A power transmitter and a wireless charging device

Abstract

The present application belongs to the field of wireless charging technology, and in particular, relates to an electric energy transmitter and a wireless charging device. Although there are some improvements in the coil and the position of the mobile transmitter, it is necessary to design complex software and hardware and communication systems to realize the control of the transmitter. The application provides an electric energy transmitter, including a microprocessing unit, a power amplification unit and a Helmholtz coil unit connected in sequence, the microprocessing unit is connected to a detection circuit unit; the detection circuit unit includes a first detection circuit and a second detection circuit, the Helmholtz coil unit includes a first transmitting resonant coil and a second transmitting resonant coil, the first transmitting resonant coil is connected to the first detection circuit, the first detection circuit is connected to the microprocessing unit, the second transmitting resonant coil is connected to the second detection circuit, and the second detection circuit is connected to the microprocessing unit. The structure is simple and easy to operate.

Description

Technical Field

[0001] The present application belongs to the field of wireless charging technology, and in particular, relates to a power transmitter and a wireless charging device. Background Art

[0002] At present, wireless charging technologies include electromagnetic induction, electric field coupling, radio wave, and magnetic resonance. The first type of electromagnetic induction wireless charging system can be regarded as a separate transformer. The alternating voltage is input into the transmitting coil to generate an alternating magnetic field, which induces current in the receiving coil to achieve energy transmission. Electromagnetic induction technology is the most mature and common wireless charging technology at present. Its transmission efficiency can reach up to about 80%, but the transmission distance is short, usually less than 1cm. In addition, the equipment has low flexibility and the receiving coil must be placed directly above the transmitting coil. The second type of electric field coupling wireless charging system uses the induced electric field generated by two sets of asymmetric dipoles coupled in the vertical direction to transfer the electric energy from the transmitting end to the receiving end. Its advantage is that the transmission efficiency can reach up to about 70%, but the transmission distance is short, usually only working in the millimeter range. The third type of radio wave wireless charging system uses electromagnetic waves as energy transmission signals to achieve energy transmission through transmitting antennas and receiving antennas. Its advantage is that the energy transmission distance is long, up to several meters. However, the energy transmission efficiency is low, only about 30% at most, and there is radiation damage to the human body. The fourth type of magnetic coupling resonance wireless charging system uses the principle that energy can be efficiently transmitted during resonance. The resonant circuit frequencies of the transmitter and the receiver are the same to achieve a resonant state, and energy is transferred from the transmitter to the receiver. Its advantages are that the energy transmission efficiency can reach up to about 60%, the energy transmission distance can reach tens of centimeters, and it is flexible to use. The receiver can be placed at any angle, and wireless charging can be achieved even if there are obstacles in the middle.

[0003] The application of magnetic coupling resonance wireless charging technology on drones must take into account the poor landing accuracy of drones. In order to ensure efficient energy transmission, the wireless charging system must have a high tolerance for the misalignment of the transmitting coil and the receiving coil. Although there have been some improvements in the coil and the position of the mobile transmitter, they all require the design of complex software, hardware and communication systems to achieve the control of the transmitter. Summary of the invention

[0004] 1. Technical issues to be solved

[0005] The application of magnetic coupling resonance wireless charging technology on drones must take into account the poor landing accuracy of drones. In order to ensure efficient energy transmission, the wireless charging system must have a high tolerance for the misalignment of the transmitting coil and the receiving coil. Although there are some improvements in the coil and the position of the mobile transmitter, it is necessary to design complex software, hardware and communication systems to achieve the control of the transmitter. This application provides a power transmitter and a wireless charging device.

[0006] 2. Technical solution

[0007] In order to achieve the above-mentioned purpose, the present application provides an electric energy transmitting end, comprising a microprocessing unit, a power amplifying unit and a Helmholtz coil unit connected in sequence, wherein the microprocessing unit is connected to a detection circuit unit;

[0008] The detection circuit unit includes a first detection circuit and a second detection circuit, and the Helmholtz coil unit includes a first transmitting resonant coil and a second transmitting resonant coil, the first transmitting resonant coil is connected to the first detection circuit, the first detection circuit is connected to the microprocessing unit, the second transmitting resonant coil is connected to the second detection circuit, and the second detection circuit is connected to the microprocessing unit.

