System and method for generating electrical power for aircraft following fault detection

Abstract

An electrical generation system (1) for supplying at least one aircraft electrical network (AAN) comprising converters (C1, C2). Each converter (C1, C2) is configured to detect an internal fault, switch from a nominal mode (M1) to a fault mode (M3) upon detection of an internal fault, communicate its operating mode (M1-M3) to at least one other converter (C1, C2), and switch directly from auxiliary regulation (RegA) to voltage regulation (RegU) upon receiving a fault mode (M3) from at least one other converter (C1, C2). Abstract figure: Figure 8

Description

Title of the invention: System and method for generating electrical power for an aircraft following fault detection. Technical field

[0001] The present invention relates to an electrical generation system for an aircraft and, more generally, an electrical hybridization system for an aircraft.

[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 various states. In particular, an ambitious standard applies both to new types of aircraft and to those already in operation, 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] This sustained 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 incorporating a high-power electrical generation system. This would 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 takes mechanical energy from the low-pressure shaft of the aircraft turbomachine to produce electrical energy which is distributed to an electrical power distribution unit.

[0006] To increase electrical power generation, with reference to [Fig. 1], an electrical power generation system 100 has been proposed, configured to extract mechanical energy from a low-pressure shaft BP and mechanical energy from a high-pressure shaft HP of an aircraft turbomachine T to supply an aircraft electrical network REA with a calibrated distribution voltage. In other words, the electrical power generation system 100 comprises at least two power supply channels, here, one LP channel and one HP channel. The 100 electrical generation system can also be connected to BAT electrical sources or LO AD electrical loads, for example, propulsion motors.

[0007] In practice, the electrical generation system 100 is configured to receive an operating command (PECu) from a turbomachine ECU (Engine Control Unit) that knows the status of each electrical source as well as the electrical requirements. This operating command (PECu) makes it possible to determine, for example, the amount of electrical power to be generated, the mechanical power draw from each shaft, etc. In other words, the operating command (PECU) makes it possible to determine the hybridization strategy used. Furthermore, the operating command (PECu) makes it possible to modify the configuration of the electrical generation system 100 in the event of a fault, as will be explained later.

[0008] With reference to [Fig. 2], the electrical generation system 100 comprises at least two generators Gl, G2 (electrical sources) connected respectively to the low-pressure shaft BP and the high-pressure shaft HP of the turbomachine T. The electrical generation system 100 further comprises two converters Cl, C2, in particular inverters, which are respectively associated with the two generators Gl, G2. Each generator Gl, G2 generates an alternating current which is then rectified by its converter Cl, C2 to provide a distribution voltage VDC to an electrical distribution unit EDU, which is electrically connected to the aircraft's electrical network REA, to the electrical sources BAT, or to the electrical loads LO AD. The converters Cl, C2 are connected to the electrical distribution unit EDU by power cables H1, H2.

[0009] This example presents an application related to electrical generation, but the invention applies more generally to the field of hybridization in which an electrical machine performs, on the one hand, a generator function to draw mechanical power from the low-pressure shaft BP or the high-pressure shaft HP and, on the other hand, a motor function to inject mechanical power onto the low-pressure shaft BP or the high-pressure shaft HP. For a motor function, each converter C1, C2 can also convert the DC voltage VDC to supply AC current to the two electrical machines G1, G2 respectively in order to inject power.

[0010] For the sake of clarity and conciseness, only the generator function is presented. For a motor function, the ECU provides a PECu operating command that determines, for example, the mechanical power injection on each shaft, etc. The hybrid system is bidirectional to allow for both electrical power generation and power injection. mechanical. The ECU supervisory computer allows for general supervision by determining an operating setpoint PECu which is a function of the availability and capacity of the electrical sources but also of the needs of the electrical loads.

[0011] As is known, each converter Cl, C2 comprises a plurality of switches, in particular power transistors, which allow modification of the electrical power generated and the electrical power drawn by each generator Gl, G2 on each shaft BP, HP. With reference to [Fig. 2], the operating instruction PECu includes parameterization instructions Pconsi, Pcons2 for the converters Cl, C2 in order to obtain a distribution voltage VDC that is suitable for the electrical distribution unit EDU.

[0012] In a known manner, each converter Cl, C2 is configured to receive parameterization instructions Pconsi, Pcons2 of several types: • A voltage regulation setpoint RegU configured to control the converter Cl, C2 to a distribution voltage setpoint VDC*, • An auxiliary control setpoint RegA configured to control the converter Cl, C2 to a power setpoint or a torque setpoint of the aircraft turbomachine T.

[0013] Preferably, the distribution voltage setpoint VDC * is predetermined and known to each converter Cl, C2.

[0014] The operating setpoint PECu determines the type of regulation of each converter Cl, C2 by determining the parameterization setpoints Pconsi, Pcons2-

[0015] In practice, the ECU monitoring computer is connected to each converter Cl, C2 by one or more communication cables (point-to-point or multi-subscriber link) to communicate the parameterization instructions Pconsi, PcoNS2, but also to obtain data or measurements necessary for monitoring. Such communication cables, particularly of the CAN type, allow communication approximately every 15 ms, which is slow.

[0016] As previously stated, the ECU also allows the configuration of the electrical generation system 100 to be modified in the event of a fault. To this end, the ECU measures currents and voltages in the electrical generation system 100 in order to detect a fault, in particular, a short circuit in a control device 200, a converter Cl, C2, or a power cable Hl, H2. As is known, converters Cl, C2 periodically send their operating mode to the ECU.

