Hybrid Electric Architecture

Abstract

The aircraft hybrid power distribution system includes first and second sets of electrically powered devices, such as inverters, motors, etc. A first battery system is coupled to one or more of the first set of electrically powered devices, and a first fuel cell is coupled to one or more of the first set of electrically powered 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. Together, the fuel cell and the battery provide power to the electrically powered devices as needed while maintaining the battery in a charged state.

Description

[Technical Field]

[0001] The present subject matter relates to hybrid architectures. More particularly, but not by way of limitation, the present disclosure relates to hybrid electric architectures including battery and fuel cell systems for powering aircraft. The present invention relates generally to the field of aviation, and more particularly to hybrid architectures for electric aircraft. [Background technology]

[0002] There is currently a drive to transition away from internal combustion engines, turbines, and other propulsion means that utilize fossil fuels. The use of electric propulsion and batteries may be limited because current batteries have a lower energy density than fuel tanks that hold the same volume of fossil fuel. In other words, a battery with the same size as a gas tank may not have the energy storage capacity to propel a car the same distance.

[0003] A fuel cell is an electrochemical cell that converts the chemical energy of a fuel (often hydrogen) and an oxidant (often oxygen) into electricity through a pair of oxidation-reduction reactions. Fuel cells are used to generate electrical power 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 inaccessible areas. Fuel cells are also used to power fuel-cell-powered vehicles, including forklifts, cars, buses, trains, boats, motorcycles, and submarines.

[0004] Fuel cell vehicles are powered by hydrogen supplied to an on-board fuel cell "stack," which converts the hydrogen's chemical energy into electrical energy that can then be used to power the vehicle and its on-board systems.

[0005] Hydrogen fed into the fuel cell enters the anode, where it comes into contact with a catalyst that promotes the separation of hydrogen atoms into electrons and protons. The electrons are collected by a conductive current collector connected to the vehicle's high-voltage circuit and supplied to the onboard battery and / or electric motor that propels the vehicle. A by-product of the reaction occurring within the fuel cell stack is water vapor, which is released through the exhaust.

[0006] A fuel cell powered vehicle also includes a "balance of plant" which includes all of the other components of the fuel cell system except the stack itself, such as pumps, sensors, heat exchangers, gaskets, compressors, recirculation blowers or humidifiers. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a plan view of an aircraft, according to some examples. [Figure 2] FIG. 2 is a schematic diagram of an aircraft energy system used in the aircraft of FIG. 1 , according to some examples. [Figure 3] FIG. 2 is a schematic diagram of an aircraft energy system used in the aircraft of FIG. 1 , according to some examples. [Figure 4] 2 is a schematic diagram illustrating a hydrogen fuel cell system used in the aircraft of FIG. 1, according to some examples. [Figure 5] 1 illustrates an aircraft having a hybrid-electric architecture system, according to some examples. [Figure 6] 1 illustrates an aircraft having a hybrid-electric architecture system, according to some examples. [Figure 7] 1 illustrates an aircraft having a hybrid-electric architecture system, according to some examples. [Figure 8A] FIG. 1 is a perspective view of an aircraft in a vertical propulsion configuration, according to some examples. [Figure 8B] FIG. 1 illustrates a perspective view of an aircraft in a horizontal propulsion configuration, according to some examples. [Figure 9A]1 illustrates tilting of an aircraft propulsion system and associated components such as a propeller and nacelle, according to some examples. [Figure 9B] 1 illustrates tilting of an aircraft propulsion system and associated components such as a propeller and nacelle, according to some examples. [Figure 9C] 1 illustrates tilting of an aircraft propulsion system and associated components such as a propeller and nacelle, according to some examples. [Figure 10A] 1 illustrates tilting of an aircraft propulsion system and associated components such as a propeller and nacelle, according to some examples. [Figure 10B] 1 illustrates tilting of an aircraft propulsion system and associated components such as a propeller and nacelle, according to some examples. [Figure 10C] 1 illustrates tilting of an aircraft propulsion system and associated components such as a propeller and nacelle, according to some examples. [Figure 11] 1 is a flowchart illustrating a method for powering a propulsion system of an aircraft, according to some embodiments. [Figure 12] 1 illustrates, according to some examples, a schematic diagram of a machine in the form of a computer system upon which a set of instructions may be executed to cause the machine to perform any one or more of the methodologies described herein. DETAILED DESCRIPTION OF THE INVENTION

[0008] In the drawings, which are not necessarily drawn to scale, like numerals may describe like components in different views. Like numerals with different letter suffixes may represent different instances of like components. These drawings generally illustrate, by way of example, and not by way of limitation, various examples discussed in this document.

[0009] Aircraft and other vehicles can utilize battery technology for propulsion instead of burning fossil fuels. For example, aircraft and automobiles may use electric motors for propulsion, and batteries can be used for energy storage. Electric motors offer the advantage of being quieter compared to internal combustion engines or turbines. Additionally, batteries can quickly increase or decrease their power supply in response to electrical loads.

[0010] Aircraft and other vehicles that utilize battery technology for propulsion instead of burning fossil fuels may have range limitations due to the lower energy density of batteries compared to fossil fuels. Stated differently, given the size and weight limitations imposed on batteries, batteries may only contain enough energy for short distance travel compared to a fuel tank of equivalent volume.

[0011] Fuel cell systems, such as hydrogen fuel cell systems, can be used to power electrical components. However, fuel cell systems may have limitations in that they cannot quickly increase or decrease the power they supply to account for changes in the load on the electrical components. For example, an electric motor commanded to rapidly increase power may exceed the power response speed of the fuel cell system.

[0012] As disclosed herein, batteries can be used to power electrically powered devices such as electric motors, and fuel cell systems can be used to keep the batteries charged while traveling. The batteries can provide a constant or near-constant voltage to the electrical components and can also adequately supply power due to current spikes that may be caused by increased loads on the electrical components.

[0013] Consistent with examples disclosed herein, batteries may be used to power electrical components, while a fuel cell system may also be used to power the electrical components and keep the batteries charged. The fuel cell system may be a hydrogen fuel cell system. Hydrogen may have a higher energy density than batteries alone. Thus, hydrogen stored in tanks may provide more energy than batteries of comparable mass and / or volume. As a result, smaller batteries may be used to power electrically powered devices while the fuel cell system recharges them, thereby increasing the range and utility of vehicles such as aircraft.

[0014] The above description is intended to provide an overview of the subject matter of this patent application. It is not intended to provide an exclusive or exhaustive description of the invention. The following description is included to provide further information about this patent application.

[0015] FIG. 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 embodied as a tiltable rotor assembly 116 located in a nacelle 118. The aircraft 100 includes multiple nacelle battery packs 104, one or more power sources embodied in FIG. 1 as multiple wing battery packs 106, and a fuel cell 122. In the illustrated example, the nacelle battery pack 104 is disposed in the inner nacelle 102, although it will be understood that the nacelle battery pack 104 may be disposed in another nacelle 118 forming part of the aircraft 100. The battery packs form part of an energy system 200, which will be described with reference to FIG. 2, and the fuel cell 122 forms part of a fuel cell system 300, which will be described with reference to FIG. 3. The nacelle battery pack 104, wing battery pack 106, fuel cell 122, and propulsion system 108 are interconnected and function as described below with reference to Figures 5, 7, and / or 7. The aircraft 100 typically includes associated equipment such as electronic infrastructure, control surfaces, cooling systems, landing gear, etc.

[0016] The wings 112 function to generate lift that supports the aircraft 100 during forward flight. The wings 112 may also or alternatively function to structurally support the battery packs 202, battery modules 204, and / or propulsion system 108 under various structural stresses (e.g., aerodynamic forces, gravity, thrust forces, external point loads, distributed loads, and / or volume forces, etc.). The wings 112 may have any suitable geometry and / or arrangement on the aircraft.

[0017] 2 is a schematic diagram of an aircraft energy system 200 for use with the aircraft 100 of FIG. 1, according to some examples. 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, which may include multiple cells 206.

