Powering a hybrid-electric powered aircraft, using two TAGs

Abstract

Power supply architecture (1) comprising two gas turbines (2a, 2b), a propulsion system (5), and a non-propulsion system (6); the propulsion system comprising two first paths (5a, 5b), each associated with a separate gas turbine and each comprising a first AC generator (9), a first AC / DC converter (10), and a first battery (11), for powering propulsion equipment; the non-propulsion system comprising two second paths (6a, 6b), each associated with a separate gas turbine and each comprising a second AC generator (20), a second AC / DC converter (21), and a second battery (22), for powering non-propulsion equipment of the aircraft. Figure 1

Description

Title of the invention: Powering a hybrid-electric propulsion aircraft, using two TAGs

[0001] The invention relates to the field of electrical power supply for propulsion and non-propulsion equipment of hybrid-electric propulsion aircraft.

[0002] BACKGROUND OF THE INVENTION

[0003] 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 types of aircraft and to those in circulation requiring the implementation of technological solutions in order to make them compliant with current regulations. Civil aviation has been mobilizing for several years now to make a contribution to the fight against climate change. 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. Consequently, the Applicant is constantly working to reduce its negative climate impact by using methods and operating virtuous development and manufacturing processes and minimizing greenhouse gas emissions to the minimum possible to reduce the environmental footprint of its activity.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 ensure propulsion, and, as an essential complement to technological progress, aeronautical biofuels.

[0004] More and more aircraft manufacturers are thus offering architectures for hybrid-electric propulsion aircraft. Indeed, these architectures seem promising for reducing the carbon footprint of aircraft, particularly on "commuter" or regional aircraft with low transport capacity (typically less than 30 passengers).

[0005] Electric propulsion motors require high power to operate, for example of the order of 100 kW to 250 kW, under a high voltage, typically of the order of 800 Vdc.

[0006] Aircraft, in which an AC power network is integrated, generally carry a total power capable of supplying systems requiring powers between 50 kW and 500 kW (or even 1 MW), while low voltage DC (LV) networks have more limited on-board powers and less than 100 kW. DC networks are conventionally designed to operate at a voltage of 28 VDC, and are reserved for low powers. To date, there are no, or practically no, high voltage DC networks. As a result, there are no components capable of operating under high DC voltage and at sufficiently high powers that would meet the needs of propulsion networks.

[0007] It is therefore necessary to design new architectures to generate and transport the direct voltage and direct power required to power the aircraft's propulsion equipment. This is referred to as a "propulsion power supply network". Propulsion equipment includes, in particular, the aircraft's electric propulsion motors.

[0008] It is also necessary to design and integrate into the aircraft the power supply network for non-propulsive equipment (here we speak of the “non-propulsive power supply network”).

[0009] However, in most of the architectures envisaged today by aircraft manufacturers for electrically powered aircraft, whether hybrid or powered only by batteries, the non-propulsive power supply network is generally powered by converters which take their energy from the propulsive power supply network.

[0010] This solution, although natural for those skilled in the art, brings many constraints.

[0011] The power sources of the power supply network must therefore also carry the energy necessary for the operation of non-propulsive equipment. The additional mass (particularly when it comes to batteries) induced by this consumption balance of non-propulsive loads is significant, although often neglected by aircraft manufacturers in their initial analyses.

[0012] The constraints of non-propagation of failure from the propulsion supply network to the non-propulsion supply network (or vice versa) have a very strong impact on the design of converters.

[0013] Network quality constraints (voltage variation, harmonic content, etc.) are in fact generally higher on non-propulsion networks than on propulsion networks. This requires a high level of filtering on these converters, which tends to make them heavier.

[0014] Furthermore, the maturity of these converters is still low with regard to their capacity to be integrated into an aircraft.

[0015] In addition, the relatively high powers of non-propulsive networks (typically of the order of 100 kW to 150 kW) encourage suppliers to offer liquid-cooled converters in order to reduce mass and volume. This therefore implies the implementation of a new system, dedicated to the cooling of this equipment, which is not only expensive (to design, to manufacture) but is also heavy and bulky.

