Method and module for detecting status of coupling device, and associated turbomachine and

Abstract

The method for controlling the operation of a coupling device (18) for a turbomachine (4) of an aircraft (2) comprises the following steps:-a first comparison (48) of a determined rotational speed of an electric machine (16) with a curve of evolution with respect to time, the first comparison (48) being carried out in order to determine an operating deviation; -a second comparison (50) of the operating deviation with a detection threshold value; and-identifying the presence or absence of a fault (52) of the coupling device (18) on the basis of the result of the second comparison step (50); the second comparison step (50) comprises determining the value of the detection threshold value as a function of at least one control parameter (P), the operating deviation and the rotational speed of the electric machine (16).

Description

Technical Field

[0001] The present invention relates to detecting the operating state of a coupling device that connects two shafts together.

[0002] More specifically, the present invention relates to a module for controlling the operation of a coupling device, a turbine including the coupling device and such a module, an aircraft including such a turbine, and a method for controlling the operation of the coupling device. Background Art

[0003] An aircraft is generally provided with a turbine that includes at least one rotating shaft, at least one gas turbine, at least one compressor, and a combustion chamber.

[0004] The turbine may include an electric machine, for example, an electric machine with permanent magnets.

[0005] As long as the rotor of the electric machine rotates, the magnets generate an electromotive force.

[0006] During a short circuit, the current generated by the electromotive force causes the circuit through which the current flows to heat up, which is likely to cause a fire on the aircraft.

[0007] It is known to add a coupling device that connects the rotor shaft of the electric machine to the drive shaft of the turbine to separate the drive shaft from the rotor shaft of the electric machine.

[0008] To ensure a high level of availability and operating reliability of the coupling device, it is necessary to regularly control the operation of the coupling device to ensure that when a disconnection instruction is issued, the coupling device separates the drive shaft and the rotor shaft. In particular, during a disconnection instruction after detecting an electric machine failure, it is necessary to confirm the disconnection of the coupling device. Therefore, there is a need for an adaptive method for checking the operating state of the coupling device. Summary of the Invention

[0009] The present invention aims to overcome all or some of these drawbacks.

[0010] The present invention relates to a method for controlling the operation of a coupling device for an aircraft turbine, the turbine including a rotating shaft and an electric machine, the coupling device being configured to connect the rotor shaft of the electric machine to the rotating shaft and having two operating states: a coupling state for fixing the rotor shaft and the rotating shaft; and a separation state for separating the rotor shaft and the rotating shaft, the method including the following steps:

[0011] - Determining the control state of the coupling device;

[0012] - Determining the rotational speed of the electric machine;

[0013] - Determining the rotational speed of the rotating shaft;

[0014] - Compare the determined rotational speed of the electric machine with the time evolution curve of the rotational speed of the electric machine determined based on the rotational speed of the rotary shaft and the control state of the coupling device, and perform this first comparison to determine an operating deviation;

[0015] - Perform a second comparison of the operating deviation with a detection threshold; and

[0016] - Based on the result of this second comparison step, identify whether there is a fault in the coupling device or not;

[0017] This second comparison step includes determining the value of the detection threshold based on at least one control parameter, the operating deviation, and the rotational speed of the electric machine.

[0018] By determining the value of the detection threshold based on the control parameter, the operating deviation, and the rotational speed of the electric machine, the operating state of the turbine can be considered to improve the detection of faults in the coupling device.

[0019] Advantageously, the control parameter is selected from the external temperature, the altitude of the aircraft, and a parameter indicating the type of fault of the electric machine.

[0020] Optionally, this first comparison step includes a previous step of determining the time evolution curve graph of the rotational speed of the electric machine based on the rotational speed of the rotary shaft and the control state of the coupling device.

[0021] Advantageously, this second comparison step includes steps of calculating the gradient of the operating deviation and calculating the gradient of the time evolution curve before this second comparison step, and determining the value of the detection threshold based on the control parameter, the gradient of the operating deviation, and the gradient of the determined rotational speed of the electric machine.

[0022] Advantageously, the method includes a step of delaying the result of this second comparison step.

[0023] Optionally, the method includes controlling the electric machine to be in the motor mode when the turbine is stopped before the step of determining the rotational speed of the electric machine.

[0024] Optionally, the method includes preventing the rotation of the rotary shaft when the electric machine is operating in the motor mode.

