Propulsion system for an aircraft and method of operation thereof

Abstract

This application discloses a hybrid electric propulsion system including a turbine and an electric motor connected to the turbine. This application also discloses a method for operating the hybrid electric propulsion system, comprising receiving information indicating operability parameters of the turbine; determining, at least in part, that the turbine operates within a predetermined operability range based on the received information indicating the turbine's operability parameters; and operating the hybrid electric propulsion system in a power generation mode in response to determining that the turbine is operating within the predetermined operability range to generate electricity using the electric motor.

Description

Technical Field

[0001] This application generally relates to a hybrid electric aircraft propulsion system for an aircraft, and more specifically, to a method for charging an energy storage unit of the hybrid electric aircraft propulsion system. Background Technology

[0002] A typical aircraft propulsion system includes one or more gas turbine engines. For some propulsion systems, the gas turbine engine generally includes a fan and a core arranged in fluid communication with each other. Additionally, the core of the gas turbine engine generally includes a compressor section, a combustion section, a turbine section, and an exhaust section arranged in a series sequence. In operation, air is supplied from the fan to the inlet of the compressor section, where one or more axial compressors progressively compress the air until it reaches the combustion section. Fuel is mixed with the compressed air and burned within the combustion section to provide combustion gases. The combustion gases are then conveyed from the combustion section to the turbine section. The flow of combustion gases through the turbine section drives the turbine section and is subsequently conveyed through the exhaust section, for example, to the atmosphere.

[0003] Hybrid electric propulsion systems have been proposed, in some cases including an electric fan in addition to at least one gas turbine engine. To increase the efficiency of such hybrid electric propulsion systems, the inventors of this application have recognized that a battery pack can be included to store electricity and provide such electricity to, for example, an electric fan, most needed throughout the flight envelope. However, the inventors of this application further recognize that the battery pack may be susceptible to damage and failure if electricity is not supplied to it in a suitable manner, and additionally, charging the battery pack may depend on one or more operating conditions of, for example, the gas turbine engine, and adversely affect the performance of the gas turbine engine. Therefore, a hybrid electric propulsion system that minimizes the risk of damage to the energy storage unit, energy storage failure, and / or adverse effects on the performance of the gas turbine engine unit while charging the energy storage unit would be suitable. Summary of the Invention

[0004] The aspects and advantages of this application will be set forth in part in the description which follows, or may be apparent from the description, or may be learned by practicing this disclosure.

[0005] In one exemplary aspect of this application, a method is provided for operating a hybrid-electric propulsion system for an aircraft. The hybrid-electric propulsion system includes a turbine and an electric motor connected to the turbine. The method includes: receiving information indicating operability parameters of the turbine; determining, at least in part, that the turbine operates within a predetermined operability range based on the received information indicating the turbine's operability parameters; and operating the hybrid-electric propulsion system in a power generation mode in response to determining that the turbine is operating within the predetermined operability range to generate electricity using the electric motor.

[0006] In some exemplary aspects, receiving information indicating the operability parameters of the turbine includes receiving information indicating the exhaust gas temperature of the turbine, and wherein determining that the turbine operates within a predetermined operability range includes determining that the exhaust gas temperature of the turbine is below an exhaust gas temperature threshold.

[0007] In some exemplary aspects, receiving information indicating turbine operability parameters includes receiving information indicating turbine stall margin, and determining that the turbine operates within a predetermined operability range includes determining that the turbine stall margin is higher than a stall margin threshold.

[0008] In some exemplary aspects, receiving information indicating the operability parameters of the turbine includes receiving information indicating the acceleration demand of the turbine, and wherein determining that the turbine operates within a predetermined operability range includes determining that the acceleration demand of the turbine is below a predetermined threshold.

[0009] In some exemplary aspects, the hybrid electric propulsion system also includes an energy storage unit, wherein operating the hybrid electric propulsion system in a power generation mode to generate electricity includes operating the hybrid electric propulsion system in a charging mode to charge the energy storage unit using the motor in response to determining that the turbine is operating within a predetermined operability range.

[0010] For example, in some exemplary aspects, the method further includes determining that the energy storage unit is in a charging acceptance mode, wherein operating the hybrid electric propulsion system in charging mode includes operating the hybrid electric propulsion system in charging mode in response to determining that the energy storage unit is in a charging acceptance mode and in response to determining that the turbine is operating within a predetermined operability range.

[0011] For example, in some exemplary aspects, determining that an energy storage unit is in charge-accepting mode includes determining that the state of charge of the energy storage unit is below a predetermined maximum level.

[0012] For example, in some exemplary aspects, determining that an energy storage unit is in charge-accepting mode includes receiving information indicating the temperature of the energy storage unit and determining that the temperature of the energy storage unit is within a specified range.

[0013] For example, in some exemplary aspects, the method further includes determining that the turbine is operating in a steady state, and wherein operating the hybrid electric propulsion system in a charging mode to charge the energy storage unit using the motor also includes operating the hybrid electric propulsion system in a charging mode to charge the energy storage unit using the motor, in response to determining that the turbine is operating in a steady state.

[0014] For example, in some exemplary aspects, operating a hybrid electric propulsion system in charging mode to charge an energy storage unit includes using a turbine to rotate a motor and supplying power from the motor to the energy storage unit to charge the energy storage unit.

[0015] For example, in some exemplary aspects, operating a hybrid electric propulsion system in charging mode to charge an energy storage unit using an electric motor also includes regulating the amount of power supplied to the energy storage unit.

[0016] For example, in some exemplary aspects, regulating the amount of power supplied to an energy storage unit includes regulating the amount of power supplied to the energy storage unit based at least in part on the state of charge of the energy storage unit.

[0017] For example, in some exemplary aspects, regulating the amount of power supplied to the energy storage unit includes regulating the amount of power supplied to the energy storage unit based at least in part on information received indicating the operability parameters of the turbine.

[0018] For example, in some exemplary aspects, operating a hybrid electric propulsion system in charging mode to charge an energy storage unit using the electric motor includes providing at least about five kilowatts of power to the energy storage unit.

[0019] In some exemplary aspects, the motor is a first motor, and the hybrid electric propulsion system further includes a second motor and a second thruster connected to the second motor, wherein operating the hybrid electric propulsion system in a power generation mode to generate electricity using the motor includes supplying electricity from the first motor of the hybrid electric propulsion system to the second motor to drive the second thruster and provide propulsion benefits to the aircraft.

[0020] In some exemplary aspects, operating a hybrid electric propulsion system in charging mode involves modifying the operation of the turbine to maintain a substantially constant output power.

[0021] In some exemplary aspects, operating a hybrid electric propulsion system in a power generation mode to generate electricity includes using an electric motor to obtain power from a turbine and transmit such power to a load on the aircraft or at least one of the electric fans of the hybrid electric propulsion system.

[0022] In an exemplary embodiment of this application, a hybrid electric propulsion system is provided. The hybrid electric propulsion system includes: a turbine; an electrical system including a motor connected to the turbine and an energy storage unit electrically connected to the motor; and a controller. The controller is configured to determine, at least in part, that the turbine operates within a predetermined operability range based on received information indicating turbine operability parameters, and is further configured to operate the hybrid electric propulsion system in a charging mode in response to determining that the turbine is operating within the predetermined operability range, so as to charge the energy storage unit using the motor.

[0023] In some exemplary embodiments, the energy storage unit is configured to store at least about fifty kilowatt-hours of electricity.

[0024] In some exemplary embodiments, the operability parameters are one or more of the turbine exhaust gas temperature, turbine stall margin, and turbine acceleration requirements.

[0025] This application discloses a method for operating a hybrid electric propulsion system for an aircraft, the hybrid electric propulsion system including a turbine and an electric motor connected to the turbine, the method including receiving information indicating operability parameters of the turbine; determining, at least in part, that the turbine operates within a predetermined operability range based on the received information indicating the operability parameters of the turbine; and operating the hybrid electric propulsion system in a power generation mode in response to determining that the turbine operates within the predetermined operability range to generate electricity using the electric motor.

[0026] According to the method described in technical solution 1, in this application, receiving information indicating the operability parameters of the turbine includes receiving information indicating the exhaust gas temperature of the turbine, and determining that the turbine operates within the predetermined operability range includes determining that the exhaust gas temperature of the turbine is lower than an exhaust gas temperature threshold.