[0017] The electrical generation system 100 further includes a plurality of switches for isolating one or more devices. The ECU (Electrical Control Unit) specifically controls the switches to reconfigure the electrical generation system 100 in order to electrically isolate a supply channel VI, V2 in the event of a fault. Thus, the ECU acts as a centralized supervisor, firstly determining the location and nature of the fault and, secondly, controlling the optimal configuration for isolating the fault.

[0018] One drawback is that such an ECU monitoring computer is relatively slow, on the order of 15 ms. In practice, the reconfiguration time, which allows the ECU monitoring computer to determine a fault and command the reconfiguration, is longer than the maximum permissible interruption time of the electrical generation system 100. Indeed, the generation system 100 must not be interrupted for too long, especially when it is supplying electric propulsion motors. An immediate solution would be to use an ECU monitoring computer with protocols allowing higher-speed communication and greater computing power in order to determine faults and the required reconfiguration more quickly. Such an ECU monitoring computer is expensive and requires extensive modification of the electrical generation system 100, which presents a disadvantage.

[0019] Furthermore, when a first converter Cl detects an internal fault, it switches from a nominal mode to a fault mode in which the first converter Cl is no longer active. To become active again, the first converter Cl must undergo extensive maintenance, particularly upon the aircraft's return to the ground. In practice, when the internal fault of the first converter Cl occurs, it affects the entire electrical generation system 100, and the second converter C2 also detects a fault and switches from a nominal mode to a safety mode in which the second converter C2 limits its operation (degraded operation).

[0020] One of the objectives of the present invention is to enable the rapid reconfiguration of an electrical generation system without resorting to an advanced supervisory control computer. PRESENTATION OF THE INVENTION

[0021] The invention relates to an electrical generation system for supplying at least one electrical network of an aircraft, hereinafter referred to as the aircraft network, the aircraft comprising at least one aircraft turbomachine including a low-pressure shaft and a shaft high pressure configured to be driven in rotation, the electrical generation system comprising at least: • A first supply route comprising: • A first generator configured to generate alternating current by drawing mechanical energy from one of the low-pressure and high-pressure shafts, • A first converter, connected to the first generator to power the aircraft network via at least one first power cable, • A second power supply route comprising: • A second generator configured to generate alternating current by drawing mechanical energy from the other of the low-pressure and high-pressure shafts, • A second converter, connected to the second generator to power the aircraft network via at least one second power cable, • the electrical generation system being configured to receive a first parameter setting for the first converter and a second parameter setting for the second converter, each parameter setting being either a voltage regulation setting to control the converter to a distribution voltage setting or an auxiliary regulation setting, at least one of the parameter settings being a voltage regulation setting.

[0022] The electrical generation system is remarkable in that each converter is configured to: • detect an internal defect, • switch from a nominal mode to a fault mode in the event of an internal fault detection, • communicate its operating mode to the other converter, and • switch directly from auxiliary regulation to voltage regulation upon receiving a failure mode from at least one other converter.

[0023] Advantageously, a voltage-regulating converter ensures the quality of the distribution voltage. An auxiliary voltage-regulating converter assists the aircraft network in maintaining the distribution voltage. This allows it to meet load requirements, for example, from propulsion engines or a temporary overload of the aircraft network.

[0024] Thanks to the invention, the electrical generation system can reconfigure itself autonomously without the supervisory computer. Thus, a converter in auxiliary regulation can automatically switch to voltage regulation in the event of a failure of another converter, in particular, a voltage regulation converter.

[0025] This allows for a highly responsive system and avoids excessively long interruptions in power generation, which could impact the aircraft's flight. Advantageously, the converters communicate directly or indirectly via a power generation system control device and are configured to directly change their regulation mode. A standard supervisory computer with conventional computing resources can thus be retained to manage overall monitoring during flight. Fault management is handled locally by the converters themselves and the control device. Thanks to the invention, any degradation of the distribution voltage over time, which could lead to fault propagation, is advantageously avoided. The power generation system is therefore more reliable and robust.

[0026] Preferably, the electrical generation system includes a control device connected to each converter by at least one communication cable so as to know the state of each converter but also data from each converter (input / output current, input / output voltage, etc.).

[0027] The control device is connected to a set of switches so as to electrically isolate each converter.

[0028] Preferably, the communication cable is a discrete signal communication cable.

[0029] The control device is configured to electrically isolate the converter exhibiting the fault mode. Thus, the control device makes it possible to contain the fault related to the converter exhibiting the fault mode.

[0030] Preferably, each converter is configured to switch directly from auxiliary regulation to voltage regulation upon receiving a fault mode from at least one other converter and when the converter experiencing the fault mode has been electrically isolated. Thus, any switchover is carried out in a safe manner.

[0031] The control device advantageously replaces a supervisory computer for changing the type of regulation in order to respond to a fault while remaining highly responsive. The control device only has a local view compared to a supervisory computer.

[0032] According to one aspect, the converters are directly connected to each other by at least one communication cable, preferably having a confirmation time of less than 5ms.

[0033] The invention has been presented for at least two supply paths, but it is understood that the number of paths could be greater.

