A self-decoupling coupling mechanism and an anti-offset IPT system constituted thereby

Abstract

The present invention relates to the technical field of wireless power transmission, and specifically discloses a self-decoupling coupling mechanism and an anti-offset IPT system constituted thereby. The transmitting structure and the receiving structure of the self-decoupling coupling mechanism are both composed of a DD-type coil and a flat solenoid coil. These two types of coils can naturally decouple from each other, such that only the mutual inductance between the DD-type coils and the mutual inductance between the flat solenoid coils exist between the transmitting structure and the receiving structure. Moreover, the magnetic field distribution of the coupling mechanism can keep the mutual inductance stable within a certain range when the coupling mechanism at the receiving end of the system is offset, thereby improving the anti-offset ability. For the anti-offset IPT system, by adopting the designed self-decoupling coupling mechanism and designing the primary and secondary resonant networks, the output voltage of the system can be maintained within a certain range under offset conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless power transfer, and particularly to a self-decoupling coupling mechanism and an anti-offset IPT system composed thereof. Background Art

[0002] Wireless power transfer (WPT) technology relies on transmission media such as magnetic fields, electric fields, lasers, and microwaves to achieve non-contact wireless power transfer through the air. In a traditional magnetic coupling wireless power transfer (IPT) system, the coupling mechanism usually consists of two rectangular or circular coils. In practical applications, it is very difficult to make the receiving end and the transmitting end completely face each other. When there is a position offset between the receiving end and the transmitting end, the output parameters of the system will change. As the offset distance increases, the output parameters will drop more sharply, resulting in the system being unable to work properly.

[0003] How to achieve stable output of the coupling mechanism under the offset state is a major problem currently faced. To solve the planar offset problem of the IPT system, many researchers have conducted in-depth studies. They mainly start from the design of the coupling mechanism and the compensation network topology structure to enable the system to resist large planar offsets.

[0004] Currently, the commonly used methods to improve the anti-offset performance are as follows:

[0005] 1. Design of the coupling mechanism: By adding two relay coils between the transmitting coil and the receiving coil, when the receiving end is offset, the system's anti-offset ability is achieved through the compensation of the receiving coil. However, this method greatly increases the sizes of the transmitting coil and the receiving coil;

[0006] 2. Design of the compensation network topology structure: Different topologies are respectively connected in series on the primary and secondary sides to form a hybrid topology to achieve the constant voltage output characteristic. After the system is offset, the mutual inductance changes and their effects cancel each other out to achieve anti-offset. However, this method has a complex structure and is not conducive to practical applications. Summary of the Invention

[0007] The present invention provides a self-decoupling coupling mechanism and an anti-offset IPT system composed thereof, and the technical problem to be solved is: how to provide a new type of coupling mechanism that can have strong anti-offset ability without increasing the sizes of the transmitting coil and the receiving coil, and how to apply this coupling mechanism in the IPT system to achieve constant voltage output.

[0008] To solve the above technical problems, the present invention provides a self-decoupling coupling mechanism, including a transmitting structure and a receiving structure;

[0009] The transmitting structure includes a DD-type transmitting coil and a solenoid-type transmitting coil wound orthogonally around the DD-type transmitting coil to make the transmitting structure a symmetric structure;

[0010] The receiving structure includes a DD-type receiving coil and a solenoid-type receiving coil wound orthogonally around the DD-type receiving coil to make the receiving structure a symmetric structure;

[0011] The DD-type transmitting coil and the DD-type receiving coil are arranged in the same direction.

[0012] Preferably, the solenoid-type transmitting coil is formed by connecting the same first solenoid-type transmitting sub-coil and second solenoid-type transmitting sub-coil in series;

[0013] The solenoid-type receiving coil is formed by connecting the same first solenoid-type receiving sub-coil and second solenoid-type receiving sub-coil in series.

