Turbomachine comprising a control device for an electric machine and associated method

Abstract

An aircraft turbomachine comprising at least one propulsion shaft, an electric machine (1) connected to the propulsion shaft by a transmission line, a control device (3) comprising a correction module (4) configured to determine a correction torque (TRQcorr) to correct a torsion mode of the transmission line and a regulation module (5) configured to determine a setpoint torque (TRQcons) from a setpoint distribution voltage (Vdc_cons), a measured distribution voltage (Vdc_mes) and an angular velocity (W) of the electric machine (1) so as to ensure the quality of the electrical network (6).

Description

Turbomachine comprising a control device for an electrical machine and associated method

[0001] The present invention relates to the field of electrical machines integrated into an aircraft turbomachine for hybrid propulsion. The invention is particularly advantageous for an electric machine connected to a propulsion shaft of an aircraft turbomachine via a transmission line, this electric machine being configured to operate in motor mode to rotate the propulsion shaft or in generator mode to generate electrical power.

[0002] Climate change is a major concern for many legislative and regulatory bodies worldwide. Indeed, various restrictions on carbon emissions have been, are being, or will be adopted by different countries. In particular, an ambitious standard applies to both new types of aircraft and those already in service, requiring the implementation of technological solutions to bring them into compliance with current regulations. Civil aviation has been actively working for several years now to contribute to the fight against climate change.

[0003] Technological research efforts have already led to very significant improvements in the environmental performance of aircraft. The Applicant takes into account the factors impacting all phases of design and development in order to obtain aeronautical components and products that are less energy-intensive, more environmentally friendly, and whose integration and use in civil aviation have moderate environmental consequences, with the aim of improving the energy efficiency of aircraft.

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

[0005] This sustained research and development work focuses on new generations of aircraft engines, the weight reduction of aircraft, particularly through the materials used and lighter on-board equipment, the development of the use of electrical technologies to provide propulsion, and, as essential complements to technological progress, aviation biofuels.

[0006] It is known in the prior art to mount an electric machine on the propulsion shaft of an aircraft turbomachine, such as a fan shaft, to create a hybrid turbomachine. The electric machine is typically configured to operate in generator mode, drawing mechanical power from the propulsion shaft to generate electrical power. The electric machine is also configured to operate in motor mode, providing mechanical power to the propulsion shaft by drawing electrical power, for example, from an electric battery.

[0007] With reference to the above, in order to facilitate the integration of the electric machine 1, it has been proposed to connect it to a drive shaft of the turbomachine Ahp via a transmission line 2 comprising an internal gearbox 21 known by its English designation "IGB" for "Internal Gear Box", a radial drive shaft 22 known by its English designation "RDS" for "Radial Drive Shaft", and an accessory gearbox 23 known by its English designation "AGB" for "Accessory Gear Box". As is known, the electric machine 1 comprises a stator 11 and a rotor 12 configured to interact magnetically with the stator 11. The aircraft turbomachine 1 includes a control device 203 configured to receive a set torque TRQcons and determine the currents flowing in the stator 11 so that the rotor 12 provides an electric machine torque conforming to the set torque TRQcons.

[0008] In practice, during the operation of the transmission line 2 in motor or generator mode, a torsional mode Mt is likely to appear in the transmission line 2. A torsional mode Mt corresponds, in particular, to an oscillation of torque and speed at a torsional frequency. The torsional mode Mt can manifest itself, for example, as a torsion of the radial transmission shaft 22, that is to say, an angular displacement between two longitudinal portions of the radial transmission shaft 22.

[0009] Such a torsion mode Mt affects the performance of the transmission line 2 and can induce excitations or resonances which lead to premature wear of the elements of the transmission line 2 but also wear of the electrical machine 1.

[0010] An immediate solution would be to increase the rigidity of transmission line 2 to reduce the torsional mode Mt. Such a solution is not feasible since it would increase the mass and size of transmission line 2, thus partially negating the benefits of hybridization.

[0011] Furthermore, with reference to the above, the electrical machine 1 must supply a High Voltage Direct Current (HVDC) electrical network 6 to power electrical loads, for example, propulsion machines, turbomachinery, or aircraft electrical loads. The electrical network 6 has a distribution voltage Vdc that must remain substantially constant over time to ensure sufficient network quality.

