Electrical generation system and method, for supplying power to at least one electrical network of an aircraft
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- SAFRAN ELECTRICAL & POWER
- Filing Date
- 2024-09-23
- Publication Date
- 2026-07-01
Smart Images
Figure EP2024076616_27032025_PF_FP_ABST
Abstract
Description
Electrical generation system and method for powering at least one electrical network of an aircraft
[0001] The present invention relates to an electrical generation system for an aircraft.
[0002] Climate change is a major concern for many legislative and regulatory bodies around the world. Indeed, various restrictions on carbon emissions have been, are being, or will be adopted by various states. In particular, an ambitious standard applies both to new aircraft types and to those already in operation, requiring the implementation of technological solutions to comply with current regulations. For several years now, civil aviation has been mobilizing 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 consideration the impact factors in all phases of design and development to obtain less energy-intensive, more environmentally friendly aeronautical components and products whose integration and use in civil aviation have moderate environmental consequences with the aim of improving the energy efficiency of aircraft.
[0004] This ongoing research and development work focuses in particular on new generations of hybrid thermal and electric aircraft engines. The Applicant's objective is in particular to develop aircraft integrating a high-power electrical generation system. This would make it possible to increase the proportion of electrical equipment on board in order to reduce fuel consumption.
[0005] In practice, in a conventional aircraft turbomachine, it is known to integrate an electric generator which draws mechanical energy from a single shaft of the aircraft turbomachine to produce electrical energy which is distributed to an electrical energy distribution unit.
[0006] To increase the generation of electrical energy, with reference to the, an electrical generation system 100 has been proposed configured to take, on the one hand, mechanical energy from a low pressure shaft LP and, on the other hand, mechanical energy from a high pressure shaft HP of an aircraft turbomachine T to supply an electrical network of the aircraft REA with a calibrated distribution voltage. In other words, the electrical generation system 100 comprises at least two supply paths, here, a LP path and an HP path. The electrical generation system 100 can also be connected to electrical sources BAT or electrical loads LOAD.
[0007] In practice, the electrical generation system 100 is configured to receive a generation instruction P ECU from an ECU calculator of the turbomachine T. This generation instruction P ECUallows to determine, for example, the quantity of electrical power to be generated, the mechanical draw on each tree, etc. In other words, the generation setpoint P ECU allows the hybridization strategy to be determined.
[0008] With reference to the, the electrical generation system 100 comprises two generators G1, G2 connected respectively to the low pressure shaft LP and to the high pressure shaft HP of the turbomachine T. The electrical generation system 100 further comprises two converters C1, C2, in particular inverters, which are respectively associated with the two generators G1, G2. Each generator G1, G2 generates an alternating current which is then rectified by its converter C1, C2 to provide a distribution voltage V DC to an EDU power distribution unit which is electrically connected to the aircraft electrical network REA, to the BAT electrical sources or to the LOAD electrical loads.
[0009] This example presents an application related to electrical generation, but the invention applies more generally to the field of hybridization in which an electric machine fulfills, on the one hand, a generator function to take mechanical power from the low pressure shaft LP or from the high pressure shaft HP and, on the other hand, a motor function to inject mechanical power into the low pressure shaft LP or into the high pressure shaft HP. For a motor function, each converter C1, C2 can also convert the direct voltage V DC to supply alternating current respectively to the two electrical machines G1, G2 in order to inject power.
[0010] For the sake of clarity and conciseness, only the generator function is shown. For an engine function, the ECU provides an injection setpoint P ECUallowing to determine, for example, the injection of mechanical power on each shaft, etc. The hybridization system is bidirectional to allow the generation of electrical power but also the injection of mechanical power.
[0011] In a known manner, each converter C1, C2 comprises a plurality of switches, in particular power transistors, which make it possible to modify the electrical power generated and the electrical power taken by each generator G1, G2 on each shaft BP, HP. The electrical generation system 100 comprises a control device 200 for issuing parameter setting instructions P CONS1 , P CONS2 to each converter C1, C2 depending on the generation setpoint P ECU so as to obtain a distribution voltage V DC which is suitable for the EDU power distribution unit.