[0014] Preferably, the transmitting structure further includes a primary core, and the receiving structure further includes a secondary core. The transmitting structure is relatively located below the receiving structure. The primary core is located between the lower DD-type transmitting coil and the solenoid-type transmitting coil, and the secondary core is located between the upper DD-type receiving coil and the solenoid-type receiving coil.

[0015] Preferably, the DD-type transmitting coil and the DD-type receiving coil adopt square DD-type coils. The side length of the DD-type coil is D1. The distance from the first solenoid-type transmitting sub-coil or the second solenoid-type transmitting sub-coil to the edge of the DD-type transmitting coil is D2. The distance between the first solenoid-type transmitting sub-coil and the second solenoid-type transmitting sub-coil is D3. The distance from the first solenoid-type receiving sub-coil or the second solenoid-type receiving sub-coil to the edge of the DD-type receiving coil is D4. The distance between the first solenoid-type receiving sub-coil and the second solenoid-type receiving sub-coil is D5. The width of the first solenoid-type transmitting sub-coil or the second solenoid-type transmitting sub-coil is D6. The width of the first solenoid-type receiving sub-coil or the second solenoid-type receiving sub-coil is D7. The number of turns of the DD-type transmitting coil is N 11 The number of turns of the first solenoid-type transmitting sub-coil or the second solenoid-type transmitting sub-coil is N 12 The number of turns of the DD-type receiving coil is N 21 The number of turns of the first solenoid-type receiving sub-coil or the second solenoid-type receiving sub-coil is N 22 Then D1, D2, D3, D4, D5, D6, D7, N 11 、N 12 、N 21, N 22 is determined through the following steps:

[0016] Determine the size of the coupling mechanism, i.e., the value of D1, according to the actual requirements, and determine the transmission distance D according to the actual requirements;

[0017] Configure a reasonable M according to the required transmission power and required transmission efficiency of the system at the transmission distance D 11 and M 22 , M 11 represents the mutual inductance between the DD-type transmitting coil and the DD-type receiving coil, and M 22 represents the mutual inductance between the solenoid-type transmitting coil and the solenoid-type receiving coil;

[0018] Determine the number of turns N through simulation 11 , N 12 , N 21 , N 22 ;

[0019] Determine D2 and D4 according to the offset requirements;

[0020] Determine D6 and D7 according to D6 = N 12 *(r + d), D7 = N 22 *(r + d), where r is the wire diameter of the coil and d is the wire spacing, and r and d are determined according to the actual requirements;

[0021] Determine D3 and D5 according to D3 = D1 - (2 * D6), D5 = D1 - (2 * D7).

[0022] Preferably, the DD-type transmitting coil is connected to the primary LCC-type compensation network to jointly form the first primary resonant circuit, the solenoid-type transmitting coil is connected to the primary compensation capacitor to jointly form the second primary resonant circuit, and the first primary resonant circuit is connected in parallel with the second primary resonant circuit;

[0023] The DD-type receiving coil is connected to the secondary compensation capacitor to jointly form the first secondary resonant circuit, the solenoid-type receiving coil is connected to the secondary LCC-type compensation network to jointly form the second secondary resonant circuit, and the first secondary resonant circuit is connected in series with the second secondary resonant circuit.

[0024] Preferably, the series compensation inductor in the primary LCC-type compensation network is denoted as L f1 , and the series compensation inductor in the secondary LCC-type compensation network is denoted as L f2 , L f1 , L f2 is determined by the following formula:

[0025]

[0026] Among them, U p represents the inverter output voltage at the transmitting end of the system, and U o represents the rectifier input voltage at the receiving end of the system.

