An omni-directional wireless power transfer device with a semi-open transmit coil

Abstract

The application discloses an omnidirectional wireless power transmission device with a semi-open transmitting coil and belongs to the technical field of wireless power transmission. The device comprises a transmitting end and a receiving end. The transmitting end is composed of multiple groups of electrically isolated transmitting coil units to form a semi-open cuboid frame, and an accommodating cavity is formed in the interior; a three-phase full-bridge inverter circuit is connected with the transmitting coil through a primary side resonance compensation circuit, and a uniformly rotating magnetic field in all directions is generated in a three-dimensional effective charging area by adjusting the phase distribution of the coil current. The receiving end comprises a receiving coil which can be completely placed in the accommodating cavity, a secondary side resonance compensation circuit and a rectification and filtering circuit. The application generates a spatially uniform rotating magnetic field in the transmitting coil and the effective area through a semi-open orthogonal frame structure and a three-phase alternating excitation with controllable phase, overcomes the sensitivity of a traditional three-dimensional coil to the position and angle of the receiving end, and significantly improves the freedom, flexibility and magnetic field utilization rate of the spatial omnidirectional wireless power transmission.

Description

Technical Field

[0001] This invention relates to the field of wireless power transmission technology, and in particular to an omnidirectional wireless power transmission device with a semi-open transmitting coil. Background Technology

[0002] Wireless power transfer (WPT) is a power supply technology that uses an invisible, soft medium in space (such as magnetic fields, electrical energy, microwaves, etc.) to transfer electrical energy from the power source to the power consumer.

[0003] Based on the principles of power transmission, wireless power delivery (WPT) technology can be broadly categorized into three types: The first type is electromagnetic radiation, primarily including microwave and laser methods. Its advantages lie in its high transmission power and transmission distance, which is far greater than the geometric dimensions of the transmitting device. However, the energy transmission direction is unidirectional and it has a significant impact on organisms and the environment. The second type is electromagnetic induction, based on the principle of electromagnetic induction. This method has high transmission efficiency but is only suitable for short-range applications. The third type is magnetic resonance, based on the principles of electromagnetic induction and resonance. By setting the parameters of the transmitting and receiving coils, the system operates at the same resonant frequency, offering advantages such as high transmission efficiency, high transmission power, and long transmission distance. Freeing researchers from the constraints of wires and achieving wireless power supply has been a long-standing goal.

[0004] Traditional wireless power transfer (WPT) systems use magnetic couplers consisting of a single transmitting coil and a single receiving coil. While the coil structure is simple and easy to manufacture, it only generates magnetic flux in a fixed direction, thus limiting the receiver's free positioning and mobility. To address these issues, researchers have recently focused on omnidirectional WPT technology, aiming to overcome the shortcomings of existing wireless power transfer technologies, such as limited transmission angle, short transmission range, and weak anti-offset capability.

[0005] The prior art proposes a spherical orthogonal transmitting coil structure, in which three coils provide magnetic fields in the X, Y, and Z directions respectively, and the omnidirectional magnetic field is synthesized by vector synthesis. However, it is a closed structure, which means that only the external magnetic field can be used during charging, and the stronger internal magnetic field is abandoned, resulting in low magnetic field utilization. Moreover, this structure does not add additional control to the current excitation and cannot generate a rotating magnetic field.

[0006] The prior art proposes a cuboid orthogonal coil structure, which includes three mutually orthogonal and independent transmitting coils. When different excitation currents are passed through the transmitting coils, an omnidirectional magnetic field is generated in space. However, it is still a closed structure, which abandons the strong magnetic field inside the coil and has low magnetic field utilization. Summary of the Invention

[0007] This invention aims to at least improve upon the problems existing in the prior art, such as drastic fluctuations in transmission characteristics caused by changes in receiver position and angle, unstable received power, and low magnetic field utilization. It proposes an omnidirectional wireless power transmission device with a semi-open transmitting coil, enabling stable power supply to the receiver at any position and angle within the three-dimensional space enclosed by the transmitting coil, thereby improving magnetic field utilization.

