Capacitor configuration method based on interleaved winding coils and wireless power transmission system

Abstract

The present invention relates to the technical field of wireless power transmission (WPT), and in particular to a capacitor configuration method and a wireless power transmission system based on an interleaved winding coil. The method first winds the power transmission coil into an interleaved winding coil structure, and further, based on the interleaved coil winding structure, by analyzing the equivalent inductance characteristics of the coil, connects multiple compensation capacitors in series between the interleaved coil winding structure so that the potential between adjacent turns exhibits an anti-phase characteristic. The invention strategically allocates the positions of multiple compensation capacitors to maximize the offset of the voltage difference between adjacent turns, thereby effectively reducing the electric field exposure level. The arrangement of the compensation capacitors depends only on the structural characteristics and operating frequency of the coil, making it adaptable to various compensation network configurations, so that the wireless power transmission system can significantly reduce the electric field exposure level while maintaining high efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless power transmission (WPT), and in particular to a capacitor configuration method based on an interleaved winding coil and a wireless power transmission system. Background Art

[0002] Inductive Wireless Power Transfer (IPT) systems have significantly changed the way electric vehicles (EVs) are charged through efficient wireless power transmission. However, exposure to electric fields in IPT systems poses safety risks. High electric fields generated by electromagnetic radiation can adversely affect the environment, equipment, and human health. Especially during wireless charging, strong electric fields can cause electromagnetic interference (EMI) to nearby electronic devices, affecting their normal operation. Long-term exposure to high electric fields can also pose potential health risks, especially to sensitive areas such as the head and chest.

[0003] Although existing IPT designs incorporate electromagnetic shielding, uneven electric field distribution and incomplete shielding can still lead to safety issues. Therefore, reducing electric field strength and optimizing electric field distribution are crucial for ensuring the safe and reliable operation of wireless electric vehicle charging systems. Traditional average segmentation methods are limited in their effectiveness at reducing electric field strength because they fail to account for the phase characteristics of the interturn voltage, resulting in large areas of high electric field strength. Summary of the Invention

[0004] The present invention provides a capacitor configuration method based on interleaved winding coils and a wireless power transmission system, which solves the technical problem that the traditional resonant capacitor average segmentation method does not consider the phase characteristics of the inter-turn voltage, resulting in a large area of ​​high electric field strength.

[0005] To solve the above technical problems, the present invention provides a capacitor configuration method based on an interleaved winding coil, comprising the steps of:

[0006] The energy transmission coils of the wireless power transmission system are wound in an interlaced manner. n The staggered winding coil has the same direction of turns. Staggered winding means winding from outside to inside. n / 2 turns, in front n After winding from inside to outside between turns n / 2 turns;

[0007] The series compensation capacitor connected to the energy transmission coil is equivalent to m The compensation capacitors are distributed and connected in series in the interleaved winding coils, where the starting point of each turn of the interleaved winding coil is used as the node position for connecting a compensation capacitor in series.m The compensation capacitors are connected in series m The node position, the m The node positions satisfy m After the compensation capacitors are connected in series, the voltage difference between adjacent turns of the interleaved winding coil presents an anti-phase characteristic.

[0008] Furthermore, the voltage difference between adjacent turns of the interleaved winding coils exhibits an anti-phase characteristic, which means:

[0009] forward n The voltage at the starting point of a 2-turn interleaved winding coil and the average voltage at all starting points relative to ground V avg The imaginary part of the difference between n The voltage at the starting point of a 2-turn interleaved winding coil and the average voltage at all starting points relative to ground V avg The imaginary part of the difference between them is less than 0.