[0025] The present invention also relates to a module for controlling the operation of a coupling device for an aircraft turbine, the turbine including a rotary shaft and an electric machine, the coupling device being configured to connect the rotor shaft of the electric machine to the rotary shaft and having two operating states: a coupling state for fixing the rotor shaft and the rotary shaft; and a separation state for separating the rotor shaft and the rotary shaft, the module including:

[0026] - A first determination device configured to determine the control state of the coupling device;

[0027] - A second determination device configured to determine the rotational speed of the electric machine.

[0028] - A third determination device configured to determine the rotational speed of the rotating shaft.

[0029] - A first comparison device configured to compare the rotational speed of the electric machine with a time evolution curve of the rotational speed of the electric machine determined based on the rotational speed of the rotating shaft and the control state of the coupling device, and the first comparison device is configured to determine an operating deviation.

[0030] - A second comparison device configured to compare the operating deviation with a detection threshold; and

[0031] - A device for determining a fault, configured to identify whether there is a fault or no fault in the coupling device based on the result transmitted by the second comparison device.

[0032] The second comparison device is further configured to determine the value of the detection threshold based on at least one control parameter, the operating deviation, and the rotational speed of the electric machine.

[0033] The present invention also relates to an aircraft turbine, which includes a rotating shaft, an electric machine, and a coupling device. The coupling device is configured to connect the rotor shaft of the electric machine to the rotating shaft and has two operating states: a coupling state for fixing the rotor shaft and the rotating shaft; and a separation state for separating the rotor shaft and the rotating shaft. The aircraft turbine includes a control module as defined above.

[0034] Finally, the present invention relates to an aircraft that includes a turbine as defined above. Description of the Drawings

[0035] Other objects, features, and advantages of the present invention will become apparent by reading the following description provided only as a non - limiting example and referring to the drawings, in which:

[0036] Figure 1 schematically shows an aircraft according to the present invention;

[0037] Figure 2 schematically shows a control module according to the present invention; and

[0038] Figure 3 schematically shows a method for controlling the operation of a coupling device of an aircraft turbine according to the present invention. Detailed Description of the Embodiments

[0039] Figure 1 ​​​Schematically shows an aircraft 2 including a turbine 4, which aircraft 2 is, for example, an airplane, a helicopter or a vertical takeoff and landing aircraft.

[0040] The turbine 4 includes at least one rotating shaft (here the rotating shaft 6), on which a fan 8, a compressor 10, a combustion chamber 12 and a turbine 14 are mounted.

[0041] The turbine 4 includes an electric machine 16 and a coupling device 18 that connects the rotor shaft of the electric machine 16 to the rotating shaft 6, for example via a gearbox with a predetermined transmission ratio to the rotating shaft. However, the coupling device 18 can directly connect the rotor shaft of the electric machine 16 to the rotating shaft 6.

[0042] For example, the electric machine 16 includes a permanent magnet synchronous machine or an electromagnetic machine associated with a power electronic converter. The electric machine 16 includes a rotor shaft (not shown).

[0043] Alternatively, the electric machine 16 has a wound rotor.

[0044] The coupling device 18 includes two operating states, namely the so-called 'coupled' state in which the rotor shaft is connected to the rotating shaft 6, and the so-called 'disconnected' state in which the rotor shaft is disconnected from the rotating shaft 6.

[0045] The turbine 4 also includes a control device 20 that can control the coupling device 18 such that the coupling device 18 is in the coupled state or the disconnected state.

[0046] The electric machine 16 includes a diagnostic sensor 22. For example, the diagnostic sensor 22 can be a temperature sensor capable of detecting overheating of the electric machine 16, a force sensor capable of detecting bearing failure of the electric machine 16, an electrical sensor capable of detecting a short circuit of the electric machine 16, a pressure sensor or an oil level sensor.

[0047] Alternatively, the diagnostic sensor 22 can be regarded as a set of different sensors selected from, for example, temperature sensors, force sensors, pressure sensors, oil level sensors and electrical sensors.

[0048] In addition, the turbine 4 includes a temperature sensor 24 capable of measuring the temperature outside the turbine 4 and an altitude sensor 26 capable of measuring the altitude at which the turbine 4 is located.

[0049] The coupling device 18 is controlled by a control module 28.

[0050] As Figure 2 shown, the control module 28 includes: a first device 30 for determining the control state of the coupling device 18; a second determination device 32 capable of determining the rotational speed of the electric machine 16; a third determination device 34 capable of determining the rotational speed of the rotating shaft 6.

[0051] The first determination device 30 is electrically connected to the control device 20, for example.

