A control system and method for maximizing the charging power of a three - layer three - dimensional wireless charging library for drones

Abstract

The present invention discloses a control system and method for maximizing the charging power of a three - layer stereoscopic UAV wireless charging library. A control system for maximizing the charging power of a three - layer stereoscopic UAV wireless charging library is built, and the system includes a three - layer UAV wireless charging platform; resonance is configured according to the sizes and frequencies of the transmitting coil and the receiving coil to determine the size of the compensation capacitor; whether there is a load on the charging platform is monitored, and five charging scenarios are determined according to the number of loads on the three - layer charging platform; in each charging scenario, the charging power of each UAV is monitored, and according to the charging power and the size of the compensation capacitor, the topology, frequency and connection mode of the transmitting coil are determined to maximize the UAV charging power of the entire system. The present invention achieves the basic task of maximizing the power for the application scenario of the UAV charging library, improves the output power and application flexibility of the system, extends the service life of the charging equipment, and significantly improves the charging efficiency and stability.

Description

Technical Field

[0001] The present invention belongs to the technical field of wireless charging, and particularly relates to a control system and method for maximizing the charging power of a three - layer three - dimensional drone wireless charging library. Background Art

[0002] In recent years, drone inspection has become the most widely used inspection method for power grids. However, drones have the problem of high power consumption. The traditional wired charging method can only provide power once, resulting in the inability of drones to work for a long time, efficiently perform inspection tasks, and ensure the overall operation efficiency. Since wireless power transmission technology is non - contact power supply, only by assembling wireless power transmitting and receiving devices, the inspection drones can be wirelessly charged. The wireless charging technology has multiple advantages in inspection drones, so it has received wide attention. The structure of the magnetic - coupling wireless power transmission system mainly includes an alternating power source, a resonant topology circuit, a transmitting coil, a receiving coil, a rectifier, a filter, and a load. Wireless power transmission poses great challenges in terms of transmission distance. The coupling strength between the transmitting - end and receiving - end coils decreases rapidly with the increase of the transmission distance, resulting in a significant decrease in the wireless power transmission efficiency as the transmission distance increases. Under the existing research background, usually, the method of adding relay coils is considered to enhance the coupling and expand the transmission distance of the wireless power transmission system. However, in the application scenario of the drone charging library, there is no suitable installation position for the relay coils, which affects the charging power of the drones. Summary of the Invention

[0003] Object of the Invention: The object of the present invention is to provide a control system and method for maximizing the charging power of a three - layer three - dimensional drone wireless charging library to solve the problem of insufficient power caused by excessive transmission distance.

[0004] Technical solution: The present invention relates to a control system for maximizing the charging power of a three - layer three - dimensional unmanned aerial vehicle (UAV) wireless charging library, which includes: a power circuit and a control circuit. The power circuit includes a full - bridge inverter and a UAV wireless charging library. The UAV wireless charging library includes three charging platforms. Each charging platform includes a transmitting end on the charging platform, a receiving end on the UAV, a rectifying circuit, and a filtering circuit. The full - bridge inverter outputs three - way high - frequency alternating current to the transmitting ends of the three charging platforms respectively. The transmitting end and the receiving end are magnetically coupled. The signal output by the receiving end is successively passed through the rectifying circuit and the filtering circuit to charge the UAV. The control circuit includes an inverter dual - frequency output circuit and a monitoring circuit. The inverter dual - frequency output circuit is used to output high - frequency or low - frequency alternating current. The monitoring circuit includes three charging platform monitoring circuits, which are respectively used for power monitoring and quantity monitoring of the UAVs on the three charging platforms. According to the monitored power and the number of UAVs, the charging frequency, topology of each transmitting end, and the coil connection mode between each transmitting end are determined to maximize the charging power of the UAVs in the whole system.

[0005] Optionally, the frequency of the low - frequency alternating current output by the inverter dual - frequency output circuit is the basic charging frequency f1 of the transmitting end, and the high - frequency alternating current is the auxiliary charging frequency f2. When the transmitting end transfers energy to the receiving end on the same charging platform, the basic charging frequency f1 is used. When the transmitting end transfers energy to the receiving end of the adjacent charging platform, the auxiliary charging frequency f2 is used.

[0006] Optionally, the transmitting end includes a transmitting coil and its resonant network, and the receiving end includes a receiving coil and its resonant network.

[0007] The topology circuit of the receiving coil adopts the S topology.

[0008] When the power of the UAV is less than SOC1, both the transmitting coil and the receiving coil adopt the S topology, and the system uses the S - S topology for charging.

[0009] When the power of the UAV is greater than SOC1, the transmitting coil switches from the S topology to the LCC topology, and the system uses the LCC - S topology for charging.

[0010] Optionally, the coil connection mode between each transmitting end is as follows:

[0011] When three UAVs are charging in the charging library, the coils of the three transmitting ends are connected in parallel.

[0012] When the UAV on the third - layer charging platform finishes charging and flies away from the charging library, the UAVs on the first - layer and second - layer charging platforms continue to charge. The transmitting coil of the third - layer charging platform charges the UAV on the second - layer charging platform, and the first - layer transmitting coil and the second - layer transmitting coil are connected in parallel and then connected in series with the third - layer transmitting coil.