[0018] 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 of the energy system 200, a burst membrane 210 as part of a ventilation system, a fluid circulation system 212 for cooling, and power electronics 214 for regulating the delivery of electrical power (from the operating battery to the charging battery) and providing integration of the battery pack 202 with the electronic infrastructure of the energy system 200. As shown in FIG. 1 , the propulsion system 108 may comprise multiple rotor assemblies.

[0019] Electronic infrastructure and power electronics 214 may additionally or alternatively function to integrate battery pack 202 into the aircraft's energy system. The electronic infrastructure may include a battery management system (BMS), power electronics (HV architecture, power components, etc.), LV architecture (e.g., vehicle wiring harnesses, data connections, etc.), and / or 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 connections may include bulkhead connections, bus bars, wiring harnesses, and / or other suitable components.

[0020] The battery packs 202 function to rechargeably store electrochemical energy for supplying the propulsion system 108. The battery packs 202 may be positioned and / or distributed in any suitable manner relative to the aircraft. The battery packs may be positioned within the wings (e.g., inside the airfoil cavities), within the nacelles, and / or in any other suitable location on the aircraft. In a particular example, the system includes a first battery pack within an inner portion of the left wing and a second battery pack within an inner portion of the right wing. In a second particular example, the system includes a first battery pack within an inner nacelle of the left wing and a second battery pack within an inner nacelle of the right wing. The battery packs 202 may include multiple battery modules 204.

[0021] The battery system 200 includes a cooling system (e.g., fluid circulation system 212) that functions to circulate a working fluid within the battery pack 202 to remove heat generated by the battery pack 202 during operation or charging. The battery cells 206, battery modules 204, and / or battery pack 202 may be fluidly connected by the cooling system in any suitable manner in series and / or parallel.

[0022] 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.

[0023] 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 the fuel cell 314, a coolant fluid circulation system 308 for transferring heat, power electronics 310 for regulating the supply of power from the fuel cell 314 during operation and for 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.

[0024] The electronic infrastructure may include an energy supply management system 302 for monitoring and controlling the operation of the fuel cell 314 . The fuel cells 314 function to convert chemical energy into electrical energy to supply the propulsion system 108 and to charge the battery packs 202. The fuel cells 314 may be positioned and / or distributed throughout the aircraft in any suitable manner. The fuel cell stacks may be located within the wings (e.g., inside the airfoil cavities), inside the nacelles, and / or in any other suitable location on the aircraft.

[0025] Fuel cell system 300 may optionally include a heat transfer system (e.g., fluid circulation system 308) for transferring heat from or to various components of aircraft 100, for example, by circulating a working fluid within fuel cell 314 to remove heat generated during operation, by providing heat for evaporating liquid hydrogen from liquid hydrogen tank 402, or by removing heat from other heat-generating components within aircraft 100, and / or functions in this manner.

[0026] 4 is a schematic diagram illustrating 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.

[0027] Liquid hydrogen tank 402, as the name suggests, stores liquid hydrogen for use in fuel cell 406. Liquid hydrogen tank 402 is connected to and supplies liquid hydrogen to heat exchanger 408, which adds heat to the hydrogen before supplying it to fuel cell 406.

[0028] The heat exchanger 408 provides cooling via a coolant loop 416 to other systems that generate heat, such as the fuel cell 406, or to the compressor 404 used to compress oxygen-containing air for use by the fuel cell 406. The coolant loop 416 contains a coolant liquid that can be circulated to and from a heat source (not shown) to cool the heat source. In some examples, the cold hydrogen gas exiting the liquid hydrogen tank 402 can more directly cool a heat source, such as the compressor 404, for example, by locating the heat exchanger 408 at or near the heat source.

[0029] The compressor 404 compresses ambient air 418 to the pressure required by the fuel cell 406 to supply it to the fuel cell. Compressing the ambient air 418 increases its temperature. Therefore, coolant from the coolant loop 416 can be used to pre-cool the ambient air 418 at the inlet to the compressor 404 or to cool the compressor 404 itself. Supplying cooler air to the compressor 404 reduces its power consumption. The air exiting the compressor 404 may be cooled or further cooled by an intercooler 420 before being supplied to the fuel cell 406.

[0030] The warmer hydrogen gas exiting heat exchanger 408 is received by the fuel cell, which, along with compressed air received from compressor 404, produces power 410, heat 412, and water vapor exhaust 414, as known in the art. Heat 412 generated by operation of fuel cell 406 is removed by coolant flowing through heat exchanger 422 as part of warming loop 424.

[0031] In some examples, the coolant loop 416 is also used to cool the fuel cell 406 in addition to, or instead of, cooling the ambient air 418 or the compressor 404. Other methods for cooling the fuel cell 406 or the air supplied thereto may also be used.

[0032] 5 illustrates an aircraft 500 in accordance with at least one example of the present disclosure. Aircraft 500 may include a fuselage 501, wings 502a and 502b, horizontal stabilizers 503a and 503b, nacelles 504a, 504b, 504c, 504d, 504e, and 504f, and power distribution lines 505a, 505b, 505c, and 505d.

[0033] As disclosed herein, aircraft 500 may be powered by batteries 506a, 506b, 506c, and 506d and fuel cells 507a and 507b. Batteries 506a-506d and fuel cells 507a and 507b may be connected to first electric devices 508a, 508b, 508c, 508d, 508e, and 508f and second electric devices 509a, 509b, 509c, 509d, 509f, and 509e. Non-limiting examples of first electric devices 508a-508f and second electric devices 509a-509f include inverters, electric motors, sets of coils of electric motors, DC / DC converters, DC / AC inverters, and any combination thereof. For example, one or more of the first electrical devices 508a-508f may be an inverter that converts direct current (DC) electricity into alternating current (AC) electricity for powering one or more electric motors.

[0034] One or more of the first electrical devices 508a-508f may also be a DC / DC converter that converts a first DC voltage (e.g., the voltage generated by a fuel cell) to a second DC / DC voltage (e.g., the voltage needed to drive an electric motor. The electric motor can then rotate one or more propellers and / or rotors of the aircraft, thereby generating thrust. Still consistent with the examples presented in this disclosure, the batteries 506a-506d and fuel cells 507a and 507b may directly supply electricity to the motors and / or other electrical components without requiring the use of an inverter.

[0035] As disclosed herein, the combination of batteries 506a-506d and fuel cells 507a and 507b provides redundancy. In some examples, the first battery 506a, the third battery 506c, and the first fuel cell 507a may supply electricity to first electric devices 508a-508e. The second battery 506b, the fourth battery 506d, and the second fuel cell 507b may supply electricity to second electric devices 509a-509f. In this example, the first electric devices 508a-508e and the second electric devices 509a-509f are inverters that supply electricity to electric motors. 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. The second distribution system is therefore a redundant distribution system, and either the first distribution system or the second distribution system can power the aircraft in the event that the other distribution system fails.

[0036] In some examples, the batteries 506a-506d supply battery voltages to both the first electrical devices 508a-508e and the second electrical devices 509a-509f. The battery voltages from each of the batteries 506a-506d may be the same or different. For example, each of the batteries 506a-506d may supply a constant 48V. Still consistent with examples disclosed herein, the first battery 506a and the third battery 506c may supply 24V, while the second battery 506b and the fourth battery 506d may supply 26V.

[0037] In some examples, the fuel cells 507a, 507b provide a charging voltage to the batteries 506a-506d. For example, during operation, the batteries 506a-506d may provide a voltage such as 48V to the first and second electrical devices 508a-508e, 509a-509f, which may be electric motors or inverters for electric motors, depending on the implementation. To keep the batteries 506a-506d charged, the fuel cells 507a, 507b may provide a charging voltage to the batteries 506a-506d, which may be 60V or some other voltage.

[0038] Electric motors and other electrical devices require a constant voltage but may draw varying current. Batteries 506a-506d can provide a constant voltage while also appropriately increasing or decreasing current or power output as needed based on the load of the electrical device. In some examples, fuel cells 507a, 507b recharge batteries 506a-506d as they become depleted during use.

[0039] Each of the six motors in the propulsion system 108 has two sets of windings, and each motor is powered by two inverters, one inverter for each set of windings. In addition to powering the propulsion system 108, the batteries 506a-506d and fuel cells 507a, 507b also power the rotor deployment mechanisms (nacelle tilt actuators) used to position the rotor 120 during various flight modes (vertical takeoff and landing configurations, forward flight configurations, and transitions between them).

