Hydrogen fuel cell energy management system and method for hydrogen-powered UAVs

Abstract

The present invention relates to the field of energy management, and specifically to a hydrogen fuel cell energy management system and method for hydrogen-powered drones, comprising: a fuel cell module, a catalytic control module, a drone attitude module, a reaction power module, and a hydrogen-oxygen circulation module. The fuel cell module is used to read the air pressure of each cabin, the catalytic control module is used to control the reaction activity of the fuel cell, the drone attitude module is used to obtain the flight parameters of the drone and calculate the power required for the next time sequence, the reaction power module is used to determine the output power of the fuel cell and adjust the amount of catalyst involved, and the hydrogen-oxygen circulation module is used to pressurize the oxygen cabin and adjust the output power of the fuel cell. The present invention can optimize the electrochemical reaction rate, improve the dynamic response capability of the fuel cell, enable it to quickly adapt to load changes, and at the same time improve the startup performance of the fuel cell, extend the service life of the fuel cell, and enhance the battery efficiency and safety performance.

Description

Technical Field

[0001] The present invention relates to the field of energy management, and in particular to a hydrogen fuel cell energy management system and method for hydrogen-powered UAVs. Background Art

[0002] A hydrogen fuel cell is a device that converts the chemical energy of hydrogen directly into electrical energy. Hydrogen is supplied to the anode of the fuel cell as fuel, and oxygen is supplied to the cathode as a combustion aid. The movement of protons in the electrolyte membrane generates an electric current, which powers the device. A typical hydrogen fuel cell consists of a hydrogen chamber, an oxygen chamber, a fuel reactor, and a water vapor circulation chamber. Hydrogen fuel cells primarily produce water, making them lighter and more environmentally friendly than traditional lithium batteries. Therefore, drones powered by hydrogen fuel cells have longer flight times and more stable flight, making them widely used in logistics, inspection, and other fields.

[0003] However, hydrogen fuel cells also have some issues, the most significant of which stems from reaction rate instability. The output power of hydrogen fuel cells is significantly affected by the pressure, temperature, and catalytic strength of the hydrogen and oxygen gases, which can lead to unstable output power under complex operating conditions. Commonly used power regulation technologies rely on external power control, adjusting actual power through circuit changes. This approach can easily waste energy and increase the risk of circuit failure.

[0004] In addition, the flight process of a drone is relatively complicated. The power required for level flight, climbing, and landing is different. In addition, during the operation of a hydrogen fuel cell, hydrogen is continuously consumed, and water vapor as a combustion product escapes into the environment, causing the weight of the battery itself to change, increasing the difficulty of battery energy management. Summary of the Invention

[0005] The purpose of the present invention is to provide a hydrogen fuel cell energy management system and method for a hydrogen-powered UAV to solve the problems raised in the above-mentioned background technology.

[0006] In a first aspect, the present application provides a hydrogen fuel cell energy management system for hydrogen-powered drones, which adopts the following technical solution: the system includes: a fuel cell module, a catalytic control module, a drone attitude module, a reaction power module, and a hydrogen-oxygen circulation module;

[0007] The fuel cell module consists of a hydrogen tank, an oxygen tank, a fuel reactor, and a water vapor circulation tank. The hydrogen tank is used to store hydrogen fuel, the oxygen tank is used to absorb oxygen from the outside, and the water vapor circulation tank is used to collect byproducts obtained after battery combustion. A pressure valve is used to connect the hydrogen tank, oxygen tank, and water vapor circulation tank to read the air pressure in each chamber in real time. At the same time, the fuel cell chips are connected in series, and a DC-DC converter is used to connect the battery output terminal to the drone engine.

[0008] The catalytic control module is used to add a catalyst layer between the cathode and anode diffusion layers of the hydrogen fuel cell, and control the reaction activity of the fuel cell by adjusting the amount of catalyst involved. When the fuel cell is operating, the thermodynamic electromotive force and polarization overpotential of a single cell are calculated based on the gas pressure of each compartment and the reaction activity, and a steady-state output model of the fuel cell is established. Historical data is input into the steady-state output model, and the energy conversion ratio of the cell is output. The correlation function between the output power of the fuel cell and the amount of catalyst involved is obtained by fitting;

[0009] The UAV attitude module is used to obtain the flight parameters of the UAV, determine the thrust, speed and climbing altitude of the UAV, and receive control signals from the UAV control terminal. The dynamic mass of the energy system is calculated based on the initial weight of the fuel cell, hydrogen storage density, hydrogen tank pressure and reaction energy density. Based on the total mass and flight parameters of the UAV, the power required for the UAV flight and the power required for the next time sequence action are calculated. The total mass is the sum of the dynamic mass of the fuel cell and the mass of the UAV body.

[0010] The reaction power module is used to convert the output power into the engine speed of the drone through a DC-DC converter. Based on the efficiency of the speed governor, motor and propeller, the output power of the fuel cell is determined so that the total power required by the drone in the next time sequence is the same as the output power of the engine. The correlation function between the output power of the fuel cell and the amount of catalyst participation is substituted into the function to obtain the amount of catalyst participation, and the volume of the catalyst layer in the reactor is adjusted according to the amount of catalyst participation.

