Three-phase magnetic field coupling type wireless power transmission system

Abstract

The invention provides a three-phase magnetic field coupling type wireless power transmission system, and relates to the technical field of wireless charging, the system comprises a transmitting part, the transmitting part is used for being coupled with a receiving part, and the transmitting part comprises a direct current voltage source, a three-phase high-frequency inverter and a transmitting side three-phase LCC compensation network; the direct-current voltage source is connected to the input end of the three-phase high-frequency inverter, the output end of the three-phase high-frequency inverter is connected to the input end of the compensation network, the compensation network comprises three resonance units, each resonance unit comprises a series compensation capacitor and a transmitting coil, and the series compensation capacitors and the transmitting coils are connected in series to form a series branch. The three series branches integrally form a transmitting side resonant circuit in a Y-shaped connection mode; wherein the three transmitting coils all adopt a double-layer overlapped structure, and the distances between the transmitting coils and the corresponding ferrites are equal; according to the invention, the problem of inductance imbalance caused by a multi-layer structure is solved, the loss is reduced, and the transmission efficiency and the stability of the system are improved.

Description

Technical Field

[0001] This invention relates to the field of wireless charging technology, and more specifically, to a three-phase magnetic field-coupled wireless power transmission system. Background Technology

[0002] Magnetic field-coupled wireless power transfer (MC-WPT) systems are widely used in various industrial sectors due to their resilience to environmental influences, flexibility, and high safety. Some industrial applications typically require MC-WPT systems with high-power energy transfer capabilities; however, traditional single-phase MC-WPT systems cannot meet the power demands of industrial applications due to the limitations of their semiconductor element rated power.

[0003] In related technologies, three-phase MC-WPT systems are typically used to improve output power. The magnetic couplers in three-phase MC-WPT systems often employ multi-layer structures, such as double-layer or triple-layer structures. However, unequal distances between the coils and ferrite in each layer generate unbalanced inductance and mutual inductance, leading to current imbalance in each phase and significant losses. Furthermore, the mutual influence between energy transfer phases makes it difficult to further improve overall transmission efficiency, thus affecting the wireless power transmission effect. Summary of the Invention

[0004] The problem addressed by this invention is how to improve the inductance imbalance and loss caused by multilayer structures.

[0005] To address the aforementioned problems, this invention provides a three-phase magnetic field-coupled wireless power transfer system, comprising a transmitting section for coupling with a receiving section. The transmitting section includes a DC voltage source, a three-phase high-frequency inverter, and a transmitter-side three-phase LCC compensation network. The DC voltage source is connected to the input terminal of the three-phase high-frequency inverter, and the output terminal of the three-phase high-frequency inverter is connected to the input terminal of the transmitter-side three-phase LCC compensation network. The transmitter-side three-phase LCC compensation network includes three resonant units. Each resonant unit includes a series compensation capacitor and a transmitting coil. The series compensation capacitor and the transmitting coil are connected in series to form a series branch. The three series branches are connected in a Y-type manner to form a transmitter-side resonant circuit. All three transmitting coils adopt a double-layer overlapping structure, and the distance between each transmitting coil and the corresponding ferrite is equal. Among the three transmitting coils, the first transmitting coil and the third transmitting coil are both composed of two Q-type coils with opposite magnetic field directions connected diagonally in series, and the second transmitting coil is composed of two Q-type coils with the same magnetic field direction connected vertically in series.

[0006] Optionally, the transmitting-side three-phase LCC compensation network further includes three parallel compensation capacitors and three compensation inductors; In the transmitter-side three-phase LCC compensation network, one end of each parallel compensation capacitor is connected to the connection point of the series compensation capacitor and the compensation inductor in the corresponding series branch, and the other ends of each parallel compensation capacitor are connected together to form a common terminal; the other end of each compensation inductor is connected to the midpoint of each bridge arm in the three-phase high-frequency inverter.

[0007] Optionally, the transmitting coil is disposed on the transmitting-side ferrite substrate. Each portion of the transmitting coil is equidistant from the transmitting-side ferrite substrate.

[0008] Optionally, each of the transmitting coils includes a first sub-coil and a second sub-coil, and the transmitting-side ferrite substrate, the second sub-coil and the first sub-coil are stacked in sequence.

[0009] Optionally, the three-phase high-frequency inverter is a circuit topology composed of six MOSFET switches in a three-phase full-bridge configuration; The three-phase high-frequency inverter is used to control the phase difference of the three-phase AC current flowing through the three transmitting coils by 120 degrees.

[0010] The three-phase magnetic field-coupled wireless power transmission system of this invention employs a double-layer overlapping structure for all coils on the transmitting side, with each coil equidistant from the ferrite core. This structural design ensures consistent distance between each coil and the ferrite core, structurally guaranteeing uniform inductance parameters across all phases. This effectively overcomes the inductance imbalance problem caused by unequal distances between coils and the ferrite core in traditional multi-layer structures. Due to the balance of inductance and mutual inductance, the current in each phase of the three-phase system is more uniform, reducing losses caused by current imbalance. Furthermore, the double-layer overlapping structure reduces uneven magnetic field distribution caused by unequal distances, thereby reducing eddy current losses and further improving the system's transmission efficiency.

[0011] Furthermore, by designing the first and third transmitting coils as two Q-type coils with opposite magnetic field directions connected diagonally in series, and the second transmitting coil as two Q-type coils with the same magnetic field direction connected vertically in series, a complementary magnetic circuit structure is formed in space. This allows the magnetic fields between the coils to mutually restrict and cancel each other out, significantly suppressing phase-to-phase coupling between coils on the same side and achieving magnetic circuit self-decoupling. This reduces energy circulation loss within the transmitting side and improves the efficiency of magnetic field transmission to the receiving side. The LCC compensation network reduces reflection loss and improves the system's transmission efficiency by optimizing the resonant frequency.

[0012] In summary, by optimizing the coil structure and compensation network design, this invention not only solves the inductance imbalance problem caused by the multi-layer structure, but also reduces losses and improves the transmission efficiency and stability of the system.

[0013] This invention provides a three-phase magnetic field-coupled wireless power transfer system, including a receiving section for coupling with a transmitting section. The receiving section includes a receiving-side three-phase LCC compensation network and a rectifier-filter unit. The receiving-side three-phase LCC compensation network includes three resonant units, each of which includes a series compensation capacitor and a receiving coil. The series compensation capacitor and the receiving coil are connected in series to form a series branch, and the three series branches are connected in a Y-type manner to form a receiving-side resonant circuit. The output terminal of the receiving-side resonant circuit is connected to the input terminal of the rectifier-filter unit, and the output terminal of the rectifier-filter unit is used to supply power to the load. The three receiving coils all adopt a double-layer overlapping structure, and the distance between each receiving coil and the corresponding ferrite is equal. The structural arrangement of the receiving coils is geometrically symmetrical with that of the transmitting coils of the transmitting section.

[0014] Optionally, the receiving-side three-phase LCC compensation network further includes three parallel compensation capacitors and three compensation inductors; In the receiving-side three-phase LCC compensation network, one end of each parallel compensation capacitor is connected to the connection point of the series compensation capacitor and the compensation inductor in the corresponding series branch, and the other ends of each parallel compensation capacitor are connected together to form a common terminal; the other end of each compensation inductor is connected to the midpoint of each bridge arm in the rectifier filter unit. The rectifier and filter unit includes a three-phase rectifier composed of six diodes in a full-bridge configuration and a filter capacitor connected in parallel with the load.

