Method for managing the energy of a hybrid aircraft propulsion system

Abstract

Method for managing the energy of a hybrid aircraft propulsion system Method (200) for managing the energy supplied by a hybrid aircraft propulsion system, the hybrid propulsion system comprising at least one heat engine, one electric motor, and a main power transmission box configured to rotate a rotor of the aircraft, the heat and electric motors being configured to supply mechanical power to the main transmission box, the management method comprising at least: a determination (210) of a maximum threshold (Seuil_max(z)) of sound or gas emissions as a function of a height (z) between the aircraft and the ground; a determination (220) at a time t of a sound or gas emission (Emission(t));if the sound or gas emission at time t is greater than the determined maximum threshold, a determination (230) of a distribution of the mechanical power (Cons1, Cons2) supplied by the thermal and electric engines to the main power transmission box so that a next sound or gas emission at time t+1 (Emission(t+1)) is less than or equal to the determined maximum threshold. Figure for the abstract: Fig. 2;

Description

Title of the invention: Method for managing the energy of a hybrid aircraft propulsion system Technical field

[0001] The present invention relates to the general field of aircraft hybridization, and more particularly to the management of energy provided by electrical sources and thermal sources for the propulsion of an aircraft. Prior art

[0002] Climate change is a major concern for many legislative and regulatory bodies around the world. Indeed, various restrictions on carbon emissions have been, are being or will be adopted by various states. In particular, an ambitious standard applies both to new types of aircraft but also to those currently in circulation requiring the implementation of technological solutions in order to make them compliant with current regulations. Civil aviation has been mobilizing for several years now to make a contribution to the fight against climate change.

[0003] Technological research efforts have already made it possible to significantly improve the environmental performance of aircraft. The Applicant takes into consideration the impact factors in all phases of design and development to obtain less energy-intensive, more environmentally friendly aeronautical components and products whose integration and use in civil aviation have moderate environmental impacts with the aim of improving the energy efficiency of aircraft.

[0004] Consequently, the Applicant is constantly working to reduce its climate impact by using methods and operating virtuous development and manufacturing processes and minimizing greenhouse gas emissions to the minimum possible in order to reduce the environmental footprint of its activity.

[0005] This sustained research and development work covers new generations of aircraft engines, the lightening of aircraft, in particular through the materials used and lighter on-board equipment, the development of the use of electrical technologies to ensure propulsion, and, as essential complements to technological progress, aeronautical biofuels.

[0006] In this context, the aeronautics industry is particularly committed to reducing its noise and gaseous pollutant emissions, particularly in urban areas. These emissions include global pollutants, such as carbon dioxide, and local pollutants, such as noise or nitrogen oxide.

[0007] The need for managing polluting emissions comes from the constraint of severely limited electrical energy. Current technology in energy storage systems offers very low energy densities compared to fossil fuels, which severely limit the amount of energy on board the aircraft. This limitation therefore requires controlling electrical energy consumption as precisely as possible.

[0008] It is therefore desirable to have a new method for managing the energy of a hybrid aircraft propulsion system to best distribute the supply of propulsive power between carbon and decarbonized sources in order to reduce local noise and gaseous pollutant emissions. Statement of the invention

[0009] To this end, the invention is the result of technological research aimed at very significantly improving the performance of aircraft, and in this sense, contributes to reducing the environmental impact of aircraft. For this purpose, the invention relates to a method for managing the energy supplied by a hybrid aircraft propulsion system, the hybrid propulsion system comprising at least: - a heat engine; - an electric motor; and - a main power transmission box configured to rotate a rotor of the aircraft, the thermal and electric motors being configured to provide mechanical power to the main transmission box,

[0010] the management method comprising at least: - a determination of a maximum threshold of noise or gas emissions based on a height between the aircraft and the ground and a specific geographical area and / or geolocation data; - a determination at a time t of a sound or gas emission; - if the sound or gas emission at time t is greater than the maximum threshold determined, a determination of a distribution of the mechanical power supplied by the thermal and electric motors to the main power transmission box so that a next sound or gas emission at a time t+1 is less than or equal to the determined maximum threshold.

[0011] Thanks to the method according to the invention, it is possible to more precisely control the distribution of propulsive power between the carbon source (thermal engine), emitting gaseous pollutants and noise, and the decarbonized source (electric motor) when approaching or moving away from the ground in order to reduce local gaseous and / or noise pollutant emissions.