[0009] Optionally, the first transmitting resonant coil is an LC resonant coil, and the second transmitting resonant coil is an LC resonant coil.

[0010] Optionally, the LC resonant coil is wound with Litz wire.

[0011] The present application provides a wireless charging device, comprising the power transmitting end as described above;

[0012] It also includes an electric energy receiving end, the electric energy receiving end includes a receiving resonant coil, a rectifying and filtering unit, a voltage stabilizing unit and a second microprocessing unit connected in sequence, the voltage stabilizing unit is connected to a third detection circuit, the second microprocessing unit is connected to the third detection circuit, and the voltage stabilizing unit is connected to a battery to be charged;

[0013] The receiving resonant coil is disposed between the first transmitting resonant coil and the second transmitting resonant coil.

[0014] Optionally, the first transmitting resonant coil and the second transmitting resonant coil are placed horizontally, the first transmitting resonant coil is arranged on a first charging plate, and the second transmitting resonant coil is arranged on a second charging plate.

[0015] Optionally, a radius of the first transmitting resonant coil is equal to a radius of the second transmitting resonant coil, and the radius is equal to a distance between the first transmitting resonant coil and the second transmitting resonant coil.

[0016] Optionally, the receiving resonant coil is an LC resonant coil.

[0017] Optionally, it also includes a wireless communication terminal, which includes a Bluetooth unit, and the Bluetooth unit is used to obtain information about the operating status of the power receiving terminal and adjust the energy signal transmitted by the power transmitting terminal.

[0018] Optionally, the uniformity δ of the magnetic field between the first transmitting resonant coil and the second transmitting resonant coil is expressed by the following formula:

[0019]

[0020] Among them, B max is the maximum value of the magnetic field, B min is the minimum value of the magnetic field, B avg is the average value of the magnetic field.

[0021] Optionally, the power receiving end is arranged on a drone.

[0022] 3. Beneficial effects

[0023] Compared with the prior art, the power transmitter and wireless charging device provided by the present application have the following beneficial effects:

[0024] The power transmitting end provided by the present application can generate a uniform magnetic field in the charging area by setting a first transmitting resonant coil and a second transmitting resonant coil. The flexibility of the position of the receiving resonant coil of the power receiving end is improved. When charging the power transmitting end of the wireless charging device, efficient and stable charging can be completed without moving the transmitting resonant coil or adjusting the array. This wireless charging device ensures that the charging efficiency of the load does not change significantly with different landing positions, and no manual intervention is required during the charging process, thereby realizing a completely autonomous charging operation. The wireless charging device involved in the present application has a simple structure and is easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the structure of the electric energy transmitting end of the present application;

[0026] Figure 2 It is a schematic diagram of the principle of the wireless charging device of the present application;

[0027] Figure 3 It is a schematic diagram of the structure of the wireless charging device of the present application;

[0028] Figure 4 It is a schematic diagram of the coil position in the wireless charging device of the present application;

[0029] Figure 5It is a schematic diagram of the magnetic field distribution of a single transmitting resonant coil of the present application;

[0030] Figure 6 It is a schematic diagram of the magnetic field distribution of two transmitting resonant coils of the present application;

[0031] Figure 7 It is a schematic diagram of the structure of the wireless charging device for drones of the present application;

[0032] In the figure: 1- microprocessor unit, 2- power amplifying unit, 3- first detection circuit, 4- second detection circuit, 5- first transmitting resonant coil, 6- second transmitting resonant coil, 7- receiving resonant coil, 8- rectification and filtering unit, 9- voltage stabilizing unit, 10- second microprocessor unit, 11- third detection circuit, 12- battery to be charged, 13- first charging plate, 14- second charging plate. DETAILED DESCRIPTION

[0033] Hereinafter, the specific embodiments of the present application will be described in detail with reference to the accompanying drawings. According to these detailed descriptions, those skilled in the art can clearly understand the present application and can implement the present application. Without violating the principles of the present application, the features in the various embodiments can be combined to obtain new implementations, or certain features in certain embodiments can be replaced to obtain other preferred implementations.