[0008] The technical solution of the present invention is as follows: An omnidirectional wireless power transmission device with a semi-open transmitting coil includes a transmitting end and a receiving end, wherein the transmitting end includes: Multiple sets of transmitting coil units are electrically isolated from each other and enclose a semi-open cuboid frame, with each set of transmitting coil units forming at least one face of the cuboid frame, and the cuboid frame having a cavity. A three-phase full-bridge inverter circuit is used to provide three-phase alternating current to the transmitting coil. The three-phase full-bridge inverter circuit is connected to a DC power supply to power the three-phase full-bridge inverter circuit. The primary-side resonant compensation circuit is connected between the three-phase full-bridge inverter circuit and the transmitting coil. The three-phase full-bridge inverter circuit adjusts the current phase distribution of each transmitting coil in the transmitting coil unit, generating a uniform rotating magnetic field in all directions within the three-dimensional effective charging area, ensuring that the receiving end can stably receive electrical energy at any position within the effective area. The receiving end includes: The receiving coil can be completely placed inside the cavity; A secondary resonant compensation circuit is connected to the receiving coil; The rectifier and filter circuit is connected to the secondary resonant compensation circuit.

[0009] In one possible technical solution, the transmitting coil unit further includes: Two first transmitting coils are aligned to form the two sides of the cuboid frame and connected in series to form a first transmitting coil unit. Two second transmitting coils are arranged adjacent to and orthogonal to the first transmitting coil, and are connected in series to form a second transmitting coil unit; The third transmitting coil has multiple square coils connected in series to form the third transmitting coil unit, which serves as the bottom surface of the cuboid frame. It can generate a vertical magnetic field inside the transmitting coil cavity, thereby increasing the energy transmission coverage of the coil.

[0010] In one possible technical solution, the first transmitting coil and the second transmitting coil have the same structure, both being rectangular coils with the long side being twice the width. This arrangement can adapt to the side dimensions of the cuboid frame, making the direction of the magnetic field generated by the coil more consistent with the direction of the magnetic field at the energy receiving end, thereby improving the coupling coefficient. At the same time, a reasonable aspect ratio can reduce the space occupied by the coil, balancing energy transmission efficiency and structural compactness.

[0011] In one possible technical solution, the square coil further comprises: The first coil is located on the bottom contour of the cuboid frame; Two second coils are placed parallel to the first coil, connected in series, and then connected to the first coil to achieve basic magnetic field coverage.

[0012] In one possible technical solution, the two second coils are further arranged symmetrically along the diagonal of the first coil.

[0013] In one possible technical solution, the side length of each second coil is half the side length of the first coil, which enables the magnetic field range of the second coil to complement that of the first coil, avoiding magnetic field waste. At the same time, a reasonable size ratio can optimize the equivalent resistance of the coil and further improve energy transmission efficiency.

[0014] In one possible technical solution, the excitation currents of the two first transmitting coils constituting the first transmitting coil unit are in the same direction; The excitation currents of the two second transmitting coils that make up the second transmitting coil unit are in the same direction; The two second coils that make up the third transmitting coil unit have currents in opposite directions. This arrangement allows the magnetic fields generated by the two second coils to be superimposed in opposite directions, further optimizing the uniformity of the magnetic field. At the same time, the reverse current can reduce the mutual inductance loss between the coils and improve the efficiency of energy transmission.

[0015] In one possible technical solution, the three-phase full-bridge inverter circuit is further divided into three, which are respectively connected to three transmitting coil units. Each three-phase full-bridge inverter circuit can independently output high-frequency alternating current to drive the corresponding transmitting coil unit to generate an alternating magnetic field.

[0016] In one possible technical solution, further, the three-phase current of the three-phase full-bridge inverter circuit... i A , i B , i CWith the amplitude and frequency being the same, this setting ensures the balance of the three-phase current, making the high-frequency alternating current output by the inverter circuit more stable. This, in turn, ensures that the alternating magnetic field strength generated by the transmitting coil unit is uniform and the frequency is stable, avoiding magnetic field disturbances caused by differences in current amplitude or frequency, and reducing energy transmission loss.

[0017] In one possible technical solution, the phase relationship of the three-phase currents is further defined as follows: the initial phase of the first phase current is 0. ° The initial phase of the second phase current is 180°. ° The initial phase of the third phase current is 90°. ° This configuration allows the alternating magnetic fields generated by the three transmitting coil units to work synergistically, creating a uniform rotating magnetic field space to achieve omnidirectional performance.