[0012] Furthermore, as the maximum gas and noise emission thresholds not to be exceed are determined based on the height between the ground and the aircraft and a specific geographical area and / or geolocation data, it is easier to adapt to the local constraints of the area flown over. Thus, during takeoff, the maximum thresholds can be increased gradually as you move away from the ground; or, to force landing, the maximum threshold values ​​will be reduced as you approach the ground in order to limit local pollution.

[0013] Thus, we will seek to maximize the mechanical power supplied by the electric motor close to the ground, and we will increase the share of mechanical power supplied by the thermal engine by moving away from the ground.

[0014] According to a particular characteristic of the invention, the sound or gas emission and the corresponding maximum threshold are chosen from the following quantities: noise, a nitrogen oxide emission rate, a carbon oxide emission rate, a smoke emission rate, or a carbon hydroxide emission rate.

[0015] According to another particular characteristic of the invention, the method also comprises a step of acquiring data representative of safety and / or environmental constraints, the maximum threshold of sound or gas emissions also being a function of these acquired data. The data representative of environmental and / or safety constraints may for example be based on geolocation data.

[0016] This step of acquiring data representative of environmental and / or safety constraints makes it possible to take into account the fact that, for the same height between the ground and the aircraft, the maximum thresholds determined will not necessarily be the same between two different zones. Indeed, near a city or a protected environmental zone, the maximum thresholds determined may be lower than those determined near an airport far from a city.

[0017] According to one embodiment of the invention, the determination of the maximum threshold is carried out in real time during a flight of the aircraft.

[0018] This makes it possible to adapt as precisely as possible to the aircraft's environment.

[0019] According to another embodiment of the invention, the determination of the maximum threshold is carried out before takeoff of the aircraft.

[0020] This makes it possible to more accurately predict the amount of carbon energy needed during the flight, and to avoid carrying more fuel than necessary.

[0021] According to a particular characteristic of the invention, the maximum threshold determined is also a function of an ambient temperature around the aircraft and / or an atmospheric pressure around the aircraft and / or the fuel flow supplied to the heat engine.

[0022] It may also depend on a rotation speed of a gas generator and / or a gas temperature at the inlet of an aircraft turbine.

[0023] According to another particular characteristic of the invention, the height between the aircraft and the ground is an average of the heights between the ground and the aircraft over a given distance.

[0024] According to another particular characteristic of the invention, the method also comprises a determination of a constraint level of the determined maximum threshold, and in which the steps of the method are repeated for another quantity of sound or gas emissions and the distribution of the mechanical power being determined as a function of the determined constraint levels.

[0025] This makes it possible to prioritize certain constraints if it is not possible to determine a power distribution between the electric and thermal engines that allows one to remain below all the maximum thresholds determined to best adapt to the areas flown over by the aircraft. For example, one can choose to prioritize the constraints related to gas pollution over noise pollution above certain areas, or on the contrary, prioritize the constraints related to noise pollution over gas pollution above other areas. One can also prioritize, for example, the constraints related to the emission of nitrogen oxide over the emission of carbon dioxide.

[0026] Another object of the invention is an aircraft comprising: - a hybrid propulsion system comprising a thermal engine, an electric motor, a main power transmission box supplied with mechanical power by the thermal engine and the electric motor, - an electrical source configured to power the electric motor, - a fuel tank configured to power the thermal engine, - a rotor driven in rotation by the main gearbox of the hybrid propulsion system, - an electric motor control device; - a thermal engine control device, and - a computer configured to implement the management method according to the invention and transmit an instruction for the distribution of the determined mechanical power to the electric motor control device and to the thermal engine control device.

[0027] According to a particular characteristic of the invention, the aircraft also comprises a means for measuring a height between the aircraft and the ground and a determined geographical area and / or geolocation data. Brief description of the drawings

[0028] Other characteristics and advantages of the present invention will emerge from the description given below, with reference to the appended drawings which illustrate examples of realization without any limiting character.

[0029] [Fig. 1] [Fig.l] schematically and partially represents a hybrid propulsion system of an aircraft according to one embodiment.

[0030] [Fig.2] [Fig.2] represents, schematically and partially, the energy management method according to an embodiment of the invention implemented in the hybrid propulsion system of [Fig.l].

