A coil arrangement design method and system of a multi-relay wireless energy transmission structure

Abstract

The present application relates to the technical field of wireless power transmission, and particularly relates to a coil arrangement design method and system of a multi-relay wireless power transmission structure, steps as follows: determining the transmission distance according to the voltage level; under the constraint of the transmission distance, introducing the arrangement ratio to represent the ratio of the second interval between adjacent groups in the non-equidistant grouping arrangement and the first interval between the coils in the same group, and establishing a geometric parameterized model of the non-equidistant arrangement; constructing the coupling impedance matrix based on the mutual inductance theory, and deducing the system energy transmission efficiency model; for different candidate values of the coil series, on the basis of the given coil parameters, the efficiency distribution curve of the system efficiency changing with the arrangement ratio is obtained by adjusting the arrangement ratio; based on the efficiency distribution curve, the optimal coil series and the corresponding optimal arrangement ratio that make the system energy transmission efficiency optimal are determined, and the optimal design scheme of the coil arrangement design is obtained. The present application can effectively improve the stability of system operation, the reliability of coil interface combination and the overall insulation stability.

Description

Technical Field

[0001] This invention relates to the field of wireless power transmission technology, and more specifically, to a coil arrangement design method and system for a multi-relay wireless power transmission structure. Background Technology

[0002] With the development of wireless power transmission technology, multi-relay magnetic coupling wireless power transmission schemes have gradually become an important technical route in long-distance wireless power transmission systems because they can effectively extend the transmission distance and improve the problem of limited single-stage power transmission distance. This type of technology usually arranges multiple relay coils between the transmitter and receiver, and transmits energy step by step through multiple resonant coupling units, thereby achieving stable power supply over long distances. Compared with the traditional single-transmitter, single-receiver wireless power transmission method, the multi-relay structure has obvious advantages in applications such as long-distance power transmission, power supply in space-constrained areas, and power supply across insulation gaps.

[0003] However, in practical applications, multi-relay wireless power transfer structures not only face the challenge of power transfer efficiency but also need to simultaneously meet requirements such as structural stability, insulation reliability, environmental tolerance, and long-term operational consistency. Especially in outdoor, humid, vibrating, temperature-varying, or long-term energized environments, the relative positions of the coils, the bonding state of the coil encapsulation interface, and the long-term stability of the overall insulation structure directly affect the transmission performance and operational reliability of the wireless power transfer system. For repeater power transfer structures with multiple stages and long transmission distances, an unreasonable coil arrangement can easily lead to significant cross-stage coupling, resulting in increased reactive power, increased voltage and current stress on devices, and decreased overall efficiency. Conversely, an unreasonable coil encapsulation method can easily lead to problems such as poor adhesion between the coil surface and the outer insulation material, localized gaps, interface cracking, or delamination failure after long-term operation.

[0004] In existing multi-relay wireless power transfer structures, common solutions typically employ multiple coils arranged at equal intervals along the power transfer direction, followed by complete overall insulation encapsulation after winding. While this approach is structurally simple, it often struggles to simultaneously address the requirements of electromagnetic coupling optimization and improved encapsulation interface reliability in long-distance, multi-level relay applications. Therefore, for long-distance multi-relay wireless power transfer systems, there is an urgent need for a technical solution that can reduce cross-level coupling, improve power transfer efficiency and system stability through optimized arrangement, while simultaneously enhancing coil interface reliability and overall insulation stability through hierarchical encapsulation, to meet the application requirements for long-term stable operation in complex environments. Summary of the Invention

[0005] The purpose of this invention is to provide a coil arrangement design method and system for a multi-relay wireless power transmission structure to solve the technical problems pointed out in the background art.