[0034] According to one aspect, each converter is configured to directly communicate its operating mode to the control device, particularly when it enters fault mode. The control device is configured to electrically isolate the converter with the internal fault.

[0035] According to one aspect, the control device is connected to each converter by at least one communication cable, preferably having a confirmation time of less than 5ms.

[0036] Thus, electrical safety is ensured to allow degraded operation with a reduced number of equipment.

[0037] According to one aspect, the control device is configured to: • detect a cable fault in a power cable, and • electrically isolate the power cable with the cable fault.

[0038] Thus, a power cable can be reactively isolated without the need for a supervisory computer. According to a preferred aspect, the converter associated with the faulty power cable is also isolated.

[0039] According to one aspect, each converter being in a safety mode following the detection of the cable fault, the converter that is not associated with the power cable having the cable fault is configured to switch directly from auxiliary regulation to voltage regulation following the electrical isolation of the fault. Thus, the resumption of control is reactive.

[0040] Preferably, the converter, which is not associated with the power cable experiencing the cable fault, is configured to switch to nominal mode following fault resolution. A resolved fault is a fault that has been located and electrically isolated from the rest of the system but remains present in an isolated portion of the power generation system.

[0041] Thus, voltage regulation can also be implemented for a cable fault without using the supervisory computer.

[0042] According to one aspect, the electrical generation system comprising a plurality of electrical switches, the control device is configured to control the plurality of electrical switches in order to achieve electrical isolation of one or more pieces of equipment of the electrical generation system.

[0043] According to one aspect, each converter is configured to detect an internal fault by current and voltage measurements within the converter. Preferably, Each converter performs a functional test during which the distribution voltage and distribution current are compared to predetermined thresholds.

[0044] According to one aspect, each converter is configured to switch to a safety mode following the detection of a fault external to the converter.

[0045] According to one aspect, each converter being in a given regulation mode, auxiliary or voltage, each converter is configured to switch to a safety mode following the detection of a fault on said aircraft network, and to return to said given regulation mode following the electrical isolation of said fault.

[0046] According to one aspect, the electrical generation system includes an electrical distribution unit configured to be electrically connected to the aircraft's electrical network. The electrical distribution unit is powered by at least two converters. The electrical distribution unit is configured to detect a distribution fault by measuring current and / or voltage within the electrical distribution unit.

[0047] According to one aspect, each converter is configured to detect a distribution fault by current and / or voltage measurements in the electrical distribution unit.

[0048] Depending on one aspect, each converter is configured to: • perform a control test including a step of comparing a distribution voltage value to a predetermined minimum threshold and • switch directly from auxiliary regulation to voltage regulation after a successful control test, in particular, if the value of the distribution voltage is above the minimum threshold.

[0049] The invention also relates to an aircraft comprising an aircraft network and at least one aircraft turbomachine comprising a low-pressure shaft and a high-pressure shaft configured to be driven in rotation, at least one electrical generation system as previously described, supplying the aircraft network.

[0050] The invention also relates to a method of electrical generation for supplying at least one electrical network of an aircraft from an electrical generation system as described above, the aircraft comprising at least one aircraft turbomachine including a low-pressure shaft and a high-pressure shaft configured to be driven in rotation, a first converter being in voltage regulation, a second converter being in auxiliary regulation, the first converter and the second converter being in nominal mode, the method comprising steps during which: • The first converter detects an internal fault, • The first converter switches from nominal mode to a failure mode following upon detection of the internal fault, • the first converter communicates its failure mode to at least the second converter, and • the second converter switches directly from auxiliary regulation to voltage regulation upon receiving the fault mode of the first converter.

[0051] Preferably, the second converter switches directly from auxiliary regulation to voltage regulation upon receiving the fault mode of the first converter after the first converter is electrically isolated.

[0052] It goes without saying that the role of the converters could be reversed. The first converter could be in voltage regulation and the second converter could be in auxiliary regulation.

[0053] 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 execution of the steps of the process as described above. Preferably, the processor belongs to a converter. PRESENTATION OF THE FIGURES

[0054] 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.

[0055] Fig. 1 is a schematic representation of an electrical generation system drawing mechanical energy from an aircraft turbomachine.

[0056] Fig. 2 is a schematic representation of the electrical generation system with its generators, converters, an electrical distribution unit and a control device.

[0057] Fig. 3 is a schematic representation of an electrical generation system drawing mechanical energy from an aircraft turbomachine according to one embodiment of the invention.

[0058] Fig. 4 is a schematic representation of the electrical generation system with its converters, an electrical distribution unit and a control device according to one embodiment of the invention.

[0059] Fig. 5 is a schematic representation of the electrical generation system in the absence of a fault.

[0060] Fig. 6 is a schematic representation of the electrical generation system following the occurrence of an internal fault in a converter.

[0061] Fig. 7 is a schematic representation of the electrical generation system following electrical isolation.

[0062] Fig. 8 is a schematic representation of the electrical generation system after reconfiguration.

[0063] Fig. 9 is a schematic representation of the electrical generation system following the occurrence of a fault in the electrical distribution unit.

[0064] The [Fig. 10] is a schematic representation of the electrical generation system following the occurrence of an internal fault in a power cable.