[0027] According to the method described in technical solution 1, the present application technical solution 3 includes receiving information indicating the operability parameters of the turbine, which includes receiving information indicating the stall margin of the turbine, and determining that the turbine operates within the predetermined operability range includes determining that the stall margin of the turbine is higher than the stall margin threshold.

[0028] According to the method described in technical solution 1, the present application technical solution 4 includes receiving information indicating the operability parameters of the turbine, which includes receiving information indicating the acceleration demand of the turbine, and determining that the turbine operates within the predetermined operability range includes determining that the acceleration demand of the turbine is below a predetermined threshold.

[0029] According to the method described in technical solution 1, the hybrid electric propulsion system further includes an energy storage unit, wherein operating the hybrid electric propulsion system in the power generation mode to generate electricity includes operating the hybrid electric propulsion system in a charging mode to charge the energy storage unit using the motor in response to determining that the turbine is operating within the predetermined operability range.

[0030] According to the method described in technical solution 5, the present application technical solution 6 further includes determining that the energy storage unit is in a charging acceptance mode, wherein determining that the energy storage unit is in the charging acceptance mode includes determining that the state of charge of the energy storage unit is lower than a predetermined maximum level; wherein operating the hybrid electric propulsion system in the charging mode includes operating the hybrid electric propulsion system in the charging mode in response to determining that the energy storage unit is in the charging acceptance mode and in response to determining that the turbine is operating within the predetermined operability range.

[0031] According to the method described in technical solution 6, the method of technical solution 7 of this application includes determining that the energy storage unit is in the charging acceptance mode, which includes receiving information indicating the temperature of the energy storage unit and determining that the temperature of the energy storage unit is within a specified range.

[0032] According to the method described in technical solution 5, the method of operating the hybrid electric propulsion system in the charging mode to charge the energy storage unit using the motor further includes adjusting the amount of power supplied to the energy storage unit.

[0033] According to the method described in technical solution 8, the method of technical solution 9 of this application includes adjusting the amount of power supplied to the energy storage unit, which includes adjusting the amount of power supplied to the energy storage unit based at least in part on the state of charge of the energy storage unit.

[0034] According to the method described in technical solution 10 of this application, operating the hybrid electric propulsion system in the power generation mode to generate electricity using the motor includes operating the hybrid electric propulsion system in the electric transmission mode in response to determining that the turbine is operating within the predetermined operability range to transmit electricity to the load of the hybrid electric propulsion system or the load of the aircraft.

[0035] According to the method described in technical solution 10, the hybrid electric propulsion system is operated in the electric transmission mode to transmit power to the load, which includes adjusting the amount of power supplied to the load.

[0036] According to the method described in technical solution 11, the method of this application 12 includes adjusting the amount of power supplied to the load by at least in part based on the information received indicating the operability parameters of the turbine.

[0037] According to the method described in technical solution 10, the hybrid electric propulsion system operated in the electric transmission mode to transmit power to the load includes providing at least about five kilowatts of power to the load.

[0038] According to the method described in technical solution 10, the present application technical solution 14 further includes determining that the load is in an electrically accepting mode; wherein operating the hybrid electric propulsion system in the electrically transmitting mode includes operating the hybrid electric propulsion system in the electrically transmitting mode in response to determining that the load is in the electrically accepting mode and in response to determining that the turbine is operating within the predetermined operability range.

[0039] According to the method described in technical solution 10, the present application technical solution 15 further includes determining that the turbine operates in a steady state, and wherein operating the hybrid electric propulsion system in the electric transmission mode to charge the energy storage unit using the motor further includes operating the hybrid electric propulsion system in the electric transmission mode in response to determining that the turbine operates in the steady state.

[0040] According to the method described in technical solution 10, the hybrid electric propulsion system operated in the electric transmission mode includes causing the motor to rotate with the turbine.

[0041] According to the method of technical solution 1, the motor is a first motor, and the hybrid electric propulsion system further includes a second motor and a second thruster connected to the second motor. Operating the hybrid electric propulsion system in the power generation mode to generate electricity using the motor includes providing electricity from the first motor of the hybrid electric propulsion system to the second motor to drive the second thruster and provide propulsion benefits to the aircraft.

[0042] According to the method described in technical solution 1, the hybrid electric propulsion system operated in the charging mode includes modifying the operation of the turbine to maintain a substantially constant output power.

[0043] This application discloses a hybrid electric propulsion system, including a turbine; an electrical system including a motor connected to the turbine and an energy storage unit electrically connected to the motor; and a controller configured to determine, at least in part, that the turbine operates within a predetermined operability range based on received information indicating operability parameters of the turbine, and further configured to operate the hybrid electric propulsion system in a charging mode in response to determining that the turbine operates within the predetermined operability range, so as to charge the energy storage unit using the motor.

[0044] This application's technical solution 20 is based on the hybrid electric propulsion system described in technical solution 19, wherein the operability parameter is one or more of the turbine's exhaust gas temperature, the turbine's stall margin, and the turbine's acceleration requirement.

[0045] These and other features, aspects, and advantages of this application will become more readily understood with reference to the following description and the appended claims. The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the application and, together with the description, serve to explain the principles of the application. Attached Figure Description

[0046] This specification sets forth the complete and illustrative disclosure of this application, including its best mode, to those skilled in the art. Reference is made to the accompanying drawings, in which:

[0047] Figure 1 This is a top view of an aircraft according to various exemplary embodiments of this application.

[0048] Figure 2 Is it installed to Figure 1 A schematic cross-sectional view of the gas turbine engine of a demonstrative aircraft.

[0049] Figure 3 This is a schematic cross-sectional view of an electric fan assembly according to an exemplary embodiment of this application.

[0050] Figure 4 This is a schematic diagram of a hybrid electric propulsion system according to an exemplary embodiment of this application.

[0051] Figure 5 This is a schematic diagram of a method for operating a hybrid electric propulsion system of an aircraft according to an exemplary aspect of this application.

[0052] Figure 6 This is a flowchart of a method for operating a hybrid electric propulsion system of an aircraft according to an exemplary aspect of this application.

[0053] Figure 7This is a flowchart of a method for operating a hybrid electric propulsion system of an aircraft according to another exemplary aspect of this application.

[0054] Figure 8 This is a flowchart of a method for operating a hybrid electric propulsion system of an aircraft according to another exemplary aspect of this application.

[0055] Figure 9 It is a computing system based on an example of this application. Detailed Implementation

[0056] Reference will now be made in detail to the present embodiments of this application, one or more of which are illustrated in the accompanying drawings. Numerical and alphanumeric designations are used in the detailed description to refer to features in the drawings. The same or similar designations are used in the drawings and description to refer to the same or similar portions of this application.

[0057] As used in this article, the terms “first,” “second,” and “third” are used interchangeably to distinguish one component from another, and are not intended to indicate the position or importance of individual components.

[0058] The terms "front" and "rear" refer to relative positions within a gas turbine engine or vehicle, and to the normal operating posture of the gas turbine engine or vehicle. For example, relative to a gas turbine engine, "front" refers to a position closer to the engine inlet, while "rear" refers to a position closer to the engine nozzle or exhaust port.

[0059] The terms "upstream" and "downstream" refer to the relative direction of flow along a path. For example, relative to fluid flow, "upstream" refers to the direction in which the fluid flows out, while "downstream" refers to the direction in which the fluid flows in. However, as used in this article, the terms "upstream" and "downstream" can also refer to electric current.

[0060] Unless the context clearly specifies otherwise, the singular form “a” and “the” include the plural reference.

[0061] As used throughout this specification and claims, estimating terms are used to modify any quantity representation that may vary in a permissible manner without causing a change in its associated essential function. Therefore, values ​​modified by words such as “about,” “approximately,” and “substantially” are not limited to the specified exact values. In at least some cases, estimating terms may correspond to the precision of the instrument used to measure the value, or to the precision of the method or machine used to construct or manufacture the component and / or system. For example, estimating terms may refer to a margin of ten percent.

[0062] Scope limitations are combined and / or interchanged herein and throughout the specification and claims, and unless the context or wording otherwise indicates, such scopes are considered to include all subscopes contained therein. For example, all scopes disclosed herein include endpoints, and these endpoints can be independently combined with each other.

[0063] This application generally relates to a method for operating an aircraft's hybrid electric propulsion system in a manner to charge the system's energy storage unit using an electric motor connected to a turbine. The method is generally operable to charge the energy storage unit while minimizing the risk of damage to the energy storage unit; preventing damage, wear, and / or stall of the turbine; and / or simultaneously avoiding any adverse effects on the performance of the turbine and the aircraft.

