A wide-distance adaptive wireless power transmission device based on dual-coupling coils

Abstract

The present invention proposes a wide-distance adaptive wireless power transmission device based on dual coupling coils. The wireless power transmission device includes a transmitting side and a receiving side, and the transmitting side and the receiving side are arranged relative to each other to form coupled induction; wherein the transmitting side includes a coupling coil L f , coupling coil L p , transmitting compensation coil L f1 , transmitter compensation capacitor C fp , DC power supply and inverter circuit; the receiving side includes a receiving coil L s , receiving compensation capacitor C s , rectifier filter circuit and equivalent load R L .

Description

Technical Field

[0001] The present invention provides a wide-distance adaptable wireless power transmission device based on dual coupling coils, belonging to the technical field of wireless power transmission. Background Art

[0002] Wireless power transmission technology breaks free from the constraints of cables. The magnetic coupling mechanism maintains a certain transmission distance between the transmitting and receiving sides, but lacks a physical connection. This makes the coils on both sides susceptible to misalignment, a characteristic of wireless power transmission systems. Changes in the relative position between the transmitting and receiving sides can cause fluctuations in mutual inductance, leading to unstable output and reduced system efficiency. These changes in relative position not only include radial misalignment of the coupling mechanism, but also the vertical distance between the axial directions of the transmitting and receiving sides. To ensure stable system operation and efficient energy transmission, a wide-range adaptable wireless power transmission device and parameter design method with strong misalignment and vertical distance adaptability are urgently needed to achieve efficient and stable energy output despite changes in misalignment and transmission distance. Summary of the Invention

[0003] The purpose of this invention is to solve the problem of unstable output caused by offset and vertical distance changes in existing wireless power transmission systems. A wide-distance adaptive wireless power transmission device based on dual-coupled coils and a parameter design method are proposed. Without the need for complex control circuits, the coil structure, compensation topology, and parameter design of the wireless power transmission device enable the system to have a constant output capacity and achieve stable energy transmission over a wide distance range. The technical solutions adopted are as follows:

[0004] A wide-distance adaptive wireless power transmission device based on dual coupling coils, the wireless power transmission device includes a transmitting side and a receiving side, and the transmitting side and the receiving side are arranged relative to each other to form coupled induction; wherein the transmitting side includes a coupling coil L f , coupling coil L p , transmitting compensation coil L f1 , transmitter compensation capacitor C fp , DC power supply and inverter circuit; the receiving side includes a receiving coil L s , receiving compensation capacitor C s , rectifier filter circuit and equivalent load R L .

[0005] Furthermore, the coupling coil L f and coupling coilL p The coupling coil is coplanarly arranged on the planar magnetic core, and the coupling coil L f With receiving coil L s Mutual induction M fs The degree of change with offset distance ∂ M fs / ∂ y And the degree of change with transmission distance ∂ M fs / ∂ z Greater than the coupling coil L p With receiving coil L s Mutual induction M ps The degree of change with offset distance ∂ M ps / ∂ y And the degree of change with transmission distance ∂ M ps / ∂ z , that is, satisfying ∂ M fs / ∂ y >∂ M ps / ∂ y , ∂ M fs / ∂ z >∂ M ps / ∂ z .

[0006] Furthermore, the coupling coil L f The coupling coil is located inside the plane of the coupling mechanism on the transmitting side. L p Located outside the plane of the transmitting side coupling mechanism, and the coupling coil L f and coupling coil L p It adopts concentric ring structure.

[0007] Furthermore, the coupling coil L f The non-identical end and the coupling coil L p The transmitting compensation coil L f1 One end is connected to the output terminal A of the inverter circuit, and the other end is connected to the coupling coil L fThe same-name terminal is connected; the transmitting compensation capacitor C fp One end is connected to the output terminal B of the inverter circuit, and the other end is connected to the coupling coil L f With coupling coil L p The common connection points are connected.