[0040] Batteries 506a-506d and fuel cells 507a, 507b also power the blade pitch motors and position encoders (with variable pitch) of rotor 120, flight control surface actuators used to position various flight control surfaces on aircraft 100, and the avionics suite. The blade pitch motors and flight control surface actuators receive power that flows through one of DC / DC converters 606a-606d, which can step down or step up the voltage from the battery or fuel cell voltage as appropriate. The avionics suite is also coupled to the flight computers. The batteries 506a-506d can also be recharged via an external charger when aircraft 500 is on the ground.

[0041] 5, a first fuel cell 507a supplies power to a first battery 506a and a second battery 506b, while a second fuel cell 507b supplies power to a third battery 506c and a fourth battery 506d. The first battery 506a supplies power to a second electric device 509b, a first electric device 508d, and a second electric device 509e via a power distribution line 505a. The second battery 506b supplies power to a first electric device 508a, a second electric device 509c, and a second electric device 509f via a power distribution line 505b. The third battery 506c supplies power to a first electric device 508b, a second electric device 509d, and a second electric device 509e via a 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.

[0042] 6 illustrates a system 600 for distributing electric energy in accordance with at least one example of the present disclosure. System 600 may include power distribution lines 601 a, 601 b, 601 c, and 601 d, batteries 602 a, 602 b, 602 c, and 602 d, and fuel cells 603 a and 603 b. In some examples, batteries 602 a-602 d and fuel cells 603 a and 603 b are connected to first electric devices 604 a, 604 b, 604 c, 604 d, 604 e, and 604 f and second electric devices 605 a, 605 b, 605 c, 605 d, 605 e, and 605 f.

[0043] Non-limiting examples of the first electric devices 604a-604f and second electric devices 605a-605f may include inverters, converters, electric motors, sets of coils of electric motors, and any combination thereof. As disclosed herein, electric devices such as the first electric devices 604a-604f may be inverters that convert direct current (DC) electricity to alternating current (AC) electricity to power one or more electric motors that rotate rotors to generate thrust. Still consistent with the examples presented in this disclosure, batteries 602a-602d and fuel cells 603a, 603b can directly supply electricity to motors and / or other electrical components without requiring the use of inverters. In some examples, electric devices are paired (e.g., first electric device 604a and second electric device 605a, first electric device 604b and second electric device 605b), whereby each pair supplies power to an electric motor in a respective propulsion system 108. In some examples, each pair of electrical devices powers a different set of coils in the motor, providing additional redundancy in the event that a set of coils in the motor fails.

[0044] As disclosed herein, during operation, the first electric devices 604a-604f and the second electric devices 605a-605f may operate at a constant or near-constant power draw. However, during various stages of operation, the external loads on the first electric devices 604a-604f and the second electric devices 605a-605f may change. For example, during the forward flight or hovering portion of flight, the load on the electric motors driving the rotors may be relatively constant. However, during takeoff, or during a transition from hovering to forward motion or during a maneuver, such as rotating the rotors from a vertical position to a horizontal position, the load on the electric motors may increase dramatically for a short period of time.

[0045] An increase in load over a short period of time can cause an increase in current draw. As disclosed herein, the fuel cells 603a, 603b may not be able to generate the required power for a short period of time or at the required power level. However, the batteries 602a-602d are able to provide the necessary power. Thus, during high-power operation, the batteries 602a-602d can power the motors or inverters driving the motors (i.e., the first electrical devices 604a-604f and the second electrical devices 605a-605f) to supplement or replace the power provided by the fuel cells 603a, 603b. To extend operation beyond the initial charge the batteries 602a-602d may have, the fuel cells 603a, 603b can continuously or intermittently recharge the batteries 602a-602d during steady-state operation, such as during level flight, when excess power is available from the fuel cells 603a, 603b.

[0046] System 600 may incorporate redundancy. As shown in Figure 6, each of batteries 602a-602d powers three separate ones of first electrical devices 604a-604f and second electrical devices 605a-605f. In other words, each of batteries 602a-602d powers a subset of first electrical devices 604a-604f and second electrical devices 605a-605f.

[0047] As disclosed herein, during operation, each of the batteries 602a-602d may supply a first battery voltage to each of a first subset of the first electrical devices 604a-604f and second electrical devices 605a-605f. Each of the batteries 602a-602d may supply a second battery voltage to each of a second subset of the first electrical devices 604a-604f and / or second electrical devices 605a-605f.

[0048] 6, first electric devices 604a-604f and second electric devices 605a-605f may be inverters used to power electric motors of electric vertical take-off and landing (eVTOL) air vehicle 100. One of each of first electric devices 604a-604f and second electric devices 605a-605f may be disposed in nacelle 118 of eVTOL air vehicle 100 to power propulsion system 108. Thus, second electric devices 605a-605f may be backup devices for first electric devices 604a-604f.

[0049] As shown in FIG. 6, each of batteries 602a-602d powers three electric devices. The various first electric devices 604a-604f and second electric devices 605a-605f may be configured to be disposed within various nacelles of an aircraft, such as aircraft 100, 500. Accordingly, FIG. 6 may represent a six-rotor eVTOL aircraft 100 having batteries 602a and 602b powering each of six motors corresponding to the six rotors 120, and batteries 602c and 602d powering each of six motors corresponding to the six rotors 120. Thus, batteries 602c and 602d and fuel cell 603b can function as a redundant system for batteries 602a and 602b and fuel cell 603a, and vice versa.

[0050] System 600 may also include DC / DC converters 606a, 606b, 606c, and 606d. DC / DC converters 606a-606d, in some examples, are in electrical communication with batteries 602a-602d and fuel cells 603a-603b. In operation, DC / DC converters 606a-606d, in some examples, convert the fuel cell output voltage from fuel cells 603a-603b to a battery charging voltage. For example, fuel cells 603a-603b may output approximately 60V, which may be constant or fluctuating. DC / DC converters 606a-606d convert or otherwise regulate the output from fuel cells 603a-603b to a constant voltage, referred to as a charging voltage, such as 48V, so that fuel cells 603a-603b can provide a constant voltage to batteries 602a-602d for charging.

[0051] The voltage generated by batteries 602a-602d may be the same or different for each battery. For example, if each of batteries 602a-602d is used to power an electric motor for a respective rotor, 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 if any of batteries 602a-602d is used to power other components, such as avionics, lighting, etc., that may operate at a different voltage than the rotor, the output voltage of each battery may be different from the output voltage of the other batteries. In other words, while FIG. 6 shows an example in which batteries 602a-602d are used to power rotors that may have the same input voltage requirements, any one or combination of batteries 602a-602d may be used to power other electrical devices that have different input voltage requirements, and therefore any one or combination of batteries 602a-602d may provide different input voltages as needed.

[0052] Fuel cells 603a, 603b may also supply the same or different voltages to one or more of batteries 602a-602d or DC / DC converters 606a-606d. For example, fuel cell 603a may supply a first voltage to DC / DC converters 606a and 606b, while fuel cell 603b may supply a second voltage to DC / DC converters 606c and 606d. The first and second voltages, referred to as charging voltages, may be the same or different.

[0053] As disclosed herein, the first electric devices 604a-604f and the second electric devices 605a-605f may be divided into subsets of electric devices. For example, electric devices 605b, 604d, and 605e may comprise a first subset of electric devices, and electric devices 604b, 605d, and 604e may comprise a second subset of electric devices. Thus, the first electric devices 604a and 604b may, in some examples, be electric devices of a common function (e.g., inverters driving a common motor for a rotor).

[0054] 6, a first fuel cell 603a supplies power to a first battery 602a via a DC / DC converter 606a and to a second battery 602b via a DC / DC converter 606b. The second fuel cell 603b supplies power to a third battery 602c via a DC / DC converter 606c and to a fourth battery 602d via a DC / DC converter 606d. The first battery 602a supplies power to a second electric device 605b, a first electric device 604d, and a second first electric device 604e via a power distribution line 601a. ​​The second battery 602b supplies power to a first electric device 604a, a second electric device 605c, and a second second electric device 605f via a power distribution line 601b. The third battery 506c supplies power to the first electric device 604b, the second electric device 605d, and the second electric device 605e via the power distribution line 601c. The fourth battery 602d supplies power to the second electric device 605a, the first electric device 604c, and the first electric device 604f via the power distribution line 601d.