[0065] It should be noted that the figures set out the invention in detail to implement the invention, said figures being of course able to serve to better define the invention where appropriate. DETAILED DESCRIPTION OF THE INVENTION

[0066] With reference to [Fig. 3], an electrical generation system 1 for an aircraft is shown. The aircraft comprises a turbomachine T including a low-pressure shaft BP and a high-pressure shaft HP. In this example, the turbomachine T includes a low-pressure compressor 71 and a low-pressure turbine 74 which are connected by the low-pressure shaft BP, and a high-pressure compressor 72 and a high-pressure turbine 73 which are connected by the high-pressure shaft HP.

[0067] The electrical generation system 1 is configured to draw mechanical energy from the low-pressure shaft BP and mechanical energy from the high-pressure shaft HP to supply an aircraft electrical network REA, hereinafter referred to as the aircraft network REA, with a calibrated voltage. The electrical generation system 1 can also be connected to electrical sources BAT or to electrical equipment to be powered LO AD, for example, electric propulsion motors.

[0068] In practice, as will be shown later, the electrical generation system 1 more generally allows for electrical hybridization to enable power to be drawn from or injected into the turbomachine T.

[0069] With reference to [Fig. 3], the electrical generation system 1 comprises two generators Gl, G2 connected respectively to the low-pressure shaft BP and the high-pressure shaft HP of the turbomachine T. The electrical generation system 1 comprises: • A first supply path VI comprising: • A first generator Gl configured to generate alternating current by drawing mechanical energy from the low-pressure shaft BP, • A first converter Cl, associated with the first generator Gl, to convert the generated alternating current into a first distribution intensity IDCi according to its parameters, • A second V2 power supply path comprising: • A second generator G2 configured to generate alternating current by drawing mechanical energy from the high-pressure shaft HP, • A second converter C2, associated with the second generator G2, to convert the generated alternating current into a second distribution current IDC 2 according to its parameter settings.

[0070] In this example, the generators G1 and G2 are preferably electrical machines capable of operating in generator mode or motor mode. As is known, each electrical machine comprises a rotor attached to a rotating shaft (here a low-pressure shaft or a high-pressure shaft) and a stator with windings designed to generate three-phase alternating currents. The structure and operation of such an electrical machine are known and will not be described in further detail.

[0071] With reference to [Fig. 3], the electrical generation system 1 comprises an electrical distribution unit EDU which is electrically connected to the aircraft network REA, the electrical sources BAT, or the electrical loads LO AD.

[0072] Each converter Cl, C2 provides a DC distribution voltage to the electrical distribution unit EDU. Preferably, the electrical distribution unit EDU includes a voltage bus.

[0073] Each converter Cl, C2 is connected to the electrical distribution unit EDU by one or more power cables Hl, H2, also called power harnesses, configured to transmit electrical power.

[0074] In a known manner, each converter Cl, C2 comprises a plurality of switching arms with switches, in particular transistors, which allow the electrical power generated and the mechanical power taken from each shaft BP, HP to be modified in order to adapt the distribution current IDCi, Idc2 according to the requirements.

[0075] According to the invention, with reference to [Fig.3], the electrical generation system 1 includes a control device 2 connected to each converter Cl, C2 so as to know the state of each converter but also data of each converter Cl, C2 (input / output current, input / output voltage, etc.).

[0076] The control device 2 is also connected to the electrical distribution unit EDU so as to know its state but also its data (incoming / outgoing current, input / output voltage, etc.).

[0077] With reference to [Fig. 4], the control device 2 is connected to a set of switches 7 so as to electrically isolate each converter Cl, C2 as well as the electrical distribution unit EDU. The control device 2 knows the state of each switch 7 so as to quickly determine whether a converter Cl, C2 is isolated or whether the electrical distribution unit EDU is isolated.

[0078] The electrical distribution unit EDU and the control device 2 together form a distribution and protection unit PDMU.

[0079] With reference to [Fig.3], the electrical generation system 1 is configured to receive an operating instruction PECu from a turbomachine ECU supervisory computer T. This operating instruction PECu includes a first parameterization instruction PConsi for the first converter Cl and a second parameterization instruction Pcons2 for the second converter C2.

[0080] Preferably, each parameter setting Pconsi, Pcons2 controls the switching of the transistors in the converters Cl, C2. Preferably, each converter Cl, C2 includes a control block configured to convert a parameter setting Pconsi, Pcons2 into a pulse-width modulation (PWM) signal. Such a control block is known to those skilled in the art. Each parameter setting Pconsi, Pcons2 is either a voltage regulation setpoint RegU to control the converter Cl, C2 to a distribution voltage setpoint VDC* or an auxiliary control setpoint RegA, for example, a power regulation setpoint or a torque regulation setpoint configured to control the converter Cl, C2 to a power / torque of the high-pressure shaft HP or the low-pressure shaft BP of the aircraft turbomachine T.

[0081] Preferably, among the set of converters Cl, C2, at least one of the converters C1,C2 is in voltage regulation to ensure a distribution voltage VDc* to the electrical distribution unit EDU.

[0082] As is known, the electrical generation system 1 can be interrupted in the event of a fault for a maximum interruption time of approximately 200 ms. For example, in the case of electric propulsion, this corresponds to the maximum time during which the electric propulsion motors do not provide thrust.

[0083] In this example, with reference to [Fig. 4], the converters Cl and C2 are directly connected to each other by a communication cable Q3, so as to allow direct and rapid communication without going through the ECU monitoring computer. Preferably, this communication cable Q3 is discrete signal (e.g., DSi, DSo) to benefit from responsive communication.