[0052] The second determination device 32 includes, for example, a rotational speed sensor capable of measuring the rotational speed of the rotor shaft of the electric motor 16.

[0053] The third determination device 34 includes, for example, a rotational speed sensor capable of measuring the rotational speed of the rotating shaft 6.

[0054] The control module 28 further includes a first comparison device 36 configured to compare the rotational speed of the electric motor 16 with the time evolution curve of the rotational speed of the electric motor 16 determined based on the rotational speed of the rotating shaft 6 and the control state of the coupling device 18. Thus, the first comparison device 36 is configured to determine an operating deviation.

[0055] These first comparison devices 36 may include a software architecture designed to implement a comparison algorithm. Such a first comparison device 36 may be in the form of, for example, a logic circuit forming a comparator.

[0056] The second comparison device 38 (for example, in the form of a comparator or a software architecture integrating a second comparison algorithm) ensures a comparison between the operating deviation and a detection threshold.

[0057] The second comparison device 38 determines the value of the detection threshold based on at least one control parameter P, the operating deviation, and the rotational speed of the electric motor 16.

[0058] The control module 28 includes a device 40 for determining a fault (for example, a software device) configured to identify the presence or absence of a fault in the coupling device based on the result transmitted by the second comparison device 38. This device for determining a fault is electronically connected to the indicator light or alarm system (possibly audible) of the aircraft 2 to warn the operator of the fault. Optionally, the device 40 for determining a fault is capable of stopping the turbine 4 in the event of a fault in the state change of the coupling device 18, and when the turbine 4 stops, the electric motor 16 no longer rotates.

[0059] Figure 3 A method for controlling the operation of the coupling device 18 is schematically shown.

[0060] It is assumed that the combustion chamber 12 generates hot gas to drive the turbine 14.

[0061] During step 42 of determining the control state of the coupling device 18, the first determination device 30 and the control device 20 determine the control state of the coupling device 18. The control state of the coupling device 18 is transmitted in the form of a control command in the coupled state or the separated state of the coupling device 18.

[0062] During step 44 of determining the rotational speed of the electric machine 16, the rotational speed sensor of the second determination device 32 measures the rotational speed of the rotor shaft of the electric machine 16. The rotational speed of the electric machine 16 is stored, for example, in the memory of the second determination device 32.

[0063] In the next step 46, the rotational speed of the rotating shaft 6 is determined. The rotational speed sensor of the third determination device 34 measures the rotational speed of the rotating shaft 6. For example, the measured rotational speed of the rotating shaft 6 is stored in the memory of the third determination device 34.

[0064] Steps 42, 44 and 46 can be performed simultaneously or successively.

[0065] Thus, the first comparison device 36 compares the rotational speed of the electric machine 16 with the time evolution curve of the rotational speed of the electric machine 16 determined based on the rotational speed of the rotating shaft 6 and the control state of the coupling device 18 to determine the operating deviation (step 48).

[0066] For example, the operating deviation is equal to the difference between the rotational speed of the electric machine 16 and the time evolution curve. This difference can be an instantaneous difference or the sum of the differences between the rotational speed of the electric machine 16 and the time evolution curve determined over a predetermined time.

[0067] The time evolution curve includes the change in the rotational speed of the rotating shaft 6 when the coupling device 18 is in the coupled state, or includes the change in the rotational speed of the rotating shaft 6 when the coupling device 18 is in the separated state. For example, this time evolution curve can be obtained from a reliable operating model of the coupling device 18 or, for example, from the data sheet of the electric machine 16.

[0068] This time evolution curve is extracted from a time evolution curve chart of the rotational speed of the electric machine 16.

[0069] This chart is determined based on the rotational speed of the rotating shaft 6 and the control state of the coupling device 18 before the first comparison step.

[0070] This time evolution curve chart enables the rapid determination of the time evolution curve used during the first comparison step 48.

[0071] In the next step 50, the second comparison device 38 compares the operating deviation with a detection threshold.

[0072] The detection threshold is variable and is determined based on the control parameter P, the operating deviation and the rotational speed of the electric machine 16.

[0073] For example, the control parameter P includes the temperature outside the aircraft 2 measured by the temperature sensor 24 and the altitude of the aircraft 2 measured by the altitude sensor 26.

[0074] The temperature outside the aircraft 2 enables the viscosity of the oil of the electric motor 16 and / or the viscosity of the oil of the turbine 4 to be determined.

