Training method for handling a failure of a power system affecting a hybrid propulsion system

Abstract

The invention relates to a method for training a pilot to handle a failure affecting a power system of a hybrid propulsion system of an aircraft, the hybrid propulsion system comprising n power systems (n > 2) connected in parallel on a transmission unit, the n power systems comprising a first power system and a second power system which are intrinsically different. The method comprises simulating a failure affecting the first power system during a flight of the aircraft, checking the state of the n power systems of the propulsion system while the simulation is performed. If a failure affecting one of the n propulsion systems is detected, the simulation is stopped and the instantaneous power provided by at least one of the first or second power systems is increased so that the sum of the instantaneous powers provided by the n power systems is greater than the minimum total instantaneous power required for the aircraft to continue flying.

Description

Technical Field

[0001] The present invention relates to a method for assisting training aircraft pilots in handling malfunctions that affect the power systems of at least two redundant parallel power systems in an aircraft equipped with a redundant hybrid propulsion system.

[0002] This invention is applicable to the propulsion and lift systems of fixed-wing aircraft, rotary-wing aircraft (helicopters), or vertical take-off and landing aircraft (VTOL). Background Technology

[0003] Techniques for simulating engine failures to train pilots of twin-engine (or tri-engine) helicopters have been available for many years.

[0004] The principle of simulating engine failure affecting a multi-engine helicopter is known, including reducing the power of two (or more) engines to the level of emergency maximum power that a single engine (or an engine that remains available after a failure affecting one of the engines) can provide (the so-called OEI / 2 simulation method, which stands for "One Engine Inoperative").

[0005] A method for enabling aircraft pilots to resolve faults affecting one or more engines of a multi-engine aircraft in flight is known from reference [1]. The software simulates an engine fault by using an output power limit imposed by the software on the engine that is simulated as faulty. For example, in the case of two engines, an imbalance is created between the two engines by causing the engine that is simulated as operating to reach its continuous maximum power (or OEIC power, which stands for "One Engine Inoperative Continuous") when a fault occurs affecting the other engine and the other engine simulated as faulty provides supplement to the rotor (so-called significantly lower level).

[0006] A method and system for simulating the condition of a failed engine in a multi-engine aircraft (OEI method) is known from reference [2], which involves the engines operating above a non-zero power setting, with each engine operating relative to each other, to simulate the power loss experienced during an actual failure affecting at least one engine. More specifically, the transient power loss experienced by the pilot when a real engine failure occurs is simulated by transiently limiting the power provided by both engines below their emergency maximum power.

[0007] Hybrid power unit management architectures and methods are also known, comprising one or more main engines and one or more auxiliary engines, designed to compensate for power losses in at least one main engine. References [3] and [4] address these solutions.

[0008] In the case of a hybrid propulsion system, a simple and well-known solution for training on handling engine failures is to set the same engine to idle, so that it provides almost no power to the rotor. The pilot can then receive flight training with only one (or more) remaining power systems available, which can be implemented by only one (or more) auxiliary engines of different nature from the engine simulated as failing (e.g., one (or more) electric motors).

[0009] Representative, but not limiting, examples of aircraft and their hybrid propulsion systems may include helicopters equipped with a main rotor and a tail rotor (referred to as anti-torque rotors).

[0010] The helicopter is equipped with a main propulsion system, which provides mechanical power to both rotors via a main engine and a main transmission unit (BTP). For example, the main engine can be a helicopter turboshaft engine; this main engine provides most of the power required for helicopter flight.

[0011] The helicopter is also equipped with an electric auxiliary power system, including:

[0012] - An electric motor provides mechanical power to both rotors via a second input on the BTP;

[0013] - Power and control electronics that can regulate the power supplied by the electric motor;

[0014] - Power distribution components; and

[0015] - The power source can be a battery.

[0016] This auxiliary power system is essentially designed to provide a minimum level of power to ensure a safe and rapid landing of the aircraft. Therefore, the maximum power available from the electric motors is significantly lower than that provided by the main engines. Consequently, the flight range and permissible maneuverability are very limited.

[0017] When a malfunction affects at least one of the aircraft's propulsion engines, especially in the case of a rotorcraft, the maximum available power is lower than that available under normal operating conditions (no malfunction). Piloting the aircraft becomes more complex, requiring specialized learning and training for pilots. Typically, this training includes "simulating" engine malfunctions during flight and requiring pilots to fly and land the aircraft under these descent conditions.

[0018] Technological advancements have enabled the introduction of hybrid propulsion systems, integrating one or more power systems that differ from one (or more) main engines. This is particularly true of electric or hydraulic power systems.

[0019] These power systems differ in nature from one (or more) main engines, and their size can be designed to provide power equivalent to or significantly less than the maximum power of one (or more) main engines; their basic function can be to provide emergency "backup" power in the event of a main engine failure.

