ELECTRIC DRIVE SYSTEM

Description

[0001] The present disclosure relates in particular to an electric drive system, a vehicle with such an electric drive system and a method for operating an electric drive system.

[0002] Electric drive systems are becoming increasingly important, and more and more vehicle types are being equipped with them, for example, bicycles, cars, and aircraft. These electric drive systems convert electrical energy into the vehicle's kinetic energy. In the case of aircraft, for example, the electric motor drives a propeller. The electrical energy is carried on board, for example, by a battery, supplied by a combustion engine with a generator, or generated in other ways, such as by solar cells.

[0003] In general, and in aircraft in particular, a very high level of reliability is regularly sought in electric drive systems, which is achieved, among other things, through redundant components. This ensures that a single fault does not lead to the failure of the entire electric drive system, as the faulty component or assembly is electrically and / or mechanically isolated from the rest of the electric drive system, while the rest of the electric drive system remains functional.

[0004] In practice, electric motors with multiple electrically isolated lanes are used for this purpose. Such an electric motor can also be called a multi-lane electric motor. The electric motor thus comprises several sub-motors whose wire windings are galvanically isolated from one another. All sub-motors of the electric motor drive the same rotor. If, for example, a short circuit occurs in the wire winding of one of the lanes, it can be electrically disconnected from the drive power supply, while the remaining lanes continue to generate feed.

[0005] However, such multi-lane concepts often also entail increased complexity of the corresponding electric drive system.

[0006] US Patent 11,065,979 B1 describes a monitoring system for an electric or hybrid aircraft. It proposes driving a motor via a first set of motor windings using a battery pack, and generating energy with a second set of motor windings acting as a generator.

[0007] EP 3 620 382 A1 concerns the operation of a hybrid aircraft propulsion system. It describes how two motors can each have two stators, with one stator being operated via a generator, while the other stator is supplied with energy from a battery via an inverter.

[0008] Further hybrid-electric propulsion systems are described in US 2021 / 221526 A1 and US 2020 / 290742 A1. US 2020 / 017197 A1 describes a spring setting for propeller blades.

[0009] The object of the present invention is to enable high performance with the simplest possible design of an electric drive system.

[0010] This task is solved by the electric drive system and the independent claims procedure.

[0011] This utilizes the multi-lane concept of the electric motor to exchange electrical energy between electrically isolated lanes (and, if applicable, the electrically isolated energy sources connected to each lane). This enables a significant improvement in performance while simultaneously increasing reliability and, thanks to the dual benefits of the multi-lane electric motor, a simple design and low weight. Furthermore, it allows for a wide range of applications, which are detailed herein. A lane can also be described as a current path arrangement. In a three-phase alternating current, for example, each lane comprises electrical conductors for all three phases. These conductors are electrically isolated from the conductors of the other lanes of the electric motor.

[0012] The rotor is coupled, for example, to a turbomachine, such as a propeller, a fan, or a compressor, particularly in an aircraft. The advantages described above are especially pronounced in aircraft.

[0013] In one embodiment, the turbomachine has rotor blades with adjustable angles of attack, and the control system can be configured to adjust the angles of attack of the rotor blades during simultaneous motor and generator operation so that the turbomachine does not generate thrust. This allows, for example, energy to be transferred between lanes when the aircraft is stationary.

[0014] Each lane comprises, or consists of, an electrical winding system. The winding system includes at least one wire winding. The wire winding(s) is / are formed, for example, from a wire wound multiple times, e.g., around a tooth.

[0015] Each power supply unit includes, for example, an inverter and / or can be operated as an inverter. A direct current applied to the respective power supply unit can thus be converted into an alternating current for the electric motor. In particular, the power supply units can each be configured to convert a direct current into a three-phase alternating current and supply it to the corresponding lane. Each lane is therefore, for example, configured to be operated with a three-phase alternating current to set the rotor in motion.

[0016] Furthermore, at least one (or, for example, all) of the power supply units can include a rectifier and / or be operable as a rectifier. Thus, the power supply unit can be supplied with alternating current from the respective lane to generate direct current, which can then be supplied to an energy storage device to store electrical energy. The power supply unit(s) is / are, for example, each designed to convert three-phase alternating current from the corresponding lane into direct current. This makes it possible to transfer energy via the electric motor between electrically isolated (and independent) DC lanes using the electric drive system, without the need for additional components such as DC / DC converters or additional switches. One or each of the power supply units can be operated as both an inverter and a rectifier.For example, the control system can selectively control the power supply unit(s) so that they act either as an inverter or as a rectifier. The inverter and the rectifier in the power supply unit(s) are implemented using the same hardware, such as the same switches, transistors, or similar components.