[0027] The present invention also provides an anti-offset IPT system composed of a self-decoupling coupling mechanism, which is characterized in that: it includes a transmitting end and a receiving end; the transmitting end includes a DC power supply, an inverter, and a primary resonant circuit, and the receiving end includes a secondary resonant circuit, a rectifier filter circuit, and a load;

[0028] The primary resonant circuit includes a first primary resonant circuit and a second primary resonant circuit connected in parallel to the output end of the inverter. The first primary resonant circuit includes a first primary compensation network and the DD-type transmitting coil connected to each other, and the second primary resonant circuit includes a second primary compensation network and the solenoid-type transmitting coil connected to each other;

[0029] The primary resonant circuit includes a first secondary resonant circuit and a second secondary resonant circuit connected in series with the rectifier filter circuit. The first secondary resonant circuit includes a first secondary resonant network and the DD-type receiving coil connected to each other, and the second secondary resonant circuit includes a second secondary resonant network and the solenoid-type receiving coil connected to each other.

[0030] Preferably, the first primary compensation network adopts a primary LCC-type compensation network, and the second primary compensation network adopts a primary compensation capacitor;

[0031] The first secondary compensation network adopts a secondary compensation capacitor, and the second secondary compensation network adopts a secondary LCC-type compensation network.

[0032] Preferably, the parameters of the primary LCC-type compensation network and the secondary LCC-type compensation network are set through the following steps:

[0033] According to the mutual inductance M 11 between the DD-type transmitting coil and the DD-type receiving coil 22 , and the mutual inductance M between the solenoid-type transmitting coil and the solenoid-type receiving coil, and the formula f1 determine the series compensation inductance L f2 in the primary LCC-type compensation network and the series compensation inductance L

[0034] in the secondary LCC-type compensation network;

[0035] According to the tuning relationship, determine the other parameters of the primary LCC-type compensation network and the secondary LCC-type compensation network.

[0036] A self - decoupling coupling mechanism provided by the present invention, in which both the transmitting structure and the receiving structure are composed of a DD - type coil and a flat solenoid coil. These two types of coils can naturally decouple from each other, such that there is only the mutual inductance between the DD - type coils and the mutual inductance between the flat solenoid coils between the transmitting structure and the receiving structure. Moreover, the magnetic field distribution of this coupling mechanism can keep the mutual inductance stable within a certain range when the coupling mechanism at the receiving end of the system is offset, thereby improving the anti - offset ability.

[0037] An anti - offset IPT system composed of the self - decoupling coupling mechanism provided by the present invention adopts the designed self - decoupling coupling mechanism and can maintain the output voltage within a certain range under the offset condition by designing the primary and secondary resonant networks. Brief Description of the Drawings

[0038] Figure 1 is a perspective view of a self - decoupling coupling mechanism provided by an embodiment of the present invention;

[0039] Figure 2 is a plan view of a self - decoupling coupling mechanism provided by an embodiment of the present invention, where Figure 2 (a) is a top view of the transmitting structure, Figure 2 (b) is a bottom view of the receiving structure;

[0040] Figure 3 is a placement diagram of the positions between the transmitting coils provided by an embodiment of the present invention;

[0041] Figure 4 is a magnetic field distribution diagram of the transmitting structure provided by an embodiment of the present invention, where Figure 4 (a) is a magnetic field distribution diagram of transmitting coil 1, Figure 4 (b) is a magnetic field distribution diagram of transmitting coil 2;

[0042] Figure 5 is an architecture diagram of an anti - offset IPT system applying the self - decoupling coupling mechanism provided by an embodiment of the present invention;

[0043] Figure 6 is provided by an embodiment of the present invention Figure 5 schematic diagram. Detailed Embodiments

[0044] The following specifically illustrates the embodiments of the present invention in conjunction with the drawings. The given embodiments are only for illustrative purposes and should not be construed as a limitation of the present invention. The drawings are only for reference and explanation and do not constitute a limitation on the scope of patent protection of the present invention, because many changes can be made to the present invention without departing from its spirit and scope.

