Single-relay wireless power transmission system based on ferrite magnetic aggregation structure

Abstract

The present application relates to wireless power transmission circuit and control technical field, specifically relates to a single relay wireless power transmission system based on ferrite magnetic structure, including transmitting coil, receiving coil and one composite relay coil arranged between the two, the composite relay coil is continuously wound by a wire to form first coil part and second coil part, the first coil part faces the transmitting coil, the second coil part faces the receiving coil, two coil parts are oppositely wound, so that the equivalent circumferential current direction on the corresponding working surface of the two is opposite, the composite relay coil is internally provided with a ferrite magnetic member, the ferrite magnetic member and the two coil parts jointly form a magnetic structure, for guiding the effective magnetic flux to the direction of transmitting coil and receiving coil and reducing the leakage magnetic field of non-working area, thus, the effective coupling distance between the transmitting coil and the receiving coil is extended through a composite relay coil, long-distance wireless power transmission is realized, and the number of relay units and resonance parameters is reduced.

Description

Technical Field

[0001] This invention relates to the field of wireless power transmission circuits and control technology, specifically to a single-relay wireless power transmission system based on a ferrite magnetic structure. Background Technology

[0002] In recent years, with the widespread application of Wireless Power Transfer (WPT) technology in electric vehicle charging, consumer electronics, and industrial power supply, its efficiency, convenience, and safety have received widespread attention. Existing wireless power transfer systems typically achieve energy transfer through magnetic coupling between the transmitting and receiving coils. To improve transmission distance and system efficiency, a relay coil is often set between the transmitting and receiving ends to form a multi-coil coupling structure. However, in such systems, in addition to the main coupling between adjacent coils, non-adjacent coupling, i.e., cross coupling, also occurs between the transmitting and receiving coils.

[0003] Cross-coupling alters the equivalent coupling relationship of a system, causing some energy to be transmitted along undesired paths and interfering with the system's resonant state. This leads to decreased transmission efficiency, fluctuations in output characteristics, and reduced system stability. The cross-coupling problem is particularly pronounced when relay coils are introduced to increase transmission distance and capacity, thereby reducing transmission efficiency and overall performance. Furthermore, when the coil spacing or load changes, cross-coupling can further cause fluctuations in output voltage and transmission power, reducing system stability and robustness and limiting its application under complex operating conditions.

[0004] In addition, existing technologies typically suppress cross-coupling by adding compensation circuits or complex tuning networks, but such methods often increase system complexity and additional losses, and traditional coil structures are difficult to effectively weaken non-adjacent coupling. Therefore, a single-relay wireless power transmission system based on ferrite magnetic structure is proposed. Summary of the Invention

[0005] To address the technical problems existing in the prior art, the present invention provides a single-relay wireless power transmission system based on a ferrite magnetic structure.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a single-relay wireless power transmission system based on a ferrite magnetic structure, comprising a transmitting component, a single-relay component, and a receiving component; the transmitting component includes an inverter drive circuit and a transmitting coil. The inverter drive circuit and the transmitting coil The inverter drive circuit is connected to convert the input DC power into AC power, and the transmitting coil... Used for transmitting wireless power; the single relay assembly includes a composite relay coil. The composite relay coil Used to receive and transmit signals from the transmitting coil. The transmitted wireless energy; the receiving component includes a receiving coil. rectifier circuit and load The receiving coil Connected to the load via a rectifier circuit. The receiving coil Used to receive composite relay coils The transmitted radio energy.

[0007] Preferably, it also includes a transmitter compensation component, which includes a main capacitor. The main capacitor With inverter drive circuit and transmitting coil The main capacitor is connected in series. With transmitting coil Forming a natural resonant frequency, at the natural resonant frequency Transmit wireless power.

[0008] Preferably, it further includes a composite relay coil compensation component, the composite relay coil compensation component including a compensation capacitor. The compensation capacitor With composite relay coil The compensation capacitor is connected in series. With composite relay coil Forming the inherent resonant frequency It transmits wireless energy at its inherent resonant frequency.