[0008] Furthermore, the transmitting compensation coil L f1 and coupling coil L f Located on the transmitting side parallel branch I; the transmitting compensation capacitor C fp Located on the transmitting side parallel branch II; the coupling coil L p Located on the transmitting side parallel branch III; and the transmitting side parallel branch I is inductive; the transmitting side parallel branch III is inductive; the equivalent inductance of the transmitting side parallel branch I L fe Greater than the equivalent inductance of the transmitter-side parallel branch III L pe .

[0009] Furthermore, the receiving coil L s and receiving compensation capacitors C s and system operating frequency oh satisfy oh =1 / ( L s C s ) 0.5 .

[0010] Furthermore, the parameter design method of the wireless power transmission device includes:

[0011] Step 1: setting circuit parameters of the wireless power transmission device, wherein the circuit parameters include all coupling relationship models included in the wireless power transmission device;

[0012] Step 2: Setting coil parameters of the wireless power transmission device;

[0013] Step 3: Setting topology compensation parameters for the wireless power transmission device.

[0014] Furthermore, the circuit parameters of the wireless power transmission device described in step 1 are set, wherein the circuit parameters include all coupling relationship models contained in the wireless power transmission device, including:

[0015] Step 101: Establishing an equivalent circuit model of a wide-distance adaptive wireless power transmission system with dual coupled coils;

[0016] Step 102: Calculate the relationship between each loop current and the coupling mechanism parameters. The relationship model is:

[0017]

[0018] in, M fs For coupling coil L f With receiving coil L s Mutual induction, M ps For coupling coil L p With receiving coil L s Mutual induction, M fp For coupling coil L f With coupling coil L p The mutual induction between α = - ( M fs + M ps ) 2 oh + oh 3 ( M ps 2 L fe + M fs 2 L pe ) C e , β = R EF ( L fe (-1+ oh 2 L pe C e )- L pe ), L fe = L f1 + L f+ M fp , L pe = L p + M fp , oh is the system operating frequency, C e is the equivalent capacitance of the transmitting side parallel branch II, U s is the inverter output voltage, R EF Input equivalent AC resistance for the rectifier bridge;

[0019] Step 103: Calculate Capacitance C e The relationship between the coupling mechanism parameters is as follows:

[0020]

[0021] Among them, the regulatory factor ;

[0022] Step 104: Calculate the compensation coil of the transmitting-side parallel branch I L f1 The relationship between the coupling mechanism parameters is as follows:

[0023]

[0024] Step 105: Calculate the compensation capacitance of the transmitter-side parallel branch II C fp The relationship between the coupling mechanism parameters is as follows:

[0025]

[0026] Step 106: Calculate the load current I oN The relationship between the coupling mechanism parameters is as follows:

[0027]

[0028] in, U d is the inverter DC input voltage, M eq is the equivalent mutual inductance between the transmitting and receiving sides, defined as M eq = M fs - λM ps ;

[0029] Step 107: Calculate System AC Efficiency or The relationship between the coupling mechanism parameters is as follows:

[0030]

[0031] in, R Lf 、 R Lp 、 R Ls For coupling coil L f , coupling coil L p , receiving coil L s The internal resistance of the coil;

[0032] Step 108: Calculate the optimal AC resistance corresponding to the maximum system AC efficiency R EF_opt The relationship between the coupling mechanism parameters is as follows:

[0033]

[0034] Step 109: Calculate the system's maximum AC efficiency or max The relationship between the coupling mechanism parameters is as follows:

[0035]

[0036] Step 1010: Calculate rated output power P oN The relationship between the optimal AC internal resistance and the coupling mechanism parameters is as follows:

[0037]

[0038] Step 1011: Calculate the equivalent mutual inductance required to meet the rated output power and maximize efficiency.