[0015] Optionally, the receiving coil is disposed on a ferrite substrate on the receiving side; Each portion of the receiving coil is equidistant from the receiving-side ferrite substrate.

[0016] Optionally, each of the receiving coils includes a third sub-coil and a fourth sub-coil, and the receiving-side ferrite substrate, the fourth sub-coil and the third sub-coil are stacked sequentially.

[0017] Optionally, there is no magnetic coupling interference between the three receiving coils, and there is no magnetic coupling interference between any of the receiving coils of the receiving section and any of the transmitting coils of the transmitting section at different phases; The three receiving coils and the three transmitting coils form three main coupled energy transmission channels, wherein the three main coupled energy transmission channels are respectively the first coupling channel formed by the first receiving coil and the corresponding transmitting coil, the second coupling channel formed by the second receiving coil and the corresponding transmitting coil, and the third coupling channel formed by the third receiving coil and the corresponding transmitting coil.

[0018] The three-phase magnetic field-coupled wireless power transmission system of this invention employs a receiving section with three receiving coils arranged in a double-layer overlapping structure, each coil equidistant from the ferrite core. This structurally ensures the consistency of the inductance parameters of each phase coil on the receiving side, achieving overall system parameter balance in conjunction with the transmitting side. Furthermore, the geometrically symmetrical arrangement of the receiving and transmitting coils forms a spatially matched magnetic circuit structure, enabling each coil on the receiving side to efficiently capture the magnetic field energy of the corresponding phase on the transmitting side while effectively suppressing mutual interference between receiving coils and cross-coupling from non-corresponding phases on the transmitting side. This achieves efficient energy collection and interference suppression on the receiving side. Combined with the resonant characteristics of the three-phase LCC compensation network on the receiving side, the system achieves better impedance matching, reduces energy reflection, and, with the optimized design of the rectifier and filter unit, ultimately provides a stable and efficient DC power output to the load, significantly improving the overall transmission efficiency and output stability of the system under complex operating conditions. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall circuit of an embodiment of the present invention; Figure 2 This is a schematic diagram of the equivalent circuit of an embodiment of the present invention; Figure 3 The diagram shows a 3D model of the magnetic coupler and a model of the transmitting (receiving) side of the magnetic coupler according to an embodiment of the present invention. Figure 4 This is a schematic diagram showing the direction of magnetic flux in a three-phase coil. Figure 5 This is a model diagram of a three-phase transmitting coil (receiving coil) according to an embodiment of the present invention; Figure 6 This is a phase current waveform diagram of each phase under a load of 5Ω according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the output current of the system under a load of 5Ω-20Ω according to an embodiment of the present invention. Detailed Implementation

[0020] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0021] It should be understood that the various steps described in the method embodiments of the present invention may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this respect.

[0022] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first," "second," etc., mentioned in this invention are used only to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0023] It should be noted that the terms "a" and "a plurality of" used in this invention are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0024] The names of the messages or information exchanged between the multiple devices in the embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of these messages or information.

[0025] Combination Figure 1 As shown, the present invention provides a three-phase magnetic field-coupled wireless power transfer system, including a transmitting section, wherein the transmitting section is used for coupling with a receiving section. The transmitting section includes a DC voltage source, a three-phase high-frequency inverter, and a transmitter-side three-phase LCC compensation network. The DC voltage source is connected to the input terminal of the three-phase high-frequency inverter, and the output terminal of the three-phase high-frequency inverter is connected to the input terminal of the transmitter-side three-phase LCC compensation network. The transmitter-side three-phase LCC compensation network includes three resonant units. Each resonant unit includes a series compensation capacitor and a transmitting coil. The series compensation capacitor and the transmitting coil are connected in series to form a series branch. The three series branches are connected in a Y-type manner to form a transmitter-side resonant circuit. All three transmitting coils adopt a double-layer overlapping structure, and the distance between each transmitting coil and the corresponding ferrite is equal. Among the three transmitting coils, the first transmitting coil and the third transmitting coil are both composed of two Q-type coils with opposite magnetic field directions connected diagonally in series, and the second transmitting coil is composed of two Q-type coils with the same magnetic field direction connected vertically in series.

[0026] Specifically, in combination Figure 1As shown, it includes: DC voltage source U D A three-phase high-frequency inverter, consisting of a transmitting coil L A and compensation inductor L FA Compensation capacitor C FA C PA The resonant unit is composed of a transmitting coil L. B and compensation inductor L FB Compensation capacitor C FB C PB The resonant unit is composed of a transmitting coil L. C and compensation inductor L FC Compensation capacitor C FC C PC The resonant unit is composed of three phases. The three-phase high-frequency inverter inverts the output DC power into three high-frequency AC power with a phase difference of 120 degrees. The high-frequency AC power is transmitted to the receiving side through the magnetic field generated on the transmitting side. After being converted into DC power by the rectifier and filter capacitor, it charges the battery load.

[0027] Figure 2 The diagram shown is the equivalent circuit of the system, with DC power supply U. D and U AI U BI U CI The relationship between them and the equivalent AC load R E With load R B The relationship between them can be represented as: , ; Specifically, the DC voltage source U in the transmitting section D As the system's power source, it provides a stable DC voltage. The three-phase high-frequency inverter consists of six MOSFET switches connected in a T-connection. The inverter converts the DC voltage from the DC voltage source UD into three high-frequency AC currents with a 120-degree phase difference. This phase difference design ensures the balance of the three-phase currents and reduces losses caused by current imbalance. The transmitter-side three-phase LCC compensation network includes three series branches, each with a series compensation capacitor C. PA C PB C PC and a transmitting coil L A L B L C The corresponding series connections are used. All series branches are connected in a Y-shape to form a transmitter-side resonant circuit. The LCC compensation network optimizes the resonant frequency and impedance matching, reduces reflection loss, and improves transmission efficiency.

[0028] Three transmitting coils L A L B L CBoth coils employ a double-layer overlapping structure, with each coil equidistant from the ferrite core. Specifically, the first and third transmitting coils consist of two Q-type coils connected diagonally in series with opposite magnetic field directions. This design cancels out the magnetic fields of the two coils, reducing eddy current losses and balancing self-inductance and mutual inductance. The second transmitting coil consists of two Q-type coils connected vertically in series with the same magnetic field direction. This design ensures consistent magnetic field direction, enhances magnetic field strength, and improves energy transfer efficiency.

[0029] Combination Figure 3 and Figure 5 As shown, the transmitting coils employ a double-layer overlapping structure, with each coil equidistant from the ferrite core. This design ensures that the self-inductance and mutual inductance of each coil are physically balanced, reducing inductance imbalance caused by structural asymmetry. Specifically, the first and third transmitting coils are composed of two Q-type coils connected diagonally in series with opposite magnetic field directions. This design allows the magnetic fields of the two coils to cancel each other out, reducing eddy current losses while balancing self-inductance and mutual inductance.

[0030] The three-phase magnetic field-coupled wireless power transmission system of this invention employs a double-layer overlapping structure for all coils on the transmitting side, with each coil equidistant from the ferrite core. This structural design ensures consistent distance between each coil and the ferrite core, structurally guaranteeing uniform inductance parameters across all phases. This effectively overcomes the inductance imbalance problem caused by unequal distances between coils and the ferrite core in traditional multi-layer structures. Due to the balance of inductance and mutual inductance, the current in each phase of the three-phase system is more uniform, reducing losses caused by current imbalance. Furthermore, the double-layer overlapping structure reduces uneven magnetic field distribution caused by unequal distances, thereby reducing eddy current losses and further improving the system's transmission efficiency.