[0010] Further, m The compensation capacitors are connected in series m Node location, specifically including the steps:

[0011] S1. m The compensation capacitors are connected in series in the first group m Node locations;

[0012] S2. Based on the current structural characteristics, calculate n The voltage at the starting point of the interleaved winding coil V k The average voltage at all starting locations relative to ground V avg The difference between V k,diff , k Indicates the k Starting position, 1≤ k ≤ n ;

[0013] S3, according to the difference V k,diff Determine whether the voltage difference between adjacent turns of the staggered winding coils presents an anti-phase characteristic. If so, the current group m The node positions are used as the final m Node position, if not, go to the next step;

[0014] S4. m The compensation capacitors are connected in series in the second group m node position and returns to step S2.

[0015] Further, in step S3, if all groups are traversed m If the voltage difference between the adjacent turns of the staggered winding coils still does not show the anti-phase characteristic, then change m After taking the value of , return to step S1.

[0016] Further, the k The voltage at the starting point V k For: Slave node k To Node n Each equivalent inductor voltage between jωIL i The sum of the voltages of each capacitor between these nodes is subtracted from the sum of the voltages of each capacitor between these nodes. jIm k / ( ωC ), I It represents the RMS value of the current in the energy transmission coil. C Indicates the capacitance value of each compensation capacitor, ω represents the operating angular frequency of the system, m k Indicates that it is located at the node k and nodes n The number of capacitors between.

[0017] Further, the i Equivalent inductance of a coil with interleaved turns L i By its own self-inductance L ii The sum of the coupled inductances between the two turns and the other turns, each coupled inductance is composed of the coupling coefficient k ij The product of the two turns' self-inductance and the geometric mean is given by

[0018] Furthermore, the average voltage of all starting points relative to the ground is V avg The calculation method of the voltage offset caused by the compensation capacitor is to add up all the node voltages without compensation capacitors, subtract the voltage offset caused by the compensation capacitor, and then divide it by the total number of turns. m Add the node numbers where the compensation capacitors are located, and subtract the number of compensation capacitors m Add 1, and then multiply by the product of the current and the reactance of the compensation capacitor, where the node position of the first compensation capacitor is at the starting point of the first turn of the interleaved winding coil.

[0019] Furthermore, the energy transmission coil includes a transmitting coil and a receiving coil.

[0020] The present invention also provides a wireless power transmission system, the key of which is: comprising a power transmitting end and a power receiving end, the power transmitting end is provided with a connected transmitting end compensation network and a transmitting coil, the power receiving end is provided with a connected receiving coil and a receiving end compensation network, the transmitting coil and the receiving coil are interlaced and wound into n The staggered winding coil has the same direction of turns. Staggered winding means winding from outside to inside. n / 2 turns, in front n After winding from inside to outside between turns n / 2 turns;

[0021] The compensation capacitor connected to the transmitting coil in the transmitting-end compensation network and the compensation capacitor connected to the receiving coil in the receiving-end compensation network are configured according to the capacitor configuration method based on interleaved winding coils.

[0022] Preferably, the transmitter compensation network and the receiver compensation network adopt LCC compensation networks.

[0023] The present invention provides a capacitor configuration method and wireless power transmission system based on an interleaved winding coil. First, the energy transmission coil is wound into an interleaved winding coil structure. Further, based on the interleaved coil winding structure, by analyzing the equivalent inductance characteristics of the coil, multiple compensation capacitors are connected in series between the interleaved coil winding structure so that the potential between adjacent turns can present an anti-phase characteristic. The invention strategically allocates the positions of multiple compensation capacitors to maximize the offset of the voltage difference between adjacent turns, thereby effectively reducing the electric field exposure level. The arrangement of the compensation capacitors depends only on the structural characteristics and operating frequency of the coil, making it adaptable to various compensation network configurations, so that the wireless power transmission system can significantly reduce the electric field exposure level while maintaining high efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a flow chart of a capacitor configuration method based on an interleaved winding coil provided by an embodiment of the present invention;

[0025] Figure 2 Schematic diagram of the structure of a 6-turn staggered winding coil provided by an embodiment of the present invention;

[0026] Figure 3 The embodiment of the present invention provides m The compensation capacitors are connected in series m The equivalent circuit diagram after the node position;

[0027] Figure 4 is a coil node voltage distribution diagram provided by an embodiment of the present invention;