[0009] Preferably, it further includes a receiver compensation component, the receiver compensation component including a compensation capacitor. The compensation capacitor With receiving coil The compensation capacitor is connected in series. With receiving coil It is connected in parallel with the rectifier circuit.

[0010] Preferably, the receiving coil Includes a filter network, the filter network including filter capacitors. The filter capacitor Parallel connection at load Both ends.

[0011] Preferably, the transmitting coil With composite relay coil Between, composite relay coil With receiving coil Magnetic coupling channels for energy transmission are formed between them; the composite relay coil It includes a first coil section and a second coil section, which are formed by continuously winding a single wire. The first coil section faces the transmitting coil. The second coil portion faces the receiving coil. The first coil section and the second coil section are wound in opposite directions, so that when the same alternating current flows through them, the equivalent circumferential current directions on their corresponding working surfaces are opposite; the composite relay coil An internal ferrite magnetic component is incorporated, which, together with the first and second coil sections, forms a flux control structure to concentrate and guide effective magnetic flux, reducing leakage magnetic field in non-working areas. The reverse winding structure of the first and second coil sections, in conjunction with the magnetic focusing effect of the ferrite magnetic component, forms a structure to suppress the emission coil. With receiving coil The magnetic field distribution of the direct magnetic coupling between the two coils causes the transmitting coil to... With receiving coil direct mutual induction between Reduce to approximately negligible size while maintaining the transmitting coil. With composite relay coil Between and composite relay coils With receiving coil Effective magnetic coupling between them allows electrical energy to primarily travel along... , , Transmission is carried out via a single relay path.

[0012] Preferably, the composite relay coil By configuring the current direction, winding direction, and magnetic field polarity of the upper and lower sub-coils, a magnetic field cancellation region is formed in space, enabling the transmitting coil to... With receiving coil The non-adjacent coupling terms between them satisfy the following condition:

[0013] ;

[0014] in, For transmitting coil and receiving coil The mutual inductance coefficient between them;

[0015] The transmitting coil Composite relay coil With receiving coil The coupling relationship satisfies the following conditions:

[0016] ;

[0017] in, For transmitting coil With receiving coil The cross-coupling coefficient between them For transmitting coil With composite relay coil The coupling coefficient, Composite relay coil With receiving coil The coupling coefficient.

[0018] Preferably, the transmitting coil Composite relay coil With receiving coil The coupling coefficient between them satisfies the following condition:

[0019] ;

[0020] in, For the first The coil and the first Mutual inductance between coils , These are the self-inductances of the corresponding coils.

[0021] Preferably, the transmitting end compensation component and the transmitting coil The composite relay coil compensation component and the composite relay coil form a transmitting-side resonant branch. The receiving end compensation component and the receiving coil form a relay resonant branch. This forms a resonant branch on the receiving side, operating at a preset angular frequency. The following resonant conditions are satisfied by each coil circuit:

[0022] ;

[0023] Where L is the equivalent inductance of the corresponding branch, and C is the compensation capacitor of the corresponding branch;

[0024] By pre-designing and matching the parameters of the compensation capacitor, coil inductance, and load, the system can maintain a resonant operating state under preset operating conditions.

