Solar unmanned aerial vehicle gliding power generation method, power generation device and solar unmanned aerial vehicle

Abstract

The invention discloses a solar unmanned aerial vehicle gliding power generation method and device and a solar unmanned aerial vehicle. The gliding power generation method comprises the following steps: controlling the solar unmanned aerial vehicle to glide without power; airflow in the gliding process drives propellers of the solar unmanned aerial vehicle to rotate, then a rotor of a motor is driven to rotate, and wind energy is converted into mechanical energy; after the rotor rotates, current is generated based on electromagnetic induction, and mechanical energy is converted into electric energy; the operation state of the motor is controlled, and electric energy is transmitted to the storage battery for storage. The airflows are utilized to drive the propellers of the solar unmanned aerial vehicle to rotate during unpowered gliding of the solar unmanned aerial vehicle, then the rotors of the motors are driven to rotate, wind energy is converted into mechanical energy, current is generated based on electromagnetic induction after the rotors rotate, and the mechanical energy is converted into electric energy; the solar unmanned aerial vehicle can supplement energy through wind power generation in the unpowered gliding process.

Description

Technical Field

[0001] The present invention belongs to the technical field of solar-powered unmanned aerial vehicles, and more specifically, relates to a solar-powered unmanned aerial vehicle gliding power generation method, a power generation device and a solar-powered unmanned aerial vehicle. Background Art

[0002] The energy density of solar drones is relatively low, mainly because they rely on solar panels to absorb light energy and convert it into electrical energy to drive flight. Compared with traditional fossil fuels, the energy carried and stored by solar drones is relatively low, which limits their flight altitude and endurance to a certain extent. It is also limited by energy density, especially the energy density of batteries. Solar drones convert light energy into electrical energy through the solar cells on board during the day. Part of the electrical energy is used for daytime flights, and part of the battery is stored in the battery for nighttime flights. Limited by the low energy density of batteries, solar drones need to lower their flight altitude at night, that is, the flight altitude is high during the day and low at night. From the daytime flight altitude to the nighttime flight altitude, the method of unpowered descent is mostly used, and the process lasts for several hours. Solar drones show the characteristics of high flight altitude during the day and low flight altitude at night. The purpose is to use the principle of aerodynamics to convert the flight altitude difference into gravitational potential energy and store it. When necessary, the gravitational potential energy can be released for unpowered gliding, thereby realizing energy conversion and utilization to a certain extent.

[0003] Wind power generation technology is a renewable energy technology that uses wind to drive wind turbines to convert wind energy into electrical energy. Based on the principle of aerodynamics, the technology captures wind energy through the rotating blades of wind turbines, which then drive the generator to generate electricity. Wind power generation systems usually include key components such as wind turbines, generators, power conversion devices, and control systems. Wind power generation technology has the advantages of wide resource distribution, clean and pollution-free, and relatively low operation and maintenance costs.

[0004] In order to overcome the energy shortcoming of solar drones, it is particularly important to use wind power generation as a supplementary energy source. By integrating a wind power generation device, the drone can capture stable airflow at high altitudes during gliding, convert it into electrical energy and store it in batteries, effectively supplementing energy.

[0005] The information disclosed in the background technology section of the present invention is only intended to deepen the understanding of the general background technology of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art already known to those skilled in the art. Summary of the invention

[0006] The purpose of the present invention is to propose a solar UAV gliding power generation method, a power generation device and a solar UAV, so as to alleviate the problem of insufficient energy during the night flight of the solar UAV, make full use of wind energy, and realize the energy replenishment of the solar UAV through wind power generation during the unpowered gliding process.

[0007] To achieve the above-mentioned purpose, the present invention proposes a solar-powered UAV gliding power generation method, a power generation device and a solar-powered UAV.

[0008] According to a first aspect of the present invention, a solar drone gliding power generation method is proposed, comprising:

[0009] Control solar-powered drones to glide without power;

[0010] The airflow during gliding drives the propeller of the solar drone to rotate, which in turn drives the rotor of the motor to rotate, thereby converting wind energy into mechanical energy;

[0011] After the rotor rotates, it generates electric current based on electromagnetic induction, converting the mechanical energy into electrical energy;

[0012] The operating state of the motor is controlled to transmit the electrical energy to the battery for storage.

[0013] Optionally, the motor comprises:

[0014] Brushless permanent magnet motor capable of four-quadrant operation.

[0015] Optionally, the four-quadrant operation includes:

[0016] Forward electric working state, forward feedback braking working state, reverse electric working state and reverse feedback braking working state.

