Airship with Electric Distributed Propulsion System

Abstract

1. An airship comprising a number of generators (G1, G2, G3, G4), a number of electric buses (Bus 1, Bus 2, Bus 3, Bus 4), and a number of propulsion points (PXt, PXb, PY, PZbt, PZbb, PZst, PZsb), each of which comprises a propellant bundle formed from a number of thrusters (Xt1, Xt2, Xt3, Xt4, Xt5, Xt6; Xb1, Xb2, Xb3, Xb4, Xb5, Xb6; Y1, Y2, Y3, Y4; Zbt1, Zbt2, Zbt3, Zbt4; Zbb1, Zbb2, Zbb3, Zbb4; Zst1, Zst2, Zst3, Zst4; Zsb1, Zsb2, Zsb3, Zsb4) of the electric motor-driven propeller type. For each of the propulsion points, the thrusters are electrically connected to one of the generators by one of the electrical buses, and another thruster of the propulsion point is electrically connected to another of the generators by another of the electrical buses.

Description

[Technical field]

[0001] The present invention relates to an electric distributed propulsion system for an aircraft capable of hovering. The present invention further relates to an aircraft capable of hovering equipped with such a system, and more particularly to an airship capable of supporting heavy loads. [Background technology]

[0002] Typically, an aircraft propulsion system comprises two power generating units and two main electric buses, each connected to one of the two power generating units. Downstream, the propulsion system comprises a number of thrusters, each of which is typically connected to one of the two electric buses. This is the case, for example, for certain multirotor and vertical takeoff aircraft.

[0003] According to a typical configuration, the right propulsion point of the aircraft is electrically connected to a power generating unit located, for example, on the right side of the aircraft, while the left propulsion point of the aircraft is electrically connected to a power generating unit located, for example, on the left side of the aircraft.

[0004] For redundancy reasons, an electrical reconfiguration step is provided in case one of the two power units is defective. For example, a possible electrical reconfiguration is provided in order to power the left motor from the right-side generating unit in case the left-side generating unit fails. For this purpose, a backup electrical circuit must be provided that connects the left-side motor to the right-side generating unit. Naturally, the same is true between the right-side motor and the left-side generating unit.

[0005] EP 3521172 B1 discloses an electric propulsion system for an aircraft, comprising a first power reserve for supplying electric power and a second power reserve for supplying electric power, and a plurality of electric thruster units for providing a driving force to the aircraft. A power distribution unit is provided for transmitting electric power provided from a first energy accumulator and electric power provided from a second energy accumulator to the at least one electric thruster unit. The power distribution unit is also configured to charge the second power reserve using a first portion of the energy for the at least one thruster unit and a second portion of the energy for charging the second power reserve.

[0006] The backup circuits must therefore be electrically isolated from the electrical connection by the main bus in normal operation and must take over from the main bus in case of failure of an electrical unit. This means that they have substantially the same characteristics as the main bus. In addition to the payload of such backup circuits, which are not useful in normal operation but are only useful in case of failure, the control of these circuits requires actuators and effectors which may also be the source of failure.

[0007] The aim of the present invention is to overcome this drawback. Summary of the Invention

[0008] One object of the present invention is, inter alia, to remedy all or some of the above mentioned drawbacks.

[0009] According to a first aspect of the present invention, there is proposed an electric propulsion system for an aircraft having geostationary flight capability, comprising: -a number of generators; -a number of electric buses; a plurality of electric propulsion points;

[0010] In a propulsion system according to the present invention, at least one of the plurality of propulsion points includes a propellant bundle formed from a plurality of electric propeller thrusters.

[0011] The thruster in the propellant bundle is electrically connected to a generator in the plurality of generators by an electrical bus in the plurality of electrical buses, and at least one other thruster in the propellant bundle is electrically connected to another generator in the plurality of generators by another electrical bus in the plurality of electrical buses.