[0020] The unique characteristic of these hybrid systems (compared to installing several identical engines) is that their maximum power mechanism and dynamic power variations can differ significantly from those of the main engine. Therefore, control ergonomics can be greatly affected in actual fault or fault training scenarios. Consequently, these training exercises should faithfully reflect these behavioral differences to represent real-world fault conditions.

[0021] Finally, a major drawback of the aforementioned training techniques for handling engine malfunctions (i.e., treating the engine as idling as a malfunction) is that, in the event of an actual malfunction affecting one of the remaining power systems during training, the reactivation and power-on time of the idling engine is very long. Therefore, flight safety can be significantly reduced in the few seconds following a malfunction affecting the power system.

[0022] Turboshaft engine manufacturers have developed so-called “CAA” (Civil Aviation Authority) training to address safety concerns, but this can sometimes compromise representativeness. Because the power of both engines is limited to OEI / 2, this training mode is also known as OEI / 2.

[0023] In summary, the present invention aims to provide solutions to the following problems:

[0024] - Allows pilots to fly in the presence of a faulty engine (i.e., when simulating a failure affecting a component of the propulsion or lift chain);

[0025] - By maintaining the simulation as an engine affected by a failure under the operating mechanism, it is made to have sufficient responsiveness when an actual failure affects the simulated operating power system, in order to ensure a high level of safety (in particular, it is necessary to be able to handle any actual failure affecting the power system during training without posing any danger to the aircraft, which involves the good responsiveness of the components of the power system that are still operating after an actual failure).

[0026] - In an aircraft equipped with a hybrid propulsion system, the hybrid propulsion system comprises n parallel power systems (n is an integer greater than or equal to 2), the n parallel power systems comprising at least one first power system and a second power system that are substantially different, the first power system and the second power system preferably having very different power and / or dynamic performance; in fact, by simulating a power loss equivalent to the maximum power of the first power system, all n chains will be used to simulate a failure affecting the first chain; for example, for orders of magnitude of the first power system and the second power system, in terms of power, the maximum power level of the second power system may be at least 30% lower than the maximum power level of the first power system, and in terms of dynamics, the dynamics of the second power system are at least twice that of the first power system;

[0027] - Each element of a power system (or more) remains active without overloading. Summary of the Invention

[0028] Therefore, the object of the present invention is a method for training pilots to handle malfunctions affecting the power system of a hybrid propulsion system of an aircraft, the aircraft including n power systems connected in parallel on a transmission unit, where n is an integer greater than or equal to 2, the n power systems including a first power system and a second power system that are substantially different, the method including, during flight of the aircraft, simulating malfunctions affecting the first power system by performing the following steps:

[0029] -The instantaneous power P provided by the first power system M1inst Reduced to training power P M1Ecol And maintain the power P M1Ecol Until the simulation ends, where:

[0030] P M2最大_OEI >P M1Ecol >P M1最小

[0031] P M2最大_OEI The instantaneous maximum power that the second power system can provide when not in training mode, and P M1最小 The minimum instantaneous power that the first power system can provide; and

[0032] -The instantaneous power P provided by the second power system M2inst Increase to below or equal to the upper limit power P applicable to the second power system during the training mode. M2lim_Ecol The power, and the adjustment of the power P during the simulation. M2inst This ensures that the instantaneous total power P provided by the first power system and the second power system in the training mode... tot_EcolLess than or equal to P M2最大_OEI ,in:

[0033] P tot_Ecol =P M1Ecol +P M2inst

[0034] P tot_Ecol ≤P M2最大_OEI

[0035] P M2inst ≤P M2lim_Ecol <P M2最大_OEI

[0036] P M2lim_Ecol +P M1Ecol =P M2最大_OEI

[0037] P M2lim_Ecol The second dynamic system in the training mode makes P tot_Ecol No more than P M2最大_OEI The maximum power that can be provided;

[0038] The method further includes: while performing the simulation, checking the status of the n power systems of the propulsion system; and if a fault affecting one of the n power systems is detected, stopping the simulation and increasing the instantaneous power provided by at least one of the first power system and the second power system, such that the sum of the instantaneous power provided by the n power systems is greater than or equal to P. R最小_OEI P R最小_OEI It is the minimum total instantaneous power required for the aircraft to continue flying.

[0039] More specifically, P R最小_OEI This is the minimum power required for sustained flight under satisfactory safety conditions; this power depends solely on the characteristics of the aircraft and is independent of whether it is in training mode, normal flight, or a malfunction. For example, on a twin-engine helicopter, this typically corresponds to OEI30 (or SEP, which stands for "super-emergency power"), and on a single-engine helicopter, it is 90% MTOP (maximum take-off power).