[0017] The electric drive system also includes a generator electrically connected to at least one of the lanes. The generator is mechanically coupled to an internal combustion engine. Such a generator can be used, for example, to extend the vehicle's range. The design of the electric drive system allows, for instance, only some of the lanes to be connected to the generator, with energy supplied by the generator being transferable to the other lanes via simultaneous engine and generator operation. This eliminates the need for some cable connections, resulting in reduced weight and less wiring.

[0018] The generator can comprise several electrically isolated lanes, in which an electrical voltage is induced by the rotation of a generator rotor. Each lane of the generator is electrically connected to, for example, only one lane of the electric motor. This enables a particularly high level of reliability.

[0019] Optionally, the electric drive system includes a second electric motor, also with a rotor and several electrically isolated lanes that can be independently powered to drive the rotor of the second electric motor. This allows sufficient thrust to be generated even for larger vehicles.

[0020] In one embodiment, at least one lane of the electric motor is electrically connected to at least one lane of the generator, while at least one lane of the second electric motor is electrically connected to at least one other lane of the generator. This allows both electric motors to be supplied with power by the generator.

[0021] The electric drive system also includes, for example, an energy storage device electrically connected to at least one of the lanes. This allows, for example, the partial or complete elimination of fossil fuels.

[0022] Optionally, the electric drive system includes several energy storage devices, each electrically connected to at least (or exactly) one of the lanes. It can be provided that electrical energy can be transferred from one of the energy storage devices to another energy storage device via a lane operating in motor mode and another lane operating in generator mode.

[0023] According to one aspect, a vehicle, e.g., an aircraft, in particular an airplane, a rotorcraft, or an unmanned aerial vehicle, a land vehicle, in particular a bus or a truck, or a watercraft, is provided. The vehicle includes the electric drive system according to any configuration described herein, in particular for driving a thrust-generating device, e.g., a propeller. The advantages of the electric drive system described herein are particularly evident in a vehicle, especially an aircraft.

[0024] The vehicle can have at least one energy storage device electrically connected to at least one of the lanes and mounted on the vehicle in a replaceable manner. For this purpose, the vehicle includes, for example, a corresponding connector. Alternatively or additionally, at least one energy storage device electrically connected to at least one of the lanes can be permanently mounted on the vehicle. For example, the permanently mounted energy storage devices serve as a reserve, and the replaceable energy storage device serves as the primary energy source. In a less than fully utilized operating state, such as during a glide, descent, or taxiing flight in an aircraft, energy can be exchanged between the energy storage devices via the electric motor. This allows, for example, the permanently installed energy storage device to be fully charged with residual energy from the replaceable energy storage device before the latter is replaced.

[0025] The vehicle can be designed as an aircraft with a fuselage and wings, wherein, for example, at least one energy storage device electrically connected to at least one of the lanes is mounted on or in the fuselage (in particular, replaceable) and at least one energy storage device electrically connected to at least one of the lanes is mounted on or in one of the wings (in particular, fixed).

[0026] According to claim 14, a method for operating an electric drive system is specified, in particular a drive system according to any embodiment described herein.

[0027] Exemplary embodiments are now described with reference to the figures, which show: Figure 1 is a schematic sectional view of an electric drive system with a permanent magnet, three-phase electric motor as an internal rotor; Figure 2 is a schematic block diagram of an electric drive system with two electric motors, a separate generator, and several energy storage devices; Figure 3 is a schematic block diagram of an electric drive system with two electric motors and several energy storage devices, some of which are combined in an electrical energy storage system that is not part of the invention; Figure 4 is a schematic block diagram of an electric drive system with two electric motors connected to a common energy storage system that is not part of the invention; and Figure 5 is a schematic representation of an aircraft in the form of an airplane.

[0028] Figure 1Figure 1 shows a schematic sectional view of an electric drive system 1A with an electric motor 10 in the form of a permanent magnet synchronous machine. Figure 1 It is evident that the electric motor 10 is designed as an internal rotor. The electric motor 10 comprises an assembly in the form of a stator 103, which has an undesignated opening, in particular a through-opening, in which a further assembly in the form of a rotor 100 is rotatably mounted.

