Aircraft with hybrid power source and with junction having a transistor for distribution and protection

Abstract

The invention relates to an aircraft comprising: - drive units, - at least one battery of the drive units, - at least one electricity generation source connected to each battery and comprising at least one electrical converter, and - a power supply control for controlling each electricity generation source as a function of the power requirements of the drive units and for treating each battery passively. Each electrical converter is connected to each battery via a particular junction (102) including two field effect transistors having a metal oxide gate (104, 106) connected in series and with opposite forward directions. Each junction (102) can operate exclusively in a unidirectional state in which the current flows from the electrical converter to the battery, a bidirectional state, and an off state.

Description

[0001] Description

[0002] Title: Aircraft with hybrid power source and distribution and protection transistor junction

[0003] The field of the invention relates to aircraft, and more particularly to electrically powered aircraft.

[0004] The aeronautics industry is currently undergoing numerous developments linked to environmental constraints, and in particular to the requirement for a gradual reduction in greenhouse gas emissions such as carbon dioxide (CO2). In this respect, the development of electrically powered aircraft appears to be a real step forward.

[0005] The classic architecture of an electric-powered aircraft incorporates at least one source of electrical generation arranged to power battery packs, which supply power to drive units as needed. For example, in the case of an electric vertical take-off and landing (eVTOL) aircraft, the batteries are combined with vertical drive units and horizontal drive units. The multiplication of batteries makes it possible, in particular, to meet safety standards requiring component redundancy to ensure continued safe flight and landing.

[0006] In particular, in the case of a hybrid power aircraft, the electrical generation source comprises a fuel-fired electrical power generator, for example a turbine engine or a fuel cell.

[0007] The battery power circuit can be configured so that the batteries are connected to each other in parallel. Such a circuit is then equipped with a separation protection system to isolate the batteries from each other in the event of a fault, particularly a short circuit. Activation of such a protection system, however, results in a significant loss of power due to the isolation of one of the batteries.

[0008] One possible solution to prevent the spread of a failure to all batteries while limiting the potential loss of power is to directly separate the batteries and organize the power supply circuit accordingly. However, such a separation principle is thwarted in the case of a hybrid energy source aircraft. Indeed, a hybrid energy source aircraft has the particularity that the batteries are generally more numerous than the electrical generation sources for reasons of redundancy, which implies connecting the batteries together via shared electrical generation sources. Such an interconnection constitutes a common point of failure between batteries powered by the same electrical generation source.

[0009] Furthermore, each battery is generally coupled to an electrical converter, for example an inverter or a rectifier. As a result, the multiplication of batteries, and therefore of electrical converters, has a significant impact on the weight of the aircraft and therefore on its electrical energy consumption during a flight.

[0010] The present invention improves the situation.

[0011] In this respect, the invention relates to an aircraft with a hybrid energy source comprising:

[0012] - at least two drive units each comprising a propeller and an electric motor,

[0013] - at least one stored electrical energy source arranged to supply electrical energy to one or more of the electric motors,

[0014] - at least one source of electrical generation comprising a fuel-fired electrical generator and connected to each source of stored electrical energy, and

[0015] - a power supply control arranged to issue a power command to the at least one electrical generation source according to the power requirements of the drive groups, the at least one stored electrical energy source being arranged to supply electrical energy according to the difference between the power requirements of the drive groups and the power supplied by the at least one electrical generation source on the basis of the power command, the at least one electrical generation source being further adapted to recharge the at least one stored electrical energy source so that each stored electrical energy source is processed passively.

[0016] Each electrical generation source comprises at least one electrical converter, which is connected to each stored electrical energy source via a respective junction including:

[0017] • a first metal-oxide gate field effect transistor and a second metal-oxide gate field effect transistor connected in series and with opposite on-directions, or

[0018] • two electrical circuits each comprising an insulated gate bipolar transistor and a reverse diode connected in parallel, the two electrical circuits being connected in series and in opposite directions.

[0019] The power supply control is arranged to control the operation of each junction according to a set of states consisting of: a unidirectional state in which current flows from the electrical converter to the stored electrical energy source, a bidirectional state in which current flows in both directions and a blocking state in which the flow of current is blocked.

[0020] In one or more embodiments, the first metal-oxide gate field effect transistor and the second metal-oxide gate field effect transistor of at least one junction are made of silicon carbide.

[0021] In one or more embodiments, at least one junction further includes an electronic component comprising a resistor connected in series with:

[0022] • a metal-oxide gate field effect transistor, or

[0023] • an electrical circuit comprising an insulated gate bipolar transistor and a reverse diode connected in parallel, the electronic component being arranged to allow precharging of the corresponding stored electrical energy source.

[0024] In one or more embodiments, at least one source of stored electrical energy is a battery.

[0025] In one or more embodiments, the training groups include at least one takeoff training group and at least one cruise training group.

[0026] For example, at least one takeoff training group is a vertical takeoff / landing training group and at least one cruise training group is a horizontal training group.

[0027] In one or more embodiments, the fuel-fired electrical power generator of at least one electrical generation source is a turbine engine and each electrical converter of the electrical generation source is an AC-DC converter.

[0028] The turboshaft engine can be powered by fuel, biofuel or synthetic gasoline.

