Aircraft comprising a reversible rotary electrical machine

The invention concerns an aircraft comprising a reversible rotary electrical machine 30), a wheel (35) for imparting movement to a stream of air, linked to said machine (30), a first ventilation duct (10, 15) configured to supply said wheel (35) with air, an electricity distribution network (70), a reversible power converter (40) connected to said machine (30) and to said network (70), and a control circuit (50) configured to control said converter (40) for, in a motor operating mode of said machine (30), taking a supply current from said network (70) to supply said machine (30) and drive said wheel (35), and, in an alternator operating mode of said machine (30), in which a stream of air flows in said first ventilation duct (15) and imparts movement to said wheel (35), to provide supply power to said network (70) which is generated by said machine (30) driven by said wheel (35).

The invention relates to aircraft comprising a reversible rotary electrical machine operating in particular as a fan in its motor mode.

It is known that aircraft comprise numerous on-board equipment which consume electrical energy, even increasingly so. It is necessary, in normal operation of an aircraft, to generate a sufficient quantity of electrical energy when the aircraft is in a flight phase, during the take-off and landing phases, but this is also so in case of emergency, that is to say in what is referred to as emergency operation.

For this, it is known to adapt the specification of an electric current generator driven by a shaft coupled to an engine of the aircraft. This generator, also termed “Auxiliary Power Unit” (APU), is a turbine supplied with the fuel of the aircraft, whose role is to supply electrical energy and also to supply high temperature compressed air used either to start the engines, or for air conditioning or pressurization of the aircraft.

A generator dedicated to emergency operation is generally installed in the aircraft, and it is possible to adapt its specifications.

Energy storage modules are furthermore installed within the aircraft, generally linked to an electricity distribution network of the aircraft. These modules are for example formed by batteries and/or capacitors.

The generator and the modules make it possible to supply the required quantity of electrical energy to the consumers of the aircraft.

The invention aims to provide an aircraft capable of generating a sufficient quantity of electrical energy simply, conveniently and economically.

For this, the invention concerns an aircraft comprising:at least one rotary electrical machine;at least one wheel for imparting movement to a stream of air, linked to said at least one rotary electrical machine;at least one system to cool;at least one first ventilation duct configured to supply said wheel with air;an electricity distribution network;at least one power converter connected to said at least one rotary electrical machine and to said electricity distribution network andat least one control circuit configured to control said at least one power converter;said at least one rotary electrical machine is reversible and said at least one power converter is reversible, said at least one control circuit being configured to control said at least one reversible power converter for:in a first motor operating mode of said at least one reversible rotary electrical machine, taking a supply current from said electricity distribution network to electrically supply said reversible rotary electrical machine and thereby drive said at least one wheel for imparting movement to a stream of air, by virtue of which said at least one system to cool is cooled; andin a second alternator operating mode of said at least one reversible rotary electrical machine, in which a stream of air flows in said at least one first ventilation duct and imparts movement to said at least one wheel, providing supply power to said electricity distribution network, which power is generated by said reversible rotary electrical machine which is driven by said wheel.

By virtue of the invention, additional electrical energy is received without having to raise the specifications for the generator, and/or without having to add energy storage modules.

Advantageously, rather than supplying more electrical energy to the distribution network, it is possible to reduce the specifications of that generator and/or eliminate energy storage modules, for the same quantity of electrical energy supplied to the network.

By virtue of the invention, it is even possible to eliminate a generator dedicated to emergency operation.

Furthermore, the use of rotary electrical machines present in the aircraft enables very economical production of electrical energy, of course provided that those machines do not have a coefficient of use equal to 1 (that is to say provided they are not, without counting the phases of electrical energy generation according to the invention, already in motor operation all the time).

These rotary electrical machines operate in motor mode, that is to say as a fan for cooling a system to cool, for example only in phases of take-off, landing, and low altitude flight, in other words when the rate of flow of air entering a ventilation duct in which that system is installed is insufficient for that system to be able to cool without the assistance of the fan. The rest of the time, those rotary electrical machines may operate as an alternator in order to supply the distribution network with electrical energy.

According to a preferred feature, said at least one first ventilation duct comprises a device for regulating the rate of flow of the stream of air entering that first duct.

The first duct advantageously enables the wheel to be directly supplied with the air, which is at a sufficient pressure to drive the reversible rotary electrical machine and so generate electrical energy.