[0039]

[0040] Furthermore, the step 2 of setting the coil parameters of the wireless power transmission device includes:

[0041] Step 201: Determine the coupling coil L p and receiving coil L s Outer diameter R p 、 R s and number of turnsN p 、 N s ;

[0042] Step 202: Determine the coupling coil L f Minimum inner diameter r f ;

[0043] Step 203: Calculate the coupling coil L f Maximum number of turns under the current inner diameter N max =( R p - N p * D _wire - r f ) / D _wire ,in, D _wire is the diameter of the Litz wire;

[0044] Step 204: Coupling Coil L f Number of turns N f Calculate the offset distance starting from 2 and increasing to the maximum value under the current inner diameter D y and vertical change distance D z Under this condition, the mutual inductance change rate ∂ M fs / ∂ y , ∂ M ps / ∂ y , ∂ M fs / ∂ z , ∂ M ps / ∂ z ;

[0045] Step 205: Enlarge the coupling coil L f Inner diameter r f , to determine whether the inequality is satisfied r f < R p - N p × D _wire If satisfied, add weight to calculate coupling coilL f Maximum number of turns under the current inner diameter N max =( R p - N p * D _wire - r f ) / D _wire , repeat step 204, if not satisfied, proceed to step 206;

[0046] Step 206: Calculate the difference r f and N f Under the mutual induction when the offset and vertical distance change M fs and M ps The ratio of the rate of change is shown below:

[0047]

[0048] Step 207: Select l , l z < λ<λ y , and satisfies the formula and (1- d ) I oN < I oN <(1+ d ) I oN ,in, d is the preset current change percentage.

[0049] Furthermore, the step 3 of setting the topology compensation parameters for the wireless power transmission device includes:

[0050] Step 301: Using the formula and , calculate the compensation coil of the parallel branch I on the transmitting side L f1 and the compensation capacitor of the transmitter-side parallel branch II C fp ;

[0051] Step 302: Calculate receiving compensation capacitance C s =1 / ( ωL s )2 .

[0052] Beneficial effects of the present invention:

[0053] Against the backdrop of improving wireless power transmission performance, the present invention proposes a wide-distance adaptive wireless power transmission device and parameter design method based on dual-coupling coils. This device is designed based on the fact that the transceiver side of the actual system is prone to offset and the vertical distance is not fixed. The parameters are designed according to actual needs, resulting in high practicality. Furthermore, the introduction of the adjustment factor λ significantly increases the design freedom of the system parameters. Compared to existing anti-offset systems, the present invention improves the anti-offset characteristics of electric energy while also improving the system's adaptability to vertical distance changes. Compared to existing two-coil systems on the transmitting side, the coupling coils Lf and Lp of the present invention are located on different branches, each participating in the coupling effect with the receiving coil Ls, increasing the flexibility of system parameter design. It should be noted that the equivalent mutual inductance between the transceiver coils of the present invention can be flexibly designed according to actual operating conditions, and the equivalent mutual inductance can be greater than the mutual inductance between any coils, achieving stable output characteristics while improving the system's transmission efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 This is a circuit diagram of a wide-distance adaptive wireless power transmission device based on dual-coupling coils according to the present invention;

[0055] Figure 2 A schematic diagram of the coupling mechanism structure provided for the implementation of the present invention;

[0056] Figure 3 This is a flow chart of a parameter design method for a wide-distance adaptive wireless power transmission device based on dual-coupling coils;

[0057] Figure 4 Curves showing how the mutual inductance of the transceiver coils changes with offset and vertical distance, provided for the implementation of the present invention, including: (a) a curve showing how the mutual inductance changes with offset distance Dy; (b) a curve showing how the mutual inductance changes with vertical distance Dz;

[0058] Figure 5 Curves showing how the equivalent mutual inductance changes with offset and vertical distance after the adjustment factor is introduced for the present invention, including (a) the curve showing how the mutual inductance changes with offset distance Dy; and (b) the curve showing how the mutual inductance changes with vertical distance Dz. DETAILED DESCRIPTION

[0059] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0060] Example 1

[0061] This embodiment proposes a wide-distance adaptive wireless power transmission device based on dual coupling coils, such as Figure 1 and Figure 2 As shown, the wireless power transmission device includes a transmitting side and a receiving side, and the transmitting side includes a coupling coil. L f , coupling coil L p , transmitting compensation coil L f1 , transmitter compensation capacitor C fp , DC power supply and inverter circuit; the receiving side includes a receiving coil L s , receiving compensation capacitor C s , rectifier filter circuit and equivalent load R L Specifically, the coupling coil L f , coupling coil L p and receiving coil L s All of them are circular coil structures with magnetic cores.