[0012] The electrical network 6 is supplied by the electrical machine 1 via one or more electrical converters (not shown), at least one of which provides voltage regulation of the distribution voltage Vdc of the electrical network 6. To ensure high-quality voltage regulation in the event of a temporary overload (acceleration of propulsion machines, etc.), the voltage regulation must have a wide dynamic range, for example, between 150 and 200 Hz bandwidth. In practice, voltage regulation with a wide dynamic range presents the risk of exciting the torsional mode Mt, which generates poorly damped oscillations that can lead to the failure of a component of the transmission line 2.

[0013] To eliminate this drawback, one solution would be to implement voltage regulation with low dynamic range to avoid any excitation of the torsional mode Mt. However, this has the disadvantage of degrading network quality. Indeed, during temporary overloads causing disturbances, the voltage regulation will not be sufficiently responsive to reject the disturbance, which could lead to overvoltages in the electrical network or even a total network failure. Therefore, such a solution is not satisfactory.

[0014] Another solution would be to add an electrical storage battery in parallel with the electrical network 6 so that it maintains the distribution voltage Vdc during temporary overloads. This solution significantly increases the weight and size.

[0015] Prior art includes EP3472925B1 which presents a system for limiting torsional oscillations in a turbomachine, US2023 / 029626A1 which teaches an inverter for damping the oscillations of an electric motor and US2022 / 131490A1 which teaches a control system for an electric motor to improve the acoustic behavior of a motor vehicle.

[0016] The invention thus aims to eliminate at least some of these drawbacks. PRESENTATION OF THE INVENTION

[0017] The invention relates to an aircraft turbomachine comprising at least one propulsion shaft and an electric machine connected to the propulsion shaft by a transmission line configured to transmit mechanical torque between the propulsion shaft and the electric machine, the transmission line being subjected to a torsion mode having an estimated torsion frequency, the electric machine comprising a stator and a rotor configured to interact magnetically with the stator, the electric machine being configured to operate, on the one hand, in a generator mode in order to draw mechanical power from the rotor to generate electrical power and to operate, on the other hand, in a motor mode in order to consume electrical power to generate mechanical power, the electric machine being configured to supply an electrical network connected to electrical loads, the electrical network having a distribution voltage,The aircraft turbomachine includes a control device configured to determine the currents flowing in the stator so that the rotor provides an electrical machine torque conforming to a control torque; the control device includes a correction module configured to determine a correction torque to mitigate the torsion mode of the transmission line; the control device includes a regulation module configured to determine a setpoint torque from a setpoint distribution voltage, a measured distribution voltage, and an angular velocity of the electrical machine in order to ensure the quality of the electrical network; and the control device is configured to calculate the control torque from the setpoint torque and the correction torque.

[0018] Thus, thanks to the invention, the torsional mode of the transmission line is dynamically attenuated in both transient and steady-state conditions, thereby increasing the service life of the electrical machine and the transmission line by reducing torque variations in the electrical machine. Torsion mode correction is performed synergistically with the power quality management of the electrical network supplied by the electrical machine. Therefore, there is no risk that torsion mode correction will cause voltage excursions outside the acceptable voltage range at any given time, or even a complete power outage.

[0019] Torsion mode correction is also advantageous when the electric machine operates in motor or generator mode. Transitions between the two modes are also facilitated. In steady-state operation, the correction is minimal, thus conserving the electric machine and preventing unnecessary use. Furthermore, since the damping is performed via software, there is no need to add a mechanical component whose mass would be detrimental and would require replacement. Advantageously, no new sensors need to be added to the electric machine, simplifying integration.

[0020] According to one aspect, the transmission line includes at least one radial drive shaft and an accessory relay box.

[0021] According to one aspect, the control module is configured to: Determine a distribution error from the setpoint distribution voltage and the measured distribution voltage, preferably from the squares of said voltages, Determine a first power by applying a phase lead to the distribution error, Determine a second power by applying an anticipation parameter to the distribution error, Determine a setpoint power by subtracting the second power from the first power, and Determine a setpoint torque from the setpoint power and the angular speed of the electric machine.

[0022] Thanks to the invention, the control module allows for adjusting the system's dynamic performance and ensuring system stability while taking into account the estimated torsional mode frequency, which is rejected via a high-frequency anticipatory action. Any excitation related to the torsional mode is thus eliminated. The combination of two control loops makes it possible to determine a setpoint torque that is compatible with the torsional mode correction and that meets the required voltage specifications. This maintains an acceptable voltage range while mitigating the torsional mode.