[0012] In a preferred version of the invention, each propulsion point comprises a propellant bundle formed of a plurality of electrically driven propeller-based thrusters, and at each propulsion point, the thrusters in that propellant bundle are electrically connected to a generator in the plurality of generators by an electric bus in the plurality of electric buses, and each other thruster in the propellant bundle is electrically connected to another generator in the plurality of generators by another electric bus in the plurality of electric buses.

[0013] Therefore, electrical isolation is proposed between a thruster connected to a generator by an electrical bus and another thruster of the same thrust point connected to another generator by another electrical bus.

[0014] Separation is - Avoiding the complexity of reconfiguring the network in flight via dynamic reconnection switches, given that high-voltage high-power switch technology is not yet mature enough to be used in flight; - Avoids the possibility of defects spreading after reconstruction, -Provides increased native redundancy without reconfiguration.

[0015] -Reducing development costs (dividing the power per train by 2), - Easier verification (less complexity since there is no reconfiguration), -Reduce the power / current of electrical equipment, making it possible.

[0016] According to one possibility, the generator comprises a turbo-alternator.

[0017] The generator may be thermal.

[0018] In one embodiment, the generator includes a fuel cell.

[0019] According to one possibility, at least one propellant bundle is dedicated to cruise propulsion.

[0020] According to a second possibility, optionally in combination with the first possibility, at least one propellant bundle is dedicated to generating a substantially vertical thrust.

[0021] According to a third possibility, optionally in combination with the first and / or second possibility, at least one propellant bundle is dedicated to generating the vectored thrust.

[0022] According to a fourth possibility, at least one propellant bundle is dedicated to generating a transverse thrust, optionally in combination with the first and / or second and / or third propellant bundles.

[0023] According to a second embodiment of the invention, an aircraft capable of hovering is proposed, equipped with a propulsion system according to the first embodiment, or one or more of its improvements.

[0024] According to a third aspect of the invention, a method is proposed for managing an electric propulsion system equipped on an aircraft capable of hovering according to the first aspect of the invention or one or more of its improvements, the aircraft comprising a propulsion management module receiving thrust commands for a propulsion point issued by a flight control module, the management module being configured on the one hand to transmit power request commands to each of the generators and on the other hand to transmit thrust commands to each of the thrusters of the propulsion point.

[0025] Advantageously, the method further comprises modifying the thrust commands sent to the thrusters of the propulsion point if a fault in a power generating unit or thruster is detected. [Brief description of the drawings]

[0026] Other advantages and particularities of the invention will become apparent upon reading the detailed description of embodiments and implementations, which is by no means exhaustive, with reference to the attached drawings, in which: [Figure 1] 1 shows a schematic perspective view from the starboard front of an airship according to the invention; [Diagram 2] FIG. 2 shows a schematic top view of the airship shown in FIG. 1. [Diagram 3] 3 shows a schematic detailed view of the system shown in FIG. 2. [Figure 4] 3 shows a schematic diagram of a connection method for the system shown in FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Since the embodiments described below are in no way limiting, it is particularly possible to consider a variant of the invention that includes only a selection of the described features, and then separates from the other features described, if the selection of features confers a technical advantage or is sufficient to distinguish the invention from the prior art, said selection including at least one feature, preferably functional, and not including structural details, or including only a part of the structural details, if only a part of the structural details confers a technical advantage or is sufficient to distinguish the invention from the prior art.

[0028] In the figures, elements that appear in several figures retain the same reference numbers.

[0029] Hovering aircraft Aircraft are divided into two main classes according to the means of lift used: aerobatic aircraft use static forces, while aerobatic aircraft generate dynamic forces to balance their weight. These aircraft are often designated as "lighter" or "heavy" than air.

[0030] The present invention relates to an aircraft capable of hovering.

[0031] A balloon-based airship is one example of such an aircraft, and includes a device intended to provide it with lift, and a propulsion system that gives it some maneuverability. For locomotion, the airship uses a propulsion system.

