Hybrid electrical architecture

Abstract

A hybrid power distribution system for an aircraft includes a first set of electrically powered devices and a second set of electrically powered devices, such as inverters, motors, etc. A first battery system is coupled to one or more of the first set of electrical devices, and a first fuel cell is coupled to one or more of the first set of electrical devices. A second battery system is coupled to one or more of the second set of electrically powered devices, and a second fuel cell is coupled to one or more of the second set of electrically powered devices. The fuel cell and the battery together supply power to the electrically powered device as needed, while the fuel cell also keeps the battery charged.

Description

[0001] Related Application Data

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 383,659, filed on November 14, 2022, the content of which is incorporated herein as if set forth in full.

[0003] Field of Disclosure

[0004] The subject matter relates to hybrid electric architectures. More specifically but not exclusively, the present disclosure relates to hybrid electric architectures that include a battery and a fuel cell system to provide power for an aircraft.

[0005] Background

[0006] There is currently a push to transition away from internal combustion engines, turbines, and other fossil fuel-based propulsion methods. The push towards the use of electricity and batteries may be limited because the energy density of current batteries is less than that of a fuel tank that holds the same volume of fossil fuel. In other words, a battery of the same size as a gasoline tank may not have the energy storage capacity to propel a vehicle the same distance. Field of Technology

[0007] The present invention generally relates to the field of aviation and, more specifically, to hybrid architectures for electric aircraft.

[0008] A fuel cell is an electrochemical cell that converts the chemical energy of a fuel (usually hydrogen) and an oxidant (usually oxygen) into electrical energy through a pair of redox reactions. Fuel cells have been used to generate electricity in many applications. Fuel cells are used as primary and backup power sources in commercial, industrial, and residential buildings, as well as in remote or hard-to-reach areas. They are also used to power fuel cell vehicles, which include forklifts, cars, buses, trains, boats, motorcycles, and submarines.

[0009] Fuel cell vehicles are powered by hydrogen, which is fed into an on-board fuel cell "stack" that converts the chemical energy of the hydrogen into electrical energy. This electrical energy can then be used to power the vehicle and its on-board systems.

[0010] The hydrogen supplied to the fuel cell enters the anode, where it contacts a catalyst that promotes the separation of hydrogen atoms into electrons and protons. The electrons are collected by a conductive current collector that is connected to the vehicle's high-voltage circuit to power the on-board battery and / or electric motor that propels the vehicle. The by-product of the reaction that occurs in the fuel cell stack is water vapor, which is discharged through an exhaust.

[0011] Fuel cell powered vehicles also include a "balance-of-plant", which includes all other components of the fuel cell system except the fuel cell stack itself. This includes pumps, sensors, heat exchangers, gaskets, compressors, recirculation blowers, or humidifiers, etc. Brief Description of the Drawings

[0013] In the drawings, which are not necessarily to scale, like numerals may describe like components in different views. Like numerals with different letter suffixes may represent different instances of like components. The drawings illustrate, by way of example and not limitation, various examples discussed in this document.

[0014] Figure 1 is a plan view of an aircraft according to some examples.

[0015] Figure 2 is according to some examples for Figure 1 the aircraft energy system in an aircraft.

[0016] Figure 3 is according to some examples for Figure 1 the aircraft energy system in an aircraft.

[0017] Figure 4 shows a schematic diagram of a hydrogen fuel cell system for an aircraft according to some examples for Figure 1 the aircraft.

[0018] Figure 5 shows an aircraft with a hybrid electrical architecture system according to some examples.

[0019] Figure 6 shows an aircraft with a hybrid electrical architecture system according to some examples.

[0020] Figure 7 shows an aircraft with a hybrid electrical architecture system according to some examples.

[0021] Figure 8A is a perspective view of an aircraft in a vertical thrust configuration according to some examples.

[0022] Figure 8B is a perspective view of an aircraft in a horizontal thrust configuration according to some examples.

[0023] Figure 9A , Figure 9B and Figure 9C show the tilt of an aircraft propulsion system and related components (such as a propeller and a nacelle) according to some examples.

[0024] Figure 10A , Figure 10B and Figure 10C illustrate the tilting of an aircraft propulsion system and associated components (such as a propeller and nacelle) according to some examples.

[0025] Figure 11 is a flow chart illustrating a method of providing power to a propulsion system of an aircraft according to some examples.

[0026] Figure 12 illustrates a graphical representation of a machine in the form of a computer system within which a set of instructions can be executed to cause the machine to perform any one or more of the methods discussed herein.

[0027] Detailed Description

[0028] Aircraft and other vehicles can utilize battery technology for propulsion rather than burning fossil fuels. For example, aircraft and automobiles can use electric motors for propulsion, and batteries can be used for energy storage. Electric motors offer the benefit that they are quieter compared to internal combustion engines or turbines. Additionally, batteries can increase or decrease power delivery in response to a rapid increase or decrease in the electrical load.

[0029] Due to the lower energy density of batteries compared to fossil fuels, aircraft and other vehicles that utilize battery technology for propulsion rather than burning fossil fuels may have range limitations. In other words, given the size and weight limitations imposed on the batteries, compared to a fuel tank of the same volume, the batteries may only contain enough energy for a short trip.

[0030] Fuel cell systems (such as hydrogen fuel cell systems) can be used to power electrical components. However, fuel cell systems may have limitations because they cannot rapidly increase or decrease the supplied power in view of changes in the load on the electrical components. For example, an electric motor that is commanded to rapidly increase power may exceed the power response rate of the fuel cell system.

[0031] As disclosed herein, batteries can be used to power electric devices such as electric motors, and fuel cell systems can be used to keep the batteries charged during a journey. The batteries can supply a constant or near-constant voltage to the electrical components while also being able to sufficiently supply power due to current spikes that may be caused by an increase in the load on the electrical components.

[0032] Consistent with the examples disclosed herein, a battery can be used to power electrical components, and a fuel cell system can also be used to power electrical components and to keep the battery charged. The fuel cell system can be a hydrogen fuel cell system. Compared to a battery alone, hydrogen can have an increased energy density. Thus, hydrogen gas stored in a tank can provide more energy than a battery of comparable mass and / or volume. As a result, a vehicle such as an aircraft can have increased range and availability because a smaller battery can be used to power electrical devices while the fuel cell system recharges the smaller battery.

[0033] The foregoing discussion is intended to provide an overview of the subject matter of this patent application. It is not intended to provide an exclusive or exhaustive interpretation of the invention. The following description is included to provide additional information regarding this patent application.

[0034] Figure 1 is a plan view of an aircraft 100. The aircraft 100 includes a fuselage 114, two wings 112, a tail 110, and a propulsion system 108 implemented as a tilt-rotor assembly 116 located in a cabin 118. The aircraft 100 includes one or more power sources implemented as a cabin battery pack 104, a wing battery pack 106, and a fuel cell 122 in Figure 1 . In the illustrated example, the cabin battery pack 104 is located in an inner cabin 102, but it should of course be understood that the cabin battery pack 104 can be located in other cabins 118 that form part of the aircraft 100. The battery packs form part of the battery system 200 described with reference to Figure 2 , and the fuel cell 122 forms part of the fuel cell system 300 described with reference to Figure 3 . The cabin battery pack 104, the wing battery pack 106, the fuel cell 122, and the propulsion system 108 are interconnected and operate as discussed below with reference to Figure 5 , Figure 7 and / or Figure 7 . The aircraft 100 will generally include associated equipment such as an electrical infrastructure, control surfaces, a cooling system, landing gear, and the like.

[0035] The wings 112 are used to generate lift to support the aircraft 100 during forward flight. The wings 112 can additionally or alternatively be used to structurally support the battery pack 202, the battery module 204, and / or the propulsion system 108 under the influence of various structural stresses (e.g., aerodynamic, gravitational, propulsive, external point loads, distributed loads, and / or fuselage forces, etc.). The wings 112 can have any suitable geometry and / or arrangement on the aircraft.

[0036] Figure 2 is for use in accordance with some examples Figure 1Schematic diagram of the aircraft battery system 200 in the aircraft 100. As shown, the battery system 200 includes one or more battery packs 202. Each battery pack 202 may include one or more battery modules 204, and the battery module may in turn include a plurality of cells 206.

[0037] Typically associated with the battery pack 202 are one or more electric propulsion systems 108, a battery mate 208 for connecting it to other components in the battery system 200, a burst diaphragm 210 as part of a venting system, a fluid circulation system 212 for cooling, and power electronics 214 that are used to regulate the delivery of power (from the battery during operation and into the battery during charging) and provide integration of the battery pack 202 with the electronic infrastructure of the battery system 200. As Figure 1 shown, the propulsion system 108 may include a plurality of rotor assemblies.

[0038] The electronic infrastructure and the power electronics 214 may additionally or alternatively be used to integrate the battery pack 202 into the energy system of the aircraft. The electronic infrastructure may include a battery management system (BMS), power electronics (HV architecture, power components, etc.), LV architecture (e.g., vehicle wire harness, data connections, etc.) and / or any other suitable components. The electronic infrastructure may include inter-module electrical connections that can transfer power and / or data between the battery packs and / or modules. The inter-module may include bulkhead connections, busbars, wire harnesses and / or any other suitable components.

[0039] The battery pack 202 is used to store electrochemical energy in a rechargeable manner for supply to the propulsion system 108. The battery pack 202 may be arranged and / or distributed around the aircraft in any suitable manner. The battery pack may be arranged inside the wing (e.g., inside the wing cavity), inside the cabin and / or any other suitable location on the aircraft. In a specific example, the system includes a first battery pack in the inner part of the left wing and a second battery pack in the inner part of the right wing. In a second specific example, the system includes a first battery pack in the inner cabin of the left wing and a second battery pack in the inner cabin of the right wing. The battery pack 202 may include a plurality of battery modules 204.