[0034] After the establishment of AirFuel, the international wireless charging standard alliance, the unification of standards has accelerated the widespread popularization of magnetic coupling resonance wireless charging technology. Due to the requirements of charging efficiency and charging distance, drones mainly use this technology for wireless charging. The application of magnetic coupling resonance wireless charging technology in drones has become a research hotspot in the current wireless charging field.

[0035] The multi-transmitter coil charging board based on the principle of magnetic coupling resonance charges the drone. The main circuit in the ground charging base station consists of a coil array to mitigate the negative impact of the coupling coefficient caused by possible misalignment between the receiving and transmitting coils due to imperfect landing. An automatic battery charging station is set up, and the drone can automatically land, charge the battery, and then continue the flight mission.

[0036] A high-power and high-efficiency wireless power transmission system based on the principle of coupled magnetic resonance to automatically charge the batteries of small drones. The drone is equipped with a receiving circular coil with an electronic system for controlling the battery charging process, while the transmitting circular coil is placed on a ground base station and connected to the power feeding system. In order to improve the tolerance for misalignment that may always exist between the transmitting and receiving coils, the primary coil is placed on an electric positioning system to achieve perfect alignment. This patent solves the problem of a significant reduction in charging efficiency caused by the low precision of the drone landing system, but the device structure is complex, difficult to implement, and the stability achieved is not high.

[0037] Resonant circuit refers to the situation in an AC RLC circuit when the voltage or current is at its maximum value. That is, the reactance of the inductor and capacitor cancel each other out, and the power provided by the power source falls on the resistor. Resonant circuits are often used in radio and wireless communications.

[0038] LC resonance, in a circuit containing capacitors and inductors, if the capacitors and inductors are connected in parallel, may occur in a very small period of time: the voltage of the capacitor gradually increases, while the current gradually decreases; at the same time, the current of the inductor gradually increases, while the voltage of the inductor gradually decreases.

[0039] Helmholtz coils refer to a pair of identical current-carrying circular coils that are parallel to each other and coaxial, and carry current in the same direction. When the coil spacing is equal to the coil radius, the total magnetic field of the two current-carrying coils is uniform over a large range near the midpoint of the axis.

[0040] See also Figures 1 to 7 , the present application provides an electric energy transmitting end, comprising a microprocessing unit 1, a power amplifying unit 2 and a Helmholtz coil unit connected in sequence, wherein the microprocessing unit 1 is connected to a detection circuit unit;

[0041] The detection circuit unit includes a first detection circuit 3 and a second detection circuit 4, and the Helmholtz coil unit includes a first transmitting resonant coil 5 and a second transmitting resonant coil 6, the first transmitting resonant coil 5 is connected to the first detection circuit 3, the first detection circuit 3 is connected to the microprocessing unit 1, the second transmitting resonant coil 6 is connected to the second detection circuit 4, and the second detection circuit 4 is connected to the microprocessing unit 1.

[0042] The first transmitting resonant coil 5 and the second transmitting resonant coil 6 have the same structure. The first and the second are just for distinction. The first transmitting resonant coil 5 and the second transmitting resonant coil 6 are referred to as transmitting coils. As one of the most important components for transmitting energy, the characteristics of the transmitting coil directly affect the performance of the entire wireless charging device. The structure of the transmitting coil is optimized so that the magnetic field generated by the transmitting coil is as evenly distributed as possible, so that the energy transmission efficiency of the system does not change with the relative position of the power transmitting end and the power receiving end.

[0043] Optionally, the first transmitting resonant coil 5 is an LC resonant coil, and the second transmitting resonant coil 6 is an LC resonant coil.