[0018] The omnidirectional wireless power transmission device with a semi-open transmitting coil according to the present invention has the following beneficial effects: 1. The semi-open transmitting coils of the present invention are arranged into an orthogonal cuboid frame structure, which can form a magnetic field covering the inside of the coil. When the receiving coil is in different positions and angles inside the transmitting coil, the current excitation phase of the three transmitting coils supplied to the three-dimensional transmitting coil is adjusted by the three-phase full-bridge inverter circuit, so that the three transmitting coils can generate a omnidirectional spatial uniform rotating magnetic field, so that the receiving coil can receive energy at any position and angle within the effective range of the transmitting coil.

[0019] 2. The three-dimensional transmitting coil structure of the present invention overcomes the limitations of transmission direction sensitivity and low magnetic field utilization of existing three-dimensional coil structures, and meets the requirements of high degree of freedom and high flexibility of receiving coil in spatial position.

[0020] 3. Compared with traditional three-dimensional transmitting coils, this invention can meet the requirements of transmission direction sensitivity, the magnetic field distribution is more uniform on all observation surfaces, and the magnetic field utilization rate is improved, making it more suitable for omnidirectional wireless power transmission in space.

[0021] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1This is a schematic diagram of the transmitting coil and receiving coil of the omnidirectional wireless power transmission device of the present invention; Figure 2 This is a schematic diagram of the structural connections of the first transmitting coil of the present invention; Figure 3 This is a schematic diagram of the structural connections of the second transmitting coil of the present invention; Figure 4 This is a schematic diagram of the structural connections of the third transmitting coil of the present invention; Figure 5 This is an equivalent circuit diagram of the omnidirectional wireless power transmission device of the present invention; Figure 6 This is a schematic diagram of the waveform generated by the switch controlled by the switch waveforms with the same operating frequency but different phases in this invention. Figure 7 This is a simplified equivalent circuit diagram of the omnidirectional wireless power transmission device of the present invention; Figure 8 The simulated magnetic field distribution diagrams for the three transmitting coils of this invention, with initial phases of 0°, 180°, and 90°, at ωt=0° and 45°; Figure 9 The simulated magnetic field distribution diagrams for the three transmitting coils of this invention, with initial phases of 0°, 180°, and 90°, at ωt=90° and 135°; Figure 10 The simulated magnetic field distribution diagrams for the three transmitting coils of this invention, with initial phases of 0°, 180°, and 90°, at ωt=180° and 225°; Figure 11 The simulated magnetic field distribution diagrams for the three transmitting coils of this invention, with initial phases of 0°, 180°, and 90°, at ωt=270° and 315°; Figure 12 A schematic diagram showing the receiving coil rotating around its center along the X, Y, and Z axes by angles α, β, and γ; Figure 13 The graph shows the load voltage variation curves when the receiving coil rotates around its center X, Y, and Z axes, with the receiving coil inside the three-dimensional omnidirectional transmitting coil and the center point of the receiving coil coinciding with the center point of the three-dimensional transmitting coil. Figure 14 This is a schematic diagram of the receiving coil at different points within the three-dimensional transmitting coil in this invention; Figure 15 This is a graph showing the load voltage change when the receiving coil is at point E inside the transmitting coil and the receiving coil rotates around its center X, Y, and Z axes by angles α, β, and γ, respectively. Figure 16This is a graph showing the load voltage change when the receiving coil is at point F inside the transmitting coil and the receiving coil rotates around its center X, Y, and Z axes by angles α, β, and γ, respectively. Figure 17 This is a graph showing the load voltage change when the receiving coil is at point G inside the transmitting coil and rotates around its center X, Y, and Z axes by angles α, β, and γ, respectively. Figure 18 This is a graph showing the load voltage change when the receiving coil is at point H inside the transmitting coil and the receiving coil rotates around its center X, Y, and Z axes by angles α, β, and γ, respectively.