[0040] The battery system 200 includes a cooling system (e.g., the fluid circulation system 212) that is used to circulate a working fluid within the battery pack 202 to remove the heat generated by the battery pack 202 during operation or charging. The battery cells 206, battery modules 204 and / or battery packs 202 may be fluid-connected in series and / or in parallel in any suitable manner by the cooling system.

[0041] Figure 3 is a schematic diagram of an aircraft fuel cell system 300 according to some examples. As shown, the fuel cell system 300 includes one or more fuel cells 314. Each fuel cell 314 may include one or more fuel cell stacks 306.

[0042] Typically associated with the fuel cell 314 are a hydrogen source such as a compressed gaseous or liquid hydrogen tank 402, a recirculation system 304 for supplying hydrogen to and returning hydrogen to the fuel cell 314, a coolant fluid circulation system 308 for transferring heat, power electronics 310 for regulating the power delivery from the fuel cell 314 during operation and providing integration of the fuel cell 314 with the electronic infrastructure of the aircraft 100, and a compressor / cathode air system 312 for supplying compressed air to the fuel cell 314.

[0043] The electronic infrastructure may include an energy supply management system 302 for monitoring and controlling the operation of the fuel cell 314.

[0044] The fuel cell 314 is used to convert chemical energy into electrical energy for supplying to the propulsion system 108 and charging the battery pack 202. The fuel cell 314 may be arranged and / or distributed around the aircraft in any suitable manner. The fuel cell stack may be arranged inside the wing (e.g., inside the wing cavity), inside the cabin, and / or at any other suitable location on the aircraft.

[0045] The fuel cell system 300 may optionally include a heat transfer system (e.g., the fluid circulation system 308), and / or the heat transfer system is used to transfer heat from or to various components of the aircraft 100, for example, by circulating a working fluid inside the fuel cell 314 to remove heat generated during operation, providing heat for the evaporation of liquid hydrogen from the liquid hydrogen tank 402, or removing heat from other heat-generating components inside the aircraft 100.

[0046] Figure 4 is a schematic diagram showing a hydrogen fuel cell system 400 according to some examples. The fuel cell system 400 includes a liquid hydrogen tank 402, a heat exchanger 408, a compressor 404, and a fuel cell 406.

[0047] The liquid hydrogen tank 402, as the name implies, stores liquid hydrogen for the fuel cell 406. The liquid hydrogen tank 402 is connected to the heat exchanger 408 and supplies liquid hydrogen to the heat exchanger 408, which adds heat to the hydrogen before supplying the hydrogen to the fuel cell 406.

[0048] The heat exchanger 408 provides cooling via a coolant loop 416 to other heat generating systems such as the fuel cell 406 or to the compressor 404 that compresses oxygen-containing air used by the fuel cell 406. The coolant loop 416 includes a coolant liquid that can circulate to and from a heat source (not shown) to cool the heat source. In some examples, cold hydrogen gas leaving the liquid hydrogen tank 402 can more directly cool the heat source, such as by locating the heat exchanger 408 at or near the heat source (such as the compressor 404).

[0049] The compressor 404 compresses ambient air 418 and supplies it to the fuel cell at the pressure required by the fuel cell 406. Compressing the ambient air 418 increases its temperature. Thus, coolant from the coolant loop 416 can be used to pre-cool the ambient air 418 at the inlet of the compressor 404 or to cool the compressor 404 itself. Supplying cooler air to the compressor 404 reduces its power consumption. The air leaving the compressor 404 can be cooled or further cooled by an intercooler 420 before being supplied to the fuel cell 406.

[0050] As is known in the art, the warmer hydrogen gas leaving the heat exchanger 408 is received by the fuel cell and, together with the compressed air received from the compressor 404, generates electrical power 410, heat 412, and water vapor exhaust 414. The heat 412 generated by the operation of the fuel cell 406 is removed by a coolant flowing in the heat exchanger 422 as part of a warming loop 424.

[0051] In some examples, in addition to or instead of cooling the ambient air 418 or the compressor 404, the coolant loop 416 is also used to cool the fuel cell 406. Other methods can be used to cool the fuel cell 406 or the air supplied to it.

[0052] Figure 5 An aircraft 500 is shown in accordance with at least one example of the present disclosure. The aircraft 500 can include a fuselage 501, wings 502a and 502b, horizontal stabilizers 503a and 503b, nacelles 504a, 504b, 504c, 504d, 504e, and 504f, and electrical distribution lines 505a, 505b, 505c, 505d.

[0053] As disclosed herein, the aircraft 500 can be powered by batteries 506a, 506b, 506c, 506d and fuel cells 507a and 507b. The batteries 506a to 506d and the fuel cells 507a, 507b can be connected to first electrical devices 508a, 508b, 508c, 508d, 508e and 508f and second electrical devices 509a, 509b, 509c, 509d, 509f and 509e. Non-limiting examples of the first electrical devices 508a to 508f and the second electrical devices 509a to 509f include inverters, motors, coil sets of motors, DC / DC converters, DC / AC inverters, and any combination thereof. For example, one or more of the first electrical devices 508a to 508f can be an inverter that converts direct current (DC) power to alternating current (AC) power to power one or more motors.

[0054] One or more of the first electrical devices 508a to 508f can also be a DC / DC converter that converts a first DC voltage (e.g., a voltage generated by a fuel cell) to a second DC / DC voltage (e.g., a voltage required to drive a motor). The motor can in turn cause one or more propellers and / or rotors of the aircraft to rotate, thereby generating thrust. Still consistent with the examples presented in this disclosure, the batteries 506a to 506d and the fuel cells 507a and 507b can supply power directly to the motor and / or other electrical components without the use of an inverter.

[0055] As disclosed herein, the combination of the batteries 506a to 506d and the fuel cells 507a and 507b provides redundancy. In some examples, the first battery 506a, the third battery 506c, and the first fuel cell 507a can supply power to the first electrical devices 508a to 508e. The second battery 506b, the fourth battery 506d, and the second fuel cell 507b can supply power to the second electrical devices 509a to 509f. In this example, the first electrical devices 508a to 508e and the second electrical devices 509a to 509f are inverters that deliver power to the motor. Thus, the first battery 506a, the third battery 506c, and the first fuel cell 507a form a first distribution system, and the second battery 506b, the fourth battery 506d, and the second fuel cell 507b form a second distribution system. Thus, the second distribution system is a redundant distribution system, and the first distribution system or the second distribution system can power the aircraft in the event of a failure of the other distribution system.

[0056] In some examples, batteries 506a - 506d deliver battery voltage to both the first electrical devices 508a - 508e and the second electrical devices 509a - 509f. The battery voltage from each of batteries 506a - 506d can be the same or different. For example, each of batteries 506a - 506d can deliver a constant 48V. Still consistent with the examples disclosed herein, the first battery 506a and the third battery 506c can deliver 24V, while the second battery 506b and the fourth battery 506d deliver 26V.

[0057] In some examples, fuel cells 507a, 507b deliver a charging voltage to batteries 506a - 506d. For example, during operation, batteries 506a - 506d can provide a voltage, such as 48V, to the first electrical devices 508a - 508e and the second electrical devices 509a - 509f, which can be motors or inverters for motors, depending on the implementation. To keep batteries 506a - 506d charged, fuel cells 507a, 507b can deliver a charging voltage to batteries 506a - 506d, which can be 60V or some other voltage.

[0058] Motors and other electrical devices may require a constant voltage but have varying current consumption. Batteries 506a - 506d can provide a constant voltage while also being able to adequately increase or decrease current or power output as needed based on the load of the electrical devices. In some examples, when batteries 506a - 506d are depleted during use, fuel cells 507a, 507b recharge batteries 506a - 506d.

[0059] Each motor in the six propulsion systems 108 has two sets of windings, where each motor is powered by two inverters, one inverter for each set of windings. In addition to powering the propulsion systems 108, batteries 506a - 506d and fuel cells 507a, 507b also power a rotor deployment mechanism (a nacelle tilt actuator) that positions the rotor 120 during various flight modes (vertical takeoff and landing configuration, forward flight configuration, and transitions therebetween).

[0060] Batteries 506a to 506d and fuel cells 507a, 507b also supply power to the blade pitch motors and position encoders of the rotor 120 (which has variable pitch), to the control surface actuators for positioning various control surfaces on the aircraft 100, and to a set of avionics. The blade pitch motors and the control surface actuators can receive power through one of the DC / DC converters 606a to 606d and appropriately step down or step up the voltage from the battery or fuel cell voltage. A set of avionics is also coupled to the flight computer. When the aircraft 500 is on the ground, the batteries 506a to 506d can also be recharged via an external charger.

[0061] In Figure 5 In the specific example shown, the first fuel cell 507a supplies power to the first battery 506a and the second battery 506b, while the second fuel cell 507b supplies power to the third battery 506c and the fourth battery 506d. The first battery 506a supplies power to the second electrical device 509b, the first electrical device 508d, and the second electrical device 509e via the power distribution line 505a. The second battery 506b supplies power to the first electrical device 508a, the second electrical device 509c, and the second electrical device 509f via the power distribution line 505b. The third battery 506c supplies power to the first electrical device 508b, the second electrical device 509d, and the second electrical device 509e via the power distribution line 505c. The fourth battery 506d supplies power to the first electrical device 508c, the second electrical device 509a, and the first electrical device 508f via the power distribution line 505d.