[0016] SUBJECT OF THE INVENTION

[0017] The subject of the invention is an electrical power supply architecture for aircraft: - allowing operation in hybrid mode; - reducing the constraints of oversizing the equipment of the propulsion supply network; - limiting any propagation of failure from the propulsion supply network to the non-propulsion supply network; - having reduced cost, mass and size. Summary of the invention

[0018] With a view to achieving this goal, an electrical power supply architecture is proposed, intended to be integrated into a hybrid-electric propulsion aircraft, and comprising two gas turbines, a propulsive power supply network and a non-propulsive power supply network;

[0019] the propulsion supply network comprising two first paths each associated with a separate gas turbine and a separate set of propulsion equipment, each first path comprising:

[0020] - a first AC generator mechanically connected to the gas turbine associated with said first path, and arranged to produce a first alternating voltage from a mechanical supply energy produced by said gas turbine;

[0021] - at least one first AC / DC converter connected to the first AC generator;

[0022] - at least one first battery;

[0023] the at least one first AC / DC converter and the at least one first battery of each first channel being arranged to power the set of propulsion equipment associated with said first channel;

[0024] the non-propulsive supply network comprising two second paths each associated with a separate gas turbine, each second path comprising:

[0025] - a second AC generator mechanically connected to the gas turbine associated with said second path, and arranged to produce a second alternating voltage from the mechanical supply energy produced by said gas turbine;

[0026] - at least one second AC / DC converter connected to the second AC generator;

[0027] - at least one second battery;

[0028] the at least one second AC / DC converter and the at least one second battery being arranged to supply non-propulsion equipment of the aircraft.

[0029] For each gas turbine, the first path of the propulsion power supply network and the second path of the non-propulsion power supply network associated with said gas turbine therefore have no common electrical point. The first AC generator and the second AC generator of these paths, located upstream of said paths (turbine side), are mechanically connected to the same turbine (for example via a power gearbox and / or via an accessory gearbox connected to said turbine), so that the first path and the second path have no electrical connection between them.

[0030] It is therefore not necessary to oversize the sources of the propulsion power supply network, since the non-propulsion power supply network is powered by the gas turbines and by its own batteries.

[0031] Furthermore, the absence of an electrical connection between the propulsion supply network and the non-propulsion supply network makes it possible to limit the propagation of faults between these networks. It is therefore not necessary to oversize the protection means (filtering in particular) of the propulsion network to make it compatible with the requirements relating to the non-propulsion network (regulations such as MIL-STD-704, DO 160, etc.).

[0032] The invention is the result of technological research aimed at very significantly improving the performance of aircraft and, in this sense, contributes to reducing the environmental impact of aircraft.

[0033] An architecture as previously described is further proposed, each gas turbine comprising a low pressure body, the first AC generator of each first path being connected via a power gearbox to the low pressure body of the gas turbine associated with said first path.

[0034] An architecture as previously described is further proposed, the second AC generator of each second path also being connected via the power gearbox to the low pressure body of the gas turbine associated with said second path, each gas turbine further comprising a high pressure body, each second path further comprising a generator-starter connected via an accessory gearbox to the high pressure body of the gas turbine associated with said second path.

[0035] An architecture as previously described is further proposed, each gas turbine further comprising a high-pressure body, the second AC generator of each second path being connected via an accessory gearbox to the high-pressure body of the gas turbine associated with said second path, the at least one second AC / DC converter of each second path comprising a bidirectional converter arranged to produce a starting alternating voltage arranged to be applied to a port of the second AC generator to start said gas turbine.

[0036] An architecture as previously described is further proposed, in which each first channel comprises a first AC / DC converter and a first battery arranged to power first propulsion equipment of the set of propulsion equipment associated with said first channel, and another first AC / DC converter and another first battery arranged to power second propulsion equipment of the set of propulsion equipment associated with said first channel.

[0037] An architecture as previously described is further proposed, in which each second channel further comprises a DC / DC converter connected to the second AC / DC converter, the at least one second AC / DC converter producing a medium DC voltage to implement a medium voltage power supply network supplying certain non-propulsive equipment, the DC / DC converter producing a low DC voltage from the medium DC voltage to implement a low DC voltage power supply network supplying other non-propulsive equipment.

[0038] We further propose an architecture as previously described, in which each first path further comprises a dynamic air turbine using a propeller of an electric propulsion motor powered by said first path.

[0039] We further propose an aircraft in which an architecture as previously described is integrated.

[0040] A power supply method is further proposed using the architecture as previously described, comprising the step, when the aircraft is on the ground, of using a ground power unit to recharge the first batteries and the second batteries and to power the non-propulsion equipment.

[0041] A power supply method is further proposed as previously described, comprising the step, to implement an all-electric mode when the aircraft is in flight, of using only the first batteries to power the propulsion equipment sets and the second batteries to power the non-propulsion equipment.

[0042] A power supply method is further proposed as previously described, comprising the steps, for implementing a hybrid mode when the aircraft is in flight, of starting each gas turbine using electrical energy from the second path associated with said gas turbine to produce mechanical starting energy applied to the input of an accessory gearbox which is connected to a high-pressure body of said gas turbine, and of using the gas turbines to at least partially power the propulsion equipment assemblies and non-propulsive equipment.