[0013] When the drone on the second - layer charging platform finishes charging and flies away from the charging depot, the drones on the first - layer and third - layer charging platforms continue to charge; the transmitting coil of the second - layer charging platform charges the drones on the first - layer and third - layer charging platforms. The first - layer transmitting coil and the third - layer transmitting coil are connected in parallel and then in series with the second - layer transmitting coil;

[0014] When the drones on the second - layer charging platform and the drones on the third - layer charging platform finish charging and fly away from the charging depot, the drones on the first - layer charging platform continue to charge; the second - layer transmitting coil charges the drones on the first - layer charging platform. The second - layer transmitting coil and the third - layer transmitting coil are connected in parallel and then in series with the first - layer transmitting coil;

[0015] When the drones on the first - layer charging platform and the drones on the third - layer charging platform finish charging and fly away from the charging depot, the drones on the second - layer charging platform continue to charge; both the first - layer and second - layer transmitting coils charge the drones on the second - layer charging platform. The first - layer transmitting coil and the third - layer transmitting coil are connected in parallel and then in series with the second - layer transmitting coil.

[0016] Optionally, both the transmitting coil and the receiving coil adopt a planar spiral coil structure,

[0017] The control method of the control system for maximizing the charging power of the three - layer stereoscopic drone wireless charging depot of the present invention includes the following steps:

[0018] Build a control system for maximizing the charging power of the three - layer stereoscopic drone wireless charging depot;

[0019] Configure resonance according to the size and frequency of the transmitting coil and the receiving coil to determine the size of the compensation capacitor;

[0020] Monitor whether there is a load on the charging platform. According to the number of loads on the three - layer charging platform, determine five charging scenarios; in each charging scenario, monitor the charging power of each drone. When the power of the drone is less than SOC1, both the transmitting coil and the receiving coil adopt the S - topology, and the system charges using the S - S topology; when the power of the drone is greater than SOC1, the transmitting coil switches from the S - topology to the LCC - topology, and the system charges using the LCC - S topology; when the drone finishes charging and leaves the charging platform, the operating frequency of the transmitting coil on this layer of the charging platform switches to high - frequency, and the topology switches to the S - topology, so that it charges the drones on the adjacent charging platform, ultimately maximizing the charging power of the drones in the whole system.

[0021] Furthermore, configure resonance according to the size and frequency of the transmitting coil and the receiving coil to determine the size of the compensation capacitor; specifically:

[0022] When the system topology is the S - S topology, the compensation capacitor of the transmitting coil is:

[0023] ,

[0024] The compensation capacitor of the receiving coil is:

[0025] ,

[0026] When the system topology is LCC-S, the compensation capacitor of the transmitting coil is:

[0027] ,

[0028] The compensation capacitor of the receiving coil is:

[0029] ,

[0030] Among them, is the self-inductance of the transmitting coil, is the self-inductance of the receiving coil, is the angular frequency, is the compensation inductance.

[0031] Furthermore, the five charging scenarios are specifically as follows:

[0032] The first charging scenario: All three drones are charging in the warehouse. In this case, the three drones charge normally; until the battery level of the drones reaches SOC1, the battery level monitoring circuit sends a signal, and the system topology switches from S-S topology to LCC-S topology, and then the three transmitting coils are connected in parallel;

[0033] The second charging scenario: The drone on the third charging platform finishes charging and flies out of the charging warehouse, and the drones on the first and second charging platforms continue to charge; the load monitoring circuit sends a signal to switch the frequency of the third transmitting coil from the basic charging frequency f1 to the auxiliary charging frequency f2, and the topology of the third transmitting coil switches from LCC topology to S topology to charge the drone on the second charging platform. The first transmitting coil and the second transmitting coil are connected in parallel and then connected in series with the third transmitting coil;

[0034] The third charging scenario: The drone on the second charging platform finishes charging and flies out of the charging warehouse, and the drones on the first and third charging platforms continue to charge; the load monitoring circuit sends a signal to switch the frequency of the second transmitting coil from the basic charging frequency f1 to the auxiliary charging frequency f2, and switches from LCC topology to S topology to charge the drones on the first and third charging platforms. The first transmitting coil and the third transmitting coil are connected in parallel and then connected in series with the second transmitting coil;

[0035] The fourth charging scenario: The drones on the second - layer charging platform and the drones on the third - layer charging platform finish charging and fly away from the charging depot, and the drones on the first - layer charging platform continue to charge; the load monitoring circuit sends a signal to switch the frequencies of the second - layer transmitting coil and the third - layer transmitting coil from the basic charging frequency f1 to the auxiliary charging frequency f2, and switch from the LCC topology to the S topology. The second - layer transmitting coil charges the drones on the first - layer charging platform, and the second - layer transmitting coil and the third - layer transmitting coil are connected in parallel and then in series with the first - layer transmitting coil.

[0036] The fifth charging scenario: The drones on the first - layer charging platform and the drones on the third - layer charging platform finish charging and fly away from the charging depot, and the drones on the second - layer charging platform continue to charge; the load monitoring circuit sends a signal to switch the frequencies of the first - layer transmitting coil and the third - layer transmitting coil from the basic charging frequency f1 to the auxiliary charging frequency f2, and switch from the LCC topology to the S topology. Both the first - layer and the second - layer transmitting coils charge the drones on the second - layer charging platform, and the first - layer transmitting coil and the third - layer transmitting coil are connected in parallel and then in series with the second - layer transmitting coil.