[0062] Wherein, the coupling coil L f , coupling coil L p Coplanar placement; the coupling coil L f Located inside the coupling mechanism on the transmitting side, the coupling coil L p Located outside the transmitting side coupling mechanism; the coupling coil L f and coupling coil L p Participating and receiving coils L s coupling; the coupling coil L f The non-identical end and the coupling coil L p The transmitting compensation coil L f1 One end is connected to the output terminal A of the inverter circuit, and the other end is connected to the coupling coil L f The same-name terminal is connected; the transmitting compensation capacitor C fp One end is connected to the output terminal B of the inverter circuit, and the other end is connected to the coupling coil L f With coupling coilL p The transmitting compensation coil is connected to the common connection point; L f1 and coupling coil L f Located on the transmitting side parallel branch I;

[0063] Wherein, the transmitting compensation capacitor C fp Located on the transmitting side parallel branch II; the coupling coil L p Located on the transmitting side parallel branch III;

[0064] The receiving coil L s , receiving compensation capacitor C s and system operating frequency oh satisfy oh =1 / ( L s C s ) 0.5 ;

[0065] The equivalent inductance of the transmitting side parallel branch I L fe Greater than the equivalent inductance of the transmitter-side parallel branch III L pe ;

[0066] The coupling coil L f With receiving coil L s Mutual induction M fs The degree of change with offset distance ∂ M fs / ∂ y And the degree of change with transmission distance ∂ M fs / ∂ z Greater than the coupling coil L p With receiving coil L s Mutual induction M ps The degree of change with offset distance ∂ M ps / ∂ y And the degree of change with transmission distance ∂ M ps / ∂ z , that is, satisfying ∂ M fs / ∂y >∂ M ps / ∂ y , ∂ M fs / ∂ z >∂ M ps / ∂ z ;

[0067] The wide-distance adaptive wireless power transmission device based on dual coupling coils described in this embodiment improves the system's anti-device performance and adaptability to vertical distance changes compared to the anti-device devices in existing research. The two coupling coils on the transmitting side are located on different branches, each participating in the coupling with the receiving coil, thereby improving the flexibility of parameter design.

[0068] Example 2

[0069] This embodiment proposes a parameter design method for a wide-distance adaptive wireless power transmission device based on dual-coupling coils, including:

[0070] Step 1: setting circuit parameters of the wireless power transmission device, wherein the circuit parameters include all coupling relationship models included in the wireless power transmission device;

[0071] Step 2: Setting coil parameters of the wireless power transmission device;

[0072] Step 3: Setting topology compensation parameters for the wireless power transmission device.

[0073] The circuit parameters of the wireless power transmission device are set in step 1, wherein the circuit parameters include all coupling relationship models included in the wireless power transmission device, including:

[0074] Step 101: Establishing an equivalent circuit model of a wide-distance adaptive wireless power transmission system with dual coupled coils;

[0075] Step 102: According to Kirchhoff's law, the relationship between the current of each loop and the coupling mechanism parameters is calculated. The relationship model is: (1.1)

[0076] in, M fs For coupling coil L f With receiving coil L s Mutual induction, M ps For coupling coil L p With receiving coil Ls Mutual induction, M fp For coupling coil L f With coupling coil L p The mutual induction between α = - ( M fs + M ps ) 2 oh + oh 3 ( M ps 2 L fe + M fs 2 L pe ) C e , β = R EF ( L fe (-1+ oh 2 L pe C e )- L pe ), L fe = L f1 + L f + M fp , L pe = L p + M fp , oh is the system operating frequency, C e is the equivalent capacitance of the transmitting side parallel branch II, U s is the inverter output voltage, R EF Input equivalent AC resistance for the rectifier bridge;

[0077] Step 103: Calculate Capacitance C e The relationship between the coupling mechanism parameters is as follows:

[0078] (1.2)

[0079] in, , defined as the regulating factor, and l >1;

[0080] Step 104: Substituting equation (1.2) into equation (1.1) yields the relationship between each loop current and the coupling mechanism parameters. The relationship model is:

[0081] (1.3)