[0017] Optionally, the motor is controlled to be in the forward feedback braking working state or the reverse feedback braking working state, and the current is transmitted to a battery for storage.

[0018] Optionally, the forward feedback braking working state or the reverse feedback braking working state includes:

[0019] By utilizing the inductance characteristics of the motor's own windings and adjusting the switches of the power tubes of each bridge arm of the three-phase inverter, a boost chopper circuit is formed. After the winding potential increases and the motor's back electromotive force acts, it is greater than the input voltage of the power supply end of the full-bridge rectifier circuit, and the current is transmitted to the battery through the full-bridge rectifier circuit.

[0020] Optionally, the power of the propeller converting wind energy is:

[0021] P=0.5ρV 3 SC p;

[0022] Where ρ is the air density at the propeller, V is the air velocity at the propeller, S is the propeller disc area, C p is the wind energy utilization coefficient of the propeller blades. If the propeller is a two-blade fixed pitch propeller, C p The value of is 0.2.

[0023] According to a second aspect of the present invention, a solar drone gliding power generation device is proposed, comprising:

[0024] Control module, used to control the solar-powered drone to glide without power;

[0025] A plurality of propellers and corresponding motors are used to drive the propellers to rotate based on the airflow during gliding, thereby driving the rotor of the motor to rotate, thereby converting wind energy into mechanical energy; after the rotor rotates, current is generated based on electromagnetic induction, thereby converting the mechanical energy into electrical energy;

[0026] A motor controller, used to control the running state of the motor and transmit the electric energy to a battery for storage;

[0027] A battery is used to store the electrical energy.

[0028] Optionally, the motor comprises:

[0029] Brushless permanent magnet motor capable of four-quadrant operation.

[0030] Optionally, the four-quadrant operation includes:

[0031] Forward electric working state, forward feedback braking working state, reverse electric working state and then reverse feedback braking working state.

[0032] According to a third aspect of the present invention, a solar-powered UAV is provided, wherein the solar-powered UAV comprises the solar-powered UAV gliding power generation device as described in any one of the second aspects.

[0033] The beneficial effects of the present invention are as follows: the present invention utilizes airflow to drive the propeller of the solar-powered UAV to rotate during the unpowered gliding of the solar-powered UAV, thereby driving the rotor of the motor to rotate, thereby converting wind energy into mechanical energy. After the rotor rotates, current is generated based on electromagnetic induction, thereby converting mechanical energy into electrical energy, thereby realizing energy replenishment of the solar-powered UAV through wind power generation during the unpowered gliding process.

[0034] The present invention has the following advantages:

[0035] 1. Solar drones glide for a long time without power during flight, and this process can be fully utilized to generate wind power without affecting flight;

[0036] 2. The propellers, motors, and motor controllers installed on the solar drone can be used as a set of wind power generation devices, without the need for additional equipment, to convert wind energy into electrical energy;

[0037] 3. When flying in a medium- and high-altitude environment, the wind speed is high and the wind direction is stable, so solar drones can use wind energy more effectively for energy replenishment;

[0038] 4. The application of wind power generation helps to further improve the endurance of solar-powered UAVs. Through reasonable scheduling and optimized energy management, solar and wind energy can be fully utilized in different flight phases and environments.

[0039] The system of the present invention has other characteristics and advantages, which will be apparent from the drawings incorporated herein and the following detailed description, or will be described in detail in the drawings incorporated herein and the following detailed description, which together serve to explain the specific principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, in which like reference numerals generally represent like components.

[0041] Figure 1 A flow chart showing the steps of a solar drone gliding power generation method according to the present invention.

[0042] Figure 2 A schematic diagram showing a cross section of a solar-powered UAV according to the present invention during multi-day flight.

[0043] Figure 3 A schematic diagram showing mechanical characteristic curves of the forward motoring working state, the forward feedback braking working state, the reverse motoring working state and the reverse feedback braking working state of the brushless permanent magnet motor according to the present invention is shown.

[0044] Figure 4 A schematic diagram showing the current flow direction when the propeller according to the present invention generates pulling force or thrust.

[0045] Figure 5 A schematic diagram showing the current flow direction when the propeller according to the present invention captures wind energy to feed back energy.

[0046] Figure 6 A schematic diagram showing the principle of wind energy absorption by a solar powered UAV propeller according to the present invention is shown.

[0047] Figure 7A schematic diagram of a solar-powered UAV gliding power generation device according to the second embodiment of the present invention is shown.