[0023] In one aspect, the control module comprises a first control channel configured to determine the initial power output by applying a phase lead to the distribution error, a second control channel configured to determine the second power output by applying an anticipation parameter to the distribution error, and a subtractor configured to determine a setpoint power by subtracting the second power output from the first power output. The second control channel also allows for the rejection of disturbances related to rapid DC voltage variations. Furthermore, this second channel is unaffected by oscillations related to the torsion mode.

[0024] In one aspect, the first control channel includes a phase-lead compensator with a setting frequency that is approximately equal to the estimated torsional frequency of the torsional mode. This compensator improves the system's stability.

[0025] In one aspect, the first control channel includes a PI controller that allows for adjusting the system dynamics (proportional action) and suppressing steady-state error (integral action). This allows the phase-lead controller output to be inverted to determine the initial power.

[0026] In one aspect, the second regulation channel includes a high-pass filter with a cutoff frequency at least twice the estimated twisting mode frequency. This allows the estimated twisting mode frequency to be taken into account and rejected to ensure network quality. Any unacceptable degradation of network quality due to twisting mode correction is thus avoided.

[0027] According to one aspect, the control module includes a divider configured to determine the setpoint torque from the setpoint power and the angular speed of the electric machine.

[0028] In one respect, the distribution deviation between the setpoint distribution voltage and the measured distribution voltage is a quadratic deviation which is easier to regulate.

[0029] According to one aspect, the correction module is configured to: Determine a time measurement of a rotor torque parameter designated "time measurement", over a frequency range encompassing the estimated twisting frequency, designated "monitoring range", and Calculate a correction torque from the time measurement over the monitoring range.

[0030] Preferably, the monitoring range has a length between 10 Hz and 50 Hz. Such a short length makes it possible to target the actual twisting frequency precisely while allowing an permissible variation related to wear, the particular characteristics of each transmission line and the level of load of the transmission line (level of applied torque).

[0031] The invention also relates to a method for correcting the torsion mode of the transmission line of the aircraft turbomachine as previously described, the method comprising steps of: Determining a correction torque to attenuate the torsion mode of the transmission line, Determining a setpoint torque from the setpoint distribution voltage, the measured distribution voltage and the angular velocity of the electric machine and Calculating a control torque from the setpoint torque and the correction torque. PRESENTATION OF THE FIGURES

[0032] The invention will be better understood upon reading the following description, given by way of example, and referring to the following figures, given by way of non-limiting examples, in which identical references are given to similar objects.

[0033] This is a schematic representation of an aircraft turbomachine according to the prior art of the hybridized type.

[0034] This is a schematic representation of an aircraft turbomachine according to one embodiment of the invention.

[0035] This is a schematic representation of the electrical machine control device comprising a correction module and a regulation module.

[0036] This is a schematic representation of the torsion mode correction module.

[0037] This is a schematic representation of the voltage regulation module.

[0038] This is a schematic representation of the measurement of the torsional torque at the level of the adaptation box, in time (curve 6a) and in frequency (curve 6b), when the correction is inactive.

[0039] This is a schematic representation of the impact of a temporary overload on the power consumed (curve 7a), on the distribution voltage (curve 7b) and on the torque of the electric machine (curve 7c).

[0040] It should be noted that the figures explain the invention in detail for implementing the invention, said figures being of course able to serve to better define the invention where appropriate. DETAILED DESCRIPTION OF THE INVENTION

[0041] With reference to the diagram, an aircraft turbomachine T is shown comprising a low-pressure compressor 101, a high-pressure compressor 102, a high-pressure turbine 103, and a low-pressure turbine 104. A low-pressure shaft Abp connects the low-pressure compressor 101 to the low-pressure turbine 104. A high-pressure shaft Ahp connects the high-pressure compressor 102 to the high-pressure turbine 103. A fan 100 is mounted integrally with the low-pressure shaft Abp. The aircraft turbomachine T includes a combustion chamber (not shown) for consuming a mixture of fuel and a pressurized airflow accelerated by the compressors 101 and 102. An exhaust flow drives the turbines 103 and 104. Both the high-pressure shaft Ahp and the low-pressure shaft Abp are propulsion shafts, as they are main shafts that contribute to propulsion.The architecture of such a T aircraft turbomachine is known to those skilled in the art and will not be presented in further detail.