[0032] An aerated vehicle, ie, a "heavier than air" aircraft in which lift is provided primarily by aerodynamic forces, may be an aircraft capable of hovering.

[0033] This is the case, for example, when lift in an aerial vehicle is provided by electric motors with vectored thrust that have the ability to shift from a vertical thrust flight configuration to a horizontal thrust flight configuration during a transformation phase.

[0034] This is true even when lift for heavier aircraft is provided by rotors.

[0035] Additionally, some aerobatic vehicles have both fixed and rotary wings and have the ability to shift from a fixed-wing to a rotary-wing flying configuration during a conversion phase.

[0036] Thruster The thruster according to the invention is of the electric motor driven propeller type, the electric motor unit of course also comprising other elements such as a geared motor.

[0037] In this specification, the term thruster refers in particular to a static type of propulsion device having a horizontal and / or vertical component, and further to a propulsion device having vectored thrust, for example one that directs the exit flow by means of a steerable nozzle.

[0038] FIG. 1 shows an airship 1 having a roll axis in a longitudinal direction X, a pitch axis in a lateral direction Y, and a yaw axis in a vertical direction Z perpendicular to the longitudinal and lateral directions.

[0039] The airship 1 is equipped at the stern with two stabilizers, a starboard stabilizer 2 and a port stabilizer 3, each equipped with an elevator, and a tail vertical stabilizer 4 equipped with a rudder.

[0040] The airship 1 further comprises two lateral ailerons, respectively starboard aileron 5 and port aileron 6 (Figure 1).

[0041] The airship 1 is equipped with four generators G1, G2, G3, G4. In the example shown, the generators are of the turbo-alternator type, also called turbogenerators. According to a variant, the generators are electrically connected to fuel cells and / or batteries. Also, in the example shown, each of the four generators has a power of 1 MW.

[0042] In the illustrated example, the four generators G1, G2, G3, G4 are arranged inside the side ailerons 5 and 6. More specifically, turbo generators G1, G2 are arranged in the starboard aileron 5 and turbo generators G3, G4 are arranged in the starboard aileron 6.

[0043] In addition, in the illustrated example, the airship 1 is equipped with seven thrust points, PXt, PXb, PY, PZbt, PZbb, PZst, and PZsb, which enable the aircraft to hover and move.

[0044] The thrust points PXt and PXb are disposed so as to generate thrust in the longitudinal direction X toward the bow or stern. The thrust points PXt and PXb are disposed on the starboard and port sides of the airship 1.

[0045] More precisely, each of the thrust points PXt and PXb is connected to six thrusters of electric motor-driven propeller type Xt1, Xt2, Xt3, Xt4, Xt5, Xt6, respectively propellant bundles Xb1, Xb2, Xb3, Xb4, Xb5, Xb6. The propellers of each of the thrust points PXt and PXb are, for example, of the three-bladed propeller type.

[0046] These thrust points therefore make it possible to generate axial thrust forward or aft or yaw moments by differential thrust.

[0047] The propulsion point PY is arranged to generate a thrust in the lateral direction Y relative to the starboard or port side and generate a moment along the yaw axis. In the illustrated example, the propulsion point PY is arranged at the bow of the airship 1, at its upper side.

[0048] More precisely, the thrust point PY is a propellant bundle of four thrusters Y1, Y2, Y3, Y4 of the electric motor-driven propeller type, each of the propellers of the thrust point PY being, for example, of the three-bladed propeller type.

[0049] The thrust points PZbt and PZbb are arranged to generate thrust in a downward or upward direction Z. The thrust points PZbt and PZbb are arranged on the bow, starboard, and port sides of the airship 1.