[0048] Figure 8 A schematic diagram of the distribution of propellers according to the second embodiment of the present invention is shown. DETAILED DESCRIPTION

[0049] The present invention will be described in more detail below with reference to the accompanying drawings. Although preferred embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0050] like Figure 1 As shown, a solar drone gliding power generation method according to the present invention comprises:

[0051] Control solar-powered drone to glide without power;

[0052] The airflow during gliding drives the propeller of the solar drone to rotate, which in turn drives the rotor of the motor to rotate, converting wind energy into mechanical energy.

[0053] When the rotor rotates, it generates current based on electromagnetic induction, converting mechanical energy into electrical energy;

[0054] Control the running status of the motor and transfer electrical energy to the battery for storage.

[0055] Specifically, Figure 2 As shown in the figure, the typical profile of a long-flight solar-powered UAV for multiple days is: after takeoff, it climbs to the maximum altitude, flies level at the maximum altitude, glides without power when the solar energy is insufficient, descends to the night flight altitude and then flies level; it climbs after sunrise on the second day and continues the flight process of the first day; after repeating this cycle for several days, it descends and lands. The time of unpowered gliding during the flight accounts for about 1 / 6 to 1 / 3 of the total flight time. Based on this feature, wind power generation can be carried out during the unpowered gliding process. Control the unpowered gliding of the solar-powered UAV, and use the propeller and motor of the solar-powered UAV as the blades and generator of the wind power generation device respectively. When the airflow passes through, the propeller starts to rotate, and the mechanical energy generated by the rotation of the propeller is transmitted to the motor through the motor shaft, realizing the conversion of wind energy into mechanical energy. The rotor inside the generator is organized into a spiral shape by the wire. When the rotor is acted upon by mechanical energy, the electrons in the wire begin to move, generating current, realizing the conversion of mechanical energy into electrical energy. The electrical energy generated by the motor is transmitted to the energy storage battery of the UAV for storage, or directly used for the power demand of the UAV, realizing the energy replenishment of the solar-powered UAV through wind power generation during the unpowered gliding process.

[0056] In one example, an electric machine includes:

[0057] Brushless permanent magnet motor capable of four-quadrant operation.

[0058] In one example, four-quadrant operation includes:

[0059] Forward electric working state, forward feedback braking working state, reverse electric working state and reverse feedback braking working state.

[0060] Specifically, Figure 3 The mechanical characteristic curves of the brushless permanent magnet motor in the forward electric working state, the forward feedback braking working state, the reverse electric working state and the reverse feedback braking working state are shown; when the propeller is required to generate pulling force or thrust, the motor runs in the forward electric or reverse electric working state, and its working current flows as follows Figure 4 As shown, the motor converts electrical energy into mechanical energy to drive the propeller to generate pulling force or thrust; when the propeller needs to capture wind energy for feedback energy, the motor operates in the forward feedback braking working state or the reverse feedback braking working state, and its working current flows as shown in the figure below. Figure 5 As shown, the motor converts the rotational mechanical energy generated by the propeller driven by wind energy into electrical energy and feeds it back into the battery.

[0061] In one example, the motor is controlled to be in a forward regenerative braking working state or a reverse regenerative braking working state, and current is transmitted to a battery for storage.

[0062] In one example, the forward regenerative braking working state or the reverse regenerative braking working state includes:

[0063] By utilizing the inductance characteristics of the motor's own windings and adjusting the switches of the power tubes in each bridge arm of the three-phase inverter, a boost chopper circuit is formed. The winding potential increases and reacts with the motor's back electromotive force to become greater than the input voltage at the power supply end of the full-bridge rectifier circuit, thereby transmitting the current to the battery through the full-bridge rectifier circuit.

[0064] Specifically, the brushless permanent magnet motor regenerative braking adopts the working principle of the boost chopper circuit, which utilizes the inductance characteristics of the motor's own windings and adjusts the switches of the power tubes of each bridge arm of the three-phase inverter to form a boost chopper circuit. The winding potential increases and after the action of the motor's back electromotive force, it is greater than the input voltage of the power supply end of the rectifier circuit, thereby realizing the energy feedback to the power supply end, i.e., the battery, through the full-bridge rectifier circuit.

[0065] In one example, the power of the propeller to convert wind energy is:

[0066] P=0.5ρV 3 SC p ;

[0067] Where ρ is the air density at the propeller, V is the air velocity at the propeller, S is the propeller disc area, C p is the wind energy utilization coefficient of the propeller blades. If the propeller is a two-blade fixed pitch propeller, C p The value of is 0.2.