[0042] In this example, the aircraft turbomachine T is hybrid and comprises an electric machine 1 connected to the high-pressure shaft Ahp by a transmission line 2 configured to transmit mechanical torque between the high-pressure shaft Ahp and the electric machine 1. It is understood, however, that the invention also applies to an electric machine 1 connected to the low-pressure shaft Abp by a transmission line 2 or to any other transmission shaft. In particular, a machine could be associated with each propulsion shaft or with an intermediate transmission shaft for a triple-shaft turbomachine.

[0043] In this example, with reference to the, the transmission line 2 preferably comprises successively from the high pressure shaft Ahp to the electric machine 1: an internal transmission box 21, known by its English designation "IGB" for "Internal Gear Box", a radial drive shaft 22, known by its English designation "RDS" for "Radial Drive Shaft", an accessory relay box 23, known by its English designation "AGB" for "Accessory Gear Box", and an adapter box 24, known by its English designation "GBX" for "GearBox".

[0044] The internal transmission housing 21 contains gears and is located as close as possible to the high-pressure shaft Ahp to transmit / receive power. The radial transmission shaft 22 preferably extends within a radial arm of the turbomachine T to traverse an air stream accelerated by the fan 100. The radial transmission shaft 22 has a degree of flexibility and is particularly sensitive to a torsion mode Mt. The accessory relay housing 23 contains a plurality of gears to receive various accessories such as a starter, a lubrication device, etc.

[0045] In this example, optionally, the transmission line 2 includes an adapter 24 configured to adapt the speed from the accessory relay box 23 to allow the electric machine 1 to generate electrical power with high efficiency. Preferably, the adapter 24 includes a device for measuring the torque of the transmission line 2, in particular a torque meter.

[0046] It goes without saying that transmission line 2 could have a different structure.

[0047] As previously mentioned, the transmission line 2 is subjected to a torsional mode Mt with an actual torsional frequency Ftr that is not necessarily known precisely. Indeed, the actual torsional frequency Ftr varies between each aircraft turbomachine T and between each transmission line 2 due to different settings and wear. The actual torsional frequency Ftr thus evolves according to time and conditions.

[0048] The transmission line 2 can be modeled by a damping system connecting, on the one hand, the electrical machine 1, which has high rigidity, and, on the other hand, the high-pressure shaft Ahp. The damping system has a torsional stiffness with two degrees of freedom in the frame of reference of the electrical machine 1. The torsional stiffness is advantageously defined in a plane orthogonal to the axis of the electrical machine 1.

[0049] As will be shown later, the correction is optimal in the present case since the inertia ratio of the electric machine 1 on the high-pressure shaft Ahp is low, for example, on the order of 1 / 40.

[0050] The torsion mode Mt can manifest itself for example in the form of a torsion of the radial transmission shaft 22, that is to say, an angular offset between two longitudinal portions of the radial transmission shaft 22.

[0051] As an example, with reference to the, a measurement of the mechanical torque received by the adaptation box 24 is shown in the absence of time (curve 6a) and frequency (curve 6b) correction.

[0052] As will be shown later, an estimated torsion frequency Fte is determined by calculation, in particular, from a mathematical model of the transmission line 2, by simulation or by feedback from experience.

[0053] Advantageously, a frequency range encompassing the estimated torsional frequency Fte, designated the "monitoring range Ps," is determined from the estimated torsional frequency Fte. This monitoring range Ps has a lower bound Fte1 and an upper bound Fte2. The monitoring range Ps is preferably centered on the estimated torsional frequency Fte, but it is understood that it could be offset from said estimated torsional frequency Fte.

[0054] Preferably, the monitoring range Ps has a length, i.e., a difference between its lower bound Fte1 and its upper bound Fte2, of between 10 Hz and 50 Hz. Such a monitoring range Ps is wide enough to encompass the possible variations of the estimated torsional frequency Fte and narrow enough to avoid encompassing undesirable frequencies. Preferably, the lower bound Fte1 is between Fte / 3 and Fte / 2. Preferably, the upper bound Fte2 is between 2*Fte and 3*Fte.

[0055] With reference to the diagram, the electric machine 1 comprises a stator 11 fixedly mounted in the turbomachine T and a rotor 12 connected to the transmission line 2, specifically to the adapter box 24. In the absence of an adapter box 24, the rotor 12 is directly connected to the accessory relay box 23. The rotor 12 is rotatable relative to the stator 11 along an electric machine axis X. The rotor 12 is configured to interact magnetically with the stator 11. The electric machine 1 is, for example, a permanent magnet synchronous machine (PMSM) or a wound-rotor machine. The electric machine used is, for example, a permanent magnet synchronous machine mounted on the rotor surface without a mechanical damper.

