Unmanned aerial vehicle wireless energy taking control method, device and system

Abstract

The invention provides an unmanned aerial vehicle wireless energy taking control method, device and system, and relates to the technical field of power systems and wireless charging. The method comprises the steps of obtaining power transmission line current parameters; based on the power transmission line current parameters, target load modes are determined, and the target load modes comprise a pure resistive load mode and a resistive-capacitive load mode; according to the target load mode, adjusting impedance characteristics of an adjustable electronic load in the unmanned aerial vehicle wireless energy taking control device and excitation parameters of an energy taking iron core in the unmanned aerial vehicle wireless energy taking control device; and according to the adjusted excitation parameters and impedance characteristics, the unmanned aerial vehicle wireless energy taking control device is controlled to output stable direct current voltage. The method is used for improving the energy taking stability and the energy taking efficiency of the unmanned aerial vehicle in operation states such as inspection, so that the unmanned aerial vehicle can work continuously, and the overall operation efficiency is improved.

Description

Technical Field

[0001] This application relates to the fields of power systems and wireless charging technology, and in particular to a method, device and system for wireless power harvesting control of unmanned aerial vehicles. Background Technology

[0002] With the continuous advancement of technology, intelligent and power technologies are being applied more and more widely in numerous fields. Especially in power systems, drones, with their flexibility, efficiency, and remote control capabilities, have played an indispensable role in operations such as distribution network inspection, transmission line monitoring, and substation equipment inspection. This has not only significantly reduced labor costs and safety risks but also dramatically improved the accuracy and efficiency of inspections and operations. However, behind the superior performance of drones, their limited endurance remains a core bottleneck restricting their large-scale application in long-distance, continuous operation scenarios.

[0003] Currently, solutions to the drone range anxiety problem mainly include the following two approaches: First, lithium battery-based energy systems. However, this approach is limited by the energy density of current battery technology, making it difficult to meet the demands of long-duration operations with a single charge. Furthermore, the charging process typically requires manual intervention or reliance on fixed charging facilities, which to some extent restricts the drone's operational range and autonomy. Second, deploying fixed wireless charging base stations. By pre-positioning wireless charging base stations or helipads along inspection routes, drones can recharge when their power is low. While this solution alleviates range anxiety to some extent, it suffers from high infrastructure deployment costs, limited coverage, and the need for drones to frequently interrupt missions and precisely land at specific locations to recharge, meaning the operational process is not truly continuous.

[0004] It is evident that the existing methods still suffer from poor energy extraction efficiency when drones are used for long-term inspection of equipment lines, making it difficult to meet the requirements for efficient and continuous operation. Summary of the Invention

[0005] The UAV wireless power harvesting control method, device and system provided in this application are used to solve the problem that the existing methods still have poor power harvesting efficiency when UAVs are conducting long-term inspections of equipment lines, making it difficult to meet the requirements of high-efficiency and continuous operation.

[0006] In a first aspect, embodiments of this application provide a wireless power harvesting control method for unmanned aerial vehicles (UAVs), applied to a wireless power harvesting control device for UAVs, the method comprising:

[0007] Obtain transmission line current parameters;

[0008] Based on the transmission line current parameters, the target load mode is determined, including purely resistive load mode and resistive-capacitive load mode.

[0009] According to the target load mode, adjust the impedance characteristics of the adjustable electronic load in the UAV wireless power harvesting control device and the excitation parameters of the power harvesting iron core in the UAV wireless power harvesting control device.

[0010] Based on the adjusted excitation parameters and impedance characteristics, the wireless power harvesting control device of the UAV is controlled to output a stable DC voltage.

[0011] In one possible implementation, determining the target load mode based on the transmission line current parameter includes: comparing the transmission line current parameter with a preset current threshold; if the transmission line current parameter is less than the preset current threshold, then determining the target load mode as a purely resistive load mode; if the transmission line current parameter is greater than or equal to the preset current threshold, then determining the target load mode as a resistive-capacitive load mode.

[0012] In one possible implementation, when the target load mode is a purely resistive load mode, the impedance characteristics of the adjustable electronic load in the UAV wireless power harvesting control device and the excitation parameters of the power harvesting core in the UAV wireless power harvesting control device are adjusted according to the target load mode, including: determining the target resistance value corresponding to the maximum power harvesting based on the equivalent circuit model of the power harvesting core; controlling the adjustable electronic load to operate in a purely resistive mode and adjusting the resistance value of the adjustable electronic load to the target resistance value so that the excitation parameters of the power harvesting core operate in the maximum power power harvesting state.

[0013] In one possible implementation, the target resistance value corresponding to the maximum harvested power is determined based on the equivalent circuit model of the harvested core, including: obtaining the actual excitation parameters of the harvested core by conducting an no-load test on the harvested core; constructing an equivalent circuit model of the harvested core based on the actual excitation parameters; establishing a functional relationship between the harvested power and the load resistance based on the equivalent circuit model; performing a derivative operation on the functional relationship to obtain the load resistance value that maximizes the harvested power, and using the load resistance value as the target resistance value.

[0014] In one possible implementation, when the target load mode is a resistive-capacitive load mode, the impedance characteristics of the adjustable electronic load in the UAV wireless power harvesting control device and the excitation parameters of the power harvesting core in the UAV wireless power harvesting control device are adjusted according to the target load mode, including: determining the target capacitive reactance value based on the constant power power harvesting requirement; controlling the adjustable electronic load to work in resistive-capacitive mode, and adjusting the capacitive reactance value of the adjustable electronic load to the target capacitive reactance value so that the excitation parameters of the power harvesting core work in a constant power power harvesting state.

[0015] In one possible implementation, the UAV wireless power harvesting control device further includes a wireless power transmission module; after controlling the UAV wireless power harvesting control device to output a stable DC voltage according to the adjusted excitation parameters and impedance characteristics, the method further includes: driving the wireless power transmission module to work based on the stable DC voltage; determining the transmission efficiency parameters of the wireless power transmission module based on the coupling state between the transmitting coil and the receiving coil in the wireless power transmission module; and dynamically adjusting the circuit parameters of the wireless power transmission module according to the transmission efficiency parameters so that the wireless power transmission module is in a parity-time symmetrical operating state.

[0016] In one possible implementation, the circuit parameters of the wireless power transmission module are dynamically adjusted according to the transmission performance parameters to make the wireless power transmission module operate in a parity-time symmetrical state. This includes: determining whether the wireless power transmission module is operating in a parity-time symmetrical state based on the transmission performance parameters; if the wireless power transmission module is not operating in a parity-time symmetrical state, then dynamically adjusting the switching frequency of the Class E power amplifier in the wireless power transmission module, and / or the resonant parameters of the transmitting coil and the receiving coil, to make the wireless power transmission module operate in a parity-time symmetrical state.

[0017] In one possible implementation, the transmission performance parameter is the coupling coefficient between the transmitting coil and the receiving coil. Based on the transmission performance parameter, determining whether the wireless power transmission module is in a parity-time symmetric operating state includes: comparing the coupling coefficient with a critical coupling coefficient, which is constructed based on the equivalent series resistance, load resistance, inherent operating angular frequency of the resonator, and inductance of the receiving resonator in the wireless power transmission module; if the coupling coefficient is greater than or equal to the critical coupling coefficient, the wireless power transmission module is in a parity-time symmetric operating state; if the coupling coefficient is less than the critical coupling coefficient, the wireless power transmission module is not in a parity-time symmetric operating state.

[0018] In one possible implementation, the transmitting and receiving coils in the wireless power transmission module employ a low-loss capacitor segmented compensation structure, which is constructed by dispersing and connecting multiple compensation capacitors in series in the coil conductors; the method further includes: controlling the wireless power transmission module to operate at a target resonant frequency based on the capacitor segmented compensation structure.

[0019] In one possible implementation, before controlling the wireless power transfer module to operate at the target resonant frequency based on the capacitor segmentation compensation structure, the method further includes:

[0020] Obtain the distributed parameter simulation model of the transmitting coil and / or receiving coil in the wireless power transmission module. The distributed parameter simulation model is constructed based on electromagnetic field simulation tools.

[0021] Based on the distributed parameter simulation model, the number and location of compensation capacitors in the segmented capacitor compensation structure are optimized and analyzed to determine the segmented capacitor compensation scheme that meets the preset loss conditions at the target resonant frequency.

[0022] Secondly, embodiments of this application provide a wireless power harvesting control device for unmanned aerial vehicles, including a power harvesting core, an adjustable electronic load, a signal detection circuit, a BUCK circuit, and a DSP control circuit.

[0023] The energy-harvesting iron core is sleeved on the transmission line for coupling and harvesting AC power;

[0024] The input terminal of the adjustable electronic load is connected to the secondary winding of the energy-harvesting iron core, and the output terminal of the adjustable electronic load is connected to the input terminal of the BUCK circuit. The adjustable electronic load is used to adjust the equivalent impedance based on the control signal, and the BUCK circuit is used to output a stable DC voltage.

[0025] The input terminal of the signal detection circuit is connected to the secondary winding and / or the BUCK circuit; the signal detection circuit is used to obtain the transmission line current parameters.

[0026] The output terminal of the signal detection circuit is connected to the input terminal of the DSP control circuit, and the output terminal of the DSP control circuit is connected to the control terminal of the adjustable electronic load; wherein, the DSP control circuit is used to execute the first aspect and / or some of the possible implementations in the first aspect.

[0027] In one possible implementation, the UAV wireless power harvesting control device further includes a wireless power transmission module;

[0028] The input of the wireless power transfer module is connected to the output of the BUCK circuit to receive a stable DC voltage and wirelessly charge the drone.

[0029] The wireless power transfer module includes a Class E power amplifier, a transmitter-side resonant network, and a receiver-side resonant network, wherein the transmitter-side resonant network includes a transmitter coil, and the receiver-side resonant network includes a receiver coil.

[0030] The DSP control circuit is also used to execute some of the possible implementation methods described in the first aspect above.

[0031] In one possible implementation, the transmitting coil and / or receiving coil employ a segmented capacitor compensation structure; wherein, the segmented capacitor compensation structure is constructed by distributing multiple compensation capacitors in series within the coil conductors, in order to reduce the dielectric loss of the coil.

[0032] In one possible implementation, the DSP control circuit is also used to perform some of the possible implementations described in the first aspect above.

[0033] Thirdly, embodiments of this application provide a wireless power harvesting control system for unmanned aerial vehicles (UAVs), including the second aspect above and / or various possible wireless power harvesting control devices for UAVs as described in the second aspect above, as well as the UAV itself.

[0034] The drone is equipped with a receiving coil, which is used to receive wireless energy by resonant coupling with the transmitting coil in the drone's wireless power harvesting control device.

[0035] Fourthly, embodiments of this application provide an electronic device, including: a memory and a processor;

[0036] The memory stores instructions that the computer executes;

[0037] The processor executes computer execution instructions stored in memory, causing the processor to perform the first aspect and / or various possible implementations of the first aspect as described above.

[0038] Fifthly, embodiments of this application provide a computer-readable storage medium storing computer-executable instructions, which, when executed, are used to implement the first aspect and / or various possible implementations of the first aspect.

[0039] Sixthly, embodiments of this application provide a computer program product, including a computer program that, when executed, implements the first aspect and / or various possible implementations of the first aspect.

