms in the transmitting mechanism set Q; I i represents the excitation current of the orthogonal coil i in the transmitting mechanism; R represents the internal resistance of the orthogonal coil i.

[0120] When the value of f(x) is smaller, it indicates that the dielectric loss of the system is lower, and the energy efficiency of the system under this set will be better than that of other sets. Therefore, the established non-linear programming goal is:

[0121]

[0122] In practical applications, the geometric structure of the nodes is determined, that is, there is a fixed effective energy transfer range. When the coil position exceeds the effective energy transfer range, the system cannot achieve power transmission. Therefore, when the receiving coil is within the effective energy transfer range of the node, the corresponding node can be included in the set considered by the algorithm for the next optimization of node combination. For the effective energy transfer range of the nodes in the local energy transfer network architecture, the distance between the receiving coil and the three orthogonal coils should satisfy:

[0123]

[0124] Among them, r max is the maximum effective energy transfer distance.

[0125] The stability of the device needs to consider the current-carrying capacity of the coil winding. When the type of the winding is determined, its current-carrying capacity is also determined. To avoid the coil being burned out, the excitation current flowing through the coil also needs to be limited within a certain reasonable range. Based on the above analysis, the magnitude of the excitation current in the three orthogonal coils should satisfy:

[0126] I i ≤I coilmax (20)

[0127] where, I coilmax is the maximum current-carrying capacity of the coil.

[0128] Based on the above analysis, the selection criterion for the three orthogonal coil nodes in the local energy transfer network architecture is a single-objective, multi-constraint non-linear optimization problem. The finally established non-linear programming model is:

[0129]

[0130] By solving the non-linear programming model of Equation (21), the node combination of the optimal three orthogonal coils in the local energy transfer network architecture can be obtained. While realizing magnetic energy regulation, the dielectric loss of the system can be minimized, and the effective energy transfer range of the system can also be increased through different combinations of nodes.

[0131] In summary, a full-space magnetic coupling wireless local energy transfer system and its magnetic energy regulation method provided by the embodiments of the present invention have the following prominent advantages:

[0132] 1. A full-space magnetic coupling wireless local energy transfer system is provided. According to specific application requirements, the transmitting mechanisms can be arbitrarily combined, and the combined transmitting mechanisms are selected for full-space electromagnetic emission. This mechanism can work in two operating modes: centralized three-dimensional orthogonal energy transfer (selecting a three-dimensional orthogonal solid coil as the transmitting mechanism for energy transfer) and distributed three-dimensional orthogonal energy transfer (selecting the corresponding coils from 2 or 3 three-dimensional orthogonal solid coils to form the transmitting mechanism). It is the structural basis for realizing the dynamic regulation of the magnetic energy spatial distribution with the change of the terminal position and orientation within the effective energy transfer range, eliminating the influence brought by the dead zone space, and realizing omnidirectional and all-angle energy transfer;

[0133] 2. Based on the full-space magnetic coupling wireless local energy transfer system as the structural basis, a magnetic energy regulation method is provided. According to the position of the receiving coil and the desired magnetic field magnitude, the optimal transmitting mechanism is selected, and the current amplitude and phase of the transmitting mechanism are determined. It can realize the dynamic regulation of the magnetic energy spatial distribution with the change of the terminal position and orientation within the effective energy transfer range, eliminate the influence brought by the dead zone space, and realize omnidirectional and all-angle energy transfer; A multi-excitation collaborative control criterion is established, which can not only control the magnetic field direction at a certain position, but also minimize the leakage magnetic field, suppress the eddy current loss, thereby effectively reducing the loss of the excitation source and improving the energy transfer efficiency.

[0134] Next, simulation verification is carried out.

[0135] For the method of multi-excitation collaborative regulation of magnetic field vectors proposed above, in this example, MATLAB numerical simulation is used to verify the direction of the synthetic magnetic field at the center of the coil under different deflection degrees, and at the same time, COMSOL finite element simulation software is used to verify the direction of the synthetic magnetic field under different current working modes. The simulation parameters are shown in Tables 1 and 2, and the spatial structure of the three transmitting coils and the receiving coil is as Figure 9 shown.