[0031] Furthermore, by designing the first and third transmitting coils as two Q-type coils with opposite magnetic field directions connected diagonally in series, and the second transmitting coil as two Q-type coils with the same magnetic field direction connected vertically in series, a complementary magnetic circuit structure is formed in space. This allows the magnetic fields between the coils to mutually restrict and cancel each other out, significantly suppressing phase-to-phase coupling between coils on the same side and achieving magnetic circuit self-decoupling. This reduces energy circulation loss within the transmitting side and improves the efficiency of magnetic field transmission to the receiving side. The LCC compensation network reduces reflection loss and improves the system's transmission efficiency by optimizing the resonant frequency.

[0032] In summary, by optimizing the coil structure and compensation network design, this invention not only solves the inductance imbalance problem caused by the multi-layer structure, but also reduces losses and improves the transmission efficiency and stability of the system.

[0033] Optionally, the transmitting-side three-phase LCC compensation network further includes three parallel compensation capacitors and three compensation inductors; In the transmitter-side three-phase LCC compensation network, one end of each parallel compensation capacitor is connected to the connection point of the series compensation capacitor and the compensation inductor in the corresponding series branch, and the other ends of each parallel compensation capacitor are connected together to form a common terminal; the other end of each compensation inductor is connected to the midpoint of each bridge arm in the three-phase high-frequency inverter.

[0034] Specifically, in combination Figure 1 As shown, in the three-phase LCC compensation network on the transmitting side, each parallel compensation capacitor (C) FA C FB C FC One end of the capacitor is connected to the corresponding series compensation capacitor (C) in the series branch. PA C PB C PC ) and compensation inductor (L FA L FB L FC At the connection points, the other ends of each parallel compensation capacitor are connected together to form a common terminal; the other end of each compensation inductor is connected to the midpoint of each bridge arm (e.g., ...). Figure 1 Near points A, B, and C in the diagram, which is the midpoint of the three-phase high-frequency inverter on the transmitting side.

[0035] In this optional embodiment, by adding a parallel compensation capacitor, the LCC compensation network on the transmitting side can more accurately optimize the resonant frequency, reduce reflection loss, and improve the system's transmission efficiency. The addition of the parallel compensation capacitor helps stabilize the current on the transmitting side, reducing the impact of load changes or fluctuations during transmission on the system, thereby improving system stability. By optimizing impedance matching, the system can operate stably under different load conditions, improving the system's reliability and adaptability.

[0036] Optionally, the transmitting coil is disposed on the transmitting-side ferrite substrate. Each portion of the transmitting coil is equidistant from the transmitting-side ferrite substrate.

[0037] Optionally, each of the transmitting coils includes a first sub-coil and a second sub-coil, and the transmitting-side ferrite substrate, the second sub-coil and the first sub-coil are stacked in sequence.

[0038] Specifically, ferrite substrates play a crucial role in magnetically coupled wireless power transfer (MC-WPT) systems. Ferrite materials, with their high permeability and low loss characteristics, effectively enhance magnetic field coupling strength and improve system transmission efficiency. Furthermore, ferrite substrates provide excellent mechanical support, ensuring the stability and symmetry of the coils. Figure 3 As shown, three transmitting coils (L A L B L CAll are mounted on the ferrite substrate on the transmitting side. The distance between each part of each transmitting coil and the ferrite substrate on the transmitting side is equal, thereby ensuring that the distance between each coil and the ferrite substrate is consistent, thus keeping the self-inductance and mutual inductance of each coil physically balanced.

[0039] Taking the transmitting coil LA as an example, coil LA is composed of a first sub-coil A1 and a second sub-coil A2 connected in series. Exemplarily, during installation, the first sub-coil A1 is directly laid or fixed to the surface of the transmitting-side ferrite substrate, while the second sub-coil A2 is stacked on top of the first sub-coil A1. Through this ferrite substrate-second sub-coil (upper layer)-first sub-coil (lower layer) stacking method of this embodiment, and by precisely controlling the thickness and turn spacing of the sub-coils, it can be ensured that the average distance or equivalent distance from each turn of coil LA (whether it is the upper layer A2 or the lower layer A1) to the surface of the ferrite substrate is equal. Similarly, other transmitting coils (L_B, L_C) and all receiving coils (La, Lb, Lc) adopt the same stacking and fixing method. This makes each phase coil, as a whole, have a completely consistent relative positional relationship with the corresponding side ferrite substrate, thereby ensuring a high balance of the self-inductance and mutual inductance values ​​of each phase coil. Specifically: The first and third transmitting coils are composed of two Q-type coils with opposite magnetic field directions connected diagonally in series, placed on a ferrite substrate, ensuring that each part of the coil is equidistant from the ferrite substrate. The second transmitting coil is composed of two Q-type coils with the same magnetic field direction connected vertically in series, placed on the ferrite substrate, ensuring that each part of the coil is equidistant from the ferrite substrate. By ensuring that each part of the coil is equidistant from the ferrite substrate, the inductance imbalance problem caused by structural asymmetry is reduced, improving the system's transmission efficiency. The diagonally connected Q-type coils cause the magnetic fields of the two coils to cancel each other out, reducing eddy current losses and balancing self-inductance and mutual inductance.

[0040] This embodiment addresses the inductance imbalance and loss issues caused by multilayer structures by placing the transmitting coils on a ferrite substrate and ensuring that each part of the coil is equidistant from the ferrite substrate. This three-phase magnetic field-coupled wireless power transfer system effectively solves these problems while improving transmission efficiency, stability, and reliability. This design not only meets the industrial application requirements for high-power energy transfer but also enhances the overall system performance.

[0041] Optionally, the three-phase high-frequency inverter is a circuit topology composed of six MOSFET switches in a three-phase full-bridge configuration; The three-phase high-frequency inverter is used to control the phase difference of the three-phase AC current flowing through the three transmitting coils by 120 degrees.

[0042] Specifically, in combination Figure 1As shown, the three-phase high-frequency inverter is composed of six MOSFET switches in a three-phase full-bridge configuration, and its input is connected to a DC voltage source U. D The output is connected to a three-phase LCC compensation network on the transmitting side. This topology efficiently converts DC voltage into three-phase high-frequency AC voltage. The three-phase high-frequency inverter controls the phase of the three-phase AC current flowing through the three transmitting coils, ensuring a 120-degree phase difference between each phase. This phase difference design ensures the balance of the three-phase current and reduces losses caused by current imbalance. DC voltage source U D A stable DC voltage is provided to the input of a three-phase high-frequency inverter. The output of the three-phase high-frequency inverter is connected to the input of the three-phase LCC compensation network on the transmitting side. By controlling the switching state of the MOSFETs, the DC voltage is inverted into a three-phase high-frequency AC voltage, which drives the transmitting coil to generate a high-frequency magnetic field. This efficient conversion of DC voltage into three-phase high-frequency AC voltage enables wireless power transmission. By controlling the phase difference of the three-phase AC current to 120 degrees, the balance of the three-phase current is ensured, reducing losses caused by current imbalance and improving the system's transmission efficiency.

