US-12617544-B2 - Method for determining at least one power limit of a hybrid drive train for a transport vehicle, in particular an aircraft

US12617544B2US 12617544 B2US12617544 B2US 12617544B2US-12617544-B2

Abstract

A method for determining at least one minimum power margin of a hybrid drive train for a transport vehicle, each drive element being associated with at least one power source and at least one power consumer. The method including a step of acquiring measurements of power parameters, a step of comparing each measurement with at least one limitation threshold, so as to deduce therefrom at least one gross margin, a step of converting the gross margins into refined margins expressed according to the same common magnitude, a step of transposing into standardised margins at least at one reference point, a step of determining a source power margin and a consumer power margin at said reference point and a step of determining the minimum power margin by selecting the lowest power margin.

Inventors

David Bernard Martin LEMAY
Jean-Philippe Jacques MARIN

Assignees

SAFRAN HELICOPTER ENGINES

Dates

Publication Date: 20260505
Application Date: 20211108
Priority Date: 20201110

Claims (10)

1 . A method for determining at least one minimum power margin of a hybrid drive train for an aircraft, the hybrid drive train comprising a plurality of power sources of different natures, a plurality of power consumers and a plurality of drive elements, each of the plurality of drive elements being associated with at least one of the plurality of power sources and at least one of the plurality of power consumers, the method comprising: acquiring measurements of a plurality of power parameters of the hybrid drive train using a calculator, at least two of the measurements being expressed according to different units of measure, comparing each of the measurements with at least one limitation threshold, determined respectively for each of the plurality of power parameters from a threshold database using the calculator, in order to deduce therefrom at least one gross power margin for each of said plurality of power parameters, converting from a transformation database including a transformation ratio database, the at least one gross power margin of said plurality of power parameters into refined power margins expressed according to a same common unit of measure using the calculator, transposing from a yield database, the refined power margins into standardized power margins at an at least one reference point of the hybrid drive train using the calculator, the yield database storing predetermined yield ratios for a plurality of transmission members including at least an electric generator configured to convert mechanical power from a turbogenerator to electrical power, at least one rectifier configured to convert alternating current to direct current, at least one electrical channel configured to transport electrical power, at least one inverter configured to convert direct current to alternating current, and at least one electric motor configured to convert electrical power to mechanical power, wherein the yield database determines yields of the plurality of transmission members that are between an acquisition point and the at least one reference point by multiplying the predetermined yield ratios of the plurality of transmission members that are between the acquisition point and the at least one reference point, determining a source power margin, from the standardized power margins of the plurality of power sources at said at least one reference point, and a consumer power margin, from the standardized power margins of the plurality of power consumers at said reference point using the calculator, determining the minimum power margin by selecting a lowest power margin between the consumer power margin and the source power margin at said at least one reference point using the calculator, and controlling the plurality of transmission members of the hybrid drive train for the aircraft based on the selected lowest power margin.
2 . The method according to claim 1 , wherein the at least one reference point corresponds to one or more of the plurality of drive elements.
3 . The method according to claim 1 , wherein when the plurality of power sources supply several of the plurality of power consumers in parallel, it is assumed that a total power received in a node is equally distributed among the plurality of power consumers.
4 . The method according to claim 1 , wherein when the plurality of power sources supply several of the plurality of power consumers in parallel, a total power received in a node is distributed in a weighted manner among the plurality of power consumers.
5 . The method according to claim 1 , wherein the plurality of power sources comprises at least one turbogenerator and at least one electric battery.
6 . The method according to claim 1 , wherein the hybrid drive train comprises a plurality of electric motors as the plurality of power consumers.
7 . The method according to claim 1 , wherein for the aircraft, the individual power margins are grouped along main axes of the aircraft so as to indicate roll, pitch, and yaw margins.
8 . A method of controlling an aircraft, comprising a hybrid drive train, by means of a control system, the method comprising: determining a control order of the aircraft by the control system, the control order being associated with a power requirement, determining the at least one minimum power margin of the hybrid drive train by the method according to claim 1 , and validating the control order if the power requirement is less than the minimum power margin.
9 . A hybrid drive train for an aircraft, the hybrid drive train comprising a plurality of power sources, a plurality of power consumers and a plurality of drive elements, each of the plurality of drive elements being associated with at least one of the plurality of power sources and at least one of the plurality of power consumers, the hybrid drive train comprising at least one calculator and databases accessible by the calculator, the calculator being configured to: acquire measurements of a plurality of power parameters of the hybrid drive train, at least two of the measurements being expressed according to different units of measure, compare each of the measurements with at least one limitation threshold, determined respectively for each of the plurality of power parameters from a threshold database, so as to deduce therefrom at least one gross power margin for each of said plurality of power parameter, convert from a transformation database including a transformation ratio database, the gross power margins of each of said plurality of power parameters into refined power margins expressed according to a same common unit of measure, transpose from a yield database, the refined power margins into standardized power margins at an at least one reference point, the yield database storing predetermined yield ratios for a plurality of transmission members including at least an electric generator configured to convert mechanical power from a turbogenerator to electrical power, at least one rectifier configured to convert alternating current to direct current, at least one electrical channel configured to transport electrical power, at least one inverter configured to convert direct current to alternating current, and at least one electric motor configured to convert electrical power to mechanical power, wherein the yield database determines yields of the plurality of transmission members that are between an acquisition point and the at least one reference point by multiplying the predetermined yield ratios of the plurality of transmission members that are between the acquisition point and the at least one reference point, determine a source power margin, from the standardized power margins of the plurality of power sources at the said the at least one reference point, and a consumer power margin, from the standardized power margins of the plurality of power consumers at said at least one reference point, determine the minimum power margin by selecting a lowest power margin between the consumer power margin and the source power margin at said at least one reference point, and controlling the plurality of transmission members of the hybrid drive train based on the selected lowest power margin.
10 . The aircraft, comprising: the at least one hybrid drive train according to claim 9 .