[0011] The hydrogen-oxygen circulation module is used to calculate the oxygen partial pressure when the speed increase rate is the highest when the battery power is insufficient, pressurize the gas in the water vapor circulation chamber and input it into the oxygen chamber, pressurize the oxygen chamber by mechanical compression or auxiliary energy compression, and adjust the oxygen pressure to maximize the output power of the fuel cell.

[0012] Furthermore, the fuel cell module includes: a pressurized cabin unit and a fuel stack unit;

[0013] The pressurized cabin unit is used to read the pressure of the hydrogen cabin, oxygen cabin and water vapor circulation cabin, and connect the oxygen cabin and water vapor circulation cabin to adjust the oxygen supply pressure;

[0014] The fuel stack unit is used to provide a reaction space for the fuel cell and simultaneously connect the battery cells in series to obtain a higher output voltage.

[0015] Furthermore, the catalytic control module includes: a catalyst layer unit, a polarization output unit and a power feedback unit;

[0016] The catalyst layer unit is used to accelerate the reaction rate of the fuel cell using platinum as a catalyst, and the amount of catalyst involved is controlled by controlling the insertion ratio of the platinum layer;

[0017] The polarization output unit is used to calculate the thermodynamic electromotive force, activation polarization overpotential, ohmic polarization overpotential and concentration polarization overpotential of a single battery;

[0018] The power feedback unit is used to establish a steady-state output model of the fuel cell and calculate a correlation function between the output power of the fuel cell and the amount of catalyst involved.

[0019] Furthermore, the UAV attitude module includes: an attitude sensing unit, a dynamic mass unit and a timing requirement unit;

[0020] The attitude sensing unit is composed of a gyroscope, an airspeed meter and an altimeter in the UAV, and is used to obtain the flight parameters of the UAV;

[0021] The dynamic mass unit is used to calculate the real-time mass of the hydrogen fuel cell and the real-time flight power of the UAV;

[0022] The timing demand unit is used to receive the flight instructions of the controller to the UAV and determine the dynamic power demand of the UAV at the next moment.

[0023] Furthermore, the reaction power module includes: a reaction adjustment unit and a speed matching unit;

[0024] The reaction adjustment unit is used to adjust the amount of catalyst involved according to the total power demand of the next time sequence of the UAV;

[0025] The speed matching unit is used to fit the relationship between the UAV engine speed and the battery output power, and determine the battery power requirement of the UAV at the next moment.

[0026] Furthermore, the hydrogen and oxygen circulation module includes: a partial pressure measurement unit and a cabin pressurization unit;

[0027] The partial pressure measuring unit is used to calculate the oxygen partial pressure when the engine speed increases at the maximum speed;

[0028] The cabin pressurizing unit is used to compress the oxygen cabin using water vapor, or to electrolyze water vapor using auxiliary energy to increase the air pressure in the oxygen cabin.

[0029] In a second aspect, the present application provides a hydrogen fuel cell energy management method for a hydrogen-powered UAV, which adopts the following technical solution: the method comprises the following steps:

[0030] Step S1. Use pressure valves to connect the hydrogen chamber, oxygen chamber, and water vapor circulation chamber, read the air pressure in each chamber in real time, and simultaneously add a catalyst layer between the cathode and anode diffusion layers of the hydrogen fuel cell. By controlling the volume of the catalyst layer entering the fuel cell stack, the reaction activity of the fuel cell is controlled;

[0031] Step S2. When the fuel cell is operating, the thermodynamic electromotive force and polarization overpotential of a single cell are calculated based on the gas pressure and reaction activity of each compartment. A steady-state output model of the fuel cell is established, and the functional relationship between the catalyst loading and the cell output power is derived using the catalytic test results.

[0032] Step S3. Calculate the dynamic mass of the energy system based on the fuel cell's initial weight, hydrogen storage density, hydrogen tank pressure, and reaction energy density. Obtain the drone's flight parameters in real time and calculate the required flight power of the drone based on the total mass and flight parameters. The total mass is the sum of the dynamic mass of the fuel cell and the drone's body mass.

[0033] Step S4. Receive flight instructions from the controller for the UAV, calculate the power required for the UAV to execute the flight instructions in the next sequence, add the power required to the flight power, and calculate the total power required for the UAV in the next sequence. Substitute the total power required into the functional relationship between the catalyst dosage and the battery output power to obtain the catalyst dosage, thereby adjusting the fuel cell reactor.

[0034] Step S5. Connect the fuel cell output terminal to the UAV engine via a DC-DC converter. When the battery power is insufficient based on the obtained catalyst participation amount, calculate the oxygen partial pressure in the fuel cell when the engine speed increases at the maximum speed, and use water vapor to compress the oxygen chamber to increase the air pressure in the oxygen chamber.