[0012] In practice, paralleling converters C1, C2 must be done with appropriate control laws to guarantee the quality of the electrical network and the control of power sharing. Several voltage control strategies can be applied. In particular, a centralized control strategy is known, in which the control of the different electrical equipment is carried out by a single voltage control loop. However, this strategy does not allow independent control of each electrical converter C1, C2.
[0013] It is known to use a decentralized control strategy, in which the voltage of each electrical device is controlled by a different control loop. To achieve this decentralized strategy, it is known to use a "Droop" type control, known to those skilled in the art, allowing independence of the control loops. This type of control, however, has the disadvantage of causing the creation of a static error in the output control. Indeed, when a disturbance is detected, each control loop will seek to compensate for it. These compensations can cause a divergence of the control. This creates instability in the electrical generation system. It is known to correct this static error by using communication between the control loops, but this then removes the independence of each control loop and increases the complexity.
[0014] The invention thus aims to eliminate at least some of these drawbacks in order to obtain independent control of several electrical supply channels. PRESENTATION OF THE INVENTION
[0015] The invention relates to an electrical generation method for supplying at least one electrical network of an aircraft from an electrical generation system, the aircraft comprising at least one aircraft turbomachine, the electrical system comprising two supply paths, each supply path comprising an electrical converter and an electrical generator driven by the turbomachine, the electrical system comprising two regulation units associated respectively with each supply path, each regulation unit comprising a correction module comprising an integral corrector, the method comprising steps consisting of, for said correction module,:Determining a power setpoint, from a distribution voltage setpoint and a measurement of the distribution voltage,Determining a divergence indicator from a gradient of the power setpoint,Reset the integral corrector of the feeder control unit according to the divergence indicator.,
[0016] Resetting the integral corrector during a divergence eliminates any risk of temporary instability to optimally generate energy for an aircraft. The invention advantageously prevents divergence of the regulating units without communication between the power supply channels, and thus allows stable independent control without static error of each power supply channel.
[0017] In one aspect, the divergence indicator is determined from the comparison between the gradient of the power setpoint and a predetermined gradient threshold. The determined gradient threshold allows the sensitivity of the reset to be adjusted.
[0018] According to one aspect, a time variation limitation is applied to the power setpoint based on a predetermined gradient threshold in order to determine a threshold value. The divergence indicator is determined from the comparison between the power setpoint and the threshold value. This divergence indicator activates the reset of the integral corrector. The predetermined gradient threshold makes it possible to adjust the sensitivity of the reset.
[0019] According to one aspect, the control unit comprises a proportional corrector.
[0020] According to one aspect, the regulation unit comprises a derivative corrector.
[0021] In one aspect, the integral corrector and the proportional corrector are connected in cascade. In another aspect, the integral corrector and the proportional corrector are connected in series. The control units can be freely determined. This advantageously allows them to be adapted according to the requirements.
[0022] The invention also relates to an electrical generation system for supplying at least one electrical network of an aircraft comprising at least one turbomachine, the electrical system comprising two supply paths, each supply path comprising an electrical converter and an electrical generator driven by the turbomachine, the electrical system comprising a control device, the control device comprising two regulation units associated respectively with each supply path, each regulation unit comprising a correction module comprising an integral corrector, each regulation unit being configured to:Determine a power setpoint, from a distribution voltage setpoint and a measurement of the distribution voltage,Determine a divergence indicator from a gradient of the power setpoint,Reset the integral corrector of the feeder control unit according to the divergence indicator.,
[0023] The invention also relates to an electrically hybridized turbomachine comprising an electrical generation system as presented previously.
[0024] The invention also relates to an aircraft comprising at least one turbomachine as presented previously.
