Abstract: A method of mitigating thermal rotor bow in a rotor assembly of a turbine engine may include performing a plurality of motoring cycles. The plurality of motoring cycles may include receiving feedback on a temperature within a turbine engine in a post-shutdown state, actuating a starter motor when the temperature is greater than a predetermined threshold, operating the starter motor for a motoring time to exhaust some residual heat from the turbine engine, and shutting down the starter motor after the motoring time.

Abstract: Hybrid electric propulsion systems includes a combustion engine and an electric motor. The hybrid electric propulsion systems may include or utilize a non-transitory computer-readable medium comprising computer-executable instructions, which when executed by a processor associated with the hybrid electric propulsion system, cause the processor to perform a method that includes determining an occurrence of a thrust asymmetry in the hybrid electric propulsion system, and controlling the electric motor to decrease an efficiency of the electric motor for a transient time period sufficient to reduce a torque output of the combustion engine to match an electrical load on the combustion engine.

Abstract: A method of operating a turbine engine that includes shutting down the turbine engine such that a rotational speed of the turbine engine decreases, and actuating a starter motor of the turbine engine at one of as the rotational speed of the turbine engine decreases or at a preset time after the turbine engine receives a full stop command such that residual heat is exhausted from the turbine engine.

Abstract: A hybrid-electric propulsion system includes a propulsor, a turbomachine, and an electrical system having an electric machine coupled to the turbomachine. A method for operating the propulsion system includes operating, by one or more computing devices, the turbomachine to rotate the propulsor and generate thrust for the aircraft; receiving, by the one or more computing devices, data indicative of an un-commanded loss of the thrust generated from the turbomachine rotating the propulsor; and providing, by the one or more computing devices, electrical power to the electric machine to add power to the turbomachine, the propulsor, or both in response to receiving the data indicative of the un-commanded loss of thrust.

Abstract: A system for controlling power distribution is provided. The system includes an engine operably coupled to an electric machine and a first power electronics device configured in a power control mode to modulate power extracted by the electric machine. A second power electronics device is configured in a voltage control mode and is operably coupled to a load device to modulate power received by the load device from the first power electronics device. Modulating power received by the load device is based at least on an operating limit corresponding to the load device, a voltage of the electric bus, or both. A computing system is operably coupled to the engine and the first power electronics device, wherein the computing system is configured to send control commands to the engine and the first power electronics device.

Abstract: A system for controlling a motor includes a controller module comprising a controller portion, a regulator portion and an integrator portion. The regulator portion includes a set of regulator modules communicatively coupled in a sequence. Each regulator module configured to receive a respective input signal, indicative of a target or selected value, from the controller portion or the immediately preceding regulator module in the sequence, determine a respective selectable value; select one of the respective selectable value and the value indicated by the received input signal; and provide the selected value as an output signal to the next regulator module in the sequence or the integrator module. The integrator module is configured to receive the output signal from the last regulator module in the sequence, calculate a final demand value based on the received signal, and provide an output signal indicative of the final demand value.

Abstract: An aircraft that includes a hybrid-electric propulsion system is provided. In one aspect, the hybrid-electric propulsion system includes at least one propulsor that includes a gas turbine engine and an electric machine mechanically coupled with a spool of the gas turbine engine. When idle operation is commanded, electrical power is provided to the electric machine to cause the electric machine to apply torque to the spool and fuel provided to the engine can be reduced. Thus, the electric machine is controlled to provide a power assist to maintain the engine at the commanded idle speed whilst reducing fuel consumption.

Abstract: A system for controlling a motor includes a controller module comprising a controller portion, a regulator portion and an integrator portion. The regulator portion includes a set of regulator modules communicatively coupled in a sequence. Each regulator module configured to receive a respective input signal, indicative of a target or selected value, from the controller portion or the immediately preceding regulator module in the sequence, determine a respective selectable value; select one of the respective selectable value and the value indicated by the received input signal; and provide the selected value as an output signal to the next regulator module in the sequence or the integrator module. The integrator module is configured to receive the output signal from the last regulator module in the sequence, calculate a final demand value based on the received signal, and provide an output signal indicative of the final demand value.

Abstract: Turbine engine systems equipped with a fuel deoxygenation system and turboelectric power system are provided. In one aspect, a turbine engine system includes a turboelectric power system having an electric generator operatively coupled with a gas turbine engine. A fuel line provides fuel to the gas turbine engine. A fuel deoxygenation system is positioned along the fuel line for reducing an amount of oxygen in the fuel. A main fuel pump is positioned downstream of the fuel deoxygenation system along the fuel line. An electric motor drives the main fuel pump. An electric generator of a turboelectric power system is operatively coupled with the gas turbine engine and generates electrical power. The electrical power is provided to the electric motor and the fuel deoxygenation system. Heat is recovered from the turboelectric power system and the electric motor and is imparted to fuel provided to the gas turbine engine.

Abstract: A hybrid-electric propulsion system for an aircraft is provided herein that can include a propulsor and a turbomachine comprising a high pressure turbine drivingly coupled to a high pressure compressor through a high pressure spool. An auxiliary power unit can be operably coupled with a starter motor. An electrical system can comprise a first electric machine coupled to the turbomachine. The first electric machine can be separate from the starter motor. A controller can be configured to provide electrical power from an electric power source to the first electric machine to drive the first electric machine to start, or assist with starting, the turbomachine.

