A hybrid electric propulsion system includes a gearbox, an electric motor operably coupled to the gearbox, a battery operably coupled to the electric motor to power the electric motor, and an engine lubrication system. The engine lubrication system includes a tank that holds an engine lubrication fluid. The engine lubrication system includes a pump that is configured to pump the lubrication fluid from the tank toward one or both of the battery and the electric motor through a supply line to maintain one or both of the battery and the electric motor above a threshold temperature.

An electric motor drive system for a propulsion device. The system includes a battery stack having an earth terminal and an end terminal and an electric motor electrically connected to be powered by the battery stack. The motor is configured to be connected to drive the propulsion device, The system also includes: a power converter electrically connected between the battery stack and the electric motor; and a switch between the power converter and the battery stack. The switch is arranged to switch between a first state electrically connecting the end terminal of the battery stack to the power converter to provide a maximum battery voltage to the power converter, and a second state electrically connecting a tap point from one or more intermediate nodes, intermediate the earth terminal and the end terminal, of the battery stack, to provide a voltage less than the maximum battery voltage to the power converter.

An example aircraft includes a parallel propulsion unit, the parallel propulsion unit comprising: a propulsor configured to provide forward propulsion of the aircraft; a gas turbine engine configured to drive the propulsor; an electrical machine configured to generate, for output via one or more electrical busses, electrical energy using mechanical energy derived from the gas turbine engine; and a power sharing module configured to control a ratio of the mechanical energy derived from the gas turbine engine used to drive the propulsor and used to generate electrical energy; and a plurality of series propulsion units, each series propulsion unit comprising a respective propulsor of a plurality of propulsors that are configured to provide forward propulsion of the aircraft and a respective electrical machine each configured to drive a respective propulsor of the plurality of propulsors using electrical energy received from one or more electrical busses.

A method for controlling a hybrid power plant of a vehicle provided with a heat engine and at least one electrical unit comprising an electric machine, an electrical energy source, and a power management unit, the heat engine and the at least one electric machine being mechanically connected to input shafts of a gearbox. After acquiring parameters of the at least one electrical unit, and receiving a mechanical power requirement of the vehicle, a usable electrical power that can be used by the electrical unit and at least one operating setpoint of the electrical unit are determined as a function of the parameters and the mechanical power requirement. Finally, the heat engine and the electrical unit are controlled as a function of the at least one operating setpoint in order to meet the mechanical power requirement.

A drive mechanism for use with an electric motor and a clutch mechanism includes a rotor shaft, a disconnect shaft, a disconnect mechanism, at least one damper element, and a part of a clutch. The rotor shaft and disconnect shaft have a longitudinal axis A. The disconnect shaft transmits torque between the rotor shaft and the clutch mechanism. The disconnect shaft comprises the part of the clutch and a shaft element. The disconnect mechanism is configured to move the disconnect shaft between an engaged position in which the part of the clutch is engaged with the clutch mechanism and a disengaged position in which the part of the clutch is not engaged with the clutch mechanism. The at least one damper element is configured to absorb at least part of any kinetic energy introduced into the disconnect shaft due to movement of the disconnect shaft.

A method of reducing noise includes: driving a first propulsor using one or more of the first electrical motor and the first thermal engine, and driving a second propulsor of the second hybrid power plant using one or more of the second electrical motor and the second thermal engine; receiving a signal indicative of an initial combined noise signature; determining, from the signal, that an initial amplitude variation of a periodically fluctuating amplitude of the initial combined noise signature is greater than an amplitude variation threshold; modulating a thrust produced by the second hybrid power plant, by changing a power output of the second thermal engine or the second electrical motor, to produce a modulated combined noise signature having a modulated amplitude variation less than the initial amplitude variation; and compensating for a difference in thrusts generated by the first hybrid power plant and the second hybrid power plant.

A method of reducing noise includes: driving a first propulsor using one or more of the first electrical motor and the first thermal engine, and driving a second propulsor of the second hybrid power plant using one or more of the second electrical motor and the second thermal engine; receiving a signal indicative of an initial combined noise signature; determining, from the signal, that an initial amplitude variation of a periodically fluctuating amplitude of the initial combined noise signature is greater than an amplitude variation threshold; modulating a thrust produced by the second hybrid power plant, by changing a power output of the second thermal engine or the second electrical motor, to produce a modulated combined noise signature having a modulated amplitude variation less than the initial amplitude variation; and compensating for a difference in thrusts generated by the first hybrid power plant and the second hybrid power plant.

There is provided a hybrid electric aircraft propulsion system and method for operating same. The method comprises providing, to a first electric motor and a second electric motor, alternating current (AC) electric power from a generator, the generator receiving rotational power from a thermal engine, providing, to the first electric motor and the second electric motor, AC electric power from at least one motor inverter, the at least one motor inverter configured to convert DC electric power from a DC power source into AC electric power, and selectively driving the first and second electric motors from the generator, the at least one motor inverter, or a combination thereof, wherein the first electric motor drives a first rotating propulsor and the second electric motor drives a second rotating propulsor.

There is provided a hybrid electric aircraft propulsion system and method for operating same. The method comprises providing, to a first electric motor and a second electric motor, alternating current (AC) electric power from a generator, the generator receiving rotational power from a thermal engine, providing, to the first electric motor and the second electric motor, AC electric power from at least one motor inverter, the at least one motor inverter configured to convert DC electric power from a DC power source into AC electric power, and selectively driving the first and second electric motors from the generator, the at least one motor inverter, or a combination thereof, wherein the first electric motor drives a first rotating propulsor and the second electric motor drives a second rotating propulsor.

A system including a engine having a low spool and a high spool, a first hybrid electric motor connected to the low spool and a second hybrid electric motor connected to the high spool. An auto-throttle controls an amount of power provided to the engine responsive to at least one aircraft parameter. A power splitting algorithm implemented between the auto-throttle and at least one of the first and second hybrid electric motors determines a power split dividing the total engine power into the power produced by burning fuel and electrical power provided to the at least one of the first and second hybrid electric motors responsive to control signals from the auto-throttle.