[0084] In this example, the converters Cl, C2 are each directly connected to the control device 2 by at least one communication cable Q1, Q2 so as to allow direct and rapid communication, without going through the ECU. Preferably, each communication cable Q1, Q2 is discrete signal (e.g., DSi, DSo) to benefit from reactive communication. Preferably, the converters Cl, C2 are not directly connected to each other by a communication cable Q3 but indirectly through the control device 2.

[0085] In this document, each Cl,C2 converter can be configured in at least two operating modes: a nominal mode M1 corresponding to normal, fault-free operation and a fault mode M3 corresponding to a shutdown of operation upon detection by the Cl,C2 converter itself of an internal fault. During such an internal fault, the Cl,C2 converter no longer switches and must be electrically isolated. The M3 fault mode corresponds to the detection of an internal fault, a short circuit, in the Cl,C2 converter, which cannot be repaired in flight and requires human intervention on the ground.

[0086] According to one aspect, each converter Cl, C2 can be configured according to a safety mode M2 ​​corresponding to limited operation with degraded performance. The safety mode M2 ​​is activated autonomously by a converter upon detection by the converter itself and / or the control device 2 of a minor fault, in particular, an external fault affecting said converter Cl, C2. The external fault may be a fault in a power cable between a converter and the distribution unit EDU, a fault in the distribution unit EDU, or a fault on the aircraft electrical network REA. The switching of converter Cl, C2 is temporarily stopped while said external fault is investigated. The fault mode M3 takes precedence over the safety mode M2 ​​in order to maintain a high level of safety.

[0087] With reference to [Fig. 4], the electrical generation system 1 comprises a plurality of electrical switches 7, in particular, between each converter C1, C2 and the electrical distribution unit EDU and between the electrical distribution unit EDU and the aircraft electrical network REA. As will be described in detail later, the control device 2 is configured to operate the plurality of electrical switches 7 in order to achieve electrical isolation of one or more pieces of equipment in the electrical generation system 1 based on the detection and location of electrical faults.

[0088] With reference to Figures 6 to 8, the invention is notable in that each converter Cl, C2 is configured to: • detect (step El) an internal DEFi fault, i.e. of the converter Cl, C2 concerned, • switch (step E2) from a nominal mode M1 to a fault mode M3 in case of detection of an internal fault DEFi, • communicate (step E3) its operating mode M1 or M3 to at least one other converter Cl, C2, and • switch E4 directly from an auxiliary regulation RegA to a voltage regulation RegU upon receiving a fault mode M3 from at least one other converter Cl, C2.

[0089] By internal DEFi default, we mean a major converter fault that cannot be repaired in flight.

[0090] Thus, in the event of a fault in one of the converters, the other converter(s) Cl, C2 can reconfigure themselves automatically and rapidly, without intervention from the ECU. This improves responsiveness for reconfiguration within the maximum interruption time limit. Furthermore, the propagation of a fault between converters Cl, C2, as in the prior art, is advantageously avoided. Advantageously, converters Cl, C2 have identical functions to allow for similar reconfiguration in the event of a fault in one of converters Cl, C2. The electrical generation system 1 is thus scalable to several supply channels VI, V2.

[0091] Internal defect of a converter

[0092] According to step E1, each converter C1,C2 is configured to detect an internal DEFi fault, in particular, an internal short-circuit fault. According to one aspect, each converter C1,C2 is configured to detect an internal DEFi fault by measuring its distribution currents and voltages.

[0093] To this end, each Cl, C2 converter is configured to perform a functional test. In this example, the functional test mainly comprises two comparison steps: • a step comparing the distribution voltage Vdc to a predetermined voltage threshold Vsl, for example, 450V. This involves determining whether the distribution voltage Vdc supplied by the power converter in question is lower than the threshold Vsl, Vdc < Vsl, which is an indicator of a short-circuit type failure (the voltage Vdc collapses) and • a step of comparing the distribution current Idc to a predetermined current threshold Isl, for example, 200A. This is to determine if the distribution current Idc supplied by the converter is too high, above a threshold Isl, Idc > Isl, which, combined with a collapsed voltage Vdc, indicates or confirms the presence of a short circuit.

[0094] Such an internal DEFi fault is a major fault, as it cannot be repaired in flight. The converter that detects such an internal DEFi fault is configured to switch from a nominal mode M1 to a failure mode M3 (step E2).

[0095] According to step E3, each converter Cl, C2 is configured to communicate its operating mode M1 or M3 to at least one other converter Cl, C2. According to a preferred aspect, each converter Cl, C2 is configured to directly communicate its operating mode M1 or M3 to the control device 2, in particular its fault mode M3. The control device 2 centralizes the states of the various elements of the power generation system 1. Each converter Cl, C2 thus reactively communicates its operating mode M1-M3 to the other equipment of the power generation system 1.

[0096] According to a preferred aspect, in a similar manner, each converter Cl, C2 is configured to communicate its operating mode M1-M3 directly to the ECU supervisory computer so that the latter performs global but slow supervision.

[0097] In the present case, in the event of an internal fault DEFi of the first converter Cl, the control device 2 allows the first converter Cl to be electrically isolated by controlling the switches 7 (switch 7 open in [Fig. 7]). Preferably, an electrical isolation confirmation is transmitted to each converter Cl, C2 by the control device 2 to ensure electrical safety.