[0043] The invention will be better understood in light of the following description of particular non-limiting embodiments of the invention. Brief description of the drawings

[0044] Reference will be made to the attached drawings, among which:

[0045] [Fig-1] [Fig.l] represents a power supply architecture according to a first embodiment of the invention;

[0046] [Fig.2] [Fig.2] represents a graph illustrating the charging and discharge of batteries for a short mission in “all electric” mode;

[0047] [Fig.3] [Fig.3] is a figure similar to [Fig.2], for a long mission in “hybrid” mode;

[0048] [Fig.4] [Fig.4] is a figure similar to [Fig.l], illustrating a phase in which the aircraft is on the ground with the ground power unit connected;

[0049] [Fig.5] [Fig.5] is a figure similar to [Fig.l], illustrating a phase in in which the aircraft is in “all electric” mode;

[0050] [Fig.6] [Fig.6] is a figure similar to [Fig.l], illustrating a phase of right gas turbine start in flight;

[0051] [Fig.7] [Fig.7] also illustrates the start-up phase of the right gas turbine in flight, according to a variant of [Fig.6];

[0052] [Fig.8] [Fig.8] is a figure similar to [Fig.l], illustrating a phase in which the aircraft is in “hybrid” mode;

[0053] [Fig.9] [Fig.9] represents a power supply architecture according to a second embodiment of the invention;

[0054] [Fig. 10] [Fig. 10] represents a power supply architecture according to a third embodiment of the invention. DETAILED DESCRIPTION OF THE INVENTION

[0055] With reference to [Fig.l], the electrical power supply architecture 1 according to a first embodiment of the invention is here integrated into an aircraft 0 with hybrid-electric propulsion.

[0056] The architecture firstly comprises two gas turbines 2a, 2b.

[0057] Each gas turbine 2a, 2b is here a double-body turbine comprising a first body and a second body. The first body is here a body called a “low pressure body” (or LP spool) and the second body is here a body called a “high pressure body” (or HP spool).

[0058] The architecture 1 further comprises, for each gas turbine 2a, 2b, a power gearbox 3 (PGB, for Power Gear Train) and an accessory gearbox 4 (AGB, for Accessory Gear Box).

[0059] The low pressure body of each gas turbine 2a, 2b is connected to the associated power gearbox 3. The high pressure body of each gas turbine 2a, 2b is connected to the associated accessory gearbox 4.

[0060] Architecture 1 comprises a propulsive power supply network 5 and a non-propulsive power supply network 6.

[0061] The propulsion power supply network 5 is intended to supply the propulsion equipment of the aircraft 0, which notably comprises electric propulsion motors 7 (used to propel the aircraft) and electrical components which produce the power supply currents supplied to the electric motors and which control said motors 7.

[0062] The non-propulsive power supply network 6 is intended to supply the non-propulsive equipment 8 of the aircraft 0. This equipment 8 includes the equipment of the environmental control system (ECS, for Environmental Control System), the wing de-icing system (EWIPS, for Electric Wing Ice Protection System), the landing gear system (L / G, for Landing Gear), the wheel braking system, essential loads (ESS loads) including essential avionics equipment, commercial loads, loads supplied with 28 VDC, flight controls, FADEC (for EU Authority Digital Engine Control) computers, etc.

[0063] The propulsion supply network 5 comprises two first paths 5a, 5b, each associated with a separate gas turbine 2a, 2b and with a separate set of propulsion equipment 7a, 7b.

[0064] Each first route 5 a, 5b comprises:

[0065] - a first AC generator 9 mechanically connected to the gas turbine 2a, 2b associated with said first path, and arranged to produce a first alternating voltage Val from a mechanical supply energy produced by said gas turbine 2a, 2b;

[0066] - at least one first AC / DC converter 10 connected to the first AC generator 9 ;

[0067] - at least one first battery 11.

[0068] The at least one first AC / DC converter 10 and the at least one first battery 11 of each first channel 5a, 5b are arranged to power the set of propulsion equipment 7a, 7b associated with said first channel 5a, 5b.

[0069] In each first channel 5a, 5b, the first AC generator 9 here generates an apparent power of 500 kVa.

[0070] In each first path 5a, 5b, the input of the first AC generator 9 is connected via the power gearbox 3 to the low pressure body of the gas turbine 2a, 2b associated with said first path 5a, 5b.

[0071] The output of the first AC generator 9 is connected to a busbar 12 (AC) to which a high alternating voltage (Val) is applied, here equal to 350 Vac, and on which a high alternating power circulates.

[0072] The term "busbar" is equivalent to the terms "bus bar" or "bus bar", and designates, according to the definition given by the International Electronic Commission, a low impedance conductor to which several electrical circuits can be connected at separate points.

[0073] Each first channel 5a, 5b further comprises first connection means 14 (comprising at least one connector of any type) to a battery charging device which produces an alternating charging voltage (high voltage). The charging device is for example integrated into the conventional ground power unit (GPU).

[0074] This alternating charging voltage is applied to the busbar 12.