[0029] In one or more embodiments, the fuel-fired electrical power generator of at least one electrical generation source is a fuel cell and each electrical converter of the electrical generation source is a direct current-to-direct current converter.

[0030] In one or more embodiments, the aircraft is arranged to operate at least in a turbo mode in which the power requirements of the drive units require a supply of power from the at least one electrical generation source and the at least one stored electrical energy source, and in which the power control controls each junction according to the unidirectional state.

[0031] In one or more embodiments, the aircraft is arranged to operate at least in a power saving mode in which the power control controls each junction according to the blocking state. In one or more embodiments, the aircraft is arranged to operate at least in a charging mode in which the power control issues a power command to the at least one electrical generation source to meet the power requirements of the drive units while charging the at least one stored electrical energy source.

[0032] Typically, in the charging mode, the power control sequentially controls each junction in one or more charging phases, the power control being arranged to implement each charging phase by associating each electrical converter with a respective stored electrical energy source, controlling each junction between an associated electrical converter and stored electrical energy source according to the unidirectional state and controlling any other junction according to the blocking state, until each stored electrical energy source is charged.

[0033] Advantageously, the aircraft comprises a plurality of stored electrical energy sources and, in the charging mode, the power supply control sequentially controls each junction in one or more charging phases, the power supply control being arranged to implement each charging phase by associating each electrical converter with several respective stored electrical energy sources, by controlling each junction between an associated electrical converter and stored electrical energy source according to the bidirectional state and by controlling any other junction according to the blocking state, until each stored electrical energy source is charged.

[0034] In one or more embodiments, the aircraft is arranged to operate at least in a buffer mode in which the power control issues a power command to the at least one electrical generation source to meet the power requirements of the drive units via the at least one stored electrical energy source, and in which the power control sequentially controls each junction in one or more power phases, the power control being arranged to implement each power phase by associating each electrical converter with a respective stored electrical energy source, controlling each junction between an associated electrical converter and stored electrical energy source according to the unidirectional state and controlling any other junction according to the blocking state, until the power requirements of the drive units are met.

[0035] Other characteristics, details and advantages will appear on reading the detailed description below, and on analyzing the attached drawings in which:

[0036] [Fig. 1] represents a schematic view of the electrical architecture of an aircraft according to the invention comprising a single source of electrical generation,

[0037] [Fig. 2] represents a schematic view of the electrical architecture of an aircraft according to the invention comprising two electrical generation sources,

[0038] [Fig. 3] illustrates a circuit for supplying batteries by electrical converters via junctions within the electrical architecture of an aircraft according to the invention,

[0039] [Fig. 4] illustrates the possible states of a junction,

[0040] [Fig. 5] schematically illustrates the structure of a junction,

[0041] [Fig. 6] schematically illustrates one embodiment of the structure of [Fig.

[0042] 5]

[0043] [Fig. 7] illustrates the power supply circuit of [Fig. 3] in an operating mode called “turbo mode” of the aircraft,

[0044] [Fig. 8] illustrates the turbo mode of [Fig. 7] in the event that a fault occurs at a battery level,

[0045] [Fig. 9] illustrates the turbo mode of [Fig. 7] in the event that a fault occurs in an electrical converter,

[0046] [Fig. 10] illustrates the power supply circuit of [Fig. 3] in an operating mode called “energy saving mode” of the aircraft, [Fig. 1 1 ] illustrates the power supply circuit of [Fig. 3] in an operating mode called “charging mode” or in an operating mode called “buffer mode” of the aircraft, and

[0047] [Fig. 12] illustrates the charging mode or buffer mode of [Fig. 1 1 ] in a particular case.

[0048] [Fig. 1] illustrates an aircraft 2 comprising a power control 4, a plurality of drive units 6, 8, 10, 12, 14 and 16, a plurality of stored electrical energy sources 18, 20, 22 and 24 and an electrical generation source 26.

[0049] Typically, the two drive groups 6 and 8 are cruise drive groups used during the phase of flight between takeoff and landing, while the four drive groups 10, 12, 14 and 16 are takeoff drive groups used during the takeoff phase.

[0050] For example, aircraft 2 may be an electric vertical takeoff and landing - or eVTOL - aircraft, in which case the four takeoff training groups 10, 12, 14 and 16 are vertical training groups and the two cruise training groups 6 and 8 are horizontal training groups.

[0051] In the example illustrated in [Fig. 1], the cruise drive group 6 comprises a DC-AC converter 30, an electric motor 32 and a thruster 34. Similarly, the cruise drive group 8 comprises a DC-AC converter 38, an electric motor 40 and a thruster 42.

[0052] The direct-alternating current converter 30 (respectively 38) can also be called an "inverter" - or "inverter" in English-speaking literature - and is arranged to generate an alternating current from a direct current.

[0053] The thruster 34 (respectively 42), which corresponds for example to a propeller, is arranged to allow the aircraft 2 to move in a substantially horizontal direction. In flight mode, the thruster 34 (respectively 42) consumes a power of the order of 150 kilowatts (kW).

[0054] The cruise drive group 6 (respectively 8) is connected at the input to a switch 36 (respectively 44) which makes it possible to connect this input to the output of the take-off drive group 10 (respectively 14) or to that of the take-off drive group 12 (respectively 16).