[0062] Figure 6 A system 600 for distributing electrical energy according to at least one example of the present disclosure is shown. The system 600 can include power distribution lines 601a, 601b, 601c, 601d, batteries 602a, 602b, 602c, and 602d, and fuel cells 603a and 603b. In some examples, the batteries 602a to 602d and the fuel cells 603a, 603b are connected to the first electrical devices 604a, 604b, 604c, 604d, 604e, and 604f and the second electrical devices 605a, 605b, 605c, 605d, 605e, and 605f.

[0063] Non-limiting examples of the first electrical devices 604a to 604f and the second electrical devices 605a to 605f may include inverters, converters, motors, coil sets of motors, and any combination thereof. As disclosed herein, an electrical device (such as the first electrical devices 604a to 604f) may be an inverter that converts direct current (DC) power to alternating current (AC) power to power one or more motors that cause a rotor to rotate to generate thrust. Still consistent with the examples presented in this disclosure, the batteries 602a to 602d and the fuel cells 603a, 603b may supply power directly to the motors and / or other electrical components without the use of an inverter. In some examples, the electrical devices are paired (such as the first electrical device 604a with the second electrical device 605a, the first electrical device 604b with the second electrical device 605b, etc.) such that each pair supplies power to a motor in a single propulsion system 108. In some examples, each of the paired electrical devices powers a different coil set in the motor to provide further redundancy in the event of a failure of a coil set in the motor.

[0064] As disclosed herein, during operation, the first electrical devices 604a to 604f and the second electrical devices 605a to 605f may operate at a constant or near-constant power consumption. However, during various stages of operation, the external load placed on the first electrical devices 604a to 604f and the second electrical devices 605a to 605f may change. For example, during the forward flight portion or the hover portion of a flight, the load on the motors driving the rotors may be relatively constant. However, during takeoff or during the transition from a hover state to forward motion, such as during the rotation of the rotors from a vertical position to a horizontal position, or during maneuvering flight, the load applied to the motors may increase rapidly over a short period of time.

[0065] An increase in load over a short period of time may result in an increase in the current consumed. As disclosed herein, fuel cells 603a, 603b may not be able to generate the required power within a short period of time or at the required power level. However, batteries 602a to 602d are capable of providing the required power. Thus, during high-power operation, batteries 602a to 602d can supply power to the motors or the inverters driving the motors (i.e., the first electrical devices 604a to 604f and the second electrical devices 605a to 605f) to supplement or replace the power provided by fuel cells 603a, 603b. To extend operation beyond the initial charge that batteries 602a to 602d may have, fuel cells 603a, 603b can recharge batteries 602a to 602d continuously or intermittently, such as during steady-state operation, such as during level flight, when excess power is available from fuel cells 603a, 603b.

[0066] System 600 may also have built-in redundancy. As Figure 6 shown, each of batteries 602a to 602d supplies power to three separate electrical devices of the first electrical devices 604a to 604f and the second electrical devices 605a to 605f. In other words, each of batteries 602a to 602d supplies power to a subset of the first electrical devices 604a to 604f and the second electrical devices 605a to 605f.

[0067] As disclosed herein, during operation, each of batteries 602a to 602d can provide a first battery voltage to each of a first subset of the first electrical devices 604a to 604f and the second electrical devices 605a to 605f. Each of batteries 602a to 602d can provide a second battery voltage to each of a second subset of the first electrical devices 604a to 604f and / or the second electrical devices 605a to 605f.

[0068] As Figure 6 shown, the first electrical devices 604a to 604f and the second electrical devices 605a to 605f can be inverters for supplying power to the motors of an electric vertical takeoff and landing (eVTOL) aircraft 100. One electrical device in each of the first electrical devices 604a to 604f and the second electrical devices 605a to 605f can be located at the cabin 118 of the eVTOL aircraft 100 to supply power to the propulsion system 108. Thus, the second electrical devices 605a to 605f can be backup devices for the first electrical devices 604a to 604f.

[0069] As Figure 6As shown, each of batteries 602a to 602d supplies power to three electrical devices. Various electrical devices among the first electrical devices 604a to 604f and the second electrical devices 605a to 605f may be arranged to be located in various cabins of an aircraft (such as aircraft 100, 500). Thus, Figure 6 It may represent a six-rotor eVTOL aircraft 100, where batteries 602a and 602b supply power to each of six motors corresponding to six rotors 120, and batteries 602c and 602d also supply power to each of six motors corresponding to six rotors 120. Thus, batteries 602c and 602d and fuel cell 603b may be used as a redundant system for batteries 602a and 602b and fuel cell 603a, and vice versa.

[0070] System 600 may further include DC / DC converters 606a, 606b, 606c, and 606d. In some examples, DC / DC converters 606a to 606d are in electrical communication with batteries 602a to 602d and fuel cells 603a, 603b. In some examples, during operation, DC / DC converters 606a to 606d convert the fuel cell output voltage from fuel cells 603a, 603b into a battery charging voltage. For example, fuel cells 603a, 603b may output approximately 60V, which may be constant or fluctuating. DC / DC converters 606a to 606d convert or otherwise regulate the output from fuel cells 603a, 603b into a constant voltage, called a charging voltage, such as, for example, 48V, so that fuel cells 603a, 603b can supply a constant voltage to batteries 602a to 602d for charging purposes.

[0071] The voltage generated by batteries 602a to 602d may be the same or different for each battery. For example, if each of batteries 602a to 602d is used to power the motors of the corresponding rotors, the output voltage may be the same because each motor may operate at the same voltage. However, if any of the motors operates at a different voltage, or any of batteries 602a to 602d is used to power other components (such as avionics, lighting devices, etc.) that may operate at a voltage different from that of the rotors, the output voltage of the corresponding battery may be different from that of the other batteries. In other words, although Figure 6 An example is shown where batteries 602a to 602d are used to power rotors that may have the same input voltage requirements, but any one or combination of batteries 602a to 602d may be used to power other electrical devices with different input voltage requirements, and thus, any one or combination of batteries 602a to 602d may provide different input voltages as needed.

[0072] The fuel cells 603a, 603b can also supply the same or different voltages to one or more of the batteries 602a to 602d or the DC / DC converters 606a to 606d. For example, the fuel cell 603a can supply a first voltage to the DC / DC converters 606a and 606b, while the fuel cell 603b can supply a second voltage to the DC / DC converters 606c and 606d. The first voltage and the second voltage, which are referred to as charging voltages, can be the same or different.

[0073] As disclosed herein, the first electrical devices 604a to 604f and the second electrical devices 605a to 605f can be divided into subsets of electrical devices. For example, the electrical devices 605b, 604d, and 605e can form a first subset of electrical devices, and the electrical devices 604b, 605d, and 604e can form a second subset of electrical devices. Thus, in some examples, the first electrical devices 604a and 604b are common functional electrical devices (e.g., inverters that drive a common motor for a rotor).

[0074] In Figure 6 In the specific example shown, the first fuel cell 603a supplies power to the first battery 602a via the DC / DC converter 606a and supplies power to the second battery 602b via the DC / DC converter 606b, while the second fuel cell 603b supplies power to the third battery 602c via the DC / DC converter 606c and supplies power to the fourth battery 602d via the DC / DC converter 606d. The first battery 602a supplies power to the second electrical device 605b, the first electrical device 604d, and the second first electrical device 604e via the power distribution line 601a. The second battery 602b supplies power to the first electrical device 604a, the second electrical device 605c, and the second electrical device 605f via the power distribution line 601b. The third battery 506c supplies power to the first electrical device 604b, the second electrical device 605d, and the second electrical device 605e via the power distribution line 601c. The fourth battery 602d supplies power to the second electrical device 605a, the first electrical device 604c, and the first electrical device 604f via the power distribution line 601d.

[0075] Although not shown for clarity in Figure 6shown, but in some examples, fuel cells 603a and 603b are also coupled to a subset of first electrical devices 604a to 604f and second electrical devices 605a to 605f. In this case, one of each of the two electrical devices for a particular propulsion system 108 is coupled to the first fuel cell 122 or the second fuel cell 122 such that the aircraft 100 can be powered primarily or entirely by fuel cells 603a, 603b during steady-state operation (such as when in a forward flight mode). Additionally, redundancy is provided by coupling the first fuel cell 603a to the electrical devices (first electrical device 604b, second electrical device 605d, second electrical device 605e, second electrical device 605a, first electrical device 604c, and first electrical device 604f) to which the third battery 602c and the fourth battery 602d are coupled and coupling the second fuel cell 603b to the electrical devices (second electrical device 605b, first electrical device 604d, first electrical device 604e, first electrical device 604a, second electrical device 605c, and second electrical device 605f) to which the first battery 602a and the second battery 602b are coupled such that all propulsion systems 108 can be powered by an independent and redundant set of fuel cells and two batteries.

[0076] Although Figure 6 batteries 602a and 602c are shown providing power to a common device (i.e., the same rotor), batteries 602a and 602c can provide power to different components. For example, battery 602a can power electrical devices 605b, 604c, and 605e, while battery 602b can power electrical devices 604a, 605c, and 605f. Thus, batteries 602a to 602d and fuel cells 603a, 603b can provide cross redundancy to first electrical devices 604a to 604f and second electrical devices 605a to 605f.

[0077] Figure 7 A system 700 for distributing electrical energy according to some examples is shown. System 700 can include distribution lines 701a, 701b, 701c, and 701d, batteries 702a and 702b, and fuel cells 703a and 703b. Batteries 702a, 702b and fuel cells 703a, 703b can be connected to first electrical devices 704a, 704b, 704c, 704d, 704e, and 704f and second electrical devices 705a, 705b, 705c, 705d, 705e, and 705f.