[0045] Example 1

[0046] An embodiment of the present invention provides a self-decoupling coupling mechanism, the structure of which is as Figure 1 shown, including a transmitting structure and a receiving structure. The transmitting structure includes a DD-type transmitting coil (i.e., transmitting coil 1), and a solenoid-type transmitting coil (i.e., transmitting coil 2) orthogonally wound around the DD-type transmitting coil to make the transmitting structure a symmetric structure. The receiving structure includes a DD-type receiving coil (i.e., receiving coil 1), and a solenoid-type receiving coil (i.e., receiving coil 2) orthogonally wound around the DD-type receiving coil to make the receiving structure a symmetric structure;

[0047] The DD-type transmitting coil and the DD-type receiving coil are arranged in the same direction.

[0048] As Figure 1 shown, the solenoid-type transmitting coil is composed of the same first solenoid-type transmitting sub-coil (i.e., transmitting coil 2-1) and second solenoid-type transmitting sub-coil (i.e., transmitting coil 2-2) connected in series;

[0049] The solenoid-type receiving coil is composed of the same first solenoid-type receiving sub-coil (i.e., receiving coil 2-1) and second solenoid-type receiving sub-coil (i.e., receiving coil 2-2) connected in series.

[0050] As Figure 1 shown, in order to increase the magnetic coupling ability, the transmitting structure further includes a primary core, and the receiving structure further includes a secondary core. The transmitting structure is relatively located below the receiving structure, the primary core is located between the lower DD-type transmitting coil and the solenoid-type transmitting coil, and the secondary core is located between the upper DD-type receiving coil and the solenoid-type receiving coil.

[0051] Refer to Figure 2 the plan view, where Figure 2 (a) is the top view of the transmitting structure, Figure 2 (b) is the bottom view of the receiving structure. The parameter definitions of the coupling mechanism shown in this example are as follows:

[0052] The DD-type transmitting coil and the DD-type receiving coil adopt square DD-type coils. The side length of the DD-type coil is D1. The distance between the first solenoid-type transmitting sub-coil or the second solenoid-type transmitting sub-coil and the edge of the DD-type transmitting coil is D2. The distance between the first solenoid-type transmitting sub-coil and the second solenoid-type transmitting sub-coil is D3. The distance between the first solenoid-type receiving sub-coil or the second solenoid-type receiving sub-coil and the edge of the DD-type receiving coil is D4. The distance between the first solenoid-type receiving sub-coil or the second solenoid-type receiving sub-coil is D5. The width of the first solenoid-type transmitting sub-coil or the second solenoid-type transmitting sub-coil is D6. The width of the first solenoid-type receiving sub-coil or the second solenoid-type receiving sub-coil is D7. The number of turns of the DD-type transmitting coil is N 11, the number of turns of the first solenoid-type transmitting sub-coil or the second solenoid-type transmitting sub-coil is N 12 , the number of turns of the DD-type receiving coil is N 21 , the number of turns of the first solenoid-type receiving sub-coil or the second solenoid-type receiving sub-coil is N 22 .

[0053] For the convenience of analysis, the positions of the transmitting coils are placed as Figure 3 shown. The transmitting coil 1 and the transmitting coil 2 are symmetrically designed. They are placed at the same center point O. I1 and I2 respectively represent the excitation current vectors flowing through the transmitting coil 1 and the transmitting coil 2. and respectively represent the angles between any point on the transmitting coil 1 and the transmitting coil 2 and the X-axis.

[0054] According to the Neumann formula, the mutual inductance value M between coil i and coil j ij can be expressed as:

[0055]

[0056] L i and L j respectively represent the length vectors of coil i and coil j, r ij represents the distance between dL i and dL j ; μ0 is the vacuum permeability, and N1 and N2 respectively represent the number of turns of the transmitting coil 1 and the transmitting coil 2. The mutual inductance between the transmitting coil 1 and the transmitting coil 2 can be expressed as:

[0057] M 12 = M 1-2L + M 1-2R (2)

[0058] 2L represents the left half of the transmitting coil 2, that is, the transmitting coil 2-1, and 2R represents the right half of the transmitting coil 2, that is, the transmitting coil 2-2. Then M 1-2L represents the mutual inductance between the transmitting coil 1 and the left half of the transmitting coil 2, and M 1-2R represents the mutual inductance between the transmitting coil 1 and the right half of the transmitting coil 2.