[0029] The stator 103 comprises a body in the form of a laminated core, to which teeth, also known as stator teeth, are attached. The stator teeth are aligned with an air gap L between the body of the stator 103 and the rotor 100. The stator teeth project radially from the body, in this case radially inwards.

[0030] The electric motor 10 further comprises several (here two) electrically isolated lanes 101A, 101B, which can be supplied with electrical current independently of each other to drive the rotor 100. Each lane 101A, 101B forms a partial motor or sub-motor that can be operated independently of the others.

[0031] Each of the lanes 101A and 101B has a winding system comprising several wire windings D. The wire windings D are wound around the stator teeth. The winding systems are designed for three-phase operation, meaning they are connected to a three-phase AC voltage with phases U, V, and W. During normal operation of the electric drive system 1A, the winding systems can be supplied with the AC voltage. The winding systems of all lanes 101A and 101B are fixed to the same stator 103.

[0032] Lanes 101A and 101B are galvanically isolated from each other. The rotor 100 can be set into rotation relative to the stator 103 by applying the alternating voltage to any one of lanes 101A or 101B, as well as by applying the alternating voltage to all lanes 101A and 101B.

[0033] The rotor 100 is shown here as an example of a salient-pole rotor, which includes permanent magnets to provide the magnetic flux. In the present embodiment, the rotor 100 has exactly one magnetic north pole N and one magnetic south pole S. In alternative embodiments, more magnetic poles can also be provided in an alternating circumferential direction transverse to an axis of rotation of the rotor 100 (relative to the stator 103).

[0034] The rotor 100 is rotatably mounted. A rotating magnetic field is generated by one or both lanes 101A and 101B during normal operation by the three-phase alternating voltage, whose phases U, V, and W are each phase-shifted by 120°. This rotating magnetic field interacts with the permanent magnet magnetic field provided by the rotor 100, so that, in motor operation of lane(s) 101A and 101B, a corresponding rotational movement of the rotor 100 relative to the stator 103 can be achieved. The electric motor 10 is intended to serve as a drive motor for an aircraft propeller, as will be explained in more detail below. Figure 1 The sections of the winding systems that are assigned to the respective phases U, V, W are shown schematically.

[0035] Furthermore, lanes 101A, 101B can be operated in generator mode, in which electrical current is provided by the respective lane 101A, 101B to convert mechanical energy of the rotor 100 into electrical energy.

[0036] The two lanes 101A, 101B of the electric motor 10 are each connected to one of two independent supply units 11, each of which is three-phase.

[0037] The power supply units 11 are switchable between inverter and rectifier operation (or at least this applies to one of the power supply units 11). In inverter operation, the respective power supply unit 11 generates the alternating voltage for the corresponding lane 101A, 101B from a direct current voltage. In rectifier operation, the respective power supply unit 11 generates a direct current voltage from the alternating voltage generated in the corresponding lane 101A, 101B by the rotation of the rotor 100. In inverter operation, in one possible embodiment, (at least some of) the same electrical and / or electronic components of the respective power supply unit 11 are active as in rectifier operation.

[0038] A control system 12 of the electric drive system 1A is operationally connected to the supply units 11 and selectively switches them to inverter or rectifier operation. The control system 12 is thus configured to operate one of the lanes 101A, 101B in motor mode by supplying the lane 101A, 101B with alternating current via the corresponding supply unit 11 to convert electrical energy into kinetic energy of the rotor 100, and (e.g., simultaneously) to operate at least one other of the lanes 101A, 101B in generator mode by supplying alternating current from the lane 101A, 101B to the corresponding supply unit 11 and direct current through it to convert kinetic energy of the rotor 100 into electrical energy.

[0039] The power supply units 11 provide the alternating current with the three phases U, V, W. The power supply units 11 draw the electrical energy required for their intended operation from an energy source connected to one of the two power supply units 11 via an electrical connection 17, in this case, an energy storage device 15. The individual electrical connections 17 can also be referred to as DC lanes (or as a DC bus). The energy storage devices 15 (generally the energy sources) are electrically isolated from one another and can be operated independently. In the present embodiment, each energy source is a DC voltage source that provides electrical energy, for example, from a rechargeable battery. Alternatively or additionally, fuel cells and / or the like can be provided.