[0031] [Fig.3] [Fig.3] represents, schematically and partially, an example of maximum thresholds for noise and / or gas emissions as a function of the height between the ground and the aircraft. Description of the embodiments

[0032] [Fig.l] represents a hybrid power plant 100 capable of implementing the management method according to the invention, one embodiment of which is represented schematically in [Fig.2].

[0033] The installation 100 comprises a fuel tank 120, an electrical source 150 and a hybrid propulsion system comprising an electric motor 140, a thermal engine 110 and a main power transmission box 130.

[0034] The fuel tank 120 supplies fuel to the thermal engine 110, while the electrical source 150 supplies electricity to the electric motor 140. The electric motor 140 and thermal motor 110 supply mechanical power to the transmission box 130 which rotates a rotor 170.

[0035] A computer 160 implements the method 200 of the invention and provides power distribution instructions between the two engines 110 and 140 via their respective control devices 161, 162. The computer 160 can be the electrical management means of the hybridization of the propulsion system which can be managed by the aircraft controller or by a dedicated controller.

[0036] The hybrid power plant 100 may also comprise a means for measuring a height between the ground and the aircraft which communicates this data to the computer 160.

[0037] The means for measuring a height between the ground and the aircraft is for example a radio altimeter, and / or a three-axis GPS system, and / or an ADIRS system (“Air Data Inertial Referenced System”) and / or an atmospheric pressure sensor measuring the height by pressure difference between the pressure measured on the ground before takeoff and the pressure measured in real time.

[0038] The method 200 comprises a step 210 of determining a maximum threshold Threshold_max(z) of sound or gas emissions as a function of the height z between the aircraft (i.e. between the hybrid power plant 100) and the ground; as well as a step 220 of determining at a time t a sound or gas emission Emission(t).

[0039] The sound or gas emission Emission(t) as well as the associated maximum threshold Seuil_max(z) represents a quantity chosen from: noise, a nitrogen oxide emission rate, a carbon oxide emission rate, a smoke emission rate, or a carbon hydroxide emission rate.

[0040] The quantity or quantities chosen may correspond to an hourly emission rate, more particularly in decibels per minute for noise, or in grams per minute for gaseous emissions. They may also correspond to an emission rate relative to the mass of the aircraft or relative to the total engine power, to a percentage of the maximum threshold, or even to a limit in “absolute” quantity of emission below a determined height expressed for example in grams for gaseous emissions.

[0041] [Fig.3] represents an example of maximum threshold Seuil_max(z) as a function of the height z between the ground and the aircraft. In this example, for a height less than Hl, the maximum threshold is equal to SI, then between heights Hl and H2, it varies linearly until reaching D2; then between heights H2 and H3, it is equal to S2; between heights H3 and H4, it varies linearly until reaching S3 and finally for heights greater than H4, it is equal to S3. The maximum threshold Seuil_max(z) can also vary between heights Hl and H2 in a non-linear manner such as for example exponentially or logarithmically.

[0042] This maximum threshold Threshold_max(z) can be determined from a combustion model of the heat engine 110 before the flight of the aircraft, or in real time during the flight. In addition, it can also depend on the controlled or measured fuel flow rate which is injected into the heat engine 110, and / or the atmospheric pressures and temperatures, and / or the main operating parameters of the heat engine 110, such as for example the rotation speed of the gas generator or the temperature of the gases at the inlet of the turbine.

[0043] The maximum threshold Seuil_max(z) can still be determined from data representative of safety and / or environmental constraints acquired during the flight.

[0044] The height z between the ground and the aircraft may be the actual height or an average of the heights over a given distance. For example, when the aircraft flies over a mountainous area or a canyon, it is preferential to use an average of the heights over the entire flyover area, so that the maximum threshold is constant, rather than using a variable maximum threshold.

[0045] Finally, if the emission determined in real time Emission(t) is greater than the maximum threshold determined Threshold_max(z), the method 200 determines, during step 230, a hybridization instruction so that the next emission determined at time t+1 Emission(t+1) is less than or equal to the maximum threshold Threshold_max(z).