[0136] Table 1 MATLAB Simulation Parameter Settings

[0137] parameter numerical value <![CDATA[Radius a1 / m of Coil 1]]> 0.206 <![CDATA[Radius a2 / m of coil 2]]> 0.203 <![CDATA[Radius a3 / m of Coil 3]]> 0.200 Default position of receiving coil (x0, y0, z0) / m (0.3,0.3,0.3) Default direction of normal vector of receiving coil (A, B, C) (1,2,4)

[0138] Table 2 Centralized COMSOL Simulation Parameter Settings

[0139]

[0140]

[0141] Table 3 Distributed COMSOL Simulation Parameter Settings

[0142]

[0143] By changing the different deflection degrees of the plane of the receiving coil and using the multi-excitation collaborative control method proposed in this example, the curves of the angle change between the direction of the synthetic magnetic field at the center point of the receiving coil and the normal vector of the receiving coil plane can be obtained, respectively, as Figure 10 、 Figure 11 、 Figure 12 shown.

[0144] According to Figures 10 - 12 the numerical simulation results shown, it can be seen that when the receiving coil is deflected at any degree and the system excitation current satisfies the amplitude ratio of multi-excitation collaborative control, the angle between the synthetic magnetic field at the center point position of the system and the normal vector of the coil plane is always zero. That is, the method of multi-excitation collaborative regulation of magnetic energy can achieve that the synthetic magnetic field is always perpendicular to the coil plane, and this method is applicable to the omnidirectional and full-angle wireless power transmission system within the effective energy transfer range.

[0145] According to the above analysis, it can be known that when the relationship between the currents flowing through the multi-excitation coils satisfies the current amplitude ratio relationship proposed in this example, the synthetic magnetic field can be perpendicular to the coil plane. On the premise of ensuring that the total loss of the multi-excitation coils is the same, that is, remaining unchanged, the spatial synthetic magnetic fields of different current working modes of the centralized type and the distributed three orthogonal coils in the collaborative control mode are simulated by using COMSOL finite element software, which more intuitively highlights the perpendicular relationship between the magnetic force lines of the multi-excitation collaborative regulation of magnetic field proposed in this patent and the coil plane, asFigure 13 As shown, where (1) corresponds to exciting only coil 1, (2) corresponds to exciting only coil 2, (3) corresponds to exciting only coil 3, (4) corresponds to exciting coils 1, 2, and 3 in series, (5) corresponds to centralized cooperative control excitation, (6) corresponds to distributed cooperative control excitation, n is the normal vector of the coil plane. The text that cannot be clearly seen in each small figure is "freq(1) = 100kHz", "Streamline type: magnetic field". "freq(1) = 100kHz" indicates that the excitation frequency of each coil is 100kHz, and "Streamline type: magnetic field" indicates that the solid lines other than the coils represent magnetic field lines. Due to software display problems, "I1, I2, I3" respectively represent "I1, I2, I3".

[0146] According to Figure 13 It can be seen from the displayed spatial magnetic field line simulation that the spatial magnetic field lines generated by the coils under the traditional excitation mode do not perpendicularly pass through the coil center, while the spatial magnetic field lines generated by the multi-excitation cooperative magnetic energy regulation method proposed in this example are significantly perpendicular to the coil center. This simulation result is consistent with Equation (2). Regardless of the orientation and angle of the receiving coil, when the current amplitudes of the three coils satisfy the current amplitude ratio of cooperative regulation, the system can achieve the regulation of the magnetic field vector at any center point as expected.

[0147] In summary, the MATLAB theoretical simulation results, COMSOL simulation results are consistent with the theoretical derivation conclusions. Through the multi-excitation magnetic energy regulation method proposed in this embodiment, the combination of three orthogonal coils can achieve the control of the magnetic field direction at any position while minimizing magnetic leakage, and the proposed distributed energy transfer architecture and coil selection criteria can effectively increase the range of the energy transfer space.

[0148] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A full-space magnetic coupling wireless local energy transmission system, characterized in that Including N≥3 three-dimensional orthogonal solid coils; Taking the geometric center of each three-dimensional orthogonal solid coil as the coordinate origin of its respective three-dimensional Cartesian coordinate system, each three-dimensional orthogonal solid coil includes an X-plane orthogonal coil, a Y-plane orthogonal coil, and a Z-plane orthogonal coil that are respectively distributed on the X, Y, and Z coordinate planes and whose geometric centers coincide with the coordinate origin; During wireless power transmission, any X-plane orthogonal coil, any Y-plane orthogonal coil, and any Z-plane orthogonal coil are combined to form a transmitting mechanism for full-space electromagnetic emission.

2. The full-space magnetic-coupling wireless local energy transmission system according to claim 1, wherein: The N X-plane orthogonal coils, N Y-plane orthogonal coils, and N Z-plane orthogonal coils all adopt single transmitting coils with the same structure.