[0050] Even more precisely, each of the thrust points PZbt and PZbb is a propellant bundle of four thrusters of electric motor-driven propeller type Zbt1, Zbt2, Zbt3, Zbt4, respectively Zbb1, Zbb2, Zbb3, Zbb4. The propellers of each of the thrusters of the thrust points Pzbt and PZbb are, for example, of the three-bladed propeller type.

[0051] The thrust points PZst and PZsb are arranged to generate thrust in a downward or upward direction Z. The thrust points PZst and PZsb are arranged at the stern, starboard, and port sides of the airship 1.

[0052] More precisely, each of the thrust points PZst and PZsb is a propellant bundle of four thrusters of electric motor-driven propeller type Zst1, Zst2, Zst3, Zst4, respectively Zsb1, Zsb2, Zsb3, Zsb4. The propellers of each of the thrusters of the thrust points Pzbt and PZbb are, for example, of the three-bladed propeller type.

[0053] Thus, the thrust points PZbt, PZbb, PZst and PZsb make it possible to generate an upward or downward vertical thrust, or a pitching moment due to the thrust difference between the bow and the stern, or a roll moment due to the thrust difference between the starboard and port sides.

[0054] As shown in FIG. 2, the airship 1 also includes four electric buses, bus 1, bus 2, bus 3, and bus 4, each having a power transport capacity of 1 MW.

[0055] Each electrical bus BUS1, BUS2, BUS3, BUS4 is connected to a turbine G1, G2, G3, G4 respectively by a system S1, S2, S3, S4 which will be described below.

[0056] Bus 1 is connected to electric motors Xt1, Xt3, Xb3, Y4, Zbt1, Zbb1, Zst1, Zsb1.

[0057] Bus 2 is connected to electric motors Xt4, Xb1, Xb4, Y3, Zbt2, Zbb2, Zst2, and Zsb2.

[0058] Bus 3 is connected to electric motors Xt2, Xt5, Xb5, Y5, Zbt3, Zbb3, Zst3, and Zsb3.

[0059] Bus 4 is connected to electric motors Xt6, Xb2, Xb6, Y1, Zbt4, Zbb4, Zst4, and Zsb4.

[0060] Next, the systems S1, S2, S3 and S4 will be described with reference to FIG.

[0061] System S1 is - Turbo generator G1; a rectifier R1 connected to a turbo-generator G1; a main power distribution unit (Main PDU1) connected to bus (Bus1); A battery HVBATT1 connected to a power distribution unit Main PDU1.

[0062] The main power unit Main PDU1 is also connected to a ground power unit GPU1.

[0063] System S2 is - Turbo generator G2; a rectifier R2 connected to a turbo-generator G2; a main power distribution unit (Main PDU2) connected to bus (Bus2); A battery HVBATT2 connected to the power distribution unit Main PDU2.

[0064] The main power unit Main PDU2 is also connected to a ground power unit GPU2.

[0065] Systems S1 and S2 are co-located on the port aileron 5.

[0066] System S3 is - Turbo generator G3, a rectifier R3 connected to a turbo-generator G3; a main power distribution unit (Main PDU3) connected to bus (Bus3); A battery HVBATT3 connected to the power distribution unit Main PDU3.

[0067] The main power unit Main PDU3 is also connected to a ground power unit GPU3.

[0068] System S4 is - Turbo generator G4, a rectifier R4 connected to a turbo-generator G4; a main power distribution unit (Main PDU4) connected to the bus (Bus4); A battery HVBATT4 connected to the power distribution unit Main PDU4.

[0069] The main power unit (Main PDU) 4 is also connected to a ground power unit (GPU) 4 .

[0070] Systems S3 and S4 are both installed on the starboard aileron 6.

[0071] Thus, as shown in FIG. 4, control of the flight of the airship 1 is ensured by a control unit Uc, which receives commands from the pilot, processes them and transmits them to a set of electric motors.