[0046] The determined hybridization instruction is a distribution instruction Consl, Cons2 of the mechanical power to be supplied to the main power transmission box 130 from the thermal 110 and electric 140 engines. This setpoint Consl, Cons2 calculated by the computer 160 is transmitted to the control device 162 of the thermal engine 110 and to the control device 161 of the electric motor 140. Thus the thermal 110 and electric 140 engines will supply for the time t+1 mechanical powers to the transmission box 130 allowing to remain below the maximum threshold Threshold_max(z) determined in step 210. In areas where the margin with respect to the determined maximum threshold Threshold_max(z) is significant, it is possible to define a battery recharging setpoint in order to reach the maximum threshold. In this case the setpoint Cons 1 is negative.

[0047] The method 200 can also be repeated for several types of noise or gas emissions. For example, if it is desired to reduce both noise pollution and gas pollution linked to the emission of nitrogen oxide, the steps of the method 200 are carried out for both types of emission and the method 200 may also comprise a step of determining a constraint level of the two maximum thresholds determined. This makes it possible to determine which will be the most important threshold to respect if it is not possible to determine a hybridization instruction making it possible to verify both that the next noise emission at t+1 is lower than the first maximum threshold linked to noise and that the next nitrogen oxide emission at t+1 is lower than the second maximum threshold linked to nitrogen oxide.

[0048] More generally, the method 200 may comprise a step of determining a constraint level of the determined maximum threshold and repeating steps 210 to 230 as many times as there are types of sound or gas emissions determined.

Claims

Claims

1. Method (200) for managing the energy supplied by a hybrid propulsion system of an aircraft, the hybrid propulsion system comprising at least: - a heat engine (110); - an electric motor (140); and - a main power transmission box (130) configured to rotate a rotor (170) of the aircraft, the heat and electric motors being configured to supply mechanical power to the main transmission box, the management method comprising at least: - a determination (210) of a maximum threshold (Seuil_max(z)) of sound or gas emissions as a function of a height (z) between the aircraft and the ground and of a determined geographical area and / or of geolocation data; - a determination (220) at a time t of a sound or gas emission (Emission(t));- if the sound or gas emission at time t is greater than the determined maximum threshold, a determination (230) of a distribution of the mechanical power supplied by the thermal (Cons2) and electric (Consl) engines to the main power transmission box so that a next sound or gas emission at time t+1 (Emission(t+1)) is less than or equal to the determined maximum threshold.;

2. Method according to claim 1, in which the sound or gas emission and the corresponding maximum threshold are chosen from the following quantities: noise, a nitrogen oxide emission rate, a carbon oxide emission rate, a smoke emission rate, or a carbon hydroxide emission rate.

3. Method according to any one of claims 1 or 2, also comprising a step of acquiring data representative of safety and / or environmental constraints, the maximum threshold of sound or gas emissions also being a function of these acquired data.

4. Method according to any one of claims 1 to 3, in which the determination of the maximum threshold is carried out in real time during a flight of the aircraft.

5. Method according to any one of claims 1 to 3, in which the determination of the maximum threshold is carried out before takeoff of the aircraft.

6. Method according to any one of claims 1 to 5, in which the determined maximum threshold is also a function of an ambient temperature around the aircraft and / or an atmospheric pressure around the aircraft and / or the fuel flow supplied to the heat engine.

7. A method according to any one of claims 1 to 6, wherein the height between the aircraft and the ground is an average of the heights between the ground and the aircraft over a given distance.

8. A method according to any one of claims 1 to 7, further comprising a determination of a determined maximum threshold stress level, and wherein the method steps are repeated for another magnitude of sound or gas emissions and the distribution of mechanical power is determined as a function of the determined stress levels.

9. Aircraft comprising: - a hybrid propulsion system comprising a heat engine (110), an electric motor (140), a main power transmission box (130) supplied with mechanical power by the heat engine and the electric motor, - an electrical source (150) configured to supply the electric motor, - a fuel tank (120) configured to supply the heat engine, - a rotor (170) driven in rotation by the main transmission box of the hybrid propulsion system, - a control device (161) of the electric motor; - a control device (162) of the heat engine, and - a computer (160) configured to implement the management method (200) according to any one of claims 1 to 8 and transmit a setpoint (Consl, Cons2) of the distribution of mechanical power determined to the electric motor control device and to the thermal engine control device.

10. Aircraft according to claim 9, also comprising means for measuring a height between the aircraft and the ground and a determined geographical area and / or geolocation data.

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