[0098] According to step E4, the second converter C2 is configured to switch directly from an auxiliary regulation RegA to a voltage regulation RegU upon receiving a fault mode M3 from the first converter CL. Preferably, such a switch is only performed when the first faulty converter Cl has been electrically isolated.

[0099] When several converters Cl, C2 are used to power an aircraft electrical network REA, at least one converter Cl, C2 is in RegU voltage regulation mode to ensure network quality. If the network quality is satisfactory, one or more converters may switch to RegA auxiliary regulation mode following an instruction from the ECU supervisory computer. Thanks to the invention, in the event of a failure of a converter that was in RegU voltage regulation mode, at least one healthy converter will switch from RegA auxiliary regulation mode to RegU voltage regulation mode reactively and autonomously, after electrical isolation of the faulty converter by the control device 2.

[0100] The control device 2 manages the electrical isolation (control of the isolation switches 7) solely on the basis of discrete signal exchanges, allowing network quality to be restored in an optimal time. This switchover is performed autonomously by the second healthy converter C2, and reactive, that is to say quickly, in reaction to the exchange of discrete signals.

[0101] Preferably, before performing the E4 switching step, the second converter C2 performs a control test. The control test includes a step comparing the value of the distribution voltage Vdc to a predetermined minimum threshold. For example, the control test includes a step verifying that the value of the distribution voltage Vdc is not too low to resume voltage regulation RegU. In this example, it is verified that the amplitude of the distribution voltage Vdc is greater than a predetermined minimum threshold, for example, 200V.

[0102] Communication cables Q1, Q2, Q3, particularly those with discrete signals, enable fast communication, specifically with a maximum confirmation time of 5 ms. This ensures simple, fast, and robust reactivation of the distribution voltage control Vdc. Preferably, the discrete signals are redundant.

[0103] External fault

[0104] According to another aspect, with reference to [Fig.10], the control device 2 is configured to detect an external fault, such as a fault in a power cable between a converter and the EDU distribution unit, a fault in the distribution of the EDU distribution unit or a fault on the aircraft electrical network REA, on the basis of the data (incoming / outgoing current, input / output voltage, etc.) of the converters and the electrical distribution unit.

[0105] Cable fault DEFh

[0106] In particular, the control device 2 is configured to • Detect a DEFh cable fault in a power cable Hl, H2, • Electrically isolate the power cable Hl, H2 having the cable fault DEFh, in particular, by piloting switches 7.

[0107] Alternatively or cumulatively, the converter Cl, C2 connected to the power cable Hl, H2 can also detect a fault in the DEFh cable to inform the control device 2 and thus electrically isolate the power cable Hl, H2. To this end, the converter Cl, C2 receives information from the control device 2. In one example, the power cable Hl of the first channel VI is the one with the fault, but it goes without saying that it could be that of the second channel V2. The monitoring is identical for both channels VI, V2.

[0108] By way of example, the control device 2 and / or each converter Cl, C2 is configured to perform a functional test of a power cable Hl, H2. According to one aspect, the functional test is configured to analyze the incoming and outgoing current of a power cable Hl, H2. In particular, if the If the incoming and outgoing currents do not flow in the same direction (same sign), a DEFh cable fault is detected, specifically a short circuit. Alternatively, a DEFh cable fault can be detected if the difference between the incoming current in the power cable H1, H2 and the outgoing current in the power cable H1, H2 exceeds a predetermined threshold.

[0109] When a fault in cable DEFh is detected, the power cable concerned Hl, H2 is electrically isolated, in particular, by controlling the switches 7 by the control device 2. According to one aspect, the converter Cl, C2, associated with the faulty power cable Hl, H2 is also isolated.

[0110] Following a cable fault DEFh, each converter Cl, C2 is in a safety mode M2. Preferably, the converter Cl, C2 that is not associated with the power cable Hl, H2 experiencing the cable fault DEFh is configured to switch directly from auxiliary regulation RegA to voltage regulation RegU following electrical isolation of the fault. This ensures optimal power supply.

[0111] Preferably, the converter Cl, C2, which is not associated with the power cable Hl, H2 having the cable fault DEFh, is configured to switch to nominal mode Ml following the clarification of the fault.

[0112] Thus, electrical safety is ensured even in the event of a fault in a power cable Hl, H2.

[0113] Automatic reactivation of converter Cl, C2, which is not associated with the power cable Hl, H2 having the cable fault DEFh, can be achieved by verifying that the distribution voltage Vdc is above a voltage threshold. In this example, it is verified that the amplitude of the distribution voltage Vdc is above a predetermined minimum threshold, for example 200V. Furthermore, a difference is calculated between the value of the distribution voltage Vdc and the value of the distribution voltage Vdc filtered at 15 Hz, and then the evolution of this difference is monitored to ensure that it increases in order to resume voltage regulation RegU.

[0114] Aircraft electrical fault REA

[0115] In the event of a fault on the aircraft electrical network REA, the control device 2 and the converters Cl, C2 are not configured to detect and resolve the fault. The fault on the aircraft electrical network REA is an external fault, and each converter Cl, C2 switches to the M2 safety mode. Following resolution of the external fault by an external device (not shown), the automatic reactivation of the converters Cl, C2 is performed in a manner analogous to a DEFh cable fault as previously described. The converters Cl, C2 remain in the control mode that existed prior to the occurrence of the fault on the aircraft electrical network REA.