[0056] The electric machine 1 is configured, on the one hand, to operate in generator mode in order to take mechanical power from the rotor 12 (from the high pressure shaft Ahp in this example) to generate electrical power and to operate, on the other hand, in motor mode in order to consume electrical power to generate mechanical power and drive the rotor 12 and the high pressure shaft Ahp.

[0057] With reference to the diagram, the electrical machine 1 is configured to supply an electrical network 6 connected to electrical loads, in particular, propulsion electric motors. The electrical network 6 has a high direct current voltage. Such an electrical network 6 is known by its acronym HVDC for (High Voltage Direct Current). The electrical network 6 has a distribution voltage Vdc which is preferably between 800 and 1500 Vdc.

[0058] With further reference to the, the aircraft turbomachine T also includes a control device 3 configured to determine the currents flowing in the stator 11 so that the rotor 12 provides an electrical machine torque TRQ conforming to a control torque TRQ* as illustrated in the.

[0059] An example of the implementation of a control device 3 is illustrated in Figure 1. The control device 3 includes, as is known, a unit for determining a quadrature setpoint current Iq* from the control torque TRQ*. The control device 3 also includes a unit for determining a forward setpoint current Id*. The setpoint currents Iq*, Id* are converted into setpoint voltages Vq*, Vd* by a conversion unit 33 after integration of the setpoint currents Iq*, Id* by PI (Proportional-Integral) operators from current measurements of the currents Iq, Id flowing in the stator 11 of the electrical machine 1.

[0060] In this example, currents Iabc are measured at the stator 11 of the electric machine 1 and are vectorially converted into a forward current Id and a reverse current Iq by knowing an angular velocity W of the rotor 12 relative to the stator 11. The electric machine 1 is controlled via a vector control dq as illustrated in Figure 1. Alternatively, the angular position of the rotor 12 could also be measured.

[0061] The conversion unit 33 determines the setpoint voltages Vq*, Vd* by knowing the angular velocity W of the rotor 12 relative to the stator 11 in order to perform flux defluxing. Preferably, the angular velocity W of the rotor 12 is obtained by integrating the angular position θ.

[0062] According to one aspect, the angular position θ of the rotor 12 relative to the stator 11 is obtained by a monitoring unit 36 ​​which can be connected to an angular sensor 37 or to an observation unit (not shown) which allows the angular position θ to be determined from the measurement of the control currents Iabc.

[0063] The setpoint voltages Vq*, Vd* from the conversion unit 33 are transformed into control voltage Vabc* by a dq / abc converter and then processed by a control unit 34 in order to provide a control parameter (PWM signal for example) to an inverter 35 supplying the electrical machine 1, in particular, its stator 11.

[0064] The general structure of a control device 3 is known to a person skilled in the art and will not be presented in more detail.

[0065] According to the invention, the control device 3 comprises a correction module 4 configured to determine a correction torque TRQcorr to mitigate the torsional mode Mt of the transmission line 2 and a regulation module 5 configured to determine a setpoint torque TRQcons from a setpoint distribution voltage Vdc_cons, a measured distribution voltage Vdc_mes, and the angular velocity W of the electrical machine 1 in order to ensure the quality of the electrical network 6. The control device 3 is configured to calculate the control torque TRQ* from the setpoint torque TRQcons and the correction torque TRQcorr. The angular velocity W advantageously allows the torque setpoint to be determined.

[0066] Thus, according to the invention, the setpoint torque TRQcons is determined dynamically to ensure the quality of the electrical network 6 by maintaining the distribution voltage Vdc at all times within the acceptable voltage range to supply electrical loads, particularly when they are propulsive. Advantageously, the correction torque TRQcorr eliminates impacts related to the torsion mode Mt, thereby preventing any mechanical oscillation that could cause damage.

[0067] Advantageously, the distribution voltage Vdc is maintained within acceptable limits both in steady state and during transient phases.

[0068] According to the invention, with reference to the, the correction module 4 is configured to attenuate the excitation of the torsion mode Mt of the transmission line 2. This advantageously reduces the torque variations of the electric machine 1 and thus improves its service life.

[0069] The correction module 4 is configured to: Determine a time measurement Mw of the variations of a torque parameter of the rotor 12 of the electric machine 1, hereafter referred to as the "time measurement", and Calculate a correction torque TRQcorr from the time measurement Mw over the monitoring range Ps.