Description

TECHNICAL FIELD The present invention relates to the field of hybrid drive of a transport vehicle, in particular an aircraft. In a known manner, it has been proposed to equip an aircraft with a hybrid drive train comprising several different power sources to drive a plurality of drive elements, in particular, at least one turbomachine and at least one electric battery. Such a hybrid drive train enables an aircraft to transport goods and merchandise in an optimal way while limiting noise pollution and fuel consumption while improving safety. As an example, in reference to FIG. 1, an aircraft 1 comprising a hybrid drive train 2 comprising four drive elements H1-H4 is generally represented, in particular propellers. Each drive element H1-H4 is connected to two electric motors to allow the driving thereof: a primary motor M1A-M4A and a secondary motor M1B-M4B. As shown in FIG. 1, the primary motors M1A-M4A are electrically connected to a primary battery BATA via a primary channel CA while the secondary motors M1B-M4B are electrically connected to a secondary battery BATB via a secondary channel CB. The hybrid drive train 2 comprises a turbogenerator TG, comprising a gas turbomachine, to electrically supply the electric motors M1A-M4A, M1B-M4B and the batteries BAT, BATB via the channels CA, CB. In this example, the drive is referred to as a series hybrid. In a known manner, a hybrid drive train 2 may adopt different architectures, in particular: a series architecture wherein the gas turbomachine only produces electrical power (turbogenerator) to supply the channels and recharge the batteries.a parallel architecture wherein the gas turbomachine produces only mechanical power to drive drive elements. The electrical power is provided by batteries that may be recharged by the electric machines that are then used both as a motor and as a generator.a series and parallel architecture wherein the power produced by the gas turbomachine is used both in mechanical form to drive drive elements and in electrical form to power electric motors or recharge batteries. This architecture incorporates features of series hybridization and parallel hybridization. Each hybrid drive train has power limitations that depend on many parameters, in particular, its architecture, the maximum torque on the gas turbomachine, the maximum alternating current of the turbogenerator, the maximum current supplied to a channel during electrical generation, the maximum electric current that the battery may deliver, the maximum electric current at which a drive motor may operate, etc. In other words, it is difficult to determine a power limit for the hybrid drive train. In addition, a hybrid drive train 2 is also designed to operate in several configurations to compensate for the failures of certain energy sources. As an example, the hybrid drive train may be operated according to: a nominal configuration with all available sources, capable of supplying part of the power demand.a configuration on batteries BATA, BATB only in case of failure of the turbogenerator TG.a configuration on turbogenerator TG in case of failure of a battery BATA, BATB. On any aircraft, the supply of the power required by the pilot (human or automatic) is highly critical for flight safety since it is what provides the levitation of the aircraft. This critical nature is further accentuated on a VTOL type aircraft (vertical take-off/landing aircraft) because the power developed by each drive element contributes not only to the levitation, but also to the control of the attitude of the aircraft and therefore directly to the stability of the flight. Compliance with these power demands may, in certain cases, come into conflict with certain performance limits of the drive train. When this situation occurs, the drive train may no longer satisfy the demand and may either protect itself by continuing to provide a service but limiting the power delivered, or follow the power demand until triggering a protection device which potentially leads to a partial or total power cut-off. Whatever the behavior of the drive train, the pilot may be “surprised” by the refusal (or loss) to deliver the power demand. This may be detrimental if the latter is carrying out a “complex” or critical maneuver. Indeed, the latter may hardly compensate for the lack of power, which would have the consequence of affecting flight safety. To eliminate this disadvantage, an immediate solution consists in oversizing the power capacity of the drive train in order to have a large safety margin in all conditions of use and all configurations. Such a solution cannot be retained because it impacts the mass of the drive train and therefore reduces the mass embarkable by the aircraft. One of the objectives of the present invention is to enable the pilot (human or automatic) to permanently determine the available power margin of the hybrid drive train in order to be able to determine the control commands that may be carried o