[0075] The first battery 11 comprises a port connected to a DC / DC converter 15.

[0076] We note here that we will speak of “port” to designate the interface of a component to the bidirectional operation, which is therefore both an input and an output. We also note that certain components which are used here in unidirectional, and therefore for which we use the terms "input", "output", could very well be bidirectional components (and vice versa, in the event of modification of the architectures presented, covered by the invention).

[0077] The input of the first AC / DC converter 10 is connected to the busbar 12.

[0078] The first AC / DC converter 10 converts an input voltage of 350 Vac into an output voltage of 800 Vdc. The apparent power produced is 250 kVA.

[0079] The output of the first AC / DC converter 10 and a port of the DC / DC converter 15 are connected to a busbar 13 (HV DC, for High Voltage Direct Current) on which a high direct voltage is applied (here 800 Vdc) and on which a high direct power circulates.

[0080] Each first channel 5a, 5b further comprises a busbar 17 and a busbar 18, which are connected to the busbar 13.

[0081] In the first channel 5a, the motor 7al and the motor 7a2 are powered via the busbar 17 (HV). The motor 7a3 and the motor 7a4 are powered via the busbar 18 (HV).

[0082] In the first channel 5b, the motor 7b1 and the motor 7b2 are powered via the busbar 17 (HV). The motor 7b3 and the motor 7b4 are powered via the busbar 18 (HV).

[0083] In each first channel, the current drawn from the first AC / DC converter 10 via each busbar 17 or 18 is typically 500 A.

[0084] It is noted here that the motors 7al, 7a2, 7b3, 7b4 each drive a single propeller, while the motors 7a3 and 7a4 together drive the same propeller, and the motors 7b1 and 7b2 together drive the same propeller.

[0085] The non-propulsive supply network 6 comprises two second paths 6a, 6b each associated with a separate gas turbine 2a, 2b, each second path comprising:

[0086] - a second AC generator 20 mechanically connected to the associated gas turbine to said second channel, and arranged to produce a second alternating voltage Va2 from the mechanical supply energy produced by said gas turbine;

[0087] - at least one second AC / DC converter 21 connected to the second generator AC 20;

[0088] - at least one second battery 22.

[0089] The second AC / DC converter 21 and the second battery 22 are arranged to power the non-propulsive equipment 8 of the aircraft 0.

[0090] In each second channel 6a, 6b, the second AC generator 20 here generates an apparent power of 500 kVa.

[0091] Here, for each second path 6a, 6b, the second AC generator 20 of said second path 6a, 6b is also connected via the power gearbox 3 to the low pressure body of the gas turbine 2a, 2b associated with said second path.

[0092] Each second path 6a, 6b further comprises a generator-starter 23 connected via the accessory gearbox 4 to the high-pressure body of the gas turbine 2a, 2b associated with said second path.

[0093] The output of the second AC generator 20 is connected to a busbar 24 (Main AC) to which a high alternating voltage is applied and on which a high alternating power flows.

[0094] The network 6 further comprises connection means 25 (comprising at least one connector of any type) to the park group. The group produces an alternating voltage of 115 Vac / 400 Hz. This voltage is applied to the bubar 24.

[0095] The input of each second AC / DC converter 21 is connected to the associated busbar 24.

[0096] The two busbars 24 of the two second channels 6a, 6b are connected to each other.

[0097] The second channels 6a, 6b therefore implement a high-voltage power supply network alternating voltage.

[0098] The second AC / DC converter 21 converts a high alternating voltage into a low direct voltage (28 Vdc).

[0099] In each second channel 6a, 6b, the output of the second AC / DC converter 21 is connected to a busbar 26 (MAIN LVDC1, MAIN LVDC 2) to which a low DC voltage is applied and on which a low DC power flows.

[0100] Each second channel 6a, 6b also comprises an auxiliary busbar 27 (EMER EVDC), on which a low direct voltage is applied and on which a low direct power circulates, and which is connected to the busbar 26 of said second channel 6a, 6b.

[0101] The two busbars 27 of the two second channels 6a, 6b are connected to each other.

[0102] The second battery 22 (25 Ah) of each second channel 6a, 6b has a connected port to busbar 27 of said second track 6a, 6b.

[0103] The second channels 6a, 6b therefore implement a low-voltage DC power supply network.

[0104] All the non-propulsion equipment previously mentioned is powered via the two busbars 24 (equipment 8a), except the flight controls, the FADEC computers and the essential avionics equipment (equipment 8b), which are powered via the two busbars 26 and the two busbars 27.

[0105] The proposed architecture allows the aircraft to operate in both "all-electric" and "hybrid" mode. In all-electric mode, only the batteries are used. The non-propulsive power supply network carries its own energy, which means that converters do not need to be installed between the propulsive and non-propulsive networks.