[0072] The electric motors are equipped separately with a unit for controlling the propeller pitch, which makes it possible to manage the thrust delivered. to electric motors Xt1, Xt2, Xt3, Xt4, Xt5, Xt6 at thrust point PXt via control units UcXt1, UcXt2, UcXt3, UcXt4, UcXt5, UcXt6, respectively; to the electric motors Xb1, Xb2, Xb3, Xb4, Xb5, Xb6 at the propulsion point PXb via the control units UcXb1, UcXb2, UcXb3, UcXb4, UcXb5, UcXb6, respectively; to the electric motors Y1, Y2, Y3, Y4 of the propulsion point PY via respective control units UcY1, UcY2, UcY3, UcY4, - to the electric motors Zbt1, Zbt2, Zbt3, Zbt4 of the propulsion point PZbt via the control units UcZbt1, UcZbt2, UcZbt3, UcZbt4, respectively; - to the electric motors Zbb1, Zbb2, Zbb3, Zbb4 of the propulsion point PZbb via the control units UcZbb1, UcZbb2, UcZbb3, UcZbb4, respectively; - to the electric motors Zst1, Zst2, Zst3, Zst4 of the propulsion point PZst via the control units UcZst1, UcZst2, UcZst3, UcZst4, respectively; -transmitted to the electric motors Zsb1, Zsb2, Zsb3, Zsb4 of the propulsion point PZsb via the control units UcZsb1, UcZsb2, UcZsb3, UcZsb4, respectively.

[0073] The control unit Uc distributes the demand from the pilot to all the electric motors. In case of failure of either the propulsion chain or the electric motor, this demand is distributed to the remaining functional units.

[0074] Each propulsion chain is controlled by a control unit Up1, Up2, Up3, Up4 respectively.

[0075] Each turbo generator is controlled by a generator control unit GCU1, GCU2, GCU3, GCU4 for generators G1, G2, G3, G4 respectively.

[0076] Each battery is controlled by a control unit BMS1, BMS2, BMS3, BMS4 (for "Battery Management System") for each battery HVBATT1, HVBATT2, HVBATT3, HVBATT4 respectively.

[0077] The control unit Up1 ensures the management of the power available on the bus 1. Depending on the total power of the electric motors Xt1, Xt3, Xb3, Y4, Zbt1, Zbb1, Zst1, Zsb1 provided by the bus 1, the unit Up1 controls the operating point of the turbogenerator G1 via the controller GCU1 and manages the charging or discharging of the battery HVBATT1 via the controller BMS1.

[0078] The control unit Up2 ensures the management of the power available on the bus 2. Depending on the total power of the electric motors Xt4, Xb1, Xb4, Y3, Zbt2, Zbb2, Zst2, Zsb2 supplied by the bus 2, the unit Up2 controls the operating point of the turbogenerator G2 via the controller GCU2 and manages the charging or discharging of the battery HVBATT2 via the controller BMS2.

[0079] The control unit Up3 ensures the management of the power available on the bus 3. Depending on the total power of the electric motors Xt2, Xt5, Xb5, Y5, Zbt3, Zbb3, Zst3, Zsb3 supplied by the bus 3, the unit Up3 controls the operating point of the turbogenerator G3 via the controller GCU3 and manages the charging or discharging of the battery HVBATT3 via the controller BMS3.

[0080] The control unit Up4 ensures the management of the power available on the bus 4. Depending on the total power of the electric motors Xt6, Xb2, Xb6, Y1, Zbt4, Zbb4, Zst4, Zsb4 provided by the bus 4, the unit Up4 controls the operating point of the turbogenerator G4 via the controller GCU4 and manages the charging or discharging of the battery HVBATT4 via the controller BMS4.

[0081] Thus, for each of the propulsion points, the thrusters of that propulsion point are electrically connected to one of the multiple generators by an electrical bus, and another thruster of that propulsion point is electrically connected to another of the multiple generators by another electrical bus.