[0055] The take-off drive group 10 (respectively 12, 14 and 16) comprises a propeller 46 (respectively 50, 54 and 58) driven by an electric motor 62 (respectively 66, 70 and 74) and a propeller 48 (respectively 52, 56 and 60) driven by an electric motor 64 (respectively 68, 72 and 76).

[0056] In the context of the invention, the propellers 46, 48, 50, 52, 54, 56, 58 and 60 are considered as propellers, in the same way as the propellers 34 and 42.

[0057] The electric motors 62 and 64 (respectively 66 and 68, 70 and 72, 74 and 76) are respectively powered by direct-alternating current converters 78 and 80 (respectively 82 and 84, 86 and 88, 90 and 92). The direct-alternating current converters 78 and 80 (respectively 82 and 84, 86 and 88, 90 and 92) are connected to an electrical bus of the take-off drive group 10 (respectively 12, 14 and 16).

[0058] The stored electrical energy source 18 (respectively 20, 22 and 24) is arranged to store electrical energy in order to supply it to the take-off drive group 10 (respectively 12, 14 and 16) according to the power requirements thereof. Furthermore, the stored electrical energy sources 18 and 20 (respectively 22 and 24) are also arranged to supply electrical energy to the cruise drive group 6 (respectively 8) via the switch 36 (respectively 44).

[0059] To do this, the stored electrical energy source 18 (respectively 20, 22 and 24) is connected, by the electrical bus of the take-off drive group 10 (respectively 12, 14 and 16), to the direct-alternating current converters 78 and 80 (respectively 82 and 84, 86 and 88, 90 and 92). Furthermore, the electrical bus of each of the take-off drive groups 10 and 12 (respectively 14 and 16) is connected to a respective output of the latter to which the switch 36 (respectively 44) can be selectively connected.

[0060] The stored electrical energy source 18 (respectively 20, 22 and 24) is typically a battery pack, i.e., a battery pack of electrical accumulators each intended for storing electrical energy. Alternatively, the stored electrical energy sources 18, 20, 22 and 24 may be supercapacitors or a combination of batteries and supercapacitors.

[0061] In the remainder of the description, for the sake of brevity, the stored electrical energy source 18 (respectively 20, 22 and 24) is called battery 18 (respectively 20, 22 and 24).

[0062] Typically, batteries 18, 20, 22 and 24 together deliver a power of around 800 kilowatts (kW) at 100% of their respective capacities.

[0063] The electrical generation source 26 is arranged to generate electrical energy and supply each of the batteries 18, 20, 22 and 24. To do this, the electrical generation source 26 has several electrical distribution buses.

[0064] In the example of [Fig. 1], the electrical generation source 26 is connected to a first input and a second input of each of the take-off drive groups 10, 12, 14 and 16 respectively via a first electrical distribution bus and a second electrical distribution bus. The electrical distribution buses make it possible to connect each take-off drive group 10, 12, 14 and 16 to the respectively associated battery 18, 20, 22 and 24.

[0065] In the example of [Fig. 1], the electrical generation source 26 comprises two electrical converters 94 and 96 as well as a fuel-fired electrical energy generator 98.

[0066] More particularly here, the electrical converters 94 and 96 are AC-DC converters while the fuel-fired electrical power generator 98 is a turbine engine, for example a turbine generator - or turbogenerator. The AC-DC converter 94 is connected to the respective first inputs of the take-off drive groups 10, 12, 14 and 16. Thus, the AC-DC converter 94 defines the starting point of each first electrical distribution bus connecting the electrical generation source 26 respectively to the first inputs of the take-off drive groups 10, 12, 14 and 16. Similarly, the AC-DC converter 96 is connected to the respective second inputs of the take-off drive groups 10, 12, 14 and 16.Thus, the AC-DC converter 96 defines the starting point of each second electrical distribution bus connecting the electrical generation source 26 respectively to the second inputs of the take-off drive groups 10, 12, 14 and 16.

[0067] The AC-DC converter 94 (respectively 96) may also be called a "rectifier" - or "rectifier" in English literature - and is arranged to generate a direct current from an alternating current.

[0068] Typically, the 98 turboshaft engine can deliver power in the order of 300 kilowatts (kW) at 100% of its capacity.

[0069] It should be noted that the electrical generation source 26 can operate on both direct current and alternating current, in which case the converters 94 and 96 are, as the case may be, alternating-direct current converters or direct-direct current converters - or "DC-to-DC converter" in the English literature.

[0070] The electrical generation source 26 may thus be based on a turbine engine powered by a tank of conventional fuel, biofuel, or synthetic gasoline (also known as “synfuel”). In such a case, the electrical converters 94 and 96 are AC-DC converters. Alternatively, the electrical generation source 26 may be based on a hydrogen-based energy source, such as a fuel cell. In such a case, the electrical converters 94 and 96 are DC-DC converters. In the context of the invention, such energy sources are considered to be fuel-fired electrical energy generators. The power supply control 4 is a low-voltage device arranged to control, on the one hand, the electrical generation source 26 and, on the other hand, the switches 36 and 44, as well as various protection elements not shown in [Fig. 1],

[0071] The electrical architecture of the aircraft 2 allows for real hybridization of the batteries 18, 20, 22 and 24, and not just a simple juxtaposition. Thus, depending on the power requirements, the batteries 18, 20, 22 and 24 and the electrical generation source 26 can operate in concert.