[0025] The invention also relates to a computer program type product, comprising at least one sequence of instructions stored and readable by a processor and which, once read by this processor, causes the steps of the method as presented previously to be carried out.
[0026] The invention further relates to a computer-readable medium comprising the computer program product as presented above. PRESENTATION OF FIGURES
[0027] 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.
[0028] This is a schematic representation of an electrical generation system drawing mechanical energy from an aircraft turbomachine.
[0029] This is a schematic representation of the electrical generation system with its generators, converters, a power distribution unit and a control device.
[0030] This is a schematic representation of an electrical generation system according to the invention.
[0031] This is a schematic representation of a control device according to the invention.
[0032] This is a schematic representation of a first embodiment of a control unit according to the invention, having controllers connected in series.
[0033] This is a schematic representation of a second embodiment of a control unit according to the invention, having controllers connected in parallel.
[0034] This is a schematic representation of a first embodiment of a divergence determination module according to the invention.
[0035] This is a schematic representation of a second embodiment of a divergence determination module according to the invention.
[0036] It should be noted that the figures set out the invention in detail to implement the invention, said figures can of course be used to better define the invention where appropriate. DETAILED DESCRIPTION OF THE INVENTION
[0037] With reference to the, there is shown an electrical generation system 1 for an aircraft. The aircraft comprises a turbomachine T comprising a low pressure shaft LP and a high pressure shaft HP. In this example, the turbomachine T comprises a low pressure compressor 71 and a low pressure turbine 74 which are connected by the low pressure shaft LP and a high pressure compressor 72 and a high pressure turbine 73 which are connected by the high pressure shaft HP.
[0038] The electrical generation system 1 is configured to draw, on the one hand, mechanical energy from the low pressure shaft BP and, on the other hand, mechanical energy from the high pressure shaft HP to supply an electrical network of the aircraft REA with a calibrated voltage. The electrical generation system 1 can also be connected to electrical sources BAT or electrical equipment to be supplied LOAD.
[0039] In practice, as will be presented later, the electrical generation system 1 more generally allows electrical hybridization to allow power to be taken from or injected into the turbomachine T.
[0040] The electrical generation system 1 is configured to receive a generation setpoint P ECU from an ECU calculator of the turbomachine T. This generation instruction P ECU allows to determine, for example, the quantity of electrical power to be generated, the mechanical draw on each tree, etc. In other words, the generation setpoint P ECU allows the hybridization strategy to be determined. In practice, the generation instruction P ECU comes in the form of a power setpoint called “Setpoint PS” or a power sharing setpoint called “Mode PS”.
[0041] With reference to the, the electrical generation system 1 comprises two generators G1, G2 connected respectively to the low pressure shaft LP and to the high pressure shaft HP of the turbomachine T. The electrical generation system 1 comprises a first supply path V1 and a second supply path V2 which are, in this example, independent.
[0042] The first power supply path V1 comprises: A first generator G1 configured to generate an alternating current by taking mechanical energy from the low pressure shaft BP and A first converter C1, associated with the first generator G1, to convert the generated alternating current into a first distribution intensity according to its setting, the first converter C1 generating a first power P BP which is a function of a distribution voltage V DC .
[0043] The second power supply path V2 comprises:A second generator G2 configured to generate an alternating current by taking mechanical energy from the high pressure shaft HP andA second converter C2, associated with the second generator G2, to convert the generated alternating current into a second distribution intensity according to its setting, the second converter C2 generating a second power P HP which is a function of the distribution voltage V DC .
[0044] In this example, the first supply path V1 is associated with a power draw from a low pressure LP shaft while the second supply path V2 is associated with a power draw from a high pressure HP shaft. It goes without saying that the reverse is also possible.
[0045] In this example, the generators G1, G2 are preferably electrical machines capable of operating in a generator mode or motor mode. In a known manner, each electrical machine comprises a rotor secured to a rotating shaft (here a LP shaft or an HP shaft) and a stator comprising windings so as to generate three-phase alternating currents. Preferably, the speed and angular position of each generator G1, G2 are available. The structure and operation of such an electrical machine are known and will not be presented in further detail.