[0078] Non-limiting examples of the first electrical devices 704a to 704e and the second electrical devices 705a to 705e include inverters, converters, electric motors, and any combination thereof. As disclosed herein, an electric device (such as the first electrical devices 704a to 704e) can be an inverter that converts direct current (DC) power into alternating current (AC) power to supply one or more electric motors that rotate rotors to generate thrust. Still consistent with the examples presented in this disclosure, the batteries 702a, 702b and the fuel cells 703a, 703b can supply power directly to the motors and / or other electrical components without the use of an inverter.

[0079] As Figure 7 shown, the fuel cells 703a, 703b supply power directly to the first electrical devices 704a to 704e and the second electrical devices 705a to 705e. In this example, the first electrical devices 704a to 704e and the second electrical devices 705a to 705e or a subset thereof can be operated solely by the power supplied by the fuel cells 703a, 703b.

[0080] Each of the first electrical devices 704a to 704e and the second electrical devices 705a to 705e is located at a corresponding position representing the position of the rotors of the eVTOL aircraft 100. As Figure 7 shown, at each position, each of the first electrical devices 704a to 704e is powered by one of the batteries 702a, 702b, and each of the second electrical devices 705a to 705e is powered by the fuel cell 703a, the fuel cell 703b. During steady-state operation, when power consumption can be uniform or otherwise constant, the fuel cells 703a, 703b can supply power to the rotors while allowing the batteries 702a, 702b to remain charged. During transient operation, such as during the transition from hovering to cruise flight, when current consumption may suddenly increase significantly, the batteries 702a, 702b can supply the required power to the various rotors because the batteries 702a, 702b can easily supply the increased power in a responsive manner that the fuel cells may not be able to do. Additionally, by using the batteries to supply or supplement power to peak levels, the fuel cell system can have a lower peak capacity, making it lighter and smaller.

[0081] The fuel cells 703a, 703b can also supply power to the batteries 702a, 702b via the DC / DC converters 706a and 706b. Thus, as disclosed herein, the fuel cells 703a, 703b can recharge the batteries 702a, 702b during steady-state operation. Therefore, during transient operation, when an increase in power may be required, the batteries 702a, 702b can discharge to provide additional power.

[0082] InFigure 7 In the specific example shown, the first fuel cell 703a supplies power to the first battery 702a via the DC / DC converter 706a, and supplies power to the first electrical device 704a, the second electrical device 705c, and the second electrical device 705f via the power distribution line 701c. The second fuel cell 703b supplies power to the second battery 702b via the DC / DC converter 706b, and supplies power to the first electrical device 704b, the second electrical device 705d, and the first electrical device 704e via the power distribution line 701d. The first battery 702a supplies power to the second electrical device 705b, the first electrical device 704d, and the second electrical device 705e via the power distribution line 701a. The second battery 702b supplies power to the second electrical device 705a, the first electrical device 704c, and the first electrical device 704f via the power distribution line 701b.

[0083] As disclosed herein, the battery 702a, the fuel cell 703a, and a subset of the first electrical devices 704a to 704e and the second electrical devices 705a to 705e are a first power distribution system, and the battery 702b, the fuel cell 703b, and another subset of the first electrical devices 704a to 704e and the second electrical devices 705a to 705e form a second or redundant power distribution system. As disclosed herein, the batteries 702a, 702b and the fuel cells 703a, 703b can supply the same or different voltages to the first electrical devices 704a to 704e and the second electrical devices 705a to 705e.

[0084] Figure 8A is a perspective view of an aircraft 100 in a vertical thrust configuration according to some examples. The aircraft 100 has a fixed wing 112, which may be a forward-swept wing, and has a propulsion system 108 of the same or different types, which is adapted for vertical takeoff and landing as well as forward flight. As Figure 8A shown in A, in the vertical takeoff configuration, the propulsion system 108 is positioned or configured for vertical thrust. The propulsion system 108 along the wing includes an electric propulsion system 108 and a rotor 120. The electric propulsion system 108 and the rotor 120 are adapted to be hinged from the forward flight configuration to the vertical flight configuration using a deployment mechanism, which may reside in the nacelle 118 and deploy the motor and the rotor 120 when all or most of the nacelle remains attached to the wing in place. In some aspects, the propeller blades can be retracted and nested into the nacelle body. The motor-driven propulsion system 108 at the wing tip can be deployed from the forward flight configuration to the vertical takeoff and landing configuration along a pivot axis, where the nacelle 118, the electric motor, and the rotor 120 are deployed in cooperation. Although one mid-span propulsion system and one wing tip propulsion system are shown, in some aspects, there may be more mid-span propulsion components.

[0085] The aircraft fuselage 114 extends rearwardly and is attached to the tail wing 110. The tail wing 110 has a rear propulsion system 108 attached thereto. The motor-driven propulsion system 108 at the tip of the tail wing 110 is also deployed from a forward flight configuration to a vertical takeoff and landing configuration along a pivot axis, in which the cabin and the electric motor and propeller are deployed in cooperation.

[0086] Figure 8B is a perspective view of an aircraft 100 in a horizontal thrust configuration according to some examples. In this forward flight configuration, the propulsion system 108 is positioned or configured to provide forward thrust during horizontal flight.

[0087] Figure 9A 、 Figure 9B and Figure 9C illustrate the tilt of the propulsion system 108 and associated components (such as the propeller 902 and the cabin 904) according to some examples. The aircraft is preferably an eVTOL aircraft 100 as shown (e.g., a multimode aircraft), but may additionally or alternatively include any suitable aircraft. The aircraft 100 is preferably a tiltrotor aircraft having a plurality of aircraft propulsion systems that can be operated between a forward arrangement ( Figure 9A and Figure 10A ) and a hover or vertical flight arrangement ( Figure 9C and Figure 10C ). However, the aircraft may alternatively be a fixed-wing aircraft having one or more rotor assemblies or propulsion systems, a helicopter having one or more rotor assemblies (e.g., where at least one rotor assembly or aircraft propulsion system is substantially axially oriented to provide horizontal thrust), a tilt-wing aircraft, a wingless aircraft (e.g., a helicopter, a multirotor aircraft, a quadcopter), and / or any other suitable rotorcraft or vehicle propelled by a propeller or rotor.

[0088] As Figures 9A to 9C shown, in one example, the cabin 904 including the aircraft propulsion system 108 (including an electric motor, two power inverters, and a radiator) and the propeller 902 having a blade pitch mechanism 908 is tilted relative to the remainder of the aircraft 100 by a tilt mechanism 906 positioned toward the rear of the cabin 904.

[0089] As described below, when integrated into a propulsion tilt mechanism of an aircraft configurable between a forward configuration and a hover configuration, the cooling subsystem can advantageously utilize the increased available airflow in the hover configuration.

[0090] Figure 10A 、 Figure 10B and Figure 10CIllustrates the tilt of the propulsion system 108 and associated components (such as the propeller 902) relative to the nacelle 1004 according to some examples. As can be seen in Figure 10B and Figure 10C In this example, the aircraft propulsion system 108 (including an electric motor, two inverters, and a radiator) and the propeller 1002 having a blade pitch mechanism 1008 are tilted relative to the nacelle 1004 by a tilt mechanism 1006 positioned towards the front of the nacelle 1004.

[0091] Figure 11 Is a flowchart 1100 showing a method of supplying power to the propulsion system 108 of the aircraft 100 according to some examples. For purposes of explanation, the operations of the flowchart 1100 are described herein as occurring serially or linearly. However, multiple operations of the flowchart 1100 can occur in parallel. Additionally, the operations of the flowchart 1100 need not be performed in the order shown and / or one or more blocks of the flowchart 1100 need not be performed and / or can be replaced by other operations. The operations of the flowchart 1100 can be performed individually or in combination by the power electronics 214, the power electronics 310, the energy supply management system 302, or another computing device located in the aircraft 100.

[0092] The flowchart 1100 begins at operation 1102, where the aircraft 100 operates in a fuel cell mode, in which the aircraft, particularly its propulsion system 108, is powered only by the fuel cell 122. For example, this could be a situation where the aircraft 100 is flying forward at a consistent cruise speed and altitude. Alternatively, the aircraft could be on the ground, the rotors stationary, and the avionics and other systems powered only by the fuel cell.

[0093] At operation 1104, a control input or command is received from the pilot or autonomous system operating the aircraft 100. At operation 1106, it is determined whether the power required to execute the control input or command exceeds or will exceed a predetermined threshold, or whether the rate of increase of the power will exceed a predetermined threshold. This can be determined dynamically by monitoring the power consumed by the propulsion system and / or the rate of change of the power consumed, the voltage and / or frequency of the power signal, or can be determined predictively or contextually, for example, based on the position of the aircraft, whether the nacelle 118 is in a vertical or horizontal thrust generation mode, based on the flight plan of the aircraft, or based on the nature of the command or instruction received.

[0094] If it is determined in operation 1106 that the required power does not or will not exceed a threshold (e.g., if the aircraft 100 is in forward flight mode and the command or instruction involves a change in direction or a descent to be made), or if it is determined by monitoring dynamic power, the rate of change of power consumed, current, frequency, etc. that the power does not exceed the threshold, then the flowchart 1100 returns to operation 1102 and the aircraft 100 continues to operate in fuel cell mode.