According to another preferred feature, the aircraft comprises a control module configured to control said device for regulating the rate of flow of the stream of air entering said first duct, by virtue of which said regulating device is able to minimize the rate of flow of air in motor mode and adapt or even maximize the rate of flow of air in alternator mode, depending on the need for energy in the network.

Advantageously, this regulating device makes it possible to adapt, or even maximize, the rate of flow of air passing within the first duct and supplying the wheel. Thus, the electrical power generated by the rotary electrical machine may be adapted, or even maximized, simply and conveniently.

According to preferred features of the aircraft according to the invention that are simple, convenient and economical:the aircraft comprises at least one second ventilation duct in which are disposed said at least one reversible rotary electrical machine and at least partially said at least one system to cool; andthe first ventilation duct is juxtaposed against said second ventilation duct and comprises an air inlet and an opposite air outlet, which air outlet discharges into said second ventilation duct.

Advantageously, the air supplying the wheel is conveyed both by the first ventilation duct and by the second ventilation duct.

According to another preferred feature, the aircraft comprises at least one energy storage module electrically connected to said electricity distribution network.

Thus, the electrical energy generated by the reversible rotary electrical machine is sent either directly to the electricity distribution network, or to the energy storage module.

According to other preferred features of the aircraft according to the invention that are simple, convenient and economical:at least one control circuit is configured to control the power delivered by said at least one reversible rotary electrical machine by adapting the current passing through at least one reversible converter;at least one control circuit is configured to control the voltage supplied by at least one reversible converter to said electricity distribution network;at least one control circuit is configured to control the current supplied by at least one reversible converter to said electricity distribution network, by virtue of which said at least one rotary electrical machine acts as a source of current;the aircraft comprises a d.c./d.c. type electrical energy coupling device disposed between a first reversible converter and a second reversible converter, said first reversible converter being connected to said at least one reversible rotary electrical machine and said second reversible converter being connected to said distribution network, said at least one control circuit being configured to control the voltage supplied by said d.c./d.c. type electrical energy coupling device to said second reversible converter;the aircraft comprises at least one energy storage module connected to the distribution network and to said at least one reversible converter, and a checking unit which is configured to check said at least one control circuit, said checking unit furthermore being configured to check the voltage at the terminals of said at least one energy storage module.the checking unit is configured to check the quantities of current entering and current leaving said at least one energy storage module; andthe distribution network transports alternating or direct current electrical energy.

The control circuit and the checking unit are adapted to control and/or check, for example the reversible power converter, according to different energy management strategies.

According to still another preferred feature, at least one reversible rotary electrical machine operates in alternator mode when the aircraft is in what is referred to as emergency operation.

In this emergency operation, one or more reversible rotary electrical machines may generate and supply part of or all the required electrical energy.

If only part of the energy is supplied, the rest of the required energy may be supplied for example by one or more energy storage modules.

It is thus possible to reduce the specifications of the generator dedicated to the emergency operation, or even to eliminate it. According to still another preferred feature, the system to cool is a heat exchanger.

This heat exchanger is used for cooling a fluid (air or liquid) flowing in a cooling system integrated into the aircraft, which system is adapted to cooperate with air conditioning of the aircraft, or to cool consumers of electricity.

FIG. 1illustrates an aircraft1provided with a fuselage6, which has a front part2and a rear part3, wings4each of which is attached to the fuselage6at a central part thereof, and two engines5, each of those engines5being attached to a lower wall of a respective wing4and extending from the respective wing4parallel to the fuselage6towards the front part2of the aircraft1.

This aircraft1further comprises, in the rear part3of its fuselage6, a main ventilation duct10and a dedicated ventilation duct15which is juxtaposed against the main ventilation duct10.

In the rear part3of its fuselage6, the aircraft1further comprises an integrated system20for cooling a fluid adapted to supply for example an air conditioning system of the aircraft1and/or adapted to cool electrical consumers.

This integrated cooling system20is partially disposed in the main ventilation duct10.

The aircraft1further comprises a heat exchanger25situated in the vicinity of the integrated cooling system20and which is adapted to cool the fluid passing in that cooling system20by virtue of the circulation of that fluid through the heat exchanger25.

The heat exchanger25is disposed within the main ventilation duct10.

The aircraft1further comprises a reversible rotary electrical machine30situated in the vicinity of the heat exchanger25and disposed within the main ventilation duct10.