[0028] Figure 5is an example diagram of a circuit structure of a wireless power transmission system provided by an embodiment of the present invention;

[0029] Figure 6 1 is a diagram illustrating a configuration process of compensation capacitor positions in a wireless power transmission system according to an embodiment of the present invention;

[0030] Figure 7 is a top view of a simulated transmitting end or receiving end of a coupling mechanism provided by an embodiment of the present invention;

[0031] Figure 8 1 is a diagram of magnetic field and electric field distribution of three compensation schemes provided by embodiments of the present invention;

[0032] Figure 9 1 is a diagram of current and voltage waveforms during operation of a prototype device provided by an embodiment of the present invention;

[0033] Figure 10 This is a DC-DC efficiency curve diagram of three configurations at different output power levels provided by an embodiment of the present invention;

[0034] Figure 11 1 is an electric field strength test diagram of three configurations provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0035] The following describes the embodiments of the present invention in detail with reference to the accompanying drawings. The embodiments are provided for illustrative purposes only and are not to be construed as limiting the present invention. The accompanying drawings are provided for reference and illustration only and do not constitute a limitation on the scope of protection of the present invention. Many changes may be made to the present invention without departing from the spirit and scope of the present invention.

[0036] The embodiment of the present invention first provides a capacitor configuration method based on staggered winding coils, such as Figure 1 As shown in the flowchart, the steps include:

[0037] The energy transmission coils of the wireless power transmission system are wound in an interlaced manner. n The staggered winding coil has the same direction of turns. Staggered winding means winding from outside to inside. n / 2 turns, in front n After winding from inside to outside between turns n / 2 turns;

[0038] The series compensation capacitor connected to the energy transmission coil is equivalent to m The compensation capacitors are distributed and connected in series in the interleaved winding coils, where the starting point of each turn of the interleaved winding coil is used as the node position for connecting a compensation capacitor in series. m The compensation capacitors are connected in series m The node position, the m The node positions satisfy mAfter the compensation capacitors are connected in series, the voltage difference between adjacent turns of the interleaved winding coil presents an anti-phase characteristic.

[0039] The energy transmission coil here includes a transmitting coil and a receiving coil. The structure of a 6-turn interleaved winding coil is as follows Figure 2 As shown, it includes the first 3 turns wound from outside to inside L 11 、 L 22 and L 33 and the last 3 turns wound from inside to outside L 44 、 L 55 and L 66 To facilitate connection of the compensation capacitor, this embodiment adopts a winding method in which the starting and ending points of the coil are both located outside the coil (from outside to inside and then from inside to outside). In other embodiments, a winding method from inside to outside and then from outside to inside may also be adopted.

[0040] use C 1 to C m Respectively m The starting point of each turn of the interleaved winding coil is used as the node position for connecting a compensation capacitor in series. m The compensation capacitors are connected in series m The equivalent circuit diagram after the node positions are as follows Figure 3 shown. Figure 3 middle, L ii Indicates the i The self-inductance of the coil, M ij Indicates the i Turn coil and j Mutual inductance between coil turns ( i ≠ j ), I is the RMS value of the current flowing through the coil, V in-coil is the equivalent AC source of the energy transfer coil, V Li For the i The voltage across the coil, V i For the i The voltage at the starting point of the coil relative to the ground. Figure 3 The circuit structure relationship shown in the figure is i Equivalent inductance of a coil L i By its own self-inductance L iiThe sum of the coupled inductances between the two turns and the other turns, each coupled inductance is composed of the coupling coefficient k ij The product of the two turns' self-inductance and the geometric mean value is given by: L ii Indicates the i The self-inductance of the interleaved turns winding coil, k ij Indicates the i The turns of the interleaved winding coil are j The coupling coefficient between the turns of the staggered winding coil can be expressed as follows:

[0041] ,

[0042] Compensation capacitor C The total number is m ,use ω represents the operating angular frequency of the system, m k Indicates that it is located L k ( k =1,2,…, n )and L n The number of capacitors between them satisfies 0≤ m k ≤ m Ignoring the internal resistance of the inductor, after connecting the compensation capacitor, L k Voltage at the starting point V k For: Slave node k To Node n Each equivalent inductor voltage between ( jωIL i ) minus the sum of the voltages of each capacitor between these nodes ( jIm k / ( ωC )), which can be expressed as:

[0043] .