[0082] It will be appreciated that for each thrust point that previously had a given thrust, if the turbogenerator stops working and that thrust point has four thrusters, each supplied by one turbogenerator independently of the others, the new thrust of the thrust point will be reduced by one-quarter of the previous thrust, and this loss of thrust may be compensated for by modifying the thrust of the other three thrusters of that thrust point.

[0083] Thus, when one generating unit has failed and another generating unit is operating normally, the control unit can generate commands targeted to the thrusters connected to the generating unit that is operating normally, and the thrusters can carry out the commands.

[0084] Similarly, if one thruster of a propulsion point stops working, and that propulsion point has four thrusters, each supplied independently of the others by a turbogenerator, the new thrust from the propulsion point will be reduced by one-quarter of the previous thrust, and this loss of thrust may be compensated for by modifying the thrust of the other three thrusters.

[0085] Thus, if one thruster at a propulsion point has failed and another thruster at that propulsion point is operating normally, the control unit can generate commands targeted to the normally operating thruster at that propulsion point, and that thruster can carry out the commands.

[0086] Naturally, the invention is not limited to the examples just described, and many modifications can be made to these examples without departing from the scope of the invention. In addition, the different features, forms, variations and embodiments of the invention may be associated with one another in various combinations, unless they are mutually incompatible or exclusive.

Claims

1. 1. A hovering airship equipped with an electric propulsion system, - Starboard stabilizer, port stabilizer and tail vertical stabilizer at the stern; - a number of generators (G1, G2, G3, G4); - a number of electric buses (bus 1, bus 2, bus 3, bus 4); a number of thrust points (PXt, PXb, PY, PZbt, PZbb, PZst, PZsb) located on the starboard and port sides, respectively; The plurality of propulsion points comprises at least one propulsion means formed of a plurality of electrically driven propeller-based thrusters dedicated to exerting longitudinal thrust, and at least one propulsion means formed of a plurality of electrically driven propeller-based thrusters dedicated to exerting vertical thrust, at least one of the longitudinal or vertical propulsion means is arranged such that each thruster in the propulsion means is electrically connected to a generator in the plurality of generators by an electrical bus (BUS 1, BUS 2, BUS 3, BUS 4) of the plurality of electrical buses, and each other thruster in the propulsion means is electrically connected to another generator in the plurality of generators by another electrical bus of the plurality of electrical buses; The airship capable of hovering, wherein the plurality of propulsion points further comprises at least one propulsion means (PY) dedicated to generating lateral thrust, the propulsion means (PY) being arranged such that one of its thrusters is electrically connected to a generator in the plurality of generators by an electric bus (Bus 1, Bus 2, Bus 3, Bus 4) of the plurality of electric buses, and each of at least one other thruster in the propulsion means is electrically connected to another generator in the plurality of generators by another electric bus of the plurality of electric buses.

2. Each propulsion station comprises a propulsion means formed from a plurality of electric propeller thrusters; 2. The airship of claim 1, wherein at each propulsion point, a thruster in the propulsion means is electrically connected to a generator in the plurality of generators by an electrical bus of the plurality of electrical buses, and each other thruster in the propulsion means is electrically connected to another generator in the plurality of generators by another electrical bus of the plurality of electrical buses.

3. 3. The airship of claim 1, wherein the generator comprises an AC generator.

4. The airship of claim 1 , wherein the generator includes a fuel cell.

5. 5. A method for managing an electric propulsion system on board an air vehicle capable of hovering as claimed in any one of claims 1 to 4, wherein the airship comprises a propulsion management module which receives thrust commands from a propulsion point issued by a flight control module, the management module being arranged on the one hand to transmit power request commands to each of the generators and on the other hand to transmit thrust commands to each of the thrusters of the propulsion point.

6. 6. The method of claim 5, further comprising modifying the thrust commands sent to the thrusters of the propulsion points when a fault in the plurality of generators (G1, G2, G3, G4) or thrusters is detected.

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