[0043] This invention provides a three-phase magnetic field-coupled wireless power transfer system, including a receiving section for coupling with a transmitting section. The receiving section includes a receiving-side three-phase LCC compensation network and a rectifier-filter unit. The receiving-side three-phase LCC compensation network includes three resonant units, each of which includes a series compensation capacitor and a receiving coil. The series compensation capacitor and the receiving coil are connected in series to form a series branch, and the three series branches are connected in a Y-type manner to form a receiving-side resonant circuit. The output terminal of the receiving-side resonant circuit is connected to the input terminal of the rectifier-filter unit, and the output terminal of the rectifier-filter unit is used to supply power to the load. The three receiving coils all adopt a double-layer overlapping structure, and the distance between each receiving coil and the corresponding ferrite is equal. The structural arrangement of the receiving coils is geometrically symmetrical with that of the transmitting coils of the transmitting section.

[0044] Specifically, in combination Figure 1 As shown, the receiving coil L a and compensation inductor L Sa Compensation capacitor C fa C Sa The resonant unit is composed of a receiving coil L. b and compensation inductor L Sb Compensation capacitor C fb C Sb The resonant unit is composed of a receiving coil L. c and compensation inductor L Sc Compensation capacitor Cfc C Sc The resonant unit consists of a three-phase rectifier and a filter capacitor C. F and battery load R B The three-phase high-frequency inverter inverts the output DC power into three high-frequency AC power sources with a phase difference of 120 degrees. The high-frequency AC power is transmitted to the receiving side through the magnetic field generated on the transmitting side. After being rectified and filtered by the capacitor, it is converted into DC power to charge the battery load.

[0045] Figure 2 The diagram shown is the equivalent circuit of the system, with DC power supply U. D and U AI U BI U CI The relationship between them and the equivalent AC load R E With load R B The relationship between them can be represented as: , ; Specifically, the DC voltage source U in the transmitting section D As the system's power source, it provides a stable DC voltage. The three-phase high-frequency inverter consists of six MOSFET switches connected in a T-connection. The inverter converts the DC voltage from the DC voltage source UD into three high-frequency AC currents with a 120-degree phase difference. This phase difference design ensures the balance of the three-phase currents and reduces losses caused by current imbalance. The transmitter-side three-phase LCC compensation network includes three series branches, each with a series compensation capacitor C. PA C PB C PC and a transmitting coil L A L B L C The corresponding series connections are used. All series branches are connected in a Y-shape to form a transmitter-side resonant circuit. The LCC compensation network optimizes the resonant frequency and impedance matching, reduces reflection loss, and improves transmission efficiency.

[0046] Three transmitting coils L A L B L C Both coils employ a double-layer overlapping structure, with each coil equidistant from the ferrite core. Specifically, the first and third transmitting coils consist of two Q-type coils connected diagonally in series with opposite magnetic field directions. This design cancels out the magnetic fields of the two coils, reducing eddy current losses and balancing self-inductance and mutual inductance. The second transmitting coil consists of two Q-type coils connected vertically in series with the same magnetic field direction. This design ensures consistent magnetic field direction, enhances magnetic field strength, and improves energy transfer efficiency.

[0047] The three receiving coils L of the receiving section a L b L c Geometrically symmetrical to the transmitting coil, both employ a double-layer overlapping structure, with each coil equidistant from the ferrite core. This symmetrical design further ensures the balance of inductance and mutual inductance, reducing losses caused by current imbalance. The receiving-side three-phase LCC compensation network comprises three series branches, each with a series compensation capacitor C. SA C SB C SC It is constructed by connecting a corresponding receiving coil in series. All series branches are connected in a Y-shape to form a receiving-side resonant circuit. The receiving-side LCC compensation network functions similarly to the transmitting-side network, optimizing the resonant frequency and impedance matching to reduce reflection loss. The output of the receiving-side resonant circuit is connected to the input of a rectifier-filter unit. The rectifier-filter unit converts high-frequency AC power to DC power to supply the load. The output of the rectifier-filter unit is connected to the battery load R. B In terms of power supply, this design ensures a constant current output characteristic independent of the load, meaning that the output current is approximately constant and unaffected by load changes.

[0048] Combination Figure 3 and Figure 5 As shown, both the transmitting and receiving coils employ a double-layer overlapping structure, with each coil equidistant from the ferrite core. This design ensures that the self-inductance and mutual inductance of each coil are physically balanced, reducing inductance imbalance caused by structural asymmetry. Specifically, the first and third transmitting coils are composed of two Q-type coils with opposite magnetic field directions connected diagonally in series. This design allows the magnetic fields of the two coils to cancel each other out, reducing eddy current losses and balancing self-inductance and mutual inductance. The second transmitting coil is composed of two Q-type coils with the same magnetic field direction connected vertically in series. This design ensures consistent magnetic field direction, enhances magnetic field strength, and improves energy transmission efficiency. The receiving coil is geometrically symmetrical with the transmitting coil, ensuring inductance and mutual inductance balance and reducing losses caused by current imbalance.

[0049] Combination Figure 3 As shown, Figure 3 The 3D model of the magnetic coupler shows the layout of the transmitting and receiving coils. Both the transmitting and receiving coils are double-layered structures, and each coil is equidistant from the ferrite core. Figure 5 The plan view of a single-sided transmitting / receiving coil further illustrates the specific arrangement of the coils. Half of each phase coil is placed close to the ferrite core on the lower layer, and the other half is placed on the upper layer, ensuring that the distance between each phase coil and the ferrite core is equal.

[0050] Combination Figure 4As shown, the decoupling design of the magnetic coupler is geometrically symmetrical, with the coils on the emitter and receiver sides arranged symmetrically. This eliminates interphase mutual inductance between coils on the same side and cross-coupling between coils on different sides. The A-phase coil and the C-phase coil are not coupled due to the mutual cancellation of their magnetic flux directions. The B-phase coil is also decoupled from the A-phase and C-phase coils because the total magnetic flux is zero. Specifically, the schematic diagram shows the current and magnetic flux directions of the A(a), B(b), and C(c) phase coils. Figure 4 The displayed directions of current and magnetic flux in phases A(a), B(b), and C(c) show that half of the magnetic flux in both phases A(a) and C(c) is perpendicular to the plane and flows inwards, while the other half flows perpendicular to the plane and outwards. Therefore, the magnetic flux generated by phase A and flowing through phase C is zero; similarly, the magnetic flux generated by phase C and flowing through phase A is zero. Thus, phase A and phase C are not coupled. Furthermore, since the magnetic flux in phase B is perpendicular to the plane and flows inwards, the total magnetic flux generated by phase B and flowing through phases A(a) and C(c) is zero. Therefore, phase B is also decoupled from phases A(a) and C(c).

[0051] For example, referring to Table 1, simulation verification was performed using a 3D model of a three-phase decoupled magnetic coupler built in Maxwell. The results show that the designed magnetic coupler only has M Aa M Bb and M Cc The three main couplings and the remaining 12 pairs of interphase couplings and cross couplings are all less than 1uH, and their impact on the system can be approximated as negligible.

[0052] Table 1 Simulation parameter values ​​of the three-phase self-decoupling magnetic coupler

[0053] This embodiment achieves load-independent constant current output by utilizing a well-designed LCC compensation network and the characteristics of a decoupled magnetic coupler. The output current is approximately constant and unaffected by load variations. For example, under load variations ranging from 5 to 20 ohms, the overall relative fluctuation of the system's output current is only 4%, demonstrating excellent constant current output characteristics.