[0040] To clearly distinguish between the limitations applied in training mode (i.e., during simulation) and those existing outside of training mode (e.g., under real-world fault conditions), indices "_Ecol" and "_OEI" were added respectively (e.g., during training mode, P...). M2lim and P M2最小 Written as P M2lim_Ecol and P M2最小_EcolAnd when not in training mode, P M2最大 Written as P M2最大_OEI ).

[0041] In addition, it should be noted that P M2最大_OEI and P M2最大 They are exactly the same; both refer to the maximum power that the second power system can provide in actual fault conditions (i.e., when not in training mode).

[0042] Furthermore, it should be noted that, in the context of this invention, the terms "training" or "training mode" are used interchangeably.

[0043] Some preferred, but non-limiting, aspects of this method are as follows:

[0044] Advantageously, the second power system is selected from a hydraulic power system or an electric power system, and the first power system is selected from a gas turbine power system.

[0045] According to a variation of the invention, the second power system is reversible, increasing the instantaneous power P provided by the second power system. M2inst Before proceeding to the next step, the following steps can be performed first: The instantaneous power P provided by the first power system is transferred through the second power system. M1 A portion of the power is drawn into the transmission unit, thereby obtaining the instantaneous total power P provided by the first power system and the second power system during the simulation. tot_Ecol The rate of decline is faster.

[0046] According to a variation, the instantaneous power P provided by the first power system is reduced. M1inst The steps include: reducing the power transient of the first power system to P. M1Ecol Subsequently, the power of the first power system will be increased to P. M1Ecol .

[0047] According to a variation, an increase in the instantaneous power P provided by the second power system is triggered. M2inst The step is delayed and / or the instantaneous power P provided by the second power system is... M2inst The increase is slowed down, resulting in transient power loss.

[0048] According to a variant, the second dynamic system is reversible, and P M1Ecol Selected as higher than or equal to P R最小_Ecol (P R最小_Ecol(This refers to the minimum total instantaneous power required for the aircraft to fly continuously in training mode). During the step of increasing the power provided by the second power system, the second power system performs at least once a step of drawing a portion of the power provided by the first power system to the transmission unit, and the maximum portion P that can be drawn is... M2最小_Ecol It is a negative value, and in absolute value equal to the maximum power that the second power system can draw from the transmission unit in the training mode, where P M1Ecol +P M2最小_Ecol ≤P R最小_Ecol Choose P M1Ecol ≥P R最小_Ecol This ensures that the power of the first dynamic system is maximized during the fault training phase (training) so that, in the event of a real fault affecting one of the (n-1) other dynamic systems during this training phase, the first dynamic system can provide its maximum response to return to its maximum power; in other words, the constraint can be summarized as follows:

[0049] -To meet minimum power requirements:

[0050] P M1Ecol +P M2最小_Ecol =P R最小_Ecol

[0051] Among them, P M2最小_Ecol The maximum power (absolute value) that the second power system can draw upon in training mode (given P) M2最小_Ecol (Can be negative); and

[0052] -To meet maximum power requirements:

[0053] P M1Ecol +P M2lim_Ecol =P M2最大_OEI

[0054] Among them, P M2lim_Ecol The second dynamic system enables P in the training mode. tot_Ecol No more than P M2最大_OEI The maximum power that can be provided.

[0055] According to a variation, the power P of the first power system is adjusted in real time during the simulation. M1Ecol and the power limit P of the second power system M2lim_Ecol This ensures that the average power of the second propulsion system during the simulation is equal to the reference power P selected to ensure a margin for piloting the aircraft. M2réf , where P M2最小 <P M2 réf <P M2lim_Ecol And P M2lim_Ecol (t)+PM1Ecol (t)=P M2最大_OEI .

[0056] Another object of the present invention is an apparatus for training pilots under the influence of a failure in the power system of an aircraft hybrid propulsion system, the hybrid propulsion system comprising n power systems, where n is an integer greater than or equal to 2, the n power systems including a first power system and a second power system that are substantially different and connected in parallel on a transmission unit, the apparatus comprising a control device configured to implement a training method defined according to the present invention.

[0057] The control device may include: an adjustment system that adjusts the corresponding power of the first power system and the second power system, and a control system that controls the corresponding power of the n power systems.

[0058] Finally, the object of the present invention is an aircraft equipped with a hybrid propulsion system and a training device as defined in the present invention, the hybrid propulsion system comprising n power systems, where n is an integer greater than or equal to 2, the n power systems including a first power system and a second power system that are substantially different and connected in parallel on a transmission unit.

[0059] The method according to the invention enables pilots to conduct flight training under degraded conditions simulating a failure of one of the power systems affecting the power system.