[0040] To generate the alternating current from the direct current, the power supply units 11 each include an inverter 110. The inverters 110 each have, for example, a full bridge circuit for providing the phases U, V, W. In particular, the inverters 110 can each have at least one series connection of two electronic switching elements (e.g., transistors) connected to the respective direct current of the power source. The electronic switching elements are operated in clock mode by means of a control unit of the respective inverter 110, which provides, for example, clock patterns similar to a PWM signal.

[0041] Furthermore, each of the supply units 11 includes a rectifier 111. By means of the rectifier 111, the respective supply unit 11 can rectify an alternating current induced by a rotation of the rotor 100 in the connected lane 101A, 101B and provide it as direct current to the corresponding energy storage device 15.

[0042] In inverter mode, inverter 110 is activated and rectifier 111 is deactivated. In rectifier mode, the inverter is deactivated and the rectifier is activated.

[0043] If one of the lanes 101A, 101B is simultaneously operated in motor mode and the other in generator mode, energy transfer between the galvanically isolated DC lanes and, in particular, the energy storage devices 15 is possible. If the pitch of rotor blades mounted on and / or rotating on the rotor 100 is adjusted so that no thrust is generated, this can even be done, for example, when the aircraft is stationary.

[0044] The control system 12 can include a central control unit and / or several distributed control units, e.g. one control unit in each of the supply units 11.

[0045] For the sake of simplicity, the supply units 11 are counted here as part of the electric drive system 1A, but can also be considered as part of the respective connected lanes 101A, 101B.

[0046] Figure 2Figure 1B shows an electric drive system 1B for a vehicle, in particular an aircraft, with two electric motors 10A, 10B. Each of the electric motors 10A, 10B drives a turbomachine 102 in the form of a propeller via a rotor 100.

[0047] The electric motors 10A and 10B each comprise several, specifically four separate, lanes 101A-101D. The respective propeller can be driven by any of the lanes 101A-101D, meaning it will rotate when at least one of the lanes 101A-101D is energized. The lanes of each electric motor 10A and 10B are electrically isolated from one another.

[0048] Each of the lanes 101A-101D of the electric motors 10A, 10B is connected to a power supply unit 11 via a corresponding electrical connection 17. The power supply units 11 are designed, for example, as in connection with Figure 1explained. The supply units 11 allow at least one of the lanes 101A-101D to be operated simultaneously in motor mode, in which the lane 101A-101D is supplied with electric current via the corresponding supply unit 11 to convert electrical energy into kinetic energy of the rotor 100, and at least one of the lanes 101A-101D to be operated in generator mode, in which electric current is provided by means of the lane 101A-101D via the corresponding supply unit 11 to convert kinetic energy of the rotor 100 into electrical energy.

[0049] Each of the electric motors 10A, 10B together with the connected supply units 11 forms an electric drive unit EPU, in this case for the respective turbomachine 102.

[0050] The electric drive system 1B further comprises an internal combustion engine 14, e.g., in the form of an auxiliary power unit (APU) with a compressor and a turbine. The internal combustion engine 14 drives a generator 13. The generator 13 comprises several, here four, lanes 131A-131D. Each of the lanes 131A-131D is electrically connected to (only) exactly one respective power supply unit 11 via a corresponding electrical connection 17 and is electrically connected via this power supply unit 11 to (only) exactly one lane 101A-101D of one or the other electric motor 10A, 10B.

[0051] Furthermore, the electric drive system 1B includes an electric energy storage system ESS. The electric energy storage system ESS comprises several energy storage devices 15. The individual energy storage devices 15 of the electric energy storage system ESS are electrically isolated from one another. In this case, the energy storage devices 15 are each designed in the form of a rechargeable battery.

[0052] Each of the energy storage units 15 is connected to (only) exactly one supply unit 11 via an electrical connection 17 and is electrically connected via this supply unit 11 to (only) exactly one lane 101A-101D of one or the other electric motor 10A, 10B.