This reversible rotary electrical machine30comprises a rotor (not shown) able to turn about a longitudinal axis so as to drive an output shaft34(FIGS. 4 to 9), and a stator (not shown) mounted around the rotor.

The longitudinal axis constitutes the output shaft and the rotational axis of the rotor of the reversible rotary electrical machine30.

The aircraft1further comprises a wheel35for imparting movement to a stream of air, which is mounted on the output shaft34of the reversible rotary electrical machine30, externally thereof.

The wheel35has a set of blades whose free end substantially follows the profile of the inner surface of the main ventilation duct10.

The wheel35is thus here disposed within that main ventilation duct10.

The assembly formed by the reversible rotary electrical machine30and the wheel35for imparting movement to a stream of air forms a fan adapted to send cold air (by extraction or blowing) in the direction of the heat exchanger25in order to cool it.

In this case, it is the reversible rotary electrical machine30which is electrically supplied and which drives the wheel35to impart movement to a stream of air.

In addition to rotationally driving the wheel35to impart movement to a stream of air in the direction of the heat exchanger25(motor mode), the reversible rotary electrical machine30is capable of being rotationally driven by that wheel35, itself driven by a stream of air passing in the dedicated ventilation duct25, to produce electrical energy (alternator mode).

For this, the aircraft1further comprises an electricity distribution network70connected to the reversible rotary electrical machine30.

The aircraft1also comprises a checking unit60, a control circuit50as well as a reversible power converter40.

The reversible power converter40is connected to the rotary electrical machine30, to the control circuit50and to the electricity distribution network70.

The control circuit50is furthermore connected to the checking unit60.

This checking unit60is furthermore connected to the electricity distribution network70.

The aircraft1further comprises energy storage modules65connected to the checking unit60and also connected to the electricity distribution network70.

These energy storage modules65comprise for example a supply battery (of Nickel-Cadmium type), and/or a plurality of capacitive cells for forming at least one supercapacitor, or even several of them in parallel.

The dedicated ventilation duct15has a device for regulating the rate of flow of air entering that duct15.

The aircraft1further comprises a control module55adapted to control the regulating device17of the duct15.

This control module55is connected to the checking unit60.

The checking unit60here forms a part of a main checking unit of the aircraft1.

FIG. 2illustrates the main ventilation duct10in isolation with, inside it, the heat exchanger25, the reversible rotary electrical machine30and the wheel (not visible in that Figure).

This main ventilation duct10comprises an air inlet11and an air outlet12which are formed in the fuselage6of the aircraft1, that air inlet11being directed towards the lower part2and the air outlet12being directed towards the rear part3.

This air inlet11of the main ventilation duct10has a curved form which diverges towards the inside of that main duct10, well-know under the name NACA type air inlet.

This main ventilation duct10has a first section13extending from the air inlet11, that first section having a flared shape up to a second section14which is widened relative to the first section13.

In that second section14the heat exchanger25is disposed.

This main ventilation duct10furthermore has a third section18which is narrowed relative to the second section14, the reversible rotary electrical machine30and the wheel35being disposed in that third section18.

The main ventilation duct10has a fourth section19extending from the third section18to the air outlet12, this fourth section again being narrowed relative to the third section and moreover being bent.

FIG. 3illustrates this same main ventilation duct10with in addition the dedicated ventilation duct15juxtaposed against the main ventilation duct10.

This dedicated ventilation duct15has an air inlet16and an air outlet (which is not shown) which discharges directly into the main ventilation duct10at the junction between the second section14and the third section18, in other words at the location of the wheel35joined to the shaft34of the reversible rotary electrical machine30.

The dedicated ventilation duct15has a first wall22which is flat and disposed facing the first and second sections13and14of the main ventilation duct10, that first wall22extending between the air inlet16and the air outlet (not shown) of that dedicated ventilation duct15.

The dedicated ventilation duct15furthermore has a second wall21which curves away from the first wall22and extends between the air inlet16and the air outlet (not shown) of the dedicated duct15.

The dedicated ventilation duct15furthermore has a third wall23and a fourth wall24facing each other and connecting the first wall22and the second wall21, its third and fourth walls23,24being flat.

The dedicated ventilation duct15further comprises, at the location of its air inlet16, a movable door17.

This movable door17is connected to one end of the second wall21at the location of the air inlet16, and to the flat third and fourth walls23,24.

The door17is movable so as to regulate the rate of flow of the stream of air entering through that air inlet16.