[0035] Furthermore, step S1 includes:

[0036] Step S11. Set up sealed compartments within the fuel cell. Fill the compartment leading to the anode flow field plate with hydrogen fuel, and the compartment leading to the cathode flow field plate with oxygen or air. The compartment connected to the current collecting plate is used to collect water vapor products. All compartments are equipped with pressure valves that connect each compartment to the reactor and read the gas pressure within the compartments.

[0037] Step S12. Add catalyst layers on both sides of the proton exchange membrane in the hydrogen fuel cell reactor. The catalysts used in the catalyst layers include carbon-supported platinum catalysts and Pt-M / C alloy catalysts. The catalyst layers are scalable. By adjusting the volume of the catalyst layer entering the fuel cell stack, the amount of catalyst involved is controlled, thereby controlling the reaction activity of the fuel cell.

[0038] Furthermore, step S2 includes:

[0039] Step S21. When the fuel cell is operating, the thermodynamic electromotive force and polarization overpotential of a single cell are calculated using the steady-state output model in step S22 according to the indoor test results of the fuel cell. The polarization overpotential includes activation polarization overpotential, ohmic polarization overpotential, and concentration polarization overpotential. The output voltage of the fuel cell is calculated based on the thermodynamic electromotive force and polarization overpotential:

[0040] ;

[0041] Where V represents the output voltage of the fuel cell, E N represents the thermodynamic electromotive force, Vact, Vohm and Vcon represent the activation polarization overpotential, ohmic polarization overpotential and concentration polarization overpotential respectively;

[0042] Step S22: Establish a steady-state output model of the fuel cell, so that the steady-state output model satisfies: ;

[0043] Where V0 represents the test voltage value of the fuel cell, T is the current temperature, T0 is the test temperature, s0 is the standard molar entropy change, F is the Faraday constant, R is the gas constant, P H2 、P O2 and P H2O Represent the pressures of hydrogen, oxygen and water vapor respectively, i represents the current density, i0 represents the critical current density of the exchange membrane, Rc and Rm represent the equivalent impedance of the electrode and the exchange membrane respectively, i max represents the maximum value of current density;

[0044] Step S23. Adding different amounts of catalyst to participate in the reaction, measuring the current density, and fitting the functional relationship between the amount of catalyst and the current density so that the current density satisfies: i = F(a), where a represents the amount of catalyst, and F(a) represents the effect of the catalyst on the current density;

[0045] The current density is multiplied by the output voltage to obtain the functional relationship P(a) between the amount of catalyst involved and the battery output power, which satisfies P(a)=i·e·V, where e is the electron charge.

[0046] Furthermore, step S3 includes:

[0047] Step S31. The total mass of the UAV is obtained by adding the dynamic mass of the fuel cell and the mass of the UAV body to calculate the dynamic mass of the hydrogen fuel cell:

[0048] ;

[0049] Where M represents the dynamic mass of the battery, Ef represents the fixed mass of the battery system, pH represents the hydrogen density at the current pressure, DH represents the fuel stack reaction density of hydrogen, σ1 represents the maximum hydrogen release rate of the hydrogen cabin, and σ2 represents the hydrogen conversion efficiency;

[0050] Step S32: Obtain the flight parameters of the UAV, including the thrust, speed, and altitude of the UAV, and determine the power required for the UAV's flight:

[0051] ;

[0052] Among them, PW is the flight power required by the UAV, M0 is the mass of the UAV body, Cd and Cu represent the drag coefficient and lift coefficient respectively, g is the acceleration of gravity, p is the air density, S is the equivalent area of the wing, μ is the battery efficiency, and Pd is the additional power demand.

[0053] Furthermore, step S4 includes:

[0054] Step S41: Obtain the flight command from the controller. Based on the changes in the drone's speed and altitude caused by the flight command, calculate the power required for the drone to execute the flight command in the next sequence. Add this to the flight power required for the current sequence to obtain the total power required for the next sequence.

[0055] Step S42. Let P(a) = the total required power for the next time sequence, solve for the theoretical value of the catalyst participation amount a, and adjust the volume of the current catalyst layer entering the fuel cell stack so that the catalyst participation amount is equal to the theoretical value.

[0056] Furthermore, step S5 includes:

[0057] Step S51: The output power is converted into the engine speed of the UAV through a DC-DC converter. When the theoretical value of the catalyst participation exceeds the adjustment range of the catalyst layer, it is determined that the battery power is insufficient;

[0058] Step S52. Calculate the adjustment amount of the oxygen partial pressure to increase the thermodynamic electromotive force of the fuel cell so that the theoretical value of the catalyst participation amount falls back into the adjustment range of the catalyst layer, use water vapor to compress the oxygen chamber, or use auxiliary energy to electrolyze water vapor to increase the air pressure in the oxygen chamber.

[0059] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0060] 1. The present invention utilizes pressure valves to connect the hydrogen, oxygen, and water vapor circulation chambers to obtain the partial pressures of each gas in the fuel cell in real time. A catalyst layer is added between the cathode and anode diffusion layers of the cell. By adjusting the amount of catalyst involved to control the reaction activity, the electrochemical reaction rate can be optimized, allowing the fuel cell to operate in an optimal working state, thereby improving energy conversion efficiency, reducing energy waste, and extending the service life of the fuel cell.