[0116] PDMU Fault

[0117] According to one aspect, with reference to [Fig.9], the electrical distribution unit EDU is configured to detect a distribution fault DEFd of the electrical distribution unit EDU by current and / or voltage measurements in the electrical distribution unit EDU.

[0118] By way of example, the control device 2 and / or the electrical distribution unit EDU is configured to perform a functional test of the electrical distribution unit EDU. In one aspect, the functional test is configured to compare the sum of the incoming currents to the sum of the outgoing currents of the electrical distribution unit EDU. In particular, with reference to [Fig. 9], if the difference between the sum of the incoming currents le and the sum of the outgoing currents Is is greater than a predetermined threshold, a distribution fault DEFd is detected.

[0119] When a DEFd distribution fault is detected, the EDU electrical distribution unit is electrically isolated and no further electrical generation is possible.

[0120] General example

[0121] An electrical generation process will be presented according to an example of implementation.

[0122] Such a generation process makes it possible to detect a fault, locate the fault in order to isolate it electrically, and then restore network quality, in particular by ensuring that at least one electrical converter Cl, C2 provides voltage regulation RegU for the electrical distribution unit EDU. This takeover of control is carried out autonomously and in a decentralized manner by the converters Cl, C2.

[0123] According to the invention, the generation method is configured to perform monitoring of internal faults of the converters Cl, C2 but also of external faults such as faults of the power cables Hl, H2, of the electrical distribution unit EDU or of the aircraft electrical network REA.

[0124] In this implementation example, with reference to [Fig. 5], the first converter Cl is in voltage regulation RegU while the second converter C2 is in auxiliary regulation RegA. Thus, it is the first converter Cl that ensures power quality by regulating the distribution voltage Vdc. Both the first converter Cl and the second converter C2 are in nominal mode ML

[0125] During the aircraft's flight, an internal short circuit occurs in the first converter Cl as illustrated in [Fig. 6]. The first converter Cl detects an internal fault DEFi by measuring currents and voltages during its functional test. Following the detection of the internal fault DEFi, as shown in [Fig. 7], the first converter Cl switches from the nominal mode Ml to the mode of failure M3 and directly communicates its failure mode M3 by a corresponding discrete signal transmitted to the second converter C2 via the communication cable Q3 as well as to the control device 2 via the communication cable Q1.

[0126] With reference to [Fig.7], upon receipt of this discrete signal indicating the fault mode M3 of the converter Cl, the control device 2 electrically isolates this converter Cl having the internal fault DEFi by controlling the various switches 7.

[0127] With reference to [Fig. 8], the second converter C2, which in the example is in nominal mode M1 and auxiliary regulation RegA, performs a control test to check if voltage regulation is possible, in particular by verifying that the value of the distribution voltage Vdc is not too low (compared to a threshold, for example). The control test performed by the second converter C2 includes the step of first ensuring that it has been informed by the control device 2 that the first converter Cl is properly electrically isolated.

[0128] If the conditions are met, the second converter C2 switches from auxiliary regulation RegA to voltage regulation RegU upon receipt of the discrete signal indicating a fault mode M3 of the first converter Cl. This switchover is direct, or autonomous, in that it is independent of the ECU monitoring computer, which ensures a high level of responsiveness.

[0129] The second converter C2 then provides voltage regulation RegU, which ensures the quality of the electrical network by regulating the distribution voltage Vdc.

[0130] Advantageously, after clarification of the fault, the ECU supervisory computer will then transmit a new parameter instruction Pcons2 to the second converter C2 in order to regain control.

[0131] With regard to external faults, as shown in [Fig. 9], in the event of a distribution fault DEFd in the electrical distribution unit EDU, the latter is isolated by the control device 2 by operating the switches 7. As shown in [Fig. 10], in the event of a cable fault DEFh in the power cable H1 between the first converter Cl and the electrical distribution unit EDU, the cable fault DEFh is isolated by the control device 2 by operating the switches 7 (fault clarified). The first converter Cl and the second converter C2 enter safety mode M2 ​​related to an external fault. If the second converter C2, which is not associated with the power cable H1 having the cable fault DEFh, is in auxiliary regulation RegA, the second converter C2 switches directly from auxiliary regulation RegA to voltage regulation RegU following electrical isolation of the fault.This allows for a reactive approach to ensuring the quality of the electrical network by regulating the distribution voltage (Vdc).

[0132] When the cable fault DEFh has been clarified and it is verified that the distribution voltage Vdc is above a predetermined threshold and that its increase is consistent with the previously described pattern, the second converter C2 returns to nominal mode M1 while the first converter Cl remains in safety mode M2. The ECU supervisory control unit will transmit new parameterization instructions Pcons1, Pcons2 in order to regain control.

[0133] In the event of a fault in the aircraft electrical network REA, typically short-circuit faults, the converters Cl, C2 are configured to switch to M2 safety mode because the fault is not internal to the converters Cl, C2. For example, the converters Cl, C2 can switch to M2 safety mode upon detection by the converters Cl, C2 or the EDU of an undervoltage or overcurrent.

[0134] As soon as the ECU has identified (located and isolated) the faulty (short-circuited) section of the network, converters Cl and C2 will autonomously reactivate their control. As previously described, a control test, previously shown for a DEFh cable fault, is performed before effective control is resumed. Converters Cl and C2 remain in the regulation mode they were in before the fault occurred on the aircraft electrical network REA.