[0060] The method according to the invention enables the ingenious distribution of power provided by at least two power systems, such that:

[0061] - During the simulation, the total power supplied to the two power systems will be limited to the maximum power of the power system that is considered to be working properly;

[0062] - Keep the simulated faulty power system in sufficient operating mode to keep it responsive while making it "transparent" to the pilot;

[0063] - Provides behavioral and dynamic changes so that the power supplied to the aircraft corresponds perfectly to the power system that is considered operable;

[0064] - If a failure affecting a supposedly operational power system is detected during training, the training operation is interrupted, and the simulation is restarted very quickly to simulate the faulty power system, enabling it to provide the power required for continued flight under satisfactory and safe conditions. Attached Figure Description

[0065] Other aspects, objects, advantages, and features of the invention will become clear from the following detailed description of preferred embodiments, which is given by way of non-limiting example with reference to the accompanying drawings, in which:

[0066] - Figure 1 The structure and regulation system of an example of a hybrid propulsion system with two parallel power systems according to the present invention are schematically shown.

[0067] - Figure 2 This shows the impact of actual failures. Figure 1 An example of the power curve in the case of a hybrid propulsion system;

[0068] - Figure 3 The simulated fault effects according to the present invention are shown. Figure 1 An example of a power curve in the case of one of the power systems of a hybrid propulsion system;

[0069] - Figure 4 Examples of power loss curves compared to real faults are shown in the case of simulated faults affecting the power system according to two variations of the present invention.

[0070] - Figure 5 An example of a power curve simulating the effect of a fault on the first power system according to a variant 1 of the present invention is shown;

[0071] - Figure 6 An example of a power curve simulating the effect of a fault on the first power system according to a variant 2 of the present invention is shown;

[0072] - Figure 7 According to the present invention, variant 3 Figure 1 Detailed view of the adjustment system 5;

[0073] - Figure 8 An example of a power curve simulating the effect of a fault in the first power system according to a variant 3 of the present invention is shown. Detailed Implementation

[0074] In the context of this invention, a propulsion system is a system for generating and providing hybrid and redundant propulsion power. In other words, because the propulsion system comprises at least two fundamentally different power systems, it is hybrid, and because these at least two power systems are arranged in parallel on the transmission unit, it is redundant. This allows the aircraft to land under satisfactory safety conditions in the event of a partial failure affecting one of the two power systems. The term "partial failure" should be understood here as a failure affecting only one of the power systems in the parallel power system. Since at least one of the redundant power systems is functional, the propulsion system as a whole is partially faulty.

[0075] A typical application example is the parallel hybrid propulsion system of helicopters, which consists of a turboshaft engine and electric motors that drive the main rotor and tail rotor.

[0076] In the illustrative examples below, the invention will be applied to a hybrid propulsion system comprising two parallel independent power systems (so-called dual-engine cases), namely a first power system having a gas turbine-type engine and a second power system having an electric motor.

[0077] Figure 1 The architecture of the hybrid propulsion system and its regulation system 5 is shown.

[0078] exist Figure 1 In the specific application scenario shown, the hybrid propulsion system includes two redundant power systems: a primary power system and an auxiliary power system, referred to as the first power system 1 and the second power system 2, respectively. These two power systems are independent, essentially different, and redundant (or parallel), meaning they transmit mechanical power to the rotor 4 via a transmission unit 3, which adjusts and aggregates the power from both power systems.

[0079] In this embodiment, the primary propulsion system 1 includes a heat engine 10, which may be a gas turbine, and is designed to provide most of the power required for the aircraft's flight. The auxiliary propulsion system 2 includes one or more electric motors (in this case, a single electric motor 20) and allows for the provision of supplemental power, which essentially enables continued flight within a confined area until landing under satisfactory safety conditions. The primary function of the auxiliary propulsion system 2 is to overcome failures affecting the primary propulsion system 1 while minimizing onboard added mass. The maximum power it can provide is less than or equal to the maximum power of the primary propulsion system.

[0080] exist Figure 1 In, N R * is the rotational speed setting for rotor 4 (also known as the propeller); N M1 (N M2 ) is a measurement of the engine speed of the first (second) power system; C M1 (C M2 P is a measured value of the torque transmitted by the engine of the first (second) power system; M1 *(P M2 *) is the power control of the engine in the first (second) power system.

[0081] Data N R *、N M1 N M2 C M1 C M2 The data is transmitted to the control system 5. (Data P)M1 * and P M2 *The heat engine 10 of the first power system 1 and the electric motor 20 of the second power system 2 are supplied respectively. Each engine is connected to the main drive unit 3 via a shaft 6, which transmits the power of one (or more) engines to the rotor. Each shaft is provided with a measuring device 7, which enables the measurement of the speed and torque transmitted by the associated engine.

[0082] Figure 2 This illustrates the time-varying effects provided in the event of an actual engine failure affecting the primary power system. Figure 1 The current total power of the aircraft rotor (curve 3). Curves 1 and 2 represent the instantaneous power provided by the first and second power systems over time, respectively.

[0083] When a fault occurs in the engine affecting the first power system (indicated by a flashing light), the power supplied by the first power system rapidly decreases until it stops completely. To overcome this fault, the power of the second power system increases to its maximum power P. M2最大 , can be represented as P M2最大_OEI To clearly indicate the actual fault situation (when not in training mode).