[0053] Specifically, several, namely exactly two, lanes 101A, 101B from each of the two electric motors 10A, 10B (via their respective supply units 11) are electrically connected to one of the several, namely exactly four, energy storage devices 15. The remaining, specifically also exactly two, lanes 101C, 101D from each of the two electric motors 10A, 10B are electrically connected (via their respective supply units 11) to one of the several, namely exactly four, lanes 131A-131D of the generator 13. More generally, at least one of the lanes 101A, 101B from an electric motor 10A, 10B of the electric drive system 1B is electrically connected to the generator 13, and at least one other of the lanes 101C, 101D of the electric motor 10A, 10B is electrically connected to the Electrical Energy Storage System (ESS).This prevents limitations in the operation of generator 13 caused by fluctuating battery voltages.

[0054] At least lanes 101A and 101B, which are electrically connected to one of the energy storage units 15, can be operated either as a motor or as a generator. For this purpose, the respective supply units 11 can be switched, for example, between inverter and rectifier operation, as described above.

[0055] Optional switches 16 in the electrical connections 17 can be opened and closed to disconnect one of the connected components, e.g. in case of a component failure or during non-use.

[0056] In Figure 2An example usage scenario is illustrated by arrows in which only one of the two propellers is set in motion, optionally with an angle of attack at which the propeller does not generate thrust. The combustion engine 14 drives the generator 13, inducing voltages in its lanes 131A-131D. These voltages are applied via the supply units 11 and the closed switches 16 to the lanes 101C, 101D of one electric motor 10A, resulting in a current flow that generates an alternating magnetic field, which in turn sets the rotor 100 in motion. This induces voltages in the remaining two lanes 101A, 101B of the electric motor 10A, which, via the corresponding supply units 11, result in a charging current for the respective energy storage devices 15.Thus, despite galvanic isolation from the energy storage devices 15, the generator 13 can charge the energy storage devices 15 via the electric motor 10A.

[0057] Optionally, the other electric motor 10B is operated analogously by the control system 12 controlling the switches 16 and the supply units 11 accordingly.

[0058] The control system 12 determines the positions of the switches 16 and the setting of the supply units 11 to generator operation or motor operation.

[0059] Figure 3 Figure 1C shows an electric drive system for a vehicle, in particular an aircraft, with two electric motors 10A, 10B, which are accordingly Figure 2 They are constructed differently, but connected differently.

[0060] The electric drive system 1C according to Figure 3It does not include an internal combustion engine with a generator. All lanes 101A-101D of the electric motors 10A, 10B are connected (exclusively) to energy storage devices 15 via the respective supply units 11. The energy storage devices 15 are each designed in the form of a rechargeable battery.

[0061] For each lane 101A-101D of each of the electric motors 10A, 10B, exactly one energy storage device 15 is provided; in the case of eight lanes 101A-101D as an example, there are eight energy storage devices 15.

[0062] In the example shown, several of the energy storage units 15 are combined to form an electrical energy storage system (ESS). This electrical energy storage system (ESS) is installed on the vehicle and can be detached and replaced non-destructively (e.g., via appropriate connectors). The electrical energy storage system (ESS) serves as the primary energy source. If the electrical energy storage system (ESS) has a low charge level, it can be quickly replaced with a fully charged electrical energy storage system (ESS) and thus does not need to be charged on the vehicle, which would typically be considerably more time-consuming. The energy storage units 15 of the electrical energy storage system (ESS) are mounted, for example, in a common housing or on a common support frame.

[0063] Two additional energy storage devices 15 are arranged separately from the electrical energy storage system ESS and are, for example, permanently attached to the vehicle. These energy storage devices 15 serve, for example, to maintain an energy reserve and / or to provide additional energy during maximum power consumption, such as during the takeoff of the aircraft-style vehicle. In particular, the energy transfer via the electric motors 10A, 10B also makes it possible to provide such reserve energy storage devices 15 without requiring additional DC / DC converters or the like for their connection.

[0064] The separate energy storage units 15, as illustrated by the arrows, can be charged via the corresponding electric motors 10A and 10B by supplying energy from the electrical energy storage system ESS to the other three lanes 101B-101D. This can occur, for example, during gliding flight or on the runway, or, in the case of a car or bus, during a journey that is not fully loaded.

[0065] Figure 4 Figure 1D shows an electric drive system for a vehicle, in particular an aircraft, with two electric motors 10A, 10B, which are accordingly Figure 2 and 3 They are constructed differently, but connected differently.

[0066] The electric drive system 1D according to Figure 4This example does not include an internal combustion engine or a separate generator. All lanes 101A-101D of the electric motors 10A and 10B are connected (exclusively) to energy storage devices 15 via their respective supply units 11. The energy storage devices 15 are, for example, each designed as a rechargeable battery.