[0024] Figure label: First transmitting coil 1, second transmitting coil 2, third transmitting coil 3, first coil 31, second coil 32, receiving coil 4. Detailed Implementation

[0025] The embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0026] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0028] The terms "first," "second," "third," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects and not to describe a particular order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, it may include a series of steps or units, or optionally, steps or units not listed, or other steps or units inherent to these processes, methods, products, or devices.

[0029] The accompanying drawings show only the portions relevant to this application, not all of them. Before discussing exemplary embodiments in more detail, it should be noted that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe operations (or steps) as sequential processes, many of these operations may be performed in parallel, concurrently, or simultaneously. Furthermore, the order of the operations may be rearranged. The process may be terminated when its operation is completed, but may also have additional steps not included in the drawings. The process may correspond to a method, function, procedure, subroutine, subprogram, etc.

[0030] The terms “component,” “module,” “system,” “unit,” etc., used in this specification are used to refer to computer-related entities, hardware, firmware, combinations of hardware and software, software, or software in execution. For example, a unit can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, a thread of execution, a program, and / or distributed between two or more computers. Furthermore, these units can be executed from various computer-readable media on which various data structures are stored. Units can communicate, for example, via local and / or remote processes based on signals having one or more data packets (e.g., data from a second unit interacting with another unit between a local system, a distributed system, and / or a network; for example, the Internet interacting with other systems via signals).

[0031] Example like Figures 1 to 4 As shown, this embodiment provides an omnidirectional wireless power transmission device with a semi-open transmitting coil, including a transmitting end and a receiving end, wherein the transmitting end includes: Three sets of transmitting coil units, electrically isolated from each other, are arranged to form a semi-open cuboid frame, with each set of transmitting coil units constituting at least one face of the cuboid frame. The cuboid frame has a cavity, wherein the transmitting coil units include: Two first transmitting coils 1 are aligned to form the two sides of the cuboid frame and connected in series to form a first transmitting coil unit. Two second transmitting coils 2 are arranged adjacent to and orthogonal to the first transmitting coil 1, and are connected in series to form a second transmitting coil unit; The third transmitting coil 3 has multiple square coils connected in series to form the third transmitting coil unit, which serves as the bottom surface of the cuboid frame, as shown below. Figure 1 As shown, the origin of the coordinate system is the center of the cuboid frame; A three-phase full-bridge inverter circuit is used to provide three-phase alternating current to the transmitting coil. The three-phase full-bridge inverter circuit is connected to a DC power supply to power the three-phase full-bridge inverter circuit. There are three three-phase full-bridge inverter circuits, which are respectively connected to three transmitting coil units.

[0032] The primary-side resonant compensation circuit is connected between the three-phase full-bridge inverter circuit and the transmitting coil. The three-phase full-bridge inverter circuit adjusts the current phase distribution of each transmitting coil in the transmitting coil unit, generating a uniform rotating magnetic field in all directions within the three-dimensional effective charging area, ensuring that the receiving end can stably receive electrical energy at any position within the effective area. The receiving end includes: The receiving coil 4 can be completely placed inside the cavity; The secondary-side resonant compensation circuit is connected to the receiving coil 4; The rectifier and filter circuit is connected to the secondary resonant compensation circuit.

[0033] It should be noted that in this embodiment, the first transmitting coil 1 and the second transmitting coil 2 have the same structure, size, and number of turns; both are rectangular coils with a long side dimension of [missing information]. a It is twice the width of the side, and the distance between the two rectangular coils is... a Both are perpendicular to the bottom surface, and together they form the side structure of an orthogonal cuboid.

[0034] It should be noted that, in this embodiment, the square coil includes: The first coil 31 is located on the bottom contour of the cuboid frame, and its side length is... a Specifically, in this embodiment, the four corners of the first coil 31 coincide with the four corners of the bottom square of the cuboid frame, forming a semi-open structure.

[0035] Two second coils 32 are placed parallel to the first coil 31, symmetrically distributed along the diagonal of the first coil 31, connected in series and then connected to the first coil 31. Their side length is... a / 2.