[0055] 6 for clarity, in some examples, fuel cell 603a and fuel cell 603b are also coupled to a subset of first electric devices 604a-604f and second electric devices 605a-605f. In such cases, one of each of the two electric devices for a particular propulsion system 108 is coupled to either first fuel cell 122 or second fuel cell 122, such that aircraft 100 may be powered primarily or completely by fuel cells 603a, 603b during steady-state operation, such as when in forward flight mode. Additionally, redundancy is provided by coupling the first fuel cell 603a to the electric devices (first electric device 604b, second electric device 605d, second electric device 605e, second electric device 605a, first electric device 604c, and first electric device 604f) to which the third battery 602c and fourth battery 602d are coupled, and by coupling the second fuel cell 603b to the electric devices (second electric device 605b, first electric device 604d, first electric device 604e, first electric device 604a, second electric device 605c, and second electric device 605f) to which the first battery 602a and second battery 602b are coupled, such that all of the propulsion system 108 may be powered by independent and redundant sets of fuel cells and two batteries.

[0056] 6 shows batteries 602a and 602c powering a common device (i.e., the same rotor), batteries 602a and 602c may power different components. For example, battery 602a may power electric devices 605b, 604c, and 605e, while battery 602b may power electric devices 604a, 605c, and 605f. Thus, batteries 602a-602d and fuel cells 603a, 603b can provide cross-redundancy for first electric devices 604a-604f and second electric devices 605a-605f.

[0057] 7 shows a system 700 for distributing electric energy, according to some examples. System 700 may include power distribution lines 701 a, 701 b, 701 c, and 701 d, batteries 702 a and 702 b, and fuel cells 703 a and 703 b. Batteries 702 a, 702 b, and fuel cells 703 a, 703 b may be connected to first electric devices 704 a, 704 b, 704 c, 704 d, 704 e, and 704 f) and second electric devices 705 a, 705 b, 705 c, 705 d, 705 e, and 705 f.

[0058] Non-limiting examples of the first electric devices 704a-704e and second electric devices 705a-705e include inverters, converters, electric motors, and any combination thereof. As disclosed herein, an electric device such as the first electric devices 704a-704e may be an inverter that converts direct current (DC) electricity to alternating current (AC) electricity to power one or more electric motors that rotate rotors that generate thrust. While remaining consistent with the examples presented in this disclosure, the batteries 702a-702b and fuel cells 703a, 703b can directly supply electricity to the motors and / or other electric components without requiring the use of inverters.

[0059] 7, fuel cells 703a, 703b directly supply power to first electrical devices 704a-704e and second electrical devices 705a-705e. In this example, first electrical devices 704a-704e and second electrical devices 705a-705e, or a subset thereof, may operate solely on power provided by fuel cells 703a, 703b.

[0060] Each of the first electric devices 704a-704e and second electric devices 705a-705e is located at a respective location representing a location for the rotor of the eVTOL aircraft 100. As shown in Figure 7, at each location, each of the first electric devices 704a-704e is powered by one of the batteries 702a, 702b, and each of the second electric devices 705a-705e is powered by a fuel cell 703a, 703b. During steady-state operation, where the draw power may be uniform or otherwise constant, the fuel cells 703a, 703b can provide power to the rotor while allowing the batteries 702a, 702b to remain charged. During transient operations, such as transitioning from hover to cruise flight, when current draw can spike, the batteries 702a, 702b can provide the necessary power for the various rotors because they can easily provide increased power in a responsive manner that may not be possible with fuel cells. Additionally, by using batteries to supply or top up power to peak levels, the fuel cell system can have a lower peak capacity, making it lighter and smaller.

[0061] The fuel cells 703a, 703b may also power the batteries 702a, 702b via DC / DC converters 706a and 706b. Thus, the fuel cells 703a, 703b may recharge the batteries 702a, 702b during steady-state operation, as disclosed herein. Thus, during transient operation when increased power may be required, the batteries 702a, 702b may be discharged to provide additional power.

[0062] 7, a first fuel cell 703a supplies power to a first battery 702a via a DC / DC converter 706a, and supplies power to a first electric device 704a, a second electric device 705c, and a second electric device 705f via a power distribution line 701c. A second fuel cell 703b supplies power to a second battery 702b via a DC / DC converter 706b, and supplies power to a first electric device 704b, a second electric device 705d, and a first electric device 704e via a power distribution line 701d. A first battery 702a supplies power to a second electric device 705b, a first electric device 704d, and a second electric device 705e via a 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.

[0063] As disclosed herein, the battery 702a, the fuel cell 703a, and a subset of the first electrical devices 704a-704e and second electrical devices 705a-705e are a first power distribution system, and the battery 702b, the fuel cell 703b, and another subset of the first electrical devices 704a-704e and second electrical devices 705a-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-704e and second electrical devices 705a-705e.

[0064] FIG. 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 with the same or different types of propulsion system 108 adapted for both vertical takeoff and landing and forward flight. As shown in FIG. 8AA, 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 adapted to articulate from a forward flight configuration to a vertical flight configuration using a deployment mechanism that may be present in a nacelle 118, deploying the motor and rotor 120 while all or most of the nacelle remains in place attached to the wing. In some aspects, the propeller blades may be housed and nested within the nacelle body. The motor-driven propulsion system 108 at the wingtip can deploy along a pivot axis from a forward flight configuration to a vertical takeoff and landing configuration, with the nacelle 118, electric motor, and rotor 120 deploying in unison. Although shown as having one mid-span propulsion system and one wingtip propulsion system, in some embodiments there may be more mid-span propulsion assemblies.

[0065] The aircraft fuselage 114 extends aft and is attached to a tail section 110. The tail section 110 has attached to it an aft propulsion system 108. The motor-driven propulsion system 108 at the tip of the tail section 110 also deploys along a pivot axis from a forward flight configuration to a vertical takeoff and landing configuration, with the nacelles, electric motors, and propellers deploying in unison.

[0066] 8B is a perspective view of the aircraft 100 in a horizontal thrust configuration, in which the propulsion system 108 is positioned or configured to provide forward thrust during horizontal flight, according to some examples.

[0067] 9A, 9B, and 9C illustrate the tilt of propulsion system 108 and associated components, such as propeller 902 and nacelle 904, according to some examples. The aircraft is preferably an eVTOL aircraft 100 (e.g., a multimodal aircraft) as shown, but may additionally or alternatively include any suitable aircraft. Aircraft 100 is preferably a tilt-rotor aircraft having multiple aircraft propulsion systems operable between a forward configuration ( FIGS. 9A and 10A ) and a hovering or vertical flight configuration ( FIGS. 9C and 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., at least one rotor assembly or aircraft propulsion system is oriented substantially axially to provide horizontal thrust), a tilt-wing aircraft, a wingless aircraft (e.g., a helicopter, multicopter, quadcopter), and / or any other suitable rotary-wing aircraft or vehicle propelled by propellers or rotors.

[0068] As shown in Figures 9A-9C, in one example, a nacelle 904 including an aircraft propulsion system 108 (including a motor, two power inverters, and a radiator) and a propeller 902 having a blade pitching mechanism 908 is tilted relative to the rest of the aircraft 100 by a tilt mechanism 906 located toward the rear of the nacelle 904.

[0069] When integrated into a propulsion ramp mechanism in an aircraft configurable between forward and hover configurations, the cooling subsystem can advantageously take advantage of the increased airflow available in the hover configuration, as discussed below.

[0070] 10A, 10B, and 10C illustrate the tilting 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 Figures 10B and 10C, in this example, the aircraft propulsion system 108 (including a motor, two inverters, and a radiator) and the propeller 1002 with a blade pitching mechanism 1008 are tilted relative to the nacelle 1004 by a tilt mechanism 1006 located toward the front of the nacelle 1004.