[0064] In a broader sense, the method may first include determining that the energy storage unit is in a charging acceptance mode. Additionally, the method may include receiving information indicating turbine operability parameters, and determining, at least in part, that the turbine is operating within a predetermined operability range based on the received information indicating turbine operability parameters. In response to making such a determination, the method may operate the hybrid electric propulsion system in charging mode to charge the energy storage unit using the electric motor.

[0065] For example, in some exemplary aspects, the method can ensure that the energy storage unit is not currently overcharged, overheated, etc., when determining whether to charge the energy storage unit (i.e., in charge acceptance mode).

[0066] Furthermore, for example, in some exemplary aspects, the operability parameters may be, or may indicate, parameters above the turbine's exhaust gas temperature, turbine stall margin, turbine acceleration requirements, etc. In such exemplary aspects, the method can ensure that the hybrid electric propulsion system does not draw power from the turbine, for example, when the turbine operates within undesirable exhaust gas temperature limits, when the turbine operates inappropriately close to the stall margin, or when the turbine does not attempt to accelerate. This minimizes the risk of turbine damage / premature wear and further minimizes the risk of turbine stall. Additionally, this ensures that the turbine can generate sufficient thrust for aircraft use. As will be understood from the discussion below, the potentially high power take-off associated with large hybrid propulsion systems, with the power take-off rate from the turbine potentially high enough to affect the turbine's thrust output.

[0067] Referring now to the figures, the same numbers in each figure indicate the same element. Figure 1 A top view of an exemplary aircraft 10, which may be incorporated into various embodiments of this application, is provided. (e.g.) Figure 1As shown, aircraft 10 defines a longitudinal centerline 14 extending through it, a lateral direction L, a forward end 16, and a rear end 18. Furthermore, aircraft 10 includes a fuselage 12 extending longitudinally from the forward end 16 to the rear end 18 and a tail 19 at the rear end of aircraft 10. Additionally, aircraft 10 includes a wing assembly comprising a first port-side wing 20 and a second starboard-side wing 22. The first wing 20 and the second wing 22 each extend outward relative to the longitudinal centerline 14. The first wing 20 and a portion of the fuselage 12 together define a first side 24 of aircraft 10, and the second wing 22 and another portion of the fuselage 12 together define a second side 26 of aircraft 10. For the depicted embodiment, the first side 24 of aircraft 10 is configured as the port side of aircraft 10, and the second side 26 of aircraft 10 is configured as the starboard side of aircraft 10.

[0068] Each of the wings 20, 22 in the depicted exemplary embodiment includes one or more leading edge flaps 28 and one or more trailing edge flaps 30. Aircraft 10 also includes, or in fact, a tail 19 comprising a vertical stabilizer 32 having rudder flaps (not shown) for yaw control and a pair of horizontal stabilizers 34 each having elevator flaps 36 for pitch control. The fuselage 12 also includes an outer surface or skin 38. However, it should be understood that in other exemplary embodiments of this application, aircraft 10 may additionally or alternatively include any other suitable configuration. For example, in other embodiments, aircraft 10 may include any other stabilizer configuration.

[0069] Also for reference Figure 2 and 3 , Figure 1 The demonstrative aircraft 10 also includes a hybrid electric propulsion system 50, which has a first thruster assembly 52 and a second thruster assembly 54. Figure 2 A schematic cross-sectional view of the first thruster assembly 52 is provided, and Figure 3 A schematic cross-sectional view of the second thruster assembly 54 is provided. For the depicted embodiment, the first thruster assembly 52 and the second thruster assembly 54 are each configured in an underwing mounting configuration. However, as will be discussed below, in other exemplary embodiments, one or both of the first thruster assembly 52 and the second thruster assembly 54 may be mounted in any other suitable location.

[0070] More specifically, overall reference Figures 1 to 3 The demonstrative hybrid electric propulsion system 50 generally includes: a first propeller assembly 52, which has a turbine and a main propeller (for... Figure 2In some embodiments, these two are configured together as a gas turbine engine, or in fact as a turbofan engine 100; motor 56 (for Figure 2 The embodiment depicted herein refers to an electric motor / generator), whose drive is connected to a turbine; the second propeller assembly 54 (for Figure 3 In this embodiment, it is configured as follows: an electric thruster assembly 200; an energy storage unit 55 (electrically connectable to a motor 56 and / or the electric thruster assembly 200); a controller 72; and a power bus 58. The electric thruster assembly 200, the energy storage unit 55, and the motor 56 are each electrically connected to each other via one or more wires 60 of the power bus 58. For example, the power bus 58 may include various switches or other power electronics movable to selectively electrically connect various components of the hybrid electric propulsion system 50. Additionally, the power bus 58 may further include power electronics for regulating or converting the power within the hybrid electric propulsion system 50, such as inverters, converters, rectifiers, etc.

[0071] As should be understood, controller 72 can be configured to distribute power among various components of hybrid electric propulsion system 50. For example, controller 72 can be operated in conjunction with power bus 58 (including one or more switches or other power electronics) to supply or draw power from various components such as motor 56, thereby operating hybrid electric propulsion system 50 in various operating modes and performing various functions. This is schematically depicted as wires 60 extending through power bus 58 of controller 72, which will be discussed in more detail below.

[0072] Controller 72 may be a standalone controller dedicated to the hybrid electric propulsion system 50, or alternatively, it may be integrated into one or more of the aircraft 10's main system controller, a separate controller for the demonstrative turbofan engine 100 (e.g., the full authority digital engine control system of the turbofan engine 100, also known as FADEC), etc. For example, controller 72 may be configured as described below. Figure 9 The exemplary computing system 500 described is configured in a substantially similar manner (and can be configured to perform one or more functions of the exemplary method 300 described below).

[0073] Additionally, the energy storage unit 55 may be configured as one or more batteries, such as one or more lithium-ion batteries, or alternatively, may be configured as any other suitable energy storage device. It should be understood that, for the hybrid electric propulsion system 50 described herein, the energy storage unit 55 is configured to store a relatively large amount of electricity. For example, in some exemplary embodiments, the energy storage unit may be configured to store at least about fifty kilowatt-hours of electricity, such as at least about sixty-five kilowatt-hours, such as at least about seventy-five kilowatt-hours, and up to about one thousand kilowatt-hours.

[0074] Now especially referencing Figure 1 and 2 The first propulsion assembly 52 includes a gas turbine engine mounted to or configured to be mounted to the first wing 20 of the aircraft 10. More specifically, for Figure 2 In one embodiment, the gas turbine engine includes a turbine 102 and a propulsion unit, said propulsion unit being a fan (see reference). Figure 2 (Referring to "Fan 104"). Therefore, for Figure 2 In one embodiment, the gas turbine engine is configured as a turbofan engine 100.

[0075] The turbofan engine 100 defines an axial direction A1 (extending parallel to a longitudinal centerline 101 provided for reference purposes) and a radial direction R1. As previously described, the turbofan engine 100 includes a fan 104 and a turbine 102 disposed downstream of the fan 104.

[0076] The depicted exemplary turbine 102 generally comprises a substantially tubular outer casing 106 defining an annular inlet 108. The outer casing 106 encloses, in a series configuration: a compressor section comprising a turbocharger or low-pressure (LP) compressor 110 and a high-pressure (HP) compressor 112; a combustion section 114; a turbine section comprising a first high-pressure (HP) turbine 116 and a second low-pressure (LP) turbine 118; and an exhaust nozzle section 120. The compressor section, combustion section 114, and turbine section together at least partially define a core airflow path 121 through the turbine 102.

[0077] The exemplary turbine 102 of the turbofan engine 100 also includes one or more shafts rotatable together with at least a portion of the turbine section and, in the depicted embodiment, at least a portion of the compressor section. More specifically, in the depicted embodiment, the turbofan engine 100 includes a high-pressure (HP) shaft or rotating shaft 122 that drivesly connects the HP turbine 116 to the HP compressor 112. Additionally, the exemplary turbofan engine 100 includes a low-pressure (LP) shaft or rotating shaft 124 that drivesly connects the LP turbine 118 to the LP compressor 110.