FIG. 4diagrammatically and partially illustrates a first example embodiment of the electrical circuit of the aircraft1.

The reversible rotary electrical machine30is mechanically linked to the wheel35by the shaft34.

The reversible rotary electrical machine30is of three-phase type, each of its phases being electrically connected to the reversible power converter40.

This reversible converter40is capable of operating as a rectifier, that is to say to convert electrical energy of alternating type into electrical energy of direct type (AC/DC), and as an inverter, that is to say to transform electrical energy of direct type into electrical energy of alternating type (DC/AC).

As already indicated, this reversible converter40is electrically connected to the electricity distribution network70of the aircraft1.

The electricity distribution network70is electrically connected to the checking unit60, which is furthermore electrically connected to the control module55which is adapted to control the movable door17of the dedicated ventilation duct15.

The checking unit60and the converter40are both electrically connected to the control circuit50.

The control circuit50is furthermore electrically connected to the reversible rotary electrical machine30.

The checking unit60sends and receives information to and from the distribution network70, the control module55of the control circuit50, and also the main checking unit (not shown) of the aircraft1.

The control module55sends and receives information to and from the checking unit60, and sends the information to the movable door17for its movement in order to regulate the rate of flow of the air entering by the air inlet16of the dedicated ventilation duct15.

The control circuit50receives and sends information respectively to and from the checking unit60, the reversible converter40and the reversible rotary electrical machine30.

The reversible converter40is adapted to electrically transfer energy, through conversion, between the reversible rotary electrical machine30and the distribution network70.

The reversible rotary electrical machine30, as previously indicated, is adapted to be supplied by the electricity distribution network70via the reversible converter40to rotationally drive its shaft34and thereby rotationally drive the wheel35. When appropriate, the reversible rotary electrical machine30operates in motor mode.

This reversible rotary electrical machine30is furthermore adapted to be driven by its shaft34, which is first driven by the wheel35. When appropriate, the reversible rotary electrical machine30operates in alternator mode, that is to say that it generates alternating current electrical energy on those three phases which is converted into direct current electrical energy by the reversible converter40then transferred to the electricity distribution network70, which conveys it to the consumers and/or to the energy storage module65.

The control module is adapted to control the reversible power converter40depending on the mode of operation imposed on the reversible rotary electrical machine30.

The control circuit50receives commands from the checking unit60.

The control module55itself is adapted to control the movement of the movable door17. The control module55receives commands from the checking unit60.

With reference toFIG. 3, a description will now be given of the routing of the stream of air passing through the main ventilation duct10and in the dedicated ventilation duct15, according to the mode of operation of the reversible rotary electrical machine30.

Generally, and in particular when the aircraft1is in a high altitude flight phase, an air stream enters the main ventilation duct10via the air inlet11, which air stream enables the heat exchanger25to be cooled directly.

In this case, the reversible rotary electrical machine30operates in its alternator mode, with the movable door17being moved to create a stream of air having a sufficient rate of flow entering by the air inlet16and passing through the dedicated ventilation duct15to the air outlet (not shown), to finally supply the wheel35to make it turn. When appropriate, the wheel35drives the reversible rotary electrical machine30mechanically which generates additional electrical energy provided to the electricity distribution network70.

The door17is operated by the control module55so as to adapt, or even maximize, the rate of air flow when the reversible rotary electrical machine30operates in alternator mode, and to minimize it, or even eliminate it, when the reversible rotary electrical machine30operates in motor mode.

To be precise, depending on the rate of flow of air entering the dedicated ventilation duct15, and thus supplying the wheel35, the electrical power which can be generated by the reversible rotary electrical machine30varies. Of course, the higher the rate of air flow, the higher the power that can be generated, and conversely.

Thus, depending on the need for electrical energy of the electricity distribution network70(that is to say the electrical power absorbed by that network70), the checking unit60sends commands to the control module55which transforms them into data for moving the movable door17.

Of course, the power generated by the reversible rotary electrical machine30is directly adjustable by control of that machine30, where the door17has two modes, referred to as all or nothing, that is to say if it is open or closed.

In what is referred to as an emergency operating mode, it is also necessary to make the reversible rotary electrical machine30operate in its alternator operating mode.

Furthermore, by virtue of the electrical energy produced by the reversible rotary electrical machine30, it is possible to reduce the specifications of the main generator and/or of the emergency generator and/or to eliminate the energy storage modules installed in the aircraft1.