[0084] Figure 3 The simulated fault conditions affecting engine 10 are shown. For example... Figure 2 As shown, curves 1, 2, and 3 represent the instantaneous power provided by the first power system and the second power system, and the current total power provided to the rotor over time, respectively.

[0085] Initially, starting from the operating point, the current total power is higher than the maximum power of the engine considered to be operating normally during the simulation phase. In this example, the engine includes a second power system, so its maximum power is P. M2最大_OEI In practice, the goal of the training mode is to simulate flight conditions where the total available power is limited by the maximum power P of the second power system. M2最大_OEI Restrictions.

[0086] When the pilot selects training mode and triggers a malfunction affecting engine 10, the regulation system 5 reduces the power supplied by the primary power system as quickly as possible without shutting it down. Therefore, this rapid power reduction simulates the loss of available rotor power when the primary power system fails.

[0087] Therefore, the regulating system decelerates the engine 10 of the first power system at its maximum achievable deceleration rate without shutting off the combustion chamber. Thus, instead of reducing the power of the engine 10 until it comes to a complete stop, the regulating system reduces the power of the engine 10 to an intermediate power level P. M1EcolThen it remains unchanged until the fault training operation ends. In other words, when the training mode is triggered, there is a deceleration transient phase (initial power drop) of engine 10, and then the power level is maintained at a stable power level P. M1Ecol The deceleration transient phase of engine 10 is independent of the subsequently maintained level P. M1Ecol .

[0088] Select the power level P of engine 10. M1Ecol This is the main advantage of the present invention.

[0089] On the one hand, this level P M1Ecol The power level needs to be selected high enough to maintain sufficient acceleration capability for engine 10 so that it can quickly return to its maximum power in the event of a failure in engine 20 during training operations. This allows for a higher safety level during the training phase. Typically, the power level P... M1Ecol The higher the value, the faster the engine 10 can restart when necessary. Therefore, the goal is to set the highest possible power level P. M1Ecol It also meets the maximum power level of the engine (P 20). M2最大_OEI ).

[0090] On the other hand, this level P M1Ecol It is also not advisable to select too high a value, so that the engine 10 does not affect the behavior of the propulsion system as perceived by the pilot.

[0091] As a hint, the constraints can be summarized as follows:

[0092] P M1Ecol +P M2最小_Ecol =P tot_最小_Ecol =P R最小_Ecol To meet minimum power requirements; and

[0093] P M1Ecol +P M2lim_Ecol =P tot_最大_Ecol =P M2最大_OEI To meet the maximum power requirement.

[0094] In this way, the power of engine 10 can remain constant. Therefore, changes in rotor power can be entirely achieved by engine 20. Consequently, the pilot's experience is faithful to that of a pilot powered entirely by engine 20.

[0095] Figure 4 A comparison of power loss curves under simulated and actual faults is shown. Curve 1 represents the curve of an actual fault in engine 10, curve 2 represents the deceleration curve of engine 10 at the so-called "anti-extinction" limit, and curve 3 represents the curve of a simulated fault according to variant 1 of the present invention. Figure 4As shown, depending on the performance of engine 10, the deceleration at the "anti-shutdown" limit (curve 2) of engine 10 may be slower than the power drop observed under some fault conditions (e.g., in cases where engine braking occurs due to loss of lubrication or cutoff of the fuel supply valve).

[0096] Variant 1: Using engine 2 in braking mode during fault transients

[0097] In variant 1, the power decrease is applied during the initial transient phase when entering training mode.

[0098] As mentioned earlier, a potential limitation of simulating engine failure by controlling the controlled deceleration of engine 10 is that the maximum achievable deceleration may be significantly slower than the real power loss associated with a real engine failure.

[0099] If the power system 2 of engine 20 is reversible, that is, engine 20 can draw mechanical power from BTP (whether by braking BTP to charge the battery or by consuming electricity), then by drawing mechanical power from engine 10, engine 20 can be used to make the power supplied to the rotor drop faster.

[0100] like Figure 5 As shown, this variant 1 includes instantaneously controlling the negative power on engine 20 (a portion of the curve represented by circle 4) in order to obtain a decrease in total power that better represents the power curve caused by the actual situation of engine failure.