[0046] With reference to the, the electrical generation system 1 comprises an electrical distribution unit EDU which is electrically connected to the electrical network of the aircraft REA, to the electrical sources BAT or to the electrical loads LOAD.
[0047] Each converter C1, C2 provides a distribution voltage V DCto the EDU power distribution unit. Preferably, the EDU power distribution unit has a voltage bus.
[0048] In a known manner, each converter C1, C2 comprises a plurality of switches, in particular transistors, which make it possible to modify the electrical power generated and the mechanical power taken from each BP, HP shaft to adapt the distribution intensity according to requirements.
[0049] According to the invention, with reference to the, the electrical generation system 1 comprises a control device 2 configured to determine a first parameter setting P CONS1 for the first converter C1 and a second parameter setting P CONS2 for the second converter C2.
[0050] Preferably, each parameter setting instruction P CONS1 , P CONS2is in the form of a pulse width modulation (PWM) signal. Such a parameter setting P CONS1 , P CONS2 allows you to control the switching of the transistors of converters C1, C2.
[0051] With reference to the, the control device 2 comprises a first processing unit 22a configured to determine a first parameter setting P CONS1 for the first converter C1 from a first power setpoint P BP* . In addition, the control device 2 comprises a first regulation unit 21a configured to determine the first power setpoint P BP* depending on a distribution voltage setpoint V DC* and a measurement of the distribution voltage V DC The first regulation unit 21a is also configured to receive the generation setpoint P ECU , and determine from the latter the first power setpoint PBP* ; this last aspect being known to the person skilled in the art, it will not be presented subsequently.
[0052] The control device 2 also comprises a second processing unit 22b configured to determine a second parameter setting P CONS2 for the second converter C2 from a second power setpoint P HP* . In addition, the control device 2 comprises a second regulation unit 21b configured to determine the second power setpoint P HP* depending on a distribution voltage setpoint V DC* and a measurement of the distribution voltage V DC The second regulation unit 21b is also configured to receive the generation setpoint P ECU , and determine from the latter the second power setpoint P H P* ; this last aspect being known to the person skilled in the art, it will not be presented subsequently.
[0053] According to another embodiment, the electrical generation system 1 does not comprise a control device 2, and the first regulation unit 21a and the first processing unit 22a are combined in the first converter C1, while the second regulation unit 21b and the second processing unit 22b are combined in the second converter C2.
[0054] With reference to the, there is shown an embodiment of the first regulation unit 21a for determining the first power setpoint P BP* . The second control unit 21b has a similar architecture and will not be presented subsequently. For the sake of clarity and conciseness, only the first control unit 21a will be presented.
[0055] The first regulation unit 21a comprises a comparator 4 configured to determine a difference Δ between the distribution voltage setpoint V DC*and the measurement of the distribution voltage V DC . Preferably, the first regulation unit 21a takes into account the generation setpoint P ECU to determine the first power setpoint P BP* . For the sake of clarity and conciseness, taking into account the generation instruction P ECU will not be presented.
[0056] In this example, the first regulation unit 21a further comprises a correction module 5 which comprises a proportional corrector CP, having a proportional gain Kp, and an integral corrector CI having an integral gain Ki. Such correctors make it possible to carry out a regulation aimed at reducing the difference Δ to provide the first power setpoint P at the output. BP* . A proportional-integral type corrector is known to those skilled in the art and will not be presented later. It advantageously allows the static error to be cancelled.
[0057] In a known manner, the integral corrector CI is configured to determine a correction parameter that is determined between an initial time t0 and a current time tx. As the correction is carried out, the correction parameter includes a static error that increases. In this example, the integral corrector CI includes a reset module RAZ that is configured to reset the integral corrector CI. In particular, the reset module RAZ is configured to determine the correction with respect to a new initial time t0' that corresponds to the current time tx determined when the reset is activated. This advantageously makes it possible to stop the integral effect of the corrector CI in certain cases in order to control the dynamics of the integral, to limit overvoltages and undervoltages of the distribution voltage Vdc and to eliminate instabilities between the converters C1 and C2.