[0071] 11 is a flowchart 1100 illustrating a method of powering 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 sequentially or linearly. However, multiple operations of the flowchart 1100 may 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 may be replaced by other operations. The operations of the flowchart 1100 may be performed, alone or in combination, by the power electronics 214, the power electronics 310, the energy supply management system 302, or another computing device located within the aircraft 100.

[0072] Flowchart 1100 begins with operation 1102 in which aircraft 100 operates in fuel cell mode, in which the aircraft, and in particular its propulsion system 108, is powered solely by fuel cells 122. This may be, for example, when aircraft 100 is in forward flight at a constant cruising speed and altitude. Alternatively, the aircraft may be on the ground with the rotors stationary and the avionics and other systems powered solely by the fuel cells.

[0073] In operation 1104, a control input or command is received from a pilot or from an autonomous system operating the aircraft 100. In operation 1106, it is determined whether the power required to execute the control input or command has exceeded or will exceed a predetermined threshold, or whether the rate of power increase will exceed a predetermined threshold. This may be determined dynamically by monitoring the power drawn by the propulsion system and / or the rate of change of the drawn power, the voltage and / or frequency of the power signal, or may be determined predictively or contextually, for example, based on the location of the aircraft, whether the nacelle 118 is in a vertical or horizontal thrust producing mode, based on the flight plan of the aircraft, or based on the nature of the command or instruction received.

[0074] If, in operation 1106, it is determined that the required power does not or will not exceed the threshold (e.g., if the aircraft 100 is in a forward flight mode and the command or instruction relates to a change in direction or indicates a descent), or as determined by monitoring the dynamic power, rate of change of retracted power, current, frequency, etc., flowchart 1100 returns to operation 1102 and the aircraft 100 continues operating in fuel cell mode.

[0075] If, in operation 1106, it is determined that the required power exceeds or will exceed a threshold (e.g., if the air vehicle 100 is on the ground and a command or instruction relates to powering the rotors for takeoff, or if the air vehicle is in forward flight and a command or instruction indicates entering a hover mode, or based on a parameter related to retract power), the air vehicle operates in battery mode in operation 1108. In battery mode, at least a portion of the power supplied to the propulsion system is supplied from batteries (such as the nacelle battery pack 104 and wing battery pack 106, or the batteries described with reference to FIGS. 5, 6, and 7).

[0076] In battery mode, the battery supplements the power provided to the propulsion system 108 so that power demands are met. This allows for continuous operation of the fuel cell 122 in a more stable manner without requiring rapid adjustments to the fuel cell's power output. In some examples, the battery may provide all of the power to one or more or all of the propulsion system 108. In operation 1110, a further control input is received.

[0077] At operation 1112, it is determined whether the power demanded by the propulsion system 108 continues to exceed the predetermined power threshold. If at operation 1112 it is determined that the power demanded no longer exceeds the threshold (e.g., the aircraft 100 transitions from a vertical thrust mode to a forward flight mode, resulting in a reduction in retracted power below the predetermined threshold), flowchart 1100 returns to operation 1102, and the aircraft 100 resumes operation in fuel cell mode.

[0078] If, in operation 1106, it is determined that the power demanded by the propulsion system 108 continues to exceed the predetermined threshold, the aircraft continues to operate in battery mode in operation 1108. In battery mode, at least a portion of the power supplied to the propulsion system is supplied from batteries (such as the nacelle battery pack 104 and the wing battery packs 106, or the batteries described with reference to FIGS. 5, 6, and 7).

[0079] Flowchart 1100 then continues from either operation 1102 or operation 1108, as appropriate. If the aircraft 100 is operating in fuel cell mode, then in operation 1114 it is also determined whether the fuel cells have extra capacity. If not, the aircraft 100 continues to operate in fuel cell mode in operation 1102. If in operation 1114 it is determined that the fuel cells have extra capacity, then in operation 1116 it is determined whether the batteries require charging. This determination depends primarily on the state of charge, but may also be based on other factors such as the flight plan and expected demand from the batteries, the charging history of individual batteries or battery packs, and the available hydrogen in the liquid hydrogen tanks 402. If the batteries require charging or charging is appropriate, then the batteries are charged in operation 1118 and the flowchart returns to operation 1102 and proceeds from there.

[0080] It will be understood that various alternatives are contemplated. In fully dynamic monitoring of the power, current, and / or frequency of power supplied to propulsion system 108, for example, receiving and evaluating control inputs in operations 1104 and 1110 is not strictly necessary, although as noted above, this can provide additional contextual or predictive data.

[0081] 12 shows a schematic diagram of a machine 1200 in the form of a computer system upon which a set of instructions may be executed to cause the machine to perform any one or more of the methodologies discussed herein, according to one example. For example, power electronics 214, power electronics 310, and energy supply management system 302 may be embodied as machine 1200.

[0082] Specifically, FIG. 12 illustrates a schematic diagram of a machine 1200, an exemplary form of computer system, within which instructions 1208 (e.g., software, programs, applications, applets, apps, or other executable code) may be executed to cause the machine 1200 to perform any one or more of the methods discussed herein. The instructions 1208 transform a general-purpose, unprogrammed machine 1200 into a specific machine 1200 programmed to perform the functions described and illustrated herein in the described manner. In alternative examples, the machine 1200 may operate as a standalone device or may be coupled (e.g., networked) to other machines. In a networked deployment, the machine 1200 may operate as a server or client machine in a server-client network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. Machine 1200 may 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 mobile phone, a smartphone, a mobile device, a wearable device (e.g., a smart watch), a smart home device (e.g., a smart appliance), other smart devices, a web appliance, a network router, a network switch, a network bridge, or any machine capable of executing instructions 1208, sequentially or otherwise, that specify actions to be taken by machine 1200. Furthermore, although only one machine 1200 is shown, the term "machine" should be taken to include a collection of machines 1200 that individually or collectively execute instructions 1208 to perform any one or more of the methodologies discussed herein.

[0083] Machine 1200 may include processor 1202, memory 1204, and I / O components 1242, which may be configured to communicate with each other, for example, via bus 1244. In one example, 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) may include, for example, processor 1206 and processor 1210, which may execute instructions 1208. The term "processor" is intended to include multi-core processors, which may include two or more independent processors (sometimes referred to as "cores") that may execute instructions simultaneously. While FIG. 12 shows multiple processors 1202, machine 1200 may include one processor with one core, one processor with multiple cores (e.g., a multi-core processor), multiple processors with one core, multiple processors with multiple cores, or any combination thereof.

[0084] Memory 1204 may include a main memory 1212, a static memory 1214, and a storage unit 1216 accessible to processor 1202, such as via bus 1244. Main memory 1204, static memory 1214, and storage unit 1216 store instructions 1208 that embody any one or more of the methodologies or functions described herein. During execution by machine 1200, instructions 1208 may reside, completely or partially, within main memory 1212, within static memory 1214, within a machine-readable medium 1218 in storage unit 1216, within at least one of processors 1202 (e.g., within a processor's cache memory), or any suitable combination thereof.

[0085] I / O components 1242 may include various components that receive input, provide output, generate output, transmit information, exchange information, obtain measurements, and the like. The specific I / O components 1242 included in a particular machine depend on the type of machine. For example, a portable machine such as a mobile phone is likely to include a touch-based input device or other such input mechanism, while a headless server machine is likely to not include such a touch-based input device. It should be understood that I / O components 1242 may include many other components not shown in FIG. 12 . I / O components 1242 are categorized according to functionality solely to simplify the following description, and this categorization is not intended to be limiting in any way. 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., displays such as plasma display panels (PDPs), light-emitting diode (LED) displays, liquid crystal displays (LCDs), projectors, cathode ray tubes (CRTs), etc.), acoustic components (e.g., speakers), tactile components (e.g., vibration motors, resistive mechanisms), other signal generators, etc. Input components 1230 may include alphanumeric input components (e.g., keyboards, touchscreens configured to receive alphanumeric input, optical keyboards, or other alphanumeric input components), pointer-type input components (e.g., mice, touchpads, trackballs, joysticks, motion sensors, and / or other pointing instructions), tactile input components (e.g., physical buttons, touchscreens that provide the position or force of touch or touch gestures, or other tactile input components), audio input components (e.g., microphones), etc.