[0106] It should be noted that the technologies used for the components mentioned can be arbitrary. For example, with regard to the pairs “first AC generator and first AC / DC converter” and “second AC generator and second AC / DC converter”, the only constraint on each pair is to be able to regulate the output voltage. The following solutions can therefore be considered:

[0107] - Permanent magnet machine (for the generator), and active rectifier (for the converter);

[0108] - Three-stage machine, and passive rectifier;

[0109] - Machine with controlled inductor and passive rectifier.

[0110] In all-electric mode, with reference to [Fig. 2], the aircraft is first parked. The aircraft's electrical system is powered up. The batteries are charged. When the batteries are fully charged, taxiing begins. The aircraft takes off, flies at its cruising altitude. Then, the descent begins. Following the descent, the aircraft lands, rolls to the parking area and then is stopped. The batteries are charged between times T1 and T2. The batteries discharge between times T2 and T7.

[0111] In hybrid mode, with reference to [Fig.3], the gas turbines start following the end of battery charging. The batteries discharge until the end of the climb (between times T3 and T5), then recharge in the cruise phase (from T5).

[0112] With reference to [Fig.4], when the aircraft is on the ground, the ground unit is connected to the connection means 14 and 25 to recharge the first batteries 11 and the second batteries 22, and to power all the non-propulsion equipment 8.

[0113] The recharging is carried out through the first AC / DC converters 10 and the second AC / DC converters 21. The electrical power flows according to the arrows F.

[0114] In Figures 4 to 8, the gray areas of the architecture are not active or not powered.

[0115] With reference to [Fig.5], in all-electric mode, when the aircraft is in flight, only the first batteries 11 are used to power the propulsion equipment 7, and the second batteries 22 are used to power the non-propulsion equipment 8.

[0116] The quantity of energy on board is that required for the mission, with reserves for diversions.

[0117] With reference to [Fig.6], we are interested in the in-flight start of the gas turbine 2b (while the gas turbine 2a has already started and is contributing to the power supply of the propulsion equipment assembly 7a). This is a hybrid mode.

[0118] During the start-up phase, the starter-generator 23 of the gas turbine 2b is in starter mode and is powered by the battery 22 of the second channel 6b. The propulsion equipment assembly 7b is powered by the battery 11 of the first channel 5b.

[0119] The non-propulsion equipment 8a, normally supplied by the first channel 5b, is switched off during the start-up phase.

[0120] With reference to [Fig.7], we are again interested in the in-flight start of the gas turbine 2b.

[0121] This time, however, during the start-up phase, the non-propulsion equipment 8a, normally powered by the first channel 5b, are not switched off but are powered by the busbar 24 (MAIN AC) on the opposite side, i.e. from the second channel 6a.

[0122] Note that the position of the contactor 40 in a gray area indicates that it is open. The state of the other contactors is not specified but is obvious to those skilled in the art.

[0123] With reference to [Fig.8], when the gas turbines 2a, 2b have started, they are used to at least partially power the propulsion equipment and the non-propulsion equipment.

[0124] The gas turbines 2a, 2b also recharge the first batteries and the second batteries.

[0125] The gas turbines 2a, 2b are therefore sized to provide the propulsive power corresponding to cruising, as well as the power necessary for the non-propulsive loads, with also a capacity to charge the batteries in flight (propulsive and non-propulsive).

[0126] The architecture of [Fig.l] allows for the implementation of weak hybridization. The power is therefore distributed via an HVDC propulsion power supply network, which comprises two independent paths, each path being associated with one of the gas turbines. Each path supplies half of the propulsion system. The number of engines The number of HV busbars and the number of HV busbars are dictated by the aircraft's propulsion architecture, and may therefore differ from those described here. Here we have a two HV busbar architecture per side with two propulsion motors per HV busbar.

[0127] Each HV busbar is powered by an HVDC network. The battery on each HVDC network, during phases with high power requirements, typically takeoff, can provide a slight additional power. It also stabilizes the voltage of the HV DC busbar on which it is mounted. When the power required by propulsion is lower, the battery can be recharged.

[0128] With reference to [Fig.9], the electrical power supply architecture 101 according to a second embodiment of the invention is integrated into an aircraft 100 and again comprises two gas turbines 102a, 102b, a propulsive power supply network 105 and a non-propulsive power supply network 106.

[0129] The non-propulsive power supply network 106 is similar to that of architecture 1 of [Fig.l]. In [Fig.9], "100" is added to the references of the elements which are identical to those of [Fig.l] and which are not mentioned again in the description.

[0130] The propulsion supply network 105 comprises two first paths 105a, 105b, each associated with a separate gas turbine 102a, 102b and with a separate set of propulsion equipment 107a, 107b.