[0070] The control device 3 is configured to calculate a control torque TRQ* from the setpoint torque TRQcons and the correction torque TRQcorr. In this example, with reference to the diagram, the control device 3 includes a subtractor 38 configured to determine the control torque TRQ* by subtracting the correction torque TRQcorr from the setpoint torque TRQcons.

[0071] Thus, the correction module 4 measures the variations induced by the torsion mode Mt in order to determine a correction torque TRQcorr, which modifies the setpoint torque TRQcons. In other words, the correction module 4 implements active and dynamic compensation to control the electric machine 1, taking into account the torsion mode Mt to increase its lifespan. The correction torque TRQcorr is injected in opposite phase to the torque and speed perturbation associated with the torsion mode Mt, thereby creating a damping effect.

[0072] With reference to the diagram, a schematic representation of a correction module 4 is shown. In this example, the correction module 4 successively comprises a low-pass filter 41, a high-pass filter 42, a gain operator 43 having a gain Kp1 and a saturator 44.

[0073] The low-pass filter 41 is configured to perform a frequency cutoff at the upper limit Fte2 of the monitoring range Ps. This advantageously removes high-frequency noise that is not related to the torsion mode Mt. Such a low-pass filter 41 is optional when the time measurement Mw has been obtained by a monitoring unit 36 ​​that already implements low-pass filtering.

[0074] The high-pass filter 42 is configured to perform a frequency cutoff at the lower limit Fte1 of the monitoring range Ps. This advantageously removes the DC component of the time measurement, leaving only the wave component.

[0075] The gain operator 43 determines the desired correction level. It is preferably determined based on the torsional stiffness of the damping system representing transmission line 2. The gain Kp1 calibrates the correction to ensure it is effective while avoiding the risk of instability.

[0076] The saturator 44 advantageously limits the value of the correction torque TRQcorr to prevent instability while still allowing for responsive correction. It is important that the correction torque TRQcorr remains low relative to the setpoint torque TRQcons, for example, less than 10% in the transient regime of the turbomachine T and less than 1% in steady state.

[0077] According to the invention, with reference to the, the control device 3 comprises a regulation module 5 configured to ensure the network quality of the electrical distribution network 6.

[0078] With reference to the, the control module 5 is configured to determine a setpoint torque TRQcons from the setpoint distribution voltage Vdc_cons, the measured distribution voltage Vdc_mes and the angular velocity W of the electric machine 1. This advantageously reduces variations in the distribution voltage Vdc, in particular, when correcting the torsion mode Mt.

[0079] As illustrated in Figure 1, the control module 5 includes a subtractor 51 configured to determine a distribution error ΔVdc from the setpoint distribution voltage Vdc_cons and the measured distribution voltage Vdc_mes. In this example, the distribution error ΔVdc is a quadratic error defined by the following formula: ΔVdc = Vdc_cons² - Vdc_mes 2 .

[0080] The control module 5 includes, on the one hand, a first control channel V1 configured to determine a first power P1 by applying a phase-lead action followed by a Proportional-Integral action to the distribution deviation ΔVdc and, on the other hand, a second control channel V2 configured to determine a second power P2 by applying an anticipation parameter to the distribution deviation ΔVdc.

[0081] With further reference to the first control channel V1, a phase-lead controller 52 and a PI (proportional-integral) controller 53 are included to improve the phase margin of the distribution voltage Vdc and thus its stability, while eliminating static error and regulating dynamics. This allows for dynamic performance adjustment while simultaneously improving stability. The phase-lead controller 52 has a tuning frequency Fr that is substantially equal to the estimated twisting frequency Fte. In particular, the difference between the tuning frequency Fr and the estimated twisting frequency Fte is less than 10%.

[0082] As illustrated in the figure, the second regulation channel V2 includes a high-pass filter 54 having a cutoff frequency Fc which is at least twice the estimated twist frequency Fte (Fc > 2*Fte), which improves the behavior with respect to noise.

[0083] The second regulation channel V2 includes a gain operator 55 with a gain Kp2 to multiply the output of the high-pass filter 54 in order to provide the second "high-frequency" power P2. This second "high-frequency" power P2 allows for anticipating rapid variations in the distribution voltage Vdc during a temporary overload. The gain operator 55 determines the desired correction level. This anticipatory action is achieved using a high-pass filter whose cutoff frequency is preferably at least twice the estimated twist frequency Fte, rather than through a derivative action that could result in a very high value in the presence of noise.