[0067] For each lane 101A-101D of one electric motor 10A and one lane 101A-101D of the other electric motor 10B, exactly one common energy storage device 15 is provided; with a total of eight lanes 101A-101D in this example, there are therefore four energy storage devices 15. The electrical connection 17 from each of the energy storage devices 15 to the supply units 11 of the two associated lanes 101A-101D thus has a branch 170.

[0068] This circuit makes it possible, in the event of a fault on one of the lanes 101A-101D, to switch off this lane 101A-101D and to distribute the energy not called up by this lane 101A-101D via the other electric motor 10A, 10B in such a way that both electric motors 10A, 10B generate the same thrust and / or all energy storage devices 15 are discharged equally.

[0069] In the example shown, a fault has occurred in the power supply unit 11 of the fourth lane 101D of one electric motor 10A. The control system 12 has disconnected this power supply unit 11 from the corresponding energy storage device 15 via the associated switch 16. The remaining lanes 101A-101C of electric motor 10A continue to operate. Due to the fault, lane 101A of the other electric motor 10B, which is connected to the faulty power supply unit 11 via the corresponding branch 170, now consumes the energy of its associated energy storage device 15 alone. Without energy being transferred to the other lanes 101A-101D, this energy storage device 15 would therefore be depleted only half as fast as the other energy storage devices 15, leaving unused energy and thus reducing the range.

[0070] The described design of the electric drive system 1D makes it possible to operate the remaining lane 101A of this energy storage device 15 with a higher current and / or to operate one or more of the other lanes 101B-101D of this electric motor 10B, at least temporarily, in generator mode. The energy supplied in this way can be provided to the remaining lanes 101A-101C of the electric motor 10A. Optionally, the remaining energy storage devices 15 are decoupled, at least temporarily, by opening the associated switches 16. Alternatively, the switches 16 of the energy storage devices 15 are closed, and, for example, the switches 16 of the remaining lanes 101A-101C of the electric motor 10A are opened. This allows the remaining energy storage devices 15 to be charged.

[0071] Figure 5Figure 2 shows a vehicle, specifically an aircraft 2 in the form of an electrically powered airplane. The aircraft 2 comprises a fuselage 21 with wings 22 attached to it. An engine 20 is mounted on each of the wings 22. The aircraft 2 further comprises one of the electric propulsion systems 1A-1D described herein, for example, the electric propulsion system 1C according to [reference to relevant figure]. Figure 3 The electrical energy storage system (ESS) is interchangeably arranged in the fuselage 21, while further energy storage units 15 of the electric propulsion system 1C are permanently mounted in the wings. The engines 20 each comprise one of the electric motors 10A, 10B, with the turbomachines 102 each configured as a fan, so that the electric motors 10A, 10B of the electric propulsion system 1C can generate thrust to propel the aircraft 2. Reference symbol list

[0072] 1A-1D Electric drive system 10; 10A, 10B Electric motor 100 Rotor 101A-101D Lane 102 Turbomachine 103 Stator 104 Stator tooth 11 Power supply unit 110 Inverter 111 Rectifier 12 Control system 13 Generator 14 Internal combustion engine 15 Energy storage 16 Switch 17 Electrical connection 170 Branch 2 Aircraft 20 Engine 21 Fuselage 22 Wing D Wire winding EPU Electric drive unit ESS Electric energy storage system L Air gap N North pole S South pole U, V, W Phase

Claims

1. Electric propulsion system (1A-1D) comprising: - an electric motor (10; 10A, 10B) having a rotor (100) and a plurality of lanes (101A-101D) which are electrically separated from one another and which can be supplied with electrical current independently of one another in order to drive the rotor (100),wherein each of the lanes (101A-101D) comprises a winding system with at least one wire winding (D); - a respective supply unit (11) for each of the lanes (101A-101D); and - a control system (12) that is configured to simultaneously operate at least one of the lanes (101A-101D) in a motor mode, in which electrical current is applied to the lane (101A-101D) via the corresponding supply unit (11) in order to convert electrical energy into kinetic energy of the rotor (100), and to operate at least one of the lanes (101A-101D) in a generator mode, in which electrical current is supplied via the corresponding supply unit (11) via the lane (101A-101D); characterized in that a generator (13) which is functionally electrically connected to at least one of the lanes (101A-101D) via a further supply unit (11) and which is mechanically coupled to an internal combustion engine (14), wherein the further supply unit (11) comprises a rectifier (111).