[0006] This invention is achieved through the following technical solution: a coil arrangement design method for a multi-relay wireless power transmission structure, applicable to multi-relay wireless power transmission systems with non-equal spacing grouping, comprising the following steps:

[0007] Determine the total transmission distance based on the voltage level of the target power supply scenario. ;

[0008] In the total transmission distance Under the constraint of arrangement ratio, This represents the second spacing between adjacent groups in a non-equal spacing arrangement. The first gap between the coils in the same group The ratio, and based on the number of coil stages Compared with the arrangement ratio Establish a geometric parameterized model of non-equidistant arrangement;

[0009] Based on mutual inductance theory, a coupling impedance matrix incorporating adjacent-level coupling and non-adjacent-level cross-level coupling is constructed using the aforementioned geometric parameterization model. And based on the coupling impedance matrix Derive the system energy transfer efficiency model;

[0010] For the number of coil stages at the aforementioned voltage level Different candidate values ​​are obtained by adjusting the arrangement ratio within a preset range based on the given coil parameters. The value is used to obtain the system efficiency as a function of the arrangement ratio. The changing efficiency distribution curve;

[0011] Based on the efficiency distribution curve, the optimal number of coil stages that maximizes the system's energy transfer efficiency is determined. and the corresponding optimal arrangement ratio The optimal design scheme for coil arrangement is obtained.

[0012] According to a preferred embodiment, the total transmission distance The constraint expression is as follows:

[0013]

[0014] In the above formula, Indicates the first The coil and the first The spacing between the coils, , Indicates the first The center position of each coil.

[0015] According to a preferred embodiment, in the geometric parameterization model, each stage of the coil is spaced at a first interval along the energy transmission direction. Second spacing Alternating arrangement, and ,when When it is an odd number, Indicates the first spacing ,when When it is even, Indicates the second spacing .

[0016] According to a preferred embodiment, the first spacing With the second spacing They are represented as follows:

[0017]

[0018]

[0019] In the above formula, Indicates the first spacing Quantity, Indicates the second spacing Quantity, , .

[0020] According to a preferred embodiment, the energy transfer efficiency model is expressed as:

[0021]

[0022] In the above formula, Indicates based on the arrangement ratio The system's energy transfer efficiency, Indicates the flow through the first The current in each coil, This indicates the load resistance on the receiving coil. This represents the input voltage of the transmitting coil. It represents the conjugate complex number of the transmitting coil current.

[0023] According to a preferred embodiment, the current flowing through the coil is calculated by the following equation:

[0024]

[0025] The coupling impedance matrix for The expression for the fully coupled impedance matrix is ​​as follows:

[0026]

[0027]

[0028]

[0029] In the above formula, This represents the self-impedance of the first coil. This represents the coupling impedance between the first and second coils, where... The imaginary unit, Indicates the operating angular frequency. This indicates the mutual inductance between the first and second coils.

[0030] The present invention also provides a multi-relay wireless power transmission system with non-equidistant grouping, including One coil;

[0031] The coil described includes one transmitting coil arranged in sequence. A relay coil and a receiving coil are placed coaxially. The coils are spaced at a first interval along the energy transmission direction. Second spacing Alternate arrangement.

[0032] According to a preferred embodiment, the second spacing Greater than the first spacing .

[0033] According to a preferred embodiment, the coils in the same group are integrated into an insulating package.

[0034] According to a preferred embodiment, when the voltage level of the target power supply scenario is 35kV, the load resistance is 10Ω, the coil self-inductance is 100uH, the coil internal resistance is 0.15Ω, the coil resonant matching capacitor is 11nF, and the coil outer diameter is 160mm, the number of turns of the coil is 6, and the arrangement ratio is... It is 1.2~1.3.

[0035] The coil arrangement design method and system of the multi-relay wireless power transmission structure provided by this invention have at least the following advantages and beneficial effects: This invention adopts an alternating arrangement structure with near and far spacing, reducing the reactive power of the system, thereby reducing the current and voltage on electronic components, preventing overvoltage damage to electronic components during operation, and reducing heat generation during operation, thus effectively improving the stability of system operation; This invention improves the reliability of coil interface bonding and overall insulation stability through a hierarchical packaging method; This invention does not require refined modification of the coils or complex control of the control circuit, achieving optimal system efficiency with minimal engineering effort, significantly reducing workload. Attached Figure Description

[0036] Figure 1This is a schematic diagram of the structure of the multi-relay wireless power transmission system provided in Embodiment 1 of the present invention;

[0037] Figure 2 This is a flowchart illustrating the coil arrangement design method provided in Embodiment 1 of the present invention;