[0025] Preferably, the composite relay coil In suppressing the transmitting coil With receiving coil Under conditions of non-proximity coupling, the direct coupling term between the transmitter and receiver in the equivalent circuit of the system tends to be negligible, making the system dependent on the transmitting coil. With composite relay coil Coupling between and composite relay coils With receiving coil The coupling between them determines the system's ability to maintain a stable energy transfer state even when the coil spacing changes, ignoring the transmitting coil. With receiving coil When the two circuits are not coupled in close proximity, the voltage output by the rectifier circuit satisfies the following condition:

[0026] ;

[0027] in, The output voltage of the rectifier receiver. This is the equivalent voltage of the transmitter inverter. Composite relay coil With receiving coil mutual inductance coefficient, For transmitting coil With composite relay coil mutual inductance coefficient;

[0028] This makes the output voltage of the rectifier circuit equal to the load. Regardless of changes, the wireless power transmission system exhibits constant voltage output characteristics.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] 1. This invention extends the effective coupling distance between the transmitting coil and the receiving coil by using a composite relay coil, thereby realizing medium- and long-distance wireless power transmission. At the same time, it reduces the number of relay units and resonant parameters, eliminates the need for complex control units, simplifies the system structure, and each part can be composed of conventional coils, capacitors, rectifiers and filter circuits without the need for special materials or complex structural designs. It is suitable for various application scenarios such as medium-range wireless power supply, consumer electronics power supply and industrial equipment power supply, and has good engineering promotion value.

[0031] 2. This invention utilizes the magnetic field cancellation effect formed by the composite relay coil to significantly reduce the non-proximity coupling between the transmitting and receiving coils, thus satisfying the requirement... This avoids energy transmission along undesirable paths, allowing the system to primarily transmit energy through the main coupling channel, thereby improving energy utilization efficiency and overall system transmission performance. At the same time, it reduces the system's sensitivity to changes in coil spacing and load, thus improving output stability and system robustness.

[0032] 3. By pre-matching the resonant parameters, this invention can improve the stability, transmission efficiency, and engineering applicability of the wireless power transmission system while maintaining a relatively simple system structure, without introducing complex active adjustment circuits or additional decoupling networks, thus achieving stable wireless power transmission and reducing the difficulty of system design. Attached Figure Description

[0033] Figure 1 This is an overall equivalent circuit diagram of the wireless power transmission system based on a composite relay coil to eliminate cross-coupling in an embodiment of the present invention;

[0034] Figure 2 This is a circuit topology diagram of a wireless power transmission system based on a composite relay coil to eliminate cross-coupling in an embodiment of the present invention;

[0035] Figure 3 This is a diagram showing the system magnetic field distribution in an embodiment of the present invention;

[0036] Figure 4 This is a graph showing the relationship between the coupling coefficients of adjacent and non-adjacent coils in an embodiment of the present invention and the number of coil turns and the coil distance.

[0037] Figure 5 This is a schematic diagram showing the self-inductance of the system's transmitting coil, composite relay coil, and receiving coil as a function of distance in an embodiment of the present invention. Detailed Implementation

[0038] The present invention will be further described below with reference to the accompanying drawings and embodiments, which illustrate the above and other technical features and advantages of the present invention. However, the following embodiments are merely preferred embodiments of the present invention and are not exhaustive.

[0039] Example:

[0040] like Figure 1-5 As shown, this invention provides a single-relay wireless power transmission system based on a ferrite magnetic structure, including a transmitting component, a single-relay component, and a receiving component; the transmitting component drives a transmitting coil through a high-frequency inverter circuit. This generates an alternating magnetic field in space; the single relay component is located at the transmitting coil. With receiving coil Between them, it is used to relay the magnetic field and regulate the distribution of the magnetic field.

[0041] In this embodiment, the transmitting component includes an inverter drive circuit and a main capacitor. Main capacitor switch and transmitting coil The inverter drive circuit is used to convert the input DC power into AC power; the main capacitor... Electrically connected to the inverter drive circuit; main capacitor switch , , and Used to control the main capacitor Connection and disconnection with the inverter drive circuit; transmitting coil With main capacitor Connected to the inverter drive circuit, main capacitor With transmitting coil Forming a natural resonant frequency, at the natural resonant frequency Transmit wireless power;

[0042] It also includes a transmitter compensation component, which includes a main capacitor. main capacitor With inverter drive circuit and transmitting coil Series connection, main capacitor With transmitting coil Forming the inherent resonant frequency At the inherent resonant frequency Transmit wireless power.

