Method and unit for controlling an entire motor

Abstract

Method and Control Unit for a Motor Assembly. The present invention relates to a method for controlling a motor assembly (100). This motor assembly (100) comprises at least one first electric machine (300) and a gas turbine engine (200). The gas turbine engine (200) comprises a low-pressure shaft (210) and a high-pressure shaft (220). The electric machine (300) is coupled to the low-pressure shaft (210), and the control method includes a step in which mechanical work is taken from the first electric machine (300) to brake a rotation of the low-pressure shaft (210) in response to an activation of a thrust reverser (281) of the gas turbine engine (200) and / or to a disturbance of the airflow in a transverse plane at an air intake of the gas turbine engine (200).The invention also relates to a control unit (500) adapted to perform this process, a motor assembly (100) incorporating this control unit (100), the electric machine (300) and the gas turbine motor (200), and a computer program to perform this process. Figure for the abstract: Fig. 1.

Description

Title of the invention: Method and unit for controlling an assembly of motors technical field

[0001] The present invention relates to the technical field of aircraft engine assemblies, and more particularly to engine assemblies comprising at least one electric machine and one gas turbine engine with at least one high-pressure shaft and one low-pressure shaft. Previous technique

[0002] In order to increase the overall energy efficiency of means of transport and reduce their fuel consumption and greenhouse gas emissions, numerous hybrid powertrains have already been proposed, combining combustion engines and electric machines that contribute to overall efficiency beyond simply starting internal combustion engines. Although these hybrid powertrains have most often been proposed for motor vehicles and have incorporated piston engines, the hybridization of gas turbine engines, and more specifically of gas turbine engines for aircraft, has also been considered.

[0003] In the context of gas turbine engines, and in particular aircraft gas turbine engines, hybridization can in fact offer advantages other than energy efficiency. For example, in French patent application FR 3 094 043 A1, it was proposed to use an electric machine to extract mechanical work from the low-pressure shaft of a gas turbine engine and thus brake it, in order to avoid instability in the low-pressure compressor, and in particular the risk of surge, which could be exacerbated, for example, during deceleration of the gas turbine engine and / or changes in the stator blade pitch angle. This can avoid the need to open relief valves at the outlet of the low-pressure compressor, and thus prevent a loss of energy efficiency. Description of the invention

[0004] The inventors have recognized other situations presenting a risk of instability in the low-pressure compressor of a gas turbine engine with a high-pressure shaft and a low-pressure shaft. The present disclosure therefore aims to prevent, in these other risky situations, instability of the low-pressure compressor of such a gas turbine engine in an aircraft engine assembly comprising the gas turbine engine and at least one first electrical machine to which the low-pressure shaft of the gas turbine engine is mechanically coupled, without having to open any valves. dump.

[0005] For this purpose, according to a first aspect of this disclosure, a method for controlling such a motor assembly may include a step in which a mechanical work take-off is commanded to the first electric machine to brake a rotation of the low-pressure shaft in response to an activation of a thrust reverser of the gas turbine engine and / or to a perturbation of the airflow in a transverse plane at the level of an air intake of the gas turbine engine.

[0006] Thanks to this extraction of mechanical energy, the stability margin of the low-pressure compressor can be effectively extended in response to these risky situations, despite the typically high inertia of the low-pressure shaft, more quickly than with relief valves and by recovering electrical energy that can be used or stored on board the aircraft.

[0007] Thus, the gas turbine engine may include a fan coupled to the low-pressure shaft to be driven in rotation by the low-pressure shaft. In this case, the fan could include variable-pitch blades, and the mechanical work taken up by the first electric machine could be controlled in conjunction with a change in the fan blade pitch, so as to also increase the work absorbed by the fan to better brake the low-pressure shaft.However, the application of this process is also conceivable with other types of gas turbine engines in which the low-pressure shaft would be mechanically coupled in rotation to components with high rotating inertia, such as, for example, a turboprop in which the low-pressure shaft would be mechanically coupled in rotation to at least one pusher propeller, or a turboshaft engine in which the low-pressure shaft would be mechanically coupled in rotation to at least one lift rotor.