[0036] It should be noted that, in this embodiment, the excitation currents of the three transmitting coil units meet the requirements of "same amplitude, same frequency, and specific phase difference," specifically: The excitation current of the two first transmitting coils 1 that make up the first transmitting coil unit i A Same size and orientation, such as Figure 2 As shown; The excitation current of the two second transmitting coils 2 that make up the second transmitting coil unit i B Same size and orientation, such as Figure 3 As shown; The excitation current of the three square coils that make up the third transmitting coil unit i CThey are of the same size, wherein the current direction of the first coil 31 and the second coil 32 is the same, and the current direction of the other second coil 32 is opposite, such as... Figure 4 As shown.

[0037] It should be noted that in this embodiment, the current amplitude of the three input transmitting coil units is the same, which is: , Where ω is the operating angular frequency. I m Let i be the current amplitude, i = 1, 2, 3; n = A, B, C.

[0038] The time-varying expressions for the three-phase alternating excitation currents in the three transmitting coils are as follows: , in I m is the current amplitude, and ω is the operating angular frequency. t For time, ψ A , ψ B , ψ C The initial phases of the excitation currents for the three transmitting coils are 0°, 180°, and 90°, respectively.

[0039] To ensure that the excitation current satisfies the above phase relationship, the specific structure of the three-phase full-bridge inverter circuit is as follows: Figure 5 As shown, it includes: At the system's transmitting end, the same DC power supply V is used. in The first phase inverter circuit, connected in parallel with three full-bridge inverter circuits, includes four switching transistors S. A1 S A2 S A3 S A4 The second-phase inverter circuit includes four switching transistors S. B1 S B2 S B3 S B4 The third-phase inverter circuit includes four switching transistors S. C1 S C2 S C3 S C4 Switches are controlled using switching waveforms with the same operating frequency but different phases to generate the desired waveform, such as... Figure 6 As shown.

[0040] In the first phase inverter circuit, the DC power supply V in The positive terminals are respectively connected to the switching transistor S A1 S A3 One end is connected to the DC power supply V. inThe negative terminals are respectively connected to the switching transistor S A2 S A4 One end is connected; the switching transistor S A1 S A2 The other end is connected to the compensation inductor L1 in the first path of the primary-side resonant compensation circuit. The series capacitor C1 in the first path of the primary-side resonant compensation circuit is connected to one end of the first transmitting coil 1. The other end of the first transmitting coil 1 is connected to the capacitor Cp1 in the first path of the primary-side resonant compensation circuit and the switching transistor S. A3 S A4 One end is connected.

[0041] In the second phase inverter circuit, the DC power supply V in The positive terminals are respectively connected to the switching transistor S B1 S B3 One end is connected to the DC power supply V. in The negative terminals are respectively connected to the switching transistor S B2 S B4 One end is connected; the switching transistor S B1 S B2 The other end is connected to the compensation inductor L2 in the second path of the primary-side resonant compensation circuit. The series capacitor C2 in the second path of the primary-side resonant compensation circuit is connected to one end of the second transmitting coil 2. The other end of the second transmitting coil 2 is connected to the capacitor Cp2 in the second path of the primary-side resonant compensation circuit and the switching transistor S. B3 S B4 One end is connected.

[0042] In the third-phase inverter circuit, the DC power supply V in The positive terminals are respectively connected to the switching transistor S C1 S C3 One end is connected to the DC power supply V. in The negative terminals are respectively connected to the switching transistor S C2 S C4 One end is connected; the switching transistor S C1 S C2 The other end is connected to the compensation inductor L3 in the third path of the primary-side resonant compensation circuit. The series capacitor C3 in the third path of the primary-side resonant compensation circuit is connected to one end of the third transmitting coil 3. The other end of the third transmitting coil 3 is connected to the capacitor Cp3 in the third path of the primary-side resonant compensation circuit and the switching transistor S. C3 S C4 One end is connected.

[0043] It should be noted that, in this embodiment, the primary-side resonant compensation circuit can adopt an LCC-S type or other equivalent resonant compensation network. The specific parameters of the LCC-S type compensation network are as follows: The primary-side resonant compensation circuit is an LCC topology, with the transmitting coil inductances being L... A LB L C Each corresponds to one compensation circuit (compensation inductors L1~L3, series capacitors C1~C3, parallel capacitor C...). p1 ~C p3 Its resonance condition is: Where ω is the operating angular frequency, i=1,2,3; n=A,B,C.

[0044] The receiver uses a series topology, and the inductance of the receiving coil is L. S With secondary side compensation capacitor C S In series, the resonance condition is: .