[0043] In this embodiment, the composite relay coil It includes a first coil section and a second coil section, which are formed by continuously winding a single wire; wherein the working surface of the first coil section faces the transmitting coil. The working surface of the second coil section faces the receiving coil. The first and second coil sections are wound in opposite directions, so that when the same alternating current flows through them, the equivalent circumferential currents on their corresponding working surfaces are in opposite directions, forming a composite relay coil. The interior is equipped with a ferrite magnetic component, which, together with the first and second coil sections, constitutes a magnetic flux control structure used to focus and guide effective magnetic flux toward the transmitting coil. and receiving coil The distribution of magnetic flux in the direction of operation is optimized to reduce leakage flux in non-working areas. This is achieved through the synergistic effect of the reverse winding structure and ferrite magnetic components, thus improving the performance of the composite relay coil. The surrounding magnetic field distribution is adjusted to maintain the transmitting coil. With composite relay coil Between and composite relay coils With receiving coil While achieving effective magnetic coupling between them, suppress the transmitting coil With receiving coil The direct magnetic coupling between them causes electrical energy to mainly flow along the transmitting coil. - Composite relay coil - Receiver coil Relay coupling path transmission, receiving coil An induced voltage is generated under the action of an alternating magnetic field, and then supplied to the load through subsequent compensation and rectification circuits. It outputs electrical energy, thereby enabling medium- and long-distance wireless power transmission under single-relay conditions, thus achieving stable power supply for the system over medium- and long distances.

[0044] It also includes a composite relay coil compensation component, which includes a compensation capacitor. Compensation capacitor With composite relay coil Series, compensation capacitor With composite relay coil Forming the inherent resonant frequency At the inherent resonant frequency It transmits wireless power to control the distribution of the magnetic field.

[0045] In this embodiment, the receiving component includes a receiving coil. rectifier circuit, load and compensation capacitor Receiving coil Connected to the load via a rectifier circuit. Receiving coil Used to receive composite relay coils Transmitted wireless power; receiving coil Includes a filter network, which includes filter capacitors. Filter capacitor Parallel connection at load Both ends;

[0046] It also includes a receiver compensation component, which includes a compensation capacitor. Compensation capacitor With receiving coil Series, compensation capacitor With receiving coil It is connected in parallel with the rectifier circuit.

[0047] By pre-designing and matching the parameters of each compensation capacitor, coil inductance, and load, the system meets the resonance condition under preset operating conditions, thereby ensuring the stability of energy transmission. Among these, the transmitting coil... Composite relay coil and receiving coil Each of these forms a resonant network with its corresponding compensation capacitor; at the inherent resonant frequency... Under these conditions, each coil satisfies the resonance condition, thus putting the entire system in a resonant operating state; composite relay coil By suppressing non-proximity coupling terms, the system's sensitivity to distance changes is reduced.

[0048] Working principle: transmitting coil With composite relay coil The magnetic coupling between them forms the first main coupling channel; composite relay coil With receiving coil The magnetic coupling between them forms a second main coupling channel, allowing energy to be transferred step by step through the relay path; composite relay coil By orthogonally configuring its winding direction, current direction, and magnetic field polarity, magnetic field modulation is achieved, forming a magnetic field cancellation region in space, thereby controlling the transmitting coil. With receiving coil Suppressing non-proximity coupling between them; under the control of the magnetic field, the transmitting coil With receiving coil The mutual inductance between them decreases significantly, satisfying:

[0049] ;

[0050] This allows the impact of cross-coupling terms on the system to be ignored;

[0051] transmitting coil Composite relay coil With receiving coil The coupling relationship satisfies the following conditions:

[0052] ;

[0053] in, For transmitting coil With receiving coil The cross-coupling coefficient between them For transmitting coil With composite relay coil The coupling coefficient, Composite relay coil With receiving coil The coupling coefficient;

[0054] transmitting coil Composite relay coil With receiving coil The coupling coefficient between them satisfies the following condition:

[0055] ;

[0056] in, For the first The coil and the first Mutual inductance between coils , These are the self-inductances of the corresponding coils;

[0057] With cross-coupling suppressed, the main energy of the system flows along the transmitting coil. —Composite relay coil —Receiving coil The path transmission avoids energy diversion and loss in undesirable paths, improves energy transmission efficiency, and can maintain stable energy transmission and high output efficiency even when the coil distance changes.