[0086] In other examples, I / O component 1242 can include a biometric component 1232, a motion component 1234, an environmental component 1236, or a position component 1238, among a wide range of other components. For example, biometric component 1232 can detect facial expressions (e.g., hand expressions, facial expressions, vocal indicators, gestures, or eye tracking), measure biometric signals (e.g., blood pressure, heart rate, body temperature, sweat, or brain waves), authenticate a person (e.g., voice recognition, retinal recognition, facial recognition, fingerprint recognition, or electroencephalogram-based authentication), etc. Motion component 1234 can include an acceleration sensor component (e.g., an accelerometer), a gravity sensor component, a rotation sensor component (e.g., a gyroscope), etc. The environmental components 1236 may include, for example, a lighting sensor component (e.g., a light meter), a temperature sensor component (e.g., one or more thermometers that detect ambient temperature), a humidity sensor component, a pressure sensor component (e.g., a barometer), an acoustic sensor component (e.g., one or more microphones that detect background noise), a proximity sensor component (e.g., an infrared sensor that detects nearby objects), a gas sensor (e.g., a gas detection sensor that detects the concentration of toxic gases for safety purposes or measures pollutants in the air), or other components that may provide indicators, measurements, or signals corresponding to the surrounding physical environment. The location component 1238 may include a location sensor component (e.g., a GPS receiver component), an altitude sensor component (e.g., an altimeter or barometer that can detect air pressure and derive altitude therefrom), a three-dimensional position and orientation sensor component (e.g., a magnetometer), etc.

[0087] Communications may be implemented using a variety of technologies. I / O component 1242 may include a communications component 1240 operable to couple machine 1200 to network 1220 or device 1222 via coupling 1224 and coupling 1226, respectively. For example, communications component 1240 may include a network interface component or another device suitable for interfacing with network 1220. In further examples, communications component 1240 may include a wired communications component, a wireless communications component, a cellular communications component, a near-field communications (NFC) component, a Bluetooth® component (e.g., Bluetooth® Low Energy), a Wi-Fi component, and other communications components providing communications via other modalities. Device 1222 may be another machine or any of a wide range of peripheral devices (e.g., peripheral devices connected via USB).

[0088] Additionally, communications component 1240 may include a component that detects or is operable to detect an identifier. For example, communications 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 codes such as QR Code, Aztec Code, Data Matrix, Dataglyph, MaxiCode, PDF417, Ultra Code, 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 may be derived via communications component 1240, such as location via Internet Protocol (IP) geolocation, location via Wi-Fi signal triangulation, location via detection of NFC beacon signals that may indicate a specific location, etc.

[0089] Executable Instructions and Machine Storage Media Various memories (i.e., memory 1204, main memory 1212, static memory 1214, and / or memory of processor 1202) and / or storage unit 1216 may store one or more sets of instructions and data structures (e.g., software) that embody or are utilized by any one or more of the methodologies or functions described herein. These instructions (e.g., instructions 1208), when executed by processor 1202, cause various operations to be performed to carry out the disclosed examples.

[0090] As used herein, the terms “mechanical storage medium,” “device storage medium,” and “computer storage medium” mean the same thing and can be used interchangeably in this disclosure. These terms refer to a single or multiple storage devices and / or media (e.g., centralized or distributed databases and / or associated caches and servers) that store executable instructions and / or data. Accordingly, these terms should be interpreted to include, without limitation, solid-state memory, as well as optical and magnetic media, and to include memory internal or external to a processor. Specific examples of mechanical storage media, computer storage media, and / or device storage media include, by way of example, semiconductor memory devices, e.g., erasable and programmable read-only memory (EPROM), electrically erasable and programmable read-only memory (EEPROM), FPGAs, non-volatile memory including flash memory devices, magnetic disks such as internal hard disks and removable disks, magneto-optical disks, CD-ROM and DVD-ROM disks. The terms “mechanical 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 covered by the term “signal media” described below.

[0091] Transmission medium 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 network, a wireless network, a Wi-Fi 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 transfer technologies. For example, single-carrier radio transmission technology (1xRTT), Evolution-Data Optimized (EVDO) technology, General Packet Radio Service (GPRS) technology, Enhanced Data rates for GSM Evolution (EDGE) technology, third Generation Partnership Project (3GPP®) 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) standards, as defined by various standards-setting organizations, other long-range protocols, or other data transport technologies.

[0092] The instructions 1208 may be transmitted or received over the network 1220 using a transmission medium via a network interface device (e.g., a network interface component included in the communications component 1240) and utilizing any one of a number of well-known transfer protocols (e.g., Hypertext Transfer Protocol (HTTP)). Similarly, the instructions 1208 may be transmitted or received to the device 1222 using a transmission medium via the coupling 1226 (e.g., a peer-to-peer coupling). The terms “transmission medium” and “signal medium” mean the same thing and may be used interchangeably in this disclosure. The terms “transmission medium” and “signal medium” shall be interpreted to include any intangible medium capable of storing, encoding, or carrying the instructions 1208 for execution by the machine 1200, as well as to include digital or analog communications signals or other intangible media for facilitating the communication of such software. Accordingly, the terms “transmission medium” and “signal medium” shall be interpreted to include all forms of modulated data signals, carrier waves, and the like. 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.

[0093] Computer-readable medium The terms "machine-readable medium," "computer-readable medium," and "device-readable medium" mean the same thing and may be used interchangeably in this disclosure. These terms are defined to include both mechanical storage media and transmission media. Thus, these terms include both storage devices / media and carrier wave / modulated data signals.

[0094] Embodiments of the systems and / or methods may include any combination and permutation of the various system components and various method processes, and one or more example methods and / or processes described herein may be performed asynchronously (e.g., sequentially), simultaneously (e.g., in parallel), or in any other suitable order by and / or using one or more example systems, elements, and / or entities described herein.

[0095] The term "rotor," as used herein when referring to a propulsion element, 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 an articulated or semi-rigid hub (e.g., the blades and the hub can be articulated, flexibly, rigidly, and / or otherwise), and a propeller can refer to a rotary aerodynamic actuator that utilizes a rigid hub (e.g., the blades and the hub can be articulated, flexibly, rigidly, and / or otherwise), as used herein, no such distinction is expressly or implied, and the use of "rotor" can refer to both configurations and any other suitable configurations of articulated or rigid blades and / or blade connections to a central member or hub. Similarly, the use of "propeller" can refer to both configurations and any other suitable configurations of articulated or rigid blades and / or blade connections to a central member or hub. Thus, a tiltrotor aircraft may be referred to as a tiltpropeller aircraft, a tiltprop aircraft, and / or otherwise appropriately called or described.

[0096] The term "board" as used herein in connection with a control board, an inverter board, etc., preferably refers to a circuit board. More preferably, "board" refers to a printed circuit board (PCB) and / or multiple electronic components assembled thereon, which may collectively form a printed circuit board assembly (PCBA). In a first example, the control board is a PCBA. In a second example, the inverter board is a PCBA. However, "board" can additionally or alternatively refer to a single-sided PCB, a double-sided PCB, a multilayer PCB, a rigid PCB, a flexible PCB, and / or have any other suitable meaning.

[0097] The aircraft may include any suitable form of power storage or power storage unit (e.g., batteries, flywheels, ultra-capacitors, batteries, fuel tanks, etc.) that powers one or more actuators (e.g., rotors / propellers, tilt mechanism, blade pitch mechanism, cooling system, etc.). While batteries are the preferred power / fuel source, the system may reasonably be used with any suitable power / fuel source. The aircraft may include auxiliary and / or redundant power sources (e.g., backup batteries, multiple batteries), or may exclude redundant power sources. The aircraft may use batteries having any suitable cell chemistries (e.g., lithium ion, nickel cadmium, etc.) in any suitable electrical architecture or configuration (e.g., multiple packs, bricks, modules, cells, etc., and in any combination of series and / or parallel architectures).