[0075] When the viscosity of the cooling oil of the electric motor 16 is high, the electric motor 16 exhibits a large inertia. When the viscosity of the oil of the turbine 4 is high and the coupling device 18 is in the coupled state, the electric motor 16 exhibits a large inertia.

[0076] Taking into account the altitude of the aircraft 2 enables the start-up time of the turbine 4 to be adjusted.

[0077] The higher the altitude of the aircraft 2, the longer the start-up time of the turbine 4. For example, at sea level, the start-up time of the turbine is 60 seconds, and at high altitude, the start-up time of the turbine is 120 seconds.

[0078] The control parameter P may include a parameter representing the type of fault of the electric motor 16.

[0079] For example, when the electric motor 16 is detected to be overheated by the diagnostic sensor 22, the second comparison device 38 modifies the threshold value to take into account the change in the behavior of the electric motor 16 due to overheating. When the diagnostic sensor 22 detects a defect in the bearing of the electric motor 16, the second comparison device 38 modifies the threshold value to take into account the change in the behavior of the electric motor 16 due to the bearing fault. When the diagnostic sensor 22 detects a short circuit in the electric motor 16, the second comparison device 38 modifies the threshold value to take into account the change in the behavior of the electric motor 16. When the diagnostic sensor 22 detects an abnormal pressure or an abnormal oil level, the second comparison device 38 modifies the threshold value to take into account the change in the behavior of the electric motor 16.

[0080] Of course, the parameter P may include a plurality of variables among the temperature outside the aircraft 2, the altitude of the aircraft 2, and the parameter representing the type of fault.

[0081] Alternatively, the method includes calculating the gradient of the operating deviation before the second comparison step 50 and a step of calculating the gradient of the time evolution curve, and determining the value of the detection threshold according to the control parameter P, the gradient of the operating deviation, and the gradient of the time evolution curve of the rotational speed of the electric motor 16.

[0082] Using the gradient enables the behavior deviation to be detected quickly.

[0083] According to the result of step 50, a fault of the coupling device 18 can be detected (step 52). For example, if the operating deviation is greater than the variable detection threshold, the coupling device 18 is considered to be defective. If the operating deviation is less than the detection threshold, the coupling device 18 is considered to be functioning normally.

[0084] During the delay step 54, the result transmitted by the second comparison device 38 is stored in the memory for a predetermined time, and steps 42, 44, 46, 48, and 50 are repeated, and then the result transmitted by the second comparison device 38 is compared with the result stored in the memory. If the two results are the same and indicate a fault, the device 40 for determining a fault reports the fault. Otherwise, the device 40 for determining a fault will issue a signal indicating that there is no fault.

[0085] For example, the control method is executed after a change in the state of the coupling device 18 to separate the electric machine 16 after a fault occurs in the electric machine 16, or the control method is executed when a functional test of the coupling device 18 is implemented, or the control method is executed to ensure that the coupling device 18 remains in an operating state controlled by the control device 20.

[0086] Now assume that the turbine 4 is stopped, for example, the aircraft 2 is on the ground.

[0087] The method starts with step 56 of controlling the electric machine 16 in motor mode, such that the electric machine 16 uses electrical power to generate mechanical rotational power.

[0088] Preferably, the control device 20 controls the electric machine 16 in motor mode such that the electric machine 16 generates sufficient mechanical power to rotate the rotor shaft of the electric machine 16, but not sufficient to rotate the rotating shaft 6.

[0089] Then steps 42, 44, and 46 described above are executed.

[0090] During the first comparison step 48, the rotational speed of the rotating shaft 6 is zero. The time evolution curve includes the rotational speed of the separated electric machine 16.

[0091] The method continues with steps 50, 52, and 54 as described above.

[0092] When the control device 20 controls the electric machine 16 in motor mode such that the electric machine 16 generates sufficient mechanical power to rotate the rotor shaft of the electric machine 16 and rotate the rotating shaft 6, during step 58 of preventing the rotation of the rotating shaft 6, for example, a propeller brake is activated to prevent the rotation of the rotating shaft 6.

[0093] Then the method continues to step 56.

[0094] The prevention step 58 also makes it possible to prevent an incorrect assessment of the operating state of the coupling device 18 when the rotating shaft 6 is rotated by the windmill.

[0095] By adjusting the value of the detection threshold according to the control parameter P, the operating deviation, and the rotational speed of the electric machine 16, the operating state of the turbine 4 can be considered to improve the detection of faults in the coupling device 18.