[0038] Figure 3 The efficiency distribution curve of the 6-level wireless power transfer system provided in Embodiment 1 of the present invention;

[0039] Figure 4 Efficiency distribution curve of the 7-level wireless power transfer system provided in Embodiment 1 of the present invention;

[0040] Reference numerals: 1-transmitting coil, 2-relay coil, 3-receiving coil, 4-first gap, 5-second gap. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0042] Example 1

[0043] Figure 1 The diagram shows a multi-relay wireless power transfer system with non-equidistant groupings. This multi-relay wireless power transfer system includes... One coil; The coil described includes one transmitting coil arranged in sequence. A relay coil and a receiving coil are placed coaxially. The coils are spaced at a first interval along the energy transmission direction. Second spacing Alternating arrangement, with coils in the same group integrated into an insulated package. For example... Figure 1 As shown, and As a group, and and The two groups are arranged in the same pattern, and the arrangement pattern is used to form a long-distance multi-relay wireless power transmission string.

[0044] for Figure 1 The multi-relay wireless power transmission system shown in the figure has a non-equal spacing group arrangement. This invention provides a coil arrangement design method for the multi-relay wireless power transmission structure, which involves adjusting the coil arrangement of the first spacing... Second spacing The arrangement ratio and number of coils are optimized to achieve the optimal energy transmission efficiency of the multi-relay wireless power transfer system while satisfying the total transmission distance constraint. Specifically, this design method includes the following steps:

[0045] Step S1: Determine the total transmission distance based on the voltage level of the target power supply scenario. Taking a 35kV transmission line as an example, according to existing data, the insulation distance from the 35kV transmission line to the tower needs to be greater than 0.47 meters. Therefore, the total transmission distance can be... It is set at 0.5 meters.

[0046] Step S2, at the total transmission distance Under the constraint of arrangement ratio, This represents the second spacing between adjacent groups in a non-equal spacing arrangement. The first gap between the coils in the same group The ratio of .

[0047] Wherein, the total transmission distance The constraint expression is as follows:

[0048]

[0049] In the above formula, Indicates the first The coil and the first The spacing between the coils, , Indicates the first The center position of each coil.

[0050] Furthermore, based on the number of coil stages Compared with the arrangement ratio Establish a geometrically parametric model of non-equidistant arrangement, where the arrangement ratio... The expression is In some embodiments, in the geometric parameterization model, each stage of the coil is spaced at a first interval along the energy transmission direction. Second spacing Alternating arrangement, and That is, the coils at each level are arranged at equal intervals to avoid collisions; among them, when When it is an odd number, Indicates the first spacing ,when When it is even, Indicates the second spacing .

[0051] The first spacing With the second spacing They are represented as follows:

[0052]

[0053]

[0054] In the above formula, Indicates the first spacing Quantity, Indicates the second spacing Quantity, .

[0055] Step S3: Based on mutual inductance theory, construct a coupling impedance matrix that includes adjacent-level coupling and non-adjacent-level cross-level coupling using the geometric parameterization model. And based on the coupling impedance matrix A model for the system's energy transfer efficiency is derived.

[0056] In this embodiment, the energy transfer efficiency model is expressed as:

[0057]

[0058] In the above formula, Indicates based on the arrangement ratio The system's energy transfer efficiency, Indicates the flow through the first The current in each coil, This indicates the load resistance on the receiving coil. This represents the input voltage of the transmitting coil. It represents the conjugate complex number of the transmitting coil current.

[0059] The current flowing through the coil is calculated using the following equation:

[0060]

[0061] The coupling impedance matrix for The expression for the fully coupled impedance matrix is ​​as follows:

[0062]

[0063]

[0064]

[0065] In the above formula, This represents the self-impedance of the first coil. This represents the coupling impedance between the first and second coils, where... The imaginary unit, Indicates the operating angular frequency. This indicates the mutual inductance between the first and second coils.

[0066] Step S4: For the number of coil stages at the voltage level Different candidate values ​​are obtained by adjusting the arrangement ratio within a preset range based on the given coil parameters. The value is used to obtain the system efficiency as a function of the arrangement ratio. The efficiency distribution curve is changing.