[0072] The batteries 18, 20, 22 and 24 are conventional batteries whose operation is governed by a conventional control system (better known by the acronym BMS for “Battery Management System”). Such a system makes it possible to perform functions such as monitoring parameters – voltage, temperature, state of charge, state of health, etc. –, preventing any risk of leaving the intended operating range – overvoltage, overcurrent, overheating, etc. – or optimizing the battery’s capacities. In the context of the invention, no other intelligence, in particular software or hardware, is necessary. Consequently, the batteries 18, 20, 22 and 24 are treated passively in the sense that their integration does not require any particular adaptation apart from the manner, detailed below, in which the batteries 18, 20, 22 and 24 are connected to the electrical converters 94 and 96.From the point of view of the rest of the electrical architecture of aircraft 2, batteries 18, 20, 22 and 24 are seen as simple energy buffers - in the sense here of the English term "buffer". This goes against existing solutions in which: either an element is specifically provided to optimize the operation of the batteries and plays a control role, or an element is provided to compensate for a possible failure of the batteries, but in exclusive alternation, that is to say without the batteries and this element being able to operate simultaneously.

[0073] In the embodiment illustrated in [Fig. 1], the aircraft 2 comprises a single electrical generation source, namely the electrical generation source 26. However, it should be understood here that the aircraft 2 may comprise a plurality of electrical generation sources.

[0074] For example, [Fig. 2] shows an embodiment in which the aircraft 2 comprises two electrical generation sources 26 and 28. The electrical generation source 26 (respectively 28) comprises an electrical converter 94 (respectively 96) and a fuel-fired electrical generator 98 (respectively 100).

[0075] In the example of [Fig. 2], the fuel-fired electric generator 98 (respectively 100) is a turbine engine and the electric converter 94 (respectively 96) is an alternating-direct current converter.

[0076] Typically, the fuel-fired electrical generators 98 and 100 may each deliver power on the order of 150 kilowatts (kW) at 100% of their respective capacities. Again, each of the electrical generation sources 26 and 28 may be based on a turbine engine powered by a tank of conventional fuel, biofuel, or synthetic gasoline. Alternatively, a power source powered by a hydrogen tank, such as a fuel cell, may be used.

[0077] The overall electrical architecture of aircraft 2 has been described with reference to [Fig. 1] and [Fig. 2],

[0078] As detailed previously, the aircraft 2 comprises at least one electrical generation source - a single electrical generation source 26 in [Fig. 1], two electrical generation sources 26 and 28 in [Fig. 2] - arranged to supply one or more sources of stored electrical energy - four batteries 18, 20, 22 and 24 in [Fig. 1] and [Fig. 2],

[0079] Aircraft 2 is a hybrid power source aircraft and as such generally includes more batteries than electrical generation sources. Furthermore, the starting point of each electrical distribution bus of each electrical generation source is defined by an electrical converter - here the AC-DC converters 94 and 96 - so that the number of electrical converters is reduced and the weight of aircraft 2 is reduced. In other words, the electrical converters are at the electrical generation sources and not at the batteries.

[0080] For illustration purposes, the electrical architectures respectively shown in [Fig. 1] and [Fig. 2] comprise only two electrical converters 94 and 96 for four batteries 18, 20, 22 and 24.

[0081] However, this advantage relative to the weight of the aircraft 2 has a counterpart: the batteries 18, 20, 22 and 24 are connected to each other via the electrical generation source(s) 26 and 28. Consequently, any short circuit occurring at the level of an electrical generation source or a battery is likely to propagate.

[0082] To solve this problem, the Applicant proposes the power supply circuit shown in [Fig. 3]. In the remainder of the description, we will now focus on how the electrical converters are connected to the batteries.

[0083] [Fig. 3] illustrates a circuit for supplying one or more stored electrical energy sources B1,...,BM by one or more electrical converters E1,...,EN. Here, M is a non-zero natural integer corresponding to the number of stored electrical energy sources while N is a non-zero natural integer corresponding to the number of electrical converters.

[0084] It is understood that the power supply circuit described here is a generalization of the part of the electrical architecture of [Fig. 1] or [Fig. 2] relating to the electrical converters 94 and 96 and to the batteries 18, 20, 22 and 24. Thus, taking M = 4 and N = 2, we find the same configuration as that of [Fig. 1] or [Fig. 2], the sources of stored electrical energy B1, B2, B3 and B4 corresponding respectively to the batteries 18, 20, 22 and 24; the electrical converters E1 and E2 corresponding respectively to the electrical converters 94 and 96.