Claims

1. A method for controlling the operation of a coupling device (18) for a turbine (4) of an aircraft (2), the turbine (4) comprising a rotating shaft (6) and an electric machine (16), the coupling device (18) being configured to connect the rotor shaft of the electric machine (16) to the rotating shaft (6) and having two operating states: a coupling state to fix the rotor shaft and the rotating shaft (6); and a decoupling state to decouple the rotor shaft and the rotating shaft (6), the method comprises the following steps: - determining a control state of the coupling device (18), the control state of the coupling device being transmitted in the form of a control command in the coupling state or the decoupling state of the coupling device (18); - determining the rotational speed of the electric machine (16); - determining the rotational speed of the rotating shaft (6); - making a first comparison (48) between the determined rotational speed of the electric machine (16) and a time evolution curve of the rotational speed of the electric machine (16) determined according to the rotational speed of the rotating shaft (6) and the control state of the coupling device (18), performing the first comparison (48) to determine an operating deviation; - making a second comparison (50) between the operating deviation and a detection threshold; and - identifying whether there is a fault or no fault (52) in the coupling device (18) according to the result of the second comparison step (50); characterized in that the second comparison step (50) comprises determining the value of the detection threshold according to at least one control parameter (P), the operating deviation and the rotational speed of the electric machine (16).

2. The method according to claim 1, wherein, the control parameter (P) is selected from an external temperature, the altitude of the aircraft (2) and a parameter representing the type of fault of the electric machine (16).

3. The method according to one of claims 1 and 2, wherein, the first comparison step (48) comprises a previous step of determining a time evolution curve graph of the rotational speed of the electric machine (16) according to the rotational speed of the rotating shaft (6) and the control state of the coupling device (18).

4. The method according to any one of claims 1 to 3, wherein, the second comparison step (50) comprises steps of calculating a gradient of the operating deviation and calculating a gradient of the time evolution curve before the second comparison step (50), and determining the value of the detection threshold according to the control parameter (P), the gradient of the operating deviation, and the gradient of the determined rotational speed of the electric machine (16).

5. The method according to any one of claims 1 to 4, the method comprising a step (54) of delaying the result of the second comparison step (50).

6. The method according to any one of claims 1 to 5, the method comprising controlling the electric machine (16) to be in a motor mode when the turbine (4) stops before the step of determining (44) the rotational speed of the electric machine (16).

7. The method according to claim 6, wherein the method includes preventing rotation of the rotary shaft (6) when the electric machine (16) operates in the motor mode.

8. A module for controlling the operation of a coupling device (18) for a turbine (4) of an aircraft (2), the turbine (4) including a rotary shaft (6) and an electric machine (16), the coupling device (18) being configured to connect the rotor shaft of the electric machine (16) to the rotary shaft (6) and having two operating states: a coupled state for fixing the rotor shaft and the rotary shaft (6) ； and a disengaged state for disengaging the rotor shaft and the rotary shaft (6), the module (28) including: - a first determination device (30) configured to determine the control state of the coupling device (18), the control state of the coupling device being transmitted in the form of a control command in the coupled state or the disengaged state of the coupling device (18); - a second determination device (32) configured to determine the rotational speed of the electric machine (16), - a third determination device (34) configured to determine the rotational speed of the rotary shaft (6); - a first comparison device (36) configured to compare the rotational speed of the electric machine (16) with a time evolution curve of the rotational speed of the electric machine (16) determined based on the rotational speed of the rotary shaft (6) and the control state of the coupling device (18), the first comparison device (36) being configured to determine an operating deviation; - a second comparison device (38) configured to compare the operating deviation with a detection threshold; and - a device (40) for determining a fault, the device for determining a fault being configured to identify the presence or absence of a fault in the coupling device (18) based on the result transmitted by the second comparison device (36); wherein the second comparison device (36) is further configured to determine the value of the detection threshold based on at least one control parameter (P), the operating deviation, and the rotational speed of the electric machine (16).

9. An aircraft turbine (4) of an aircraft (2), the aircraft turbine including a rotary shaft (6), an electric machine (16), and a coupling device (18), the coupling device being configured to connect the rotor shaft of the electric machine (16) to the rotary shaft (6) and having two operating states: a coupled state for fixing the rotor shaft and the rotary shaft (6); and a disengaged state for disengaging the rotor shaft and the rotary shaft (6), characterized in that the aircraft turbine includes the control module (28) according to claim 8.

10. An aircraft (2), characterized in that the aircraft includes the turbine (4) according to claim 9.

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