[0095] If it is determined in operation 1106 that the required power exceeds or will exceed the threshold (e.g., if the aircraft 100 is on the ground and the command or instruction involves powering the rotors to take off, or if the aircraft is in forward flight and the command or instruction will enter hover mode, or based on parameters related to power consumption), then in operation 1108, the aircraft operates in battery mode. In battery mode, at least some of the power supplied to the propulsion system is from batteries (such as the cabin battery pack 104 and the wing battery pack 106 or the batteries described in reference Figure 5 , Figure 6 and Figure 7 ).

[0096] In battery mode, the battery supplements the power supplied to the propulsion system 108 such that the power demand is met. This allows the fuel cell 122 to continue operating in a more stable manner without the need for rapid adjustment of the fuel cell's power output. In some examples, the battery may supply all of the power to one or more or all of the propulsion systems 108. In operation 1110, a further control input is received.

[0097] In operation 1112, it is determined whether the power required by the propulsion system 108 continues to exceed a predetermined power threshold. If it is determined in operation 1112 that the required power no longer exceeds the threshold (e.g., if the aircraft 100 has transitioned from vertical thrust mode to forward flight mode, resulting in a decrease in power consumed to below the predetermined threshold), then the flowchart 1100 returns to operation 1102 and the aircraft 100 resumes operation in fuel cell mode.

[0098] If it is determined in operation 1106 that the power required by the propulsion system 108 continues to exceed the predetermined threshold, then in operation 1108 the aircraft continues to operate in battery mode. In battery mode, at least some of the power supplied to the propulsion system is from batteries (such as the cabin battery pack 104 and the wing battery pack 106 or the batteries described in reference Figure 5 , Figure 6 and Figure 7 ).

[0099] The flowchart 1100 then continues from operation 1102 or operation 1108 as appropriate.

[0100] When the aircraft 100 is operating in fuel cell mode, it is also determined in operation 1114 whether the fuel cell has additional capacity. If the fuel cell does not have additional capacity, then in operation 1102, the aircraft 100 continues to operate in fuel cell mode. If it is determined in operation 1114 that the fuel cell has additional capacity, then it is determined in operation 1116 whether the battery needs to be charged. This determination depends primarily on the state of charge, but can also be based on other factors such as the flight plan and expected demand from the battery, the charging history of individual batteries or battery packs, the available hydrogen in the liquid hydrogen tank 402, etc. If the battery needs to be charged or if charging is appropriate, then in operation 1118 the battery is charged and the flowchart returns to operation 1102 and continues from there.

[0101] It will be appreciated that various alternatives can be envisioned. When performing full dynamic monitoring of the power, current, and / or frequency of the power delivered to the propulsion system 108, for example, strictly speaking, it will not be necessary to receive and evaluate control inputs in operations 1104 and 1110, although as described above, this can provide additional context or predictive data.

[0102] Figure 12 A diagrammatic representation of a machine 1200 in the form of a computer system according to an example is shown, within which a set of instructions can be executed to cause the machine to perform any one or more of the methods discussed herein. For example, the power electronics 214, the power electronics 310, and the energy supply management system 302 can be implemented as the machine 1200.

[0103] Specifically, Figure 12A graphical representation of a machine 1200 is shown in the example form of a computer system, and instructions 1208 (e.g., software, program, application, applet, app, or other executable code) for causing the machine 1200 to execute any one or more of the methods discussed herein can be executed within the machine. The instructions 1208 transform the general, unprogrammed machine 1200 into a particular machine 1200 programmed to perform the described and illustrated functions in the described manner. In an alternative example, the machine 1200 operates as a stand-alone device or can be coupled (e.g., networked) to other machines. In a networked deployment, the machine 1200 can operate as a server machine or a client machine in a server-client network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. The machine 1200 can include, but is not limited to, a server computer, a client computer, a personal computer (PC), a tablet computer, a laptop computer, a netbook, a set-top box (STB), a PDA, an entertainment media system, a cellular phone, a smartphone, a mobile device, a wearable device (e.g., a smartwatch), a smart home device (e.g., a smart appliance), other smart devices, a web device, a network router, a network switch, a network bridge, or any machine capable of executing the instructions 1208 sequentially or otherwise, where the instructions 2804 specify actions to be taken by the machine 1200. Further, although only a single machine 1200 is shown, the term "machine" shall also be understood to include a collection of machines 1200 that individually or jointly execute the instructions 1208 to perform any one or more of the methods discussed herein.

[0104] The machine 1200 can include a processor 1202, a memory 1204, and I / O components 1242, which can be configured to communicate with each other, such as via a bus 1244. In an example, the processor 1202 (e.g., a central processing unit (CPU), a reduced instruction set computing (RISC) processor, a complex instruction set computing (CISC) processor, a graphics processing unit (GPU), a digital signal processor (DSP), an ASIC, a radio frequency integrated circuit (RFIC), another processor, or any suitable combination thereof) can include, for example, a processor 1206 and a processor 1210 that can execute the instructions 1208. The term "processor" is intended to include multi-core processors, which can include two or more independent processors (sometimes referred to as "cores") that can execute instructions simultaneously. Although Figure 12 multiple processors 1202 are shown, the machine 1200 can include a single processor with a single core, a single processor with multiple cores (e.g., a multi-core processor), multiple processors with a single core, multiple processors with multiple cores, or any combination thereof.

[0105] Memory 1204 may include main memory 1212, static memory 1214, and storage unit 1216, all of which may be accessed by processor 1202, for example, via bus 1244. Main memory 1204, static memory 1214, and storage unit 1216 store instructions 1208 for implementing any one or more of the methods or functions described herein. During execution of instructions 1208 by machine 1200, the instructions 1208 may also reside completely or partially within main memory 1212, within static memory 1214, within machine-readable medium 1218 within storage unit 1216, within at least one of processors 1202 (e.g., within a cache memory of the processor), or in any suitable combination thereof.

[0106] I / O components 1242 may include various components for receiving input, providing output, generating output, transmitting information, exchanging information, capturing measurements, and the like. The specific I / O components 1242 included in a particular machine will depend on the type of machine. For example, a portable machine such as a mobile phone will likely include a touch input device or other such input mechanism, while a headless server machine will unlikely include such a touch input device. It will be appreciated that I / O components 1242 may include Figure 12 many other components not shown herein. The grouping of I / O components 1242 by function is for simplicity of discussion only and is in no way limiting. In various examples, I / O components 1242 may include output components 1228 and input components 1230. Output components 1228 may include visual components (e.g., a display, such as a plasma display panel (PDP), light emitting diode (LED) display, liquid crystal display (LCD), projector, or cathode ray tube (CRT)), acoustic components (e.g., a speaker), haptic components (e.g., a vibration motor, a resistive mechanism), other signal generators, and the like. Input components 1230 may include alphanumeric input components (e.g., a keyboard, a touch screen configured to receive alphanumeric input, an optical keyboard, or other alphanumeric input components), pointing-based input components (e.g., a mouse, a touchpad, a trackball, a joystick, a motion sensor, or another pointing instrument), touch input components (e.g., a physical button, a touch screen that provides location and / or force of a touch or touch gesture, or other touch input components), audio input components (e.g., a microphone), and the like.

[0107] In additional examples, I / O component 1242 can include biometric component 1232, motion component 1234, environmental component 1236, or location component 1238, as well as a variety of other components. For example, biometric component 1232 can include components for detecting expressions (e.g., hand expressions, facial expressions, voice expressions, body postures, or eye tracking), measuring biometric signals (e.g., blood pressure, heart rate, body temperature, sweating, or brain waves), identifying people (e.g., voice recognition, retina recognition, facial recognition, fingerprint recognition, or electroencephalogram-based recognition), and so on. Motion component 1234 can include acceleration sensor components (e.g., accelerometers), gravity sensor components, rotational sensor components (e.g., gyroscopes), and so on. Environmental component 1236 can, for example, include lighting sensor components (e.g., photometers), temperature sensor components (e.g., one or more thermometers for detecting ambient temperature), humidity sensor components, pressure sensor components (e.g., barometers), acoustic sensor components (e.g., one or more microphones for detecting background noise), proximity sensor components (e.g., infrared sensors for detecting nearby objects), gas sensors (e.g., gas detection sensors for detecting hazardous gas concentrations for safety or measuring pollutants in the atmosphere), or other components that can provide indications, measurements, or signals corresponding to the surrounding physical environment. Location component 1238 can include location sensor components (e.g., GPS receiver components), altitude sensor components (e.g., altimeters or barometers that detect air pressure from which altitude can be derived), orientation sensor components (e.g., magnetometers), and so on.

[0108] Communication can be implemented using a variety of techniques. I / O component 1242 can include communication component 1240, which is operable to couple machine 1200 to network 1220 or device 1222 via couplings 1224 and 1226, respectively. For example, communication component 1240 can include a network interface component or another suitable device for interfacing with network 1220. In additional examples, communication component 1240 can include wired communication components, wireless communication components, cellular communication components, near field communication (NFC) components, components (e.g., low power consumption), components, and other communication components to provide communication via other modalities. Device 1222 can be any other machine or a variety of peripheral devices (e.g., peripheral devices coupled via USB).

[0109] In addition, communication component 1240 may detect an identifier or include components operable to detect an identifier. For example, communication component 1240 may include a radio frequency identification (RFID) tag reader component, an NFC smart tag detection component, an optical reader component (e.g., an optical sensor for detecting one-dimensional barcodes such as Universal Product Code (UPC) barcodes, multi-dimensional barcodes such as Quick Response (QR) codes, Aztec codes, Data Matrix, Dataglyph, MaxiCode, PDF417, Ultra codes, UCC RSS-2D barcodes, and other optical codes), or an acoustic detection component (e.g., a microphone for identifying tagged audio signals). Additionally, various information such as a location via Internet Protocol (IP) geolocation, a location via signal triangulation, a location via detecting an NFC beacon signal that may indicate a particular location, etc., may be derived via communication component 1240.