[0067] Figure 3 The efficiency distribution of a wireless power transfer system with 6 turns of coil is shown in the results. It can be seen that in this 6-level wireless power transfer system, after adopting a non-equidistant arrangement of near-far-near-far, the system transmission efficiency increases with the arrangement ratio. The change exhibits a clear unimodal characteristic, that is, as the arrangement ratio increases... As the number of cells increases, the transmission efficiency increases rapidly before gradually decreasing, and then decreases again as the array ratio increases. It reaches its maximum value around 1.2 to 1.3, with a peak efficiency of approximately 86% to 87%.

[0068] Figure 4 The efficiency distribution of a wireless power transfer system with 7 turns of coil is shown in the results. It can be seen that in this 7-level wireless power transfer system, after adopting a near-far-near-far non-equidistant arrangement, the system efficiency increases with the arrangement ratio. The changes showed a clear trend of first rising and then falling, and in the arrangement ratio It reaches its highest value when it is around 0.9~1, with a peak efficiency of about 87%.

[0069] Step S5: Determine the optimal number of coil stages that maximizes the system's energy transfer efficiency based on the efficiency distribution curve. and the corresponding optimal arrangement ratio The optimal design scheme for coil arrangement is obtained.

[0070] In this embodiment, from Figure 3 As shown in the efficiency distribution curve, for a Level 6 wireless power transfer system, the efficiency distribution curve shows that, over a total transmission distance of [missing information - likely a distance], ... Under fixed conditions, appropriately increasing the spacing difference between adjacent coils can effectively reconstruct the coupling distribution of the system, creating a better combination between adjacent-stage coupling and cross-stage coupling. This improves the relay chain current distribution, reduces internal losses, and increases end-to-end transmission efficiency. Simultaneously, the curves also show that non-equidistant spacing is not necessarily better the larger the spacing difference. When the spacing ratio is... As the distance between near and far points increases further, system efficiency decreases, indicating that an excessively large difference in spacing can cause weakly coupled sections to become transmission bottlenecks, weakening the continuous energy transmission capability of the entire link. Therefore, a near-far-near-far arrangement has a clear efficiency-improving effect, but its effectiveness depends on a reasonable arrangement ratio. .

[0071] from Figure 4 As shown in the efficiency distribution curve, for a Level 7 wireless power transfer system, the efficiency distribution curve is relatively high over a certain total transmission distance. Under fixed conditions, appropriately introducing non-uniform spacing can also optimize system coupling and improve energy transmission in multi-level links, thereby increasing overall efficiency. Compared with a 6-level wireless power transfer system, the optimal spacing ratio of a 7-level wireless power transfer system is closer to 1, indicating that as the number of coil levels increases, the system's sensitivity to spacing non-uniformity further increases. Excessive differences in distance between near and far points are more likely to cause local weak coupling segments to become transmission bottlenecks, leading to a decrease in efficiency. Therefore, although the 7-level wireless power transfer system still has an optimal non-uniform spacing arrangement, the optimal point is more inclined towards a weak non-uniform distribution. That is, only a small adjustment in the distance between near and far points is needed to obtain a better efficiency improvement. This further illustrates that this type of arrangement has universality, but the optimal spacing parameters are not the same for different levels and need to be calculated and determined in conjunction with the specific number of levels.

[0072] The above two sets of calculation results show that, when designing a 35kV transmission line to tower wireless power transmission system, with a load resistance of 10Ω, a coil self-inductance of 100uH, a coil internal resistance of 0.15Ω, a coil resonant matching capacitor of 11nF, and a coil outer diameter of 160mm, if the coil has 6 turns and the arrangement ratio is... If the value is controlled between 1.2 and 1.3, the system can achieve optimal energy transmission efficiency.

[0073] In summary, this invention employs an alternating arrangement structure with varying distances, reducing the system's reactive power and thus lowering the current and voltage on electronic components. This prevents overvoltage damage to electronic components during operation and reduces heat generation, effectively improving system stability. Furthermore, the hierarchical packaging method enhances the reliability of coil interface bonding and overall insulation stability. This invention eliminates the need for complex coil modifications and control circuitry, achieving optimal system efficiency with minimal engineering effort and significantly reducing workload.