[0040] The UAV wireless power harvesting control method, device, and system provided in this application acquire transmission line current parameters, enabling real-time sensing of transmission line current changes. Based on the current magnitude, the load impedance characteristics are dynamically switched. Simultaneously, by adjusting excitation parameters, the influence of current fluctuations on magnetic flux is compensated, ensuring the device always operates in optimal condition. This overcomes the problem of unstable power harvesting when transmission line current fluctuates, ensuring a stable DC output voltage, improving UAV power harvesting efficiency, and thus ensuring the reliability of the UAV in long-term inspection missions. Furthermore, regardless of complex power line environments or dynamically changing inspection routes, efficient power harvesting can be achieved through appropriate load mode selection and parameter adjustment, greatly expanding the application range of UAVs. In addition, a stable power supply eliminates the need for frequent mission interruptions and recharging, allowing continuous inspection work, improving overall work efficiency, and facilitating the timely detection and handling of potential problems in the power system, ensuring the safe and stable operation of the power system. Attached Figure Description

[0041] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0042] Figure 1 Flowchart of the UAV wireless power harvesting and control method provided in this application Figure 1 ;

[0043] Figure 2 A schematic diagram of the equivalent circuit model provided in this application;

[0044] Figure 3 A schematic diagram of the connection of the capacitor segment compensation structure provided in this application;

[0045] Figure 4 A schematic diagram showing the specific connection of the capacitor segment compensation structure provided in this application;

[0046] Figure 5 Schematic diagram of the structure of the UAV wireless power harvesting control device provided in this application Figure 1 ;

[0047] Figure 6 A schematic diagram of the wireless power transmission module provided in this application;

[0048] Figure 7 A schematic diagram of the structure of the UAV wireless power harvesting control system provided in this application;

[0049] Figure 8 Flowchart of the UAV wireless power harvesting and control method provided in this application Figure 2 ;

[0050] Figure 9 Schematic diagram of the structure of the UAV wireless power harvesting control device provided in this application Figure 2 ;

[0051] Figure 10 The voltage and current waveforms output by the BUCK circuit provided in this application;

[0052] Figure 11 The simulated voltage waveform at the switching transistor of the Class E power amplifier provided in this application;

[0053] Figure 12 The actual measured voltage waveform at the switching transistor terminal of the Class E power amplifier provided in this application;

[0054] Figure 13 The simulation diagram showing the relationship between the UAV power replenishment efficiency and the coupling coefficient provided in this application;

[0055] Figure 14 A graph showing the actual measured relationship between the UAV refueling efficiency and the coupling coefficient provided for this application;

[0056] Figure 15 A schematic diagram of the structure of the electronic device provided in this application.

[0057] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0058] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0059] In existing technologies, traditional multi-rotor drones, due to battery capacity limitations, typically have a single flight duration of 10-20 minutes. This necessitates frequent return-to-base recharging during inspection operations, failing to meet the demands for long-distance, extended-duration inspections. For example, in power transmission line inspections, drones need to fly along lines hundreds of kilometers; frequent takeoffs and landings for recharging significantly reduce operational efficiency and may even lead to mission interruptions due to insufficient power. Furthermore, the high site dependence of base stations makes them difficult to deploy in complex terrain or dynamically changing inspection routes. The need for drones to hover or land during power harvesting increases operational time costs and impacts inspection efficiency. The high-precision alignment requirements of wireless charging are easily affected by factors such as wind speed and vibration in real-world environments, leading to decreased energy transmission efficiency. For instance, power line inspection environments are complex, with transmission lines often located in remote areas or at high altitudes. Traditional relay charging stations require fixed sites, are costly to build, and have poor adaptability, making them unsuitable for dynamic inspection needs.

[0060] To address the issue of poor energy harvesting efficiency, this application proposes a method that allows drones to directly obtain energy from power transmission lines that are ubiquitous in the power grid, enabling them to replenish energy in the air anytime and anywhere. However, the current on the power transmission lines fluctuates significantly with load changes, causing traditional fixed-parameter energy harvesting devices to have insufficient output power when the current is low, and to be damaged due to core saturation or overvoltage when the current is too high. This results in unstable energy harvesting power, making it difficult to meet the requirements of efficient and continuous operation.

[0061] Furthermore, based on the above-mentioned problems, this application provides a method, device, and system for wireless power harvesting control of unmanned aerial vehicles (UAVs). By acquiring the current parameters of the transmission line, the current state of the transmission line can be understood in real time, providing basic data for subsequent power harvesting control. By dynamically switching the load mode based on the current magnitude, the UAV can achieve relatively efficient power harvesting under different current conditions. After determining the load mode, adjusting the impedance characteristics of the adjustable electronic load and the excitation parameters of the power harvesting core is a key operation to achieve stable power harvesting. By adjusting these key parameters, the working state of the power harvesting control device is optimized so that it can better match the transmission line current, thereby improving the power harvesting efficiency. Finally, based on the adjusted parameters, the power harvesting device is controlled to output a stable DC voltage, providing continuous and reliable power support for the UAV and ensuring that it can perform tasks stably for a long time.

[0062] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will be described below with reference to the accompanying drawings.

[0063] This application provides a wireless power harvesting control method for unmanned aerial vehicles (UAVs), applied to a wireless power harvesting control device for UAVs. This device may include a power harvesting section, a control section, and a wireless power transmission section. The power harvesting section mainly consists of a power harvesting core and related circuitry, responsible for harvesting electrical energy from power transmission lines. The control section includes current sensors and control units, used to perform functions such as acquiring current parameters, determining load modes, and adjusting parameters. The wireless power transmission section includes a wireless power transmission module, a Class E power amplifier, and resonant networks on the transmitting and receiving sides, wirelessly transmitting the electrical energy harvested and converted by the power harvesting section to the UAV for charging.

[0064] In some examples, the performance and parameters of the energy harvesting core have a significant impact on the energy harvesting efficiency of the device. For instance, the selection of core materials, permeability, saturation magnetic flux density, and other parameters need to be optimized based on the current characteristics of the transmission line and the power requirements of the UAV. For example, the energy harvesting core can be designed based on the principle of a current transformer, such as an energy harvesting CT. Simultaneously, designs such as capacitor segmentation compensation structures can be combined to further improve device performance and reduce energy loss. The control unit, as the main control component of the device, can be implemented using high-performance chips such as DSPs (Digital Signal Processors). For example, a DSP control circuit can quickly and accurately process data from the current sensor, determine the target load mode according to a preset algorithm, and precisely adjust the parameters of the adjustable electronic load and the energy harvesting core.

[0065] This embodiment does not impose any particular restrictions on the type of wireless power harvesting control device for the UAV, as long as the transmission line current parameters can be obtained; based on the transmission line current parameters, the target load mode is determined, including a purely resistive load mode and a resistive-capacitive load mode; according to the target load mode, the impedance characteristics of the adjustable electronic load in the UAV wireless power harvesting control device and the excitation parameters of the power harvesting core in the UAV wireless power harvesting control device are adjusted; based on the adjusted excitation parameters and impedance characteristics, the UAV wireless power harvesting control device is controlled to output a stable DC voltage.

[0066] Figure 1 Flowchart of the UAV wireless power harvesting and control method provided in this application Figure 1 The execution entity of this method can be a server storing the UAV wireless power harvesting control method or other servers. This server can be a control module integrated into the UAV wireless power harvesting control device; however, this embodiment does not impose any particular limitations. Figure 1 As shown, the method may include:

[0067] S101. Obtain the transmission line current parameters.

[0068] Among these, transmission line current parameters refer to the relevant characteristic values ​​of the current in the transmission line, including information such as current magnitude, current frequency, and current waveform. Furthermore, current parameter data can be obtained by appropriately connecting current sensors and other detection devices in the drone's wireless power harvesting control device to the transmission line.

[0069] For example, electromagnetic induction current sensors convert changes in current in transmission lines into measurable electrical signals through the principle of electromagnetic induction, thereby obtaining current parameters. Some common clamp-on ammeters are based on this principle and can be easily clipped onto transmission lines for measurement.

[0070] Alternatively, fiber optic current sensors can be used, leveraging certain characteristics of optical fibers to sense current changes, offering advantages such as resistance to electromagnetic interference. This allows for applications requiring high measurement accuracy and interference immunity, such as high-voltage transmission line monitoring.

[0071] S102. Based on the transmission line current parameters, determine the target load mode, which includes a purely resistive load mode and a resistive-capacitive load mode.

[0072] Among them, a purely resistive load mode refers to a working mode in which the load is mainly composed of resistive elements, and the current and voltage are in phase. A resistive-capacitive load mode is a working mode in which the load is composed of a combination of resistive and capacitive elements, and the current phase leads the voltage phase.

[0073] In this step, the acquired current parameters can be analyzed and processed to determine which load mode to use based on preset judgment rules.

[0074] In one example, a current threshold is set to determine the load mode: when the current exceeds a certain set value, a purely resistive load mode is selected; when the current is less than that value, a resistive-capacitive load mode is selected. For example, if the current threshold is set to 10A, a purely resistive load mode is used when a current of 12A is detected.

[0075] In another example, the current waveform characteristics can be used to determine the load mode. For instance, if the current waveform is relatively regular and stable, a purely resistive load mode should be selected; if the waveform has some fluctuations or distortions, a resistive-capacitive load mode should be selected.

[0076] S103. Adjust the impedance characteristics of the adjustable electronic load in the UAV wireless power harvesting control device and the excitation parameters of the power harvesting core in the UAV wireless power harvesting control device according to the target load mode.

[0077] Among them, the impedance characteristics of the adjustable electronic load refer to the characteristics of its resistance, inductance and capacitance, which hinder the flow of current; the excitation parameters of the energy-harvesting iron core refer to the relevant parameters of the magnetic flux generated by the iron core under the action of the magnetic field, such as excitation current and permeability.

[0078] Furthermore, based on the determined target load mode, the impedance value of the adjustable electronic load and the excitation parameters of the energy-harvesting iron core can be changed through a preset control circuit or adjustment mechanism in the device. For example, components such as digital potentiometers and variable capacitors can be used, with their resistance or capacitance values ​​changed by a microcontroller outputting control signals. For instance, using a digital potentiometer, the resistance value can be adjusted by changing the tap position. Excitation parameters can be adjusted by changing the number of turns of the coil wound on the iron core or the voltage applied to the coil. For example, a relay can be used to switch coils with different numbers of turns to change the excitation effect.

[0079] S104. Based on the adjusted excitation parameters and impedance characteristics, control the output of the UAV wireless power harvesting control device to maintain a stable DC voltage.

[0080] In this step, a stable DC voltage can refer to a voltage whose magnitude and direction do not change over time, and which can continuously provide stable power to the drone.

[0081] In some examples, by utilizing adjusted parameters, the acquired electrical energy can be converted and stabilized through a pre-set power conversion circuit in the device, outputting a DC voltage that meets the requirements. Furthermore, voltage regulator chips, such as the LM7805 three-terminal voltage regulator, can be used to convert the unstable input voltage into a stable DC voltage output. Alternatively, switching power supply regulation can be employed, using rapid on / off control of the switching transistor, in conjunction with energy storage components and feedback control circuits, to achieve efficient voltage regulation.

[0082] The UAV wireless power harvesting control method provided in this application acquires its current parameters in real time, using these parameters as the basis for subsequent operations. Based on these parameters, the load mode is rationally determined, and the load impedance and core excitation parameters are effectively adjusted to optimize the internal state of the device, making it compatible with the external current characteristics. Ultimately, a stable DC voltage output is achieved, improving the stability, adaptability, and efficiency of the UAV's wireless power harvesting, and providing a reliable guarantee for the long-term stable operation of the UAV in fields such as power line inspection. Furthermore, this dynamic matching mechanism avoids the problem of power output fluctuations during sudden current changes in the traditional fixed load mode, enabling the device to output energy stably even under complex operating conditions (such as sudden current increases or decreases), significantly improving the continuity and reliability of the UAV's endurance. In addition, through the coordinated adjustment of excitation parameters and load characteristics, it can adapt to different transmission line current scenarios (such as low current or high current), further expanding the application scope of wireless power harvesting technology.

