A hybrid electric aircraft propulsion system and method of operation are described. The system comprises a thermal engine, a generator coupled to the thermal engine, a first electric propulsor operatively connected to the generator to receive alternating current (AC) electric power therefrom, a second electric propulsor, a generator inverter operatively connected to the generator to convert AC electric power to direct current (DC) electric power, and a first motor inverter operatively connected to the generator inverter and selectively connected to one of the first electric propulsor and the second electric propulsor and configured to receive the DC electric power and provide the first electric propulsor and the second electric propulsor with AC electric power, respectively.

The present disclosure concerns an electrical interconnect system for a vehicle such as an aircraft or marine/submarine vessel. Example embodiments include a vehicle comprising: a first electrical generator; a second electrical generator; an engine arranged to drive the first and second electrical generators; a first electrical distribution system connected to the first electrical generator and arranged to distribute electrical power within the vehicle, the first electrical distribution system comprising a transmission path and a return path; a second electrical distribution system connected to the second electrical generator, the second electrical distribution system comprising a transmission path and a return path; an electric motor configured to provide propulsion for the vehicle and connected to the second electrical generator via the second electrical distribution system, wherein the return path of the second electrical distribution system provides a portion of the return path of the first electrical distribution system.

An aircraft propulsion system comprises first and second propulsors. An epicyclic reduction gearbox is coupled to an input shaft. The reduction gearbox comprises a sun gear coupled to the input shaft, a plurality of planet gears which mesh with the sun gear and are mounted to a planet carrier, and a ring gear which meshes with the plurality of planet gears. The first propulsor is located upstream of the second propulsor The first propulsor is coupled to the sun gear, and the second propulsor is coupled to one of the planet carrier and the ring gear.

An aircraft propulsion system comprises first and second co-axial propulsors, one of the first and second propulsor being positioned forward of the other propulsor. A first electric motor is configured to drive the first propulsor, and a second electric motor is configured to drive the second propulsor. The first electric motor comprising a rotor radially inwardly of the stator, and the second electric motor comprises a rotor radially outwardly of the stator. The stator of the first electric motor is mounted to the stator of the second electric motor.

A system can include a gas turbine and a processing system. The gas turbine can include a compressor coupled to a turbine through a shaft. The processing system can be configured to: automatically transition an operating condition of the system through a plurality of operating states; determine an efficiency of the system at each of a plurality of the operating states; for each of the plurality of operating states: select a future operating state of the system based on the determined efficiency of the current operating state.

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.

A method is provided for maintaining a gas turbine engine installed on an aircraft, the gas turbine engine including an electric machine mounted at least partially inward of a core air flowpath of the gas turbine engine. The method includes removing a rotor mount connecting a rotor of the electric machine to a rotary component of the gas turbine engine; removing a stator mount connecting a stator of the electric machine to a stationary component of the gas turbine engine; and removing in situ the electric machine.

A gas turbine engine according to an exemplary embodiment of this disclosure includes, among other possible things, a fan including a plurality of fan blades rotatable about an axis, a plurality of inlet guide vanes mounted forward of the plurality of fan blades, the plurality of inlet guide vanes selectively rotatable about the axis independent of the plurality of fan blades; and a motor for controlling rotation of the plurality of inlet guide vanes about the axis.

Briefly, example methods, apparatuses, and/or articles of manufacture are disclosed that may be implemented, in whole or in part, to facilitate and/or support one or more operations and/or techniques for a system controller for a series hybrid powertrain, such as employed for propulsion of a hybrid electric aircraft, for example.

Hybrid electric systems and methods therefore are provided. In one exemplary aspect, a hybrid electric system includes an engine, an electric machine operatively coupled thereto and configured to generate electrical power when driven by the engine. One or more electrical loads are electrically connectable with the electric machine. An engine controller of the engine receives load state data indicative of electrical loads that anticipate electrically disconnecting from or electrically connecting to the electric machine at a predetermined time. In this way, the engine controller can anticipate electrical load changes and the engine can be controlled to adjust its torque output in anticipation of the electrical load change. In another exemplary aspect, a hybrid electric system is provided that includes features for nearly instantaneously reacting to load changes on the engine based on load state data received from feed forward inputs of the electrical system of the hybrid electric system.