[0135] Thus, the electrical generation system 1 is robust and can react quickly to any fault, which prevents the propagation of faults in all the equipment of the electrical generation system 1 which could lead to a shutdown of electrical generation.

Claims

1. Demands Electrical generation system (1) for supplying at least one electrical network of an aircraft, hereinafter referred to as the aircraft electrical network (AEN), the aircraft comprising at least one aircraft turbomachine (T) comprising a low-pressure shaft (LP) and a high-pressure shaft (HP) configured to be driven in rotation, the electrical generation system (1) comprising at least: A first supply path (VI) comprising: • A first generator (Gl) configured to generate alternating current by drawing mechanical energy from one of the low pressure (LP) and high pressure (HP) shafts, • A first converter (Cl), associated with the first generator (Gl) to supply the aircraft network (REA) via at least one first power cable (Hl), A second power supply path (V2) comprising: • A second generator (G2) configured to generate alternating current by drawing mechanical energy from the other of the low pressure (LP) and high pressure (HP) shafts, • A second converter (C2), associated with the second generator (G2) to supply the aircraft network (REA) via at least one second power cable (Hl), the electrical generation system (1) being configured to receive a first parameter setpoint (Pconsi) for the first converter (Cl) and a second parameter setpoint (PCons2) for the second converter (C2), each parameter setpoint (Pconsi, Pcons2) being either a voltage regulation setpoint (RegU) to control the converter (Cl, C2) to a distribution voltage setpoint (VDC*) or an auxiliary regulation setpoint (RegA), at least one of the parameter setpoints (Pconsi, Pcons2) being a voltage regulation setpoint (RegU), • Electrical generation system (1) characterized in that each converter (Cl, C2) is configured to: • detect an internal fault (DEFi), • switch from a nominal mode (M1) to a fault mode (M3) in case of detection of an internal fault (DEFi), • communicate its operating mode (M1,M3) to the other converter (Cl, C2), and • switch directly from an auxiliary regulation (RegA) to a voltage regulation (RegU) upon receipt of a fault mode (M3) from at least one other converter (Cl, C2).

2. Electrical generation system (1) according to claim 1, comprising a control device (2) connected to each converter (Cl, C2) by at least one communication cable (Q1, Q2) so as to know the state of each converter (Cl, C2) but also data of each converter (Cl, C2), the control device (2) is connected to a set of switches (7) so as to electrically isolate each converter (Cl, C2).

3. Electrical generation system (1) according to claim 2, wherein the communication cable (Q1, Q2) is a discrete signal communication cable.

4. Electrical generation system (1) according to any one of claims 2 to 3, wherein each converter (Cl, C2) is configured to directly communicate its operating mode (M1-M3) to the control device (2), the control device (2) being configured to electrically isolate the converter (Cl, C2) having the internal fault (DEFi).

5. Electrical generation system (1) according to any one of claims 1 to 4, wherein the control device (2) is configured to: • detect a cable fault (DEFh) of a power cable (Hl, H2), and • electrically isolate the power cable (Hl, H2) having the cable fault (DEFh).

6. Electrical generation system (1) according to claim 5, wherein each converter (Cl, C2) being in a safety mode (M2) following the detection of the cable fault (DEFh), the converter (Cl, C2), which is not associated with the power cable (Hl, H2) having the cable fault (DEFh), is configured to switch directly from auxiliary regulation (RegA) to voltage regulation (RegU) following electrical isolation of the fault.

7. Electrical generation system (1) according to any one of claims 1 to 6, comprising an electrical distribution unit (EDU) configured to be electrically connected to the aircraft electrical network (REA), the electrical distribution unit (EDU) being powered by at least two converters (Cl, C2), the electrical distribution unit (EDU) being configured to detect a distribution fault (DEFd) by current and / or voltage measurements in the electrical distribution unit (EDU).

8. Aircraft comprising an aircraft network (ASN) and at least one aircraft turbomachine (T) comprising a low pressure shaft (LP) and a high pressure shaft (HP) configured to be driven in rotation, at least one electrical generation system (1), according to any one of claims 1 to 7, supplying the aircraft network (ASN).

9. A method for generating electricity to supply at least one aircraft electrical network (AAN) from an electrical generation system (1) according to any one of claims 1 to 7, the aircraft comprising at least one aircraft turbomachine (T) including a low-pressure shaft (LP) and a high-pressure shaft (HP) configured to be driven in rotation, a first converter (Cl) being in voltage regulation (RegU), a second converter (C2) being in auxiliary regulation (RegA), the first converter (Cl) and the second converter (C2) being in nominal mode (M1), the method comprising steps in which: • the first converter (Cl) detects an internal fault (DEFi), • the first converter (Cl) switches from nominal mode (M1) to a fault mode (M3) following the detection of the internal fault (DEFi), • the first converter (Cl) communicates its fault mode (M3) to at least the second converter (C2),• The second converter (C2) switches directly from auxiliary regulation (RegA) to voltage regulation,

10. (RegU) upon receiving the fault mode (M3) of the first converter (Cl). A computer program-type product, comprising at least one sequence of instructions stored and readable by a processor and which, once read by that processor, causes the execution of the steps of the process of claim 9.

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