[0044] make S i ( i =1,2,.. m )express m The node position of the compensation capacitor is located. The first compensation capacitor is located at the input port of the staggered winding coil (the starting point of the first turn coil), that is, S 1=1. Average voltage of all starting points relative to ground V avgThe voltage offset is calculated by adding up the voltages of all nodes without compensation capacitors (only equivalent inductance per turn), subtracting the voltage offset caused by the compensation capacitor, and then dividing by the total number of turns. m The node number where the compensation capacitor is located S i ( i =2,.. m ) plus the amount of compensation capacitors m Add 1 and multiply by the product of the current and the reactance of the compensation capacitor, which can be expressed as:

[0045] .

[0046] Based on equations (2) and (3), the starting voltage of each turn of the interleaved winding coil can be obtained: V k With the average voltage V avg The difference is expressed as:

[0047] .

[0048] Based on the staggered winding structure design of the energy transfer coil, in order to offset the voltage between adjacent turns to the maximum extent, the voltage difference between adjacent turns should show an anti-phase characteristic, such as Figure 4 The coil node voltage distribution diagram is shown in the figure. Therefore, the voltage difference between the coil starting positions must meet the requirements of formula (5):

[0049] ,

[0050] Formula (5) means that n The voltage at the starting point of a 2-turn interleaved winding coil is equal to the average voltage at all starting points relative to ground. V avg The imaginary part of the difference Im( V k,diff ) is greater than 0; n The voltage at the starting point of a 2-turn interleaved winding coil and the average voltage at all starting points relative to ground V avg The imaginary part of the difference between V k,diff ) is less than 0.

[0051] According to equations (4) and (5), the positions of all compensation capacitors can be determined by equation (6):

[0052] ,

[0053] Among them, the parameters customized for simplified form AThe definition is as follows:

[0054] .

[0055] From equations (6) and (7), it can be seen that the location of the compensation capacitor depends only on the structural characteristics and operating frequency of the coil, and is independent of the current flowing through the coil or the terminal voltage of the coil. This shows that the capacitor configuration method based on interleaved winding coils proposed in this invention has strong adaptability and can be flexibly applied to various compensation topologies.

[0056] Will m The compensation capacitors are connected in series m Node location, specifically including the steps:

[0057] S1. m The compensation capacitors are connected in series in the first group m Node locations;

[0058] S2. Based on the current structural characteristics, calculate n The voltage at the starting point of the interleaved winding coil V k The average voltage at all starting locations relative to ground V avg The difference between V k,diff , k Indicates the k Starting position, 1≤ k ≤ n ;

[0059] S3, according to the difference V k,diff Determine whether the voltage difference between adjacent turns of the staggered winding coils presents an anti-phase characteristic. If so, the current group m The node positions are used as the final m Node position, if not, go to the next step;

[0060] S4. m The compensation capacitors are connected in series in the second group m node position and returns to step S2.

[0061] On the basis of the above-mentioned capacitor configuration method based on the staggered winding coil, an embodiment of the present invention further provides a wireless power transmission system, which includes a power transmitting end and a power receiving end, wherein the power transmitting end is provided with a connected transmitting end compensation network and a transmitting coil, and the power receiving end is provided with a connected receiving coil and a receiving end compensation network, and the transmitting coil and the receiving coil are staggered to form a n The staggered winding coil has the same direction of turns. Staggered winding means winding from outside to inside. n / 2 turns, in frontn After winding from inside to outside between turns n The compensation capacitor connected to the transmitting coil in the transmitting-end compensation network and the compensation capacitor connected to the receiving coil in the receiving-end compensation network are configured according to the above-mentioned capacitor configuration method based on the interleaved winding coil.