[0085] For the sake of brevity, the stored electrical energy sources B1,...,BM are respectively referred to as batteries B1,...,BM hereinafter. It should be noted that it is possible for only one electrical converter to be present in the electrical architecture of the aircraft 2, in which case N = 1. Without loss of generality, it is considered in the remainder of the description that there are a plurality of electrical converters E1,...,EN and a plurality of batteries B1

[0086] As illustrated in [Fig. 3], each electrical converter E1 ,...,EN is connected to each battery B1 ,...,BM by a respective junction 102. Consequently, the power supply circuit comprises as many junctions as there are possible pairs formed of an electrical converter E1 ,...,EN and a battery B1 ,...,BM, i.e. NxM junctions 102.

[0087] As illustrated in [Fig. 4], the junction 102 is arranged to operate exclusively in three possible states: a unidirectional state, a bidirectional state and a blocking state. More specifically, the operation of each junction 102 is controlled by the power supply control 4.

[0088] In the unidirectional state, junction 102 allows current to flow from the electrical converter to the battery. Of course, current cannot then flow in the opposite direction, i.e., from the battery to the electrical converter.

[0089] In the bidirectional state, junction 102 allows current to flow in both directions, namely from the electrical converter to the battery but also from the battery to the electrical converter.

[0090] Finally, in the blocking state, junction 102 blocks the flow of current, in either direction.

[0091] It should be understood here that junction 102 can only operate in these three states. In particular, power supply control 4 cannot control junction 102 to operate in a state in which current could only flow from the battery to the electrical converter.

[0092] The structure of junction 102 is discussed below with reference to [Fig. 5] and [Fig. 6].

[0093] In one embodiment illustrated in [Fig. 5], the junction 102 is made using the technology of the metal-oxide gate field effect transistor (better known by the English acronym MOSFET for "Metal Oxide Semiconductor Field Effect Transistor") - or insulated gate field effect transistor. More particularly, the junction 102 comprises a first MOSFET 104 and a second MOSFET 106 connected in series. Each MOSFET 104, 106 comprises three electrodes - the gate, the drain and the source - which together form a semiconductor 108, 112. Furthermore, each MOSFET 104, 106 also comprises a parasitic element formed by the pn junction between the drain and the source: a diode 110, 114. The diode 110, 114 - often called a "body diode" in the English literature - is inherent to the MOSFET 104, 106.

[0094] The on-direction of each diode 110, 114 is opposite to that of the corresponding semiconductor 108, 112. The expression "on-direction" here designates the direction of current flow. Thus, for the semiconductor 108, 112, the current flows from the drain to the source for an N-type channel - as in [Fig. 5] -, and from the source to the drain for a P-type channel.

[0095] To give the junction 102 the properties illustrated in [Fig. 4], namely possible operation according to the unidirectional state, the bidirectional state and the blocking state, the first MOSFET 104 and the second MOSFET 106 are connected so that their respective semiconductors 108, 112 are in opposite conductive directions. In an equivalent manner, the respective diodes 110, 114 of the first MOSFET 104 and the second MOSFET 106 are then also in opposite conductive directions. The first MOSFET 104 and the second MOSFET 106 are therefore connected in series and in opposite conductive directions.

[0096] Each MOSFET 104, 106 is for example a silicon carbide MOSFET (better known by the English acronym SiC for "silicon carbide") - or SiC MOSFET.

[0097] The junction 102 is in the unidirectional state when the first MOSFET 104 is in the blocking state and the second MOSFET 106 is in the on state. In other words, the junction 102 is in the unidirectional state when only the MOSFET whose semiconductor has a forward direction from the electrical converter to the battery is in the on state. The junction 102 is in the bidirectional state when the first MOSFET 104 and the second MOSFET 106 are in the on state. The junction 102 is in the blocking state when the first MOSFET 104 and the second MOSFET 106 are in the off state. The state - blocking or conducting - of each MOSFET 104 and 106 is controlled by the power supply control 4. To do this, the power supply control 4 applies to the gate of each MOSFET 104, 106 the voltage necessary to make it switch from the blocking state to the conducting state.

[0098] Alternatively, each MOSFET 104, 106 may be replaced by an insulated gate bipolar transistor (IBBT) connected in parallel with a reverse diode, i.e. a diode whose on-direction is opposite to that of the IGBT. In such an embodiment, each IGBT therefore replaces the semiconductor 108, 112 of a MOSFET 104, 106 while each reverse diode replaces the diode 110, 114.

[0099] Junction 102 then comprises two electrical circuits connected in series, each electrical circuit comprising an IGBT and a reverse diode connected in parallel. These two electrical circuits are also in opposite passing directions, whether their respective IGBTs or their respective reverse diodes are compared.

[0100] [Fig. 6] represents an embodiment in which, within the junction 102, the first MOSFET 104 and the second MOSFET 106 are associated with an electronic component 116. More precisely, the first MOSFET 104 and the second MOSFET 106 are connected in series on the positive wire - or "positive wire" in English -, while the electronic component 116 is arranged on the negative wire - or "negative wire" in English.

[0101] The electronic component 116 comprises a MOSFET 118 and a resistor 120 connected in series. Like the first MOSFET 104 and the second MOSFET 106, the third MOSFET 118 comprises a semiconductor 122 and a parasitic diode 124.

[0102] The electronic component 116 is arranged on the negative wire so that the conductive direction of the third MOSFET 118 is from the battery to the electrical converter. In an equivalent manner, the conductive direction of the diode 124 is from the electrical converter to the battery. As illustrated in [Fig. 6], the third MOSFET 118 is in fact oriented in the same way as the first MOSFET 104.