[0059] According to Equation (2), the mutual inductance of Equation (1) can be expressed as:

[0060]

[0061]

[0062] where x′ i and y′ i respectively represent x i and y iThe derivative, where i = 1, 2;

[0063]

[0064] (x i , y i ) represents a point on coil i, and (x j , y j ) represents a point on coil j. The two points are on the same vertical line of the two coils.

[0065] The integration directions of Equation (3) and Equation (4) are determined by the winding direction of the coil, that is, the reference direction of the current. Using the numerical integration function in MATLAB to solve Equation (3) and Equation (4), we can obtain:

[0066]

[0067] It can be seen from Equation (6) that the transmitting coil 1 and the transmitting coil 2 are decoupled from each other. The conditions for the equation to hold are independent of the relative magnitudes of D1, D2, and D3 and also independent of whether the transmitting coil 2 is in the middle or on either side. Therefore, the decoupling conditions of the two transmitting coils have no direct relationship with their sizes and vertical positions.

[0068] Figure 4 is the magnetic field distribution diagram of the transmitting structure, where Figure 4 (a) is the magnetic field distribution diagram of the transmitting coil 1, Figure 4 (b) is the magnetic field distribution diagram of the transmitting coil 2. It can be seen from Figure 4 (a) that the magnetic field of the transmitting coil 1 mainly follows the X direction. It can be seen from Figure 4 (b) that the magnetic field of the transmitting coil 2 mainly follows the Y direction. The magnetic fields between the two transmitting coils are cross - coupled at 90° and decoupled from each other.

[0069] The parameters of the coupling mechanism D1, D2, D3, D4, D5, D6, D7, N 11 , N 12 , N 21 , N 22 are determined through the following steps:

[0070] Determine the size of the coupling mechanism, that is, the value of D1, according to the actual requirements, and determine the transmission distance D according to the actual requirements;

[0071] Configure reasonable M 11 and M 22 , where M 11 represents the mutual inductance between the DD - type transmitting coil and the DD - type receiving coil, and M 22 represents the mutual inductance between the solenoid - type transmitting coil and the solenoid - type receiving coil;

[0072] Determine the number of turns N through simulation 11 , N 12 , N 21 , N 22 ;

[0073] Determine D2 and D4 according to the offset requirements;

[0074] According to D6 = N 12 *(r + d), D7 = N 22 *(r + d) to determine D6 and D7, where r is the wire diameter of the coil and d is the wire spacing, and r and d are determined according to actual requirements;

[0075] Determine D3 and D5 according to D3 = D1 - (2 * D6), D5 = D1 - (2 * D7).

[0076] As an application example, applying the coupling mechanism provided by the present invention in an electric vehicle wireless charging system, the architecture of the system is as Figure 5 shown, and the circuit principle is as Figure 6 shown. The DD - type transmitting coil and the primary - side LCC - type compensation network are jointly used as the first primary - side resonant circuit, and the solenoid - type transmitting coil and the primary - side compensation capacitor are jointly used as the second primary - side resonant circuit. The first primary - side resonant circuit and the second primary - side resonant circuit are in parallel. The DD - type receiving coil and the secondary - side compensation capacitor are jointly used as the first secondary - side resonant circuit, and the solenoid - type receiving coil and the secondary - side LCC - type compensation network are jointly used as the second secondary - side resonant circuit. The first secondary - side resonant circuit and the second secondary - side resonant circuit are in series. Among them, the series compensation inductor in the primary - side LCC - type compensation network is denoted as L f1 , and the series compensation inductor in the secondary - side LCC - type compensation network is denoted as L f2 , the mutual inductance between the DD - type transmitting coil and the DD - type receiving coil is denoted as M 11 , and the mutual inductance between the solenoid - type transmitting coil and the solenoid - type receiving coil is denoted as M 22 .