[0037] Furthermore, the transmission power between the transmitting coil and the receiving coil at the auxiliary charging frequency f2 is obtained by setting different high - frequency values according to the specific requirements of the user; specifically:

[0038] Let , where is the transmission power between the transmitting coil and the receiving coil when the frequency of the transmitting coil is the basic charging frequency f1, is the transmission power between the transmitting coil and the receiving coil when the frequency is the auxiliary charging frequency f2;

[0039] When the transmitting coils of adjacent charging platforms participate in transmitting power, before the drone's battery level reaches SOC1:

[0040] ,

[0041] where is the angular frequency at the basic charging frequency f1, is the angular frequency at the auxiliary charging frequency f2, is the mutual inductance value between the transmitting coil and the receiving coil, is the internal resistance of the compensation coil, is the internal resistance of the transmitting coil, is the internal resistance of the receiving coil, is the load resistance;

[0042] After the drone's battery level reaches SOC1:

[0043] ,

[0044] Among them, is the compensation inductor, is the compensation capacitor of the transmitting coil.

[0045] The present invention also provides an electronic device, including a memory and a processor, wherein:

[0046] The memory is used to store a computer program that can run on the processor;

[0047] The processor is used to execute the steps of the control method when running the computer program.

[0048] Beneficial effects: Compared with the prior art, the remarkable technical effects of the present invention are as follows: Through the design of a three - layer three - dimensional UAV wireless charging library, combined with the design of a power circuit and a control circuit, the maximization of charging power is achieved; A magnetic - coupled resonance wireless power transmission circuit is adopted, and the switching between the fundamental frequency f1 and the auxiliary frequency f2 is realized through an inverter dual - frequency output circuit to ensure efficient charging of the UAV in different charging scenarios; The monitoring circuit dynamically adjusts the charging topology (switching between S - S topology and LCC - S topology) and the operating frequency of the transmitting coil through power monitoring and load monitoring to ensure the stability and efficiency of the charging process; In addition, through the flexible switching of the parallel and series connection methods of the transmitting coil in different charging scenarios, the charging power of the system is further improved; The combination of these technical features not only solves the problem of insufficient power caused by excessive transmission distance, but also significantly improves the stability of the system and the service life of the charging device, meeting the needs of long - term UAV patrol. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 is a schematic diagram of the circuit principle of the control system of the present invention;

[0050] Figure 2 is a flowchart of the control method of the present invention;

[0051] Figure 3 is a block diagram of the power circuit structure of the UAV wireless charging library;

[0052] Figure 4 is a schematic diagram of five charging scenarios of the UAV wireless charging library, where (a) is a schematic diagram of the first charging scenario, (b) is a schematic diagram of the second charging scenario, (c) is a schematic diagram of the third charging scenario, (d) is a schematic diagram of the fourth charging scenario, and (e) is a schematic diagram of the fifth charging scenario;

[0053] Figure 5 is a schematic diagram of the transmitting coil topology circuit;

[0054] Figure 6 is a schematic diagram of the load monitoring control circuit. DETAILED DESCRIPTION OF THE INVENTION

[0055] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. The examples of the embodiments are shown in the drawings. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention, but should not be construed as limiting the present invention.

[0056] As Figure 1 shown, the maximum power control system for the three - layer stereo UAV wireless charging library of the present invention includes a DC power supply Vin, a power circuit, a control circuit, and a load. The DC power supply is used to provide electrical energy for the entire system, and the load is a UAV.

[0057] The power circuit includes a full - bridge inverter and a three - layer UAV wireless charging library. The three - layer UAV wireless charging library includes a first charging platform, a second charging platform, and a third charging platform. Each charging platform includes a magnetically coupled resonant wireless power transfer circuit, a rectifier circuit, and a filter circuit connected in sequence. The magnetically coupled resonant wireless power transfer circuit includes a transmitter end disposed on the charging platform and a receiver end disposed on the UAV. The transmitter end includes a transmitting coil and its resonant network, and the receiver end includes a receiving coil and its resonant network. The DC power supply is converted by the full - bridge inverter to output high - frequency alternating current and is respectively connected to the input ends of the three charging platforms. That is, the high - frequency alternating current output by the full - bridge inverter is input to the input end of the magnetically coupled resonant wireless power transfer circuit. The output of the magnetically coupled resonant wireless power transfer circuit is connected to the rectifier circuit and the filter circuit in sequence to convert the alternating current into direct current. However, the rectified direct current is not completely smooth but has a large pulsating component. The filter circuit can smooth these pulsations through the charge - discharge characteristics of the capacitor and output a more stable direct current to ensure that the UAV can obtain a stable power supply.

