A hybrid system for drones and other modes of transport. A combustion engine provides range and/or lifting capacity for drones while electric motors/generators provide both control and maneuverability. One or more combustion engines, in conjunction with one or more electric motors/generators form a propulsion system whereby each is connected to and drives its own driving pinion in one or more planetary gear sets, and provide continuously variable transmission for driving propellers or driveshafts. The combustion engine may be connected directly to one of the planetary gear's driving pinions, or can drive one of the planetary gear's driving pinions. If the propellers are only driven by either a combustion engine, or an electric motor/generator, the other engine/motor will be kept at rest by a braking device for a combustion engine or a braking device for an electric motor/generator.

A hybrid system for drones and other modes of transport. A combustion engine provides range and/or lifting capacity for drones while electric motors/generators provide both control and maneuverability. One or more combustion engines, in conjunction with one or more electric motors/generators form a propulsion system whereby each is connected to and drives its own driving pinion in one or more planetary gear sets, and provide continuously variable transmission for driving propellers or driveshafts. The combustion engine may be connected directly to one of the planetary gear's driving pinions, or can drive one of the planetary gear's driving pinions. If the propellers are only driven by either a combustion engine, or an electric motor/generator, the other engine/motor will be kept at rest by a braking device for a combustion engine or a braking device for an electric motor/generator.

A propulsive assembly including a first and a second gas turbine each having a gas generator and a free power turbine, a main rotor coupled to the free power turbine of a first and a second main coupling, a first and a second reversible electric machine each coupled to the gas generator, by way of a first deactivatable coupling, and each coupled to the main rotor by way of a second deactivatable coupling, the first deactivatable coupling being activated when the electric machines are rotating in a first direction of rotation, and the second deactivatable coupling being activated when the electric machines are rotating in a second direction of rotation opposite to the first direction of rotation.

A turbo-compounded engine includes a piston engine connected to drive a propulsor. An outlet of the piston engine is operable to connect products of combustion from the piston engine to pass over a turbine. The turbine is connected to drive a turbine shaft also connected to drive the propulsor. An outlet of the turbine is connected into an exhaust duct configured to exhaust the products of combustion. The exhaust duct is provided with an exhaust duct outer wall defining an exhaust chamber. A further cooling air outer wall is positioned outwardly of the exhaust duct. Flow dividers are received within an exhaust chamber inward of the exhaust duct outer wall. The exhaust duct outer wall has an inner surface and the flow dividers have an outer surface. Acoustic treatment is provided on both the inner surface of the exhaust duct outer wall and the outer surface of the flow dividers.

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 propulsion system for an aircraft includes a first hybrid power plant and a second hybrid power plant, each including a thermal engine and an electrical motor. Acoustic sensors measure an initial combined noise signature, produced by the propulsion system, including first and second noise signatures respectively generated by the first and second hybrid power plants. A controller receives a signal from the acoustic sensors and determines when an initial amplitude variation of a periodically fluctuating amplitude of the initial combined noise signature is greater than an amplitude variation threshold indicative that the initial combined noise signature generates beats. A thrust produced by the second hybrid power plant is modulated to produce a modulated combined noise signature having a modulated amplitude variation less than the initial amplitude variation. A difference in thrusts generated by the first and second hybrid power plants is compensated for.

A propulsion system for an aircraft includes a first hybrid power plant and a second hybrid power plant, each including a thermal engine and an electrical motor. Acoustic sensors measure an initial combined noise signature, produced by the propulsion system, including first and second noise signatures respectively generated by the first and second hybrid power plants. A controller receives a signal from the acoustic sensors and determines when an initial amplitude variation of a periodically fluctuating amplitude of the initial combined noise signature is greater than an amplitude variation threshold indicative that the initial combined noise signature generates beats. A thrust produced by the second hybrid power plant is modulated to produce a modulated combined noise signature having a modulated amplitude variation less than the initial amplitude variation. A difference in thrusts generated by the first and second hybrid power plants is compensated for.

A method of regenerating an electric power storage unit for an aircraft hybrid electric propulsion (HEP) system is provided. The HEP system includes a thermal engine, an electric motor, an electric power storage unit, a primary gearbox, and a propulsion unit. The electric motor is configured to selectively provide rotational drive to the propulsion unit. The method includes: controlling the electric motor to operate as the generator; controlling the primary gearbox to be in an output disengaged configuration, wherein in the output disengaged configuration the primary gearbox is disengaged from driving the propulsion unit and the primary gearbox is transfers rotational drive produced by the thermal engine to the electric motor; operating the thermal engine to drive the primary gearbox in the output disengaged configuration; and regenerating the electric power storage unit by providing electrical energy produced by the electric motor to the electric power storage unit.

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.

A method of optimizing the noise generated by a hybrid power plant of a rotorcraft in flight, the hybrid power plant driving a main rotor of the rotorcraft in rotation and being provided with at least one engine, with at least one electric machine, and with at least one electrical energy source that electrically powers the electric machine. The method includes a determination step for determining a required power delivered by the hybrid power plant and that is required for the flight phase, and a distribution step for distributing the required power between the at least one engine and the electric machine as a function of a target noise level and of the required power for the flight phase, as well as of a model for the noise generated by the at least one engine as a function of one of its parameters.