[0058] In this embodiment of the, the proportional corrector CP and the integral corrector CI are connected in series. According to another embodiment, shown in the, the proportional corrector CP and the integral corrector CI are connected in parallel. This other embodiment will be presented later.
[0059] It goes without saying that the correction module 5 could also include other correctors, in particular, a derivative corrector. According to one embodiment, the correction module 5 only includes an integral corrector CI, that is to say, the correction module 5 is devoid of a proportional corrector CP.
[0060] Still with reference to the, the first regulation unit 21a also comprises a divergence determination module 3 configured to determine a divergence indicator M3, in particular a Boolean, from the first power setpoint P BP* from correction module 5.
[0061] The divergence determination module 3 is connected to the reset module RAZ. The reset module RAZ is configured to activate depending on the divergence indicator M3. As illustrated in , the divergence determination module 3 is configured to determine the divergence indicator M3 from a gradient GP BP* of the first power instruction P BP*. En effet, le gradient GPBP*de la première consigne de puissance PBP*représente la variation de la première consigne de puissance PBP*et est représentatif du degré de correction et du risque de divergence.
[0062] With reference to the, the divergence determination module 3 is configured to determine the gradient GP BP* of the first power instruction P BP*et le comparer à un seuil de gradient prédéterminé S3.
[0063] With reference to the, according to a first embodiment, the divergence determination module 3 comprises a saturation block 30 and a comparison block 31.
[0064] In this first embodiment, the saturation block 30 determines a threshold value vS from the first power setpoint P BP*by limiting its variation compared to its previous values, according to a predetermined gradient threshold S3. This threshold value vS is then compared with the first power setpoint P BP* by the comparison block 31, determining the divergence indicator M3 as positive if the two values are different. Indeed, if the value of the power setpoint P BP*a été limitée par le bloc de saturation 30, cela signifie qu’elle a commencé à diverger et risque d’entrainer une instabilité. Dans cet exemple, l’indicateur de divergence M3 est égal à 1 en cas de divergence et est égal à 0 en l’absence de divergence.
[0065] According to another embodiment, shown in the, the divergence determination module 3 comprises a control block 33 and a gradient determination block 32.
[0066] Gradient determination block 32 explicitly determines the gradient GP BP * of the first power instruction P BP* by calculation. Control block 33 determines that the divergence indicator M3 is positive if the absolute value of the gradient GP BP* de la première consigne de puissance PBP*est supérieure à la valeur absolue du seuil de gradient prédéterminé S3.
[0067] Thus, the divergence indicator M3 makes it possible to indicate quickly and practically that the power setpoint P BP * is being changed too quickly and may lead to a risk of instability. The predetermined gradient threshold S3 is predetermined by calculation, statistically or by feedback.
[0068] A first embodiment of the first regulation unit 21a is shown having a correction module 5 having a cascaded architecture. In this example, a divergence is detected at the divergence instant t3. The first power setpoint P BP* then follows in this embodiment a mathematical law of the form:
[0069]
[0070] With :
[0071]
[0072] Where the initial time t0 corresponds to the initialization time of the regulation unit 21a, 21b, and the divergence time corresponds to the moment when the divergence indicator M3 indicated a divergence to the reset module RAZ. This advantageously allows the integral corrector CI to start operating again without taking into account what happened between the initial time t0 and the instant of divergence In other words, the full effect of the CI corrector is stopped immediately in order to stop the divergence as quickly as possible.
[0073] It is shown in a second embodiment of the first regulation unit 21a having a correction module 5 having a parallel architecture. The first power setpoint P BP* then follows in this embodiment a mathematical law of the form:
[0074]
[0075] With :
[0076]
[0077] Thanks to the invention, the two converters C1, C2 can be controlled independently, in a decentralized manner and without the need to set up a communication link. The reinitialization of the correction module 5, in particular of its integral corrector CI, during a divergence makes it possible to eliminate any risk of temporary instability in order to optimally generate energy for an aircraft.