[0101] It is understandable that, as in the literature describing methods for simulating fault OEI in a dual-engine configuration (see, for example, reference [2]), transient power loss simulation is not mentioned here. In the case of an electric hybrid propulsion system, since engine 20 (electric) provides a much superior responsiveness to the gas turbine, such transient power loss simulation may be unnecessary. Therefore, the inherent responsiveness of the electrical technology allows for very rapid compensation of the power loss of engine 10, and thus eliminates or at least greatly mitigates the transient power loss following a fault. Nevertheless, without limitation, the present invention can also simulate such transient power loss. This can be achieved in three ways, and possibly in combination:

[0102] - The adjustment system can instantly reduce the power of engine 10 to P. M1Ecol Then, return to this level;

[0103] - The regulating system can also delay and / or slow down the power of engine 20, so that the sum of the power of the two engines is temporarily lower than the maximum power that the second power system can provide (using P). M2最大(Indicates) or temporarily below the power P required by the aircraft. R最小_Ecol ;

[0104] -According to Variation 1 proposed above, the negative power level can be transiently controlled on engine 20, causing it to draw power from the BTP. By adjusting the duration of power draw, a transient power loss of varying length can be simulated before returning to maximum power.

[0105] In addition, the responsiveness of engine 10 and the minimum power P required for remaining flight R最小_Ecol A balance between these factors may be difficult to achieve.

[0106] The two variants of the invention described below (hereinafter referred to as variant 2 and variant 3) allow selection of a power P higher than the minimum power required for sustained flight. R最小_Ecol Level P M1Ecol This can facilitate such a trade-off.

[0107] The regulating system 5 keeps the engine 10 at a constant power P. M1Ecol And continuously adjust the power of engine 20 to the required level to keep the rotor speed at the desired speed.

[0108] The regulating system 5 also limits the power of engine 20 to level P. M2lim_Ecol So that the total output power of the two engines does not exceed the engine's maximum power P20. M2最大_OEI Therefore, the limit P M2lim_Ecol The calculation is as follows:

[0109] P M2lim_Ecol =P M2最大_OEI -P M1Ecol

[0110] Therefore, engine 20 operates at an average power level far below its maximum power, without the pilot noticing. This also has the advantage of consuming significantly less electrical energy, which can be advantageous when electrical energy is supplied by batteries (whose available energy is necessarily limited).

[0111] Throughout the training, the engine parameters returned to the pilot's display by the control system were "manipulated" so that they represented what would be displayed under real fault conditions. Thus, the speed, torque, or power of engine 10 was indicated as zero to represent its simulated fault state, even though the engine actually provided a significant power level. Conversely, the equivalent parameters of engine 20 were indicated at the levels it would be at if it were the only engine powering the rotor.

[0112] Throughout the training process, the control system continuously monitors the operation of both engines. Therefore, in the event of an actual fault detected in either engine, the control system immediately interrupts the fault training and simulation program and immediately reactivates the engine unaffected by the fault, thereby providing all the power required for continued flight.

[0113] Variant 2: Engine 2 using braking mode during remaining training flights.

[0114] In variant 2, the average power level provided by engine 1 is applied to the remainder of the training mode.

[0115] As mentioned above, the trade-off between the power required to maintain good responsiveness of engine 1 and the minimum power level required to continue training flights can be very difficult to meet.

[0116] To achieve this trade-off, a variation of the invention uses engine 2 in a reversible manner, thereby increasing the power P of engine 1. M1Ecol The solution can only be implemented by charging a storage component (e.g., a battery) or by momentarily consuming that power (e.g., through an electrical resistor) if engine 2 can draw mechanical power from the BTP and the power system of engine 2 is reversible. According to this variant 2, the regulating system controls the power level P. M1Ecol The power level is higher than that controlled according to the basic invention. In this variant 2, when the engine 10 is simulated to be faulty, the power P provided by the engine 10 is higher than that controlled according to the basic invention. M1Ecol Higher than the minimum power P for flight R最小_Ecol When P R最小_Ecol (t) <P M1Ecol In order to maintain the rotor speed at the desired level, the regulating system controls the negative power of engine 20. Therefore, the total power of the two engines is maintained at the level required by the rotor.

[0117] In this variant 2, constant P M1Ecol The choice of power is always subject to two constraints:

[0118] - In the event of a malfunction affecting engine 20 during training, it should always be as high as possible to improve the responsiveness of engine 10;

[0119] - The engine's minimum power output P must not exceed 20. M2最小 :

[0120] P M1Ecol ≤P R最小_Ecol -P M2最小

[0121] This minimum power P M2最小Here it is negative, and (in absolute value) corresponds to the maximum power that engine 20 can extract from BTP. This minimum power P M2最小 Not necessarily equal to maximum power P M2最大_OEI And it can depend on the ability of the power system of engine 20 to absorb the power regenerated by the engine. In the case of an electric power system, it can be the maximum charging power of the battery, or the maximum power consumed by the "braking resistor". When only one battery is allowed to absorb the power drawn from engine 20, the minimum power P is... M2最小 It may also be limited for energy reasons. In fact, at any point during training flights, the energy regenerated by engine 20 should not exceed the maximum capacity of the battery.

[0122] Variant 3: P M1Ecol Real-time adjustment to eliminate the need for constant P M1Ecol Safety / Representativeness Trade-off

[0123] In variant 3, the average power level provided by engine 1 is applied to the remainder of the training mode.

