Wireless power transmission device and parameter setting method

Abstract

The present invention provides a wireless power transmission device and parameter setting method. 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. The parameter setting method includes calculating the relationship models and equivalent mutual inductance values of each wireless power transmission device to obtain the relationship models and equivalent mutual inductance values of all coupling relationships of the wireless power transmission device; calculating the coil parameters of the wireless power transmission device; and calculating the topology compensation parameters of the wireless power transmission device.

Description

Technical Field

[0001] The invention provides a wireless power transmission device and a parameter setting method, belonging to the technical field of wireless power transmission. Background Art

[0002] Wireless power transmission technology eliminates the need for physical wire connections and utilizes electromagnetic induction to wirelessly transfer energy from the transmitter to the receiver. Due to the flexibility of the relative positions of the transmitter and receiver, the transceiver coils are prone to offset, a characteristic of wireless power transmission systems. Furthermore, the transmission distance between the transceiver coils varies depending on the receiving end. Changes in offset and transmission distance can cause fluctuations in mutual inductance, leading to unstable system output and changes in transmission efficiency. To ensure stable system operation and efficient energy transmission, a wireless power transmission device and parameter design method with both strong omnidirectional offset and vertical distance adaptability are urgently needed to achieve efficient and stable energy output despite changes in offset and transmission distance. Summary of the Invention

[0003] The purpose of the present invention is to solve the problems of unstable system output and reduced efficiency caused by changes in offset and vertical distance in existing wireless power transmission systems. A dual-coupled wireless power transmission device and parameter design method with both strong omnidirectional offset and wide transmission distance adaptability is proposed. Without the need for a control circuit, the coil structure, compensation topology and parameter design of the wireless power transmission device enable the system to have a constant output capability when the offset and transmission distance change, thereby achieving stable energy transmission over a wide distance range. The technical solutions adopted are as follows:

[0004] A wireless power transmission device, comprising a transmitting side and a receiving side, wherein the transmitting side and the receiving side are arranged relative to each other to form a coupled induction; wherein the transmitting side comprises a coupling coil group, a DC power supply and an inverter circuit; and the receiving side comprises a receiving coil. L s , receiving compensation capacitor C s , rectifier filter circuit and equivalent load R L .

[0005] Furthermore, the coupling coil group includes a coupling coil L f , coupling coil L p , transmitter compensation capacitor C f and transmitter compensation capacitors C fp The coupling coil L f and coupling coil Lp Coplanar settings.

[0006] Furthermore, the coupling coil L f Located on the inner side of the coupling mechanism corresponding to the transmitting side, the coupling coil L p Located outside the coupling mechanism corresponding to the transmitting side, and the coupling coil L f The same-name end and the coupling coil L p The same-name ends are connected.

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

[0008] Furthermore, the receiving coil L s , receiving compensation capacitor C s and system operating frequency oh satisfy oh =1 / ( L s C s ) 0.5 .

[0009] Furthermore, the coupling coil L f With receiving coil Ls 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 Larger 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 .

[0010] A parameter design method for a wireless power transmission device, the parameter design method comprising:

[0011] Step 1: Calculate the relationship models and equivalent mutual inductance values of the wireless power transmission device to obtain the relationship models and equivalent mutual inductance values of all coupling relationships of the wireless power transmission device;

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

[0013] Step 3: Calculate the topology compensation parameters of the wireless power transmission device.

[0014] Furthermore, the step 1 of calculating the relationship models and equivalent mutual inductance values of the wireless power transmission device to obtain the relationship models and equivalent mutual inductance values of all coupling relationships of the wireless power transmission device includes:

[0015] Step 101: Establish an equivalent circuit model of a dual-coupled wireless power transmission system with both omnidirectional strong deviation and wide transmission distance adaptability;

[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 f - M fp -1 / ( oh 2 C f ), 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 capacitance of the transmitting-side parallel branch I C f The relationship between the coupling mechanism parameters, the relationship model is

[0023]

[0024] Step 105: Calculate the compensation capacitance of the transmitting-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 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 ;

[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 AC efficiency of the system R EF_opt The relationship between the coupling mechanism parameters is as follows:

[0033]

[0034] Step 109: Calculate the maximum AC efficiency of the system 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 calculation of the coil parameters of the wireless power transmission device in step 2 includes:

[0041] 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 ;

[0042] Step 202: Determine the coupling coilL 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 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 2.4, if not satisfied, go 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 calculation of the topology compensation parameters of the wireless power transmission device in step 3 includes:

[0050] Step 301: Using the formula and , calculate the compensation capacitance C of the parallel branch I on the transmitting side f 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 dual-coupled wireless power transmission device and parameter design method with both omnidirectional strong offset and wide transmission distance adaptability. This device is designed based on the fact that the actual system's transceiver side is prone to offset and the vertical distance is not fixed. The device's parameters are designed based on actual needs, resulting in high practicality. Furthermore, the introduction of the adjustment factor λ significantly increases the design freedom of the system's 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 systems with two anti-series coils on the transmitting side, the coupling coils Lf and Lp of the present invention are located on different branches, increasing the flexibility of system parameter design. Furthermore, the equivalent mutual inductance between the transceiver coils of the present invention can be flexibly designed based on actual operating conditions, and the equivalent mutual inductance can be greater than the mutual inductance between any two coils, achieving stable output characteristics while improving the system's transmission efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 This is a circuit schematic diagram of a dual-coupling wireless power transmission device with both omnidirectional strong deviation and wide transmission distance adaptability 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 dual-coupled wireless power transmission device with both omnidirectional strong offset and wide transmission distance adaptability;

[0057] Figure 4 Curves showing how the mutual inductance of the transceiver coils changes with offset and vertical distance, provided for the present invention; (a) curve showing how the mutual inductance changes with offset distance Dy; (b) 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; (a) curve showing how the mutual inductance changes with offset distance Dy; and (b) 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] The present invention provides a dual-coupling wireless power transmission device with both omnidirectional strong deviation and wide transmission distance adaptability, such as Figure 1 to Figure 2As shown, it includes a transmitting side and a receiving side; the transmitting side includes a coupling coil L f , coupling coil L p , transmitter compensation capacitor C f , transmitter compensation capacitor C fp , DC power supply, inverter circuit; the receiving side includes a receiving coil L s , receiving compensation capacitor C s , rectifier filter circuit, equivalent load R L ; Wherein, the coupling coil L f , coupling coil L p , receiving coil L s All 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 same-name end and the coupling coil L p The same-name terminal is connected; the transmitting compensation capacitor C f One end is connected to the inverter output terminal A, and the other end is connected to the coupling coil L f The non-identical end is connected; the transmitting compensation capacitor C fp One end is connected to the inverter output terminal B, and the other end is connected to the coupling coil L f With coupling coil L p The common connection point is connected; the transmitting compensation capacitor C f and coupling coil Lf 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;

[0063] Furthermore, the receiving coil L s , receiving compensation capacitor C s , system operating frequency oh satisfy oh =1 / ( L s C s ) 0.5 The transmitting side parallel branch I is capacitive; the transmitting side parallel branch III is inductive;

[0064] 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 Larger 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 ; The equivalent capacitance of the transmitting side parallel branch I is greater than the equivalent inductance of the transmitting side parallel branch III.

[0065] The dual-coupled wireless power transmission device described in this embodiment, which has both strong omnidirectional offset and wide transmission distance adaptability, improves the system's offset resistance and adaptability to vertical distance changes compared to the anti-offset 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.

[0066] Example 2

[0067] A parameter design method for a wireless power transmission device, the parameter design method comprising:

[0068] Step 1: Calculate the relationship models and equivalent mutual inductance values of the wireless power transmission device to obtain the relationship models and equivalent mutual inductance values of all coupling relationships of the wireless power transmission device;

[0069] Step 2: Calculate the coil parameters of the wireless power transmission device;

[0070] Step 3: Calculate the topology compensation parameters of the wireless power transmission device.

[0071] The step 1 of calculating the relationship models and equivalent mutual inductance values of the wireless power transmission device to obtain the relationship models and equivalent mutual inductance values of all coupling relationships of the wireless power transmission device includes:

[0072] Step 101: Establishing an equivalent circuit model of a dual-coupled wireless power transmission system with both omnidirectional strong deviation and wide transmission distance adaptability;

[0073] 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:

[0074] (1.1)

[0075] 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 f - M fp -1 / ( oh 2 C f ), 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;

[0076] Step 103: Calculate Capacitance C e The relationship between the coupling mechanism parameters is as follows:

[0077] (1.2)

[0078] in, , defined as the regulating factor and l<-1;

[0079] 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:

[0080] (1.3)

[0081] Step 105: Calculate the compensation capacitance of the transmitting-side parallel branch I according to the adjustment factor C f The relationship between the coupling mechanism parameters, the relationship model is

[0082] (1.4)

[0083] Step 106: Mutual Inductance M fp The equivalent inductance 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 The relationship between the coupling mechanism parameters is as follows:

[0084] (1.5)

[0085] Step 107: Calculate the load current based on the fundamental wave equivalent principle I oN The relationship between the coupling mechanism parameters is as follows:

[0086] (1.6)

[0087] 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 ;

[0088] Step 108: Calculate System AC Efficiency or The relationship between the coupling mechanism parameters is as follows:

[0089] (1.7)

[0090] in, R Lf 、 RLp 、 R Ls For coupling coil L f , coupling coil L p , receiving coil L s The internal resistance of the coil;

[0091] Step 109: From equation (1.7), we can get the optimal AC internal resistance when the system AC efficiency is the maximum.