[0110] Executable instructions and machine storage media

[0111] Various memories (i.e., memory 1204, main memory 1212, static memory 1214, and / or the memory of processor 1202) and / or storage unit 1216 may store one or more sets of instructions and data structures (e.g., software) that implement any one or more of the methods or functions described herein or are utilized by any one or more of the methods or functions described herein. These instructions (e.g., instructions 1208), when executed by processor 1202, cause the various operations to implement the disclosed examples.

[0112] As used herein, the terms "machine storage medium", "device storage medium", and "computer storage medium" have the same meaning and may be used interchangeably in this disclosure. These terms refer to one or more storage devices and / or media that store executable instructions and / or data (e.g., a centralized or distributed database and / or associated caches and servers). Accordingly, these terms should be considered to include, but not be limited to, solid-state memory including memory internal or external to a processor, as well as optical and magnetic media. Specific examples of machine storage medium, computer storage medium, and / or device storage medium include non-volatile memory, which includes, for example, semiconductor memory devices such as erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), FPGA, and flash memory devices; magnetic disks such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. The terms "machine storage medium", "computer storage medium", and "device storage medium" specifically exclude carrier waves, modulated data signals, and other such media (at least some of which are included in the term "signal medium" discussed below).

[0113] Transmission medium

[0114] In various examples, one or more portions of network 1220 may be an ad hoc network, an intranet, an extranet, a VPN, a LAN, a WLAN, a WAN, a WWAN, a MAN, the Internet, a portion of the Internet, a portion of the PSTN, a plain old telephone service (POTS) network, a cellular telephone network, a wireless network, a network, another type of network, or a combination of two or more such networks. For example, network 1220 or a portion of network 1220 may include a wireless or cellular network, and coupling 1224 may be a code division multiple access (CDMA) connection, a global system for mobile communications (GSM) connection, or another type of cellular or wireless coupling. In this example, coupling 1224 may implement any of a variety of types of data transmission technologies, such as single-carrier radio transmission technology (1xRTT), evolution data optimized (EVDO) technology, general packet radio service (GPRS) technology, enhanced data rate GSM evolution (EDGE) technology, including third-generation partnership project (3GPP) standards including 3G, fourth-generation wireless (4G) networks, universal mobile telecommunications system (UMTS), high-speed packet access (HSPA), worldwide interoperability for microwave access (WiMAX), long-term evolution (LTE), other technologies defined by various standards-setting organizations, other long-range protocols, or other data transmission technologies.

[0115] Instruction 1208 can be transmitted or received over network 1220 using a transmission medium via a network interface device (e.g., a network interface component included in communication component 1240) and utilizing any of a variety of well-known transmission protocols such as the Hypertext Transfer Protocol (HTTP). Similarly, instruction 1208 can be transmitted or received to device 1222 using a transmission medium via coupling 1226 (e.g., a peer-to-peer coupling). The terms "transmission medium" and "signal medium" mean the same and may be used interchangeably in this disclosure. The terms "transmission medium" and "signal medium" should be understood to include any non-transitory medium that is capable of storing, encoding, or carrying instruction 1208 for execution by machine 1200 and includes digital or analog communication signals or other non-transitory media that facilitate communication of such software. Thus, the terms "transmission medium" and "signal medium" should be understood to include any form of modulated data signal, carrier wave, etc. The term "modulated data signal" means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal.

[0116] Computer-readable medium

[0117] The terms "machine-readable medium", "computer-readable medium", and "device-readable medium" mean the same and may be used interchangeably in this disclosure. These terms are defined to include machine storage media and transmission media. Thus, these terms include both storage devices / media and carrier waves / modulated data signals.

[0118] Examples of systems and / or methods can include each combination and permutation of various system components and various method processes, where one or more instances of the methods and / or processes described herein can be executed asynchronously (e.g., sequentially), simultaneously (e.g., in parallel), or in any other suitable order by and / or using one or more instances of the systems, elements, and / or entities described herein.

[0119] When referring to thrust generating elements, the term "rotor" as used herein can refer to a rotor, a propeller, and / or any other suitable rotary aerodynamic actuator. While a rotor can refer to a rotary aerodynamic actuator that utilizes a hinged or semi-rigid hub (e.g., where the connection of the blade to the hub can be hinged, flexible, rigid, and / or otherwise connected), and a propeller can refer to a rotary aerodynamic actuator that utilizes a rigid hub (e.g., where the connection of the blade to the hub can be hinged, flexible, rigid, and / or otherwise connected), no such distinction is made explicitly or implied when used herein, and the use of "rotor" can refer to configurations of hinged or rigid blades and any other suitable configuration, and / or any other suitable configuration in which the blade is connected to a central member or hub. Similarly, the use of "propeller" can refer to either configuration of hinged or rigid blades and any other suitable configuration, and / or any other suitable configuration in which the blade is connected to a central member or hub. Thus, a tiltrotor aircraft can be referred to as a tilt-propeller aircraft, a tilt-prop aircraft, and / or otherwise appropriately referred to or described.

[0120] The term "board" as used herein, with reference to a control board, an inverter board, or others, preferably refers to a circuit board. More preferably, "board" refers to a printed circuit board (PCB) and / or the electronic components assembled thereon, which can jointly form a printed circuit board assembly (PCBA). In a first example, the control board is a PCBA. In a second example, each inverter board is a PCBA. However, "board" can additionally or alternatively refer to a single-sided PCB, a double-sided PCB, a multi-layer PCB, a rigid PCB, a flexible PCB, and / or can have any other suitable meaning.

[0121] The aircraft can include any suitable form of electrical storage or electrical storage unit (battery, flywheel, supercapacitor, cell, fuel tank, etc.) for powering actuators (e.g., rotor / propeller, tilt mechanism, blade pitch mechanism, cooling system, etc.). The preferred power / fuel source is a battery; however, the system can reasonably be used with any suitable power / fuel source. The aircraft can include auxiliary and / or redundant power sources (e.g., a backup battery, multiple batteries) or not include a redundant power source. The aircraft can employ batteries having any suitable battery chemistry (e.g., lithium-ion, nickel cadmium, etc.) in any suitable electrical architecture or configuration (e.g., multiple battery packs, bricks, modules, cells, etc.; any combination of series and / or parallel architectures).

[0122] In a specific example, a system integrated into an electric tiltrotor aircraft includes a plurality of tiltrotor assemblies (e.g., six tiltrotor assemblies). The electric tiltrotor aircraft can operate as a fixed-wing aircraft, a rotary-wing aircraft, and any transitional configuration (liminal configuration) between the fixed-wing state and the rotary-wing state (e.g., where one or more of the plurality of tiltrotor assemblies are oriented in a partially rotated state). In this example, the control system of the electric tiltrotor aircraft can be used to command and control the plurality of tiltrotor assemblies within and / or between the fixed-wing arrangement and the rotary-wing arrangement.

[0123] As used herein, the term "substantially" can mean: precisely, approximately, within a predetermined threshold or tolerance, and / or have any other suitable meaning.

[0124] Alternative examples implement the above methods and / or processing modules in a non-transitory computer-readable medium storing computer-readable instructions. The instructions can be executed by computer-executable components integrated with the computer-readable medium and / or the processing system. The computer-readable medium can include any suitable computer-readable medium, such as RAM, ROM, flash memory, EEPROM, optical devices (CD or DVD), hard disk drives, floppy disk drives, non-transitory computer-readable media, or any suitable device. The computer-executable components can include a computing system and / or a processing system (e.g., including one or more collocated or distributed, remote or local processors) connected to a non-transitory computer-readable medium such as a CPU, GPU, TPU, microprocessor, or ASIC, but the instructions can alternatively or additionally be executed by any suitable dedicated hardware device.

[0125] Examples of the system and / or method can include every combination and permutation of various system components and various method processes, where one or more instances of the methods and / or processes described herein can be executed asynchronously (e.g., sequentially), simultaneously (e.g., in parallel), or in any other suitable order by and / or using one or more instances of the systems, elements, and / or entities described herein.

[0126] As those skilled in the art will recognize from the foregoing detailed description, and from the drawings and claims, modifications and variations can be made to the examples of the present invention without departing from the scope of the invention as defined in the appended claims.

[0127] Examples of systems and / or methods can include every combination and permutation of various system components and various method procedures, where one or more instances of the methods and / or procedures described herein can be performed asynchronously (e.g., sequentially), simultaneously (e.g., in parallel), or in any other suitable order by and / or using one or more instances of the systems, elements, and / or entities described herein.

[0128] As will be recognized by those skilled in the art from the foregoing detailed description and from the drawings and claims, modifications and variations can be made to the examples of the invention disclosed herein without departing from the scope of the invention as defined in the appended claims.

[0129] The following non - limiting examples detail certain aspects of the subject matter to address challenges and provide the benefits discussed herein, etc.

[0130] Example 1 is a system for distributing electrical energy, the system including: a first set of electrical devices; a second set of electrical devices; a first battery system coupled to one or more of the first set of electrical devices; a first fuel cell coupled to one or more of the first set of electrical devices; a second battery system coupled to one or more of the second set of electrical devices; and a second fuel cell coupled to one or more of the second set of electrical devices.

[0131] In Example 2, the subject matter of Example 1 includes, wherein the first fuel cell is coupled to the first battery system to charge the first battery system.

[0132] In Example 3, the subject matter of Examples 1 - 2 includes, wherein the first fuel cell is coupled to the second battery system to charge the second battery system.