[0058] The control circuit includes an inverter dual-frequency output circuit and a monitoring circuit. The purpose of the inverter dual-frequency output circuit is to output high-frequency and low-frequency alternating current. The hardware design of a multi-level inverter is combined with the control strategy of multi-level modulation technology to enable an inverter to generate two outputs with different frequencies simultaneously, and the output waveform has high quality and low harmonic content. The monitoring circuit includes a first charging platform monitoring circuit, a second charging platform monitoring circuit, and a third charging platform monitoring circuit. The first charging platform monitoring circuit, the second charging platform monitoring circuit, and the third charging platform monitoring circuit are respectively used to monitor the first charging platform, the second charging platform, and the third charging platform. Each charging platform monitoring circuit includes a UAV power monitoring circuit and a UAV number monitoring circuit. The UAV power monitoring circuit is used to monitor the power of the UAV during charging on the charging platform. When the power of the UAV is less than SOC1, a switch on-off signal is issued. The transmitting coil and the receiving coil of this layer both adopt the S topology, and the entire system uses the S-S topology for charging. When the power of the UAV is greater than SOC1, a switch on-off signal is issued, and the transmitting coil of this layer switches from the S topology to the LCC topology, and the entire system topology switches to LCC-S for charging. The UAV number monitoring circuit is used to monitor whether there is a UAV on the charging platform. When the UAV flies away after charging, a signal is issued, and the operating frequency of the transmitting coil on this charging platform switches from f1 to f2, increasing the transmission distance of the transmitting coil of this layer, so that energy can be transmitted to the UAV on the adjacent charging platform, that is, charging the UAV on the adjacent charging platform. Since the transmission power of the S-S topology is greater than that of the LCC-S topology, the LCC topology of the layer transmitting coil is simultaneously switched to the S topology to increase the charging power. On the basis of determining the system topology and frequency, the series-parallel connection method between the transmitting coils is designed to maximize the system charging power. According to different charging scenarios, the control strategy also changes accordingly.

[0059] The full-bridge inverter is connected by four MOS tubes (S1, S2, S3, and S4) as Figure 1 shown, and its three output alternating currents are respectively input into the magnetic coupling resonant wireless power transmission circuits of the first charging platform, the second charging platform, and the third charging platform.

[0060] The receiving coil topology will adopt the S topology. In the early stage of UAV charging, it is S-S topology charging, which can provide an output characteristic of approximately constant current near the resonant frequency, conforming to the initial stage of battery charging (constant current charging stage), and can provide a stable current for the load, avoiding damage to the battery caused by current fluctuations. In the later stage of UAV charging, it is LCC-S topology charging, which can provide an output characteristic of approximately constant voltage near the resonant frequency, conforming to the later stage of battery charging (constant voltage charging stage), and avoiding overcharging to protect the battery.

[0061] When the transmitting coil transfers energy to the receiving coil on this platform, low-frequency transmission is adopted, and the frequency is set to f1 at this time. f1 is part of the recommended operating frequency range in the Qi standard formulated by the Wireless Power Consortium. Selecting f1 can ensure compatibility with existing wireless charging devices; when the transmitting coil transfers energy to the receiving coil of an adjacent charging platform, f2 is used for transmission, and the specific setting depends on the user's needs.

[0062] Specifically, the mutual inductance performance between the transmitting coil and the receiving coil is the key to determining the performance of the magnetic coupling resonance wireless power transmission circuit. The shape and material properties of the coupling coils directly affect the transmission power and transmission efficiency of the system.

[0063] In terms of the shape selection of the transmitting coil and the receiving coil, a planar spiral coil structure is adopted. During application, it is only necessary to ensure that the coupling coils are coaxial, and it has an ideal quality factor and coupling coefficient.

[0064] In terms of the material selection of the transmitting coil and the receiving coil, the main indicators are the self-inductance performance and high-frequency impedance of the wire. The high-frequency impedance of the planar spiral coil includes two parts: the DC resistance and the AC impedance. Among them, the DC resistance is determined by the material of the wire, the winding length, and the cross-sectional area, and is expressed as:

[0065] (1),

[0066] Among them, represents the DC resistance of the coil, is the resistivity of the wire, is the number of turns of the coil, is the winding length of the coil, is the wire diameter.

[0067] It can be seen from Equation (1) that to reduce the DC resistance of the coil, a wire with a larger wire diameter and a lower resistivity should be selected, and the winding length of the coil should be reduced as much as possible. On this basis, the high-frequency coil also needs to consider the AC impedance generated by the skin effect under high-frequency excitation.

[0068] The AC resistance of the planar spiral coil can be expressed as:

[0069] (2),

[0070] Among them, represents the AC resistance of the coil, is an irrational number, is the vacuum permeability, is the operating frequency, is the conductivity.

[0071] As can be seen from Equation (2), the wire diameter is the main influencing factor for the AC resistance of the planar spiral coil. The larger the wire diameter, the more obvious the skin effect, and the greater the AC resistance.

[0072] To reduce high-frequency losses and suppress the skin effect, Litz wire is used to wind the planar spiral coil. Litz wire is a high-frequency wire made by stranding multiple enameled wires. This process evenly distributes the eddy currents passing through the wire, thereby achieving a uniform distribution of the induced magnetic field.

[0073] As Figure 2 shown, the method for maximizing the charging power of a three-layer stereoscopic UAV wireless charging library according to the present invention includes the following steps:

[0074] S1. Build a control system for maximizing the charging power of a three-layer stereoscopic UAV wireless charging library as Figure 1 shown; specifically:

[0075] In this embodiment, the height of each charging platform is 50 cm, that is, the distance between adjacent charging platforms is 50 cm. A transmitting coil is laid on each charging platform. When the UAV flies into the charging library, energy can be transmitted through the coupling between the transmitting coil and the receiving coil. Both the transmitting coil and the receiving coil adopt planar spiral coils, where the radius of the transmitting coil is 130 mm and the radius of the receiving coil is 80 mm.