[0078] Furthermore, the depicted exemplary fan 104 is configured as a variable-pitch fan having a plurality of fan blades 128 connected to a disk 130 in a spaced-apart manner. The fan blades 128 extend generally outward from the disk 130 along a radial direction R1. Each fan blade 128 is operably connected to a suitable actuating member 132, with the actuating member configured to collectively vary the pitch of the fan blade 128 relative to the disk 130 about a corresponding pitch axis P1. The fan 104 is mechanically connected to an LP shaft 124 such that the fan 104 is mechanically driven by a second LP turbine 118. More specifically, the fan 104, including the fan blades 128, the disk 130, and the actuating member 132, is mechanically connected to the LP shaft 124 via a power gearbox 134 and can be rotated about a longitudinal axis 101 via the LP shaft 124 spanning the power gearbox 134. The power gearbox 134 includes a plurality of gears for progressively reducing the rotational speed of the LP shaft 124 to a more efficient rotating fan speed. Therefore, the fan 104 is powered by the LP system of the turbine 102 (including the LP turbine 118).

[0079] Still referencing Figure 2 In an exemplary embodiment, the disk 130 is covered by a rotatable front hub 136 having an aerodynamic profile to facilitate airflow through a plurality of fan blades 128. Additionally, the turbofan engine 100 includes an annular fan casing or outer nacelle 138 circumferentially surrounding at least a portion of the fan 104 and / or turbine 102. Therefore, the depicted exemplary turbofan engine 100 may be referred to as a “ducted” turbofan engine. Furthermore, the nacelle 138 is supported relative to the turbine 102 by a plurality of circumferentially spaced outlet guide vanes 140. A downstream section 142 of the nacelle 138 extends above the outer portion of the turbine 102 to define a bypass airflow passage 144 therebetween.

[0080] Still referencing Figure 2 The hybrid electric propulsion system 50 also includes a motor 56, which, in the depicted embodiment, is configured as a motor / generator. In the depicted embodiment, the motor 56 is disposed inwardly from the core airflow path 121 within the turbine 102 of the turbofan engine 100 and is connected / mechanically communicated with a shaft of the turbofan engine 100. More specifically, in the depicted embodiment, the motor is connected to a second LP turbine 118 via an LP shaft 124. The motor 56 may be configured to convert mechanical power of the LP shaft 124 into electrical power (such that the LP shaft 124 drives the motor 56), or alternatively, the motor 56 may be configured to convert the electrical power supplied to it into mechanical power for the LP shaft 124 (such that the motor 56 drives or assists in driving the LP shaft 124).

[0081] However, it should be understood that in other exemplary embodiments, the motor 56 may alternatively be located at any other suitable location within the turbine 102 or elsewhere. For example, in other embodiments, the motor 56 may be mounted coaxially with the LP shaft 124 within the turbine section, or alternatively, it may be offset from the LP shaft 124 and driven via a suitable gear train. Additionally or alternatively, in other exemplary embodiments, the motor 56 may be powered by an HP system, i.e., by the HP turbine 116 via, for example, the HP shaft 122, or by a dual-drive system consisting of both the LP system (e.g., LP shaft 124) and the HP system (e.g., HP shaft 122). In other embodiments, additionally or alternatively, the motor 56 may include multiple motors, for example, one driven to the LP system (e.g., LP shaft 124) and one driven to the HP system (e.g., HP shaft 122). Furthermore, although the motor 56 is described as an electric motor / generator, in other exemplary embodiments, the motor 56 may be configured solely as a generator.

[0082] Still referencing Figure 1 and 2 The turbofan engine 100 also includes a controller 150 and multiple sensors (not shown). The controller 150 may be a full authority digital engine control system, also known as a FADEC. The controller 150 of the turbofan engine 100 can be configured to control the operation of, for example, actuators 132, fuel delivery systems, etc. Additionally, refer to [reference needed]. Figure 1 The controller 150 of the turbofan engine 100 is operably connected to the controller 72 of the hybrid electric propulsion system 50. Furthermore, as should be understood, the controller 72 may also be operably connected via a suitable wired or wireless communication system (described in dashed lines) to one or more of the first thruster assembly 52 (including the controller 150), the motor 56, the second thruster assembly 54, and the energy storage unit 55.

[0083] Furthermore, although not depicted, in some exemplary embodiments, the turbofan engine 100 may also include one or more sensors positioned and configured to sense data indicating one or more operating parameters of the turbofan engine 100. For example, the turbofan engine 100 may include one or more temperature sensors configured to sense the temperature within the core airflow path 121 of the turbine 102. For example, such sensors may be configured to sense the exhaust gas temperature at the outlet of the combustion section 114. Alternatively, the turbofan engine 100 may include one or more pressure sensors to sense data indicating pressure within the core airflow path 121 of the turbine 102, such as data indicating pressure within the combustor in the combustion section 114 of the turbine 102. Furthermore, in yet other exemplary embodiments, the turbofan engine 100 may also include one or more speed sensors configured to sense data indicating the rotational speed of one or more components of the turbofan engine 100, such as data indicating the rotational speed of one or more of the LP shaft 124 or HP shaft 122. Additionally, in some exemplary embodiments, the turbofan engine 100 may include one or more sensors configured to sense data indicating the amount of vibration of various components within the turbofan engine, such as data indicating the amount of vibration of the LP compressor 110, the HP compressor 112, or various support structures.

[0084] In addition, it should be understood that Figure 2 The exemplary turbofan engine 100 depicted herein may have any other suitable configuration in other exemplary embodiments. For example, in other exemplary embodiments, fan 104 may not be a variable-pitch fan, and in other exemplary embodiments, LP shaft 124 may be directly mechanically connected to fan 104 (i.e., turbofan engine 100 may not include gearbox 134). Furthermore, it should be understood that in other exemplary embodiments, turbofan engine 100 may be configured as any other suitable gas turbine engine. For example, in other embodiments, turbofan engine 100 may be configured as a turboprop engine, a ductless turbofan engine, a turbojet engine, a turboshaft engine, etc.

[0085] Now especially refer to Figure 1 and 3 As previously stated, the exemplary hybrid-electric propulsion system 50 also includes a second propeller assembly 54, which, in the depicted embodiment, is mounted to the second wing 22 of the aircraft 10. (See also:...) Figure 3The second thruster assembly 54 is generally configured as an electric thruster assembly 200 comprising a motor 206 and a thruster / fan 204. The electric thruster assembly 200 defines an axial direction A2 and a radial direction R2 extending from a longitudinal centerline axis 202 through which it passes for reference. In the depicted embodiment, the fan 204 is rotatable about the centerline axis 202 via the motor 206.

[0086] Fan 204 includes a plurality of fan blades 208 and a fan shaft 210. The plurality of fan blades 208 are attached to / rotatable with the fan shaft 210 and are generally spaced apart along the circumferential direction (not shown) of the electric propulsion assembly 200. In some exemplary embodiments, the plurality of fan blades 208 may be fixedly attached to the fan shaft 210, or, for example, in the depicted embodiment, the plurality of fan blades 208 may be rotatable relative to the fan shaft 210. For example, each of the plurality of fan blades 208 defines a corresponding pitch axis P2, and in the depicted embodiment, the fan blades are attached to the fan shaft 210 such that the pitch of each of the plurality of fan blades 208 may be uniformly changed, for example, by a pitch-changing mechanism 211. Changing the pitch of the plurality of fan blades 208 can increase the efficiency of the second propulsion assembly 54 and / or allow the second propulsion assembly 54 to achieve a desired thrust distribution. In such exemplary embodiments, fan 204 may be referred to as a variable-pitch fan.

[0087] Furthermore, in the depicted embodiment, the depicted electric propulsion assembly 200 also includes a fan housing or outer nacelle 212 attached to the core 214 of the electric propulsion assembly 200 via one or more support rods or outlet guide vanes 216. In the depicted embodiment, the outer nacelle 212 substantially completely surrounds the fan 204, and in particular surrounds the plurality of fan blades 208. Therefore, in the depicted embodiment, the electric propulsion assembly 200 may be referred to as a ducted electric fan.

[0088] Still especially refer to Figure 3 The fan shaft 210 is mechanically connected to the electric motor 206 within the core 214, such that the electric motor 206 drives the fan 204 via the fan shaft 210. The fan shaft 210 is supported by one or more bearings 218, such as one or more roller bearings, ball bearings, or any other suitable bearings. Alternatively, the electric motor 206 may be an internal rotation motor (i.e., comprising a rotor arranged radially inward from the stator), or alternatively, an external rotation motor (i.e., comprising a stator arranged radially inward from the rotor), or alternatively, an axial flux motor (i.e., wherein the rotor is neither outside nor inside the stator, but is offset from the stator along the motor axis).