[0061] 2. The present invention calculates the operating power of the UAV based on its thrust, speed, and climbing altitude, calculates the dynamic quality of the energy system from the hydrogen storage density and reaction energy density, adjusts the output power of the battery to match the actual output power with the required power, improves the dynamic response capability of the fuel cell, enables it to quickly adapt to load changes, and maintains stable battery output performance under different flight conditions.

[0062] 3. The present invention converts the output power into the engine speed of the UAV through a DC converter, calculates the oxygen partial pressure when the speed increases at the maximum rate, pressurizes the gas in the water vapor circulation chamber and inputs it into the oxygen chamber, so that the output power of the battery reaches the maximum value, improves the starting performance of the fuel cell, realizes the secondary utilization of water vapor, and can realize hydrogen circulation in combination with auxiliary energy, significantly improving the performance, efficiency and safety of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0064] Figure 1 This is a schematic structural diagram of a hydrogen fuel cell energy management system for a hydrogen-powered UAV according to the present invention;

[0065] Figure 2 It is a schematic diagram of the steps of the hydrogen fuel cell energy management method for hydrogen-powered UAVs of the present invention. DETAILED DESCRIPTION

[0066] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0067] See also Figure 1 , the present invention provides a technical solution: a hydrogen fuel cell energy management system for hydrogen-powered UAVs, comprising: a fuel cell module, a catalytic control module, a UAV attitude module, a reaction power module, and a hydrogen-oxygen cycle module;

[0068] The fuel cell module consists of a hydrogen tank, an oxygen tank, a fuel reactor, and a water vapor circulation tank. The hydrogen tank is used to store hydrogen fuel, the oxygen tank is used to absorb oxygen from the outside, and the water vapor circulation tank is used to collect byproducts obtained after battery combustion. A pressure valve is used to connect the hydrogen tank, oxygen tank, and water vapor circulation tank to read the air pressure in each chamber in real time. At the same time, the fuel cell chips are connected in series, and a DC-DC converter is used to connect the fuel cell output end to the drone engine.

[0069] The fuel cell module includes: a pressurized chamber unit and a fuel stack unit;

[0070] The pressurized cabin unit is used to read the pressure of the hydrogen cabin, oxygen cabin and water vapor circulation cabin, and connect the oxygen cabin and water vapor circulation cabin to adjust the oxygen supply pressure;

[0071] The fuel stack unit is used to provide a reaction space for the fuel cell and simultaneously connect the battery cells in series to obtain a higher output voltage.

[0072] The catalytic control module is used to add a catalyst layer between the cathode and anode diffusion layers of the hydrogen fuel cell, and control the reaction activity of the fuel cell by adjusting the amount of catalyst involved. When the fuel cell is operating, the thermodynamic electromotive force and polarization overpotential of a single cell are calculated based on the gas pressure of each compartment and the reaction activity, and a steady-state output model of the fuel cell is established. Historical data is input into the steady-state output model, and the energy conversion ratio of the cell is output. The correlation function between the output power of the fuel cell and the amount of catalyst involved is obtained by fitting;

[0073] The catalytic control module includes: a catalyst layer unit, a polarization output unit and a power feedback unit;

[0074] The catalyst layer unit is used to accelerate the reaction rate of the fuel cell using platinum as a catalyst, and the amount of catalyst involved is controlled by controlling the insertion ratio of the platinum layer;

[0075] The polarization output unit is used to calculate the thermodynamic electromotive force, activation polarization overpotential, ohmic polarization overpotential and concentration polarization overpotential of a single battery;

[0076] The power feedback unit is used to establish a steady-state output model of the fuel cell and calculate a correlation function between the output power of the fuel cell and the amount of catalyst involved.

[0077] The UAV attitude module is used to obtain the flight parameters of the UAV, determine the thrust, speed and climbing altitude of the UAV, and receive control signals from the UAV control terminal. The dynamic mass of the energy system is calculated based on the initial weight of the fuel cell, hydrogen storage density, hydrogen tank pressure and reaction energy density. Based on the total mass and flight parameters of the UAV, the power required for the UAV flight and the power required for the next time sequence action are calculated. The total mass is the sum of the dynamic mass of the fuel cell and the mass of the UAV body.

[0078] The UAV attitude module includes: an attitude sensing unit, a dynamic mass unit and a timing requirement unit;

[0079] The attitude sensing unit is composed of a gyroscope, an airspeed meter and an altimeter in the UAV, and is used to obtain the flight parameters of the UAV;

[0080] The dynamic mass unit is used to calculate the real-time mass of the fuel cell and the real-time flight power of the UAV;

[0081] The timing demand unit is used to receive the flight instructions of the controller to the UAV and determine the dynamic power demand of the UAV at the next moment.

[0082] The reaction power module is used to convert the output power into the engine speed of the drone through a DC-DC converter. Based on the efficiency of the speed governor, motor and propeller, the output power of the fuel cell is determined so that the total power required by the drone in the next time sequence is the same as the output power of the engine. The correlation function between the output power of the fuel cell and the amount of catalyst participation is substituted into the function to obtain the amount of catalyst participation, and the volume of the catalyst layer in the reactor is adjusted according to the amount of catalyst participation.