[0078] In the prior art, the correction modules of the two correctors competed with each other. In the present case, the correction modules of the two correctors can be reset to zero at the same time without communication between them. The correction modules will start again with stable or even equal values in some cases by sharing control. This avoids instabilities. It also reduces voltage peaks by forcing the integral of the integral corrector CI to return to zero when the variation is too large. This prevents the integral from going into a strong overshoot before having to change direction. This aspect reduces the time to reach the desired correction.
Claims
Electrical generation method for supplying at least one electrical network of an aircraft (REA) from an electrical generation system, the aircraft comprising at least one aircraft turbomachine (T), the electrical system comprising two supply paths (V1, V2), each supply path (V1, V2) comprising an electrical converter (C1, C2) and an electrical generator (G1, G2) driven by the aircraft turbomachine (T), the electrical system comprising two regulation units (21a, 21b) associated respectively with each supply path (V1, V2), each regulation unit (21a, 21b) comprising a correction module (5) comprising an integral corrector (CI), the method comprising steps consisting of, for said correction module (5): Determining a power setpoint (P BP* , P HP* ), from a distribution voltage setpoint (V DC* ) and a measurement of the distribution voltage (V DC) of an electrical distribution unit (EDU) electrically connected to the aircraft electrical network (REA),Determine a divergence indicator (M3) from a gradient (GP BP* ) of the power setpoint (P BP* , P HP* ), andReset the integral corrector (CI) of the regulation unit (21a, 21b) of the supply channel (V1, V2) according to the divergence indicator (M3). Method according to claim 1, wherein the divergence indicator (M3) is determined from the comparison between the gradient (GP BP* ) of the power setpoint (PBP*, PHP*), and a predetermined gradient threshold (S3). Method according to claim 1, in which a limitation in variation over time is applied to the power setpoint (P BP* , P HP*) according to a predetermined gradient threshold (S3) in order to determine a threshold value (vS), and in which the divergence indicator (M3) is determined from the comparison between the power setpoint (P BP* , P HP* ), and the threshold value (vS). Control method according to one of claims 1 to 3, in which the regulation unit (21a, 21b) comprises a derivative corrector. Control method according to one of claims 1 to 4, in which the regulation unit (21a, 21b) comprises a proportional corrector (CP). Control method according to claim 5, in which the integral corrector (CI) and the proportional corrector (CP) are connected in cascade. Control method according to claim 5, in which the integral corrector (CI) and the proportional corrector (CP) are connected in series. Electrical generation system (1) for supplying power to at least one electrical network of an aircraft (REA) comprising at least one aircraft turbomachine (T), the electrical system comprising two supply paths (V1, V2), each supply path (V1, V2) comprising an electrical converter (C1, C2) and an electrical generator (G1, G2) driven by the aircraft turbomachine (T), the electrical system comprising a control device (2), the control device (2) comprising two regulation units (21a, 21b) respectively associated with each supply path (V1, V2), each regulation unit (21a, 21b) comprising a correction module (5) comprising an integral corrector (CI), each regulation unit (21a, 21b) being configured to:Determine a power setpoint (P BP* , P HP* ), from a distribution voltage setpoint (V DC* ) and a measurement of the distribution voltage (V DC) of an electrical distribution unit (EDU) electrically connected to the aircraft electrical network (REA),Determine a divergence indicator (M3) from a gradient (GP BP* ) of the power setpoint (P BP* , P HP* ),Reset the integral corrector (CI) of the regulation unit (21a, 21b) of the supply channel (V1, V2) according to the divergence indicator (M3). Electrically hybridized turbomachine comprising an electrical generation system (1) according to claim 8. Aircraft comprising at least one turbomachine according to claim 9.