When the aircraft is in a low altitude flight phase, in other words at an altitude not making it possible to have a stream of air flowing in the main ventilation duct70with a sufficient rate of flow to cool the heat exchanger25through which that air passes, and when the aircraft1is in take-off or landing phase, the heat exchanger25must furthermore be cooled by virtue of the fan formed by the wheel35associated with the reversible rotary electrical machine30, which operates in motor mode.

When appropriate, the reversible rotary electrical machine30rotationally drives the wheel35which imparts movement to a stream of air within the main ventilation duct10, which stream is directed towards the heat exchanger25for it to be cooled.

A description will now be made with reference toFIG. 4of the implementation of the management of the energy provided to the electricity distribution network70in the particular case in which the reversible rotary electrical machine30operates in alternator mode.

This reversible rotary electrical machine30operates as an alternator and is thus considered as a source of electrical energy. However, within the aircraft1, there are generally other sources of electrical energy operating simultaneously (main and/or emergency energy sources)

It is preferable for a single source of energy to check the level of voltage on the electricity distribution network70, the other energy sources being power-regulated (that is to say with a current loop).

It may also be that the checking unit60is adapted to supervise all the energy sources of the aircraft1when they operate simultaneously, which checking unit60would where appropriate check the level of voltage on the electricity distribution network70.

When the electricity distribution network70delivers direct current electrical energy, in the case where the amplitude of the voltage on that network70is already regulated by a main power source (for example via the checking unit60), the control circuit50is adapted to perform current control of the reversible converter40operating as a rectifier via a control loop making it possible to control the torque of the shaft34of the reversible rotary electrical machine30(or of the rotor, or of the wheel35), or the speed of the shaft34or directly to control the power delivered by the reversible rotary electrical machine30.

When no main energy source other than the reversible rotary electrical machine30operating in alternator mode checks the amplitude of the voltage on the electricity distribution network70, the control circuit50is then adapted to control the amplitude of the voltage delivered by the reversible converter40operating as a rectifier on the electricity distribution network70, via an external control loop.

FIG. 5illustrates a second diagrammatic example of a circuit of the aircraft1.

In this example, the reversible rotary electrical machine30is directly connected to the electricity distribution network70, which is adapted to transport alternating current electrical energy.

No power converter is necessary between the network70and the machine30.

Where appropriate, the reversible rotary electrical machine30acts as a source of current directly connected to the network70.

FIG. 6illustrates a third diagrammatic example of a circuit of the aircraft1.

The difference in the diagrammatic electrical circuit ofFIG. 6relative to that ofFIG. 4lies in the fact that the electricity distribution network70now transports alternating rather than direct current electrical energy.

Furthermore, the power stage formed by the reversible converter40inFIG. 4is now formed by two reversible converters40and45as well as an electrical energy coupling device forming a reversible converter of d.c./d.c. type.

The reversible rotary electrical machine30is now connected to the first reversible converter40, which is electrically connected to device42.

The electricity distribution network70is now connected to the second reversible converter45, which is furthermore electrically connected to the device42.

The reversible power converters40and45are capable of operating as rectifiers and as inverters.

The device42comprises a filter, of low-pass type, and enables the transfer to be made between the direct current electrical energy delivered by the respective reversible converter40,45and supplied to the respective reversible converter45,40.

In this example, the control circuit50is electrically connected to each of the converters40and45and to the device42.

The control circuit50is adapted to control at the same time the reversible converter40, the reversible converter45and the device42.

The operation of this electrical circuit will now be described.

Where the amplitude and the frequency of the alternating voltage are controlled on the electricity distribution network70by a main power source, the power stage which converts the alternating current electrical energy supplied by the reversible rotary electrical machine30into alternating current electrical energy delivered by the reversible converter45in the distribution network70is regulated in power, in torque or in speed.

For this, the control circuit50is adapted to perform current control of the reversible converter40operating as a rectifier via a simple control loop so as to control the power delivered (that is to say the torque or the speed of the shaft34, or directly the power delivered by the machine30). The control circuit50is furthermore adapted to perform voltage control of the device45via an external control loop.

The control circuit50is also adapted to perform current control of the reversible converter45operating as an inverter via an internal control loop.

Where the amplitude and the frequency of the alternating voltage on the electricity distribution network is not regulated by a main energy source, the control circuit50is adapted to control the reversible converter40and the device42in the same way as above.