[0058] Termination compensation assembly and transmitting coil The composite relay coil compensation component and the composite relay coil constitute the transmitting-side resonant branch. The relay resonant branch is formed by the receiving end compensation component and the receiving coil. This forms a resonant branch on the receiving side, operating at a preset angular frequency. The following resonant conditions are satisfied by each coil circuit:

[0059] ;

[0060] Where L is the equivalent inductance of the corresponding branch, and C is the compensation capacitor of the corresponding branch;

[0061] This improves energy transmission capability and reduces reactive power loss; when the non-proximity coupling between the transmitting and receiving coils is ignored, the system output voltage is mainly determined by the main coupling channel, and the relationship satisfies:

[0062] ;

[0063] in, The output voltage of the rectifier receiver. This is the equivalent voltage of the transmitter inverter. Composite relay coil With receiving coil mutual inductance coefficient, For transmitting coil With composite relay coil mutual inductance coefficient;

[0064] The system output voltage does not change with the load, thus reducing its correlation with load changes and giving the system better output stability. In other words, the correlation between the receiver output voltage and load changes is weakened, thereby improving the system output stability.

[0065] In this embodiment, the hardware components include a transmitter module, a relay module, and a receiver module; specifically:

[0066] The transmitter module includes an inverter circuit, a transmitter compensation network, and a transmitter coil; the inverter circuit can be a full-bridge structure, driven by a control and regulation unit to generate high-frequency current; the compensation network is used to make the transmitter resonate near the operating frequency to ensure effective energy coupling.

[0067] The relay module includes a relay coil and a relay compensation network. The relay compensation network is used to make the relay resonate near the operating frequency to ensure good energy transfer.

[0068] The receiver module includes a receiving coil, a receiver compensation network, a rectifier unit, and a filter capacitor. The receiving coil is coupled to the relay coil but not magnetically coupled to the transmitting coil. The receiving line is rectified and output to the load to achieve energy convergence. The compensation network is used to make the receiver resonate near the operating frequency to ensure stable energy reception. The filter capacitor is used to smooth the pulsating DC output of the rectifier circuit and reduce voltage ripple.

[0069] The theoretical derivation of this invention mainly revolves around circuit theory and coupling coefficients. Circuit theory analyzes the relationships between different circuits, while coupling coefficients are mathematical models for analyzing energy transfer between resonant circuits, intuitively reflecting the energy transfer method. This invention designs a resonant wireless power transfer system where the input frequency and the transmitting coil... When the natural frequencies are equal, the transmitting coil Resonance occurs, generating the maximum magnetic field, and interacts with the composite relay coil. Combined, and then coupled to the receiving coil. , so that the receiving coil A specific resonance also occurs, thereby transferring energy to the load in the receiving coil. Among them, the receiving coil The resonant circuit resonates with the receiving main capacitor, and the following formulas discuss the resonant circuit.