[0062] An example of a circuit structure of the wireless power transmission system proposed in this embodiment is as follows: Figure 5 As shown in the figure, the transmitter compensation network and the receiver compensation network of the wireless power transmission system adopt LCC compensation network. On the basis of the bilateral LCC compensation network, the series compensation capacitor of the transmitter compensation network is connected to the C p and the series compensation capacitor of the receiving end compensation network C s They are divided into four, the first one is fixedly connected to the starting position of the transmitting coil and the receiving coil, and the other three ( C px / C sx , x = 2, 3, 4) are integrated into the transmitting coil using a capacitor configuration method based on interleaved winding coils L p and receiving coil L s In a wireless power transmission system, the configuration process of the compensation capacitor position is as follows: Figure 6 As shown, the specific steps include:

[0063] 1. Determine the basic system parameters according to actual application requirements, including the system output power P out , operating frequency f sw , system input voltage V in , Transmitting coil size D p , receiving coil size D s , Number of transmitter compensation capacitors m p , Number of compensation capacitors at the receiving end m s ;

[0064] 2. Based on the size of the transmitting coil D p , receiving coil size D s Determine the number of turns of the transmitting coil n p , Number of turns of receiving coil n s, further determine the self-inductance of the transmitting coil L p , receiving coil self-inductance L s ;

[0065] 3. Based on operating frequency f sw , self-inductance of the transmitting coil L p , receiving coil self-inductance L s , according to the resonance relationship, determine the compensation capacitance and compensation inductance values;

[0066] 4. Establish a coil simulation model to determine the equivalent inductance of each turn of the transmitting coil and the receiving coil;

[0067] 5. Use iterative optimization to determine the final m p Node positions and m s Node locations.

[0068] In step 5, the iterative optimization method for the transmitting coil is the same as that for the receiving coil. Taking the transmitting coil as an example, the final m p The process of finding the node position is as follows:

[0069] Sure m p -1 node position for the first group and m p The transmitter compensation capacitors are connected in series;

[0070] Determine whether the voltage difference between adjacent turns of the transmitting coil presents an anti-phase characteristic. If so, m The node positions are used as the final m Node position, if not, go to the next step;

[0071] Will m The compensation capacitors are connected in series in the second group m node position and return to the previous step.

[0072] The output power of the system can be derived by the fundamental harmonic approximation (FHA) method as follows:

[0073] ,

[0074] in, k is the coupling coefficient between the transmitting coil and the receiving coil, U AB and U abis the voltage of the inverter and rectifier bridge arms, L f1 and L f2 They are the compensation inductors in the transmitter compensation network and the receiver compensation network respectively.

[0075] In summary, the capacitor configuration method based on the staggered winding coil and the wireless power transmission system provided by the embodiment of the present invention first wind the energy transmission coil into a staggered winding coil structure, and further based on the staggered coil winding structure, by analyzing the equivalent inductance characteristics of the coil, multiple compensation capacitors are connected in series between the staggered coil winding structure so that the potential between adjacent turns can present an inverted characteristic. The invention strategically allocates the positions of multiple compensation capacitors to maximize the offset of the voltage difference between adjacent turns, thereby effectively reducing the electric field exposure level. The arrangement of the compensation capacitors depends only on the structural characteristics and operating frequency of the coil, so that it can adapt to various compensation network configurations, so that the wireless power transmission system can significantly reduce the electric field exposure level while maintaining high efficiency.

[0076] The simulation and experimental verification are carried out below.