The control circuit50is furthermore adapted to perform current control of the reversible converter45operating as an inverter via an internal control loop and the control circuit50is adapted to control the amplitude and the frequency of the alternating voltage delivered by that reversible converter45via an external control loop.

FIG. 7illustrates a fourth example embodiment of the electrical circuit of aircraft1, in which an energy storage module65is electrically connected in parallel between the electricity distribution network70and the reversible converter40.

This is the only difference compared with the electrical circuit of the first example illustrated inFIG. 4, since the electricity distribution network70also transports direct current electrical energy.

This energy storage module65comprises a battery, with furthermore one or more supercapacitors.

In this fourth example, in the alternator operating mode of the reversible rotary electrical machine30, the reversible converter40delivers direct current electrical energy directly to the electricity distribution network70.

A description will now be given of the operation of this electrical circuit, in the case in which no other main energy source controls the amplitude of the voltage on the electricity distribution network70.

The management of the electrical energy generated by the reversible rotary electrical machine30and by the energy storage module65in parallel depends on the power absorbed by the electricity distribution network70.

This quantity of absorbed power may be measured directly on the network70by virtue of a voltage measurement, and/or by other measurements of current which may facilitate the management of energy.

When the energy storage module65acts as a source of voltage when the power absorbed on the network70is greater than the maximum power which can be supplied by the reversible rotary electrical machine30, two energy management strategies are possible depending on the quantity of power really absorbed.

If the power really absorbed on the network70is less than the maximum power that the reversible rotary electrical machine30can generate, that machine30alone generates the electrical energy required by the network70, without assistance from the energy storage module65.

The reversible rotary electrical machine30and the converter40thus act together as a voltage source.

Where appropriate, the control circuit50is adapted to perform current control of the reversible converter40acting as a rectifier via an internal control loop so as to control the torque on the shaft34, and the control circuit50is furthermore adapted to control the amplitude of the voltage delivered by the reversible converter40to the network70via an external control loop.

If the power really absorbed by the network70is greater than the maximum power which the reversible rotary electrical machine30can generate, the machine30generates its maximum power and the energy storage module65supplies the rest of the power required to attain the power really absorbed by the network70.

Where appropriate, the reversible rotary electrical machine30acts as a current source, and the control circuit50is adapted to perform current control of the reversible converter40via a single control loop. This regulation in fact corresponds to regulating the machine30to its maximum power value.

The energy storage module65furthermore acts as a voltage source.

Where appropriate, the checking unit60is adapted to control the amplitude of the voltage supplied to the distribution network70via a control loop, and checking unit60is optionally adapted to check the quantity of current entering and leaving the energy storage module65so as to monitor its state of charge.

In this fourth embodiment, it is also possible for the energy storage module65to continuously act as a voltage source, and two strategies may then be envisaged depending on the power really absorbed on the distribution network.

If the power really absorbed on the network70is less than the maximum power which the reversible rotary electrical machine30can generate, the energy storage module65then acts as a component through which the power delivered by that machine30transits.

Where appropriate, the checking unit60is adapted to check the amplitude of the voltage at the terminals of the energy storage module65, which voltage is delivered to electricity distribution network70.

Optionally, the checking unit60is furthermore adapted to check the quantity of current entering and leaving the terminals of the energy storage module65so as to check its state of charge.

If the power really absorbed on the electricity distribution network70is greater than the maximum power that the reversible rotary electrical machine30can generate, the energy storage module65supplies, in addition to the power generated by the machine30, the rest of the power required on the distribution network70.

In the same way, the checking unit60is adapted to check the amplitude of the voltage delivered by the energy storage module65to the electricity distribution network70, and, optionally, to check the quantity of current entering and leaving the terminals of the energy storage module65so as to check its state of charge.

FIG. 8illustrates a fifth example embodiment of the electrical circuit of the aircraft1.

Relative to the first example embodiment of the circuit illustrated inFIG. 4, the circuit illustrated inFIG. 9comprises an additional reversible rotary electrical machine30associated with an additional wheel35via an additional shaft34.

Furthermore, that additional rotary electrical machine30is electrically connected to an additional reversible converter40, which is electrically connected in parallel between the electricity distribution network70and the reversible converter40.

In this case there are thus two energy sources disposed in parallel, one being a reference source and the other being additional.

The control circuit50is then electrically connected to both reversible converters40.

The control circuit receives and sends information from and to each of the reversible converters40.

The operation of this circuit will now be described.