[0082] Step 105: Calculate the compensation coil of the transmitting-side parallel branch I according to the adjustment factor L f1 The relationship between the coupling mechanism parameters is as follows:

[0083] (1.4)

[0084] Step 106: Mutual Inductance M fp The equivalent capacitance generated in the parallel branch II is 1 / ( oh 2 M fp ), then the compensation capacitor of the parallel branch II on the transmitting side C fp for

[0085] (1.5)

[0086] Step 107: Based on the fundamental wave equivalent principle, calculate the relationship between the load current and the coupling mechanism parameters. The relationship model is:

[0087] (1.6)

[0088] in, U d is the inverter DC input voltage, M eq = M fs - λM ps ;

[0089] Step 108: Calculate System AC Efficiency or The relationship between the coupling mechanism parameters is as follows:

[0090] (1.7)

[0091] in, R Lf 、R Lp 、 R Ls For coupling coil L f , coupling coil L p , receiving coil L s The internal resistance of the coil;

[0092] Step 109: From equation (1.7), we can get the optimal AC internal resistance when the system AC efficiency is the maximum. (1.8)

[0093] Step 1010: Substituting equation (1.8) into equation (1.7), we can get the maximum AC efficiency of the system: (1.9)

[0094] Step 1011: Calculate rated output power P oN The corresponding optimal AC internal resistance is:

[0095] (1.10)

[0096] Step 1012: To maximize the system AC efficiency at rated power, the equivalent mutual inductance must satisfy the following equations (1.8) and (1.10):

[0097] (1.11)

[0098] Specifically, the step 2 of setting the coil parameters of the wireless power transmission device includes:

[0099] Step 201: Determine the coupling coil L p and receiving coil L s Outer diameter R p 、 R s and number of turns N p 、 N s ;

[0100] Step 202: Determine the coupling coil L f Minimum inner diameter r f ;

[0101] Step 203: Calculate the coupling coil L f Maximum number of turns under the current inner diameterN max =( R p - N p * D _wire - r f ) / D _wire ,in, D _wire is the diameter of the Litz wire;

[0102] Step 204: Coupling Coil L f Number of turns N f Calculate the offset distance starting from 2 and increasing to the maximum value under the current inner diameter D y and vertical change distance D z Under this condition, the mutual inductance change rate ∂ M fs / ∂ y , ∂ M ps / ∂ y , ∂ M fs / ∂ z , ∂ M ps / ∂ z ;

[0103] Step 205: Enlarge the coupling coil L f Inner diameter r f , to determine whether the inequality is satisfied r f < R p - N p × D _wire If satisfied, add weight to calculate coupling coil L f Maximum number of turns under the current inner diameter N max =( R p - N p * D _wire - r f ) / D _wire , repeat step 204, if not satisfied, proceed to step 206;

[0104] Step 206: Calculate the difference r f and N f Under the mutual induction when the offset and vertical distance change M fs and M ps The ratio of the rate of change is shown below: (2.1)

[0105] Step 207: Select l , l z < λ<λ y , and satisfy formula (1.11) and (1- d ) I oN < I oN <(1+ d ) I oN ,in, d is the preset current change percentage.

[0106] Specifically, the step 3 of setting the topology compensation parameters for the wireless power transmission device includes:

[0107] Step 301: Using the formula and , calculate the compensation coil of the parallel branch I on the transmitting side L f1 and the compensation capacitor of the transmitter-side parallel branch II C fp ;

[0108] Step 302: Calculate receiving compensation capacitance C s =1 / ( ωL s ) 2 .

[0109] The system parameters determined by the above transmission device and design method are shown in Table 1. The load current design value is 10A, the transmission power is 1kW, and the D y =100mm offset range, the output current change percentage is designed to be 10%. D z =The output current change percentage design value within the vertical distance range of 70-130mm is 15%.

