Abstract: A method for operating a hybrid-electric propulsion system of an aircraft, the hybrid-electric propulsion system comprising a gas turbine engine having a compressor and an electric machine coupled to the compressor, the method comprising: sensing data indicative of a pressure within the compressor of the gas turbine engine; determining conditions within the compressor are within a threshold of a stall limit for the compressor based at least in part on the sensed data indicative of the pressure within the compressor of the gas turbine engine; and modifying a torque of the compressor using the electric machine in response to determining the conditions within the compressor are within the threshold of the stall limit for the compressor to reduce a risk of compressor stall.

Abstract: An electric machine having an electrically insulative manifold is disclosed. In one example aspect, an electric machine includes a non-electrically conductive manifold. The manifold defines a chamber operable to receive a cooling fluid. The electric machine includes a prime winding in fluid communication with the chamber and one or more secondary windings in electrical communication with the prime winding and in fluid communication with the chamber. Further, the electric machine includes an electric machine terminal extending through the non-electrically conductive manifold and coupled with the prime winding. The electric machine terminal can provide or collect cooling fluid from the chamber of the manifold and can act as the electrical connection point for directing electrical power to or from the windings of the electric machine.

Abstract: A method for operating a hybrid-electric propulsion system of an aircraft is provided. The hybrid-electric propulsion system includes a gas turbine engine having a high pressure system, a low pressure system, and an electric machine coupled to one of the high pressure system or low pressure system. The method includes receiving data indicative of an actual or anticipated in-flight shutdown of the gas turbine engine; and adding power to the gas turbine engine through the electric machine in response to receiving data indicative of the actual or anticipated in-flight shutdown of the gas turbine engine.

Abstract: The present disclosure is directed to an aircraft power generation system including a reverse Brayton cycle system, a gas turbine engine, and a gearbox. The gas turbine engine includes a compressor section, a turbine section, and an engine shaft. The compressor section is arranged in serial flow arrangement with the turbine section. The engine shaft is rotatable with at least a portion of the compressor section and with at least a portion of the turbine section. The reverse Brayton cycle system includes a compressor, a driveshaft, a turbine, and a first heat exchanger. The driveshaft is rotatable with the compressor or the turbine, and the compressor, the first heat exchanger, and the turbine are in serial flow arrangement. The gearbox is configured to receive mechanical energy from the engine shaft and transmit mechanical energy to the reverse Brayton cycle system through the driveshaft.

Abstract: The present disclosure is directed to an aircraft power generation system including a reverse Brayton cycle system, a gas turbine engine, and a gearbox. The gas turbine engine includes a compressor section, a turbine section, and an engine shaft. The compressor section is arranged in serial flow arrangement with the turbine section. The engine shaft is rotatable with at least a portion of the compressor section and with at least a portion of the turbine section. The reverse Brayton cycle system includes a compressor, a driveshaft, a turbine, and a first exchanger. The driveshaft is rotatable with the compressor or the turbine, and the compressor, the first heat exchanger, and the turbine are in serial flow arrangement. The gearbox is configured to receive mechanical energy from the engine shaft and transmit mechanical energy to the reverse Brayton cycle system through the driveshaft.

Abstract: A method for operating a gas turbine engine having a starter-electric generator driven by one of a plurality of shafts of the gas turbine engine is provided. The method includes determining a desired amount of thrust to be produced by the gas turbine engine, as well as a desired amount of electrical power to be generated by the starter-electric generator of the gas turbine engine. The method operates the gas turbine engine to produce the desired amount of thrust, while producing less than the desired amount of electrical power using the starter-electric generator. Producing less than the desired amount of electrical power using the starter-electric generator allows for the desired amount of thrust production, or allows for the desired amount of thrust production more quickly.

Abstract: An electric machine includes a stator assembly including a first stator segment and a second stator segment, the first and second stator segments each including a plurality of laminations extending generally along a circumferential direction, each pair of adjacent laminations of the first and second stator segments defining a gap therebetween. The first and second stator segments are assembled together such that the laminations of the first stator segment are arranged at least partially in the gaps between the laminations of the second stator segment.

Abstract: Aspects of the disclosure generally relate to an aircraft propulsion system for an aircraft. The aircraft propulsion system can include at least an electric power source, an electric machine, a voltage regulator, and at least one propeller. The voltage regulator regulates the electrical power provided to the electric machine from the electrical power source. The electric power source is capable of providing an AC or DC electrical output and can include a combustion engine with a generator or an electrical storage device.

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 method includes receiving a command to operate a power load of a power system at a command output power while operating the power load at a reference output power; operating a gas turbine engine of the power system in a maximum regulator mode to increase a power generation of the gas turbine engine when the command output power is greater than the reference output power or in a minimum regulator mode to decrease the power generation of the gas turbine engine when the command output power is less than the reference output power; and coordinating an electric machine power draw from the gas turbine engine with a change in power generation of the gas turbine engine to maintain a rotational speed parameter of the gas turbine engine substantially constant while operating the gas turbine engine in the maximum regulator mode or in the minimum regulator mode.