[0083] The reaction power module includes: a reaction adjustment unit and a speed matching unit;

[0084] The reaction adjustment unit is used to adjust the amount of catalyst involved according to the total power demand of the next time sequence of the UAV;

[0085] The speed matching unit is used to fit the relationship between the UAV engine speed and the battery output power, and determine the battery power requirement of the UAV at the next moment.

[0086] The hydrogen-oxygen circulation module is used to calculate the oxygen partial pressure when the speed increase rate is the highest when the battery power is insufficient, pressurize the gas in the water vapor circulation chamber and input it into the oxygen chamber, pressurize the oxygen chamber by mechanical compression or auxiliary energy compression, and adjust the oxygen pressure to maximize the output power of the battery.

[0087] The hydrogen and oxygen circulation module includes: a partial pressure measurement unit and a cabin pressurization unit;

[0088] The partial pressure measuring unit is used to calculate the oxygen partial pressure when the engine speed increases at the maximum speed;

[0089] The cabin pressurizing unit is used to compress the oxygen cabin using water vapor, or to electrolyze water vapor using auxiliary energy to increase the air pressure in the oxygen cabin.

[0090] like Figure 2 As shown, the hydrogen fuel cell energy management method for a hydrogen-powered UAV includes the following steps:

[0091] Step S1. Use pressure valves to connect the hydrogen chamber, oxygen chamber, and water vapor circulation chamber, read the air pressure in each chamber in real time, and simultaneously add a catalyst layer between the cathode and anode diffusion layers of the hydrogen fuel cell. By controlling the volume of the catalyst layer entering the fuel cell stack, the reaction activity of the fuel cell is controlled;

[0092] Step S1 includes:

[0093] Step S11. Set up sealed compartments within the fuel cell. Fill the compartment leading to the anode flow field plate with hydrogen fuel, and the compartment leading to the cathode flow field plate with oxygen or air. Set up a chamber connected to the current collecting plate to collect water vapor products. All compartments are equipped with pressure valves, connecting each compartment to the reactor through the pressure valves, and reading the gas pressure within the compartments.

[0094] Step S12. Add catalyst layers on both sides of the proton exchange membrane in the hydrogen fuel cell reactor. The catalysts used in the catalyst layers include carbon-supported platinum catalysts and Pt-M / C alloy catalysts. The catalyst layers are scalable. By adjusting the volume of the catalyst layer entering the fuel cell stack, the amount of catalyst involved is controlled, thereby controlling the reaction activity of the fuel cell.

[0095] Step S2. When the fuel cell is operating, the thermodynamic electromotive force and polarization overpotential of a single cell are calculated based on the gas pressure and reaction activity of each compartment. A steady-state output model of the fuel cell is established, and the functional relationship between the catalyst loading and the cell output power is derived using the catalytic test results.

[0096] Step S2 includes:

[0097] Step S21. When the fuel cell is operating, the thermodynamic electromotive force and polarization overpotential of a single cell are calculated using the steady-state output model in step S22 according to the indoor test results of the fuel cell. The polarization overpotential includes activation polarization overpotential, ohmic polarization overpotential, and concentration polarization overpotential. The output voltage of the fuel cell is calculated based on the thermodynamic electromotive force and polarization overpotential:

[0098] ;

[0099] Where V represents the output voltage of the fuel cell, E Nrepresents the thermodynamic electromotive force, Vact, Vohm and Vcon represent the activation polarization overpotential, ohmic polarization overpotential and concentration polarization overpotential respectively;

[0100] Step S22: Establish a steady-state output model of the fuel cell, so that the steady-state output model satisfies:

[0101] ;

[0102] Where V0 represents the test voltage value of the fuel cell, T is the current temperature, T0 is the test temperature, s0 is the standard molar entropy change, F is the Faraday constant, R is the gas constant, P H2 、P O2 and P H2O Represent the pressures of hydrogen, oxygen and water vapor respectively, i represents the current density, i0 represents the critical current density of the exchange membrane, Rc and Rm represent the equivalent impedance of the electrode and the exchange membrane respectively, i max represents the maximum value of current density;

[0103] Step S23. Adding different amounts of catalyst to participate in the reaction, measuring the current density, and fitting the functional relationship between the amount of catalyst and the current density so that the current density satisfies: i = F(a), where a represents the amount of catalyst, and F(a) represents the effect of the catalyst on the current density;

[0104] The current density is multiplied by the output voltage to obtain the functional relationship P(a) between the amount of catalyst involved and the battery output power, which satisfies P(a)=i·e·V, where e is the electron charge.

[0105] Step S3. Calculate the dynamic mass of the energy system based on the fuel cell's initial weight, hydrogen storage density, hydrogen tank pressure, and reaction energy density. Obtain the drone's flight parameters in real time and calculate the required flight power of the drone based on the total mass and flight parameters. The total mass is the sum of the dynamic mass of the fuel cell and the drone's body mass.