[0008] This method is also applicable to engine assemblies comprising a reducer connected to the low-pressure shaft for driving a mechanical component by the low-pressure shaft through the reducer, such as, for example, geared fan turbojets as well as most turboprops and turbomotors.

[0009] This mechanical work can, in particular, be controlled in open loop. Thus, in its simplest form, the extraction of a predetermined mechanical power can be controlled for a similarly predetermined duration in order to extract the mechanical work. However, it is also possible for the mechanical power extracted and / or the duration of the extraction to be variable, depending, for example, on the position of the thrust reverser and / or a component of the airflow in a plane transverse to the air intake.

[0010] A second aspect of this disclosure relates to a control unit for the aforementioned motor assembly which can be adapted to control, in the first electric machine, a mechanical work input to brake a rotation of the low-pressure shaft in response to activation of a thrust reverser of the gas turbine engine and / or to crossflow at an air intake of the gas turbine engine.

[0011] A third aspect of this disclosure relates to a motor assembly comprising the control unit of the second aspect as well as the electric machine and the gas turbine motor.

[0012] A fourth aspect of this disclosure relates to a computer program that may include instructions which, when implemented by a control unit of the aforementioned motor assembly, cause the control unit to perform the control process of the first aspect. Brief description of the drawings

[0013] The purpose of this presentation and its advantages will be better understood upon reading the detailed description below of embodiments given by way of non-limiting examples. This description refers to the attached figure pages, on which:

[0014] [Fig-1] Fig. 1 is a schematic representation of a motor assembly following an embodiment, comprising a gas turbine engine, two electric machines and a control unit.

[0015] [Fig.2] Fig.2 is a representation of an aircraft electrical network comprising two engine assemblies like that of [Fig.1]. Description of the implementation methods

[0016] As illustrated in [Fig.1], a hybrid motor assembly 100 according to one embodiment may include a gas turbine motor 200, a first electric machine 300, a second electric machine 400 and a control unit 500. The gas turbine motor 200 may include a low-pressure shaft 210 and a high-pressure shaft 220. The low-pressure shaft 210 and the high-pressure shaft 220 may be arranged coaxially, as illustrated.The gas turbine engine 200 may also include a low-pressure compressor 230, a high-pressure compressor 240, a combustion chamber 250, a high-pressure turbine 260, and a low-pressure turbine 270, arranged successively in the direction of flow in an annular working fluid channel, so that air admitted upstream of the low-pressure compressor 230 is successively compressed in the low-pressure compressor 230 and in the high-pressure compressor 240, thereby generating hot combustion gases in the combustion chamber 250 by burning fuel injected into this combustion chamber. These combustion gases can then be successively expanded in the high-pressure turbine 260 and in the low-pressure turbine 270, so as to drive them into rotation. The high-pressure shaft 220. can be mechanically coupled to the high-pressure turbine 260 and the high-pressure compressor 240, so that the high-pressure turbine 260 can drive the high-pressure shaft 220 and the high-pressure compressor 240 in rotation, while the low-pressure shaft 210 can be mechanically coupled to the low-pressure turbine 270 and the low-pressure compressor 230, so that the low-pressure turbine 270 can drive the low-pressure shaft 210 and the low-pressure compressor 230 in rotation.

[0017] As in the illustrated embodiment, the gas turbine engine 200 can be a turbofan engine also comprising a fan 280, which can also be mechanically coupled to the low-pressure shaft 230, so that it can also be driven in rotation by the low-pressure turbine 270 through the low-pressure shaft 210. As illustrated, the gas turbine engine 200 could also include a reduction gear 290 interposed between the low-pressure shaft 210 and the fan 280, so that the fan 280 can be driven at a lower rotational speed than the low-pressure shaft 210. However, a fan directly driven by the low-pressure shaft 210 is also conceivable. Furthermore, other architectures of the gas turbine engine 200, without a fan, are also conceivable.Thus, the gas turbine engine 200 could alternatively be a turboprop, with at least one pusher propeller mechanically coupled to the low-pressure shaft 210 through the reduction gear 290, or a turboshaft engine, with at least one lift rotor mechanically coupled to the low-pressure shaft 210 through the reduction gear 290. It is also conceivable, particularly for a turboshaft engine or a turboprop, that the gas turbine engine 200 comprises only a single compressor, mechanically coupled to the high-pressure shaft 210.