[0131] This time, each first channel 105a, 105b comprises a first AC / DC converter 110a and a first battery 111a arranged to power first propulsion equipment of the set of propulsion equipment 107a associated with said first channel, and another first AC / DC converter 110b and another first battery 111b arranged to power second propulsion equipment of the set of propulsion equipment 107b associated with said first channel.

[0132] In each first channel 105a, 105b, the input of the first AC / DC converter 110a is connected to the busbar 112 which is itself connected to the output of the first AC generator 109. The input of the first AC / DC converter 110b is also connected to the busbar 112.

[0133] The output of the first AC / DC converter 110a and a port of the first battery 111a are connected to the busbar 117. The output of the first AC / DC converter 110b and a port of the first battery 111b are connected to the busbar 118.

[0134] In the first channel 105a, the first propulsion equipment powered by the first AC / DC converter 110a and the first battery 111a comprise the motors 107al and 107a2, which are connected to the busbar 117. The first propulsion equipment powered by the first AC / DC converter 110b and the first battery 111b comprise the motors 107a3 and 107a4, which are connected to the busbar 118.

[0135] In the second channel 105b, the first propulsion equipment powered by the first AC / DC converter 110a and first battery 111a comprise motors 107bl and 107b2, which are connected to busbar 117. First propulsion equipment powered by first AC / DC converter 110b and first battery 111b comprises motors 107b3 and 107b4, which are connected to busbar 118.

[0136] The architecture of [Fig.9] makes it possible to implement strong hybridization.

[0137] Power is distributed via an independent AC (Alternative Current) network per TAG. Each network supplies power to half of the propulsion system. The number of propulsion motors per HV bar and the number of HV bars are dictated by the aircraft's propulsion architecture. Here we have an architecture with two HV bars per side with two propulsion motors per bar.

[0138] Each HV bar is powered by an AC network via power electronics. During phases requiring maximum propulsion power, the battery on each bar provides power and defines the voltage on the bar. The additional power is provided by the generator via the power electronics which adapts the supplied voltage to that of the battery.

[0139] When the generator alone can provide more than the total propulsion power on its side, the excess power is used to recharge the battery.

[0140] With reference to [Fig. 10], the electrical power supply architecture 201 according to a third embodiment of the invention, integrated in an aircraft 200, again comprises two gas turbines 202a, 202b, a propulsive power supply network 205 and a non-propulsive power supply network 206.

[0141] The propulsion supply network 205 is similar to that of [Fig. 9], except that each first channel 205a, 205b further comprises a dynamic air turbine 230 (RAT, for Ram Air Turbin). In [Fig. 10], we add "100" to the references of the elements which are identical to those of [Fig. 9] and which are not mentioned again in the description, and 200 to those of [Fig. 1].

[0142] In each first channel 205a, 205b, the dynamic air turbine 230 is integrated into an electric propulsion motor: motor 207al for the first channel 205a and motor 207b4 for the first channel 205b.

[0143] Each turbine 230 uses the propeller 231 of the motor 207al, 207b4 in which it is integrated. Each motor 207a1, 207b4 further comprises a generator 232, here of the PMG type (Permanent Magnet Generator, i.e. a permanent magnet synchronous machine), the rotor of which is connected to the propeller 231, to produce electrical energy. Each motor 207al, 207b4 further comprises a clutch and disengagement system (freewheel for example) to disconnect the generator 232 from the motor when the latter is electrically powered (by a battery or a gas turbine).

[0144] The non-propulsive supply network 206 again comprises a second path 206a and a second track 206b.

[0145] This time, in each second path 206a, 206b, the second AC generator 220 is connected via the accessory gearbox 204 to the high pressure body of the gas turbine associated with said second path 206a, 206b.

[0146] The second AC generator 220 is a generator that includes a port mechanically connected to the accessory gearbox 204 and a port connected to a busbar 224 (transfer bus), to which a high AC voltage is applied and to which a high AC power flows. The two busbars 224 are connected to each other.

[0147] The network 206 further comprises connection means 225 to the park group, by means of which the park group applies the recharging voltage to the two busbars 224.

[0148] Each second channel 206a, 206b further comprises a second AC / DC converter 221 and a second battery 222.

[0149] In each second channel 206a, 206b, the second AC / DC converter 221 is bidirectional (it can produce a direct voltage from an alternating voltage, and vice versa). It comprises a port connected to the busbar 224 and a port connected to a busbar 235 (MAIN MVDC). The second battery 222 has an output connected to the busbar 235. The second AC / DC converter 221 converts a high alternating voltage into a medium direct voltage, and vice versa.

[0150] This medium direct voltage (270 Vdc or 540 Vdc for example) is applied to the busbar 235, and a medium direct power flows on the busbar 235.

[0151] The network 206 therefore implements a medium voltage DC power supply network.

[0152] All the non-propulsion equipment previously mentioned is powered via the two busbars 235, and therefore by the medium voltage DC power supply network, except for the flight controls, the FADEC computers and the essential avionics equipment.