[0103] The third MOSFET 1 18 is for example a SiC MOSFET. Furthermore, here again, the third MOSFET 1 18 can be replaced by an IGBT connected in parallel with a reverse diode.

[0104] The electronic component 1 16 allows the corresponding battery to be pre-charged via the negative wire.

[0105] The use of a transistor - whether a MOSFET or an IGBT - makes it possible to reduce the mass of the junction 102 compared to a solution in which the junction 102 would be made with electromechanical contactors or relays. For illustration, the mass of a SiC MOSFET is around 6 grams (g) compared to around 750 grams (g) for an electromechanical relay. In addition to being heavier and more bulky, electromechanical contactors and relays also have the disadvantage of including moving parts - the contacts - which increase the risk of failure (friction, sparks) when the power is restored or cut off.

[0106] As detailed below, the proposed power supply circuit, and in particular the use of the junctions 102, adapts both to the nominal operation of the aircraft 2 and in the event of a failure, i.e. when at least one battery is unavailable or when at least one electrical converter is unavailable.

[0107] [Fig. 7] illustrates an operating mode of aircraft 2 - or turbo mode - in which the power requirements of the drive units, and more precisely of their respective electric motors, are very high to the point that the batteries B1,...,BM and the source(s) of electrical generation, therefore the electrical converters E1,...,EN, are used to the maximum of their capacities.

[0108] The power supply control 4 then controls each junction 102 to operate according to the unidirectional state. Thus, each electrical converter E1,...,EN supplies power to each battery B1,...,BM. In the event of a failure, for example a short circuit, at one of the batteries B1,...,BM, this cannot propagate to the other batteries B1,...,BM since the current generated by a short circuit is blocked by each junction 102 to which the faulty battery is connected. The same is true in the case where the failure occurs at an electrical converter: the current generated by a short circuit cannot flow from a battery to the faulty electrical converter.

[0109] In either case, the power supply control 4 can then isolate the faulty element. To do this, the power supply control 4 controls the junctions 102 connected to the faulty element to change them from the unidirectional state to the blocking state.

[0110] In the case, illustrated in [Fig. 8], where a fault occurs at battery B1, the power supply control 4 isolates battery B1 by switching all junctions 102 via which the electrical converters E1,...,EN are connected to battery B1 from the unidirectional state to the blocking state. Furthermore, given that a battery, here battery B1, is no longer powered, the electrical energy originally intended for it can be distributed to the other batteries, here batteries B2,...,BM. It is understood that the power supply circuit is sufficiently flexible to implement dynamic power allocation and thus provide electrical energy to a battery whose needs are higher than those of the others.

[0111] In the case, illustrated in [Fig. 9], where a fault occurs at the level of the electrical converter E1, the power supply control 4 isolates the electrical converter E1 by switching all the junctions 102 via which the electrical converter E1 is connected to the batteries B1,...,BM from the unidirectional state to the blocking state.

[0112] [Fig. 10] illustrates an operating mode of aircraft 2 - or energy saving mode - in which no power is required from the electrical generation source(s), i.e. from the electrical converters E1,...,EN.

[0113] The power supply control 4 then controls each junction 102 to operate according to the blocking state. In the event of a failure, for example a short circuit, at one of the batteries B1,...,BM or one of the electrical converters E1,...,EN, this cannot propagate since the current generated by a short circuit is blocked by each junction 102.

[0114] [Fig. 1 1 ] illustrates an operating mode of the aircraft 2 - or charging mode - in which the power requirements of the drive units, and more precisely of their respective electric motors, are low to the point that the electrical converters E1 ,...,EN supply the drive units with electrical energy via the batteries B1 ,...,BM while charging the latter.

[0115] To do this, each electrical converter E1,...,EN is respectively associated with a battery among the batteries B1,...,BM.

[0116] The power supply control 4 then controls each junction 102 so that the junction 102 between an electrical converter and the battery associated with it is in the unidirectional state, and the other junctions 102 - that is to say each junction 102 between an electrical converter and a battery which are not associated - are in the blocking state.

[0117] When the N batteries each associated with an electrical converter are charged, the electrical converters E1,...,EN, are all assigned a new battery to charge and so on. The batteries B1,...,BM are thus sequentially charged N at a time at most per charging phase - or iteration. Of course, an electrical converter E1,...,EN may not be associated with a new battery if the number of batteries remaining to be charged is strictly less than the number of electrical converters.

[0118] [Fig. 11] thus illustrates an iteration in which the electrical converter E1 is associated with the battery B1 and in which the electrical converter EN is associated with the battery BM.

[0119] If M is divisible by N, then the number of iterations required to charge all batteries B1,...,BM is M / N. On the other hand, if M is not divisible by N, the number of iterations required to charge all batteries B1,...,BM is [M / NJ+1, where [■] is the integer part function. For the last iteration, therefore to charge a number of batteries equal to the remainder of the Euclidean division of M by N, it is possible to use all the electrical converters in order to charge the remaining batteries more quickly. The selection, at each iteration, of the N batteries to be charged can depend on the respective charge levels of the batteries for example to give priority to batteries with the lowest charge level or, conversely, to batteries with the highest charge level.