[0133] In Example 4, the subject matter of Examples 1 - 3 includes a set of propulsion systems, each of which has electrical devices from the first set of electrical devices coupled thereto and electrical devices from the second set of electrical devices coupled thereto.

[0134] In Example 5, the subject matter of Example 4 includes, wherein one or more of the first set of electrical devices coupled to the first fuel cell and one or more of the second set of electrical devices coupled to the first fuel cell cumulatively supply power to all the propulsion systems such that all the propulsion systems can be powered by the first fuel cell and the second fuel cell together.

[0135] In Example 6, the subject matter of Examples 4-5 includes that one or more of the first set of electric devices coupled to the first battery system and one or more of the first set of electric devices coupled to the second battery system cumulatively supply power to all propulsion systems, such that all propulsion systems can be powered by the first battery system and the second battery system together.

[0136] In Example 7, the subject matter of Examples 5-6 includes that one or more of the first set of electric devices coupled to the first battery system and one or more of the first set of electric devices coupled to the second battery system cumulatively supply power to all propulsion systems, such that all propulsion systems can be powered by the first battery system and the second battery system together.

[0137] In Example 8, the subject matter of Examples 4-7 includes that during operation, the first fuel cell and the second fuel cell power the set of propulsion systems during steady-state operation.

[0138] In Example 9, the subject matter of Example 8 includes that during operation, the first fuel cell and the second fuel cell recharge the first battery system and the second battery system during steady-state operation.

[0139] In Example 10, the subject matter of Examples 6-9 includes that during operation, the first battery system and the second battery system supply power to the set of propulsion systems during high-power operation of the propulsion systems.

[0140] In Example 11, the subject matter of Example 10 includes that during operation, the first fuel cell and the second fuel cell also supply power to the set of propulsion systems during high-power operation of the propulsion systems.

[0141] In Example 12, the subject matter of Examples 8-11 includes that during operation, the first battery system and the second battery system supply power to the set of propulsion systems during high-power operation of the propulsion systems.

[0142] In Example 13, the subject matter of Example 12 includes that during operation, the first fuel cell and the second fuel cell also supply power to the set of propulsion systems during high-power operation of the propulsion systems.

[0143] In Example 14, the subject matter of Examples 9-13 includes that the steady-state operation is a horizontal flight mode in an aircraft.

[0144] In Example 15, the subject matter of Examples 10-14 includes that the high-power operation is a vertical flight mode in an aircraft.

[0145] In Example 16, the subject matter of Examples 10 - 15 includes that the first battery system and the second battery system each include a plurality of batteries, and each of the plurality of batteries in each of the first battery system and the second battery system is coupled to a different electrical device among the first set of electrical devices and the second set of electrical devices.

[0146] Example 17 is a method of operating a system for distributing electrical energy, the system including a first set of electrical devices; a second set of electrical devices; a first battery system coupled to one or more of the first set of electrical devices; a first fuel cell coupled to one or more of the first set of electrical devices; a second battery system coupled to one or more of the second set of electrical devices; a second fuel cell coupled to one or more of the second set of electrical devices; and a set of propulsion systems, each of which has an electrical device from the first set of electrical devices coupled thereto and an electrical device from the second set of electrical devices coupled thereto. The method includes: powering the set of propulsion systems using the first fuel cell and the second fuel cell during steady - state operation; and at least partially powering the set of propulsion systems using the first battery system and the second battery system during high - power operation.

[0147] In Example 18, the subject matter of Example 17 includes at least partially powering the set of propulsion systems using the first fuel cell and the second fuel cell during high - power operation.

[0148] In Example 19, the subject matter of Examples 17 - 18 includes recharging the first battery system and the second battery system during steady - state operation.

[0149] In Example 20, the subject matter of Examples 17 - 19 includes that the steady - state operation is a horizontal flight mode in an aircraft, and the high - power operation is a vertical flight mode in an aircraft.

[0150] Example 21 is a system for distributing electrical energy, the system including: a first battery and a second battery; a first fuel cell; a first DC / DC converter in electrical communication with the first fuel cell and the first battery; and a second DC / DC converter in electrical communication with the first fuel cell and the second battery; wherein during operation: the first battery provides a first battery voltage to each of one or more electrical devices, the second battery provides a second battery voltage to each of a second subset of the electrical devices, the first DC / DC converter converts a fuel cell voltage from the first fuel cell into a first battery charging voltage for the first battery, and the second DC / DC converter converts the fuel cell voltage from the first fuel cell into a second battery charging voltage for the second battery.

[0151] In Example 22, the subject matter of Example 1 optionally includes a third battery and a fourth battery; a second fuel cell; a third DC / DC converter electrically connected to the second fuel cell and the third battery; and a fourth DC / DC converter electrically connected to the second fuel cell and the fourth battery; wherein during operation, the third battery and the fourth battery, the second fuel cell, and the third DC / DC converter and the fourth DC / DC converter form a redundant system for the first battery and the second battery, the first fuel cell, and the first DC / DC converter and the second DC / DC converter.

[0152] In Example 23, the subject matter of any one or more of Examples 1-2 optionally includes, wherein the first battery voltage is approximately equal to the second battery voltage.

[0153] In Example 24, the subject matter of any one or more of Examples 1-3 optionally includes, wherein the first battery voltage is different from the second battery voltage.

[0154] In Example 25, the subject matter of any one or more of Examples 1-4 optionally includes, wherein the fuel cell voltage is approximately equal to at least one of the first battery voltage and the second battery voltage.

[0155] In Example 26, the subject matter of any one or more of Examples 1-5 optionally includes a first subset and a second subset of electrical devices, wherein the first subset of electrical devices and the second subset of electrical devices include at least one common electrical device.

[0156] In Example 27, the subject matter of any one or more of Examples 1-6 optionally includes a second fuel cell; and a second DC / DC converter electrically connected to the second fuel cell and the first battery and the second battery.

[0157] In Example 28, the subject matter of any one or more of Examples 1-7 optionally includes, wherein at least one of the electrical devices is an inverter.

[0158] In Example 29, the subject matter of any one or more of Examples 1-8 optionally includes, wherein at least one of the electrical devices is an electric motor.

[0159] Example 30 is an aircraft including the system of Example 1.

[0160] Example 31 is a system for distributing electrical energy, the system including: a first battery electrically connected to a first electrical device and a second electrical device; a first fuel cell electrically connected to a third electrical device and a fourth electrical device; and a first DC / DC converter electrically connected to the first fuel cell and the first battery; wherein during operation: the first battery supplies a first battery voltage to each of the first electrical device and the second electrical device, the first fuel cell supplies a first fuel cell voltage to each of the third electrical device and the fourth electrical device, and the first DC / DC converter converts the first fuel cell voltage to a first battery charging voltage.

[0161] In Example 32, the subject matter of Example 11 optionally includes: a second battery electrically connected to a fifth electrical device and a sixth electrical device; a second fuel cell electrically connected to a seventh electrical device and an eighth electrical device; and a second DC / DC converter electrically connected to the second fuel cell and the second battery; wherein during operation, the second battery, the second fuel cell, and the second DC / DC converter form a redundant system for the first battery, the first fuel cell, and the first DC / DC converter.

[0162] In Example 33, the subject matter of any one or more of Examples 11-12 optionally includes, wherein the first battery voltage is approximately equal to the first fuel cell voltage.

[0163] In Example 34, the subject matter of any one or more of Examples 11-13 optionally includes, wherein the first battery voltage is different from the first fuel cell voltage.

[0164] In Example 35, the subject matter of any one or more of Examples 11-14 optionally includes, wherein the fuel cell voltage is different from the first battery charging voltage.

[0165] In Example 36, the subject matter of any one or more of Examples 11-15 optionally includes the first electrical device, the second electrical device, the third electrical device, and the fourth electrical device, wherein the first electrical device and the third electrical device are a first common electrical device, and the second electrical device and the fourth electrical device are a second common electrical device.

[0166] In Example 37, the subject matter of any one or more of Examples 11-16 optionally includes, wherein at least one of the electrical devices is an inverter.

[0167] In Example 38, the subject matter of any one or more of Examples 11-17 optionally includes, wherein at least one of the electrical devices is an electric motor.

[0168] Example 39 is an aircraft including the system of Example 11.

[0169] Example 40 is an aircraft that includes: an electrical power distribution system that includes: a first battery and a second battery; a first fuel cell; a first DC / DC converter electrically connected to the first fuel cell and the first battery; and a second DC / DC converter electrically connected to the first fuel cell and the second battery; wherein during operation: the first battery provides a first battery voltage to each of one or more electrical devices, the second battery provides a second battery voltage to each of a second subset of the electrical devices, the first DC / DC converter converts a fuel cell voltage from the first fuel cell into a first battery charging voltage for the first battery, and the second DC / DC converter converts the fuel cell voltage from the first fuel cell into a second battery charging voltage for the second battery.

[0170] In Example 41, the subject matter of Example 20 optionally includes a third battery and a fourth battery; a second fuel cell; a third DC / DC converter electrically connected to the second fuel cell and the third battery; and a fourth DC / DC converter electrically connected to the second fuel cell and the fourth battery; wherein during operation, the third battery and the fourth battery, the second fuel cell, and the third DC / DC converter and the fourth DC / DC converter form a redundant system for the first battery and the second battery, the first fuel cell, and the first DC / DC converter and the second DC / DC converter.

[0171] In Example 42, the subject matter of any one or more of Examples 20-21 optionally includes, wherein the first battery voltage is approximately equal to the second battery voltage.