[0089] As briefly mentioned above, a power source (e.g., motor 56 or energy storage unit 55) is electrically connected to the electric thruster assembly 200 (i.e., motor 206) to provide power to the electric thruster assembly 200. More specifically, motor 206 is electrically connected to motor 56 and / or energy storage unit 55 via power bus 58, and more specifically via one or more cables or wires 60 extending therethrough.

[0090] However, it should be understood that in other exemplary embodiments, the exemplary hybrid electric propulsion system 50 may have any other suitable configuration, and additionally, may be integrated into the aircraft 10 in any other suitable manner. For example, in other exemplary embodiments, the electric thruster assembly 200 of the hybrid electric propulsion system 50 may be configured as a plurality of electric thruster assemblies 200, and / or the hybrid electric propulsion system 50 may also include a plurality of gas turbine engines (e.g., turbofan engine 100) and electric motors 56.

[0091] Furthermore, in other exemplary embodiments, the electric propulsion assembly 200 and / or the gas turbine engine and the electric motor 56 can be mounted to the aircraft 10 in any other suitable location and in any other suitable manner (including, for example, a tail-mounted configuration). For example, in some exemplary embodiments, the electric propulsion assembly can be configured to draw in boundary layer air and re-excite such boundary layer air, thereby providing a propulsive benefit to the aircraft (the propulsive benefit may be thrust, or it may simply be an increase in the overall net thrust of the aircraft by reducing drag).

[0092] Furthermore, in other exemplary embodiments, the exemplary hybrid electric propulsion system 50 may also have other configurations. For example, in other exemplary embodiments, the hybrid electric propulsion system 50 may not include a "pure" electric thruster assembly. For example, briefly referred to below... Figure 4 A schematic diagram of a hybrid electric propulsion system 50 according to yet another exemplary embodiment of this application is provided. Figure 4 The exemplary hybrid electric propulsion system 50 described herein can be referenced above. Figures 1 to 3 One or more exemplary hybrid electric propulsion systems 50 described are configured in a similar manner.

[0093] For example, Figure 4The exemplary hybrid electric propulsion system 50 generally includes a first thruster assembly 52 and a second thruster assembly 54. The first thruster assembly generally includes a first turbine 102A and a first thruster 104A, and similarly, the second thruster assembly 54 generally includes a second turbine 102B and a second thruster 104B. Each of the first turbine 102A and the second turbine 102B generally includes a low-pressure system having a low-pressure compressor 110 driven to a low-pressure turbine 118 via a low-pressure shaft 124, and a high-pressure system having a high-pressure compressor 112 driven to a high-pressure turbine 116 via a high-pressure shaft 122. Additionally, the first thruster 104A is driven to the low-pressure system of the first turbine 102A, and the second thruster 104B is driven to the low-pressure system of the second turbine 102B. In some exemplary embodiments, the first thruster 104A and the first turbine 102A may be configured as a first turbofan engine, and similarly, the second thruster 104B and the second turbine 102B may be configured as a second turbofan engine (e.g., similar to...). Figure 2 (Exemplary turbofan engine 100). However, another option is that these components can be modified to be configured as parts of a turboprop engine or any other suitable turbine-driven propulsion device. Furthermore, in some exemplary embodiments, the first propulsion assembly 52 can be mounted to the first wing of the aircraft, and the second propulsion assembly 54 can be mounted to the second wing of the aircraft (e.g., similar to...). Figure 1 (Exemplary embodiments). Of course, in other exemplary embodiments, any other suitable configuration may be provided (e.g., both propeller assemblies may be mounted to the same wing, one or both propeller assemblies may be mounted to the tail of the aircraft, etc.).

[0094] also, Figure 4 The hybrid electric propulsion system 50 also includes an electrical system. The electrical system includes a first motor 56A, a second motor 56B, and an energy storage unit 55 electrically connected to the first motor 56A and the second motor 56B. The first motor 56A is further connected to a first turbine 102A. More specifically, in the depicted embodiment, the first motor 56A is connected to the high-voltage system of the first turbine 102A, and even more specifically, to the high-voltage shaft 122 of the first turbine 102A. In this way, the first motor 56A can obtain power from and / or supply power to the high-voltage system of the first turbine 102A.

[0095] Furthermore, it should be understood that, for the depicted embodiment, the second thruster assembly 54 is not configured as a purely electric thruster assembly. Instead, the second thruster assembly 54 is configured as part of a hybrid electric thruster. More specifically, the second motor 56B is connected to the second thruster 104B and further connected to the low-pressure system of the second turbine 102B. In this way, the second motor 56B can obtain power from the low-pressure system of the second turbine 102B and / or supply power to the low-pressure system of the first turbine 102A. More specifically, in some exemplary aspects, the second motor 56B can drive or assist in driving the second thruster 104B.

[0096] For example Figure 4 As depicted, the exemplary hybrid electric propulsion system 50 also includes a controller 72 and a power bus 58. The first motor 56A, the second motor 56B, and the energy storage unit 55 are each electrically connected to each other via one or more wires 60 of the power bus 58. For example, the power bus 58 may include various switches or other power electronics that are movable to selectively electrically connect various components of the hybrid electric propulsion system 50 and, as needed, convert or regulate the power transmitted through it.

[0097] Furthermore, it should be understood that in other exemplary embodiments, the exemplary hybrid electric propulsion system 50 may have other suitable configurations. For example, although Figure 4 An exemplary embodiment includes a first motor 56A connected to a high-voltage system of a first turbine 102A and a second motor 56B connected to a low-voltage system of a second turbine 102B. However, in other exemplary embodiments, each of the motors 56A and 56B may be connected to either the low-voltage system or the high-voltage system. Alternatively, in other exemplary embodiments, the electrical system may further include additional motors connected to the low-voltage system of the first turbine 102A and / or additional motors connected to the high-voltage system of the second turbine 102B.

[0098] As stated above, this application generally provides a method for operating a hybrid electric propulsion system for an aircraft, and more specifically, a method for charging the energy storage unit of the hybrid electric propulsion system for an aircraft. For example, reference is now made to... Figure 5 The process 300 provides an exemplary aspect of this application.

[0099] As depicted, process 300 first includes determining at 302 whether the energy storage unit of the hybrid electric propulsion system is in a charging acceptance mode. In some exemplary aspects, determining whether the energy storage unit is in a charging acceptance mode at 302 may include determining that the charging level or state of charge is below a predetermined threshold (e.g., a maximum threshold). Alternatively, in some exemplary aspects, determining whether the energy storage unit is in a charging acceptance mode at 302 may include determining whether the energy storage unit is in a fault state. For example, determining whether the energy storage unit is in a fault state may include monitoring the stability of the energy storage unit, such as determining whether the temperature of the energy storage unit is within a specified range. This specified range may be the safe operating range of the energy storage unit. Charging or attempting to charge outside this range may potentially damage the energy storage unit. However, it is worth noting that determining whether the energy storage unit is in a fault state may include monitoring any other stability-related parameters of the energy storage unit. Therefore, for example, at 302, the logic may determine that the energy storage unit is in charge acceptance mode in response to determining that the state of charge is below a predetermined threshold and / or in response to determining that the energy storage unit is not in a fault state (e.g., the temperature of the energy storage unit is within a specified range).

[0100] Additionally, the logic described in process 300 includes determining at 304 whether the turbine's operating parameters are within a predetermined operability range. In some exemplary aspects, operability parameters may be one or more of the following: turbine exhaust gas temperature, turbine stall margin, turbine acceleration demand, turbine power level, turbine exhaust air demand (e.g., the amount of air discharged from the turbine compressor section downstream of the low-pressure compressor and upstream of the high-pressure compressor). Therefore, in response to determining, for example, that the turbine exhaust gas temperature is below a predetermined threshold, the turbine stall margin is greater than a predetermined threshold, the turbine acceleration demand is below a predetermined threshold, the turbine power level is above a minimum threshold (e.g., above idling), and / or the exhaust air demand is below a certain threshold (e.g., the engine is operating below a certain power level, where, for example, an aircraft draws a large amount of exhaust air from the turbine), the logic can determine at 304 that the turbine is within a predetermined operability range. One or more sensors within the turbine may be used to determine these operating parameter values. In addition, these operating parameter values, within the corresponding predetermined operability range, indicate that power can be obtained in the case of relatively low risk of damaging / prematurely wearing down the turbine, without limiting the turbine's ability to provide increased thrust when needed, and also in the case of relatively low risk of turbine stall.