[0083] Based on the above embodiments, the method for determining the target load mode based on the transmission line current parameter described in S102 may include: comparing the transmission line current parameter with a preset current threshold; if the transmission line current parameter is less than the preset current threshold, then determining the target load mode as a purely resistive load mode; if the transmission line current parameter is greater than or equal to the preset current threshold, then determining the target load mode as a resistive-capacitive load mode.

[0084] In this embodiment, the preset current threshold can be a pre-set current value standard, serving as a critical value for determining which target load mode to select. This value can be determined comprehensively based on various factors such as the UAV's energy harvesting requirements, the characteristics of the energy harvesting device, and the common current range of the transmission line. For example, a suitable value can be set considering the minimum stable current required by the UAV during normal inspection and the current range in which the device can operate efficiently under different load modes.

[0085] In some embodiments, a fixed threshold comparison method can be used: a fixed current threshold is preset in the server corresponding to the UAV wireless power harvesting control. For example, it is set to 5A. When the obtained transmission line current parameter is 4A, since 4A is less than 5A, the target load mode is determined to be a purely resistive load mode; if the obtained current parameter is 6A, since 6A is greater than 5A, the target load mode is determined to be a resistive-capacitive load mode.

[0086] Alternatively, a dynamic threshold adjustment comparison method can be used: the preset current threshold is dynamically adjusted based on factors such as different time periods and the operating status of the transmission line. For example, during peak electricity consumption periods, the current in the transmission line is generally higher, so the preset current threshold can be appropriately increased; while during off-peak electricity consumption periods, the preset current threshold is decreased. Assuming the original threshold is 5A, and it is adjusted to 7A during peak electricity consumption periods, if the current parameter obtained at this time is 6A, since 6A is less than 7A, the purely resistive load mode is selected.

[0087] By clarifying the specific comparison method for determining the target load mode based on transmission line current parameters, a clear and operable judgment standard is provided for the selection of load mode, making the method more deterministic and practical. It can more accurately select the appropriate load mode according to different current conditions, further optimize the energy harvesting process, and improve energy harvesting efficiency and stability.

[0088] Based on the above embodiments, when the target load mode is a purely resistive load mode, the method described in S103 for adjusting the impedance characteristics of the adjustable electronic load in the UAV wireless power harvesting control device and the excitation parameters of the power harvesting core in the UAV wireless power harvesting control device according to the target load mode may include: determining the target resistance value corresponding to the maximum power harvesting based on the equivalent circuit model of the power harvesting core; controlling the adjustable electronic load to operate in a purely resistive mode and adjusting the resistance value of the adjustable electronic load to the target resistance value so that the excitation parameters of the power harvesting core operate in the maximum power power harvesting state.

[0089] In this embodiment, the equivalent circuit model of the energy-harvesting core can be used to facilitate analysis and calculation, representing the electromagnetic characteristics of the energy-harvesting core in actual operation as a circuit model composed of components such as resistors and inductors. This model can simulate the electrical behavior of the energy-harvesting core under different current, magnetic field, and other conditions, and may include, for example, resistive elements representing core losses and inductive elements reflecting the magnetic characteristics of the core.

[0090] The target resistance value can be the resistance value that the adjustable electronic load should possess, calculated based on the equivalent circuit model of the energy harvesting core, while pursuing maximum energy harvesting power. This value is closely related to the electromagnetic characteristics of the energy harvesting core and the parameters of other components in the equivalent circuit model.

[0091] Pure resistive mode refers to the operating mode in which the adjustable electronic load exhibits only resistive characteristics, with its current and voltage in phase, and without the participation of other reactive characteristics such as inductance and capacitance.

[0092] In some examples, the target resistance value that can achieve the maximum energy harvesting power can be determined by using the equivalent circuit model of the energy harvesting core, circuit theory and related calculation methods. Then, the adjustable electronic load is controlled to enter the pure resistive mode, and the resistance value of the adjustable electronic load is adjusted to the previously determined target resistance value through the adjustment mechanism or control circuit, so that the excitation parameters of the energy harvesting core can reach the state of maximum power energy harvesting.

[0093] One approach is to perform precise calculations based on the parameters of each component in the equivalent circuit model of the power harvesting core, using circuit theories such as the maximum power transfer theorem. For example, if the equivalent circuit model is a simple circuit containing a power source, resistor, and inductor, the maximum power transfer is achieved when the load resistance equals the internal resistance of the power source, thus determining the target resistance value. The microcontroller then controls the adjustable electronic load to adjust to this resistance value. Alternatively, the target resistance value can be determined through experimental testing. For instance, experiments can be conducted on an actual UAV wireless power harvesting control device, gradually changing the resistance value of the adjustable electronic load while monitoring the power harvesting. The resistance value corresponding to the maximum power harvesting is recorded and used as the target resistance value. In subsequent control, the adjustable electronic load is adjusted according to the experimentally obtained target resistance value.

[0094] By clarifying how to determine and adjust the resistance value of the adjustable electronic load based on the equivalent circuit model of the energy harvesting core in a purely resistive load mode to achieve maximum power harvesting, energy harvesting control can be made more precise and scientific, thereby improving the power and efficiency of wireless energy harvesting for UAVs.

[0095] Based on the above embodiments, the method for determining the target resistance value corresponding to the maximum energy harvesting power based on the equivalent circuit model of the energy harvesting core may include: obtaining the actual excitation parameters of the energy harvesting core by conducting an no-load test on the energy harvesting core; constructing an equivalent circuit model of the energy harvesting core based on the actual excitation parameters; establishing a functional relationship between the energy harvesting power and the load resistance based on the equivalent circuit model; performing a derivative operation on the functional relationship to obtain the load resistance value that maximizes the energy harvesting power, and using the load resistance value as the target resistance value.

[0096] The no-load test refers to an experiment conducted without connecting an adjustable electronic load, meaning the energy harvesting core is in a state where it is not drawing electrical energy under any actual load. The no-load test eliminates the influence of the load on the energy harvesting core, allowing for a purer acquisition of the core's characteristic parameters.

[0097] Actual excitation parameters refer to the relevant parameters exhibited by the energy harvesting core under the influence of a magnetic field during no-load experiments, such as excitation current, permeability, and core loss. These parameters reflect the electromagnetic properties and energy conversion characteristics of the energy harvesting core.

[0098] A functional relationship refers to the mathematical correspondence between the extracted power and the load resistance, which is usually described by a functional expression, for example... ,in, To extract power, Let represent the load resistance. Differentiation is used to study the rate of change of the function. By differentiating the functional relationship between the extracted power and the load resistance, the trend of the function can be found, and thus the load resistance value that maximizes the extracted power can be determined.

[0099] In some embodiments, the energy harvesting core is disconnected from the adjustable electronic load, and the parameters of the energy harvesting core under no-load conditions are measured using specialized measuring instruments to obtain the actual excitation parameters. Based on the obtained actual excitation parameters and combined with circuit theory knowledge, an equivalent circuit model that can accurately simulate the electromagnetic characteristics of the energy harvesting core is constructed (such as the model including the converted iron loss resistance value and the converted excitation reactance value). On the basis of the constructed equivalent circuit model, the intrinsic relationship between the energy harvesting power and the load resistance is analyzed, and a functional relationship between the energy harvesting power and the load resistance is established. The established functional relationship is calculated using mathematical differentiation to find the load resistance value that maximizes the energy harvesting power, and this value is taken as the target resistance value.

[0100] For example, in an unloaded experiment, high-precision current and voltage sensors are used to acquire parameters such as the actual excitation current and voltage of the energy-harvesting core. Then, based on these parameters, the equivalent circuit model of the energy-harvesting core is assumed to be a combined model including resistance, inductance, and an ideal transformer. A functional relationship between the harvested power and the load resistance is established using circuit analysis methods, for example, by deriving the functional expression using Kirchhoff's laws and power calculation formulas. Finally, the derivative of this function is calculated using mathematical software to obtain the target resistance value. Optionally, multiple unloaded experiments under different conditions can be conducted to obtain multiple sets of actual excitation parameters. Multiple approximate equivalent circuit models are constructed based on these parameters, and the functional relationship between the harvested power and the load resistance is fitted using experimental data. The derivative of the fitted function is then calculated to determine the target resistance value. For example, by changing experimental conditions such as temperature and magnetic field strength, data under different conditions can be obtained to make the fitted function closer to the actual situation.

[0101] In one example, Figure 2 The structural schematic diagram of the equivalent circuit model provided in this application is as follows: Figure 2As shown, this model can be an equivalent circuit model of a current transformer (CT) referred to the secondary side, used for analyzing and calculating the current from the primary side. Output voltage to the secondary side The entire physical process of power generation can be divided into three parts: the primary side (transmission line side), the core excitation branch, and the secondary side (load side). The primary side parameters are as follows: This refers to the primary side current referred to the secondary side. Core excitation branch parameters: The excitation inductance of the energy-harvesting core is referred to the secondary side and is used to represent the core's ability to establish a magnetic field. The iron loss resistance referred to the secondary side represents the energy loss of the iron core due to hysteresis and eddy current losses in an alternating magnetic field. Secondary side parameters: VSR characterizes the variable parallel branch (which can correspond to an adjustable electronic load; it is not a fixed resistor or capacitor, but a circuit whose impedance characteristics can be changed according to a control strategy). This represents the total secondary current. For capacitors; Equivalent resistance; This is the secondary side output voltage. When the adjustable electronic load connected in parallel with the energy-harvesting iron core is a purely resistive load, When the capacitive reactance is infinite, then The value is 0; when the adjustable electronic load connected in parallel to the energy-harvesting iron core is a resistive-capacitive load, it is adjusted by... The capacitive reactance value can produce It is used to change the excitation state (magnetic induction intensity) of the iron core.

[0102] Furthermore, when the adjustable electronic load connected in parallel to the energy-harvesting core is a purely resistive load, the energy harvesting power can be expressed as:

[0103] ;

[0104] By differentiating it, we can obtain the size of the purely resistive load corresponding to the maximum energy extraction power:

[0105] ;

[0106] in, Energy harvesting power / W; The secondary side energy extraction voltage / V of the energy extraction core; , , These are the equivalent impedance, reactance, and resistance (Ω) of the secondary side, respectively. The effective value of the primary side current of the energy extraction core is given in A. This is the turns ratio of the primary winding to the secondary winding; The converted iron loss resistance value is in Ω. The converted magnetizing reactance value is expressed in Ω.

[0107] It should be noted that the load resistance In the range When the load resistance increases, the output power increases; when it is in the range... When the load resistance increases, the output power will decrease. When the load resistance approaches infinity, it is equivalent to an open circuit on the secondary side, and the output power is approximately 0.

[0108] By obtaining actual parameters through no-load experiments, constructing models, establishing functional relationships, and performing derivative calculations, the determination of the target resistance value becomes more scientific and accurate. This helps to further optimize the adjustment of the adjustable electronic load, improve the efficiency and power of the UAV's wireless power harvesting, and ensure that the UAV obtains a more stable and sufficient energy supply during mission execution.

[0109] Based on the above embodiments, when the target load mode is a resistive-capacitive load mode, the method described in S103 for adjusting the impedance characteristics of the adjustable electronic load in the UAV wireless power harvesting control device and the excitation parameters of the power harvesting core in the UAV wireless power harvesting control device according to the target load mode may include: determining the target capacitive reactance value based on the constant power power harvesting requirement; controlling the adjustable electronic load to work in resistive-capacitive mode, and adjusting the capacitive reactance value of the adjustable electronic load to the target capacitive reactance value so that the excitation parameters of the power harvesting core work in a constant power power harvesting state.