[0120] Furthermore, [Fig. 1 1] also illustrates another mode of operation of the aircraft 2 - or buffer mode - in which the power requirements of the drive units, and more precisely of their respective electric motors, are low, but in which the batteries B1,...,BM do not need to be charged.

[0121] Batteries B1,...,BM are treated passively, as energy buffers. In other words, the power supplied by the electrical converters E1,...,EN simply passes through batteries B1,...,BM to power the drive units.

[0122] In a manner similar to the charging mode, the power supply control 4 implements one or more power supply phases - or iterations. At each iteration, each electrical converter E1,...,EN is respectively associated with one of the batteries B1,...,BM. The power supply control 4 then controls each junction 102 so that the junction 102 between an electrical converter and the battery with which it is associated is in the unidirectional state, and the other junctions 102 - i.e. the respective junctions 102 between an electrical converter and the batteries with which it is not associated - are in the blocking state. The buffer mode ends when the power requirements of the drive groups are satisfied.

[0123] In the example of [Fig. 1 1], each electrical converter is successively associated with a battery. However, it is also possible to associate, at each iteration, several batteries with each electrical converter.

[0124] Thus, in the case illustrated in [Fig. 12], each of the electrical converters E1 ,...,EN is respectively associated with a number P of batteries, where P is a natural integer greater than or equal to 2. In this case, the electrical converter E1 is associated with the first P batteries, namely the batteries B1 ,...,BP, while the electrical converter EN is associated with the last P batteries, namely the batteries BM-P+1 ,...,BM.

[0125] The power supply control 4 then controls each junction 102 so that the junction 102 between an electrical converter and a battery associated with it is in the bidirectional state, and the other junctions 102 - that is to say each junction 102 between an electrical converter and a battery which are not associated - are in a blocking state.

[0126] Thus, in the example of [Fig. 12], the junction 102 between each of the batteries B1,...,BP and the electrical converter E1 is in the bidirectional state. Similarly, the junction 102 between each of the batteries BM-P+1,...,BM and the electrical converter EN is in the bidirectional state. On the other hand, the junction 102 between each of the batteries B1,...,BP and the electrical converters other than E1 is in the blocking state. Similarly, the junction 102 between each of the batteries BM-P+1,.,.,BM and the electrical converters other than EN is in the blocking state.

[0127] In other words, if we consider a given battery, it is connected to the N electrical converters E1,...,EN via N respective junctions 102 and, in the case of [Fig. 12], these N junctions 102 are controlled by the power supply control 4 as follows: the junction 102 between the given battery and the associated electrical converter is in the bidirectional state, while the other N-1 junctions 102 are in the blocking state.

[0128] In the charging mode of aircraft 2, the embodiment of [Fig. 12] has the advantage of reducing the charging time.

[0129] The bidirectional state of the junctions 102 between an electrical converter and the P batteries with which it is associated makes it possible to obtain a crossflow between these P batteries so that they are only seen by the associated electrical converter as a single battery.

[0130] The consequence of bidirectionality is that any failure, for example a short circuit, which occurs at a battery propagates to the P-1 other batteries associated with the same electrical converter. This effect is however limited to the P batteries and does not propagate to the other batteries due to the blocking state of the junctions 102 by which these other batteries are connected to the electrical converter with which the faulty battery is associated.

[0131] The configuration of junctions 102 illustrated in [Fig. 12] can also be applied to the buffer mode, and not only to the charging mode.

Claims

Claims

1. Aircraft (2) with hybrid energy source comprising: - at least two drive units (6, 8, 10, 12, 14, 16) each comprising a propeller (34, 42, 46, 48, 50, 52, 54, 56, 58, 60) and an electric motor (32, 40, 62, 64, 66, 68, 70, 72, 74, 76), - at least one stored electrical energy source (18, 20, 22, 24) arranged to supply electrical energy to one or more of the electric motors (32, 40, 62, 64, 66, 68, 70, 72, 74, 76), - at least one electrical generation source (26, 28) comprising a fuel-fired electrical generator (98, 100) and connected to each stored electrical energy source (18, 20, 22, 24), and - a power supply control (4) arranged to issue a power command to the at least one electrical generation source (26, 28) as a function of the power requirements of the drive groups (6, 8, 10, 12, 14, 16), the at least one stored electrical energy source (18, 20, 22, 24) being arranged to supply electrical energy as a function of the difference between the power requirements of the drive groups (6, 8, 10, 12, 14, 16) and the power supplied by the at least one electrical generation source (26, 28) on the basis of the power command, the at least one electrical generation source (26, 28) being further adapted to recharge the at least one stored electrical energy source (18, 20, 22, 24) so ​​that each stored electrical energy source (18, 20, 22, 24) is passively treated, said aircraft (2) being characterized in that each electrical generation source (26, 28) comprises at least one electrical converter (94, 96),which is connected to each stored electrical energy source (18, 20, 22, 24) via a respective junction (102) including:, • a first metal-oxide gate field effect transistor (104) and a second metal-oxide gate field effect transistor (106) connected in series and with opposite on-directions, or • two electrical circuits each comprising an insulated-gate bipolar transistor and a reverse diode connected in parallel, the two electrical circuits being connected in series and in opposite passing directions, and in that the power supply control (4) is arranged to control the operation of each junction (102) according to a set of states consisting of: a unidirectional state in which the current flows from the electrical converter (94, 96) to the stored electrical energy source (18, 20, 22, 24), a bidirectional state in which the current flows in both directions and a blocking state in which the flow of the current is blocked.