[0076] S2. Configure resonance according to the sizes and frequencies of the transmitting coil and the receiving coil to determine the size of the compensation capacitor; specifically:

[0077] When the system topology is S-S topology, the compensation capacitor of the transmitting coil is:

[0078] (3),

[0079] The compensation capacitor of the receiving coil is:

[0080] (4),

[0081] When the system topology is LCC-S, the compensation capacitor of the transmitting coil is:

[0082] (5),

[0083] The compensation capacitor of the receiving coil is:

[0084] (6),

[0085] Among them, is the self - inductance of the transmitting coil, is the self - inductance of the receiving coil, is the angular frequency, is the compensation inductance.

[0086] S3. Monitor whether there is a load (drone) on the charging platform. According to the number of loads on the three - layer charging platform, determine the charging scenario, the operating frequency of each transmitting coil, and the connection method between the transmitting coils; in each charging scenario, monitor the charging power of each drone, and according to the power of the drone, determine the transmitting coil topology to maximize the charging power of the drones in the whole system.

[0087] As Figure 3 shown, each drone wireless charging platform includes a magnetically coupled resonant wireless power transfer circuit, a rectifier circuit, and a filter circuit connected in sequence. The magnetically coupled resonant wireless power transfer circuit includes a transmitting end arranged on the charging platform and a receiving end arranged on the drone. The transmitting end includes a transmitting coil and its resonant network, and its resonant network includes LCC resonance and S resonance. The receiving end includes a receiving coil and its resonant network, and its resonant network is S resonance. The DC power supply is converted into high - frequency alternating current through a full - bridge inverter and is connected to the input ends of the three charging platforms respectively, that is, the high - frequency alternating current output by the full - bridge inverter is input to the input end of the magnetically coupled resonant wireless power transfer circuit. The output of the magnetically coupled resonant wireless power transfer circuit is connected to the rectifier circuit and the filter circuit in sequence. Among them, the rectifier circuit is composed of four diodes connected to convert alternating current into direct current. However, the rectified direct current is not completely smooth but has a large pulsating component. The filter circuit is composed of filter capacitors. Through the charging and discharging characteristics of the capacitors, these pulsations can be smoothed to output a more stable direct current.

[0088] Specifically, from Figure 4 in (a) to (e), it can be seen that there are five charging scenarios for the three - layer charging library of the present invention. The specific monitoring in each charging scenario is as follows:

[0089] The first charging scenario:

[0090] All three drones are charging in the library. In this case, the three drones charge normally until the power of the drones reaches SOC1. Then the power monitoring circuit sends a signal, and the system topology switches from S - S topology to LCC - S topology. Then the three transmitting coils are connected in parallel to maximize the charging power of the drones in the whole system.

[0091] The second charging scenario:

[0092] The drone on the third layer finishes charging and flies away from the charging station. The drones on the first and second layers continue to charge. At this time, since the charging platform on the third layer is vacant, the load monitoring circuit sends a signal to switch the frequency of the transmitting coil on the third layer from the basic charging frequency f1 to the auxiliary charging frequency f2, and the topology of the transmitting coil on the third layer is switched from the LCC topology to the S topology to charge the drones on the second layer. Since the frequencies of the transmitting coil on the second layer and the transmitting coil on the third layer are different at this time, no interference will occur.

[0093] Among them, the reflected impedance of the transmitting coil on the third layer is:

[0094] (7),

[0095] Among them, is the angular frequency corresponding to the auxiliary charging frequency f2, is the mutual inductance between the transmitting coil on the third layer and the receiving coil on the second layer, is the external circuit impedance of the receiving coil on the second layer.

[0096] The reflected impedance of the transmitting coil on the first layer or the transmitting coil on the second layer is:

[0097] (8),

[0098] Among them, is the reflected impedance of the transmitting coil on the first layer or the transmitting coil on the second layer, is the angular frequency corresponding to the basic charging frequency f1, is the mutual inductance between the transmitting coil on the first layer or the transmitting coil on the second layer and the receiving coil of its respective layer, is the external circuit impedance of the receiving coil on the first layer or the receiving coil on the second layer.

[0099] It can be known through simulation that , so .

[0100] Since the three transmitting coils are in parallel at this time, and , it will cause the input voltage of the transmitting coil on the third layer to decrease, and then pull down the input voltages of the other two transmitting coils, thereby reducing the charging power of the system. Therefore, it is necessary to change the connection relationship between the transmitting coils at this time, that is, the transmitting coil on the first layer and the transmitting coil on the second layer are still in parallel, and then in series with the transmitting coil on the third layer to increase the charging power.

[0101] The third charging scenario:

[0102] The drone on the second layer finishes charging and flies away from the charging depot, while the drones on the first and third layers continue charging. At this time, since the charging platform on the second layer is vacant, the load monitoring circuit sends a signal to switch the frequency of the transmitting coil on the second layer from the basic charging frequency f1 to the auxiliary charging frequency f2, and also switches from the LCC topology to the S topology to charge the drones on the first and third layers. Because the reflected impedance difference is large, the connection mode of the transmitting coils is switched to parallel connection of the transmitting coil on the first layer and the transmitting coil on the third layer, and then series connection with the transmitting coil on the second layer to increase the charging power.