[0044] Optionally, the LC resonant coil is wound with Litz wire.

[0045] The present application also provides a wireless charging device, characterized in that it includes the power transmitting end as described above;

[0046] It also includes an electric energy receiving end, which includes a receiving resonant coil 7, a rectifying and filtering unit 8, a voltage stabilizing unit 9 and a second microprocessing unit 10 connected in sequence, the voltage stabilizing unit 9 is connected to a third detection circuit 11, the second microprocessing unit 10 is connected to the third detection circuit 11, and the voltage stabilizing unit 9 is connected to a battery to be charged 12;

[0047] The receiving resonant coil 7 is disposed between the first transmitting resonant coil 5 and the second transmitting resonant coil 6 .

[0048] The first detection circuit 3, the second detection circuit 4 and the third detection circuit 11 in the present application have the same structure, and the numbers are only for clear distinction. Similarly, the structures of the micro-processing unit 1 and the second micro-processing unit 10 are also the same.

[0049] Optionally, the first transmitting resonant coil 5 and the second transmitting resonant coil 6 are placed horizontally, the first transmitting resonant coil 5 is arranged on the first charging plate 13 , and the second transmitting resonant coil 6 is arranged on the second charging plate 14 .

[0050] Optionally, a radius of the first transmitting resonant coil 5 is equal to a radius of the second transmitting resonant coil 6 , and the radius is equal to a distance between the first transmitting resonant coil 5 and the second transmitting resonant coil 6 .

[0051] Optionally, the receiving resonant coil 7 is an LC resonant coil.

[0052] Optionally, it also includes a wireless communication terminal, which includes a Bluetooth unit, and the Bluetooth unit is used to obtain information about the operating status of the power receiving terminal and adjust the energy signal transmitted by the power transmitting terminal.

[0053] Optionally, the uniformity δ of the magnetic field between the first transmitting resonant coil 5 and the second transmitting resonant coil 6 is expressed by the following formula:

[0054]

[0055] Among them, B max is the maximum value of the magnetic field, B min is the minimum value of the magnetic field, B avg is the average value of the magnetic field.

[0056] The magnetic field distribution of single transmitting coil and double transmitting coil is as follows Figure 5 and Figure 6 The magnetic field uniformity of the wireless charging system using the dual transmitting coil structure is greatly improved, so that the receiving resonant coil 7 in the uniform magnetic field can be charged efficiently and stably without being aligned with the center of the transmitting resonant coil.

[0057] Optionally, the power receiving end is arranged on a drone.

[0058] Figure 4 It is a dual transmitting coil and a single receiving coil in a wireless charging device. The power transmitting end includes two identical circular coils, which are placed horizontally to form a Helmholtz coil unit. Each circular transmitting coil is wound with Litz wire, the radius of the transmitting coil is r, and the spacing between the two transmitting coils is 2d. The circular receiving resonant coil 7 placed at any position between the two transmitting coils is also wound with Litz wire, and the radius of the receiving resonant coil 7 is roughly equal to the width of the specific drone. Equal alternating currents I in the same direction are passed through the two transmitting coils. When the relationship between the transmitting coil spacing and the transmitting coil radius satisfies d=r, the alternating magnetic fields generated by the two transmitting coils are superimposed to form a relatively uniform magnetic field.

[0059] Power transmitter: The frequency of the primary resonator composed of the transmitting coil and capacitor in the magnetic coupling resonance transmission mode is 6.78MHz. After the power supply is connected, the power amplifier outputs a 6.78MHz sinusoidal signal, which is passed into the two transmitting coils respectively. Because the LC resonant coil at the transmitting end and the LC resonant coil at the receiving end have the same resonant frequency, they will reach a resonant state in the alternating magnetic field. The power transmitter adds a corresponding detection circuit to detect the current of the transmitting coil and then transmit it to the microprocessor unit 1 to determine whether the power transmitter is working normally.