2. Aircraft (2) according to claim 1, characterized in that the first metal-oxide gate field effect transistor (104) and the second metal-oxide gate field effect transistor (106) of at least one junction (102) are made of silicon carbide.

3. Aircraft (2) according to claim 1 or 2, characterized in that at least one junction (102) further includes an electronic component (1 16) comprising a resistor (120) connected in series with: • a metal-oxide gate field effect transistor (1 18), or • an electrical circuit comprising an insulated gate bipolar transistor and a reverse diode connected in parallel, said electronic component (1 16) being arranged to allow precharging of the corresponding stored electrical energy source (18, 20, 22, 24).

4. Aircraft (2) according to one of the preceding claims, characterized in that at least one stored electrical energy source (18, 20, 22, 24) is a battery.

5. Aircraft (2) according to one of the preceding claims, characterized in that the drive groups (6, 8, 10, 12, 14, 16) comprise at least one take-off drive group (10, 12, 14, 16) and at least one cruise drive group (6, 8).

6. Aircraft (2) according to claim 5, characterized in that at least one takeoff drive unit (10, 12, 14, 16) is a vertical takeoff / landing drive unit and at least one cruise drive unit (6, 8) is a horizontal drive unit.

7. Aircraft (2) according to one of the preceding claims, characterized in that the fuel-fired electric power generator (98, 100) of at least one electric generation source (26, 28) is a turbine engine and in that each electrical converter (94, 96) of said electrical generation source (26, 28) is an alternating-direct current converter.

8. Aircraft (2) according to claim 7, characterized in that the turbine engine is powered by fuel, biofuel or synthetic gasoline.

9. Aircraft (2) according to one of the preceding claims, characterized in that the fuel-fired electrical energy generator (98, 100) of at least one electrical generation source (26, 28) is a fuel cell and in that each electrical converter (94, 96) of said electrical generation source (26, 28) is a direct-direct current converter.

10. Aircraft (2) according to one of the preceding claims, characterized in that it is arranged to operate at least in a turbo mode in which the power requirements of the drive units (6, 8, 10, 12, 14, 16) require a supply of power from the at least one electrical generation source (26, 28) and the at least one stored electrical energy source (18, 20, 22, 24), and in which the power supply control (4) controls each junction (102) according to the unidirectional state.

11. Aircraft (2) according to one of the preceding claims, characterized in that it is arranged to operate at least in an energy saving mode in which the power supply control (4) controls each junction (102) according to the blocking state.

12. Aircraft (2) according to one of the preceding claims, characterized in that it is arranged to operate at least according to a charging mode in which the power control (4) issues a power command to the at least one electrical generation source (26, 28) to meet the power requirements of the drive units (6, 8, 10, 12, 14, 16) while charging the at least one stored electrical energy source (18, 20, 22, 24).

13. Aircraft (2) according to claim 12, characterized in that, in the charging mode, the power supply control (4) sequentially controls each junction (102) in one or more charging phases, the power supply control (4) being arranged to implement each charging phase by associating each electrical converter (94, 96) with a respective stored electrical energy source (18, 20, 22, 24), by controlling each junction (102) between an associated electrical converter and stored electrical energy source (18, 20, 22, 24) according to the unidirectional state and by controlling any other junction (102) according to the blocking state, and this until each stored electrical energy source (18, 20, 22, 24) is charged.

14. Aircraft (2) according to claim 12, characterized in that it comprises a plurality of stored electrical energy sources (18, 20, 22, 24) and in that, in the charging mode, the power supply control (4) sequentially controls each junction (102) in one or more charging phases, the power supply control (4) being arranged to implement each charging phase by associating each electrical converter with a respective plurality of stored electrical energy sources (18, 20, 22, 24), by controlling each junction (102) between an associated electrical converter and stored electrical energy source (18, 20, 22, 24) according to the bidirectional state and by controlling any other junction (102) according to the blocking state, until each stored electrical energy source (18, 20, 22, 24) is charged.

15. Aircraft (2) according to one of the preceding claims, characterized in that it is arranged to operate at least in a buffer mode in which the power control (4) issues a power command to the at least one electrical generation source (26, 28) to meet the power requirements of the drive units (6, 8, 10, 12, 14, 16) via the at least one stored electrical energy source (18, 20, 22, 24), and in which the power control (4) sequentially controls each junction (102) in one or more power supply phases, the power control (4) being arranged to implement each power supply phase by associating each electrical converter (94, 96) with a respective stored electrical energy source (18, 20, 22, 24), by controlling each junction (102) between an electrical converter and a stored electrical energy source (18, 20, 22, 24) associated according to the unidirectional state and in controlling any other junction (102) according to the blocking state, until the power requirements of the drive groups (6, 8, 10, 12, 14, 16) are satisfied.

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