[0070] First, analyze the circuit topology and then list Kirchhoff's voltage laws:

[0071] ;

[0072] in, For transmitting coil The current, Composite relay coil The current, For receiving coil current, The resonant angular frequency, For transmitting coil With receiving coil The mutual induction system between them The imaginary unit used in electrical engineering and complex number operations;

[0073] The corresponding branch currents are:

[0074] ;

[0075] ;

[0076] ;

[0077] in, It can be ignored, therefore:

[0078] ;

[0079] ;

[0080] ;

[0081] Obtain the output voltage of the rectifier receiver. yes:

[0082] ;

[0083] in, This is the equivalent load resistance;

[0084] At this point, the system output voltage is independent of the load, exhibiting constant voltage output characteristics. Simultaneously, based on the current principle, the load current is:

[0085] ;

[0086] in, Input DC voltage;

[0087] Ultimately, the output power at the load end can be determined as follows:

[0088] ;

[0089] The derivation of the above equation neglects the parasitic resistance between the coil and the capacitor. Since the value of its parasitic resistance is extremely small, it can be ignored.

[0090] like Figure 4 The figure shown is a graph illustrating the relationship between the coupling coefficients of adjacent and non-adjacent coils in this invention and the number of coil turns and the coil distance. For transmitting coil With receiving coil The non-adjacent coupling (cross-coupling) coefficient; in composite relay coils Under the influence of [the specific mechanism], the non-adjacent coupling coefficient is extremely low, and its actual impact can be ignored. This ultimately reduces the system's sensitivity to changes in non-adjacent coupling, enabling stable operation even over long distances within a certain range of coils. This verifies the composite relay coil structure, effectively suppressing cross-coupling, reducing changes in the system's equivalent parameters, and allowing the system to maintain stable energy transmission even over long distances within coils.

[0091] In summary, this invention features a novel three-coil structure. Compared to traditional multi-coil WPT systems, by weakening cross-coupling terms, it reduces the system's sensitivity to changes in coil spacing and load, enabling the system to maintain relatively stable energy transfer performance and output characteristics within a certain operating range, thereby improving the system's stability and reliability. It eliminates the need for complex active regulation circuits or additional decoupling networks; cross-coupling suppression can be achieved solely through the structural design of the composite relay coil. While still featuring a multi-coil structure, this invention is simpler to design and has a wider range of applications compared to traditional multi-coil WPT systems.

[0092] The above description is merely a preferred embodiment of the present invention and is illustrative rather than restrictive. Those skilled in the art will understand that many changes, modifications, and even equivalents can be made within the spirit and scope defined by the claims of the present invention, all of which will fall within the protection scope of the present invention.

Claims

1. A single-relay wireless power transmission system based on a ferrite magnetic structure, characterized in that, It includes a transmitting component, a single relay component, and a receiving component; the transmitting component includes an inverter drive circuit and a transmitting coil. The inverter drive circuit and the transmitting coil The inverter drive circuit is connected to convert the input DC power into AC power, and the transmitting coil... Used for transmitting wireless power; the single relay assembly includes a composite relay coil. The composite relay coil Used to receive and transmit signals from the transmitting coil. The transmitted wireless energy; the receiving component includes a receiving coil. rectifier circuit and load The receiving coil Connected to the load via a rectifier circuit. The receiving coil Used to receive composite relay coils The transmitted radio energy.

2. The single-relay wireless power transmission system based on a ferrite magnetic structure as described in claim 1, characterized in that, It also includes a transmitter compensation component, which includes a main capacitor. The main capacitor With inverter drive circuit and transmitting coil The main capacitor is connected in series. With transmitting coil Forming a natural resonant frequency, at the natural resonant frequency Transmit wireless power.

3. The single-relay wireless power transmission system based on a ferrite magnetic structure as described in claim 1, characterized in that, It also includes a composite relay coil compensation component, which includes a compensation capacitor. The compensation capacitor With composite relay coil The compensation capacitor is connected in series. With composite relay coil Forming a natural resonant frequency, at the natural resonant frequency Transmit wireless power.

4. The single-relay wireless power transmission system based on a ferrite magnetic structure as described in claim 1, characterized in that, It also includes a receiver compensation component, which includes a compensation capacitor. The compensation capacitor With receiving coil The compensation capacitor is connected in series. and receiving coil It is connected in parallel with the rectifier circuit.