[0110] The constant power demand refers to the requirement that the drone's devices can obtain electrical energy from power lines at a relatively stable power during operation to meet the power needs of various devices on the drone for stable operation. This requirement is to ensure that the drone's normal functions are not affected by fluctuations in power extraction during missions, such as maintaining stable image acquisition and data transmission during inspections.

[0111] The target capacitive reactance value is the value that the adjustable electronic load should possess in resistive-capacitive mode, based on the constant power extraction requirement. This value is related to factors such as the characteristics of the extraction core, the current parameters of the transmission line, and the specific requirements of constant power. The aim is to ensure that the excitation parameters of the extraction core reach a constant power extraction state. Furthermore, this value is used to compensate for the excitation reactance of the extraction core and to shunt the secondary current, so as to maintain a constant power output when the transmission line current is large. By controlling the capacitive reactance, the magnetic induction intensity is adjusted, thereby achieving constant power.

[0112] The RC mode refers to the operating mode in which an adjustable electronic load exhibits both resistive and capacitive characteristics. In this mode, there is a certain phase difference between the load current and voltage, and its impedance is composed of both resistance and capacitive reactance.

[0113] In this embodiment, a mathematical model for constant power harvesting can be established based on circuit theory and the electromagnetic characteristics of the power harvesting core. Through mathematical calculations, the target capacitive reactance range that meets the constant power harvesting requirement is initially determined. Then, experiments are conducted on an actual UAV wireless power harvesting control device, gradually adjusting the capacitive reactance value of the adjustable electronic load and observing the changes in harvested power to ultimately determine the precise target capacitive reactance value. For example, the target capacitive reactance value may be calculated to be within a certain range, and then fine-tuned within that range through experiments to find the capacitive reactance value that makes the harvested power most stable.

[0114] Intelligent control algorithms, such as fuzzy control or neural network control, can also be employed. During UAV operation, the deviation between the harvested power and the constant power demand is monitored in real time. Based on the deviation, the intelligent control algorithm automatically adjusts the capacitive reactance of the adjustable electronic load, gradually bringing it closer to the target capacitive reactance value to achieve constant power harvesting. For example, when the harvested power is detected to be lower than the constant power demand, the intelligent control system automatically increases the capacitive reactance of the adjustable electronic load, and vice versa.

[0115] In one example, when the adjustable electronic load connected in parallel with the energy-harvesting core (such as an energy-harvesting CT) is a resistive-capacitive load, the secondary-side energy-harvesting voltage and energy-harvesting power can be expressed as follows:

[0116] ;

[0117] ;

[0118] when At this time, the capacitive reactance is entirely used to compensate for the magnetizing reactance. As the absolute value of the capacitive reactance increases, the magnetic induction intensity of the harvesting CT will increase, thereby increasing the secondary voltage of the harvesting CT; when At this time, part of the capacitive reactance is used to compensate for the magnetizing reactance, and the remaining part will have a certain shunt effect on the secondary side current. As the absolute value of the capacitive reactance increases, the magnetic induction intensity of the energy-harvesting CT decreases, reducing its secondary side voltage; when... At this time, the capacitor and the magnetizing inductor resonate in parallel, and the circuit exhibits purely resistive behavior externally. The capacitive reactance exactly compensates for the magnetizing reactance, and the current flowing through the capacitive reactance is equal to the current flowing through the magnetizing reactance. Under parallel resonance, the magnetic flux density inside the energy-collecting CT is at its maximum, and the secondary voltage at this time is:

[0119] ;

[0120] in, The load resistance value (in Ω) of the adjustable electronic load when it behaves as a resistive-capacitive load.

[0121] By determining and adjusting the capacitive reactance value of the adjustable electronic load based on the constant power power demand, the power harvesting control can more accurately meet the constant power power harvesting requirements of the UAV, which helps to improve the stability and reliability of the UAV's wireless power harvesting.

[0122] Therefore, based on the energy harvesting characteristics analyzed above, energy harvesting control strategies can be established for different operating conditions: that is, based on the resistive-capacitive characteristics of the electronic load, control can be implemented under low current conditions in the transmission line. (i.e., the target load mode is a purely resistive load mode), to achieve maximum power extraction; when the transmission line current is large, control... (That is, the target load mode is resistive-capacitive load mode), to achieve constant power energy extraction. The device can be connected to an adjustable electronic load through a voltage conversion module such as a BUCK circuit to adjust the DC voltage obtained from energy extraction to the input voltage required by the UAV.

[0123] The above embodiments address the issue of energy harvesting efficiency fluctuations caused by transmission line current fluctuations through operating condition judgment and load switching mechanisms. Specifically, under low-current conditions, the optimal resistance value calculation of the purely resistive load ensures maximum energy harvesting power; under high-current conditions, capacitive reactance compensation of the resistive-capacitive load avoids magnetic flux saturation caused by excessive excitation reactance, maintaining constant output power. This dynamic adjustment mechanism adapts to different operating conditions, enabling the device to operate stably even during sudden changes in transmission line current, thus improving the continuity and adaptability of the UAV's endurance.

[0124] Existing wireless charging solutions mostly employ electromagnetic induction or magnetic resonance technology, requiring precise alignment of the transmitting and receiving coils, and suffer from low energy extraction efficiency. Although the above embodiments can solve the problem of low energy extraction efficiency, existing wireless charging requires precise alignment of the coils during power transmission, which not only limits the drone's freedom of movement but is also susceptible to environmental interference (such as wind speed and vibration) in practical applications, resulting in energy loss and thus affecting energy extraction efficiency.

[0125] Therefore, to address the problem of low energy harvesting efficiency caused by the strict alignment of coils required in traditional wireless charging, this embodiment, based on the above embodiments, further includes a wireless power transmission module in the drone wireless power harvesting control device. After controlling the drone wireless power harvesting control device to output a stable DC voltage according to the adjusted excitation parameters and impedance characteristics, the method may further include: driving the wireless power transmission module to work based on the stable DC voltage; determining the transmission efficiency parameters of the wireless power transmission module based on the coupling state between the transmitting coil and the receiving coil in the wireless power transmission module; and dynamically adjusting the circuit parameters of the wireless power transmission module according to the transmission efficiency parameters to make the wireless power transmission module operate in a parity-time symmetrical state.

[0126] In this embodiment, the wireless power transmission module can be a functional module in the UAV's wireless power acquisition and control device, mainly used to realize the wireless transmission of electrical energy. It uses principles such as electromagnetic induction and magnetic resonance to wirelessly transmit the electrical energy acquired and converted by the power acquisition device to other electrical devices or energy storage devices of the UAV.

[0127] The transmitting coil can be a component in a wireless power transmission module used to generate an alternating magnetic field. When current flows through it, it generates a changing magnetic field. The receiving coil is placed at the end of the device that needs to receive electrical energy (such as a drone). It generates an induced electromotive force in the changing magnetic field through the principle of electromagnetic induction, thereby realizing the wireless reception of electrical energy.

[0128] Coupling states can be used to describe the degree and characteristics of magnetic field interaction between transmitting and receiving coils, including parameters such as the coupling coefficient. The coupling coefficient reflects the degree of magnetic flux coupling between the two coils, and its value affects the efficiency and power of wireless power transmission.

[0129] Transmission performance parameters can be used to measure the effectiveness of a wireless power transfer module in transmitting electrical energy. Examples include the module's operating efficiency, output power, or the coupling coefficient value obtained through a coupling coefficient estimation model. These parameters directly reflect the energy transmission from the transmitting coil to the receiving coil. Operating efficiency, in particular, can be determined based on the equivalent series resistance and load resistance of the transmitting-side resonant network within the wireless power transfer module.

[0130] In the field of wireless power transfer, parity-time (PT) symmetry refers to a special state that simultaneously satisfies parity symmetry (spatial reflection symmetry) and time reversal symmetry. When a wireless power transfer module operates in a PT-symmetric state, it possesses unique properties, such as achieving efficient energy transfer, good stability, and strong anti-interference capabilities.

[0131] In some embodiments, after outputting a stable DC voltage, this stable DC voltage is used to power the wireless power transfer module, driving it to start working. By detecting parameters such as current and voltage between the transmitting and receiving coils and combining them with relevant calculation formulas, the transmission efficiency parameters of the wireless power transfer module, such as the coupling coefficient between the transmitting and receiving coils, are determined. Based on the determined transmission efficiency parameters, the control unit automatically adjusts the circuit parameters in the wireless power transfer module, such as the values ​​of components like capacitors, inductors, and resistors, to make the module reach and maintain a PT symmetrical operating state. Further optionally, the wireless power transfer module may include detection devices such as current sensors and voltage sensors to monitor the current and voltage values ​​of the transmitting and receiving coils in real time. The microcontroller in the UAV wireless power harvesting control device calculates the transmission efficiency parameters, such as transmission efficiency, based on the detected data. Then, the microcontroller automatically adjusts the parameters of components such as variable capacitors and inductors in the module according to a preset algorithm and the target PT symmetrical state requirements. For example, when the transmission efficiency is lower than a set value, the microcontroller adjusts the capacitance value of the variable capacitor to improve the coupling state, increase the transmission efficiency, and make the module approach a PT symmetrical operating state.

[0132] Optionally, in some examples, the wireless power transfer module may include a Class E power amplifier, a transmitter-side resonant network, and a receiver-side resonant network, wherein the transmitter-side resonant network includes a transmitter coil, and the receiver-side resonant network includes a receiver coil. A stable DC voltage is supplied to the Class E power amplifier of the wireless power transfer module; a high-frequency AC signal is generated by the Class E power amplifier to drive the transmitter coil to generate an alternating magnetic field; by adjusting the resonator parameters of the wireless power transfer module, the transfer module operates in the parity-time symmetric region under the current coil coupling coefficient, thereby achieving alignment-free and efficient power transfer.

[0133] By adding a wireless power transfer module to the device, the wireless power harvesting and control functionality of the UAV is further improved. By driving the wireless power transfer module and determining the transmission efficiency parameters based on the coupling state, and then dynamically adjusting the circuit parameters to maintain a PT-symmetrical operating state, this method can maintain high-efficiency transmission even when the transmission efficiency parameters vary (e.g., the UAV deviates from the coil center), significantly reducing alignment dependence. Simultaneously, the high efficiency of the Class E power amplifier reduces switching losses, adapting to the dynamic flight scenarios of the UAV and effectively improving the transmission efficiency, stability, and reliability during wireless power harvesting.

[0134] Based on the above embodiments, a method for dynamically adjusting the circuit parameters of a wireless power transmission module according to transmission performance parameters to make the wireless power transmission module operate in a parity-time symmetric state may include: determining whether the wireless power transmission module is operating in a parity-time symmetric state based on the transmission performance parameters; if the wireless power transmission module is not operating in a parity-time symmetric state, then dynamically adjusting the switching frequency of the Class E power amplifier in the wireless power transmission module, and / or the resonant parameters of the transmitting coil and the receiving coil, to make the wireless power transmission module operate in a parity-time symmetric state.

[0135] In this embodiment, the Class E power amplifier can be a high-efficiency switch-mode power amplifier. During operation, its switching elements ideally switch between fully on and fully off states, thereby reducing power loss and improving energy conversion efficiency. It is commonly used in scenarios with high efficiency requirements, such as wireless power transmission. For a Class E power amplifier, the switching frequency refers to the number of times its switching elements switch between on and off per unit time. The setting of the switching frequency affects the amplifier's output characteristics and performance indicators such as the efficiency of wireless power transmission. Resonant parameters refer to the parameters of components such as inductors and capacitors in the resonant circuit composed of the transmitting and receiving coils. These parameters determine the resonant frequency and other characteristics of the resonant circuit, and whether the resonant frequency is matched has a significant impact on the efficiency and quality of wireless power transmission.