[0172] In Example 43, the subject matter of any one or more of Examples 20-22 optionally includes, wherein the first battery voltage is different from the second battery voltage.

[0173] In Example 44, the subject matter of any one or more of Examples 20-23 optionally includes, wherein the fuel cell voltage is approximately equal to at least one of the first battery voltage and the second battery voltage.

[0174] In Example 45, the subject matter of any one or more of Examples 20-24 optionally includes a first subset and a second subset of electrical devices, wherein the first subset of electrical devices and the second subset of electrical devices include at least one common electrical device.

[0175] In Example 46, the subject matter of any one or more of Examples 20-25 optionally includes a second fuel cell; and a second DC / DC converter electrically connected to the second fuel cell and the first battery and the second battery.

[0176] In Example 47, the subject matter of any one or more of Examples 20-26 optionally includes, wherein at least one of the electrical devices is an inverter.

[0177] In Example 48, the subject matter of any one or more of Examples 20 - 27 optionally includes, where at least one of the electrical devices is an electric motor.

[0178] Example 49 is an aircraft that includes: an electrical power distribution system that includes: a first battery electrically connected to a first electrical device and a second electrical device; a first fuel cell electrically connected to a third electrical device and a fourth electrical device; and a first DC / DC converter electrically connected to the first fuel cell and the first battery; where during operation: the first battery supplies a first battery voltage to each of the first electrical device and the second electrical device, the first fuel cell supplies a first fuel cell voltage to each of the third electrical device and the fourth electrical device, and the first DC / DC converter converts the first fuel cell voltage to a first battery charging voltage.

[0179] In Example 50, the subject matter of Example 29 optionally includes: a second battery electrically connected to a fifth electrical device and a sixth electrical device; a second fuel cell electrically connected to a seventh electrical device and an eighth electrical device; and a second DC / DC converter electrically connected to the second fuel cell and the second battery; where during operation, the second battery, the second fuel cell, and the second DC / DC converter form a redundant system for the first battery, the first fuel cell, and the first DC / DC converter.

[0180] In Example 51, the subject matter of any one or more of Examples 29 - 30 optionally includes, where the first battery voltage is approximately equal to the first fuel cell voltage.

[0181] In Example 52, the subject matter of any one or more of Examples 29 - 31 optionally includes, where the first battery voltage is different from the first fuel cell voltage.

[0182] In Example 53, the subject matter of any one or more of Examples 29 - 32 optionally includes, where the fuel cell voltage is different from the first battery charging voltage.

[0183] In Example 54, the subject matter of any one or more of Examples 29 - 33 optionally includes the first electrical device, the second electrical device, the third electrical device, and the fourth electrical device, where the first electrical device and the third electrical device are a first common electrical device, and the second electrical device and the fourth electrical device are a second common electrical device.

[0184] In Example 55, the subject matter of any one or more of Examples 29 - 34 optionally includes, where at least one of the electrical devices is an inverter.

[0185] In Example 56, the subject matter of any one or more of Examples 29-35 optionally includes where at least one of the electrical devices is an electric motor.

[0186] In Example 57, any one or any combination of the devices or methods of Examples 1-36 can optionally be configured such that all of the elements or options described are available for use or selectable therefrom.

[0187] Example 58 is at least one machine-readable medium including instructions that, when executed by a processing circuit, cause the processing circuit to perform operations to implement any one of Examples 1-57. Example 59 is an apparatus including means for implementing any one of Examples 1-57. Example 60 is a system for implementing any one of Examples 1-57. Example 61 is a method for implementing any one of Examples 1-57.

[0188] The detailed description above includes references to the accompanying drawings that form a part of the detailed description. The drawings illustrate, by way of example, specific examples in which the invention may be practiced. These examples may include elements in addition to those shown or described. However, the inventors also contemplate examples that provide only those elements shown or described. In addition, the inventors also contemplate examples using any combination or arrangement of those elements (or one or more aspects thereof), either with respect to a particular example (or one or more aspects thereof), or with respect to other examples shown or described herein (or one or more aspects thereof).

[0189] If there is any inconsistency in the usage between this document and any document incorporated by reference as such, the usage in this document shall prevail.

[0190] In this document, the terms "a" or "an", as is common in patent documents, are used to include one or more than one, independent of any other instances or uses of "at least one" or "one or more". In this document, the term "or" is used to mean an inclusive or, so that unless otherwise stated, "A or B" includes "A but not B", "B but not A", and "A and B". In this document, the terms "including" and "in which" are used as the plain English equivalents of the respective terms "comprising" and "wherein". Further, in the appended claims, the terms "including" and "comprising" are open-ended, i.e., a system, apparatus, article, composition, formulation, or process that includes elements in addition to those listed after such terms in a claim is still considered to fall within the scope of that claim. Further, in the appended claims, terms such as "first", "second", and "third" are used merely as labels and are not intended to impose numerical requirements on their objects.

[0191] The above description is intended to be illustrative, not restrictive. For example, the above examples (or one or more aspects thereof) may be used in combination with each other. After reviewing the above description, other examples may be used by those of ordinary skill in the art. The abstract is provided in accordance with 37 C.F.R. § 1.72(b) to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Further, in the above detailed description, various features may be combined to simplify the disclosure. This should not be construed as intending that the disclosed features that are not claimed are essential to any claim. On the contrary, the subject matter of the invention may lie in less than all of the features of a particular disclosed example. Thus, the appended claims are hereby incorporated into the detailed description as examples or one or more examples, where each claim stands on its own as a separate example, and it is contemplated that these examples may be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims in view of the full scope of equivalents to which such claims are entitled.

Claims

1. A system for distributing electrical energy, the system comprising: A first set of electric devices; A second set of electric devices; A first battery system, the first battery system being coupled to one or more of the first set of electric devices; A first fuel cell, the first fuel cell being coupled to one or more of the first set of electric devices; A second battery system, the second battery system being coupled to one or more of the second set of electric devices; And A second fuel cell, the second fuel cell being coupled to one or more of the second set of electric devices.

2. The system according to claim 1, wherein, The first fuel cell is coupled to the first battery system to charge the first battery system.

3. The system according to claim 1, wherein The first fuel cell is coupled to the second battery system to charge the second battery system.

4. The system according to claim 1, further comprising a set of propulsion systems, each propulsion system in the set of propulsion systems having an electric device from the first set of electric devices coupled thereto and an electric device from the second set of electric devices coupled thereto.

5. The system according to claim 4, wherein, One or more of the first set of electric devices coupled to the first fuel cell and one or more of the second set of electric devices coupled to the first fuel cell cumulatively supply power to all of the propulsion systems such that all of the propulsion systems can be powered by the first fuel cell and the second fuel cell together.

6. The system according to claim 4, wherein, One or more of the first set of electric devices coupled to the first battery system and one or more of the first set of electric devices coupled to the second battery system cumulatively supply power to all of the propulsion systems such that all of the propulsion systems can be powered by the first battery system and the second battery system together.

7. The system according to claim 5, wherein, One or more of the first set of electric devices coupled to the first battery system and one or more of the first set of electric devices coupled to the second battery system cumulatively supply power to all of the propulsion systems such that all of the propulsion systems can be powered by the first battery system and the second battery system together.

8. The system according to claim 4, wherein During operation, the first fuel cell and the second fuel cell power the set of propulsion systems during steady-state operation.

9. The system according to claim 8, wherein During operation, the first fuel cell and the second fuel cell recharge the first battery system and the second battery system during steady-state operation.

10. The system according to claim 6, wherein, During operation, the first battery system and the second battery system supply power to the set of propulsion systems during high-power operation of the propulsion systems.

11. The system according to claim 10, wherein, During operation, the first fuel cell and the second fuel cell also supply power to the set of propulsion systems during high-power operation of the propulsion systems.

12. The system according to claim 8, wherein, During operation, the first battery system and the second battery system supply power to the set of propulsion systems during high-power operation of the propulsion systems.

13. The system according to claim 12, wherein, During operation, the first fuel cell and the second fuel cell also supply power to the set of propulsion systems during high-power operation of the propulsion systems.

14. The system according to claim 9, wherein Steady-state operation is a horizontal flight mode in an aircraft.

15. The system according to claim 10, wherein, High-power operation is a vertical flight mode in an aircraft.

16. The system according to claim 10, wherein, The first battery system and the second battery system each include a plurality of batteries, and each of the plurality of batteries in each of the first battery system and the second battery system is coupled to a different electric device among the first set of electric devices and the second set of electric devices.

17. A method of operating a system for distributing electrical energy, the system comprising a first set of electrical devices; a second set of electrical devices; a first battery system coupled to one or more of the first set of electrical devices; a first fuel cell coupled to one or more of the first set of electrical devices; A second battery system, the second battery system being coupled to one or more of the second set of electric devices; a second fuel cell, the second fuel cell being coupled to one or more of the second set of electric devices; And a set of propulsion systems, each of the set of propulsion systems having an electric device from the first set of electric devices coupled thereto and an electric device from the second set of electric devices coupled thereto, the method comprising: Powering the set of propulsion systems using the first fuel cell and the second fuel cell during steady-state operation; And Powering the set of propulsion systems at least in part using the first battery system and the second battery system during high-power operation.

18. The method according to claim 17, further comprising: Powering the set of propulsion systems at least in part using the first fuel cell and the second fuel cell during high-power operation.

19. The method according to claim 17, further comprising: Recharging the first battery system and the second battery system during steady-state operation.

20. The method according to claim 17, wherein Steady-state operation is a horizontal flight mode in an aircraft, and high-power operation is a vertical flight mode in an aircraft.

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