[0018] The gas turbine engine 200 may further include a thrust reverser 281, comprising valves and actuators for redirecting forward at least a portion of the air driven by the fan 280, and one or more sensors 282 for detecting a disturbance of the airflow in a transverse plane at the level of the air intake in the gas turbine engine 200, a disturbance which, in a gas turbine engine 200 used to propel an aircraft, may be caused by a crosswind and / or by a vortex flow induced by the aircraft itself.These sensors 282 can be arranged, as illustrated, at the inlet of the gas turbine engine 200, i.e., directly upstream of the fan 280, but it would also be conceivable, alternatively or in addition to this arrangement of the sensors 282, to use sensors arranged elsewhere outside the gas turbine engine 200, in particular to detect crosswinds, and / or sensors arranged inside the gas turbine engine 200 and adapted to detect an instability resulting from a disturbance of the flow at the inlet. These 282 sensors can notably be dynamic pressure sensors.

[0019] The first electric machine 300 can be configured, as illustrated, as a motor-generator to selectively convert electrical energy into mechanical work in motor mode and mechanical work into electrical energy in generator mode. This first electric machine 300 can be mechanically coupled to the low-pressure shaft 210 to drive the low-pressure shaft 210 in motor mode, and to be driven by the low-pressure shaft 210 in generator mode. However, it is also conceivable, within the scope of this disclosure, that it be configured solely as an electric generator, capable only of converting mechanical work into electrical energy.

[0020] Similarly, the second electric machine 400 can also be configured, as illustrated, as a motor-generator to selectively convert electrical energy into mechanical work in motor mode and mechanical work into electrical energy in generator mode. This second electric machine can be mechanically coupled to the high-pressure shaft 220 to drive the high-pressure shaft 220 in motor mode, and to be driven by the high-pressure shaft 220 in generator mode. However, it is also conceivable, within the scope of this disclosure, that it be configured solely as an electric motor, capable only of converting electrical energy into mechanical work.

[0021] As illustrated in [Fig. 2], in an aircraft 10, which may be an aircraft 10 with one or more similar engine sets 100, each of the first and second electric machines 300, 400 of each engine set 100 can be electrically connected to an electrical network 20. This electrical network 20 may be a direct current electrical network, and each of the first and second electric machines 300, 400 of each engine set 100 can then be electrically connected to the electrical network 20 through a corresponding converter 30. To power this electrical network, the aircraft 10 may also include a fuel cell 50, an electrical storage device 60 (which may include, e.g.a battery and / or a supercapacitor) and / or an auxiliary generator set 40, which may include a generator 41 mechanically coupled to a combustion engine 42 for its operation and be electrically connected to the electrical network 20 through another converter 30. .

[0022] The control unit 500 may be an electronic control unit, possibly a full authority digital engine control unit (FADEC). In particular, it may take the form of an electronic processor capable of implementing the instructions of a computer program to control the operation of the engine assembly 100. This control unit 500 may be connected to the gas turbine engine 200. Specifically, it is used to receive data from sensors 282 and / or to control the fuel supply to the combustion chamber 250, the position of the thrust reverser valves 281, and / or the setting of the various adjustable vanes, as well as to each of the first and second electric machines 300 and 400 to control the injection and / or extraction of mechanical work from the low-pressure shaft 210 and the high-pressure shaft 220, respectively. The control unit 500 can also be connected to a manual control, such as a throttle lever 80, and / or to a flight computer 90, in order to receive an operating command from the engine assembly 100, which may, for example, take the form of a thrust, power, or rotational speed command for the low-pressure shaft 210 and / or the high-pressure shaft 220.In aircraft 10, the control unit 500 of each engine assembly 100 can also be connected to a control unit 70 of the electrical network 20, which can in turn be connected to each converter 30, the generator set 40, the fuel cell 50 and / or the electrical storage device 60, in order to maintain a balance in the electrical network 20.