[0106] Step S3 includes:

[0107] Step S31. The total mass of the UAV is obtained by adding the dynamic mass of the fuel cell and the mass of the UAV body to calculate the dynamic mass of the hydrogen fuel cell:

[0108] ;

[0109] Where M represents the dynamic mass of the fuel cell, Ef represents the fixed mass of the battery system, pH represents the hydrogen density at the current pressure, DH represents the fuel stack reaction density of hydrogen, σ1 represents the maximum hydrogen release rate of the hydrogen compartment, and σ2 represents the hydrogen conversion efficiency;

[0110] Step S32: Obtain the flight parameters of the UAV, including the thrust, speed, and altitude of the UAV, and determine the power required for the UAV's flight:

[0111] ;

[0112] Among them, PW is the flight power required by the UAV, M0 is the mass of the UAV body, Cd and Cu represent the drag coefficient and lift coefficient respectively, g is the acceleration of gravity, p is the air density, S is the equivalent area of the wing, μ is the battery efficiency, and Pd is the additional power demand.

[0113] Step S4. Receive flight instructions from the controller for the UAV, calculate the power required for the UAV to execute the flight instructions in the next sequence, add the power required to the flight power, and calculate the total power required for the UAV in the next sequence. Substitute the total power required into the functional relationship between the catalyst dosage and the battery output power to obtain the catalyst dosage, thereby adjusting the fuel cell reactor.

[0114] Step S4 includes:

[0115] Step S41: Obtain the flight command from the controller. Based on the changes in the drone's speed and altitude caused by the flight command, calculate the power required for the drone to execute the flight command in the next sequence. Add this to the flight power required for the current sequence to obtain the total power required for the next sequence.

[0116] Step S42. Let P(a) = the total required power for the next time sequence, solve for the theoretical value of the catalyst participation amount a, and adjust the volume of the current catalyst layer entering the fuel cell stack so that the catalyst participation amount is equal to the theoretical value.

[0117] Step S5. Connect the fuel cell output terminal to the UAV engine via a DC-DC converter. When the battery power is insufficient based on the obtained catalyst participation amount, calculate the oxygen partial pressure in the fuel cell when the engine speed increases at the maximum speed, and use water vapor to compress the oxygen chamber to increase the air pressure in the oxygen chamber.

[0118] Step S5 includes:

[0119] Step S51: The output power is converted into the engine speed of the UAV through a DC-DC converter. When the theoretical value of the catalyst participation exceeds the adjustment range of the catalyst layer, it is determined that the battery power is insufficient;

[0120] Step S52. Calculate the adjustment amount of the oxygen partial pressure to increase the thermodynamic electromotive force of the fuel cell so that the theoretical value of the catalyst participation amount falls back into the adjustment range of the catalyst layer, use water vapor to compress the oxygen chamber, or use auxiliary energy to electrolyze water vapor to increase the air pressure in the oxygen chamber.

[0121] Example: During the flight of a drone, the dynamic mass of the fuel cell is 500g, the mass of the drone is 1500g, the flight power required is 200W, and at the next moment, a command to rise 2m is received. The efficiency is 75%, so the total required power is 500W, and the amount of catalyst involved is 0.1m 3 , the catalyst layer is adjusted so that the volume of the catalyst layer entering the fuel pile reaches 0.1m 3 .

[0122] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0123] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A hydrogen fuel cell energy management method for a hydrogen-powered UAV, characterized in that: The method comprises the following steps: Step S1. Use pressure valves to connect the hydrogen chamber, oxygen chamber, and water vapor circulation chamber to read the air pressure in each chamber in real time. Simultaneously, add a catalyst layer between the cathode and anode diffusion layers of the fuel cell. By controlling the volume of the catalyst layer entering the fuel cell stack, the reaction activity of the fuel cell is controlled. Step S2. When the fuel cell is operating, the thermodynamic electromotive force and polarization overpotential of a single cell are calculated based on the gas pressure and reaction activity of each compartment. A steady-state output model of the fuel cell is established. Based on the steady-state output model and catalytic test results, a functional relationship between the catalyst loading and the cell output power is derived. Step S3. Calculate the dynamic mass of the energy system based on the fuel cell's initial weight, hydrogen storage density, hydrogen tank pressure, and reaction energy density. Obtain the drone's flight parameters in real time and calculate the required flight power of the drone based on the total mass and flight parameters. The total mass is the sum of the dynamic mass of the fuel cell and the drone's body mass. Step S4. Receive flight instructions from the controller for the UAV, calculate the power required for the UAV to execute the flight instructions in the next sequence, add the power required to the flight power, and calculate the total power required for the UAV in the next sequence. Substitute the total power required into the functional relationship between the catalyst dosage and the battery output power to obtain the catalyst dosage, thereby adjusting the fuel cell reactor. Step S5. Connecting the fuel cell output to the drone engine via a DC-DC converter. If insufficient battery power is determined based on the catalyst concentration, the oxygen partial pressure within the fuel cell is calculated when the engine speed increases at the highest rate. The oxygen chamber is then compressed using water vapor to increase the pressure within the chamber. Step S2 includes: Step S21. When the fuel cell is operating, the thermodynamic electromotive force and polarization overpotential of a single cell are calculated using the steady-state output model in step S22 according to the indoor test results of the fuel cell. The polarization overpotential includes activation polarization overpotential, ohmic polarization overpotential, and concentration polarization overpotential. The output voltage of the fuel cell is calculated based on the thermodynamic electromotive force and polarization overpotential: ； Where V represents the output voltage of the fuel cell, E N represents the thermodynamic electromotive force, Vact, Vohm and Vcon represent the activation polarization overpotential, ohmic polarization overpotential and concentration polarization overpotential respectively; Step S22: Establish a steady-state output model of the fuel cell, so that the steady-state output model satisfies: ； Where V0 represents the test voltage value of the fuel cell, T is the current temperature, T0 is the test temperature, s0 is the standard molar entropy change, F is the Faraday constant, R is the gas constant, P H2 、P O2 and P H2O Represent the pressures of hydrogen, oxygen and water vapor respectively, i represents the current density, i0 represents the critical current density of the exchange membrane, Rc and Rm represent the equivalent impedance of the electrode and the exchange membrane respectively, i max represents the maximum value of current density; Step S23. Adding different amounts of catalyst to participate in the reaction, measuring the current density, and fitting the functional relationship between the amount of catalyst and the current density so that the current density satisfies: i = F(a), where a represents the amount of catalyst, and F(a) represents the effect of the catalyst on the current density; The current density is multiplied by the output voltage to obtain the functional relationship P(a) between the amount of catalyst involved and the battery output power, which satisfies P(a)=i·e·V, where e is the electron charge.