[0060] Power receiving end: The LC resonant coil installed on the power receiving end of the drone will convert the induced magnetic field into an AC signal, which will be output as a stable DC voltage after the rectification and filtering unit 8 and voltage conversion to charge the battery of the drone. The third detection circuit 11 detects the voltage value output by the voltage stabilizing unit 9 and transmits the signal to the second microprocessing unit 10, so as to timely understand the current energy transmission power and send error information to the power transmitting end in time.

[0061] Wireless communication terminal: Establish a wireless communication terminal based on Bluetooth technology to continuously obtain information about the operating status of the power receiving terminal on the drone, so as to timely adjust the energy signal transmitted by the power transmitting terminal. The Bluetooth communication process is divided into four stages: 1) Perception stage: The power transmitting terminal Bluetooth senses whether there is a drone approaching that needs power; 2) Identification and configuration stage: When a drone approaches, the power transmitting terminal identifies the identity of the receiving terminal based on the received data packet and establishes the power transmission conditions of the transmitting terminal that meet the power supply requirements of the receiving drone; 3) Power transmission stage: The power transmitting terminal transmits power according to the requirements, and feeds back the output voltage of the power receiving terminal, energy transmission power and other parameters to the power transmitting terminal in real time, so as to realize real-time control of the wireless charging device.

[0062] Take drone wireless charging as an example

[0063] Figure 7 The figure is a schematic diagram of a wireless charging device for drones. The device contains two horizontally placed transmitting coils, and the radius of the transmitting coil is set to 3 times the width of the drone to ensure that the drone can land on the charging board with a high probability with the landing accuracy of existing drones. The two transmitting coils are embedded in two charging boards respectively, and the spacing is equal to the radius of the transmitting coil itself. After the drone lands at any position on the charging board, the feeding signal of the power transmitter is turned on, and two currents I in the same direction are passed into the transmitting coil. The charging status of the power receiving end, such as charging efficiency, charging completion, charging abnormality and other information, is fed back to the power transmitting end via Bluetooth to ensure the normal permission of the charging device and the timely closure of the power transmitting end after charging is completed.

[0064] According to the specific power supply requirements of the UAV, the power transmitter and the power receiver are set to ensure efficient and stable energy transmission.

[0065] In recent years, drones have been widely used in military and commercial fields, but their short battery life has become a bottleneck problem restricting the further development of drones. As one of the mainstream technologies in the field of wireless energy transmission, magnetic coupling resonance wireless charging technology has the advantages of high energy transmission efficiency and long transmission distance, and is an effective way to solve the power supply problem of drones. This application aims to solve the problems of high energy transmission stability and low flexibility of the receiving end position in the existing drone wireless charging system. Based on the principle of magnetic coupling resonance wireless energy transmission, a new type of wireless charging device is designed to improve the charging performance of the system and meet the purpose of actual application scenarios.

[0066] The power transmitting end composed of dual transmitting coils is also called the charging plate. In order to solve the problem that the landing position of the drone cannot be accurately controlled, resulting in large differences in charging efficiency and low charging stability, the wireless charging device based on magnetic coupling resonance proposed in this application can generate a uniform magnetic field in the charging area. After the drone to be charged lands on the charging plate and starts charging, the power receiving end installed on the drone is always in a relatively uniform magnetic field. No matter where the drone lands on the charging plate, the charging efficiency will not change significantly due to the different relative positions between the transmitting coil and the receiving resonant coil 7, thereby achieving efficient and stable energy transmission.

[0067] The power transmitting end provided by the present application can generate a uniform magnetic field in the charging area by setting a first transmitting resonant coil and a second transmitting resonant coil. The flexibility of the position of the receiving resonant coil of the power receiving end is improved. When charging the power transmitting end of the wireless charging device, efficient and stable charging can be completed without moving the transmitting resonant coil or adjusting the array. This wireless charging device ensures that the charging efficiency of the load does not change significantly with different landing positions, and no manual intervention is required during the charging process, thereby realizing a completely autonomous charging operation. The wireless charging device involved in the present application has a simple structure and is easy to operate.