[0077] This embodiment uses the finite element simulation software HFSS to verify the effectiveness of the proposed method and system. The coil setting parameters are shown in Table 1:

[0078]

[0079] In the simulation setup, the switching frequency was set to 85 kHz. The transmitting and receiving coils had the same size and number of turns (22). Both the transmitting and receiving coils were equipped with shielding plates and magnetic cores. The coil currents on the transmitting and receiving sides were 11.5A and 13A, respectively. Based on the proposed compensation capacitor position design process, the compensation capacitor position was determined through iterative calculation. C p The corresponding four compensation capacitors C p1 -C p4 The best positions are 1, 9, 16 and 19, C s The corresponding four compensation capacitors C s1 -C s4 The best positions are 1, 9, 16 and 19 respectively.

[0080] Figure 7 The top view of the simulated coupling mechanism transmitting or receiving end is shown in Figure 2. Figure 7It can be seen that the 2nd, 3rd, and 4th compensation capacitors are connected in series at the 9th, 16th, and 19th turns, respectively. Under the same working conditions, the proposed compensation capacitor position (ITAP configuration) is compared with the average segmented configuration (located at 1, 7, 12, and 18, respectively) and the non-segmented configuration. The magnetic and electric field distributions of the three compensation schemes are shown in Figure 2. Figure 8 shown. Figure 8 The results show that the magnetic field distribution of the three compensation schemes is almost the same, indicating that the position of the compensation capacitor has no significant effect on the magnetic field distribution of the coupling mechanism and therefore has no significant effect on the transmission efficiency of the system. In terms of electric field distribution, the proposed ITAP configuration significantly reduces the high electric field intensity areas, and these areas are mainly concentrated near the coil.

[0081] In order to verify the advantage of the capacitor configuration method proposed in the embodiment of the present invention in reducing electric field exposure, a 3.3 kW prototype was built according to the above simulation settings. Figure 9 The current and voltage waveforms of the prototype are shown. I pri is the current of the transmitting coil, I AB is the inverter output current at the transmitter. Since the waveforms of the three compensation configurations are almost the same, only the experimental waveform of the ITAP configuration is shown. Figure 9 It can be seen that the system successfully achieves zero voltage switching (ZVS). Figure 10 The DC-DC efficiency curves for three configurations at different output power levels are shown. Figure 10 It can be seen that the proposed ITAP configuration does not affect the transmission efficiency of the system, which further verifies the accuracy of the simulation results.

[0082] The electric field strength of the three configurations was measured using the NF-5035 tester. The test results are as follows: Figure 11 As shown in the figure, the test position is based on the edge and middle height of the coupling mechanism as the starting point, and moves outward in the horizontal direction to perform the electric field strength test. Figure 11 It can be seen that the electric field strength of the ITAP configuration is 50.93% of that of the non-segmented configuration and 62.73% of that of the average segmented configuration, significantly reducing the external electric field exposure.

[0083] In summary, the present invention proposes a capacitor configuration method and a wireless power transmission system based on staggered winding coils, which aims to reduce the electric field radiation in the inductive power transmission system. The proposed capacitor configuration method and system strategically arrange individual compensation capacitors to generate an anti-phase voltage difference between adjacent coil turns, thereby maximally offsetting the inter-turn voltage and significantly reducing the internal and external electric field strength. Simulation and experimental results verify that the capacitor configuration method and system significantly reduce the electric field exposure level while maintaining the efficiency of wireless power transmission. Comparison with traditional average segmented and non-segmented compensation configurations shows that the capacitor configuration method and system proposed in the embodiment of the present invention have significant advantages in suppressing high electric field areas, thereby improving the safety of the wireless power transmission system.