[0054] Optionally, the receiving-side three-phase LCC compensation network further includes three parallel compensation capacitors and three compensation inductors; In the receiving-side three-phase LCC compensation network, one end of each parallel compensation capacitor is connected to the connection point of the series compensation capacitor and the compensation inductor in the corresponding series branch, and the other ends of each parallel compensation capacitor are connected together to form a common terminal; the other end of each compensation inductor is connected to the midpoint of each bridge arm in the rectifier filter unit. The rectifier and filter unit includes a three-phase rectifier composed of six diodes in a full-bridge configuration and a filter capacitor connected in parallel with the load.

[0055] Specifically, in combination Figure 1 As shown, in the three-phase LCC compensation network on the receiving side, each parallel compensation capacitor (C) fa C fb C fc One end of the capacitor is connected to the series compensation capacitor C in the corresponding series branch. Sa C Sb C Sc With compensation inductor ( L fa 、L fb 、L fc At the connection points, the other ends of each parallel compensation capacitor are connected together to form a common terminal; the other end of each compensation inductor is connected to the midpoint of each bridge arm (e.g., ...). Figure 1 Near points a, b, and c in the diagram, which is the midpoint of the receiving-side rectifier and filter unit.

[0056] In this optional embodiment, by adding a compensating inductor, the LCC compensation network on the receiving side can more accurately optimize impedance matching, reduce reflection loss, and improve the transmission efficiency of the system.

[0057] The addition of a compensating inductor helps stabilize the voltage on the receiving side, reducing the impact of load changes or fluctuations during transmission on the system, thereby improving system stability. By stabilizing the current and voltage, the system can operate stably under different load conditions, improving its reliability and adaptability.

[0058] Optionally, the receiving coil is disposed on a ferrite substrate on the receiving side; Each portion of the receiving coil is equidistant from the receiving-side ferrite substrate.

[0059] Optionally, each of the receiving coils includes a third sub-coil and a fourth sub-coil, and the receiving-side ferrite substrate, the fourth sub-coil and the third sub-coil are stacked sequentially.

[0060] Specifically, the specific arrangement method is combined Figure 3 and Figure 5As shown, the receiving side includes a receiving ferrite substrate and three receiving coils mounted thereon. The transmitting and receiving ferrite substrates are spatially parallel and opposite each other, separated by an air gap. Each transmitting coil and receiving coil adopts a double-layer overlapping structure. Taking the transmitting coil LA as an example, coil LA is composed of a first sub-coil A1 and a second sub-coil A2 connected in series. Exemplarily, during installation, the first sub-coil A1 is directly laid or fixed on the surface of the transmitting ferrite substrate, and the second sub-coil A2 is stacked on top of the first sub-coil A1. Through this ferrite substrate-second sub-coil (upper layer)-first sub-coil (lower layer) stacking method of this embodiment, and by precisely controlling the thickness and turn spacing of the sub-coils, it can be ensured that the average distance or equivalent distance from each turn of coil LA (whether it is the upper layer A2 or the lower layer A1) to the surface of the ferrite substrate is equal. Similarly, other transmitting coils (L_B, L_C) and all receiving coils (La, Lb, Lc) adopt the same stacking and fixing method. This ensures that each phase coil, as a whole, has a completely consistent relative position with the corresponding ferrite substrate, thereby guaranteeing a high degree of balance between the self-inductance and mutual inductance of each phase coil.

[0061] Specifically: The first and third transmitting coils are composed of two Q-type coils with opposite magnetic field directions connected diagonally in series, placed on a ferrite substrate, ensuring that each part of the coil is equidistant from the ferrite substrate. The second transmitting coil is composed of two Q-type coils with the same magnetic field direction connected vertically in series, placed on the ferrite substrate, ensuring that each part of the coil is equidistant from the ferrite substrate. By ensuring that each part of the coil is equidistant from the ferrite substrate, the inductance imbalance problem caused by structural asymmetry is reduced, improving the system's transmission efficiency. The diagonally connected Q-type coils cause the magnetic fields of the two coils to cancel each other out, reducing eddy current losses and balancing self-inductance and mutual inductance.

[0062] Three receiving coils (L) a L b L c All are mounted on the receiving-side ferrite substrate. The distance between each part of each receiving coil and the receiving-side ferrite substrate is equal, ensuring consistent distance between each coil and the substrate, thus maintaining a physical balance in the self-inductance and mutual inductance of each coil. Each receiving coil employs a double-layer overlapping structure, with each part of each coil equidistant from the ferrite substrate. Specifically: geometric symmetry with the transmitting coil ensures balance inductance and mutual inductance, reducing losses caused by current imbalance. By ensuring equal distance between each part of each coil and the ferrite substrate, inductance imbalance caused by structural asymmetry is reduced, improving the system's transmission efficiency. The series connection of the Q-type coils ensures a consistent magnetic field direction, enhancing magnetic field strength and improving energy transmission efficiency. Figure 3This is a 3D model of a magnetic coupler, showing the layout of the transmitting and receiving coils. Each coil is mounted on a corresponding ferrite substrate, and all parts of each coil are equidistant from the ferrite substrate. Figure 5 The plan view of the single-sided transmitting / receiving coil further illustrates the specific coil arrangement. Half of each coil is placed flush against the ferrite substrate on the lower layer, and the other half on the upper layer, ensuring that each phase coil is equidistant from the ferrite substrate. By placing the transmitting and receiving coils on the ferrite substrate and ensuring that each part of the coil is equidistant from the substrate, inductance imbalance caused by structural asymmetry is reduced, improving the system's transmission efficiency. The diagonally connected Q-type coil design reduces eddy current losses while balancing self-inductance and mutual inductance. The geometrically symmetrical coil arrangement reduces losses caused by current imbalance, improving system stability. The vertically connected Q-type coil design enhances the magnetic field strength and improves energy transfer efficiency.

[0063] In summary, by placing the transmitting and receiving coils on a ferrite substrate and ensuring that each part of the coil is equidistant from the ferrite substrate, this embodiment of the three-phase magnetic field-coupled wireless power transfer system can more effectively solve the inductance imbalance and loss problems caused by multi-layer structures, while improving the system's transmission efficiency, stability, and reliability. This design not only meets the industrial application requirements for high-power energy transfer but also enhances the overall performance of the system.

[0064] Optionally, there is no magnetic coupling interference between the three receiving coils, and there is no magnetic coupling interference between any of the receiving coils of the receiving section and any of the transmitting coils of the transmitting section at different phases; The three receiving coils and the three transmitting coils form three main coupled energy transmission channels, wherein the three main coupled energy transmission channels are respectively the first coupling channel formed by the first receiving coil and the corresponding transmitting coil, the second coupling channel formed by the second receiving coil and the corresponding transmitting coil, and the third coupling channel formed by the third receiving coil and the corresponding transmitting coil.

[0065] Specifically, the three main coupled energy transmission channels (i.e., the first transmitting coil L) A With the corresponding receiving coil L a The channel, the second transmitting coil L B With the corresponding receiving coil L b The channel, the third transmitting coil L C With the corresponding receiving coil L c (The channel). The structure of the receiving coil is geometrically symmetrical to that of the transmitting coil: L A With L aTheir structures are completely identical, both consisting of two Q-type coils connected diagonally in series with opposite magnetic field directions; L B With L b Their structures are completely identical, both consisting of two Q-type coils with the same magnetic field direction connected in series; L C With L c The structure is completely identical to that of L. A L a The reverse Q-type coils are connected in diagonal series. This embodiment uses a geometrically symmetrical design to ensure that the magnetic circuit parameters (such as the number of coil turns, wire diameter, and spatial orientation) of the in-phase coils are perfectly matched, providing structural support for directional energy coupling.