[0136] In some examples, based on acquired transmission performance parameters, such as transmission efficiency and power fluctuation, and according to a pre-defined parity-time (PT) symmetrical operating state criterion, it can be determined whether the wireless power transmission module is currently in a PT symmetrical operating state. If the determination result indicates that the wireless power transmission module is not in a PT symmetrical operating state, it can be adjusted in two ways or a combination of both. First, dynamically adjust the switching frequency of the Class E power amplifier to change its output characteristics and affect the overall performance of the wireless power transmission. Second, adjust the resonant parameters of the transmitting and receiving coils to make the operating state of the resonant circuit closer to the ideal condition, thereby enabling the wireless power transmission module to achieve a PT symmetrical operating state.

[0137] In one example, a feedback control system can be incorporated into the wireless power transfer module. This system monitors transmission performance parameters in real time and makes judgments based on preset PT symmetry criteria. If the module is detected to be operating outside of PT symmetry, the feedback control system automatically adjusts the switching frequency of the Class E power amplifier and, as needed, adjusts the resonant parameters of the transmitting and receiving coils. For example, a microcontroller calculates the required switching frequency increment and resonant parameter change based on real-time data and then drives the corresponding adjustment circuitry until the module achieves PT symmetry.

[0138] In another example, the transmission performance parameters can be segmented based on experience or experimental data, and a corresponding adjustment strategy can be set for each segment. When the module is not in a PT-symmetrical operating state, the switching frequency of the Class E power amplifier is first adjusted according to the preset segmented adjustment strategy to observe the changes in the transmission performance parameters. If the effect is not significant, the resonant parameters of the transmitting and receiving coils are then adjusted. During the adjustment process, the operator can also monitor the adjustment status in real time through the monitoring interface and make manual interventions when necessary, such as manually adjusting the initial values ​​of certain parameters.

[0139] By determining whether the wireless power transmission module is in a PT symmetrical working state, and adjusting preset parameters to bring it to that state when it is not, the performance of the wireless power transmission module can be optimized more accurately, further improving the efficiency and stability of wireless power acquisition. This ensures that the UAV obtains a more reliable and efficient power supply during wireless power acquisition, and enhances the adaptability and reliability of the UAV wireless power acquisition control device.

[0140] Based on the above embodiments, the transmission performance parameter is the coupling coefficient between the transmitting coil and the receiving coil. A method for determining whether the wireless power transmission module is in a parity-time symmetric operating state based on the transmission performance parameter may include: comparing the coupling coefficient with a critical coupling coefficient, where the critical coupling coefficient is constructed based on the equivalent series resistance, load resistance, inherent operating angular frequency of the resonator, and inductance of the receiving resonator in the wireless power transmission module's receiving-side circuit; if the coupling coefficient is greater than or equal to the critical coupling coefficient, the wireless power transmission module is in a parity-time symmetric operating state; if the coupling coefficient is less than the critical coupling coefficient, the wireless power transmission module is not in a parity-time symmetric operating state.

[0141] In this embodiment, the coupling coefficient can be a physical quantity that measures the tightness of the magnetic field coupling between the transmitting coil and the receiving coil, typically expressed as... The larger the coupling coefficient, the tighter the magnetic field coupling between the two coils, and the higher the energy transfer efficiency is usually; conversely, the looser the coupling, the lower the energy transfer efficiency may be. The critical coupling coefficient is a key threshold constructed based on some characteristic parameters of the receiving-side circuit (such as the receiving-side resonant network) in the wireless power transfer module. It comprehensively considers factors such as the equivalent series resistance of the receiving-side circuit, the load resistance, the inherent operating angular frequency of the resonator, and the inductance of the receiving-side resonator, and is used to determine whether the wireless power transfer module is in a PT symmetrical operating state.

[0142] In the receiving-side circuit, various resistive losses can be equivalent to a resistor connected in series in the circuit (i.e., equivalent series resistance). It reflects the energy loss in the circuit due to factors such as coil internal resistance and line resistance, in addition to the load resistance.

[0143] Load resistance refers to the resistance exhibited by the device or circuit that actually consumes electrical energy, connected to the receiving end of the wireless power transfer module. It is the final destination of electrical energy transmission, and its magnitude affects the absorption and utilization of electrical energy at the receiving end.

[0144] The resonator can be a key component in a resonant circuit composed of a transmitting coil and a receiving coil. Its inherent operating angular frequency is the angular frequency of the resonator's oscillation when there is no external interference; it is typically expressed as... This indicates that it is related to the inductance and capacitance in the resonant circuit, such as... ,in, For inductance, It is a capacitor.

[0145] In some embodiments, the critical coupling coefficient can be calculated using a specific mathematical formula based on parameters such as the equivalent series resistance, load resistance, inherent operating angular frequency of the resonator, and inductance of the receiving resonator in the wireless power transmission module. Then, the calculated critical coupling coefficient is compared with the actual measured coupling coefficient between the transmitting and receiving coils.

[0146] In one example, by coordinating the parameters of the Class E power amplifier with those of the resonator, the wireless power transfer module can operate at a parity-time symmetry point with a specific coupling coefficient. The parity-time symmetry region and the broken region of the module are defined based on the magnitude of the coupling coefficient between the primary and secondary coils; specifically, when the coupling coefficient is greater than or equal to the critical coupling coefficient... At that time, the module is in the symmetry region (i.e., the wireless power transmission module is in a parity-time symmetric operating state), when the coupling coefficient is less than At that time, the module is in the broken region (i.e., the wireless power transmission module is not in a parity-time symmetric operating state). Determined in the following ways:

[0147] ;

[0148] in, The equivalent series resistance of the receiving side circuit. For load resistance, The natural operating angular frequency of the harmonic oscillator. For the receiving side resonator inductor.

[0149] At the symmetrical operating point, the module's efficiency can maintain a large and stable value, the specific value of which can be determined in the following way:

[0150] ;

[0151] in, This is the equivalent series resistance of the transmitter-side circuit (such as a transmitter-side resonant network). Since the equivalent series resistance of the circuit is much smaller than the load resistance, the system can maintain a relatively high operating efficiency.

[0152] By using the coupling coefficient as a transmission efficiency parameter and further dynamically adjusting the wireless power transmission module and resonant frequency, the problem of strict coil alignment required in traditional wireless charging is solved. This allows the module to maintain efficient transmission even within the range of coupling coefficient variations (such as when the drone deviates from the coil center), reducing alignment dependence and ensuring that the wireless power transmission module is always in a highly efficient and stable working state, thereby improving the reliability and performance stability of the drone's wireless power harvesting control device.

[0153] Correspondingly, when the transmission performance parameter is the coupling coefficient between the transmitting and receiving coils, if the wireless power transmission module is not operating in a parity-time symmetrical state, the resonant frequency of the high-frequency AC signal can be adjusted based on the coupling coefficient. The high-frequency AC signal can be generated by a Class E power amplifier. Further, the adjustment method can include at least one of the following: when the coil spacing increases, the resonant frequency is adjusted to a high-frequency mode (which can refer to an operating state where the resonant frequency is in a higher range, typically used to compensate for a low coupling coefficient, such as increasing the resonant frequency from 100kHz to 200kHz) to compensate for the decrease in the coupling coefficient; when the coil spacing decreases, the resonant frequency is adjusted to a low-frequency mode (which can refer to an operating state where the resonant frequency is in a lower range, typically used to reduce switching losses, such as decreasing the resonant frequency from 200kHz to 100kHz) to reduce switching losses.

[0154] The resonant frequency is adaptively adjusted across multiple frequency bands: when the coil spacing increases, causing the coupling coefficient to decrease, the system switches to a high-frequency mode to enhance magnetic field penetration; when the coil spacing decreases, causing the coupling coefficient to increase, the system switches to a low-frequency mode to reduce switching losses. The resonant frequency adjustment can be achieved by the DSP control circuit driving the resonator parameters (such as capacitance values) of the Class E power amplifier, ensuring that the wireless power transfer module operates within its optimal efficiency range under different coupling coefficients.

[0155] Based on the above embodiments, the transmitting coil and receiving coil in the wireless power transmission module adopt a low-loss capacitor segmented compensation structure, which is constructed by dispersing and connecting multiple compensation capacitors in series in the coil conductor; the method may also include: controlling the wireless power transmission module to operate at the target resonant frequency based on the capacitor segmented compensation structure.

[0156] Low-loss capacitors refer to capacitors that exhibit minimal energy loss during circuit operation. Their losses primarily manifest as dielectric loss and conductor loss. During charging and discharging, low-loss capacitors convert a smaller proportion of electrical energy into heat or other forms of energy, enabling more efficient energy storage and release, and improving transmission efficiency.

[0157] The segmented capacitor compensation structure can adjust the inductor-capacitor resonance characteristics of the coil, improving circuit performance, such as increasing the stability of the resonant frequency and enhancing power transmission efficiency. Furthermore, the segmented capacitor compensation structure can form multi-band resonator parameters, that is, by switching multiple capacitor / inductor combinations configured in the transmitting and receiving coils to support different resonant frequencies.

[0158] The target resonant frequency can be the resonant frequency that the resonant circuit composed of the transmitting and receiving coils in the wireless power transmission module is expected to reach. At this frequency, the circuit can achieve efficient energy transmission and good performance. The specific value can be determined based on factors such as the power requirements of the UAV and the distance of wireless power transmission. Multiple target resonant frequencies may be included.

[0159] Furthermore, in the transmitting and receiving coil conductors of the wireless power transmission module, multiple low-loss compensation capacitors are pre-connected in series in a distributed manner according to certain rules and layouts. For example, Figure 3 This is a connection diagram of the capacitor segment compensation structure provided in this application, as shown below. Figure 3 As shown, multiple capacitors are distributed in series within the resonant coil. A group of concentrated capacitors is connected in series at intervals along the coil length. Each concentrated capacitor and the distributed inductance resonate in series at the operating frequency, thereby reducing the potential difference between the coil turns, eliminating the large electric field between the coil turns, and thus significantly reducing the dielectric loss of the resonant coil. In practical applications of the coil conductor, the specific connection structure is as follows: Figure 4 As shown.

[0160] Accordingly, based on the capacitor segment compensation structure, the method for controlling the wireless power transmission module to operate at the target resonant frequency may further include: controlling each segment of distributed inductance and its series-connected concentrated capacitor in the transmitting coil and receiving coil to resonate in series at the target resonant frequency.

[0161] By employing a segmented capacitor compensation structure in both the transmitting and receiving coils, the control module operates at the target resonant frequency. This optimizes the resonant characteristics of the coils within the module, reduces energy loss during transmission, improves the efficiency and stability of wireless power transmission, and ensures the reliability and efficiency of the UAV during power acquisition.

[0162] However, a large number of series-connected resonant capacitors introduce more solder joints to the resonator. Under high-frequency operating conditions, the increase in solder joints will in turn increase the resonator loss of the wireless power transmission module. Therefore, based on the above embodiments, before controlling the wireless power transmission module to operate at the target resonant frequency based on the capacitor segment compensation structure, the method may further include: obtaining a distributed parameter simulation model of the transmitting coil and / or receiving coil in the wireless power transmission module, wherein the distributed parameter simulation model is constructed based on an electromagnetic field simulation tool; and optimizing the number and position of the compensation capacitors in the capacitor segment compensation structure based on the distributed parameter simulation model to determine a capacitor segment compensation scheme that meets the preset loss conditions at the target resonant frequency.