[0077] The embodiment of the present invention adopts a dual - transmitting and dual - receiving mode. The primary - side compensation network adopts a parallel mode of LCC and S networks, and the secondary - side compensation network adopts a series mode of S and LCC to ensure that the two transmitting coils can simultaneously transmit energy and the two receiving coils can simultaneously receive energy. The electrical parameters of the system are defined in Table 1, where i = 1, 2; j = 1, 2, 3, 4.

[0078] Table 1 Definition of electrical parameters

[0079]

[0080] According to the coupling mechanism model, the DD coil and the flat spiral coil on the same side are decoupled. At the same time, in any case of plane offset, the DD coil at the transmitting end and the flat spiral coil at the receiving end, as well as the flat spiral coil at the transmitting end and the DD coil at the receiving end, are also decoupled. Therefore, there are only 2 pairs of mutual inductances in the system, namely L p1 and L s1 The mutual inductance M 11 between them and L p2 and L s2 The mutual inductance M 22 .

[0081] On the primary side, the inductor L f1 and the capacitor C f1 form a resonant network. The primary main coil L P and the capacitor C p , C f1 form a resonant network. On the secondary side, the secondary main coil L s and the capacitor C s , C f2 form a resonant network. The inductor L f2 and the capacitor C f2 form a resonant network. From this, we can obtain:

[0082]

[0083] Writing the KVL equation for the LCC-S / S-LCC composite topology, we can obtain:

[0084]

[0085] Substituting Equation (7) into Equation (8) and simplifying, we get:

[0086]

[0087] It can be seen from Equation (9) that the output voltage of the system is independent of the equivalent load resistance R L , and the system can achieve constant voltage output. When the system has an offset, U o is proportional to M 11 and inversely proportional to M 22 . When M 11 and M 22 increase or decrease simultaneously, the effects of M 11 and M 22 on U o are exactly opposite, and they play an inhibitory role in the change of U o . Therefore, by reasonably configuring the values of M 11 , M 22 , L f1 and L f2 , the output voltage U of the system can be made under offset conditionso is maintained within a certain range. Specifically, L f1 、L f2 is determined by the following formula:

[0088]

[0089] U p represents the inverter output voltage at the transmitting end of the system, and U o represents the rectifier input voltage at the receiving end of the system.

[0090] In summary, a self-decoupling coupling mechanism provided by an embodiment of the present invention has a transmitting structure and a receiving structure both composed of a DD-type coil and a flat solenoid coil. These two coils can naturally decouple from each other, such that there is only the mutual inductance between the DD-type coils and the mutual inductance between the flat solenoid coils between the transmitting structure and the receiving structure. Moreover, the magnetic field distribution of this coupling mechanism can keep the mutual inductance stable within a certain range when the coupling mechanism at the receiving end of the system is offset, thereby improving the anti-offset ability.

[0091] Example 2

[0092] This embodiment provides an anti-offset IPT system composed of the self-decoupling coupling mechanism shown in Embodiment 1. As Figure 5 、 Figure 6 shown, it includes a transmitting end and a receiving end. The transmitting end includes a DC power supply, an inverter, and a primary resonant circuit. The receiving end includes a secondary resonant circuit, a rectifier filter circuit (including a rectifier and a filter capacitor), and a load.

[0093] The primary resonant circuit includes a first primary resonant circuit and a second primary resonant circuit connected in parallel to the output end of the inverter. The first primary resonant circuit includes a first primary compensation network and a DD-type transmitting coil connected to each other. The second primary resonant circuit includes a second primary compensation network and a solenoid-type transmitting coil connected to each other.

[0094] This system adopts the same resonant network as in Embodiment 1. Specifically, the primary resonant circuit includes a first secondary resonant circuit and a second secondary resonant circuit connected in series with the rectifier filter circuit. The first secondary resonant circuit includes a first secondary resonant network and a DD-type receiving coil connected to each other. The second secondary resonant circuit includes a second secondary resonant network and a solenoid-type receiving coil connected to each other.