[0068] Specifically, Figure 6 The figure shows the principle of wind energy absorption by solar drone propellers. The left side of the propeller disc is the incoming direction of the airflow, and its flow velocity is V1. After the airflow passes through the propeller disc, its velocity is V, and the airflow velocity on the right side of the propeller disc is V2. The cross-sectional area of ​​the airflow on the left side of the propeller disc in the incoming direction is S1, the propeller disc area is S, and the area of ​​the airflow at the downstream cross-section of the propeller disc is S2. Since the propeller disc has an obstructive effect on the airflow, the speeds before and after the propeller disc are significantly different, with V1 being higher than V2 and S1 being lower than S2. The formula for calculating the wind energy absorbed by the propeller is as follows: P = 0.5ρV 3 SC p ; Where: ρ is the air density at the propeller, V is the air velocity at the propeller, S is the propeller disc area, C p is the wind energy utilization coefficient of the propeller blades. If the propeller is a two-blade fixed pitch propeller, C p The value of is 0.2. Solar drones can optimize wind power generation efficiency by adjusting the angle of the propeller and the speed of the motor according to changes in wind speed and direction.

[0069] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments, but is not intended to be limiting of the present invention. It should be noted that the embodiments and features in the embodiments of the present invention may be combined with each other without conflict.

[0070] Embodiment 1

[0071] This embodiment provides a solar drone gliding power generation method, comprising:

[0072] Control solar-powered drones to glide without power;

[0073] The airflow during gliding drives the propeller of the solar drone to rotate, which in turn drives the rotor of the motor to rotate, converting wind energy into mechanical energy.

[0074] When the rotor rotates, it generates current based on electromagnetic induction, converting mechanical energy into electrical energy;

[0075] Control the running status of the motor and transfer electrical energy to the battery for storage.

[0076] The motor includes:

[0077] Brushless permanent magnet motor capable of four-quadrant operation.

[0078] Four-quadrant operation includes:

[0079] Forward electric working state, forward feedback braking working state, reverse electric working state and reverse feedback braking working state.

[0080] The motor is controlled to be in a forward feedback braking working state or a reverse feedback braking working state, and the current is transmitted to the battery for storage.

[0081] The forward feedback braking working state or the reverse feedback braking working state includes:

[0082] By utilizing the inductance characteristics of the motor's own windings and adjusting the switches of the power tubes in each bridge arm of the three-phase inverter, a boost chopper circuit is formed. The winding potential increases and reacts with the motor's back electromotive force to become greater than the input voltage at the power supply end of the full-bridge rectifier circuit, thereby transmitting the current to the battery through the full-bridge rectifier circuit.

[0083] The power of the propeller converting wind energy is:

[0084] P=0.5ρV 3 SC p ;

[0085] Where ρ is the air density at the propeller, V is the air velocity at the propeller, S is the propeller disc area, C p is the wind energy utilization coefficient of the propeller blades. If the propeller is a two-blade fixed pitch propeller, C p The value of is 0.2.

[0086] A solar-powered drone is equipped with 6 electric propellers, with a propeller diameter of 3m and a propeller disc area of ​​7m. 2 .

[0087] The air velocity of the solar drone at an altitude of 20km is about 30m / s, and the atmospheric density is 0.0889kg / m 3 , the power absorbed by a single blade is about 1680W. Considering the energy feeding efficiency of the motor is about 0.8, the electric power generated by the six power units is 8064W.

[0088] The air velocity of the solar drone at an altitude of 15km is about 20m / s, and the atmospheric density is 0.1948kg / m 3 , the power absorbed by a single blade is about 1091W. Considering the energy feeding efficiency of the motor is about 0.8, the electric power generated by the six power units is 5237W.

[0089] The air velocity of the solar drone at an altitude of 10km is about 15m / s, and the atmospheric density is 0.4135kg / m 3 , the power absorbed by a single blade is about 977W. Considering the energy feeding efficiency of the motor is about 0.8, the electric power generated by the six power units is 4690W.

[0090] It takes about 4 hours for a solar drone to glide from 20km to 10km. The power generation in this process is about 20kWh, which can effectively supplement energy.

[0091] Embodiment 2

[0092] like Figure 7 and Figure 8 As shown, this embodiment provides a solar drone gliding power generation device, comprising:

[0093] Motor 1, motor controller 2, propeller 3, battery 4 and power transmission cable 5;

[0094] Motor 1 is a brushless permanent magnet motor that can achieve four-quadrant operation;

[0095] The motor controller 2 matches the motor 1 and controls the switch, speed, direction, working mode, etc. of the motor 1;

[0096] The motor 1 and the propeller 3 are mechanically connected;

[0097] Propeller 3 is a large-diameter two-blade fixed-pitch propeller;

[0098] The battery 4 stores the electric energy converted by the motor 1;

[0099] The transmission cable 5 transmits the electric energy generated by the motor 1 to the battery 4;

[0100] The propeller 3, the motor 1, and the motor controller 2 are distributedly installed at the front end of the wing of the solar drone, and the number is designed and matched according to the overall parameters of the drone.