[0153] Each second channel 206a, 206b further comprises a bidirectional DC / DC converter 236 having a port connected to the busbar 235. The DC / DC converter 236 converts a medium DC voltage into a low DC voltage, and vice versa.

[0154] Each second channel 206a, 206b includes a busbar 226 (MAIN LVDC1, MAIN LVDC 2), an auxiliary busbar 227 (EMER LVDC) connected to the busbar 226, and a third battery 238 having a port connected to the busbar 227.

[0155] The two busbars 227 are connected to each other.

[0156] In each second channel 206a, 206b, the DC / DC converter 236 has a port connected to the busbar 226.

[0157] The second channels 206a, 206b therefore implement a power supply network in low direct voltage.

[0158] The flight controls, FADEC computers and essential avionics equipment (208b) are powered via busbars 226 and busbars 227 and therefore by the low voltage DC power supply network.

[0159] It can be seen that, in this embodiment, an AC generator has been removed per second channel 206a, 206b of the non-propulsion power supply network 206. There is no longer a starter-generator dedicated solely to this function.

[0160] The gas turbines 202a, 202b are started via the medium voltage DC power supply network of the non-propulsion power supply network. In each second channel 206a, 206b, the second AC / DC converter 221 (bidirectional) generates from a medium voltage DC a starting voltage (high voltage AC) which is applied to a port of the second AC generator 220 to start the gas turbine 2a, 2b associated with said second channel 206a, 206b via the accessory gearbox 4 (and the bus 224). It is therefore possible to use gas turbines requiring a higher starting torque.

[0161] This solution can also be used with the two previous architectures.

[0162] This architecture 201 also provides a complementary function in the end emergency, carried out today on aircraft by the addition of a dynamic air turbine.

[0163] Conventionally, for aircraft with fly-by-wire controls, the CS-25 certification specifications require the implementation of a function to ensure that an electrical source is maintained at 109 regardless of the failure affecting the aircraft, including engine shutdown. This function is conventionally provided by the deployment of ram air turbines.

[0164] This function, which is mandatory for aircraft with electric flight controls certified under CS-25, could also be necessary on aircraft with mechanical flight controls if these integrate more autonomous piloting modes.

[0165] Here, two of the four LVDC networks are powered via generators each driven by an electric propulsion motor. In the event of loss of the gas turbines 2a, 2b and if the first batteries 211 are discharged, the two engines 207a1, 207b4 are no longer powered but nevertheless continue to turn in windmilling mode and provide power to the generators to power the emergency functions. The aircraft can therefore glide while being piloted via the electric flight controls powered by the dynamic air turbines, which allows the aircraft to be saved.

[0166] [Fig. 10] therefore illustrates an evolution of the architecture in which two of the low-voltage DC power supply networks use electrical energy generated by two generators not directly driven by the gas turbines, but by the propulsion systems. This architecture makes it possible to have four networks completely independent low voltage, and two networks usable in emergency mode in the event of loss of both gas turbines.

[0167] Each small generator is mounted on the shaft between a propulsion engine and its propeller. It can be decoupled, if the function is necessary, in the event of engine failure via a clutch system, a freewheel.

[0168] It can also be driven via a gear system instead of being mounted directly on the shaft.

[0169] The constituent principles of the architecture according to the different embodiments are as follows:

[0170] - a total electrical separation between the propulsion network and the non-propulsion network;

[0171] - controlling battery charging while guaranteeing network stability electric for the propulsion system;

[0172] - an optimization of the masses according to the level of hybridization;

[0173] - the generation of 4 independent LVDC (Low Voltage Direct Current) networks in normal flight configuration.

[0174] The architecture therefore allows:

[0175] - to minimize failure cases and ensure better network availability low voltage;

[0176] - to ensure the stability of high voltage networks regardless of the level of hybridization while limiting the mass and number of components on the network;

[0177] - to cover failure cases thanks to possible reconfigurations;

[0178] - to use “classic” generators commonly used for systems ATA24 in civil aviation, and therefore conventional loads.

[0179] The proposed architecture therefore addresses the following problems:

[0180] - reduce the oversizing constraints of propulsion network equipment having to carry non-propulsive functions (subject to regulations such as MIL-STD-704, DO 160, etc.);

[0181] - limit any propagation of failure from the propulsion power supply network to the network non-propulsive power supply (and vice versa: no more impact of a short circuit of a non-propulsive load on the propulsion network);

[0182] - eliminate unwanted injections of HVDC voltage into MVDC networks and LVDC;

[0183] - allow operation in hybrid mode;

[0184] - start the gas turbines in all ground and flight phases;

[0185] - recharge the batteries in flight;

[0186] - manage cases of dimensioning failures;

[0187] - provide 3 or 4 independent low voltage power supplies to the computers housing critical functions.