[0095] In this system, the first primary compensation network adopts a primary LCC-type compensation network, and the second primary compensation network adopts a primary compensation capacitor;

[0096] The first secondary compensation network adopts a secondary compensation capacitor, and the second secondary compensation network adopts a secondary LCC-type compensation network.

[0097] The parameters of the primary resonant circuit and the secondary resonant circuit are determined through the following steps:

[0098] According to actual needs and the formula L f1 and L f2 are determined;

[0099] ω can be determined according to the actual operating frequency of the system;

[0100] According to the above resonance relationship, other parameters of the primary LCC-type compensation network and the secondary LCC-type compensation network can be determined, and the primary compensation capacitor and the secondary compensation capacitor can be determined:

[0101]

[0102] Except for the DC power supply, the inverter, and the rectifier filter circuit part, the rest of the system is the same as that in Embodiment 1. Therefore, the same content will not be repeated in this embodiment.

[0103] An anti-offset IPT system composed of a self-decoupling coupling mechanism provided by an embodiment of the present invention adopts the designed self-decoupling coupling mechanism and can maintain the output voltage within a certain range under the offset condition by designing the primary and secondary resonant networks.

[0104] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited by 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 self-decoupling coupling mechanism, characterized in that, It includes a transmitting structure and a receiving structure; The transmitting structure includes a DD-type transmitting coil, and a solenoid-type transmitting coil orthogonally wound around the DD-type transmitting coil to make the transmitting structure a symmetric structure; The receiving structure includes a DD-type receiving coil, and a solenoid-type receiving coil orthogonally wound around the DD-type receiving coil to make the receiving structure a symmetric structure; The DD-type transmitting coil and the DD-type receiving coil are arranged in the same direction; The solenoid-type transmitting coil is formed by connecting the same first solenoid-type transmitting sub-coil and second solenoid-type transmitting sub-coil in series; The solenoid-type receiving coil is formed by connecting the same first solenoid-type receiving sub-coil and second solenoid-type receiving sub-coil in series; The DD-type transmitting coil and the DD-type receiving coil adopt square DD-type coils. The side length of the DD-type coil is D1. The distance from the first solenoid-type transmitting sub-coil or the second solenoid-type transmitting sub-coil to the edge of the DD-type transmitting coil is D2. The distance between the first solenoid-type transmitting sub-coil and the second solenoid-type transmitting sub-coil is D3. The distance from the first solenoid-type receiving sub-coil or the second solenoid-type receiving sub-coil to the edge of the DD-type receiving coil is D4. The distance between the first solenoid-type receiving sub-coil and the second solenoid-type receiving sub-coil is D5. The width of the first solenoid-type transmitting sub-coil or the second solenoid-type transmitting sub-coil is D6. The width of the first solenoid-type receiving sub-coil or the second solenoid-type receiving sub-coil is D7. The number of turns of the DD-type transmitting coil is N 11 , the number of turns of the first solenoid-type transmitting sub-coil or the second solenoid-type transmitting sub-coil is N 12 , the number of turns of the DD-type receiving coil is N 21 , the number of turns of the first solenoid-type receiving sub-coil or the second solenoid-type receiving sub-coil is N 22 , then D1, D2, D3, D4, D5, D6, D7, N 11 , N 12 , N 21 , N 22 are determined through the following steps: Determine the size of the coupling mechanism, i.e., the value of D1, according to actual requirements, and determine the transmission distance D according to actual requirements; Configure a reasonable M according to the required transmission power and required transmission efficiency of the system at the transmission distance D 11 and M 22 , M 11 represents the mutual inductance between the DD-type transmitting coil and the DD-type receiving coil, M 22 represents the mutual inductance between the solenoid-type transmitting coil and the solenoid-type receiving coil; Determine the number of turns N through simulation 11 、N 12 、N 21 、N 22 ; Determine D2 and D4 according to the offset requirements; According to D6 = N 12 *(r + d), D7 = N 22 *(r + d) to determine D6 and D7, where r is the wire diameter of the coil, d is the wire pitch, and r and d are determined according to actual requirements; Determine D3 and D5 according to D3 = D1-(2*D6) and D5 = D1-(2*D7).