[0101] The four-quadrant operation of the motor 1 includes four working states: forward motoring, forward feedback braking, reverse motoring, and reverse feedback braking, which are specifically distinguished by the relative directions of the rotation speed and the electromagnetic torque.

[0102] The feedback braking of motor 1 adopts the working principle of the boost chopper circuit, which utilizes the inductance characteristics of the winding of motor 1 itself and adjusts the switches of the power tubes of each bridge arm of the three-phase inverter to form a boost chopper circuit. The winding potential increases and the motor back electromotive force acts to be greater than the input voltage of the power supply end of the rectifier circuit, thereby realizing energy feedback to the power supply end through the full-bridge rectifier circuit.

[0103] When the electric propeller 3 is required to generate pulling force or thrust, the motor 1 works in the forward motor (I) or reverse motor (III) state, and the motor 1 converts the absorbed electric energy into rotational mechanical energy and generates pulling force or thrust through the propeller 3. When the electric propeller 3 is required to capture wind energy for energy feedback, the motor 1 works in the forward feedback (II) or reverse feedback (IV) state, and the motor 1 converts the rotational mechanical energy generated by the propeller 3 driven by wind energy into electric energy and feeds it back to the battery 4.

[0104] Embodiment 3

[0105] This embodiment provides a solar-powered UAV, which includes the solar-powered UAV gliding power generation device described in the second embodiment.

[0106] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A solar drone gliding power generation method, characterized in that: include: Control solar-powered drones to glide without power; The airflow during gliding drives the propeller of the solar drone to rotate, which in turn drives the rotor of the motor to rotate, thereby converting wind energy into mechanical energy; After the rotor rotates, it generates electric current based on electromagnetic induction, converting the mechanical energy into electrical energy; The operating state of the motor is controlled to transmit the electrical energy to the battery for storage.

2. The solar drone gliding power generation method according to claim 1 is characterized in that: The motor comprises: Brushless permanent magnet motor capable of four-quadrant operation.

3. The solar drone gliding power generation method according to claim 2 is characterized in that: The four-quadrant operation includes: Forward electric working state, forward feedback braking working state, reverse electric working state and reverse feedback braking working state.

4. The solar drone gliding power generation method according to claim 3 is characterized in that: The motor is controlled to be in the forward feedback braking working state or the reverse feedback braking working state, and the current is transmitted to the battery for storage.

5. The solar drone gliding power generation method according to claim 4 is characterized in that: The forward feedback braking working state or the reverse feedback braking working state includes: By utilizing the inductance characteristics of the motor's own windings and adjusting the switches of the power tubes of each bridge arm of the three-phase inverter, a boost chopper circuit is formed. After the winding potential increases and the motor's back electromotive force acts, it is greater than the input voltage of the power supply end of the full-bridge rectifier circuit, and the current is transmitted to the battery through the full-bridge rectifier circuit.

6. The solar drone gliding power generation method according to claim 1, characterized in that: The power of the propeller converting wind energy is: P=0.5ρV 3 SC p ; Where ρ is the air density at the propeller, V is the air velocity at the propeller, S is the propeller disc area, C p is the wind energy utilization coefficient of the propeller blades. If the propeller is a two-blade fixed pitch propeller, C p The value of is 0.

2.

7. A solar powered UAV gliding power generation device, characterized in that: include: Control module, used to control the solar-powered drone to glide without power; A plurality of propellers and corresponding motors are used to drive the propellers to rotate based on the airflow during gliding, thereby driving the rotor of the motor to rotate, thereby converting wind energy into mechanical energy; after the rotor rotates, current is generated based on electromagnetic induction, thereby converting the mechanical energy into electrical energy; A motor controller, used to control the running state of the motor and transmit the electric energy to a battery for storage; A battery is used to store the electrical energy.

8. The solar powered UAV gliding power generation device according to claim 7, characterized in that: The motor comprises: Brushless permanent magnet motor capable of four-quadrant operation.

9. The solar powered UAV gliding power generation device according to claim 8, characterized in that: The four-quadrant operation includes: Forward electric working state, forward feedback braking working state, reverse electric working state and then reverse feedback braking working state.

10. A solar-powered drone, characterized in that: The solar-powered UAV comprises the solar-powered UAV gliding power generation device as described in any one of claims 7-9.

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