[0098] In a particular example, the system is integrated into an electric tiltrotor aircraft including multiple tiltable rotor assemblies (e.g., six tiltrotor assemblies). The electric tiltrotor aircraft can operate as a fixed-wing aircraft, a rotary-wing aircraft, and in any liminal configuration between fixed-wing and rotary-wing conditions (e.g., one or more of the multiple tiltrotor assemblies are partially rotated). The control system of the electric tiltrotor aircraft in this example can function to command and control the multiple tiltable rotor assemblies in a fixed-wing configuration, a rotary-wing configuration, and / or between the fixed-wing and rotary-wing configurations.

[0099] As used herein, the term "substantially" may mean exactly, approximately, within a predetermined threshold, or within a predetermined tolerance, and / or may have any other suitable meaning.

[0100] Alternatives implement the above-described methods and / or process 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 processing system. The computer-readable medium may include any suitable computer-readable medium, such as RAM, ROM, flash memory, EEPROM, optical device (CD or DVD), hard drive, floppy drive, non-transitory computer-readable medium, or any suitable device. The computer-executable components may include a computing system and / or processing system (e.g., including one or more co-located or distributed, remote or local processors) connected to the non-transitory computer-readable medium, such as a CPU, GPU, TPUS, microprocessor, or ASIC, although the instructions may alternatively or additionally be executed by any suitable dedicated hardware device.

[0101] Embodiments of the systems and / or methods may include any combination and permutation of the various system components and various method processes, and one or more example methods and / or processes described herein may be performed asynchronously (e.g., sequentially), simultaneously (e.g., in parallel), or in any other suitable order by and / or using one or more example systems, elements, and / or entities described herein.

[0102] 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 invention without departing from the scope of the invention, which is defined in the claims that follow.

[0103] Embodiments of the systems and / or methods may include any combination and permutation of the various system components and various method processes, and one or more example methods and / or processes described herein may be performed asynchronously (e.g., sequentially), simultaneously (e.g., in parallel), or in any other suitable order by and / or using one or more example systems, elements, and / or entities described herein.

[0104] 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 invention disclosed in the specification without departing from the scope of the invention as defined in the following claims.

[0105] The following non-limiting examples detail particular aspects of the present subject matter to, among other things, solve the problems and provide the benefits discussed herein. Example 1 is a system for distributing electric energy, comprising a first set of electrically powered devices, a second set of electrically powered devices, a first battery system coupled to one or more of the first set of electrically powered devices, a first fuel cell coupled to one or more of the first set of electrically powered devices, a second battery system coupled to one or more of the second set of electrically powered devices, and a second fuel cell coupled to one or more of the second set of electrically powered devices.

[0106] In Example 2, the subject matter of Example 1 includes a first fuel cell coupled to the first battery system for charging the first battery system. In Example 3, the subject matter of Examples 1-2 includes the first fuel cell being coupled to the second battery system for charging the second battery system.

[0107] In Example 4, the subject matter of Examples 1-3 includes a set of propulsion systems, each of the set of propulsion systems having an electric device from a first set of electric devices coupled to each of the set of propulsion systems and an electric device from a second set of electric devices coupled to each of the set of propulsion systems.

[0108] In Example 5, the subject matter of Example 4 includes one or more of the first set of electrically powered devices coupled to the first fuel cell and one or more of the second set of electrically powered devices coupled to the first fuel cell cumulatively powering all of the propulsion system, such that all of the propulsion system can be powered together by the first fuel cell and the second fuel cell.

[0109] In Example 6, the subject matter of Examples 4-5 includes 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 providing power to all of the propulsion systems, such that all of the propulsion systems may be powered together by the first battery system and the second battery system.

[0110] In Example 7, the subject matter of Examples 5-6 includes 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 providing power to all of the propulsion system, such that all of the propulsion system may be powered together by the first battery system and the second battery system.

[0111] In Example 8, the subject matter of Examples 4-7 includes, during operation, the first fuel cell and the second fuel cell power a set of propulsion systems during steady state operation. In Example 9, the subject matter of Example 8 includes, 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.

[0112] In Example 10, the subject matter of Examples 6-9 includes, during operation, the first battery system and the second battery system power the set of propulsion systems during high power operation of the propulsion systems.

[0113] In Example 11, the subject matter of Example 10 includes, during operation, the first fuel cell and the second fuel cell also power the set of propulsion systems during high power operation of the propulsion systems. In Example 12, the subject matter of Examples 8-11 includes, during operation, the first battery system and the second battery system power the set of propulsion systems during high power operation of the propulsion systems.

[0114] In Example 13, the subject matter of Example 12 includes, during operation, the first fuel cell and the second fuel cell also power the set of propulsion systems during high power operation of the propulsion systems. In Example 14, the subject matter of Examples 9-13 includes the steady state operation being a level flight mode in an aircraft.

[0115] In Example 15, the subject matter of Examples 10-14 includes the high power operation being a vertical flight mode in an aircraft. In Example 16, the subject matter of Examples 10-15 includes the first battery system and the second battery system each comprising a plurality of batteries, and each of the plurality of batteries in each of the first battery system and the second battery system being coupled to a different electric device in the first and second sets of electric devices.

[0116] Example 17 is a method of operating a system for distributing electric energy, the system comprising: a first set of electrically driven devices; a second set of electrically driven devices; a first battery system coupled to one or more of the first set of electrically driven devices; a first fuel cell coupled to one or more of the first set of electrically driven devices; a second battery system coupled to one or more of the second set of electrically driven devices; a second fuel cell coupled to one or more of the second set of electrically driven devices; and a set of propulsion systems, each of which has an electrically driven device from the first set of electrically driven devices coupled thereto and an electrically driven device from the second set of electrically driven devices coupled thereto, the method including 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.

[0117] In Example 18, the subject matter of Example 17 includes powering a set of propulsion systems at least in part using a first fuel cell and a second fuel cell during high power operation. 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.

[0118] In Example 20, the subject matter of Examples 17-19 includes the steady state operation being a horizontal flight mode in an aircraft and the high power operation being a vertical flight mode in an aircraft. Example 21 is a system for distributing electrical energy comprising: 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, in operation, the first battery supplies a first battery voltage to each of one or more of the electrical devices; the second battery supplies a second battery voltage to each of a second subset of the electrical devices; the first DC / DC converter converts the fuel cell voltage from the first fuel cell to 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 to a second battery charging voltage for the second battery.

[0119] 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 in electrical communication with the second fuel cell and the third battery, and a fourth DC / DC converter in electrical communication with 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.

[0120] In Example 23, the subject matter of any one or more of Examples 1-2 optionally includes the first battery voltage being approximately equal to the second battery voltage. 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.

[0121] In Example 25, the subject matter of any one or more of Examples 1-4 optionally includes: the fuel cell voltage is approximately equal to at least one of the first battery voltage and the second battery voltage.

[0122] 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.

[0123] 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 in electrical communication with the second fuel cell and the first battery and the second battery.

[0124] In Example 28, the subject matter of any one or more of Examples 1-7 optionally includes at least one of the electrical devices being an inverter. In Example 29, the subject matter of any one or more of Examples 1-8 optionally includes at least one of the electric devices being an electric motor.

[0125] Example 30 is an aircraft equipped with the system of Example 1. Example 31 is a system for distributing electrical energy, comprising: a first battery in electrical communication with a first electrical device and a second electrical device; a first fuel cell in electrical communication with a third electrical device and a fourth electrical device; and a first DC / DC converter in electrical communication with the first fuel cell and the first battery, wherein, in 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.

[0126] In Example 32, the subject matter of Example 11 optionally includes a second battery in electrical communication with the fifth electrical device and the sixth electrical device, a second fuel cell in electrical communication with the seventh electrical device and the eighth electrical device, and a second DC / DC converter in electrical communication with 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.

[0127] In Example 33, the subject matter of any one or more of Examples 11-12 optionally includes the first battery voltage being approximately equal to the first fuel cell voltage. 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.

[0128] In Example 35, the subject matter of any one or more of Examples 11-14 optionally includes the fuel cell voltage being different from the first battery charging voltage. In Example 36, the subject matter of any one or more of Examples 11-15 optionally includes first, second, third, and fourth electrical devices, 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.