The operation in parallel of the first and second reversible rotary electrical machines30depends on the quantity of power really absorbed by the electricity distribution network70.

Let it be considered that one of the two reversible rotary electrical machines30is taken as reference.

If the power really absorbed on the network70is less than the maximum power which the reference reversible rotary electrical machine30can generate, that machine30by itself generates the power really absorbed in order to supply that network70, without the assistance of the other reversible rotary electrical machine30, which is thus controlled by the control circuit50in order not to supply any energy.

The reference reversible rotary electrical machine30thus acts as a source of voltage.

Where possible, the control circuit50is adapted to provide current control of the reversible converter40associated with that reference machine30so as to control the torque or the speed of the shaft34of that machine30, or its power.

Furthermore, the control circuit50is adapted to control the amplitude of the voltage delivered by that reversible converter40associated with the reference reversible rotary electrical machine30via an external control loop.

If the power really absorbed on the distribution network70is greater than the maximum power that the reference reversible rotary electrical machine30can generate, the latter supplies its maximum power and the rest of the power required is supplied by the other reversible rotary electrical machine30.

The reference reversible rotary electrical machine30thus acts as a source of current, and where appropriate, the control circuit50is adapted to provide current control of the reversible converter40associated with the reference machine30, via a single control loop which in fact enables that reference machine30to be set to its maximum power value.

The other reversible rotary electrical machine30thus acts as a source of voltage and where appropriate, the control circuit50is adapted to provide current control of the reversible converter40associated with that other machine30via an internal control loop, so as to control the torque on its shaft34.

Furthermore, the control circuit50is adapted to control the amplitude of the voltage delivered to the network70by the reversible converter40associated with the other machine30, via an external control loop.

To measure the amplitude of the voltage of the electricity distribution network70, it is possible to make direct measurements of voltage on that network70, and/or to make additional measurements of current.

A certain number of example embodiments of the electrical circuit of the aircraft1have just been described with the associated energy management strategies. It is of course possible to apply other energy management strategies, or to combine them, for example when more than two reversible rotary electrical machines30operate in alternator mode simultaneously, with or without an associated energy storage module.

In a variant not illustrated, the aircraft comprises other dedicated ventilation ducts of the same type as that which has just been described, which are each juxtaposed or not juxtaposed against a respective main ventilation duct, those dedicated ventilation ducts being dedicated to the supply air of the reversible rotary electrical machine.

For example, those other dedicated ducts and/or main ducts are installed in the ventral fairing of the aircraft, in the vicinity of the wings, fore or aft of the latter, or those other ducts are installed in the region of the front undercarriage of the aircraft.

In a variant not illustrated, the main ventilation duct and the dedicated ventilation duct are merged. In other words, there is no separate dedicated duct15, but the main duct alone supplies the wheel35with air. As appropriate, the main duct includes or does not include a regulating device as described for the dedicated duct15, that regulating device being controlled or not controlled by a control module as described above.

In a variant not illustrated, the electrical energy coupling device of d.c./d.c. type comprises, in addition to a filter, a surge limiter and/or a power dissipation unit.

In a variant not illustrated, the electrical energy coupling device comprises an energy storage system connected via a static converter, or uniquely comprises a block of capacitors. In all cases, this device is a filtering component contributing to putting into form the electrical energy processed by the reversible converter40, and optionally by the reversible converter45.

In a variant not illustrated, when the reversible rotary electrical machine associated with the wheel operates as a fan, it enables for example a non-pressurized zone to be ventilated to avoid the accumulation of fuel vapor.

In still another variant not illustrated, the control module enabling the regulating device present in the dedicated duct to be acted upon is integrated into the checking unit, and/or the control circuit enabling the reversible power converter to be controlled is integrated into the checking unit.

In still another variant not illustrated, the aircraft comprises an electrical energy control system dedicated to the emergency operation of the aircraft, which, when that emergency operation is triggered, takes control of the checking unit, of the control circuit, as well as of the control module, in order to make available all the functionalities required for implementing that operation.

In still another variant not illustrated, the air inlet16of duct15is closed, and where appropriate, either the machine30is controlled to generate a power residue with the air supplied by duct10, or the machine30is controlled so as not to supply power, or the wheel35is mechanically locked.

Of course, the geometry of the rotary electrical machine30and/or the wheel35and/or duct10and/or duct15may be modified to improve the aerodynamic performance.

It should be noted more generally that the invention is not limited to the examples described and represented.