[0092] (1.8)

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

[0094] (1.9)

[0095] Step 1011: Calculate rated output power P oN The relationship between the optimal AC internal resistance and the coupling mechanism parameters is as follows:

[0096] (1.10)

[0097] Step 1012: To maximize the system AC efficiency at rated power, the equivalent mutual inductance must satisfy

[0098] (1.11)

[0099] Specifically, the calculation of the coil parameters of the wireless power transmission device described in step 2 includes:

[0100] 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 ;

[0101] Step 202: Determine the coupling coil L f Minimum inner diameter r f ;

[0102] Step 203: Calculate the coupling coilL 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;

[0103] 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 ;

[0104] 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 2.4, if not satisfied, go to step 206;

[0105] 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)

[0106] Step 207: Optimization l ( l z < λ<λ y ), satisfying formula (1.11) and (1- d ) I oN < I oN <(1+ d ) I oN ,in, d is the preset current change percentage.

[0107] Specifically, the calculation of the topology compensation parameters of the wireless power transmission device in step 3 includes:

[0108] Step 301: Calculate the compensation capacitance of the transmitter-side parallel branch I using formulas (1.4) and (1.5). C f and the compensation capacitor of the transmitter-side parallel branch II C fp ;

[0109] Step 302: Calculate receiving compensation capacitance C s =1 / ( ωL s ) 2 .

[0110] The parameter design method of a dual-coupled wireless power transmission device with both omnidirectional strong offset and wide transmission distance adaptability described in this embodiment increases the flexibility of system design by introducing adjustment factors, improves the equivalent mutual inductance of the coupling mechanism, and realizes efficient and stable power transmission.

[0111] 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 Dy =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%.

[0112] Table 1 System parameters

[0113]

[0114] 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.

[0115] 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 wireless power transmission device, 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 group, a DC power supply and an 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 group includes a coupling coil L f , coupling coil L p , transmitter compensation capacitor C f and transmitter compensation capacitors C fp The coupling coil L f and coupling coil L p Coplanar arrangement, the coupling coil L f Located on the inner side of the coupling mechanism corresponding to the transmitting side, the coupling coil L p Located outside the coupling mechanism corresponding to the transmitting side, and the coupling coil L f The same-name end and the coupling coil L p The same-name terminal is connected to the transmitter compensation capacitor C f One end is connected to the output terminal A of the inverter circuit, and the transmitting compensation capacitor C f The other end of the coupling coil L f The non-identical end is connected; the transmitting compensation capacitor C fp One end is connected to the inverter circuit output terminal B, the transmitting compensation capacitor C fp The other end of the coupling coil L f With coupling coil L p wherein the transmitting compensation capacitor C f 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.

2. 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 .

3. The wireless power transmission device according to claim 2, characterized in that: 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 Larger 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 .

4. A parameter design method for a wireless power transmission device according to any one of claims 1 to 3, characterized in that: The parameter design method comprises: Step 1: Calculate the relationship models and equivalent mutual inductance values of the wireless power transmission device to obtain the relationship models and equivalent mutual inductance values of all coupling relationships of the wireless power transmission device; Step 2: Calculate the coil parameters of the wireless power transmission device; Step 3: Calculate the topology compensation parameters of the wireless power transmission device.

5. The parameter design method according to claim 4, characterized in that: The step 1 of calculating the relationship models and equivalent mutual inductance values of the wireless power transmission device to obtain the relationship models and equivalent mutual inductance values of all coupling relationships of the wireless power transmission device includes: Step 101: Establish an equivalent circuit model of a dual-coupled wireless power transmission system with both omnidirectional strong deviation and wide transmission distance adaptability; 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 f - M fp -1 / ( ω 2 C f ), 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 capacitance of the transmitting-side parallel branch I C f The relationship between the coupling mechanism parameters, the relationship model is Step 105: Calculate the compensation capacitance of the transmitting-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 AC efficiency of the system R EF_opt The relationship between the coupling mechanism parameters is as follows: Step 109: Calculate the maximum AC efficiency of the system 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.

6. The parameter design method according to claim 5, characterized in that: The calculation of the coil parameters of the wireless power transmission device described in step 2 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 2.4, if not satisfied, go 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.

7. The parameter design method according to claim 6, characterized in that: The calculation of the topology compensation parameters of the wireless power transmission device in step 3 includes: Step 301: Using the formula and , calculate the compensation capacitance C of the parallel branch I on the transmitting side f 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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