[0103] The fourth charging scenario:

[0104] The drones on the second layer and the third layer finish charging and fly away from the charging depot, while the drone on the first layer continues charging. At this time, since the charging platforms on the second and third layers are vacant, the load monitoring circuit sends a signal to switch the frequencies of the transmitting coils on the second layer and the third layer from the basic charging frequency f1 to the auxiliary charging frequency f2, and also switches from the LCC topology to the S topology. The transmitting coil on the second layer charges the drone on the first layer. At this time, the transmitting coil on the third layer may not be able to transmit energy due to the excessive distance. Because the reflected impedances of the transmitting coils on the second layer and the third layer are very small, the connection mode of the coils is switched to parallel connection of the transmitting coil on the second layer and the transmitting coil on the third layer, and then series connection with the transmitting coil on the first layer to increase the charging power.

[0105] The fifth charging scenario:

[0106] The drones on the first layer and the third layer finish charging and fly away from the charging depot, while the drone on the second layer continues charging. At this time, since the charging platforms on the first and third layers are vacant, the load monitoring circuit sends a signal to switch the frequencies of the transmitting coils on the first layer and the third layer from the basic charging frequency f1 to the auxiliary charging frequency f2, and also switches from the LCC topology to the S topology. Both the transmitting coil on the first layer and the transmitting coil on the third layer charge the drone on the second layer. Because the reflected impedances of the transmitting coils on the first layer and the third layer are very small, the connection mode of the coils is switched to parallel connection of the transmitting coil on the first layer and the transmitting coil on the third layer, and then series connection with the transmitting coil on the second layer to increase the charging power.

[0107] Furthermore:

[0108] To make the battery life of the drone longer and meet the charging curve of the lithium battery, a control circuit is set at the transmitting end to switch the topology, specifically as Figure 5 shown. The topology circuit of the transmitting coil includes the first switch a, the second switch b, the first capacitor C 1, the second capacitor C 2, the third capacitor C 3, the compensation inductor and the self-inductance of the transmitting coil , the first switch a controls the S topology, and the second switch b controls the LCC topology. When the first switch a is closed and the second switch b is open, the first capacitor C 1 and the transmitting coil form a closed path with the power supply. When the first switch a is open and the second switch b is closed, the second capacitor C 2 and the self-inductance of the transmitting coil are connected in series and then paralleled with the third capacitor C 3, and then connected in series with the compensation inductor and then form a closed path with the power supply U S ; The switch a controls the S topology, and the switch b controls the LCC topology. When the battery level of the drone reaches SOC1, the battery level monitoring circuit of the drone sends a signal to open the switch a and close the switch b, and the S-S topology is switched to the LCC-S topology; When the drone finishes charging and a new low-battery drone flies into the drone storage for charging, the battery level monitoring circuit of the drone sends a signal to open the switch b and close the switch a, and the LCC-S topology is switched to the S-S topology. The S topology is that the compensation capacitor is connected in series with the coil, while the LCC topology consists of an inductor and two capacitors. When the drone enters the storage for charging, the entire system is switched from the S-S constant current topology to the LCC-S constant voltage topology, which conforms to the charging curve of the drone lithium battery and can extend the life of the drone battery.

[0109] Furthermore:

[0110] As Figure 6 shown, by monitoring whether there is a drone docked on the charging platform to send a signal. When there is a drone docked on the charging platform, the corresponding transmitting coil frequency is transmitted at the basic charging frequency, that is, f1; When it is monitored that there is no drone docked on the charging platform, the monitoring circuit sends a signal, and the transmitting coil frequency is switched from the basic charging frequency f1 to the auxiliary charging frequency f2 to transmit energy to the drone docked on the adjacent charging platform, as Figure 5 shown, and at the same time the charging topology is switched from LCC-S to S-S to increase the charging power.

[0111] Specifically, the charging power of each drone is:

[0112] where is the transmission power between the transmitting coil and the receiving coil when the transmitting coil frequency is the basic charging frequency f1, is the transmission power between the transmitting coil and the receiving coil when the frequency is the auxiliary charging frequency f2. It can be obtained by setting different high-frequency values according to different specific requirements of users.

[0113] The expression of the transmission power of the coil at the auxiliary charging frequency f2 is:

[0114] (9),

[0115] Among them, is the angular frequency in the case of the auxiliary charging frequency f2, is the mutual inductance value between the transmitting coil and the receiving coil, is the AC power supply, is the load resistance value, is the equivalent internal resistance of the AC power supply, is the internal resistance of the transmitting coil, is the internal resistance of the receiving coil.

[0116] Furthermore, when the frequency is the basic charging frequency f1 and before the UAV battery level reaches SOC1, the charging topology is the S-S topology. At this time, the expression for the transmission power between the transmitting coil and the receiving coil is:

[0117] (10),

[0118] Among them, is the angular frequency in the case of the basic charging frequency f1, is the internal resistance of the compensation coil.