[0084] The Kp2 gain allows you to calibrate the correction for effectiveness. It represents a compromise between the level of correction required and maintaining stability.

[0085] With further reference to the control module 5, it includes a subtractor 56 configured to determine a setpoint power Pcons by subtracting the second power P2 from the first power P1. The control module 5 also includes a divider 57 configured to determine the setpoint torque TRQcons from the setpoint power Pcons and the angular velocity W of the electric machine 1.

[0086] The control device 3 thus allows a control system to guarantee network quality and avoid reinjecting a disturbance linked to mechanical oscillations present on the transmission line 2.

[0087] An example of the implementation of a method for correcting a torsion mode of transmission line 2 will now be presented.

[0088] The process includes steps of: Determining a correction torque TRQcorr to attenuate the torsion mode (Mt) of the transmission line 2, Determining a setpoint torque TRQcons from the setpoint distribution voltage Vdc_cons, the measured distribution voltage Vdc_mes and the angular velocity W of the electrical machine 1, and Calculating a control torque TRQ* from the setpoint torque TRQcons and the correction torque TRQcorr.

[0089] To calculate the correction torque TRQcorr, the process includes the steps of: Determining a time measurement Mw of a rotor torque parameter 12 designated "time measurement Mw", over a frequency range encompassing the estimated twisting frequency Fte, designated "monitoring range Ps", and Calculating a correction torque TRQcorr from the time measurement Mw over the monitoring range Ps.

[0090] To calculate the setpoint torque TRQcons, the process includes the following steps: Determining the distribution error ΔVdc from the setpoint distribution voltage Vdc_cons and the measured distribution voltage Vdc_mes; Determining a first power P1 by applying a phase-lead action and a Proportional-Integral action to the distribution error ΔVdc; Determining a second power P2 by applying an anticipation parameter to the distribution error ΔVdc; Determining a setpoint power Pcons by subtracting the second power P2 from the first power P1; and Determining the setpoint torque TRQcons from the setpoint power Pcons and the angular speed of the electrical machine 1.

[0091] Advantageously, the first power P1 applies a phase advance 52 with a tuning frequency Fr that is substantially equal to the estimated torsion frequency Fte. This synergistically allows the torsion mode Mt of the transmission line 2 to be taken into account during the torsion mode correction. Indeed, this advantageously improves the phase margin.

[0092] The curve of 7a illustrates a power demand P at a time instant t0. Such a power demand, in the form of a step, is for example linked to an increase in the need of electrical loads connected to the electrical network 6 during a transient phase, for example, during a sudden power demand of the electric propulsion machines.

[0093] At time t0, the power demand P causes a drop in the distribution voltage Vdc illustrated in curve 7b. This results in an increase in the distribution deviation ΔVdc.

[0094] With correction or regulation in place, the distribution voltage Vdc (thin line on curve 7b) drops during the transient (load inrush) and returns to its reference value in a time comparable to that when this regulation is not implemented (thick line on curve 7b). The distribution voltage Vdc exhibits negligible oscillations in steady state due to the continuous correction of the torsion mode. Oscillations related to the torsion mode are present in the voltage regulation because the nested torque loop compensates for the torque oscillations that are found in the voltage loop (higher-level loop).

[0095] Network quality is improved because the distribution voltage Vdc remains permanently within the voltage range in both transient and stabilized regimes.

[0096] Similarly, without correction or regulation (thin line on curve 7c), the oscillations of the mechanical torque TRQ of the electrical machine 1 are high due to the presence of the torsional mode Mt. Conversely, with correction and regulation (thick line on curve 7c), the mechanical torque TRQ stabilizes rapidly to dampen the torsional mode Mt.

[0097] Thanks to this invention, the torsion mode of a transmission line in a hybrid turbomachine can be effectively corrected by dynamically controlling the electric machine, thereby increasing its service life. Furthermore, by considering grid quality during torsion mode correction, any correction that could lead to voltage excursions outside the acceptable voltage range at any given time, or even to a complete power outage, is avoided. Dynamic performance is always maintained through voltage regulation while simultaneously mitigating torsion mode excitation. An external power source (battery, etc.) is not required, thus reducing mass and size.