[0066] Meanwhile, the distance between each transmitting coil and the ferrite core is equal, and the distance between each receiving coil and the ferrite core is also equal. This design keeps the self-inductance of the three-phase coils balanced. Combined with the simulation data in Table 1 above, the transmitting side L... A =75.892μH, L B =76.605μH, L C =75.953μH, receiver-side L a =75.899μH, L b =76.61μH, L c =75.957μH, with extremely small self-inductance deviation; and the mutual inductance of the in-phase coils (M Aa =23.075μH, M Bb =22.288μH, M Cc The mutual inductance (23.07 μH) is much greater than that of other coupling relationships, ensuring consistent impedance matching characteristics of the in-phase coils. This makes it easier for energy to be transferred along the in-phase path rather than leaking to other phases. The three main channels achieve effective coupling only between in-phase coils through the combined effect of in-phase coil flux direction matching and non-main channel flux cancellation, while there is no coupling between non-phase coils.

[0067] For in-phase coils: with L A With L a For example, L A A series of reverse-direction Q-type coils connected diagonally generates a symmetrical magnetic flux when current flows through it, with half of the flux perpendicular to the plane inward and the other half perpendicular to the plane outward; L a Because of L A Geometrically symmetric, its magnetic flux direction is parallel to L A A perfect match, with both spatially aligned. L A The generated magnetic flux can pass completely through L a and in L a An effective current is induced in the middle, realizing the energy from L A To L a Directed transmission. Similarly, L BThe "all-inward" magnetic flux and L b "Omnidirectional" magnetic flux matching, L C The "half-inward, half-outward" magnetic flux and L c The "half-inward, half-outward" magnetic flux matching forms L respectively. B -L b L C -L c Two main coupling channels.

[0068] For non-primary channels (such as L) A With L b L B With L a etc): with L A With L b For example, L A The "half-inward, half-outward" magnetic flux passes through L b (When considering the "all-inward" magnetic flux characteristic), the "inward" portion interacts with L. b Magnetic flux superposition, the "outward" part and L b The magnetic flux cancels out, and eventually flows through L b L A The total magnetic flux approaches zero; simulation data shows that the mutual inductance of such non-master channels (e.g., M) is close to zero. Ab =0.202μH, M Ba =0.202μH) are all less than 1μH, which is much smaller than the mutual inductance value of the main channel. Therefore, no effective current can be induced in the non-phase receiving coil, and thus no energy is transmitted.

[0069] As shown in Table 1 above, the mutual inductance values ​​of the three main channels are all in the range of 22-23 μH (M). Aa =23.075μH, M Bb =22.288μH, M Cc =23.07μH), which is the core path for energy transfer; the mutual inductance of all non-main channels (such as L) A With L b M Ab =0.202μH, L B With L a M Ba =0.202μH, L C With L a M Ca The values ​​of 0.582μH and 0.582μH are all less than 1μH, so their impact on the system's energy transfer can be completely ignored, further proving that energy is almost entirely transferred through the three main channels.

[0070] This embodiment simplifies the energy transmission path, preventing energy from flowing through non-main channels, thus avoiding power waste caused by coupling losses and improving system transmission efficiency. Furthermore, it eliminates the need for additional decoupling circuits (such as decoupling inductors and capacitors), achieving self-decoupling solely through structural design, simplifying system hardware and control algorithms. It avoids power fluctuations caused by non-main channel coupling during offset, and combined with a three-phase LCC compensation network, the overall relative fluctuation of the system output current is only 4% when the load varies within the range of 5-20Ω, exhibiting excellent constant current output characteristics.

[0071] The three-phase magnetic field-coupled wireless power transmission system of this invention employs a receiving section with three receiving coils arranged in a double-layer overlapping structure, each coil equidistant from the ferrite core. This structurally ensures the consistency of the inductance parameters of each phase coil on the receiving side, achieving overall system parameter balance in conjunction with the transmitting side. Furthermore, the geometrically symmetrical arrangement of the receiving and transmitting coils forms a spatially matched magnetic circuit structure, enabling each coil on the receiving side to efficiently capture the magnetic field energy of the corresponding phase on the transmitting side while effectively suppressing mutual interference between receiving coils and cross-coupling from non-corresponding phases on the transmitting side. This achieves efficient energy collection and interference suppression on the receiving side. Combined with the resonant characteristics of the three-phase LCC compensation network on the receiving side, the system achieves better impedance matching, reduces energy reflection, and, with the optimized design of the rectifier and filter unit, ultimately provides a stable and efficient DC power output to the load, significantly improving the overall transmission efficiency and output stability of the system under complex operating conditions.

[0072] In an optional embodiment of the present invention, the capacitance value of the series compensation capacitor in the transmitting-side three-phase LCC compensation network is determined based on the resonant angular frequency of the three-phase magnetic field coupled wireless power transmission system, and the capacitance value of the series compensation capacitor in the receiving-side three-phase LCC compensation network is determined based on the resonant angular frequency of the three-phase magnetic field coupled wireless power transmission system.

[0073] Specifically, the expressions for the compensation capacitors in the transmitting-side three-phase LCC compensation network and the receiving-side three-phase LCC compensation network are given by equation (1): (1) Where ω is the system's resonant angular frequency; C Fi C is the compensation capacitor for the i-th phase on the transmitting side; Pi For the i-th phase on the transmitting side, it is the series compensation capacitor; C fk C is the compensation capacitor for the k-th phase on the receiving side; Sk L is the series compensation capacitor for the k-th phase on the receiving side; Fi L is the inductance of the i-th phase on the transmitting side; i Let be the series inductance of the i-th phase on the transmitting side; Lfk L is the inductance of the k-th phase on the receiving side; k Let i be the series inductance of the k-th phase on the receiving side; i represents the phase on the transmitting side, which can be A, B, or C; k represents the phase on the receiving side, which can be a, b, or c.

[0074] The expressions for the output current of the three-phase high-frequency inverter and the input current of the rectifier are calculated by equation (2): (2) Among them, M Aa M Bb M Cc These are the mutual inductance values ​​between the transmitting coils of phases A, B, and C and the receiving coils of phases a, b, and c, respectively. AI U BI U CI It is the square wave voltage output by the inverter, I A I B I C Ia, Ib, Ic: Current output by the three-phase high-frequency inverter; Ia, Ib, Ic: Current input to the rectifier. E This is an equivalent AC load. L FA 、L FB 、L FC This is the compensation inductor on the transmitting side. L fa 、L fb 、L fc This is the compensation inductance on the receiving side, where j is the imaginary unit.

[0075] It is related to DC power supply U D The relationship between them is shown in expression (3): (3) According to Kirchhoff's Voltage Law (KVL), the input voltage U can be listed. AI U BI U CI The loop relationship expression between phase currents is as follows: (4) (5) Among them, U AI U BI U CI This represents the square wave voltage output by the three-phase high-frequency inverter, with each phase differing by a phase angle of 120°. A I B I C Ia I b I c These represent the output current of phases A, B, and C of the inverter, and the equivalent load R flowing into the receiver, respectively. E The current; I PA I PB I PC I Sa I Sb I Sc These represent the phase currents on the six coils at the transmitting and receiving ends, respectively; where M Aa M Bb M Cc This represents the mutual inductance between in-phase units on the transmitting and receiving sides (phase A and phase a, phase B and phase b, phase C and phase c). j represents the imaginary unit, Z... Fi Z Pi Z CPi Z fk Z Sk Z Cfk Let each represent the equivalent reactance, as expressed by equation (6): (6) The resonance relationship of the LCC-LCC compensation network satisfies equation (7): (7) Substituting equation (7) into equations (4) and (5), we can obtain the expressions for the output current of the three-phase high-frequency inverter and the input current of the rectifier: (8) According to equation (8), the equivalent load R flowing into the receiver is... E Current I a I b I c Independent of load R E This means the system can achieve constant current output regardless of the load.