[0163] In this embodiment, the distributed parameter simulation model can refer to a model built based on electromagnetic field simulation tools, used to describe the electrical characteristics of the transmitting coil and / or receiving coil in the wireless power transmission module. This model considers the spatial distribution of electromagnetic energy and can more accurately reflect the changes in parameters such as voltage, current, and magnetic field at different locations of the coil, providing a more precise basis for analyzing and optimizing coil performance.

[0164] Electromagnetic field simulation tools are software tools that use computer technology to simulate and analyze electromagnetic field distribution and electromagnetic phenomena, such as ANSYS Maxwell and COMSOL. They can calculate the distribution of the electromagnetic field based on parameters such as the coil's geometry, material properties, and excitation source, and thus obtain various electrical parameters of the coil, such as inductance, capacitance, and resistance.

[0165] Preset loss conditions are limitations on energy loss that are set in advance when designing a wireless power transfer module. These conditions can be determined according to the actual application scenario and requirements. For example, it may be stipulated that the total energy loss of the wireless power transfer module at the target resonant frequency must be minimum or must not exceed a certain percentage, or that the power loss of the transmitting and receiving coils must not exceed a specific value.

[0166] The segmented capacitor compensation scheme, based on the determined segmented compensation structure and optimization analysis results, specifies the number, location, and capacitance values ​​of the compensation capacitors. This scheme aims to ensure the wireless power transfer module meets preset loss conditions at the target resonant frequency, achieving efficient power transfer.

[0167] In some examples, electromagnetic field simulation tools can be used to construct and obtain a distributed parameter simulation model of the transmitting and / or receiving coils in the wireless power transfer module, based on information such as the actual geometry, material properties, and winding method. Based on the obtained distributed parameter simulation model, a comprehensive optimization analysis is performed on the number and location of compensation capacitors in the segmented capacitor compensation structure. By changing the number and location of the compensation capacitors, the performance of the wireless power transfer module under different schemes at the target resonant frequency is simulated, particularly regarding energy loss. Based on the results of the optimization analysis and combined with preset loss conditions, a segmented capacitor compensation scheme that meets the requirements at the target resonant frequency is determined, i.e., the specific number, location, and appropriate capacitance values ​​of the compensation capacitors are determined. For example, by establishing a COMSOL simulation model to analyze the loss of the distributed capacitor size and number, a segmented capacitor compensation design under optimal power consumption can be achieved.

[0168] Alternatively, a multi-parameter scanning optimization method can be used: In an electromagnetic field simulation tool, the range of variation for the number and location of compensation capacitors, as well as the scanning step size, are set. Then, the simulation tool performs multiple simulation calculations according to the set parameters, changing the combination of the number and location of the compensation capacitors in each calculation. By comparing the loss data of the wireless power transfer module at the target resonant frequency under different combinations, the optimal capacitor segmentation compensation scheme that meets the preset loss conditions is found. For example, the number of compensation capacitors can range from 2 to 10, with different intervals where they are uniformly distributed on the coil conductor, for scanning analysis.

[0169] Alternatively, optimization can be based on a combination of intelligent algorithms and electromagnetic field simulation tools. For example, intelligent algorithms such as genetic algorithms and particle swarm optimization algorithms can be combined with electromagnetic field simulation tools. The intelligent algorithm automatically adjusts the number and location parameters of the compensation capacitors based on the loss data fed back from the simulation tool, continuously iterating and optimizing until the optimal capacitor segmentation compensation scheme that meets the preset loss conditions is found. For instance, a genetic algorithm, by simulating selection, crossover, and mutation operations in biological evolution, gradually selects better parameter combinations.

[0170] By optimizing the number and location of compensation capacitors in the segmented capacitor compensation structure, the energy loss of the wireless power transmission module during power transmission can be reduced, providing more stable and efficient wireless power harvesting support for drones.

[0171] This application also provides a wireless power harvesting control device for unmanned aerial vehicles (UAVs), including a power harvesting core, an adjustable electronic load, a signal detection circuit, a BUCK circuit, and a DSP control circuit. The power harvesting core is sleeved on a power transmission line for coupling and harvesting AC power. The input terminal of the adjustable electronic load is connected to the secondary winding of the power harvesting core, and the output terminal of the adjustable electronic load is connected to the input terminal of the BUCK circuit. The adjustable electronic load is used to adjust the equivalent impedance based on a control signal, and the BUCK circuit is used to output a stable DC voltage. The input terminal of the signal detection circuit is connected to the secondary winding and / or the BUCK circuit. The signal detection circuit is used to acquire the power transmission line current parameters. The output terminal of the signal detection circuit is connected to the input terminal of the DSP control circuit, and the output terminal of the DSP control circuit is connected to the control terminal of the adjustable electronic load. The DSP control circuit is used to execute the above-described... Figure 1 The method of the embodiment and some embodiments of the method.

[0172] In this embodiment, the energy harvesting core is an iron core made of a magnetic material with high permeability, typically in the form of a ring or other shape suitable for being fitted onto a power transmission line. It can couple with the alternating magnetic field in the power transmission line, thereby inducing alternating current in the secondary winding and providing an energy source for the drone's wireless power harvesting.

[0173] An adjustable electronic load is an electronic device whose equivalent impedance can be adjusted via an external control signal. In a drone's wireless power harvesting control device, it is connected between the secondary winding of the power harvesting core and the BUCK circuit. By changing the equivalent impedance, the electrical energy harvested from the power harvesting core can be adjusted to meet different operational requirements.

[0174] The signal detection circuit is used to acquire the current parameters of the transmission line. It can be connected to the secondary winding of the energy harvesting core and / or the BUCK circuit, converting the current signal into a processable electrical signal through components such as sensors, and transmitting it to the DSP control circuit. For example, the signal detection circuit may include voltage sensors and current sensors to monitor voltage and current, ensure that the device operates within safe ranges, and provide feedback signals to adjust the output.

[0175] A BUCK circuit, also known as a buck converter circuit, is a type of DC-DC converter. It steps down the input DC voltage to output a stable DC voltage, providing a suitable power supply for drones.

[0176] A DSP control circuit, or Digital Signal Processor control circuit, is a control system composed of a microprocessor and related circuits specifically designed for digital signal processing. It can send control signals to the adjustable electronic load based on the transmission line current parameters transmitted from the signal detection circuit, thereby achieving precise control of the energy harvesting process.

[0177] In some examples, the DSP control circuit can pre-store fixed control algorithms. Based on the transmission line current parameters received from the signal detection circuit, it calculates and outputs control signals to the adjustable electronic load according to set rules, adjusting its equivalent impedance. For example, when a large transmission line current is detected, the equivalent impedance of the adjustable electronic load is appropriately increased to reduce the energy drawn from the power extraction core and avoid overload. In other examples, the DSP control circuit can also have adaptive adjustment capabilities, capable of adjusting the control strategy in real time according to changes in the transmission line current. It continuously learns and analyzes the changing patterns of the current parameters, dynamically adjusting the equivalent impedance of the adjustable electronic load to keep the DC voltage output by the BUCK circuit stable. For example, when the transmission line current fluctuates significantly, the control parameters are automatically optimized to ensure the stability of the energy extraction process.

[0178] Figure 5 Schematic diagram of the structure of the UAV wireless power harvesting control device provided in this application Figure 1 ,like Figure 5 As shown, the goal of this device is to: regardless of the transmission line current Regardless of the changes, the impedance of the adjustable electronic load can be adjusted. Finally, a stable DC voltage is obtained at the output of the BUCK circuit. .in, It can refer to the actual impedance of the adjustable electronic load, such as Figure 2 The impedance in the VSR (Variable Parallel Branch) shown can be purely resistive or resistive-capacitive. It can refer to the target impedance of the adjustable electronic load, which can be calculated by the control circuit under the current operating conditions (e.g., (Size) The ideal impedance value that needs to be set to achieve a specific goal (maximum power or constant power).

[0179] The control circuit may include an impedance calculation module, a command current generation module, and QPR (quasi-proportional resonant controller) and SPWM (sinusoidal pulse width modulation) for control execution. The impedance calculation module uses the detected primary current... (The signal detection circuit is omitted here; no special restrictions are imposed, as long as it can acquire and detect parameters such as current and voltage.) Determine the target load mode; if... If the value is small, then the target resistance value corresponding to the maximum power point is calculated based on the equivalent circuit model, i.e. It is purely resistive; if If the value is large, then the required target capacitive reactance and resistance values ​​are calculated based on the constant power requirement, i.e. It is resistive-capacitive. The command current generation module is based on the secondary side voltage. and the calculated target impedance This yields a target current waveform that can be executed. To generate an instantaneous current command signal for presentation The impedance characteristics. Δ This is the current error signal, i.e., the target current waveform. Compared with the actual detected current The difference between the two currents. This current error signal, through the QPR controller, outputs a modulation signal, which, through SPWM, generates a series of high-frequency pulse waves with sinusoidally varying duty cycles. These pulses drive the switching transistors in the adjustable electronic load (typically fully controllable switching devices such as IGBTs or MOSFETs). By precisely controlling the on / off state of these switching transistors, the actual current can be forced... Closely follow the target current Thus, the target impedance is precisely achieved. .

[0180] A BUCK circuit, or DC-DC circuit, can control the output voltage through its internal PWM control, regardless of voltage fluctuations in its preceding stage (adjustable electronic load output). Stabilize at the target value This is to ensure that the voltage output to the drone is stable.

[0181] Alternatively, the SPWM and its subsequent drive section (such as the switching transistor) can be independent of the control circuit and serve as the switching transistor drive circuit in the device.

[0182] In some embodiments, the UAV wireless power harvesting control device may further include a full-bridge rectifier circuit. A full-bridge rectifier circuit is a circuit that converts alternating current (AC) to direct current (DC), consisting of four diodes connected in a specific bridge configuration. In this device, it can be connected between the secondary winding of the power harvesting core and the adjustable electronic load and BUCK circuit, converting the AC power coupled from the power harvesting core into unidirectional pulsating DC power, providing a suitable DC input for the subsequent adjustable electronic load and BUCK circuit. Further, after the power harvesting core is coupled onto the transmission line to harvest AC power, it transmits it to the full-bridge rectifier circuit. The full-bridge rectifier circuit converts the AC power into DC power and then outputs it to the input of the adjustable electronic load and BUCK circuit. Through the conversion by the full-bridge rectifier circuit, the availability of electrical energy can be improved, contributing to enhanced efficiency and stability of subsequent circuits.

[0183] Based on the above embodiments, the UAV wireless power harvesting control device further includes a wireless power transmission module; the input terminal of the wireless power transmission module is connected to the output terminal of the BUCK circuit, used to receive a stable DC voltage and wirelessly charge the UAV; the wireless power transmission module includes a Class E power amplifier, a transmitter-side resonant network, and a receiver-side resonant network, wherein the transmitter-side resonant network includes a transmitter coil, and the receiver-side resonant network includes a receiver coil; wherein the DSP control circuit is also used to execute some embodiments corresponding to the above methods.

[0184] In this embodiment, the wireless power transfer module can be a module that transmits electrical energy from the power source to the load through principles such as electromagnetic induction and magnetic field resonance without requiring a physical connection. In this device, it receives a stable DC voltage output from the BUCK circuit and converts it into an energy form suitable for wireless transmission to wirelessly charge the drone.

[0185] Class E power amplifiers, through special circuit design and switching operating modes, can convert input DC power into high-frequency AC power at higher frequencies, providing sufficient high-frequency power signals for subsequent wireless power transmission. Compared to traditional power amplifiers, Class E power amplifiers offer higher efficiency and lower power loss.