2. Electric propulsion system (1A-1D) according to claim 1, wherein the rotor (100) is coupled to a turbomachine (102), in particular a propeller, a fan or a compressor.

3. Electric propulsion system (1A-1D) according to claim 2, wherein the turbomachine (102) has rotor blades with adjustable angles, wherein the control system (12) is configured to adjust the angles of the rotor blades in a simultaneous motor and generator mode such that the turbomachine (102) does not generate propulsion.

4. Electric propulsion system (1A-1D) according to one of the preceding claims, wherein each supply unit (11) comprises an inverter (110) and / or is operable as an inverter, wherein the supply units (11) are each designed to convert a direct current into a three-phase alternating current and to supply it to the corresponding lane (101A-101D).

5. Electric propulsion system (1A-1D) according to one of the preceding claims, wherein one or each of the supply units (11) comprises a rectifier (111) and / or can be operated as a rectifier, wherein one or each of the supply units (11) is / are respectively designed to convert a three-phase alternating current from the corresponding lane (101A- 101D) into a direct current.

6. Electric propulsion system (1A-1D) according to claim 1, wherein the generator (13) comprises a plurality of electrically separated lanes (141A-141D).

7. Electric propulsion system (1A-1D) according to one of the preceding claims, further comprising a further electric motor (10B) having a rotor (100) and a plurality of lanes (101A-101D) which are electrically separated from one another and which can be supplied with electrical current independently of one another in order to drive the rotor (100).

8. Electric propulsion system (1A-1D) according to claim 6 and according to claim 7, wherein at least one lane (101C, 101D) of the electric motor (10A) is functionally electrically connected to at least one lane (131A, 131B) of the generator (13) and at least one lane (101C, 101D) of the further electric motor (10B) is functionally electrically connected to at least one further lane (131C, 131D) of the generator (13).

9. Electric propulsion system (1A-1D) according to one of the preceding claims, further comprising an energy store (15) electrically connected to at least one of the lanes (101A-101D).

10. Electric propulsion system (1A-1D) according to one of the preceding claims, further comprising a plurality of energy stores (15), each electrically connected to at least one of the lanes (101A-101D), wherein electrical energy can be transferred from one of the energy stores (15) to another energy store (15) via a lane (101A-101D) operated in motor mode and a lane (101A-101D) operated in generator mode.

11. Vehicle, in particular aircraft (2), comprising the electric propulsion system (1A-1D) according to one of the preceding claims.

12. Vehicle according to claim 11, wherein at least one energy store (15) electrically connected to at least one of the lanes (101A-101D) is replaceably mounted on the vehicle via plug connectors, and at least one energy store (15) electrically connected to at least one of the lanes (101A-101D) is fixedly mounted on the vehicle.

13. Vehicle according to claim 11 or 12, wherein the vehicle is designed as an aircraft (2) with a fuselage (21) and wings (22), and at least one energy store (15) electrically connected to at least one of the lanes (101A-101D) is mounted on or in the fuselage (21), and at least one energy store (15) electrically connected to at least one of the lanes (101A-101D) is mounted on or in one of the wings (22).

14. Method for operating an electric propulsion system (1A-1D), in particular according to one of claims 1-10, comprising an electric motor (10; 10A, 10B) with a rotor (100) and a plurality of lanes (101A-101D) which are electrically separated from one another and which can be supplied with electrical current independently of one another in order to drive the rotor (100), wherein each of the lanes (101A-101D) comprises a winding system with at least one wire winding (D), and in each case a supply unit (11) for each lane (101A-101D) of the at least one electric motor (10), wherein at least one of the lanes (101A-101D) is simultaneously operated in a motor mode, wherein the lane (101A-101D) is supplied with electrical current via the corresponding supply unit (11) in order to convert electrical energy into kinetic energy of the rotor (100), and at least one of the lanes (101A-101D) is operated in a generator mode in which electrical current is supplied by the lane (101A-101D) via the corresponding supply unit (11), characterized in that a generator (13) functionally electrically connected to at least one of the lanes (101A-101D) via a further supply unit (11) is mechanically coupled to an internal combustion engine (14), wherein the further supply unit (11) is operated as a rectifier.