[0129] In Example 37, the subject matter of any one or more of Examples 11-16 optionally includes at least one of the electrical devices being an inverter. In Example 38, the subject matter of any one or more of Examples 11-17 optionally includes at least one of the electric devices being an electric motor.

[0130] Example 39 is an aircraft equipped with the system of Example 11. Example 40 is an aircraft including an electric energy distribution system, the electric energy distribution 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 in operation the first battery supplies a first battery voltage to each of one or more of the electric devices, the second battery supplies a second battery voltage to each of a second subset of the electric devices, the first DC / DC converter converts the fuel cell voltage from the first fuel cell to 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 to a second battery charging voltage for the second battery.

[0131] 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 in electrical communication with the second fuel cell and the third battery, and a fourth DC / DC converter in electrical communication with 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.

[0132] In Example 42, the subject matter of any one or more of Examples 20-21 optionally includes the first battery voltage being approximately equal to the second battery voltage. 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.

[0133] In Example 44, the subject matter of any one or more of Examples 20-23 optionally includes: the fuel cell voltage is approximately equal to at least one of the first battery voltage and the second battery voltage.

[0134] 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.

[0135] 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 in electrical communication with the second fuel cell and the first battery and the second battery.

[0136] In Example 47, the subject matter of any one or more of Examples 20-26 optionally includes at least one of the electrical devices being an inverter. In Example 48, the subject matter of any one or more of Examples 20-27 optionally includes at least one of the electric devices being an electric motor.

[0137] Example 49 is an aircraft including an electric energy distribution system, the electric energy distribution system including: a first battery in electrical communication with a first electric device and a second electric device; a first fuel cell in electrical communication with a third electric device and a fourth electric device; and a first DC / DC converter in electrical communication with the first fuel cell and the first battery, wherein, during operation, the first battery supplies a first battery voltage to each of the first electric device and the second electric device, the first fuel cell supplies a first fuel cell voltage to each of the third electric device and the fourth electric device, and the first DC / DC converter converts the first fuel cell voltage to a first battery charging voltage.

[0138] In Example 50, the subject matter of Example 29 optionally includes a second battery in electrical communication with the fifth electrical device and the sixth electrical device, a second fuel cell in electrical communication with the seventh electrical device and the eighth electrical device, and a second DC / DC converter in electrical communication with 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.

[0139] In Example 51, the subject matter of any one or more of Examples 29-30 optionally includes the first battery voltage being approximately equal to the first fuel cell voltage. In Example 52, the subject matter of any one or more of Examples 29-31 optionally includes wherein the first battery voltage is different from the first fuel cell voltage.

[0140] In Example 53, the subject matter of any one or more of Examples 29-32 optionally includes the fuel cell voltage being different from the first battery charging voltage. In Example 54, the subject matter of any one or more of Examples 29-33 optionally includes first, second, third, and fourth electrical devices, 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.

[0141] In Example 55, the subject matter of any one or more of Examples 29-34 optionally includes at least one of the electrical devices being an inverter. In Example 56, the subject matter of any one or more of Examples 29-35 optionally includes at least one of the electric devices being an electric motor.

[0142] In Example 57, the apparatus or method of any one or any combination of Examples 1-36 can optionally be configured so that all listed elements or options are available or selectable.

[0143] Example 58 is at least one machine-readable medium comprising instructions that, when executed by a processing circuit, cause the processing circuit to perform operations to implement any of Examples 1-57. Example 59 is an apparatus comprising means for implementing any of Examples 1-57. Example 60 is a system for implementing any of Examples 1-57. Example 61 is a method for implementing any of Examples 1-57.

[0144] The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific examples in which the invention may be practiced. Such examples may include elements in addition to those shown or described. However, the inventors also contemplate examples in which only the elements shown or described are provided. Moreover, the inventors also contemplate examples using any combination or permutation of the elements shown or described (or one or more aspects of those elements) with respect to the specific example (or one or more aspects of that example) shown or described herein, or with respect to any other example (or one or more aspects of that example) shown or described herein.

[0145] In the event of inconsistent usage between this specification and a document incorporated by reference, the usage in this specification shall control. The terms "one" or "one" are used herein, as is common in patent documents, to include one or more, regardless of other instances or uses of "at least one" or "one or more." The term "or" is used herein to refer to something inclusive, unless otherwise specified, such that "A or B" includes "A but not B," "B but not A," and "A and B." The terms "including" and "in which" are used herein as the plain-English equivalents of the corresponding terms "comprising" and "wherein." Also, in the following claims, the terms "comprising" and "comprising" are open-ended, i.e., systems, devices, articles, compositions, formulations, or processes that include multiple elements in addition to those recited with such terms in the claims are still considered to be within the scope of the claims. Furthermore, in the following claims, terms such as "first," "second," and "third" are used merely as labels and are not intended to impose numerical requirements on their objects.

[0146] The above description is illustrative and not limiting. For example, the above examples (or one or more aspects thereof) may be used in combination with each other. Other examples may be used by those skilled in the art upon reviewing the above description. The Abstract is provided to comply with 37 CFR Section 1.72(b) to enable 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. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. This should not be construed as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may lie in fewer than all features of a particular disclosed example. Accordingly, the following claims are incorporated into the Detailed Description by way of example or illustration, with each claim standing on its own as a separate example, and it is contemplated that such examples can be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims, along with the full range of equivalents to which such claims are entitled.

Claims

1. 1. A system for distributing electrical energy, comprising: a first set of electromotive devices; a second set of electromotive devices; and a first battery system coupled to one or more of the first set of electrically powered devices; a first fuel cell coupled to one or more of the first set of electrically powered devices; a second battery system coupled to one or more of the second set of electrically powered devices; a second fuel cell coupled to one or more of the second set of electrically powered devices; and A system comprising:

2. 10. The system of claim 1, wherein the first fuel cell is coupled to the first battery system for charging the first battery system.

3. 10. The system of claim 1, wherein the first fuel cell is coupled to the second battery system for charging the second battery system.

4. 10. The system of claim 1, further comprising a set of propulsion systems, each of the set of propulsion systems having one electric-powered device of the first set of electric-powered devices coupled to each of the set of propulsion systems and one electric-powered device of the second set of electric-powered devices coupled to each of the set of propulsion systems.

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

6. 5. The system of 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 provide power to all of the propulsion systems such that all of the propulsion systems may be powered together by the first battery system and the second battery system.

7. 6. The system of claim 5, including 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 providing power to all of the propulsion systems such that all of the propulsion systems may be powered together by the first battery system and the second battery system.

8. The system of 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. 9. The system of 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 of claim 6 , wherein during operation, the first battery system and the second battery system power the set of propulsion systems during high power operation of the propulsion systems.

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

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

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

14. The system of claim 9 , wherein the steady state operation is a level flight mode in an aircraft.

15. The system of claim 10 , wherein the high power operation is a vertical flight mode in an aircraft.

16. 11. The system of claim 10, wherein the first battery system and the second battery system each include a plurality of batteries, and wherein 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 in the first and second sets of electric devices.

17. 1. A method of operating a system for distributing electric energy, the system comprising: a first set of electrically driven devices; a second set of electrically driven devices; a first battery system coupled to one or more of the first set of electrically driven devices; a first fuel cell coupled to one or more of the first set of electrically driven devices; a second battery system coupled to one or more of the second set of electrically driven devices; a second fuel cell coupled to one or more of the second set of electrically driven devices; and a set of propulsion systems, each of the set of propulsion systems having one electrically driven device of the first set of electrically driven devices coupled to each of the set of propulsion systems and one electrically driven device of the second set of electrically driven devices coupled to each of the set of propulsion systems, the method comprising: powering the set of propulsion systems using the first fuel cell and the second fuel cell during steady state operation; powering the set of propulsion systems at least in part using the first battery system and the second battery system during high power operation; A method comprising:

18. The method of claim 17 further comprises: A method 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 of claim 17 further comprises: The method includes recharging the first battery system and the second battery system during steady state operation.

20. 20. The method of claim 17, wherein the steady state operation is a horizontal flight mode in the aircraft and the high power operation is a vertical flight mode in the aircraft.

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