[0110] Table 1 System parameters

[0111]

[0112] When the offset and vertical distance change, the coupling coil L p 、 L f and receiving coil L s Mutual Induction M ps and M fs The change curve is as follows Figure 4 As shown in the figure, it can be seen that with the increase of offset and vertical distance, the mutual inductance shows a downward trend, especially when the vertical distance increases, the mutual inductance decreases more. l Adjust the mutual inductance, and the equivalent mutual inductance value changes with offset and transmission distance as shown in the following curve: Figure 5 As shown. Figure 5 It can be seen that the equivalent mutual inductance increases slightly with the increase of the offset distance and decreases slightly with the increase of the vertical distance. The percentage change of mutual inductance is 9.8% and 14.3% respectively. It can be seen from formula (1.3) that when other parameters are determined, the load current and the system equivalent mutual inductance are in a simple linear relationship. Therefore, within the design offset and vertical distance variation range, the load current fluctuation is 9.8% and 14.3% respectively. Different from the general system, compared with the original mutual inductance value M fs and M ps , the equivalent mutual inductance value in the embodiment increases when the offset distance is large. Combining equations (1.7) and (1.9), it can be seen that the efficiency increases, which is conducive to efficient energy transmission.

[0113] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A wide-distance adaptive wireless power transmission device based on dual-coupling coils, characterized in that: The wireless power transmission device includes a transmitting side and a receiving side, and the transmitting side and the receiving side are arranged relative to each other to form a coupled induction; wherein the transmitting side includes a coupling coil L f , coupling coil L p , transmitting compensation coil L f1 , transmitter compensation capacitor C fp , DC power supply and inverter circuit; the receiving side includes a receiving coil L s , receiving compensation capacitor C s , rectifier filter circuit and equivalent load R L , the coupling coil L f The non-identical end and the coupling coil L p The transmitting compensation coil is connected to the same end of L f1 One end is connected to the output terminal A of the inverter circuit, and the other end is connected to the coupling coil L f The same-name terminal is connected; the transmitting compensation capacitor C fp One end is connected to the output terminal B of the inverter circuit, and the other end is connected to the coupling coil L f With coupling coil L p The common connection point is connected to the transmitting compensation coil L f1 and coupling coil L f Located on the transmitting side parallel branch I; the transmitting compensation capacitor C fp Located on the transmitting side parallel branch II; the coupling coil L p Located on the transmitting side parallel branch III; and the transmitting side parallel branch I is inductive; the transmitting side parallel branch III is inductive; the equivalent inductance of the transmitting side parallel branch I L fe Greater than the equivalent inductance of the transmitter-side parallel branch III L pe .

2. The wireless power transmission device according to claim 1, characterized in that: The coupling coil L f and coupling coil L p The coupling coil is coplanarly arranged on the planar magnetic core, and the coupling coil L f With receiving coil L s Mutual induction M fs The degree of change with offset distance ∂ M fs / ∂ y And the degree of change with transmission distance ∂ M fs / ∂ z Greater than the coupling coil L p With receiving coil L s Mutual induction M ps The degree of change with offset distance ∂ M ps / ∂ y And the degree of change with transmission distance ∂ M ps / ∂ z , that is, satisfying ∂ M fs / ∂ y >∂ M ps / ∂ y , ∂ M fs / ∂ z >∂ M ps / ∂ z .

3. The wireless power transmission device according to claim 1, characterized in that: The coupling coil L f The coupling coil is located inside the plane of the coupling mechanism on the transmitting side. L p Located outside the plane of the transmitting side coupling mechanism, and the coupling coil L f and coupling coil L p It adopts concentric ring structure.

4. The wireless power transmission device according to claim 1, characterized in that: The receiving coil L s , receiving compensation capacitor C s and system operating frequency ω satisfy ω =1 / ( L s C s ) 0.5 .

5. A parameter design method for a wireless power transmission device according to any one of claims 1 to 4, characterized in that: The parameter design method comprises: Step 1: setting circuit parameters of the wireless power transmission device, wherein the circuit parameters include all coupling relationship models included in the wireless power transmission device; Step 2: Setting coil parameters of the wireless power transmission device; Step 3: Setting topology compensation parameters for the wireless power transmission device.