2. The hydrogen fuel cell energy management method for a hydrogen-powered UAV according to claim 1, characterized in that: Step S1 includes: Step S11. Set up sealed compartments within the fuel cell. Fill the compartment leading to the anode flow field plate with hydrogen fuel, and the compartment leading to the cathode flow field plate with oxygen or air. The compartment connected to the current collecting plate is used to collect water vapor products. All compartments are equipped with pressure valves that connect each compartment to the reactor and read the gas pressure within the compartments. Step S12. Add catalyst layers on both sides of the proton exchange membrane in the hydrogen fuel cell reactor. The catalysts used in the catalyst layers include carbon-supported platinum catalysts and Pt-M / C alloy catalysts. The catalyst layers are scalable. By adjusting the volume of the catalyst layer entering the fuel cell stack, the amount of catalyst involved is controlled, thereby controlling the reaction activity of the fuel cell.

3. The hydrogen fuel cell energy management method for a hydrogen-powered UAV according to claim 2, characterized in that: Step S3 includes: Step S31. The total mass of the UAV is obtained by adding the dynamic mass of the fuel cell and the mass of the UAV body to calculate the dynamic mass of the hydrogen fuel cell: ； Where M represents the dynamic mass of the fuel cell, Ef represents the fixed mass of the battery system, pH represents the hydrogen density at the current pressure, DH represents the fuel stack reaction density of hydrogen, σ1 represents the maximum hydrogen release rate of the hydrogen compartment, and σ2 represents the hydrogen conversion efficiency; Step S32: Obtain the flight parameters of the UAV, including the thrust, speed, and altitude of the UAV, and determine the power required for the UAV's flight: ； Among them, PW is the flight power required by the UAV, M0 is the mass of the UAV body, Cd and Cu represent the drag coefficient and lift coefficient respectively, g is the acceleration of gravity, p is the air density, S is the equivalent area of the wing, μ is the battery efficiency, and Pd is the additional power demand.

4. The hydrogen fuel cell energy management method for a hydrogen-powered UAV according to claim 3, characterized in that: Step S4 includes: Step S41: Obtain the flight command from the controller. Based on the changes in the drone's speed and altitude caused by the flight command, calculate the power required for the drone to execute the flight command in the next sequence. Add this to the flight power required for the current sequence to obtain the total power required for the next sequence. Step S42: Let P(a) = the total power required for the next time series, solve for the theoretical value of the catalyst loading a, and adjust the volume of the current catalyst layer entering the stack so that the catalyst loading equals the theoretical value. Step S5 includes: Step S51: The output power is converted into the engine speed of the UAV through a DC-DC converter. When the theoretical value of the catalyst participation exceeds the adjustment range of the catalyst layer, it is determined that the battery power is insufficient; Step S52. Calculate the adjustment amount of the oxygen partial pressure to increase the thermodynamic electromotive force of the fuel cell so that the theoretical value of the catalyst participation amount falls back into the adjustment range of the catalyst layer, use water vapor to compress the oxygen chamber, or use auxiliary energy to electrolyze water vapor to increase the air pressure in the oxygen chamber.