[0074] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A coil arrangement design method for a multi-relay wireless power transmission structure, applicable to multi-relay wireless power transmission systems with non-equidistant groupings, characterized in that, Includes the following steps: Determine the total transmission distance based on the voltage level of the target power supply scenario. ; In the total transmission distance Under the constraint of arrangement ratio, This represents the second spacing between adjacent groups in a non-equal spacing arrangement. The first gap between the coils in the same group The ratio, and based on the number of coil stages Compared with the arrangement ratio Establish a geometric parameterized model of non-equidistant arrangement; Based on mutual inductance theory, a coupling impedance matrix incorporating adjacent-level coupling and non-adjacent-level cross-level coupling is constructed using the aforementioned geometric parameterization model. And based on the coupling impedance matrix Derive the system energy transfer efficiency model; For the number of coil stages at the aforementioned voltage level Different candidate values ​​are obtained by adjusting the arrangement ratio within a preset range based on the given coil parameters. The value is used to obtain the system efficiency as a function of the arrangement ratio. The changing efficiency distribution curve; Based on the efficiency distribution curve, the optimal number of coil stages that maximizes the system's energy transfer efficiency is determined. and the corresponding optimal arrangement ratio The optimal design scheme for coil arrangement is obtained.

2. The coil arrangement design method for the multi-relay wireless power transmission structure as described in claim 1, characterized in that, The total transmission distance The constraint expression is as follows: In the above formula, Indicates the first The coil and the first The spacing between the coils, , Indicates the first The center position of each coil.

3. The coil arrangement design method for a multi-relay wireless power transmission structure as described in claim 2, characterized in that, In the geometrically parameterized model, each stage of the coil is spaced at a first interval along the energy transmission direction. Second spacing Alternating arrangement, and ,when When it is an odd number, Indicates the first spacing ,when When it is even, Indicates the second spacing .

4. The coil arrangement design method for the multi-relay wireless power transmission structure as described in claim 3, characterized in that, The first spacing With the second spacing They are represented as follows: In the above formula, Indicates the first spacing Quantity, Indicates the second spacing Quantity, , .

5. The coil arrangement design method for a multi-relay wireless power transmission structure as described in claim 4, characterized in that, The energy transfer efficiency model is expressed as follows: In the above formula, Indicates based on the arrangement ratio The system's energy transfer efficiency, Indicates the flow through the first The current in each coil, This indicates the load resistance on the receiving coil. This represents the input voltage of the transmitting coil. It represents the conjugate complex number of the transmitting coil current.

6. The coil arrangement design method for a multi-relay wireless power transmission structure as described in claim 5, characterized in that, The current flowing through the coil is calculated using the following equation: The coupling impedance matrix for The expression for the fully coupled impedance matrix is ​​as follows: In the above formula, This represents the self-impedance of the first coil. This represents the coupling impedance between the first and second coils, where... The imaginary unit, Indicates the operating angular frequency. This indicates the mutual inductance between the first and second coils.

7. A multi-relay wireless power transmission system with non-equidistant grouping, characterized in that, The coil arrangement design method for the multi-relay wireless power transfer structure as described in any one of claims 1 to 6, the multi-relay wireless power transfer system includes... One coil; The coil described includes one transmitting coil arranged in sequence. A relay coil and a receiving coil are placed coaxially. The coils are spaced at a first interval along the energy transmission direction. Second spacing Alternate arrangement.

8. The multi-relay wireless power transmission system with non-equal spacing grouping as described in claim 7, characterized in that, Second spacing Greater than the first spacing .

9. The multi-relay wireless power transmission system with non-equal spacing grouping as described in claim 8, characterized in that, The coils in the same group are integrated with an insulating package.

10. The multi-relay wireless power transmission system with non-equidistant grouping as described in claim 9, characterized in that, When the target power supply scenario has a voltage level of 35kV, a load resistance of 10Ω, a coil self-inductance of 100uH, a coil internal resistance of 0.15Ω, a coil resonant matching capacitor of 11nF, and a coil outer diameter of 160mm, the coil has 6 turns and a specific arrangement ratio. It is 1.2~1.3.

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