[0068] This application can not only be used for wireless charging of single-load drones, but can also be expanded to wireless charging of multi-load drones, and can also be expanded to wireless charging applications of electric vehicles, industrial mobile robots, etc.

[0069] Although the present application is described above with reference to specific embodiments, it should be understood by those skilled in the art that many modifications may be made to the configurations and details disclosed in the present application within the principles and scope disclosed in the present application. The scope of protection of the present application is determined by the appended claims, and the claims are intended to cover all modifications included in the equivalent literal meaning or scope of the technical features in the claims.

Claims

1. An electric energy transmitter, characterized in that: It comprises a microprocessing unit (1), a power amplification unit (2) and a Helmholtz coil unit which are connected in sequence, wherein the microprocessing unit (1) is connected to a detection circuit unit; The detection circuit unit comprises a first detection circuit (3) and a second detection circuit (4); the Helmholtz coil unit comprises a first transmitting resonant coil (5) and a second transmitting resonant coil (6); the first transmitting resonant coil (5) is connected to the first detection circuit (3); the first detection circuit (3) is connected to the microprocessing unit (1); the second transmitting resonant coil (6) is connected to the second detection circuit (4); and the second detection circuit (4) is connected to the microprocessing unit (1); The first transmitting resonant coil (5) and the second transmitting resonant coil (6) are both arranged in a horizontal direction, and the first transmitting resonant coil (5) is located above the second transmitting resonant coil (6); the radii of the first transmitting resonant coil (5) and the second transmitting resonant coil (6) are both r; The distance between the first transmitting resonant coil (5) and the second transmitting resonant coil (6) is 2d, wherein d=r; The currents flowing through the first transmitting resonant coil (5) and the second transmitting resonant coil (6) are alternating currents with the same direction and equal currents.

2. The electric energy transmitter as claimed in claim 1, characterized in that: The first transmitting resonant coil (5) is an LC resonant coil, and the second transmitting resonant coil (6) is an LC resonant coil.

3. The electric energy transmitter as claimed in claim 2, characterized in that: The LC resonant coil is wound with Litz wire.

4. A wireless charging device, characterized in that: It comprises the electric energy transmitting end as described in any one of claims 1 to 3; It also includes an electric energy receiving end, the electric energy receiving end including a receiving resonant coil (7), a rectifying and filtering unit (8), a voltage stabilizing unit (9) and a second microprocessing unit (10) connected in sequence, the voltage stabilizing unit (9) being connected to a third detection circuit (11), the second microprocessing unit (10) being connected to the third detection circuit (11), and the voltage stabilizing unit (9) being connected to a battery to be charged (12); The receiving resonant coil (7) is arranged between the first transmitting resonant coil (5) and the second transmitting resonant coil (6).

5. The wireless charging device according to claim 4, wherein: The first transmitting resonant coil (5) and the second transmitting resonant coil (6) are placed horizontally; the first transmitting resonant coil (5) is arranged on a first charging plate (13), and the second transmitting resonant coil (6) is arranged on a second charging plate (14).

6. The wireless charging device according to claim 5, wherein: The radius of the first transmitting resonant coil (5) is equal to the radius of the second transmitting resonant coil (6), and the radius is equal to the distance between the first transmitting resonant coil (5) and the second transmitting resonant coil (6).

7. The wireless charging device according to claim 6, wherein: The receiving resonant coil (7) is an LC resonant coil.

8. The wireless charging device according to claim 7, wherein: It also includes a wireless communication terminal, which includes a Bluetooth unit. The Bluetooth unit is used to obtain information about the operating status of the power receiving terminal and adjust the energy signal transmitted by the power transmitting terminal.

9. The wireless charging device according to claim 4, wherein: The uniformity δ of the magnetic field between the first transmitting resonant coil (5) and the second transmitting resonant coil (6) is expressed by the following formula: Among them, B max is the maximum value of the magnetic field, B min is the minimum value of the magnetic field, B avg is the average value of the magnetic field.

10. The wireless charging device according to claim 8, wherein: The power receiving end is arranged on the drone.

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