Abstract: A multi-energy storage device system includes an electric drive coupled to a load, a DC link coupled to the electric drive, and a bi-directional voltage converter having an output channel coupled to the DC link and an input channel. A first energy storage device (ESD) is coupled to the input channel, and a switch is coupled to the DC link and to a second ESD. A system controller causes the switch to couple the second ESD to the DC link for delivering energy stored in the second ESD to the electric drive. The system controller also causes the voltage converter to convert a voltage of the first ESD to a higher voltage and to deliver the higher voltage to the DC link, wherein the higher voltage is greater than the voltage of the second ESD and causes the switch to decouple the second ESD from the DC link.

Abstract: One example aspect of the present disclosure is directed to a method for operating a gas turbine engine. One example aspect of the present disclosure is directed to a method for operating a gas turbine engine, the gas turbine engine including at least a high pressure spool and a low pressure spool. The method includes causing, by one or more control devices, electrical power to be drawn from the high pressure spool and the low pressure spool into a power distribution system. The method includes determining, by the one or more control devices, a power adjustment event associated with the high pressure spool. The method includes initiating, by the one or more control devices, a power assist operation to redirect electrical power to the high pressure spool based at least in part on the power adjustment event.

Abstract: The present disclosure is directed to turbine engines and systems for active stability control of rotating compression systems utilizing an electric machine operatively coupled thereto. In one exemplary aspect, an electric machine operatively coupled with a compression system, e.g., via a shaft system, is controlled to provide shaft damping for instability fluctuations of the pressurized fluid stream within the compression system. Based on control data indicative of a system state of the compression system, a control parameter of the electric machine is adjusted to control or change an output of the shaft system. Adjusting the shaft system output by adjusting one or more control parameters of the electric machine allows the compression system to dampen instability fluctuations of the fluid stream within the compression system. A method for active stability control of a compression system operatively coupled with an electric machine via a shaft system is also provided.

Abstract: An electric machine is provided which includes a rotor disk extending along a radial direction and having a rotor flange attached to or formed integrally with the rotor disk and extending substantially along the axial direction. A plurality of rotor magnets are mounted on the rotor disk and supported by the rotor flange such that the rotor flange absorbs centrifugal loads exerted on the magnets and enables high speeds of operation.

Abstract: An electric machine is provided which includes a rotor disk extending along a radial direction and a having a rotor magnet embedded within the rotor disk. The electric machine further includes a stator assembly in axial or radial magnetic flux communication with the rotor magnets to generate a torque.

Abstract: A propulsion system for an aircraft includes an electric generator mechanically driven by a combustion engine, with the electric generator configured to generate alternating current electrical power. The propulsion system additionally includes a power bus electrically connected to the electric generator and configured to receive and transmit the alternating current electrical power generated by the electric generator. Additionally, the propulsion system includes, an electric propulsor assembly comprising an electric motor and a propulsor drivingly connected to the electric motor, the electric motor electrically coupled to the power bus for the receiving alternating current electrical power from the power bus.

Abstract: An axial flux electric machine includes a rotor assembly rotatable about an axis, and a stator assembly. The stator assembly includes a stator face defining an air gap along an axial direction with the rotor assembly, the stator assembly further including a yoke, the yoke including a back surface, the back surface defining an inwardly sloped angle with the radial direction greater than two degrees.

Abstract: An apparatus and method for a generator assembly for a drive train such as a rotatable turbine engine assembly. The generator assembly includes at least first and second generators mechanically coupled to the drive train. First and second dampers are operably coupled to the first and second generators, respectively, to selectively damp the first and second generators. Damping the first and second generators can reduce or eliminate both common mode and differential mode torsional oscillations from the generators to the drive train.

Abstract: A method includes receiving a command to operate a power load of a power system at a command output power while operating the power load at a reference output power; operating a gas turbine engine of the power system in a maximum regulator mode to increase a power generation of the gas turbine engine when the command output power is greater than the reference output power or in a minimum regulator mode to decrease the power generation of the gas turbine engine when the command output power is less than the reference output power; and coordinating an electric machine power draw from the gas turbine engine with a change in power generation of the gas turbine engine to maintain a rotational speed parameter of the gas turbine engine substantially constant while operating the gas turbine engine in the maximum regulator mode or in the minimum regulator mode.

Abstract: A multi-energy storage device system includes an electric drive coupled to a load, a DC link coupled to the electric drive, and a bi-directional voltage converter having an output channel coupled to the DC link and an input channel. A first energy storage device (ESD) is coupled to the input channel, and a switch is coupled to the DC link and to a second ESD. A system controller causes the switch to couple the second ESD to the DC link for delivering energy stored in the second ESD to the electric drive. The system controller also causes the voltage converter to convert a voltage of the first ESD to a higher voltage and to deliver the higher voltage to the DC link, wherein the higher voltage is greater than the voltage of the second ESD and causes the switch to decouple the second ESD from the DC link.