[0045] It should be noted that in this embodiment, the receiving coil 4 is a square, circular, or rectangular coil, which needs to be able to fit completely inside the cavity.

[0046] The rectifier and filter circuit includes a full-bridge rectifier (diodes D1~D4) and a filter capacitor C. f .

[0047] Receiver coil inductance L S With compensation capacitor C S Series connection; compensation capacitor C S One end is connected to the anode of diode D1 in the full-bridge rectifier; the receiving coil inductance L S One end of diode D1 is connected to the cathode of diode D4 in the full-bridge rectifier; the cathode of diode D1 is also connected to the cathode of diode D2 and the filter capacitor C. f One end of the diode is connected to the load resistor R; the anode of diode D3 is also connected to the anode of diode D4, the other end of the filter capacitor Cf, and the other end of the load resistor R; the anode of diode D1 is connected to the anode of diode D3, and the anode of diode D2 is also connected to the anode of diode D4.

[0048] This embodiment provides the following specific implementation examples to verify the beneficial effects of the present invention, and the specific parameters are as follows: DC power supply V in =120V, operating frequency f=100kHz.

[0049] The three-dimensional transmitting coil consists of three transmitting coil units: the first transmitting coil unit is as follows: Figure 2 As shown, it consists of two identical first transmitting coils 1 connected in series, with current flowing in the same direction and of equal magnitude. The length of the first transmitting coil 1 is... a =240mm, width is a / 2=120mm, number of turns=8, the distance between the two first transmitting coils 1 is equal to the length of the coil, which is 240mm, inductance L A =123.1μH.

[0050] The second transmitting coil unit is as follows: Figure 3 As shown, its structure is exactly the same as the first transmitting coil unit, wherein the currents in the two second transmitting coils 2 are in the same direction and equal in magnitude, and the inductance L B =123μH.

[0051] The first transmitting coil 1 and the second transmitting coil 2 are placed orthogonally to form a cuboid structure.

[0052] The third transmitting coil 3 is a composite coil, such as... Figure 4 As shown, the side with length is placed on the bottom surface. a A large square coil with a diameter of 240mm and two sides with a length of... a It is composed of small square coils with a diameter of 120mm connected in series, with 8 turns and a total inductance L. C =184.3μH. The current in its three square coils is the same, with the current in the large square coil and the small square coil in the same direction, and the current in the other small square coil in the opposite direction.

[0053] The receiving coil is a square receiving coil 4 with a side length of 60mm and 10 turns, and an inductance L. S =34.8μH.

[0054] DC power supply V in The three-phase inverter circuit is simplified to a three-phase AC input voltage source U A U B U C By treating the full-bridge rectifier circuit and load at the receiving end as equivalent resistors, the simplified equivalent circuit can be obtained as follows: Figure 7 As shown, where M A M B M C These are the mutual inductance values ​​between the first transmitting coil 1, the second transmitting coil 2, the third transmitting coil 3, and the receiving coil 4, respectively.

[0055] in, , , .

[0056] The resonance compensation parameters are: Primary side first phase: L1 = 21.5 μH, C1 = 25 nF, C p1 =118nF; Second phase on the primary side: L2 = 21.5 μH, C2 = 25 nF, C p2 =118nF; Primary-side third phase: L3 = 36.9 μH, C3 = 17.2 nF, C p3 =68nF; Secondary side: C S =72.8nF.

[0057] DC power supply V in Powering a three-phase full-bridge inverter circuit, by controlling the switching transistors in the three-phase full-bridge inverter circuit, a rotating uniform magnetic field can be generated in space when three-phase alternating current is applied to the three transmitting coils for excitation.

[0058] Figure 8 This is a simulated magnetic field distribution diagram of the three transmitting coils in the three-dimensional transmitting coil of the present invention, with initial phases of currents of 0°, 180°, and 90°, at ωt=0° and 45°. Figure 8 (a) in the figure is a simulated magnetic field distribution at ωt=0°. Figure 8 (b) is a simulated magnetic field distribution diagram at ωt=45°. From left to right, they are the front view, side view and top view of the magnetic field distribution respectively. It can be seen from the figure that at different times of the current cycle, the direction of the magnetic field vector inside the cavity of the transmitting coil rotates with time, and the magnetic field intensity distribution inside the cavity is relatively uniform.