[0188] The architecture also offers an advantage in terms of mass balance, compared to converter-based architectures. Indeed, generators have a higher power density than converters.

[0189] Of course, the invention is not limited to the embodiments described but encompasses any variant falling within the scope of the invention as defined by the claims.

[0190] All numerical values ​​provided herein, and in particular the voltage, current, power values, are provided as examples and could be different.

[0191] The number of first channels and second channels could be different from that described here, as could the number of components per channel: generator, converter, battery, etc.

Claims

Claims

1. Electrical power supply architecture (1), intended to be integrated into a hybrid-electric propulsion aircraft, and comprising two gas turbines (2a, 2b), a propulsive power supply network (5) and a non-propulsive power supply network (6); the propulsive power supply network comprising two first paths (5a, 5b) each associated with a separate gas turbine and a separate set of propulsion equipment (7a, 7b), each first path comprising: - a first AC generator (9) mechanically connected to the gas turbine associated with said first path, and arranged to produce a first alternating voltage (Val) from a mechanical power supply energy produced by said gas turbine; - at least one first AC / DC converter (10) connected to the first AC generator; - at least one first battery (11);the at least one first AC / DC converter and the at least one first battery of each first channel being arranged to supply the set of propulsion equipment associated with said first channel; the non-propulsion power supply network comprising two second channels (6a, 6b) each associated with a separate gas turbine, each second channel comprising: - a second AC generator (20) mechanically connected to the gas turbine associated with said second channel, and arranged to produce a second alternating voltage (Va2) from the mechanical power supply energy produced by said gas turbine; - at least one second AC / DC converter (21) connected to the second AC generator; - at least one second battery (22); the at least one second AC / DC converter and the at least one second battery being arranged to supply non-propulsion equipment (8) of the aircraft.;

2. Architecture according to claim 1, each gas turbine comprising a low pressure spool, the first AC generator of each first path being connected via a power gearbox (3) to the low pressure spool of the gas turbine associated with said first path.

3. Architecture according to claim 2, the second AC generator (20) of each second path (6a, 6b) also being connected via the power gearbox (3) to the low pressure body of the gas turbine associated with said second path, each gas turbine further comprising a high pressure body, each second path further comprising a generator-starter (23) connected via an accessory gearbox (4) to the high pressure body of the gas turbine associated with said second path.

4. Architecture according to claim 2, each gas turbine further comprising a high pressure spool, the second AC generator (220) of each second path being connected via an accessory gearbox (204) to the high pressure spool of the gas turbine associated with said second path, the at least one second AC / DC converter (221) of each second path comprising a bidirectional converter arranged to produce a starting AC voltage arranged to be applied to a port of the second AC generator to start said gas turbine.

5. Architecture according to one of the preceding claims, in which each first channel (105a, 105b) comprises a first AC / DC converter (110a) and a first battery (111a) arranged to power first propulsion equipment (107al, 107a2; 107bl, 107b2) of the set of propulsion equipment associated with said first channel, and another first AC / DC converter (110b) and another first battery (111b) arranged to power second propulsion equipment (107a3, 107a4; 107b3, 107b4) of the set of propulsion equipment associated with said first channel.

6. Architecture according to one of the preceding claims, in which each second channel further comprises a DC / DC converter (236) connected to the second AC / DC converter (221), the at least one second AC / DC converter producing a medium DC voltage to implement a medium voltage power supply network supplying certain non-propulsive equipment (8a), the DC / DC converter (236) producing a low DC voltage from the medium DC voltage to implement a low DC voltage power supply network supplying other non-propulsive equipment (8b).

7. Architecture according to one of the preceding claims, in which each first path (205a, 205b) further comprises a dynamic air turbine (230) using a propeller (232) of an electric motor

8.

9.

10.

11. propulsive (207a 1, 207b4) powered by said first channel. Aircraft (0) in which an architecture according to one of the preceding claims is integrated. Power supply method using the architecture (1) according to one of claims 1 to 7, comprising the step, when the aircraft is on the ground, of using a ground power unit to recharge the first batteries and the second batteries and to power the non-propulsive equipment. Power supply method according to claim 9, comprising the step, to implement an all-electric mode when the aircraft is in flight, of using only the first batteries (11) to power the sets of propulsion equipment and the second batteries (22) to power the non-propulsive equipment. Power supply method according to one of claims 9 or 10, comprising the steps, to implement a hybrid mode when the aircraft is in flight, of starting each gas turbine (2a, 2b) using electrical energy from the second path associated with said gas turbine to produce mechanical starting energy applied to the input of an accessory gearbox which is connected to a high pressure body of said gas turbine, and of using the gas turbines to at least partially power the propulsion equipment assemblies and the non-propulsion equipment.

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