[0101] As depicted, the logic described in process 300 may operate the hybrid electric propulsion system in electric standby mode at 306 in response to determining at 302 that the energy storage unit is not operating in charge-accepting mode and / or at 304 that the turbine's operability parameters are not within a predetermined operability range. In standby mode, the energy storage unit may, for example, supply power to the motor or elsewhere, or may simply remain idling.

[0102] However, in contrast, in response to determining at 302 that the energy storage unit is in a charging acceptance mode and at 304 that the turbine's operability parameters are within a predetermined operability range, the logic can operate the hybrid electric propulsion system in a charging mode at 308. When operating the hybrid electric propulsion system in charging mode at 308, the hybrid electric propulsion system can operate the motor connected to the turbine as a generator by causing the motor connected to the turbine to rotate with the turbine, and provide such electricity to the energy storage unit to charge the energy storage unit.

[0103] It is worth noting that, for Figure 5 As an exemplary aspect described herein, the logic depicted in process 300 also includes modifying the turbine operation at 310 to maintain a substantially constant output power when operating the hybrid electric propulsion system in charging mode at 308. Thus, for example, in some exemplary aspects, when operating the hybrid electric propulsion system in charging mode, the described logic may increase the fuel flow to the turbine to account for the effective drag on the turbine caused by obtaining power through the electric motor.

[0104] Next, the logic loops back to ensure at 302 that the energy storage unit remains in charge-accepting mode and at 304 that the turbine's operability parameters remain within a predetermined operability range, so that at 308 the hybrid electric propulsion system can continue to operate in charge mode or stop operating at 308 if conditions have changed.

[0105] It should be understood that, although the preceding (and following) text is relative to... Figure 5 The logic presented may appear to relate to a configuration where a single turbine charges a single energy storage unit, but aspects of this application may also relate to using one or more turbines (and associated motors) to charge one or more energy storage units. For example, if a first energy storage unit is not in a charging accepting mode, power can be diverted to a second energy storage unit (assuming the second energy storage unit is in a charging accepting mode). Similarly, if the operability parameters of the first turbine are not within a predetermined operability parameter range, a second turbine (and associated motor) can provide power to the one or more energy storage units (assuming the operability parameters of the second turbine are within the predetermined operability parameter range).

[0106] For reference Figure 6 A method 400 for operating a hybrid electric propulsion system for an aircraft is provided according to an exemplary aspect of this application. Figure 6 Method 400 can be similar to the above reference. Figure 5 The exemplary logic described above, and may also be referenced in conjunction with the above text. Figures 1 to 4 One or more exemplary hybrid electric propulsion systems are described and operated. Thus, for example, the exemplary hybrid electric propulsion system may generally include a turbine, an electric motor connected to the turbine, and an energy storage unit.

[0107] Method 400 generally includes determining at (402) that the energy storage unit is in a charging acceptance mode. Determining at (402) that the energy storage unit is in a charging acceptance mode may generally include ensuring that the energy storage unit is in a state of accepting charging. For example, for the exemplary aspect depicted, determining at 402 that the energy storage unit is in a charging acceptance mode generally includes determining at (404) that the state of charge or charging level of the energy storage unit is below a predetermined level. The predetermined level may be a predetermined maximum level, for example, below the maximum charging level of the energy storage unit. Alternatively or additionally, the predetermined level may be a predetermined minimum level for performing certain operations such as starting or restarting the turbine.

[0108] Similarly, for the exemplary aspect described, determining at (402) that the energy storage unit is in charge-accepting mode also includes receiving information indicating the temperature of the energy storage unit at (406) and determining at (408) that the temperature of the energy storage unit is within a specified range. The specified range may be a temperature range within which the risk of damage to the energy storage unit caused by charging it is minimal. For example, some energy storage units may be susceptible to damage when charging or attempting to charge when the temperature of the energy storage unit is below a lower temperature threshold, and additionally, they may be susceptible to damage when charging or attempting to charge when the temperature of the energy storage unit is above a higher temperature threshold (e.g., thermal runaway events).

[0109] Furthermore, although not depicted, it should be understood that, in other exemplary aspects, determining that the energy storage unit is in a charging acceptance mode at (402) may also include any other suitable determination to ensure that the energy storage unit is in a state suitable for accepting charging. For example, in at least some exemplary aspects, determining that the energy storage unit is in a charging acceptance mode at (402) may also include determining that the energy storage unit does not have a charging-related fault indication.

[0110] Still referencing Figure 6In an exemplary aspect of the method 400 described herein, method 400 further includes receiving information at (410) indicating turbine operability parameters and at (412) determining, at least in part, that the turbine operates within a predetermined operability range based on the information received at (410) indicating turbine operability parameters. Furthermore, as will be discussed in more detail below, Figure 6 The exemplary aspects of the method 400 described herein include operating the hybrid electric propulsion system in a power generation mode in response to determining that the turbine is operating within a predetermined operability range to generate electricity using the electric motor, and more specifically includes operating the hybrid electric propulsion system in a charging mode at (414) in response to determining that the energy storage unit is in a charging acceptance mode at (402) and in response to determining that the turbine is operating within a predetermined operability range at (412) to charge the energy storage unit using the electric motor.

[0111] For example, here's a simple reference. Figure 7 The flowchart provides an exemplary aspect of the depicted method 400, in which, in at least some exemplary aspects, receiving information indicating turbine operability parameters at (410) includes receiving information indicating turbine exhaust gas temperature at (416). Furthermore, in such exemplary aspects, determining at (412) that the turbine is operating within a predetermined operability range includes determining at (418) that the turbine exhaust gas temperature is below an exhaust gas temperature threshold. In this way, method 400 ensures that the turbine is not placed outside of safe or desired operating conditions for charging the energy storage unit. This reduces the risk of turbine damage or premature wear.

[0112] Alternatively or concurrently, in at least some exemplary aspects, receiving information indicating turbine operability parameters at (410) includes receiving information indicating turbine stall margin at (420). Furthermore, in such exemplary aspects, determining at (412) that the turbine is operating within a predetermined operability range includes determining at (422) that the turbine stall margin is above a stall margin threshold. In this way, method 400 ensures that the turbine is not in a state that increases the risk of stall in order to charge the energy storage unit of the hybrid electric propulsion system. The information indicating stall margin received at (420) may be, for example, one or more temperatures within the turbine, pressure within the turbine, rotational speeds of various components within the turbine, turbine stability degradation coefficients, etc.

[0113] Alternatively or additionally, in at least some exemplary aspects, receiving information indicating turbine operability parameters at (410) includes receiving information indicating turbine acceleration demand at (424). In such exemplary aspects, determining at (412) that the turbine is operating within a predetermined operability range includes determining at (426) that the turbine acceleration demand is below an acceleration demand threshold. In this way, method 400 can be performed without compromising the hybrid electric propulsion system and, in particular, the turbine's ability to provide increased thrust during operation. For example, when operating the hybrid electric propulsion system to perform a phased climb, the method can identify a relatively high acceleration demand of the turbine and prevent or stop the hybrid electric propulsion system from operating in charging mode, thereby allowing the turbine to accelerate as desired.

[0114] Alternatively or additionally, although not depicted, in other exemplary aspects, receiving information indicating turbine operability parameters at (410) may include receiving information indicating any other suitable operability parameters. For example, receiving information indicating turbine operability parameters at (410) may include receiving information indicating the turbine's power level, the turbine's exhaust air demand (e.g., the amount of air discharged from the turbine compressor section downstream of the low-pressure compressor and upstream of the high-pressure compressor), etc. Therefore, it should be understood that, in some exemplary aspects, determining at (412) that the turbine is operating within a predetermined operability range may also include determining that the turbine's power level is above a minimum threshold (e.g., above idling), the exhaust air demand is below a certain threshold (e.g., the engine is operating below a certain power level, where, for example, the aircraft draws a large amount of exhaust air from the turbine), etc.