[0059] Figure 9 This is a simulated magnetic field distribution diagram of the three transmitting coils in the three-dimensional transmitting coil of the present invention, with initial current phases of 0°, 180°, and 90°, at ωt=90° and 135°. Figure 9 (c) in the figure shows the simulated magnetic field distribution at ωt=90°. Figure 9 (d) in the figure is a simulated magnetic field distribution diagram at ωt=135°. From left to right, they are the front view, side view and top view respectively. It can be seen from the figure that at different times of the current cycle, the direction of the magnetic field vector inside the cavity of the transmitting coil rotates with time, and the magnetic field intensity distribution inside the cavity is relatively uniform.

[0060] Figure 10 This is a simulated magnetic field distribution diagram of the three transmitting coils in the three-dimensional transmitting coil of the present invention, with initial current phases of 0°, 180°, and 90°, at ωt=180° and 225°. Figure 10 (e) in the figure is the simulated magnetic field distribution at ωt=180°. Figure 10 (f) in the figure is a simulation distribution diagram of the magnetic field at ωt=225°. From left to right, they are the front view, side view and top view respectively. It can be seen from the figure that at different times of the current cycle, the direction of the magnetic field vector inside the cavity of the transmitting coil rotates with time, and the magnetic field intensity distribution inside the cavity is relatively uniform.

[0061] Figure 11 This is a simulated magnetic field distribution diagram of the three transmitting coils in the three-dimensional transmitting coil of the present invention, with initial phases of currents of 0°, 180°, and 90°, at ωt=270° and 315°. Figure 11 (g) in the figure represents the simulated magnetic field distribution at ωt=270°. Figure 11 (h) is the magnetic field simulation distribution diagram at ωt=315°. From left to right, they are the front view, side view and top view respectively. It can be seen from the figure that at different times of the current cycle, the direction of the magnetic field vector inside the cavity of the transmitting coil rotates with time, and the magnetic field intensity distribution inside the cavity is relatively uniform.

[0062] Figure 13 When the receiving coil 4 is inside the three-dimensional omnidirectional transmitting coil, and the center point of the receiving coil 4 coincides with the center point of the cuboid transmitting coil, the receiving coil 4... Figure 12 The curves showing the change in the received voltage amplitude of the load when the load is rotated by angles α, β, and γ around the center of the receiving coil 4 along the X, Y, and Z axes, respectively.

[0063] If the two center points do not coincide, establish a coordinate system with the center point of the cuboid transmitting coil as the origin. The receiving coil 4 is located at four points inside the transmitting coil: E (-60mm, 60mm, 60mm), F (60mm, -60mm, 60mm), G (-60mm, 60mm, 80mm), and H (60mm, 60mm, 80mm). Figure 14 As shown, receiving coil 4 is... Figure 9 When the load receiving voltage changes as shown by rotating the receiver coil 4 around the X, Y, and Z axes by angles α, β, and γ, respectively, it is as follows: Figures 15-18 As shown, from Figures 15-18 As can be seen, when the receiving coil 4 rotates around its central axis at points E, F, G, and H, the output voltage remains stable without any significant drop, and the fluctuation amplitude is controlled within a small range. This indicates that the magnetic field distribution is relatively uniform in the effective energy transfer space inside the transmitting coil cavity, and the system has good omnidirectional energy transfer characteristics.

[0064] Analysis shows that the three-dimensional transmitting coil described in this invention satisfies the requirement of transmission direction insensitivity, and the magnetic field distribution inside the transmitting coil is uniform. It is suitable for omnidirectional wireless power transmission in space within a cuboid region. This invention can achieve true three-dimensional omnidirectional wireless power transmission.

[0065] The omnidirectional wireless power transmission device with a semi-open transmitting coil according to the present invention has the following beneficial effects: 1. The semi-open transmitting coils of the present invention are arranged into an orthogonal cuboid frame structure, which can form a magnetic field covering the inside of the coil. When the receiving coil is in different positions and angles inside the transmitting coil, the current excitation phase of the three transmitting coils supplied to the three-dimensional transmitting coil is adjusted by the three-phase full-bridge inverter circuit, so that the three transmitting coils can generate a omnidirectional spatial uniform rotating magnetic field, so that the receiving coil can receive energy at any position and angle within the effective range of the transmitting coil.