[0186] The transmitter-side resonant network mainly consists of a transmitting coil and associated capacitors. It efficiently radiates the high-frequency AC power output from the Class E power amplifier in the form of a magnetic field. Through resonance, it ensures the transmitting coil operates at its optimal frequency, improving energy transfer efficiency. The receiver-side resonant network, containing a receiving coil and corresponding capacitors, shares the same resonant frequency as the transmitter-side network. When the receiver-side resonant network is close to the transmitter-side resonant network, it efficiently receives the radiated magnetic field energy through magnetic resonance and converts it into electrical energy to charge the drone.

[0187] The transmitting and receiving coils are key components of wireless power transmission. The transmitting coil, in the transmitting-side resonant network, is responsible for converting electrical energy into magnetic field energy and transmitting it; the receiving coil, in the receiving-side resonant network, is responsible for receiving magnetic field energy and converting it into electrical energy. Their geometry, number of turns, materials, and other parameters directly affect the efficiency and distance of wireless power transmission.

[0188] In one example, the stable DC voltage output by the BUCK circuit is connected to the input of the wireless power transfer module. The Class E power amplifier in the module converts the DC power into high-frequency AC power, which is then emitted as a magnetic field through a transmitting-side resonant network (including a transmitting coil). The receiving-side resonant network (including a receiving coil) receives the magnetic field energy when close to the transmitting side and converts it into electrical energy to wirelessly charge the drone. Simultaneously, in addition to executing some embodiments of the above method, the DSP control circuit may also control the operating parameters of the wireless power transfer module to ensure the stability and efficiency of the wireless charging process. Optionally, the DSP control circuit can dynamically adjust the frequency of the wireless power transfer based on actual conditions, such as changes in the distance between the drone and the charging device, or changes in load. For example, when the drone is far from the charging device, the transmission frequency can be appropriately increased to enhance the radiation capability of the magnetic field, thereby increasing the transmission distance and efficiency.

[0189] It should be noted that the DSP control circuit that controls the wireless power transmission module can be a control circuit independent of other components, that is, the control part is divided into two control circuits to control the output of stable DC voltage and the transmission of electrical energy respectively.

[0190] Optionally, the receiver-side resonant network can be configured with multiple receiving coils distributed at different locations on the drone. This increases the area for receiving magnetic field energy, improving the efficiency and stability of wireless charging. For example, for some large drones, multiple receiving coils can be placed in different parts of the fuselage to ensure effective energy reception under different attitudes.

[0191] In some embodiments, the Class E power amplifier may optionally include a choke inductor, a switching transistor, a parallel capacitor for the switching transistor, and a residual inductor; one end of the choke inductor is connected to the output of the BUCK circuit, and the other end is connected to the drain of the switching transistor, one end of the parallel capacitor for the switching transistor, and one end of the residual inductor; the source of the switching transistor is grounded, and its gate is connected to a switching transistor driving circuit; the other end of the residual inductor is connected to the emitter-side resonant network.

[0192] Figure 6 A schematic diagram of the wireless power transmission module provided in this application is shown below. Figure 6 As shown, the wireless power transfer module is configured with an SS-type wireless power transfer topology, wherein the transmitter-side resonant network includes a transmitter-side inductor L. T Capacitor C T Coil internal resistance R T The receiver-side resonant network includes the receiver-side inductor L. R Capacitor C R Coil internal resistance R R and drone payload R L Class E power amplifiers include choke inductors Lf Switch S W The parallel capacitor (or resonant capacitor) C1 of the switching transistor and the residual inductance (or resonant inductance) L b .in, The DC input voltage is a stable DC voltage output from the front-end (BUCK circuit), which is the energy source for the entire wireless power transfer module; is the switching node voltage, which is the voltage between the drain (or collector) of the switching transistor and ground. This is a high-frequency square wave pulse voltage that determines the amplifier's operating efficiency; M is the mutual inductance, specifically the emitter-side inductance L. T With the receiving side inductor L R The physical quantities with varying degrees of coupling between them, optionally, , is the coupling coefficient.

[0193] Furthermore, in one example, the choke inductor L f One end of the choke inductor is connected to the BUCK circuit in the device, and the other end of the BUCK circuit is grounded. f The other end is connected to the switching transistor S. W The drain of the switch, one end of the parallel capacitor C1, and the residual inductance L b One end is connected to the switching transistor S. W The source terminals are connected in parallel with the other end of capacitor C1 and the remaining inductance L. b The other end is connected;

[0194] Furthermore, in this wireless power transmission module, the receiving coil inductance L R Receiver coil capacitance C R Load resistance R L and the internal resistance R of the receiving coil R They are connected in series to form a series circuit; choke inductor L f One end of the choke inductor is connected to the positive terminal of the DC power supply, and the negative terminal of the DC power supply is grounded. f The other end is connected to the switching transistor S. W The drain of the switch, one end of the parallel capacitor C1, and the residual inductance L b One end is connected to the switching transistor S. W The source terminals are connected in parallel with the other end of capacitor C1 and the internal resistance R of the transmitting coil, respectively. T One end is connected, and the remaining inductance L b The other end is connected to the transmitting coil capacitor C T One end is connected to the transmitting coil capacitor C. T The other end is connected to the transmitting coil inductance L T One end is connected, and the inductance of the transmitting coil is L. T The other end is connected to the internal resistance R of the transmitting coil. TThe other end is connected to the switching transistor S. W The gate of the transistor is connected to the output terminal of the switching transistor drive circuit.

[0195] Optionally, in some embodiments, the transmitting inductor L T Size and receiving inductance L R Equal in size, emitter capacitance C T Size and receiving capacitance C R They are the same size.

[0196] By rationally configuring and coordinating the components in this module, the stable DC voltage output by the BUCK circuit can be efficiently converted into a high-frequency AC voltage, and the energy can be transferred to the transmitting side resonant network through the residual inductor. This provides a high-quality high-frequency energy source for the drone's wireless power harvesting, enhances the stability of the drone's wireless power harvesting control device during the power harvesting process, and thus better meets the drone's wireless charging needs.

[0197] Based on the above embodiments, the transmitting coil and / or receiving coil employ a segmented capacitor compensation structure; wherein, the segmented capacitor compensation structure is constructed by distributing multiple compensation capacitors in series within the coil conductors, thereby reducing the dielectric loss of the coil. Based on this embodiment, the DSP control circuit is also used to execute certain embodiments corresponding to the above method.

[0198] In this embodiment, dielectric loss refers to the energy loss that occurs in the insulating material (such as the coil's insulating layer) due to polarization and other factors when an alternating electric field exists in the coil. Excessive dielectric loss can lead to energy waste in the form of heat, reducing the efficiency of wireless power transmission.

[0199] When the transmitting coil and receiving coil adopt a segmented capacitor compensation structure, the respective structures of the transmitting coil and receiving coil can be: distributed inductance. Distributed capacitance Distributed inductance Distributed capacitance Distributed inductance Distributed capacitance n is an integer ≥ 2, and its structure can be found in [reference needed]. Figure 3 .

[0200] Optionally, in some embodiments, distributed inductance , With distributed capacitance , Operating frequency Resonance at point, i.e. .

[0201] By employing a segmented capacitor compensation structure, dielectric losses in the coil during wireless power transmission can be effectively reduced, improving energy transmission efficiency and minimizing energy waste. Simultaneously, combined with control circuitry and related methods, intelligent control of wireless power harvesting can be achieved, ensuring efficient and stable operation of the device under various working conditions and providing reliable wireless charging services for drones.

[0202] This application also provides a wireless power harvesting control system for unmanned aerial vehicles (UAVs), including the aforementioned wireless power harvesting control device and a UAV. The UAV is equipped with a receiving coil for receiving wireless energy through resonant coupling with the transmitting coil in the wireless power harvesting control device. This wireless power harvesting control device can execute the methods provided in the above-described method embodiments, and its implementation principle and technical effects are similar; therefore, it will not be described in detail here. Figure 7 This is a schematic diagram of the structure of the UAV wireless power harvesting control system provided in this application, as shown below. Figure 7 As shown, a wireless power acquisition and control device (such as a relay drone wireless charging station) is installed on the power transmission lines between power poles along the drone inspection route. During the mission, the drone can autonomously land within the range of the device to replenish its power, realizing uninterrupted power replenishment during the line inspection process, thereby effectively expanding the inspection range of the drone and improving work efficiency.

[0203] Figure 8 Flowchart of the UAV wireless power harvesting and control method provided in this application Figure 2 ,like Figure 8 As shown, in this embodiment... Figures 1 to 7 Based on the embodiments, the wireless power harvesting control method for UAVs is described in detail, which includes:

[0204] S801, based on high-power energy harvesting technology with controllable excitation, constructs an equivalent circuit model of the energy harvesting iron core using experimental data, and realizes stable wireless energy harvesting on transmission lines through the four-quadrant characteristics of adjustable electronic load.

[0205] Based on the power obtained in S801, the circuit topology and parameters are designed, and a wireless power transmission module is designed to enable long-endurance wireless power harvesting for drones without the need for alignment.

[0206] Furthermore, based on the equivalent circuit model of the energy harvesting core constructed using S801, the energy harvesting characteristics are analyzed to establish energy harvesting control strategies under different operating conditions, in order to design and adjust the circuit topology and parameters in the UAV wireless energy harvesting control device: that is, based on the resistive-capacitive characteristics of the electronic load, control is performed under low current conditions in the transmission line. To achieve maximum power extraction; control when the transmission line current is large. This achieves constant power extraction. The subsequent BUCK circuit is connected to an adjustable electronic load to adjust the DC voltage obtained from the extraction to the input voltage required by the wireless power transfer module.

[0207] The wireless power transfer module can be a robust parity-time symmetric wireless power transfer system. This system requires a Class E power amplifier, resonator parameter design, and corresponding control strategy. By coordinating the designed Class E power amplifier parameters and resonator parameters with the corresponding control strategy, the wireless power transfer module can operate at a parity-time symmetric point with a specific coupling coefficient.

[0208] Based on the topology in S802, the coil design of S803 is optimized, and a low-loss capacitor segmentation compensation method is used to finally achieve efficient UAV power replenishment without alignment.

[0209] The low-loss segmented capacitor compensation method specifically involves distributing multiple capacitors in series within the resonant coil. A group of lumped capacitors (corresponding to distributed capacitors) is connected in series at intervals along the coil length. Each lumped capacitor and distributed inductor resonate in series at the operating frequency, thereby reducing the potential difference between coil turns, eliminating the large electric field between coil turns, and significantly reducing the dielectric loss of the resonant coil. Simultaneously, the large number of series-connected resonant capacitors introduces more solder joints to the resonator. Under high-frequency operating conditions, the increase in solder joints conversely increases the resonator loss of the system. Therefore, a COMSOL simulation model is established to analyze the loss of the distributed capacitor size and quantity, achieving the optimal capacitor segmented compensation design under optimal power consumption.

[0210] The UAV wireless power harvesting control method, device, and system provided in this application adopt a wireless power harvesting method to directly obtain energy from power transmission lines, eliminating the need for traditional UAV nests to provide power to the UAVs. This solves the problem of poor adaptability of traditional UAV nests to outdoor sites, simplifies the operation process, and saves manpower and resources. Furthermore, by combining multiple repeater coils with parity-time symmetrical wireless power transmission, the UAV can achieve efficient charging without alignment, enabling multi-hop UAVs to flexibly replenish power while conducting inspections, reducing UAV start-up and shutdown waiting time, and greatly improving the efficiency of UAV inspection work.