[0115] In addition, return especially for reference Figure 6 In an exemplary aspect, method 400 includes additional safeguards to ensure the hybrid electric propulsion system operates as desired before operating in charging mode. More specifically, Figure 6The exemplary method 400 also includes determining at (428) that the turbine is operating under steady-state operating conditions. For example, in at least some exemplary aspects, determining that the turbine is operating in a steady-state state at (428) may include monitoring one or more temperatures and / or pressures within the turbine over a period of time to determine that such temperatures and / or pressures remain substantially constant, monitoring inputs from crew members (e.g., throttling), and / or data indicating such inputs, etc. Alternatively or additionally, in some exemplary aspects, determining that the turbine is operating in a steady-state state at (428) may include monitoring the corrected or physical rotational speed of one or more rotating components within the turbine and determining that such rotational speed remains substantially constant. Furthermore, as depicted, in such exemplary aspects, operating the hybrid electric propulsion system in a charging mode at (414) to charge the energy storage unit using the motor also includes, at (430), operating the hybrid electric propulsion system in a charging mode to charge the energy storage unit using the motor in response to determining that the turbine is operating in a steady-state state at (428).

[0116] However, it should be understood that Figure 6 The exemplary aspects of method 400 depicted herein are by way of example only, and in other exemplary aspects, method 400 may not include one or more of the exemplary checks depicted. For example, in some exemplary aspects, method 400 may wish to charge one or more energy storage units when the turbine is not operating in a steady state.

[0117] Still referring to the charging mode operation of the hybrid electric propulsion system at (414), for Figure 6 An exemplary aspect of method 400 described herein, operating the hybrid electric propulsion system in charging mode at (414) to charge the energy storage unit using the motor, also includes rotating the motor with the turbine at (432) and supplying power from the motor to the energy storage unit at (434) to charge the energy storage unit. It is noteworthy that, although not depicted, in at least some exemplary aspects, supplying power from the motor to the energy storage unit at (434) may also include supplying power via one or more power electronic devices to regulate or convert the power. For example, the power may be converted from alternating current (“AC”) to direct current (“DC”) via power electronic devices. Therefore, in such exemplary aspects, the power electronic devices may include rectifiers or other power electronic devices.

[0118] In addition, for Figure 6 In an exemplary aspect of the method 400 described herein, operating the hybrid electric propulsion system in charging mode at (414) to charge the energy storage unit using the motor also includes adjusting the amount of power supplied to the energy storage unit at (436). For example, in Figure 6The exemplary aspect described herein includes adjusting the amount of power supplied to the energy storage unit at (436) which may include adjusting the amount of power supplied to the energy storage unit at (438) based at least in part on received information indicating turbine operability parameters. For example, if the actual exhaust gas temperature of the turbine is significantly lower than an exhaust gas temperature threshold, then a relatively high amount of power may be supplied from the motor to the energy storage unit to charge the energy storage unit. In contrast, if the actual exhaust gas temperature of the turbine is only slightly lower than the exhaust gas temperature threshold, then a relatively low amount of power may be supplied from the motor to the energy storage unit to charge the energy storage unit. Similar logic applies when the operability parameters refer to turbine stall margin or turbine acceleration requirements.

[0119] Alternatively or alternatively, as depicted by the dashed lines, in at least some exemplary aspects, adjusting the amount of power supplied to the energy storage unit at (436) may include adjusting the amount of power supplied to the energy storage unit at (440) based at least in part on determining that the energy storage unit is in a charging accepting mode at (402), and more specifically, at least in part on the determined state of charge of the energy storage unit. For example, if the state of charge of the energy storage unit is much lower than the desired state of charge, a relatively high amount of power may be supplied from the motor to the energy storage unit to charge it. In contrast, if the state of charge of the energy storage unit is only slightly lower than the desired state of charge, a relatively low amount of power may be supplied from the motor to the energy storage unit to charge it. Alternatively or alternatively, adjusting the amount of power supplied to the energy storage unit at (440) based at least in part on determining that the energy storage unit is in a charging accepting mode may include adjusting the amount of power supplied to the energy storage unit based at least in part on the temperature of the energy storage unit. For example, the amount of electrical energy supplied to the energy storage unit may decrease as the temperature approaches a relevant temperature limit.

[0120] Furthermore, as discussed above with reference to exemplary embodiments, it should be understood that the energy storage unit is a relatively large energy storage unit and the motor is a relatively high-power motor. For example, the energy storage unit may be configured to store at least about fifty kilowatt-hours of electricity. Additionally, in some exemplary aspects, operating the hybrid electric propulsion system in charging mode at (414) may include providing at least about five kilowatts of power.

[0121] Still referencing Figure 6In exemplary aspects of method 400 as described above, the hybrid electric propulsion system may, in at least some exemplary aspects, also include a second motor connected to a second thruster. For example, the second thruster may be configured as part of an electric thruster assembly (e.g., an electric fan), or alternatively, may be configured in conjunction with a second turbine as, for example, a second turbofan engine. In one or more of these embodiments, method 400 may also include (as depicted in dashed lines) a second motor at (442) supplying electricity from at least one of the motor and the energy storage unit to the hybrid electric propulsion system, such that the second motor can at least partially drive the second thruster and provide propulsion benefits (e.g., thrust) to the aircraft. It is noteworthy that, although depicted as separate elements, in some exemplary aspects, operating the hybrid electric propulsion system in a power generation mode in response to determining that the turbine is operating within a predetermined range of operability to generate electricity using the motor may include supplying electricity from at least one of the motor and the energy storage unit to the hybrid electric propulsion system via a second motor.

[0122] Alternatively or in other exemplary aspects of the described method 400, method 400 may also include supplying electricity from an energy storage unit to an electric motor to drive or assist in driving a turbine, a propeller, or both.

[0123] According to one or more of the exemplary aspects above, the operation of the hybrid electric propulsion system can allow the charging of the energy storage unit without impairing the operation of other components of the hybrid electric propulsion system, such as the turbine of the hybrid electric propulsion system, and reduce the risk of damage or premature wear of the turbine.

[0124] Furthermore, while method 400 (and logic 300) is generally aimed at determining when to use the motor to charge the energy storage unit, it should be understood that method 400 (and logic 300) can be further applied in a more general way to determine when to use the motor to obtain power from the turbine to, for example, provide electricity to the load of an aircraft or the load of a hybrid electric propulsion system.

[0125] For example, here is a brief reference. Figure 8 A flowchart of method 400 according to another exemplary aspect of this application is provided. As depicted, Figure 8 The exemplary aspects of the method 400 described herein generally include receiving information indicating turbine operability parameters at (410) and determining, at (412) based at least in part on the received information indicating turbine operability parameters, that the turbine operates within a predetermined operability range. Additionally, Figure 8An exemplary aspect of the method 400 described herein also includes operating the hybrid electric propulsion system in a power generation mode at (415) in response to determining that the turbine is operating within a predetermined operability range, so as to generate electricity using the electric motor. In some exemplary aspects, operating the hybrid electric propulsion system in a power generation mode at (415) may include operating the hybrid electric propulsion system in a charging mode to charge the energy storage unit using the electric motor (see, for example...). Figure 6 (414)). However, another option is that method 400 can be used to provide power to any other suitable load of an aircraft or a hybrid electric propulsion system. As used herein, the term "load" refers to any component capable of receiving electrical power. For example, the load may be an aircraft electrical system configured to power one or more features or components of an aircraft, an electric fan of a hybrid electric propulsion system, an energy storage unit of a hybrid electric propulsion system, etc.

[0126] Therefore, for the exemplary aspect described, operating the hybrid electric propulsion system in power generation mode at (415) includes operating the hybrid electric propulsion system in power transmission mode at (444) in response to determining at (412) that the turbine is operating within a predetermined range of operability, to transmit power to the load of the hybrid electric propulsion system or the load of the aircraft.

[0127] It is worth noting that, in other aspects, Figure 8 More general aspects of the method 400 described herein may be similar to other exemplary aspects of the method 400 described above. For example, as described, for Figure 8 An exemplary aspect of method 400, operating the hybrid electric propulsion system in electric transmission mode at (444) includes adjusting the amount of power supplied to the load at (446). More specifically, adjusting the amount of power supplied to the load at (446) includes adjusting the amount of power supplied to the load at (448) based at least in part on information received at (410) indicating the operability parameters of the turbine. Furthermore, for the exemplary aspect depicted, operating the hybrid electric propulsion system in electric transmission mode at (444) includes supplying at least about five kilowatts of power to the load at (450) and causing the motor to rotate with the turbine at (451).