Claims

Aircraft turbomachine (T) comprising at least one propulsion shaft (Ahp) and an electric machine (1) connected to the propulsion shaft (Ahp) by a transmission line (2) configured to transmit mechanical torque between the propulsion shaft (Ahp) and the electric machine (1), the transmission line (2) being subjected to a torsion mode (Mt) having an estimated torsion frequency (Fte), the electric machine (1) comprising a stator (11) and a rotor (12) configured to interact magnetically with the stator (11), the electric machine (1) being configured to operate, on the one hand, in a generator mode to draw mechanical power from the rotor (12) to generate electrical power and to operate, on the other hand, in a motor mode to consume electrical power to generate mechanical power, the electric machine (1) being configured to supply an electrical network (6) connected to electrical loads,the electrical network (6) having a distribution voltage (Vdc), the aircraft turbomachine (T) comprising a control device (3) configured to determine the currents flowing in the stator (11) so that the rotor (12) provides an electrical machine torque (TRQ) conforming to a control torque (TRQ*), the control device (3) comprising a correction module (4) configured to determine a correction torque (TRQcorr) to mitigate the torsion mode (Mt) of the transmission line (2), the control device (3) comprising a regulation module (5) configured to determine a setpoint torque (TRQcons) from a setpoint distribution voltage (Vdc_cons), a measured distribution voltage (Vdc_mes) and an angular velocity (W) of the electrical machine (1) so as to ensure the quality of the electrical network (6),and the control device (3) being configured to calculate the control torque (TRQ*) from the setpoint torque (TRQcons) and the correction torque (TRQcorr), the regulation module (5) being configured to: Determine a distribution error (ΔVdc) from the setpoint distribution voltage (Vdc_cons) and the measured distribution voltage (Vdc_mes), Determine a first power (P1) by applying a phase lead to the distribution error (ΔVdc), Determine a second power (P2) by applying an anticipation parameter to the distribution error (ΔVdc), Determine a setpoint power (Pcons) by subtracting the second power (P2) from the first power (P1), and Determine a setpoint torque (TRQcons) from the setpoint power (Pcons) and the angular velocity (W) of the electric machine (1). Aircraft turbomachine (T) according to claim 1, wherein the control module (5) comprises a first control channel (V1) configured to determine the first power (P1) by applying a phase lead to the distribution gap (ΔVdc), a second control channel (V2) configured to determine the second power (P2) by applying an anticipation parameter to the distribution gap (ΔVdc) and a subtractor (56) configured to determine a setpoint power (Pcons) by subtracting the second power (P2) from the first power (P1). Aircraft turbomachine (T) according to claim 2, wherein the first control channel (V1) includes a phase-lead compensator (52) having a setting frequency (Fr) that is substantially equal to the estimated twisting frequency (Fte) of the twisting mode (Mt). Aircraft turbomachine (T) according to any one of claims 2 to 3, wherein the first control channel (V1) includes a PI corrector (53). Aircraft turbomachine (T) according to any one of claims 2 to 4, wherein the second control channel (V2) includes a high-pass filter (54) having a cutoff frequency (Fc) that is at least greater than twice the estimated twisting mode frequency (Fte). Aircraft turbomachine (T) according to any one of claims 1 to 5, wherein the control module (5) includes a divider (57) configured to determine the set torque (TRQcons) from the set power (Pcons) and the angular velocity (W) of the electric machine (1). Aircraft turbomachine (T) according to any one of claims 1 to 6, wherein the distribution deviation (ΔVdc) between the setpoint distribution voltage (Vdc_cons) and the measured distribution voltage (Vdc_mes) is a quadratic deviation. Aircraft turbomachine (T) according to any one of claims 1 to 7, wherein the correction module (4) is configured to: Determine a time measurement (Mw) of a rotor torque parameter (12) designated "time measurement (Mw)", over a frequency range encompassing the estimated twisting frequency (Fte), designated "monitoring range (Ps)", and Calculate a correction torque (TRQcorr) from the time measurement (Mw) over the monitoring range (Ps). Method for correcting the torsion mode of the transmission line (2) of the aircraft turbomachine (T) according to any one of claims 1 to 8, the method comprising steps of: Determining a correction torque (TRQcorr) to attenuate the torsion mode (Mt) of the transmission line (2), Determining a setpoint torque (TRQcons) from the setpoint distribution voltage (Vdc_cons), the measured distribution voltage (Vdc_mes) and the angular velocity (W) of the electric machine (1) and Calculating a control torque (TRQ*) from the setpoint torque (TRQcons) and the correction torque (TRQcorr).

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