2. An auto-decoupling coupling mechanism according to claim 1, wherein: The transmitting structure further includes a primary core, the receiving structure further includes a secondary core, the transmitting structure is relatively located below the receiving structure, the primary core is located between the lower DD-type transmitting coil and the solenoid-type transmitting coil, and the secondary core is located between the upper DD-type receiving coil and the solenoid-type receiving coil.

3. An auto-decoupling coupling mechanism according to claim 1, wherein: The DD-type transmitting coil is connected to a primary LCC-type compensation network to jointly form a first primary resonant circuit, the solenoid-type transmitting coil is connected to a primary compensation capacitor to jointly form a second primary resonant circuit, and the first primary resonant circuit and the second primary resonant circuit are connected in parallel; The DD-type receiving coil is connected to a secondary compensation capacitor to jointly form a first secondary resonant circuit, the solenoid-type receiving coil is connected to a secondary LCC-type compensation network to jointly form a second secondary resonant circuit, and the first secondary resonant circuit and the second secondary resonant circuit are connected in series.

4. The self-decoupling coupling mechanism according to claim 3, wherein: The series compensation inductance in the primary - side LCC compensation network is expressed as L f1 , and the series compensation inductance in the secondary - side LCC compensation network is expressed as L f2 , L f1 、 L f2 which is determined by the following formula: ， Among them, U p represents the inverter output voltage at the transmitting end of the system, and U o represents the rectifier input voltage at the receiving end of the system.

5. An anti-offset IPT system composed of the self-decoupling coupling mechanism according to any one of claims 1 to 4, characterized in that: It includes a transmitting end and a receiving end; the transmitting end includes a DC power supply, an inverter, and a primary resonant circuit, and the receiving end includes a secondary resonant circuit, a rectifying and filtering circuit, and a load; The primary resonant circuit includes a first primary resonant circuit and a second primary resonant circuit connected in parallel to the output end of the inverter. The first primary resonant circuit includes a first primary compensation network and the DD-type transmitting coil connected together, and the second primary resonant circuit includes a second primary compensation network and the solenoid-type transmitting coil connected together; The secondary resonant circuit includes a first secondary resonant circuit and a second secondary resonant circuit connected in series with the rectifying and filtering circuit. The first secondary resonant circuit includes a first secondary resonant network and the DD-type receiving coil connected together, and the second secondary resonant circuit includes a second secondary resonant network and the solenoid-type receiving coil connected together.

6. An anti-offset IPT system composed of an auto-decoupling coupling mechanism according to claim 5, wherein: The first primary-side compensation network adopts a primary-side LCC-type compensation network, and the second primary-side compensation network adopts a primary-side compensation capacitor; The first secondary-side compensation network adopts a secondary-side compensation capacitor, and the second secondary-side compensation network adopts a secondary-side LCC-type compensation network.

7. An anti-offset IPT system composed of a self-decoupling coupling mechanism according to claim 6, characterized in that, The parameters of the primary-side LCC-type compensation network and the secondary-side LCC-type compensation network are set through the following steps: According to the mutual inductance between the DD-type transmitting coil and the DD-type receiving coil M 11 and the mutual inductance between the solenoid-type transmitting coil and the solenoid-type receiving coil M 22 , and formula determine the series compensation inductance in the primary side LCC-type compensation network L f1 and the series compensation inductance in the secondary side LCC-type compensation network L f2 ; Determine other parameters of the primary-side LCC-type compensation network and the secondary-side LCC-type compensation network according to the resonance relationship.

8. An anti-offset IPT system composed of a self-decoupling coupling mechanism according to claim 7, characterized in that Determine the primary-side compensation capacitor and the secondary-side compensation capacitor according to the resonance formula.

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