[0211] Based on the above embodiments, in some embodiments... Figure 9 Schematic diagram of the structure of the UAV wireless power harvesting control device provided in this application Figure 2 ,like Figure 9As shown, the UAV wireless power harvesting and control device may include an equivalent circuit of the power harvesting module (such as a power harvesting core, a full-bridge rectifier circuit, a signal detection circuit, a switching transistor drive circuit, etc.), a power harvesting module control strategy, a BUCK circuit and a BUCK circuit control strategy, a Class E power amplifier circuit, a parity-time symmetric wireless power transfer circuit, and a parity-time symmetric wireless power transfer circuit control strategy. The power harvesting section includes the equivalent circuit of the power harvesting module and the BUCK circuit; the control section includes the power harvesting module control strategy, the BUCK circuit control strategy, and the parity-time symmetric wireless power transfer circuit control strategy; and the wireless power transfer section includes the Class E power amplifier circuit and the parity-time symmetric wireless power transfer circuit.

[0212] In the simulation software, the distributed capacitance and inductance described in S803 are replaced by a lumped parameter model. The voltage and current information of the equivalent circuit of the power harvesting module are processed by the signal detection circuit and then sent to the DSP control circuit. After processing by the control algorithm, the switching transistors are turned on and off to achieve stable power harvesting. The power obtained from the equivalent circuit of the power harvesting module is processed by the BUCK circuit to obtain the stable 48V DC voltage required by the Class E power amplifier. The simulation results are as follows: Figure 10 As shown. The output of the BUCK circuit serves as the input of the Class E power amplifier. The voltage and current information of the parity-time symmetric wireless power transfer circuit is processed by the signal detection circuit and sent to the DSP control circuit to drive the Class E power amplifier to turn on and off, thereby ensuring that the output of the Class E power amplifier satisfies the parity-time symmetry condition, that is, the output is equivalent to a negative resistance equal to the load. Figure 11 and Figure 12 The figures show the simulated and measured voltage waveforms at the switching terminals of the Class E power amplifier in the symmetrical region of the wireless power transfer system. The figures demonstrate that the switching terminal voltage achieves good zero-derivative conduction in these two regions, reducing switching losses at high frequencies. Simultaneously, the energy replenishment effect under misalignment conditions of the UAV is simulated by controlling the change in the coupling coefficient of the coil. The simulation results and actual measurement results are shown below. Figure 13 and Figure 14 As shown, as long as the drone is within a certain range above the transmission coil, i.e. within the PT symmetrical area, wireless power replenishment with an efficiency greater than 80% can be achieved, proving that the drone wireless power harvesting control device and system provided in this application can realize drone power replenishment without alignment by harvesting power from the power transmission line.

[0213] Figure 15 A schematic diagram of the structure of the electronic device provided in this application. Figure 15 As shown, the electronic device 150 provided in this embodiment includes at least one processor 1501 and a memory 1502. Optionally, the device 150 further includes a communication component 1503. The processor 1501, memory 1502, and communication component 1503 are connected via a bus 1504.

[0214] In a specific implementation, at least one processor 1501 executes computer execution instructions stored in memory 1502, causing at least one processor 1501 to perform the above-described method.

[0215] The specific implementation process of processor 1501 can be found in the above method embodiments, and its implementation principle and technical effect are similar. It will not be repeated here.

[0216] In the above embodiments, it should be understood that the processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in this invention can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules within the processor.

[0217] The memory may include random access memory (RAM) and may also include non-volatile memory (NVM), such as at least one disk storage device.

[0218] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of illustration, the buses shown in the accompanying drawings are not limited to a single bus or a single type of bus.

[0219] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described method.

[0220] This application also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the above-described method.

[0221] The aforementioned readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The readable storage medium can be any available medium accessible to a general-purpose or special-purpose computer.

[0222] An exemplary readable storage medium is coupled to a processor, enabling the processor to read information from and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can reside in an Application Specific Integrated Circuit (ASIC). Alternatively, the processor and the readable storage medium can exist as discrete components in the device.

[0223] The division of units is merely a logical functional division; in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0224] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0225] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0226] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0227] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0228] It should be understood that the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and accompanying drawings of this application are intended to cover but not exclude inclusion. For example, a product or device that includes a series of components is not necessarily limited to those components that are explicitly listed, but may include other components that are not explicitly listed or that are inherent to such product or device.

[0229] As used in this application, the term "module" means any known or subsequently developed hardware, software, firmware, artificial intelligence, fuzzy logic, or combination of hardware and / or software code capable of performing the functions associated with that element.

[0230] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A wireless power harvesting control method for unmanned aerial vehicles (UAVs), characterized in that, The method is applied to a wireless power taking control device of a UAV, and comprises the following steps: obtaining a power transmission line current parameter; determining a target load mode based on the power transmission line current parameter, wherein the target load mode comprises a pure resistive load mode and a resistive-capacitive load mode; adjusting impedance characteristics of an adjustable electronic load in the wireless power taking control device of the UAV and excitation parameters of a power taking core in the wireless power taking control device of the UAV according to the target load mode; controlling the wireless power taking control device of the UAV to output a stable direct current voltage according to the adjusted excitation parameters and impedance characteristics.

2. The method of claim 1, wherein, The method further comprises the following steps: comparing the power transmission line current parameter with a preset current threshold value; if the power transmission line current parameter is less than the preset current threshold value, determining that the target load mode is the pure resistive load mode; if the power transmission line current parameter is greater than or equal to the preset current threshold value, determining that the target load mode is the resistive-capacitive load mode.

3. The method of claim 2, wherein, When the target load mode is the pure resistive load mode, the method further comprises the following steps: determining a target resistance value corresponding to maximum power taking power based on an equivalent circuit model of the power taking core; controlling the adjustable electronic load to work in a pure resistive mode and adjusting the resistance value of the adjustable electronic load to the target resistance value, so that the excitation parameters of the power taking core work in a maximum power taking state.

4. The method of claim 3, wherein, The method further comprises the following steps: obtaining actual excitation parameters of the power taking core through a no-load experiment on the power taking core; constructing an equivalent circuit model of the power taking core based on the actual excitation parameters; establishing a functional relationship between power taking power and load resistance based on the equivalent circuit model; deriving the functional relationship to obtain a load resistance value at which the power taking power takes a maximum value, and taking the load resistance value as the target resistance value.

5. The method of claim 2, wherein, When the target load mode is the resistive-capacitive load mode, the method further comprises the following steps: determining a target capacitive resistance value based on a constant power taking requirement; controlling the adjustable electronic load to work in a resistive-capacitive mode and adjusting the capacitive resistance value of the adjustable electronic load to the target capacitive resistance value, so that the excitation parameters of the power taking core work in a constant power taking state.

6. The method according to any one of claims 1-5, characterized in that, The wireless power taking control device of the UAV further comprises a wireless power transmission module. After the wireless power taking control device of the UAV outputs a stable direct current voltage according to the adjusted excitation parameters and impedance characteristics, the method further comprises the following steps: driving the wireless power transmission module to work based on the stable direct current voltage. determine a transmission efficiency parameter of the wireless power transmission module based on a coupling state between the transmitting coil and the receiving coil in the wireless power transmission module; dynamically adjust a circuit parameter of the wireless power transmission module according to the transmission efficiency parameter, so that the wireless power transmission module is in a time-reversal symmetric working state.

7. The method of claim 6, wherein, The dynamically adjusting a circuit parameter of the wireless power transmission module according to the transmission efficiency parameter, so that the wireless power transmission module is in a time-reversal symmetric working state, comprises: determining whether the wireless power transmission module is in a time-reversal symmetric working state based on the transmission efficiency parameter; if the wireless power transmission module is not in a time-reversal symmetric working state, dynamically adjusting a switching frequency of a class-E power amplifier in the wireless power transmission module and / or a resonance parameter of the transmitting coil and the receiving coil, so that the wireless power transmission module is in a time-reversal symmetric working state.

8. The method of claim 7, wherein, The transmission efficiency parameter is a coupling coefficient between the transmitting coil and the receiving coil. The determining whether the wireless power transmission module is in a time-reversal symmetric working state based on the transmission efficiency parameter, comprises: comparing the coupling coefficient with a critical coupling coefficient, the critical coupling coefficient being constructed based on an equivalent series resistance of a receiving side circuit, a load resistance, a natural working angular frequency of a resonator, and a receiving side resonator inductance in the wireless power transmission module; if the coupling coefficient is greater than or equal to the critical coupling coefficient, the wireless power transmission module is in a time-reversal symmetric working state; if the coupling coefficient is less than the critical coupling coefficient, the wireless power transmission module is not in a time-reversal symmetric working state.

9. The method of claim 6, wherein, The transmitting coil and the receiving coil in the wireless power transmission module adopt a low-loss capacitor segmented compensation structure, the capacitor segmented compensation structure being constructed by dispersively connecting a plurality of compensation capacitors in series in a coil conductor; The method further comprises: controlling the wireless power transmission module to work at a target resonance frequency based on the capacitor segmented compensation structure.

10. The method of claim 9, wherein, Before the controlling the wireless power transmission module to work at a target resonance frequency based on the capacitor segmented compensation structure, the method further comprises: obtaining a distributed parameter simulation model of the transmitting coil and / or the receiving coil in the wireless power transmission module, the distributed parameter simulation model being constructed based on an electromagnetic field simulation tool; based on the distributed parameter simulation model, performing optimization analysis on the number and position of the compensation capacitors in the capacitor segmented compensation structure, to determine a capacitor segmented compensation scheme that satisfies a preset loss condition at the target resonance frequency.

11. A wireless power control device for a drone, comprising: The power taking core, the adjustable electronic load, the signal detection circuit, the BUCK circuit, and the DSP control circuit are included. The power taking core is sleeved on the power transmission line, and is used for coupling to obtain alternating current power. An input end of the adjustable electronic load is connected with a secondary side winding of the power taking core, and an output end of the adjustable electronic load is connected with an input end of the BUCK circuit; the adjustable electronic load is used for adjusting equivalent impedance based on a control signal, and the BUCK circuit is used for outputting a stable direct current voltage; An input end of the signal detection circuit is connected with the secondary side winding and / or the BUCK circuit; the signal detection circuit is used for acquiring a power transmission line current parameter; An output end of the signal detection circuit is connected with an input end of the DSP control circuit, and an output end of the DSP control circuit is connected with a control end of the adjustable electronic load; wherein the DSP control circuit is used for executing the method in any one of claims 1-5.

12. The drone wireless power pickup control device of claim 11, wherein, The unmanned aerial vehicle wireless power taking control device further comprises a wireless power transmission module; An input end of the wireless power transmission module is connected with an output end of the BUCK circuit, and is used for receiving the stable direct current voltage and performing wireless charging for the unmanned aerial vehicle; The wireless power transmission module comprises a class-E power amplifier, a transmitting side resonant network and a receiving side resonant network, wherein the transmitting side resonant network comprises a transmitting coil, and the receiving side resonant network comprises a receiving coil; The DSP control circuit is further used for executing the method in any one of claims 6-8.

13. The drone wireless power pickup control device of claim 12, wherein, The transmitting coil and / or the receiving coil adopts a capacitive segmented compensation structure; wherein the capacitive segmented compensation structure is constructed by dispersively connecting a plurality of compensation capacitors in series in a coil conductor, and is used for reducing dielectric loss of the coil.

14. The drone wireless power pickup control device of claim 13, wherein, The DSP control circuit is further used for executing the method in claim 9 or 10.

15. A drone wireless power take-off control system, comprising: The unmanned aerial vehicle wireless power taking control device comprises the unmanned aerial vehicle wireless power taking control device in any one of claims 11-14, and an unmanned aerial vehicle; The unmanned aerial vehicle is provided with a receiving coil, and is used for receiving wireless energy through resonant coupling with a transmitting coil in the unmanned aerial vehicle wireless power taking control device.

Images