[0076] In this optional embodiment, the series compensation capacitor values ​​in the three-phase LCC compensation networks on the transmitting and receiving sides are calculated and determined based on the system's resonant angular frequency ω. This design method ensures that the compensation capacitors are precisely matched with the system's resonant frequency, thereby optimizing the system's power transmission efficiency and stability. By accurately calculating the compensation capacitor values, energy loss during transmission can be reduced, the system's power factor can be improved, and the system can maintain a stable operating state under various load conditions.

[0077] Combination Figure 6 As shown, Figure 6This diagram shows the phase current waveforms of each phase in a three-phase magnetic field-coupled wireless power transfer system under a 5Ω load. The upper half of the diagram shows the current waveforms on the transmitting side, and the lower half shows the current waveforms on the receiving side. Transmitting side (top): Shows the three-phase currents L... A L B L C These current waveforms change over time. They are sinusoidal, with a 120-degree phase difference, characteristic of a three-phase system. Each waveform has the same amplitude and frequency, indicating the system is operating in equilibrium. Receiver side (below): shows the three-phase current L on the receiver side. a L b L c These waveforms, which change over time, are also sinusoidal and correspond to the current waveform on the transmitting side, indicating that energy has been successfully transferred from the transmitting side to the receiving side. Combined with... Figure 6 It can be seen that the current waveform on the receiving side is similar to that on the transmitting side, but there is a certain phase difference. This is due to magnetic field coupling and natural phenomena in the energy transfer process. Furthermore, the current amplitude indicates the system's performance under a 5Ω load and can be used to evaluate the system's transmission efficiency and stability.

[0078] Combination Figure 7 As shown, Figure 7 The charging currents for loads of 5Ω, 10Ω, 15Ω, and 20Ω are given. As can be seen from the figure, the system output current fluctuates slightly as the load increases, with an overall relative fluctuation amplitude of 4%, demonstrating good constant current output characteristics.

[0079] Optionally, the air gap between the transmitting-side ferrite substrate and the receiving-side ferrite substrate is 120 mm.

[0080] Optionally, the transmitting-side ferrite substrate and the receiving-side ferrite substrate are made of TDK PC90 material.

[0081] Specifically, in this optional embodiment, referring to Table 2, the air gap between the transmitting-side ferrite substrate and the receiving-side ferrite substrate is set to 120 mm. An appropriate air gap helps optimize magnetic coupling efficiency, ensuring that the magnetic field generated on the transmitting side can be effectively coupled to the receiving side. The air gap also aids in heat dissipation, preventing the system from overheating during high-power transmission. Simultaneously, it provides the necessary physical space to reduce the risk of direct contact and improve system safety.

[0082] TDK PC90 was chosen as the ferrite substrate material due to its high permeability and low loss characteristics. Using TDK PC90 improves the efficiency of the magnetic coupler, reduces energy loss during transmission, and enhances system stability and reliability. The coil wire diameter is 4.76 mm. The wire diameter affects the coil's resistance and current carrying capacity; a thicker wire diameter helps reduce resistance loss and improves the system's power transmission efficiency. The magnetic coupler's outer diameter is 514.6 mm, determining the coil's physical dimensions and the possible number of turns. A larger outer diameter allows for a larger coil area, contributing to stronger magnetic coupling. The coil turn spacing is 3 mm, which helps reduce internal capacitance effects, thus improving system stability. Appropriate turn spacing reduces electromagnetic interference between coils, improving the magnetic coupler's performance. Each Q-type coil consists of 8 turns of wire. It should be noted that the Q-type coil is a common coil structure used to improve self-inductance and reduce distributed capacitance. The choice of 8 turns is based on optimization of coil self-inductance and mutual inductance to achieve optimal magnetic coupling performance.

[0083] Table 2 Parameters related to magnetic couplers

[0084] In general, combining Figure 1 As shown, the DC power supply in this embodiment U D Provides energy to the system, capacitor C D Used for filtering DC power supplies and reducing power ripple; the three-phase high-frequency inverter consists of six MOSFET switches. Q 1 to Q It consists of 6 components, converting direct current into three-phase alternating current; inductor L FA , L FB , L FC Together with the MOSFET switch, it forms a resonant circuit to generate high-frequency alternating current; capacitor C PA , C PB , C PC With inductance L FA , L FB , L FC A three-phase LCC compensation network is constructed on the transmitting side to adjust the system's resonant frequency and improve the power factor; transmitting coil L A , L B ,L C Generate a high-frequency magnetic field, through mutual inductance M Aa , M Bb , M Cc Coupled with the receiving coil, wireless power transmission is achieved; the receiving coil L a , L b , L c Capacitor receives the coupled high-frequency magnetic field energy. C SA , C SB , C SC Together with the receiving coil, they form a three-phase LCC compensation network on the receiving side to adjust the resonant frequency on the receiving side; the full-bridge rectifier consists of diodes. D 1 to D It consists of 6 components, converting the received high-frequency alternating current into direct current; and a filter capacitor. C F Smooth the rectified DC power to reduce voltage ripple; ultimately, reduce battery load. R B It receives DC power, completing the reception and utilization of energy. The entire system achieves efficient and stable wireless power transmission through precise component selection and parameter matching.

[0085] Figure 2 This is the equivalent circuit diagram of a three-phase magnetic field-coupled wireless power transfer system. Figure 1 The physical components are abstracted into circuit models, where U AI , U BI , U CI These represent the voltage sources output by the three-phase inverter. I A , I B , I C It is the three-phase current on the transmitting side, passing through the inductor. L FA , L FB , L FC and capacitor C PA , C PB , C PCAfter adjustment, the three-phase LCC compensation network is connected to the transmitting coil. L A , L B , L C Connected, through mutual induction jωM Aa , jωM Bb , jωM Cc With the receiving coil on the receiving side L a , L b , L c Coupling, the current in the receiving coil is I a , I b , I c After passing through the filter capacitor C SA , C SB , C SC and inductor L Sa , L Sb , L Sc After constructing the receiving-side three-phase LCC compensation network, through impedance Z fa , Z fb , Z fc to equivalent AC load R E Power supply: The equivalent circuit diagram in this embodiment illustrates the energy transfer process from the transmitting side to the receiving side, including key components such as resonance, coupling, rectification, and filtering.