[0128] In addition, for Figure 8In an exemplary aspect of method 400, the method includes determining at (452) that the load is in an electrically accepting mode. (For example, when the load is an energy storage unit, the electrically accepting mode may be a charging accepting mode, but in other respects, the electrically accepting mode may generally refer to a component mode in which components may need to accept power, can safely accept power, etc.) In such an exemplary aspect, operating the hybrid electric propulsion system in an electrically transmitting mode at (444) includes operating the hybrid electric propulsion system in an electrically transmitting mode at (454) in response to determining at (452) that the load is in an electrically accepting mode and in response to determining at (412) that the turbine is operating within a predetermined operability range.

[0129] In addition, for Figure 8 An exemplary aspect of method 400 is that the method further includes determining at (456) that the turbine is operating in a steady-state state. In such an exemplary aspect, operating the hybrid electric propulsion system in an electric transmission mode at (444) further includes operating the hybrid electric propulsion system in an electric transmission mode at (458) in response to determining at (456) that the turbine is operating in a steady-state state.

[0130] Therefore, it should be understood that, in such exemplary cases, method 400 may more broadly include operating the hybrid electric propulsion system in a power generation mode to generate electricity using the electric motor in response to determining that the turbine is operating within a predetermined range of operability (as opposed to operating the hybrid electric propulsion system in a charging mode), and further enabling the generation of such electricity to be supplied to any suitable load of the aircraft or propulsion system.

[0131] For reference Figure 9 This application describes an example computing system 500 according to an exemplary embodiment of the present application. The computing system 500 may, for example, serve as a controller 72 of a hybrid electric propulsion system 50. The computing system 500 may include one or more computing devices 510. The computing device 510 may include one or more processors 510A and one or more memory devices 510B. The one or more processors 510A may include any suitable processing means, such as a microprocessor, microcontroller, integrated circuit, logic device, and / or other suitable processing means. The one or more memory devices 510B may include one or more computer-readable media, including but not limited to non-transitory computer-readable media, RAM, ROM, hard disk drives, flash drives, and / or other memory devices.

[0132] One or more memory devices 510B may store information accessible by one or more processors 510A, including computer-readable instructions 510C executable by one or more processors 510A. Instructions 510C may be any set of instructions that, when executed by one or more processors 510A, cause one or more processors 510A to perform an operation. In some embodiments, instructions 510C may be executed by one or more processors 510A to cause one or more processors 510A to perform an operation, such as any of the operations and functions configured for use by the computing system 500 and / or computing device 510, operations of a hybrid-electric propulsion system for operating an aircraft as described herein (e.g., method 300), and / or any other operations or functions of one or more computing devices 510. Therefore, it should be understood that, in some exemplary aspects, the above references... Figures 5 to 8 The exemplary methods 300 and 400 described may be computer-implemented methods, causing one or more computing devices to be used to perform one or more of the corresponding steps described above. Instructions 510C may be software written in any suitable programming language or may be implemented in hardware. Additionally and / or alternatively, instructions 510C may be executed on processor 510A in logically and / or practically separate threads. Memory device 510B may additionally store data 510D accessible by processor 510A. For example, data 510D may include data indicating the operating mode of the hybrid electric propulsion system, the amount of electrical energy stored in the energy storage unit, the rotational speed of one or more shafts or rotating shafts of the turbine, and / or one or more loads on one or more shafts or rotating shafts of the turbine.

[0133] The computing device 510 may also include a network interface 510E for communicating, for example, with other components of the system 500 (e.g., via a network). The network interface 510E may include any suitable components for connecting to one or more network interfaces, including, for example, a transmitter, receiver, port, controller, antenna, and / or other suitable components. One or more external display devices (not depicted) may be configured to receive one or more commands from the computing device 510.

[0134] The techniques discussed herein refer to computer-based systems and actions taken by computer-based systems, as well as information sent to and from computer-based systems. Those skilled in the art will recognize that the inherent flexibility of computer-based systems allows for a wide range of possible configurations, combinations, and divisions of tasks and functionalities between and within components. For example, the processes discussed herein can be implemented using a single computing device or multiple computing devices working in combination. Databases, memories, instructions, and applications can be implemented on a single system or distributed across multiple systems. Distributed components can operate sequentially or in parallel.

[0135] While specific features of various embodiments may be shown in some figures but not in others, this is merely for convenience. In accordance with the principles of this application, any feature of a particular figure may be referenced and / or claimed in connection with any feature of any other figure.

[0136] This written description uses examples to disclose the invention, including the optimal mode, and also enables those skilled in the art to implement the invention, including making and using any apparatus or system and performing any incorporated methods. The patentable scope of the invention is defined by the claims and may include other examples that may occur to those skilled in the art. Such other examples are deemed to be within the scope of the claims if they include structural elements that are not different from the literal language of the claims, or if they include equivalent structural elements that are not substantially different from the literal language of the claims.

Claims

1. A method for operating a hybrid electric propulsion system for an aircraft, the hybrid electric propulsion system comprising a turbine and an electric motor connected to the turbine, the method comprising: Receive information indicating the operability parameters of the turbine; The turbine is determined to operate within a predetermined operability range based at least in part on the received information indicating the operability parameters of the turbine; as well as In response to determining that the turbine is operating within the predetermined operability range, the system operates in a power generation mode to generate electricity using the motor. When the exhaust gas temperature of the turbine is lower than a first threshold value for exhaust gas temperature by a certain amount, a first amount of electricity is supplied from the motor to the energy storage unit. When the exhaust gas temperature of the turbine is lower than a second threshold value for exhaust gas temperature by a certain amount, a second amount of electricity is supplied from the motor to the energy storage unit. The first amount is greater than the second amount, and the first quantity is greater than the second quantity.

2. The method according to claim 1, further comprising: In response to determining that the operability parameters of the turbine are outside the predetermined operability range, the turbine is operated in an electric standby mode.

3. The method of claim 2, wherein, Operating in the electric standby mode includes supplying power to the motor.

4. The method according to any of the preceding claims, further comprising: In response to determining that the turbine is operating within the predetermined operability range, it operates in an electric transmission mode to transmit electricity to the load of the hybrid electric propulsion system or the load of the aircraft.

5. The method according to claim 4, further comprising: Adjust the amount of electricity supplied to the hybrid electric propulsion system or the load of the aircraft.

6. The method of any preceding claim, wherein, Operating in the power generation mode to generate electricity includes operating in a charging mode in response to determining that the turbine is operating within the predetermined operability range, so as to charge the energy storage unit using the motor.

7. The method of claim 6, wherein, Operating in the charging mode to charge the energy storage unit using the motor also includes adjusting the amount of power supplied to the energy storage unit.

8. The method according to any one of claims 6 or 7, wherein the method further comprises: Determining that the energy storage unit is in a charging acceptance mode includes determining that the state of charge of the energy storage unit is below a predetermined maximum level.

9. The method of any one of claims 6-8, wherein, Operating in the charging mode includes operating in the charging mode in response to determining that the energy storage unit is in a charging acceptance mode.

10. The method of claim 8, wherein, Determining that the energy storage unit is in the charging acceptance mode includes receiving information indicating the temperature of the energy storage unit and determining that the temperature of the energy storage unit is within a specified range.

11. A hybrid electric propulsion system, comprising: Turbine; An electrical system comprising a motor connected to the turbine and an energy storage unit electrically connected to the motor; as well as A controller configured to determine, at least in part, that the turbine operates within a predetermined operability range based on received information indicating operability parameters of the turbine, and further configured to operate the hybrid electric propulsion system in a power generation mode to generate electricity using the motor in response to determining that the turbine operates within the predetermined operability range; When the exhaust gas temperature of the turbine is lower than a first threshold value for exhaust gas temperature by a certain amount, a first amount of electricity is supplied from the motor to the energy storage unit. When the exhaust gas temperature of the turbine is lower than a second threshold value for exhaust gas temperature by a certain amount, a second amount of electricity is supplied from the motor to the energy storage unit. The first amount is greater than the second amount, and the first quantity is greater than the second quantity.

12. The hybrid electric propulsion system of claim 11, wherein, The controller is further configured to operate in an electric standby mode in response to determining that the operability parameters of the turbine are outside the predetermined operability range.

13. The hybrid electric propulsion system of claim 12, wherein, When the hybrid electric propulsion system operates in the electric standby mode, power is supplied to the motor.

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