[0084] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A capacitor configuration method based on interleaved winding coils, characterized in that: Including steps: The energy transmission coils of the wireless power transmission system are wound in an interlaced manner. n The staggered winding coil has the same direction of turns. Staggered winding means winding from outside to inside. n / 2 turns, in front n After winding from inside to outside between turns n / 2 turns; The series compensation capacitor connected to the energy transmission coil is equivalent to m The compensation capacitors are distributed and connected in series in the interleaved winding coils, where the starting point of each turn of the interleaved winding coil is used as the node position for connecting a compensation capacitor in series. m The compensation capacitors are connected in series m The node position, the m The node positions satisfy m After the compensation capacitors are connected in series, the voltage difference between the adjacent turns of the staggered winding coils presents an anti-phase characteristic: n The voltage at the starting point of a 2-turn interleaved winding coil and the average voltage at all starting points relative to ground V avg The imaginary part of the difference between n The voltage at the starting point of a 2-turn interleaved winding coil and the average voltage at all starting points relative to ground V avg The imaginary part of the difference between them is less than 0; Will m The compensation capacitors are connected in series m Node location, specifically including the steps: S1. m The compensation capacitors are connected in series in the first group m Node locations; S2. Based on the current structural characteristics, calculate n The voltage at the starting point of the interleaved winding coil V k The average voltage at all starting locations relative to ground V avg The difference between V k,diff , k Indicates the k Starting position, 1≤ k ≤ n ; S3, according to the difference V k,diff Determine whether the voltage difference between adjacent turns of the staggered winding coils presents an anti-phase characteristic. If so, the current group m The node positions are used as the final m Node position, if not, go to the next step; S4. m The compensation capacitors are connected in series in the second group m node position and returns to step S2.

2. The capacitor configuration method based on interleaved winding coils according to claim 1, characterized in that: In step S3, if all groups are traversed m If the voltage difference between the adjacent turns of the staggered winding coils still does not show the anti-phase characteristic, then change m After taking the value of , return to step S1.

3. The capacitor configuration method based on interleaved winding coils according to claim 2, characterized in that: No. k The voltage at the starting point V k For: Slave node k To Node n Each equivalent inductor voltage between jωIL i The sum of the voltages of each capacitor between these nodes is subtracted from the sum of the voltages of each capacitor between these nodes. jIm k / ( ωC ), I It represents the RMS value of the current in the energy transmission coil. C Indicates the capacitance value of each compensation capacitor, ω represents the operating angular frequency of the system, m k Indicates that it is located at the node k and nodes n The number of capacitors between them.

4. The capacitor configuration method based on interleaved winding coils according to claim 3, characterized in that: No. i Equivalent inductance of a coil with interleaved turns L i By its own self-inductance L ii The sum of the coupled inductances between the two turns and the other turns, each coupled inductance is composed of the coupling coefficient k ij The product of the two turns' self-inductance and the geometric mean is given by 5. The capacitor configuration method based on interleaved winding coils according to claim 4, characterized in that: The average voltage at all starting locations relative to ground V avg The calculation method of the voltage offset caused by the compensation capacitor is to add up all the node voltages without compensation capacitors, subtract the voltage offset caused by the compensation capacitor, and then divide it by the total number of turns. m Add the node numbers where the compensation capacitors are located, and subtract the number of compensation capacitors m Add 1, and then multiply by the product of the current and the reactance of the compensation capacitor. The node position of the first compensation capacitor is at the starting point of the first turn of the interleaved winding coil.

6. The capacitor configuration method based on interleaved winding coils according to any one of claims 1 to 5, characterized in that: The energy transmission coil includes a transmitting coil and a receiving coil.

7. A wireless power transmission system, characterized in that: It includes an electric energy transmitting end and an electric energy receiving end, wherein the electric energy transmitting end is provided with a connected transmitting end compensation network and a transmitting coil, and the electric energy receiving end is provided with a connected receiving coil and a receiving end compensation network, wherein the transmitting coil and the receiving coil are wound alternately. n The staggered winding coil has the same direction of turns. Staggered winding means winding from outside to inside. n / 2 turns, in front n After winding from inside to outside between turns n / 2 turns; The compensation capacitor connected to the transmitting coil in the transmitting-end compensation network and the compensation capacitor connected to the receiving coil in the receiving-end compensation network are configured according to the capacitance configuration method based on interleaved winding coils according to any one of claims 1 to 6.

8. The wireless power transmission system according to claim 7, wherein: The transmitting end compensation network and the receiving end compensation network adopt LCC compensation networks.

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