6. The parameter design method according to claim 5, characterized in that: The circuit parameters of the wireless power transmission device are set in step 1, wherein the circuit parameters include all coupling relationship models included in the wireless power transmission device, including: Step 101: Establishing an equivalent circuit model of a wide-distance adaptive wireless power transmission system with dual coupled coils; Step 102: Calculate the relationship between each loop current and the coupling mechanism parameters. The relationship model is: in, M fs For coupling coil L f With receiving coil L s Mutual induction, M ps For coupling coil L p With receiving coil L s Mutual induction, M fp For coupling coil L f With coupling coil L p The mutual induction between α = - ( M fs + M ps ) 2 ω + ω 3 ( M ps 2 L fe + M fs 2 L pe ) C e , β = R EF ( L fe (-1+ ω 2 L pe C e )- L pe ), L fe = L f1 + L f + M fp , L pe = L p + M fp , ω is the system operating frequency, C e is the equivalent capacitance of the transmitting side parallel branch II, U s is the inverter output voltage, R EF Input equivalent AC resistance for the rectifier bridge; Step 103: Calculate Capacitance C e The relationship between the coupling mechanism parameters is as follows: Among them, the regulatory factor ; Step 104: Calculate the compensation coil of the transmitting-side parallel branch I L f1 The relationship between the coupling mechanism parameters is as follows: Step 105: Calculate the compensation capacitance of the transmitter-side parallel branch II C fp The relationship between the coupling mechanism parameters is as follows: Step 106: Calculate the load current I oN The relationship between the coupling mechanism parameters is as follows: in, U d is the DC input voltage of the inverter, M eq is the equivalent mutual inductance between the transmitting and receiving sides, defined as M eq = M fs - λM ps ; Step 107: Calculate System AC Efficiency η The relationship between the coupling mechanism parameters is as follows: in, R Lf 、 R Lp 、 R Ls For coupling coil L f , coupling coil L p , receiving coil L s The internal resistance of the coil; Step 108: Calculate the optimal AC resistance corresponding to the maximum system AC efficiency R EF_opt The relationship between the coupling mechanism parameters is as follows: Step 109: Calculate the system's maximum AC efficiency η max The relationship between the coupling mechanism parameters is as follows: Step 1010: Calculate rated output power P oN The relationship between the optimal AC internal resistance and the coupling mechanism parameters is as follows: Step 1011: Calculate the equivalent mutual inductance required to meet the rated output power and maximize efficiency.

7. The parameter design method according to claim 5, characterized in that: The step 2 of setting the coil parameters of the wireless power transmission device includes: Step 201: Determine the coupling coil L p and receiving coil L s Outer diameter R p 、 R s and number of turns N p 、 N s ; Step 202: Determine the coupling coil L f Minimum inner diameter r f ; Step 203: Calculate the coupling coil L f Maximum number of turns under the current inner diameter N max =( R p - N p * D _wire - r f ) / D _wire ,in, D _wire is the diameter of the Litz wire; Step 204: Coupling Coil L f Number of turns N f Calculate the offset distance starting from 2 and increasing to the maximum value under the current inner diameter D y and vertical change distance D z Under this condition, the mutual inductance change rate ∂ M fs / ∂ y , ∂ M ps / ∂ y , ∂ M fs / ∂ z , ∂ M ps / ∂ z ; Step 205: Enlarge the coupling coil L f Inner diameter r f , to determine whether the inequality is satisfied r f < R p - N p × D _wire If satisfied, add weight to calculate coupling coil L f Maximum number of turns under the current inner diameter N max =( R p - N p * D _wire - r f ) / D _wire , repeat step 204, if not satisfied, proceed to step 206; Step 206: Calculate the difference r f and N f Under the mutual induction when the offset and vertical distance change M fs and M ps The ratio of the rate of change is shown below: Step 207: Select λ , λ z < λ<λ y , and satisfies the formula and (1- δ ) I oN < I oN <(1+ δ ) I oN ,in, δ is the preset current change percentage.

8. The parameter design method according to claim 5, characterized in that: The step 3 of setting the topology compensation parameters for the wireless power transmission device includes: Step 301: Using the formula and , calculate the compensation coil of the parallel branch I on the transmitting side L f1 and the compensation capacitor of the transmitter-side parallel branch II C fp ; Step 302: Calculate receiving compensation capacitance C s =1 / ( ωL s ) 2 .

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