[0066] 2. The three-dimensional transmitting coil structure of the present invention overcomes the limitations of transmission direction sensitivity and low magnetic field utilization of existing three-dimensional coil structures, and improves the high degree of freedom and high flexibility of the receiving coil in spatial position.

[0067] 3. Compared with traditional three-dimensional transmitting coils, this invention can meet the requirements of transmission direction sensitivity, the magnetic field distribution is more uniform on all observation surfaces, and the magnetic field utilization rate is improved, making it more suitable for omnidirectional wireless power transmission in space.

[0068] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention.

[0069] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0070] Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The reference to "embodiment" herein means that a specific feature, structure, or characteristic described in connection with an embodiment can be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily indicate the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0071] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. An omnidirectional wireless power transmission device with a semi-open transmitting coil, comprising a transmitting end and a receiving end, characterized in that, The transmitter includes: Multiple sets of transmitting coil units are electrically isolated from each other and enclose a semi-open cuboid frame, with each set of transmitting coil units forming at least one face of the cuboid frame, and the cuboid frame having a cavity. Three-phase full-bridge inverter circuit; The primary-side resonant compensation circuit is connected between the three-phase full-bridge inverter circuit and the transmitting coil; The receiving end includes: The receiving coil (4) can be completely placed inside the cavity; The secondary side resonant compensation circuit is connected to the receiving coil (4); The rectifier and filter circuit is connected to the secondary resonant compensation circuit.

2. The omnidirectional wireless power transmission device with a semi-open transmitting coil according to claim 1, characterized in that, The transmitting coil unit includes: Two first transmitting coils (1) are aligned to form the two sides of the cuboid frame and connected in series to form a first transmitting coil unit; Two second transmitting coils (2) are arranged adjacent to and orthogonal to the first transmitting coil (1), and are connected in series to form a second transmitting coil unit; The third transmitting coil (3) has multiple square coils connected in series to form the third transmitting coil unit, which serves as the bottom surface of the cuboid frame.

3. The omnidirectional wireless power transmission device with a semi-open transmitting coil according to claim 2, characterized in that, The first transmitting coil (1) and the second transmitting coil (2) have the same structure, both being rectangular coils, with the length of the long side being twice the width of the short side.

4. The omnidirectional wireless power transmission device with a semi-open transmitting coil according to claim 2, characterized in that, The square coil includes: The first coil (31) is located on the bottom surface of the cuboid frame; Two second coils (32) are placed parallel to the first coil (31), connected in series and then connected to the first coil (31).

5. The omnidirectional wireless power transmission device with a semi-open transmitting coil according to claim 4, characterized in that, Two second coils (32) are placed symmetrically along the diagonal of the first coil (31).

6. The omnidirectional wireless power transmission device with a semi-open transmitting coil according to claim 5, characterized in that, The side length of each second coil (32) is half the side length of the first coil (31).

7. The omnidirectional wireless power transmission device with a semi-open transmitting coil according to claim 4, characterized in that, The excitation currents of the two first transmitting coils (1) that make up the first transmitting coil unit are in the same direction; The excitation currents of the two second transmitting coils (2) that make up the second transmitting coil unit are in the same direction; The currents in the two second coils (32) that make up the third transmitting coil unit are in opposite directions.

8. The omnidirectional wireless power transmission device with a semi-open transmitting coil according to claim 1, characterized in that, The three-phase full-bridge inverter circuit consists of three units, each corresponding to one of the three transmitting coil units.

9. The omnidirectional wireless power transmission device with a semi-open transmitting coil according to claim 8, characterized in that, The three-phase current of the three-phase full-bridge inverter circuit i A , i B , i C The amplitude and frequency are the same.

10. The omnidirectional wireless power transmission device with a semi-open transmitting coil according to claim 9, characterized in that, The phase relationship of the three-phase currents is as follows: the initial phase of the first phase current is 0. ° The initial phase of the second phase current is 180°. ° The initial phase of the third phase current is 90°. ° .

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