[0086] The present invention also provides a three-phase magnetic field coupled wireless power transmission system, including a transmitting part and a receiving part; The transmitting section includes a DC voltage source, a three-phase high-frequency inverter, and a transmitter-side three-phase LCC compensation network. The DC voltage source is connected to the input terminal of the three-phase high-frequency inverter, and the output terminal of the three-phase high-frequency inverter is connected to the input terminal of the transmitter-side three-phase LCC compensation network. The transmitter-side three-phase LCC compensation network includes three resonant units. Each resonant unit includes a series compensation capacitor and a transmitting coil. The series compensation capacitor and the transmitting coil are connected in series to form a series branch. The three series branches are connected in a Y-type manner to form a transmitter-side resonant circuit. The receiving section includes a receiving-side three-phase LCC compensation network and a rectifier-filter unit. The receiving-side three-phase LCC compensation network includes three resonant units, each of which includes a series compensation capacitor and a receiving coil. The series compensation capacitor and the receiving coil are connected in series to form a series branch, and the three series branches are connected in a Y-type manner to form a receiving-side resonant circuit. The output terminal of the receiving-side resonant circuit is connected to the input terminal of the rectifier-filter unit, and the output terminal of the rectifier-filter unit is used to supply power to the load. The three transmitting coils and the three receiving coils all adopt a double-layer overlapping structure, and the distance between each transmitting coil and the corresponding ferrite is equal, and the distance between each receiving coil and the corresponding ferrite is equal. Among the three transmitting coils, the first transmitting coil and the third transmitting coil are both composed of two Q-type coils with opposite magnetic field directions connected diagonally in series, and the second transmitting coil is composed of two Q-type coils with the same magnetic field direction connected vertically in series. The structural arrangement of the receiving coils is geometrically symmetrical with that of the transmitting coils.

[0087] This embodiment of the three-phase magnetic field-coupled wireless power transmission system employs a double-layer overlapping structure for both the transmitting and receiving coils, with each coil equidistant from the ferrite core. This structural design ensures consistent distance between each coil and the ferrite core, thereby maintaining a physical balance between the self-inductance and mutual inductance of each coil. Due to this balance of inductance and mutual inductance, the current in each phase of the three-phase system is more uniform, reducing losses caused by current imbalance. Furthermore, the double-layer overlapping structure reduces uneven magnetic field distribution caused by unequal distances, thereby reducing eddy current losses and further improving the system's transmission efficiency.

[0088] Meanwhile, the geometrically symmetrical coil arrangement further ensures the balance of inductance and mutual inductance, making the current in each phase of the three-phase system more uniform and reducing losses caused by current imbalance. Furthermore, this symmetry eliminates interphase mutual inductance between coils on the same side and cross-coupling between coils on different sides, resulting in only three pairs of main coupled magnetic circuits in the entire system, significantly simplifying the complexity of system design. By reducing unnecessary coupling relationships, the system can utilize the magnetic field more efficiently during transmission, reducing energy waste.

[0089] LCC compensation networks reduce reflection loss and improve system transmission efficiency by optimizing resonant frequency and impedance matching. Properly configured compensation capacitors enable better impedance matching at high frequencies, reducing reflection loss caused by impedance mismatch.

[0090] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A three-phase magnetic field coupled wireless power transfer system, characterized by, The transmitting part is used for coupling with the receiving part, The transmitting part comprises a direct current voltage source, a three-phase high-frequency inverter and a transmitting-side three-phase LCC compensation network; the direct current voltage source is connected to an input end of the three-phase high-frequency inverter, an output end of the three-phase high-frequency inverter is connected to an input end of the transmitting-side three-phase LCC compensation network, and the transmitting-side three-phase LCC compensation network comprises three resonance units, each of which comprises a series compensation capacitor and a transmitting coil; the series compensation capacitor and the transmitting coil are connected in series to form a series branch, and the three series branches are connected in a Y type to form a transmitting-side resonance loop. Each of the three transmitting coils adopts a double-layer overlapping structure, and the distance between each transmitting coil and the corresponding ferrite is equal; among the three transmitting coils, the first transmitting coil and the third transmitting coil are each composed of two Q-type coils with opposite magnetic field directions and are connected in series at opposite angles, and the second transmitting coil is composed of two Q-type coils with the same magnetic field direction and are connected in series one above the other.

2. The three-phase magnetic field coupled wireless power transfer system of claim 1, wherein, The transmitting-side three-phase LCC compensation network further comprises three parallel compensation capacitors and three compensation inductors. In the transmitting-side three-phase LCC compensation network, one end of each parallel compensation capacitor is connected to a connection point between the series compensation capacitor and the compensation inductor in the corresponding series branch, and the other end of each parallel compensation capacitor is connected together to form a common end; the other end of each compensation inductor is connected to the midpoint of each bridge arm in the three-phase high-frequency inverter.

3. The three-phase magnetic field coupled wireless power transfer system of claim 1, wherein, The transmitting coil is arranged on a transmitting-side ferrite substrate, The distance between each part of the transmitting coil and the transmitting-side ferrite substrate is equal.

4. The three-phase magnetic field coupled wireless power transfer system of claim 3, wherein, Each transmitting coil comprises a first sub-coil and a second sub-coil, and the transmitting-side ferrite substrate, the second sub-coil and the first sub-coil are arranged in a stacked manner.

5. The three-phase magnetic field coupled wireless power transfer system of claim 1, wherein, The three-phase high-frequency inverter is a circuit topology composed of six MOSFET switch tubes in a three-phase full-bridge manner. The three-phase high-frequency inverter is used to control the three-phase alternating current flowing through the three transmitting coils to have a phase difference of 120 degrees.

6. A three-phase magnetic field coupled wireless power transfer system, characterized by, The receiving part is used for coupling with the transmitting part, The receiving part comprises a receiving-side three-phase LCC compensation network and a rectifier filter unit; the receiving-side three-phase LCC compensation network comprises three resonance units, each of which comprises a series compensation capacitor and a receiving coil; the series compensation capacitor and the receiving coil are connected in series to form a series branch, and the three series branches are connected in a Y type to form a receiving-side resonance loop; an output end of the receiving-side resonance loop is connected to an input end of the rectifier filter unit, and an output end of the rectifier filter unit is used to supply power to a load; Each of the three receiving coils adopts a double-layer overlapping structure, and the distance between each receiving coil and the corresponding ferrite is equal; the structure and arrangement of the receiving coil are geometrically symmetrical with the transmitting coil of the transmitting part.

7. The three-phase magnetic field coupled wireless power transfer system of claim 6, wherein, The receiving-side three-phase LCC compensation network further comprises three parallel compensation capacitors and three compensation inductors. One end of each parallel compensation capacitor is connected to the connection point of the series compensation capacitor and the compensation inductor in the corresponding series branch, and the other end of each parallel compensation capacitor is connected together to form a common terminal; the other end of each compensation inductor is connected to the midpoint of each bridge arm in the rectifier filter unit; The rectifier filter unit comprises a three-phase rectifier formed by six diodes in a full-bridge manner and a filter capacitor connected in parallel with the load.

8. The three-phase magnetic field coupled wireless power transfer system of claim 7, wherein, The receiving coils are arranged on a receiving side ferrite substrate. The distance between each part of the receiving coils and the receiving side ferrite substrate is equal.

9. The three-phase magnetic field coupled wireless power transfer system of claim 8, wherein, Each receiving coil comprises a third sub-coil and a fourth sub-coil, and the receiving side ferrite substrate, the fourth sub-coil and the third sub-coil are arranged in sequence.

10. The three-phase magnetic field coupled wireless power transfer system of claim 7, wherein, There is no magnetic coupling interference between any of the receiving coils and any of the transmitting coils of different phases in the transmitting part. Three main coupling energy transmission channels are formed between the three receiving coils and the three transmitting coils, wherein the three main coupling energy transmission channels are a first coupling channel formed by the first receiving coil and the corresponding transmitting coil, a second coupling channel formed by the second receiving coil and the corresponding transmitting coil, and a third coupling channel formed by the third receiving coil and the corresponding transmitting coil.

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