5. A hydrogen fuel cell energy management system for hydrogen-powered drones, characterized in that: The system includes the following modules: fuel cell module, catalytic control module, drone attitude module, reaction power module and hydrogen-oxygen cycle module; The fuel cell module consists of a hydrogen tank, an oxygen tank, a fuel reactor, and a water vapor circulation tank. The hydrogen tank is used to store hydrogen fuel, the oxygen tank is used to absorb oxygen from the outside, and the water vapor circulation tank is used to collect byproducts obtained after battery combustion. A pressure valve is used to connect the hydrogen tank, oxygen tank, and water vapor circulation tank to read the air pressure in each chamber in real time. At the same time, the fuel cell chips are connected in series, and a DC-DC converter is used to connect the battery output terminal to the drone engine. The catalytic control module is used to add a catalyst layer between the cathode and anode diffusion layers of the hydrogen fuel cell, and control the reaction activity of the fuel cell by adjusting the amount of catalyst involved. When the fuel cell is operating, the thermodynamic electromotive force and polarization overpotential of a single cell are calculated based on the gas pressure of each compartment and the reaction activity, and a steady-state output model of the fuel cell is established. Based on the steady-state output model and catalytic test results, a functional relationship between the amount of catalyst involved and the output power of the hydrogen fuel cell is obtained, and a correlation function between the output power of the fuel cell and the amount of catalyst involved is obtained by fitting; The UAV attitude module is used to obtain the flight parameters of the UAV, determine the thrust, speed and climbing altitude of the UAV, and receive control signals from the UAV control terminal. The dynamic mass of the energy system is calculated based on the initial weight of the fuel cell, hydrogen storage density, hydrogen tank pressure and reaction energy density. Based on the total mass and flight parameters of the UAV, the power required for the UAV flight and the power required for the next time sequence action are calculated. The total mass is the sum of the dynamic mass of the fuel cell and the mass of the UAV body. The reaction power module is used to convert the output power into the engine speed of the drone through a DC-DC converter. Based on the efficiency of the speed governor, motor and propeller, the output power of the fuel cell is determined so that the total power required by the drone in the next time sequence is the same as the output power of the engine. The correlation function between the output power of the fuel cell and the amount of catalyst participation is substituted into the function to obtain the amount of catalyst participation, and the volume of the catalyst layer in the reactor is adjusted according to the amount of catalyst participation. The hydrogen-oxygen circulation module is used to calculate the oxygen partial pressure when the speed increase rate is the highest when the battery power is insufficient, pressurize the gas in the water vapor circulation chamber and input it into the oxygen chamber, pressurize the oxygen chamber by mechanical compression or auxiliary energy compression, and adjust the oxygen pressure to maximize the output power of the fuel cell.

6. The hydrogen fuel cell energy management system for a hydrogen-powered UAV according to claim 5, characterized in that: The fuel cell module includes: a pressurized chamber unit and a fuel stack unit; The pressurized cabin unit is used to read the pressure of the hydrogen cabin, oxygen cabin and water vapor circulation cabin, and connect the oxygen cabin and water vapor circulation cabin to adjust the oxygen supply pressure; The fuel stack unit is used to provide a reaction space for the fuel cell and simultaneously connect the battery cells in series to obtain a higher output voltage.

7. The hydrogen fuel cell energy management system for a hydrogen-powered UAV according to claim 6, characterized in that: The catalytic control module includes: a catalyst layer unit, a polarization output unit and a power feedback unit; The catalyst layer unit is used to accelerate the reaction rate of the fuel cell using platinum as a catalyst, and the amount of catalyst involved is controlled by controlling the insertion ratio of the platinum layer; The polarization output unit is used to calculate the thermodynamic electromotive force, activation polarization overpotential, ohmic polarization overpotential and concentration polarization overpotential of a single battery; The power feedback unit is used to establish a steady-state output model of the fuel cell and calculate a correlation function between the output power of the fuel cell and the amount of catalyst involved.

8. The hydrogen fuel cell energy management system for a hydrogen-powered UAV according to claim 7, characterized in that: The UAV attitude module includes: an attitude sensing unit, a dynamic mass unit and a timing requirement unit; The attitude sensing unit is composed of a gyroscope, an airspeed meter and an altimeter in the UAV, and is used to obtain the flight parameters of the UAV; The dynamic mass unit is used to calculate the real-time mass of the hydrogen fuel cell and the real-time flight power of the UAV; The timing demand unit is used to receive the flight instructions of the controller to the UAV and determine the dynamic power demand of the UAV at the next moment.

9. The hydrogen fuel cell energy management system for a hydrogen-powered UAV according to claim 8, characterized in that: The reaction power module includes: a reaction adjustment unit and a speed matching unit; The reaction adjustment unit is used to adjust the amount of catalyst involved according to the total power demand of the next time sequence of the UAV; The speed matching unit is used to fit the relationship between the UAV engine speed and the battery output power to determine the battery power requirement of the UAV at the next moment; The hydrogen and oxygen circulation module includes: a partial pressure measurement unit and a cabin pressurization unit; The partial pressure measuring unit is used to calculate the magnitude of the oxygen partial pressure when the engine speed increases at the maximum speed; The cabin pressurizing unit is used to compress the oxygen cabin using water vapor, or to electrolyze water vapor using auxiliary energy to increase the air pressure in the oxygen cabin.

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