[0124] As explained above, during training, P M1Ecol It should be as high as possible so that:

[0125] - Ensure flight safety in the event of an actual malfunction affecting engine 20, while also noting:

[0126] The power loss caused by the actual fault affecting engine 20 is always low because engine 20 is operating at low power (and therefore because engine 10 is operating at high power);

[0127] The responsiveness of engine 1 will be as fast as that of engine 10 when running at high power (only in the case of gas turbine);

[0128] - This enables the engine 20 to operate at low power, thereby conserving its energy source (if the energy source is a battery, it is particularly advantageous to be able to repeat training sessions that address malfunctions affecting the engine 10 without charging the battery).

[0129] On the other hand, as has already been explained, P M1Ecol It should be low enough so that engine 20 can compensate for the power reduction required by the rotor, while meeting P M2inst >P M2最小 (Where the power system of engine 20 is irreversible, then P) M2最小 =0, and if the power system of engine 20 is reversible, then P M2最小 <0) to ensure good representativeness of the dynamic behavior of the dynamic system.

[0130] In practice, the aim is to limit P M1Ecol The aforementioned trade-offs may be difficult (or even impossible) to find.

[0131] In variant 3, it is recommended to adjust mechanism P in real time over time. M1Ecol So that the engine 20 is around just the necessary power (piloting margin) P M2_réf(t) Operation is performed to ensure good representativeness of the dynamic behavior of the power system. M1Ecol An example of real-time adjustment is shown in the following figure ( Figure 7 and Figure 8 As shown in the figure.

[0132] exist Figure 7 In the previous section, a specific embodiment of variant 3 has been described in detail in the regulation system.

[0133] Power P M1Ecol The "slow" nature of real-time adjustments allows engine 20 (faster) to perfectly compensate for the extra power supplied to the rotor, making the power changes of engine 10 transparent to the pilot.

[0134] It goes without saying that, in the case of Variant 3, it is also necessary to adjust the engine's power limit P in real time. M2lim_Ecol This ensures that the total power supplied by the two engines will never exceed the maximum power of engine 20.

[0135] P M2lim_Ecol (t)=P M2最大_OEI -P M1Ecol (t)

[0136] In order to adjust the gas turbine (turboshaft engine) mechanism P in real time M1Ecol This adjustment can be made based on one or more of the following factors:

[0137] - Control of the aircraft's collective pitch;

[0138] -Power prediction information from aircraft;

[0139] -The average power provided by engine 20 over a given time period;

[0140] - Any other information that can be used to estimate the average power demand level of the rotor.

[0141] For example, it could be:

[0142] P M1Ecol (t) = low-pass filter (P) Helico (t)–P M2 réf )

[0143] Among them, P M2 réf These are constant values, where the helicopter's real-time power (P) Helico (t) is, for example, equal to:

[0144] P M1inst (t)+P M2inst (t), where P M1inst (t) is the power provided in real time by the first power system, and P M2inst (t) is the power provided in real time by the second power system; or

[0145] - Estimated power for total pitch type; or

[0146] - Estimated power of avionics equipment; etc.

[0147] Therefore, the average can be obtained as follows:

[0148] P M1Ecol (t)=P M1inst (t)

[0149] P M2inst (t)=P M2 réf P M2 réf The desired driving margin.

[0150] It should be noted that the dynamics of the low-pass filter should be slower than the possible dynamics of the first dynamic system.

[0151] The illustrative example above is based on a dual-engine hybrid propulsion system. Nevertheless, the invention can cover any multi-engine application where pilot training includes simulating a failure affecting one of the several engines. For example, a configuration with three engines in parallel, one or two of which are electric, is conceivable.

[0152] Furthermore, the illustrative examples described above depict training pilots to handle failures affecting an engine that no longer provides power (a total engine failure), as this typically places the highest demands on piloting and imposes the greatest limitations on the simulation. Nevertheless, the present invention can cover all cases of partial engine failures, where the engine continues to provide a given power level, but with some degree of performance degradation. For example, a complete failure affecting power regulation, the so-called "freeze," is conceivable, where the simulated faulty engine is frozen at a constant power level at a point in the flight domain.