[0119] When the UAV battery level reaches SOC1, the charging topology switches to the LCC-S topology. At this time, the expression for the transmission power between the transmitting coil and the receiving coil is:

[0120] (11),

[0121] Among them, is the compensation inductance value, is the compensation capacitor of the transmitting coil.

[0122] It can be seen from the above analysis that by simply changing the operating frequency of the transmitting coil, the charging power required by the user can be obtained.

[0123] Specifically, let ,

[0124] Therefore, when the transmitting coils of adjacent platforms participate in transmitting power, before the UAV battery level reaches SOC1,

[0125] (12),

[0126] After the UAV battery level reaches SOC1,

[0127] (13),

[0128] The present invention achieves the basic task of maximizing power for the UAV charging library application scenario, improves the output power and application flexibility of the system by using topology switching and a simple control circuit, effectively improves the stability of the system, and extends the service life of the charging equipment.

[0129] The present invention also provides an electronic device, including a memory and a processor, wherein:

[0130] The memory is used for storing a computer program that can run on the processor;

[0131] The processor is used for executing the steps of the control method when running the computer program.

[0132] Although the specific embodiments of the present invention have been described above, those skilled in the art of the present invention understand that the specific embodiments we described are illustrative rather than used to limit the scope of the present invention. Equivalent modifications and variations made by those skilled in the art in accordance with the spirit of the present invention should be covered within the scope protected by the present invention.

Claims

1. A three-dimensional three-layer UAV wireless charging warehouse charging power maximization control system, characterized in that: include: Power circuit and control circuit. The power circuit includes a full-bridge inverter and a wireless charging depot for unmanned aerial vehicles. The wireless charging depot for unmanned aerial vehicles includes a three-layer charging platform. Each charging platform includes a transmitter located on the charging platform, a receiver located on the unmanned aerial vehicle, a rectifier circuit and a filter circuit. The full-bridge inverter outputs three high-frequency alternating currents to the transmitters of the three-layer charging platforms respectively. The transmitter and the receiver are connected by magnetic coupling. The output signal of the receiver passes through the rectifier circuit and the filter circuit in turn to charge the unmanned aerial vehicle. The control circuit includes an inverter dual-frequency output circuit and a monitoring circuit. The inverter dual-frequency output circuit is used to output high-frequency or low-frequency alternating current. The monitoring circuit includes three charging platform monitoring circuits. The three charging platform monitoring circuits are used to monitor the power and quantity of unmanned aerial vehicles on the three-layer charging platform respectively. The charging frequency, topology and coil connection method of each transmitter are determined according to the monitored power and the number of unmanned aerial vehicles to maximize the unmanned aerial vehicle charging power of the entire system. The transmitting end includes a transmitting coil and a resonant network thereof, and the receiving end includes a receiving coil and a resonant network thereof; The receiving coil topology circuit adopts S topology; When the drone's power is less than SOC1, both the transmitting coil and the receiving coil use the S topology, and the system uses the SS topology for charging; When the drone's power level is greater than SOC1, the transmitting coil switches from the S topology to the LCC topology, and the system uses the LCC-S topology for charging; The coil connection between each transmitting end is as follows: When all three drones are charging in the charging station, the coils of the three transmitters are connected in parallel; When the drones on the third-layer charging platform are fully charged and fly away from the charging station, the drones on the first-layer charging platform and the second-layer charging platform continue to charge; the transmitting coil of the third-layer charging platform charges the drones on the second-layer charging platform, and the first-layer transmitting coil is connected in parallel with the second-layer transmitting coil and then connected in series with the third-layer transmitting coil; When the drones on the second-level charging platform are fully charged and fly away from the charging station, the drones on the first-level and third-level charging platforms continue to charge; the transmitting coil of the second-level charging platform charges the drones on the first-level and third-level charging platforms, and the first-level transmitting coil is connected in parallel with the third-level transmitting coil and then connected in series with the second-level transmitting coil; When the drones on the second and third charging platforms are fully charged and fly away from the charging station, the drones on the first charging platform continue to charge; the second transmitting coil charges the drones on the first charging platform, and the second transmitting coil is connected in parallel with the third transmitting coil and then in series with the first transmitting coil; When the drones on the first and third charging platforms are fully charged and fly away from the charging station, the drones on the second charging platform continue to charge; the first and second transmitting coils both charge the drones on the second charging platform, and the first transmitting coil is connected in parallel with the third transmitting coil and then in series with the second transmitting coil.

2. The three-dimensional three-layer UAV wireless charging station charging power maximization control system according to claim 1 is characterized in that: The frequency of the low-frequency AC power output by the inverter dual-frequency output circuit is the basic charging frequency f1 of the transmitter, and the frequency of the high-frequency AC power is the auxiliary charging frequency f2. The basic charging frequency f1 is used when the transmitter transmits energy to the receiving end on the current charging platform, and the auxiliary charging frequency f2 is used when the transmitter transmits energy to the receiving end of the adjacent charging platform.

3. The three-dimensional three-layer UAV wireless charging station charging power maximization control system according to claim 1 is characterized in that: Both the transmitting coil and the receiving coil adopt a planar spiral coil structure.