5. The single-relay wireless power transmission system based on a ferrite magnetic structure as described in claim 1, characterized in that, The receiving coil Includes a filter network, the filter network including filter capacitors. The filter capacitor Parallel connection at load Both ends.

6. The single-relay wireless power transmission system based on a ferrite magnetic structure as described in claim 1, characterized in that, The transmitting coil With composite relay coil Between, composite relay coil With receiving coil Magnetic coupling channels for energy transmission are formed between them; the composite relay coil It includes a first coil section and a second coil section, which are formed by continuously winding a single wire. The first coil section faces the transmitting coil. The second coil portion faces the receiving coil. The first coil section and the second coil section are wound in opposite directions, so that when the same alternating current flows through them, the equivalent circumferential current directions on their corresponding working surfaces are opposite; the composite relay coil An internal ferrite magnetic component is incorporated, which, together with the first and second coil sections, forms a flux control structure to concentrate and guide effective magnetic flux, reducing leakage magnetic field in non-working areas. The reverse winding structure of the first and second coil sections, in conjunction with the magnetic focusing effect of the ferrite magnetic component, forms a structure to suppress the emission coil. With receiving coil The magnetic field distribution of direct magnetic coupling between them.

7. The single-relay wireless power transmission system based on a ferrite magnetic structure as described in claim 6, characterized in that, The composite relay coil By configuring the current direction, winding direction, and magnetic field polarity of the upper and lower sub-coils, a magnetic field cancellation region is formed in space, enabling the transmitting coil to... With receiving coil The non-adjacent coupling terms between them satisfy the following condition: ； in, is the mutual inductance coefficient between the transmitting coil and the receiving coil; The transmitting coil Composite relay coil With receiving coil The coupling relationship satisfies the following conditions: ； in, For transmitting coil With receiving coil The cross-coupling coefficient between them For transmitting coil With composite relay coil The coupling coefficient, Composite relay coil With receiving coil The coupling coefficient.

8. The single-relay wireless power transmission system based on a ferrite magnetic structure as described in claim 7, characterized in that, The transmitting coil Composite relay coil With receiving coil The coupling coefficient between them satisfies the following condition: ； in, For the first The coil and the first Mutual inductance between coils , These are the self-inductances of the corresponding coils.

9. The single-relay wireless power transmission system based on a ferrite magnetic structure as described in claim 1, characterized in that, The transmitter compensation component and the transmitter coil The composite relay coil compensation component and the composite relay coil form a transmitting-side resonant branch. The receiving end compensation component and the receiving coil form a relay resonant branch. This forms a resonant branch on the receiving side, operating at a preset angular frequency. The following resonant conditions are satisfied by each coil circuit: ； Where L is the equivalent inductance of the corresponding branch, and C is the compensation capacitor of the corresponding branch; By pre-designing and matching the parameters of the compensation capacitor, coil inductance, and load, the system can maintain a resonant operating state under preset operating conditions.

10. The single-relay wireless power transmission system based on a ferrite magnetic structure as described in claim 1, characterized in that, The composite relay coil In suppressing the transmitting coil With receiving coil Under conditions of non-proximity coupling, the direct mutual inductance between the transmitter and receiver in the equivalent circuit of the system approaches zero, allowing energy transfer to be handled by the transmitting coil. With composite relay coil Coupling between and composite relay coils With receiving coil The coupling between them determines, ignoring the transmitting coil With receiving coil When the two circuits are not coupled in close proximity, the voltage output by the rectifier circuit satisfies the following condition: ； in, The output voltage of the rectifier receiver. This is the equivalent voltage of the transmitter inverter. Composite relay coil With receiving coil mutual inductance coefficient, For transmitting coil With composite relay coil mutual inductance coefficient; This makes the output voltage of the rectifier circuit equal to the load. Regardless of changes, the wireless power transmission system exhibits constant voltage output characteristics.

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