3. The full-space magnetic coupling wireless local energy transmission system according to claim 2, wherein: The current frequencies and phases of the three orthogonal coils in the transmitting mechanism are the same.

4. The full-space magnetic coupling wireless local energy transmission system according to claim 3, wherein: The single transmitting coil adopts a planar coil of any shape.

5. Method for magnetic energy regulation of all - space magnetic - coupled wireless local energy transfer system. For the all - space magnetic - coupled wireless local energy transfer system of claim 3 or 4, it is characterized in that, Including the steps: S1. Determine the structures and positions of the N three-dimensional orthogonal solid coils and the structure and position of the receiving coil according to actual requirements; S2. Determine the expected magnetic field magnitude and direction of the receiving coil according to actual requirements; S3. Take each three-dimensional orthogonal solid coil as a node, and any three single transmitting coils on the X, Y, and Z planes of any node are combined to form a transmitting mechanism, and all transmitting mechanisms are assembled to form a set of transmitting mechanisms; S4. According to the expected magnetic field direction of the receiving coil, based on the principle of minimum magnetic leakage, calculate the current amplitude ratios of the three orthogonal coils of each transmitting mechanism in the set of transmitting mechanisms; S5. Based on the expected magnetic field magnitude of the receiving coil, determine the current amplitudes of the three orthogonal coils of each transmitting mechanism in the set of transmitting mechanisms; S6. Taking the minimum loss as the goal, establish a nonlinear programming model for solution to obtain the optimal node combination and the current amplitudes of the three orthogonal coils in the optimal transmitting mechanism corresponding to this optimal node combination; S7. Excite the three orthogonal coils in the optimal transmitting mechanism with the exciting currents having the current amplitudes calculated in step S6, the same frequency, and the same phase.

6. The magnetic energy regulation method of the full-space magnetic coupling wireless local energy transmission system according to claim 5, characterized in that, In step S3, the set of transmitting mechanisms Q is expressed as: Q = {x|x = [x1,x2,x3], x1,x2,x3 ∈ (1,2,...,N)} Among them, \(x = [x_1, x_2, x_3]\) represents a transmitting mechanism composed of the X-plane orthogonal coil of the \(x_1\)-th node, the Y-plane orthogonal coil of the \(x_2\)-th node, and the Z-plane orthogonal coil of the \(x_3\)-th node. \(N\) is the number of nodes. Therefore, there are a total of transmitting mechanisms in the transmitting mechanism set \(Q\).

7. The magnetic energy regulation method of the all - space magnetic - coupled wireless local energy transmission system according to claim 6, characterized in that, In step S4, according to the expected magnetic field direction of the receiving coil, based on the principle of minimum magnetic leakage, the matrix equation for calculating the current amplitude ratios of the three orthogonal coils in any transmitting mechanism is expressed as follows: where T ui is the current coefficient of the magnetic field component in the u - direction of the orthogonal coil i, represents the normal vector of the plane of the receiving coil, and a, b, and c are the coefficients of the unit vectors in the x, y, and z directions respectively, and I i represents the current amplitude of the orthogonal coil i, is the proportionality coefficient, and H u is the magnetic field component in the u - direction of the total combined magnetic field of the three orthogonal coils. Here, i = 1, 2, 3, u = x, y, z, and the three - dimensional Cartesian coordinate system established is based on the three - dimensional Cartesian coordinate system of any three - dimensional orthogonal solid coil.

8. The magnetic energy regulation method of the full-space magnetic coupling wireless local energy transmission system according to claim 7, characterized in that, The current amplitude ratios of the three orthogonal coils in any transmitting mechanism are expressed as:

9. The magnetic energy regulation method of the all-space magnetic coupling wireless local energy transmission system according to claim 8, characterized in that, In step S5, the current amplitudes of the three orthogonal coils in any transmitting mechanism are expressed as: (I1, I2, I3) = h(H 期望 , (I1 / I2 / I3)) Among them, H 期望 represents the expected magnetic field magnitude of the receiving coil, h(H 期望 , (I1 / I2 / I3)) represents the function between H 期望 and I1 / I2 / I3.

10. The magnetic energy regulation method of the all - space magnetic - coupled wireless local energy transfer system according to claim 9, characterized in that, In step S6, the nonlinear programming model is described as follows: Among them, represents the objective function, R represents the internal resistance of the orthogonal coil i, and r i represents the distance between the orthogonal coil i and the receiving coil in any transmitting mechanism, i = 1, 2, 3, and r max is the maximum effective energy transfer distance, and I coilmax is the maximum current tolerance value of the orthogonal coil.

Images