4. A control method using the three-dimensional three-layer UAV wireless charging depot charging power maximization control system according to any one of claims 1 to 3, characterized in that: The following steps are involved: Build a three-dimensional three-layer drone wireless charging depot to maximize charging power control system; Configure resonance according to the size and frequency of the transmitting coil and the receiving coil, and determine the size of the compensation capacitor; Monitor whether there is load on the charging platform, and determine five charging scenarios based on the number of loads on the three-layer charging platform; in each charging scenario, monitor the charging power of each drone. When the power of the drone is less than SOC1, the transmitting coil and the receiving coil both adopt the S topology, and the system adopts the SS topology for charging; when the power of the drone is greater than SOC1, the transmitting coil switches from the S topology to the LCC topology, and the system adopts the LCC-S topology for charging; when the drone completes charging and leaves the charging platform, the operating frequency of the transmitting coil on this layer of the charging platform switches to high frequency, and the topology switches to the S topology, so that it can charge the drones on the adjacent charging platform and ultimately maximize the drone charging power of the entire system.

5. The control method according to claim 4, characterized in that: According to the size and frequency of the transmitting coil and the receiving coil, the resonance is configured and the size of the compensation capacitor is determined; specifically: When the system topology is SS topology, the compensation capacitor of the transmitting coil for: ， Compensation capacitor for receiving coil for: ， When the system topology is LCC-S, the compensation capacitor of the transmitting coil for: ， Compensation capacitor for receiving coil for: ， in, is the self-inductance of the transmitting coil, is the self-inductance of the receiving coil, is the angular frequency, To compensate for the inductance.

6. The control method according to claim 4, characterized in that: The five charging scenarios are as follows: The first charging scenario: All three drones are charged in the warehouse. In this case, the three drones are charged normally. When the power of the drone reaches SOC1, the power monitoring circuit sends a signal, and the system topology switches from SS topology to LCC-S topology, and then the three transmitting coils are connected in parallel. The second charging scenario: the drone on the third-layer charging platform is fully charged and flies away from the charging depot, while the drones on the first-layer charging platform and the second-layer charging platform continue to charge; the load monitoring circuit sends a signal to switch the frequency of the third-layer transmitting coil from the basic charging frequency f1 to the auxiliary charging frequency f2, and the topology of the third-layer transmitting coil is switched from the LCC topology to the S topology to charge the drone on the second-layer charging platform. The first-layer transmitting coil is connected in parallel with the second-layer transmitting coil and then in series with the third-layer transmitting coil; The third charging scenario: the drones on the second-layer charging platform are fully charged and fly away from the charging depot, while the drones on the first-layer and third-layer charging platforms continue to charge; the load monitoring circuit sends a signal to switch the frequency of the second-layer transmitting coil from the basic charging frequency f1 to the auxiliary charging frequency f2, and switches from the LCC topology to the S topology to charge the drones on the first-layer and third-layer charging platforms. The first-layer transmitting coil is connected in parallel with the third-layer transmitting coil and then connected in series with the second-layer transmitting coil; The fourth charging scenario: the drones on the second-layer charging platform and the third-layer charging platform are fully charged and fly away from the charging depot, while the drones on the first-layer charging platform continue to charge; the load monitoring circuit sends a signal to switch the frequency of the second-layer transmitting coil and the third-layer transmitting coil from the basic charging frequency f1 to the auxiliary charging frequency f2, and switch from the LCC topology to the S topology. The second-layer transmitting coil charges the drones on the first-layer charging platform, and the second-layer transmitting coil and the third-layer transmitting coil are connected in parallel and then in series with the first-layer transmitting coil; The fifth charging scenario: the drones on the first-layer charging platform and the third-layer charging platform complete charging and fly away from the charging depot, while the drones on the second-layer charging platform continue to charge; the load monitoring circuit sends a signal to switch the frequency of the first-layer transmitting coil and the third-layer transmitting coil from the basic charging frequency f1 to the auxiliary charging frequency f2, and switch from the LCC topology to the S topology. The first-layer and second-layer transmitting coils both charge the drones on the second-layer charging platform. The first-layer transmitting coil and the third-layer transmitting coil are connected in parallel and then in series with the second-layer transmitting coil.

7. The control method according to claim 6, characterized in that: The transmission power between the transmitting coil and the receiving coil when the frequency is the auxiliary charging frequency f2 is obtained by setting different high frequency values ​​according to the specific requirements of the user; specifically: make ,in, is the transmission power between the transmitting coil and the receiving coil when the transmitting coil frequency is the basic charging frequency f1, is the transmission power between the transmitting coil and the receiving coil when the frequency is the auxiliary charging frequency f2; When the transmitting coil of the adjacent charging platform participates in the power transmission, before the drone reaches SOC1: ， in, is the angular frequency at the basic charging frequency f1, is the angular frequency of the auxiliary charging frequency f2, is the mutual inductance between the transmitting coil and the receiving coil, To compensate for the internal resistance of the coil, is the internal resistance of the transmitting coil, is the internal resistance of the receiving coil, is the load resistance; When the drone battery reaches SOC1: ， in, To compensate for the inductance, is the compensation capacitance of the transmitting coil.

8. An electronic device, characterized in that comprising a memory and a processor, wherein: A memory for storing computer programs that can be run on the processor; A processor, configured to execute the steps of the control method as claimed in any one of claims 4 to 7 when running the computer program.

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