Abstract: Hybrid electric propulsion systems includes a combustion engine and an electric motor. The hybrid electric propulsion systems may include or utilize a non-transitory computer-readable medium comprising computer-executable instructions, which when executed by a processor associated with the hybrid electric propulsion system, cause the processor to perform a method that includes determining an occurrence of a thrust asymmetry in the hybrid electric propulsion system, and controlling the electric motor to decrease an efficiency of the electric motor for a transient time period sufficient to reduce a torque output of the combustion engine to match an electrical load on the combustion engine.

Abstract: Hybrid electric propulsion systems and methods therefore are provided. More particularly, the present disclosure is directed to control systems for hybrid electric propulsion systems for aerial vehicles that are configured for rapidly and automatically taking action in response to rapid electrical load changes on a torque source, such as an engine. Methods for operating hybrid electric propulsion systems for aerial vehicles are also provided.

Abstract: A gas turbine engine and method of starting, the gas turbine engine having a rotor comprising at least a shaft mounted compressor and turbine, with a casing surrounding the rotor. The method comprises an acceleration phase, a bowed-rotor cooling phase, during the acceleration, and a combustion phase. The bowed-rotor cooling phase comprises a time where the rotational speed of the rotor is maintained below a bowed-rotor threshold speed until a non-bowed condition is satisfied, wherein the air forced through the gas turbine engine cools the rotor. The combustion phase occurs after the bowed-rotor cooling phase and upon reaching the combustion speed, wherein fuel is supplied to the gas turbine engine is turned on.

Abstract: A method of mitigating thermal rotor bow in a rotor assembly of a turbine engine may include performing a plurality of motoring cycles. The plurality of motoring cycles may include receiving feedback on a temperature within a turbine engine in a post-shutdown state, actuating a starter motor when the temperature is greater than a predetermined threshold, operating the starter motor for a motoring time to exhaust some residual heat from the turbine engine, and shutting down the starter motor after the motoring time.

Abstract: A hybrid-electric propulsion system for an aircraft includes a turbomachine, the turbomachine including a first spool and a second spool. A method for operating the hybrid electric propulsion system includes operating, by one or more computing devices, the turbomachine such that the first spool mechanically drives a prime propulsor of the hybrid-electric propulsion system; and modifying, by the one or more computing devices, a speed relationship parameter defined between the first spool and second spool by providing electrical power to, or drawing electrical power from, an electric machine mechanically coupled to the first spool, the second spool, or both.

Abstract: A hybrid-electric propulsion system includes a turbomachine and an electric machine coupled to the turbomachine. A method for operating the hybrid-electric propulsion system includes receiving information indicative of an operability parameter of the turbomachine; determining the turbomachine is operating within a predetermined operability range based at least in part of the received information indicative of the operability parameter of the turbomachine; and operating the hybrid electric propulsion system in an electric generation mode to generate electric power with the electric machine in response to determining the turbomachine is operating within the predetermined operability range.

Abstract: A method for operating a permanent magnet electric machine of an engine includes determining a fault condition of the permanent magnet electric machine; and reducing a magnetism of one or more permanent magnets of the permanent magnet electric machine by increasing a temperature of the one or more permanent magnets in response to determining the fault condition of the permanent magnet electric machine.

Abstract: A hybrid-electric propulsion system includes a turbomachine and an electrical system, the electrical system including an electric machine coupled to the turbomachine. A method for operating the propulsion system includes receiving, by one or more computing devices, a command to accelerate the turbomachine to provide a desired thrust output; receiving, by the one or more computing devices, data indicative of a temperature parameter approaching or exceeding an upper threshold; and providing, by the one or more computing devices, electrical power to the electric machine to add power to the turbomachine to provide, or assist with providing, the desired thrust output in response to receiving the command to accelerate the turbomachine and receiving the data indicative of the temperature parameter approaching or exceeding the upper threshold.

Abstract: A hybrid-electric propulsion system for an aircraft is provided herein that can include a propulsor and a turbomachine comprising a high pressure turbine drivingly coupled to a high pressure compressor through a high pressure spool. An auxiliary power unit can be operably coupled with a starter motor. An electrical system can comprise a first electric machine coupled to the turbomachine. The first electric machine can be separate from the starter motor. A controller can be configured to provide electrical power from an electric power source to the first electric machine to drive the first electric machine to start, or assist with starting, the turbomachine.

Abstract: A hybrid-electric propulsion system includes a propulsor, a turbomachine, and an electrical system, the electrical system including an electric machine coupled to the turbomachine. A method for operating the propulsion system includes operating, by one or more computing devices, the turbomachine in a steady-state flight operating condition, the turbomachine rotating the propulsor when operated in the steady-state flight operating condition; receiving, by the one or more computing devices, a command to accelerate the turbomachine while operating the turbomachine in the steady-state flight operating condition; and providing, by the one or more computing devices, electrical power to the electric machine to add power to the turbomachine, the propulsor, or both in response to the received command to accelerate the turbomachine.