[0153] References cited

[0154] [1]US 6,917,908 B2

[0155] [2]US 8,025,503 B2

[0156] [3]EP 2 724 939 B1

[0157] [4]EP 2 886 456 A1

Claims

1. A method for training pilots to handle malfunctions affecting the power systems of a hybrid propulsion system of an aircraft, the hybrid propulsion system comprising n power systems connected in parallel on a transmission unit, where n is an integer greater than or equal to 2, the n power systems including a first power system and a second power system that are substantially different, the method comprising, during flight of the aircraft, simulating malfunctions affecting the first power system by performing the following steps: - The instantaneous power P provided by the first power system M1inst Reduced to training power P M1Ecol And maintain the power P M1Ecol Until the simulation ends, where: P M2最大_OEI >P M1Ecol >P M1最小 P M2最大_OEI The instantaneous maximum power that the second power system can provide when not in training mode, and P M1最小 The instantaneous minimum power that the first power system can provide; as well as - The instantaneous power P provided by the second power system M2inst Increase to below or equal to the upper limit power P applicable to the second power system in the training mode. M2lim_Ecol The power, and the adjustment of the power P during the simulation. M2inst This ensures that the instantaneous total power P provided by the first power system and the second power system in the training mode... tot_Ecol Less than or equal to P M2最大_OEI ,in: P tot_Ecol =P M1Ecol +P M2inst P tot_Ecol ≤ P M2最大_OEI P M2inst ≤ P M2lim_Ecol <P M2最大_OEI P M2lim_Ecol + P M1Ecol = P M2最大_OEI P M2lim_Ecol The second dynamic system in the training mode makes P tot_Ecol No more than P M2最大_OEI The maximum power that can be provided; The method further includes: while performing the simulation, checking the status of the n power systems of the propulsion system; and if a fault affecting one of the n power systems is detected, stopping the simulation and increasing the instantaneous power provided by at least one of the first power system and the second power system, such that the sum of the instantaneous power provided by the n power systems is greater than or equal to P. R最小_OEI P R最小_OEI It is the minimum total instantaneous power required for the aircraft to continue flying.

2. The method according to claim 1, wherein, The second power system is selected from a hydraulic power system or an electric power system, and the first power system is selected from a gas turbine power system.

3. The method according to claim 1, wherein, The second power system is reversible, increasing the instantaneous power P provided by the second power system. M2inst Before proceeding to the first step, the following steps are performed: the instantaneous power P provided by the first power system is transferred through the second power system. M1 A portion of the power is drawn into the transmission unit, thereby obtaining the instantaneous total power P provided by the first power system and the second power system during the simulation. tot_Ecol The rate of decline is faster.

4. The method according to claim 2, wherein, The second power system is reversible, increasing the instantaneous power P provided by the second power system. M2inst Before proceeding to the first step, the following steps are performed: the instantaneous power P provided by the first power system is transferred through the second power system. M1 A portion of the power is drawn into the transmission unit, thereby obtaining the instantaneous total power P provided by the first power system and the second power system during the simulation. tot_Ecol The rate of decline is faster.

5. The method according to any one of claims 1 to 4, wherein, Reduce the instantaneous power P provided by the first power system M1inst The steps include: reducing the power transient of the first power system to P. M1Ecol Subsequently, the power of the first power system will be increased to P. M1Ecol .

6. The method according to any one of claims 1 to 4, wherein, The instantaneous power P provided by the second power system is increased. M2inst The triggering of the step is delayed and / or the instantaneous power P provided by the second power system is delayed. M2inst The increase is slowed down, resulting in transient power loss.

7. The method according to any one of claims 1 to 4, wherein, The second power system is reversible, and P M1Ecol Selected as higher than or equal to P R最小_Ecol (P) R最小_Ecol (This refers to the minimum total instantaneous power required for the aircraft to fly continuously in training mode). During the step of increasing the power provided by the second power system, the second power system performs at least once a step of drawing a portion of the power provided by the first power system to the transmission unit, and the maximum portion P that can be drawn is... M2最小_Ecol It is a negative value, and in absolute value equal to the maximum power that the second power system can draw from the transmission unit in the training mode, where P M1Ecol +P M2最小_Ecol ≤P R最小_Ecol .

8. The method according to claim 7, wherein, The power P of the first power system is adjusted in real time during the simulation. M1Ecol and the power limit P of the second power system M2lim_Ecol This ensures that the average power of the second propulsion system during the simulation is equal to the reference power P selected to ensure a margin for piloting the aircraft. M2 réf , where P M2最小 <P M2 réf <P M2lim_Ecol And P M2lim_Ecol (t) + P M1Ecol (t) = P M2最大_OEI .

9. An apparatus for training pilots to handle malfunctions of a power system affecting a hybrid propulsion system of an aircraft, the hybrid propulsion system comprising n power systems, where n is an integer greater than or equal to 2, the n power systems including a first power system and a second power system that are substantially different and connected in parallel on a transmission unit, the apparatus comprising a control device configured to implement the method for training pilots to handle malfunctions of a power system affecting a hybrid propulsion system of an aircraft according to any one of claims 1 to 8.

10. An aircraft equipped with a hybrid propulsion system and, according to claim 9, means for training a pilot to handle malfunctions of the power system affecting the hybrid propulsion system of the aircraft, the hybrid propulsion system comprising n power systems, where n is an integer greater than or equal to 2, the n power systems including a first power system and a second power system that are substantially different and connected in parallel on a transmission unit.

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