[0023] The control unit 500 can be adapted to implement a method for controlling the engine assembly 100, in which, in response to the activation of the thrust reverser 281 and / or a crossflow detected through the sensors 282 at the air intake of the gas turbine engine 200, the first electric machine 300 is commanded to draw mechanical work Wei to brake the rotation of the low-pressure shaft 210. The mechanical work Wei supplied by the first electric machine 300 can be controlled in open loop. In this case, both the power drawn by the first electric machine 300 during this supply and the duration of this supply can be predetermined or variable depending, for example, on a position setpoint of the thrust reverser and / or a crossflow component of the air at the intake of the gas turbine engine 200.The power extracted can be constant during the duration of the intake or follow a predetermined profile.

[0024] In order to ensure the electrical supply of the first electric machine 300 during the input while maintaining the balance of the electrical network 20, the control unit 500 can command, simultaneously with the extraction of mechanical work Wei by the first electric machine 300 on the low pressure shaft 210, the injection of a corresponding electrical energy by the second electric machine 400 in the high pressure shaft 220 and / or its storage in the electrical storage device 60.

[0025] Although the present invention has been described with reference to specific embodiments, it is evident that modifications and changes can be made to these examples without departing from the general scope of the invention as such defined by the claims. In particular, individual features of the various embodiments illustrated / mentioned can be combined in additional embodiments. Therefore, the description and drawings should be considered in an illustrative rather than restrictive sense.

Claims

Demands

1. A method for controlling an aircraft engine assembly (100) comprising at least a first electric machine (300) and a gas turbine engine (200) with a high-pressure shaft (220) and a low-pressure shaft (210) mechanically coupled to the first electric machine (300), the control method being characterized in that it includes a step in which a mechanical work withdrawal is commanded to the first electric machine (300) to brake a rotation of the low-pressure shaft (210) in response to an activation of a thrust reverser (281) of the gas turbine engine (200) and / or to a disturbance of the airflow in a transverse plane at an air intake of the gas turbine engine (200).

2. A control method according to claim 1, wherein the gas turbine engine (200) is a turbojet comprising a fan (280) coupled to the low-pressure shaft (210) to be driven into rotation by the low-pressure shaft (210).

3. A control method according to claim 2, wherein the blower (280) comprises variable pitch blades and the mechanical work removal by the first electric machine (300) is controlled jointly with a change in the pitch of the blower blades (280).

4. A control method according to any one of claims 1 to 3, further comprising a reducer (290) connected to the low-pressure shaft (210) for driving a mechanical element by the low-pressure shaft (210) through the reducer (290).

5. A control method according to any one of claims 1 to 4, wherein said mechanical work extraction is controlled in an open loop.

6. A control method according to any one of claims 1 to 5, comprising an additional step of consuming and / or storing electrical energy generated by said mechanical work extraction.

7. Control unit (500) of an aircraft engine assembly (100) comprising at least a first electric machine (300) and a gas turbine engine (200) with a high-pressure shaft (220) and a low-pressure shaft (210) mechanically coupled to the first electric machine (300), the control unit (500) being characterized in that that it is adapted to control, at the first electric machine (300), a mechanical work withdrawal to brake a rotation of the low pressure shaft (210) in response to an activation of a thrust reverser (281) of the gas turbine engine (200) and / or to a disturbance of the airflow in a transverse plane at the level of an air intake of the gas turbine engine (200).

8. Aircraft engine assembly (100) comprising the control unit (500) of claim 7 as well as the first electric machine (300) and the gas turbine engine (200).

9. A computer program comprising instructions which, when implemented by a control unit (500) of an aircraft engine assembly (100) comprising a first electric machine (300) and a gas turbine engine (200) with a high-pressure shaft (220) and a low-pressure shaft (210) mechanically coupled to the first electric machine (300), cause the control unit (500) to perform the control method according to any one of claims 1 to 6.

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