A method of controlling a hybrid power unit includes receiving a target total thrust value that is converted into a target speed for a propeller. The target speed is transmitted to a motor speed controller. A sensor value for a current speed for the propeller is received at the motor speed controller. The motor speed controller generates a signal to a primary electric motor to selectively output torque to a rotor and regeneratively brake the rotor according to the target speed. A module current set point based at least in part on a state of charge of a battery is received. A throttle set point is determined based in part on the target speed and the module current set point. A throttle set point of an internal-combustion engine of the hybrid power unit is adjusted based at least in part on the target speed and the module current set point.

An aircraft includes a closed wing, a fuselage at least partially disposed within a perimeter of the closed wing, and one or more spokes coupling the closed wing to the fuselage. A source of electric power is disposed within or attached to the closed wing, fuselage or one or more spokes. A plurality of electric motors are disposed within or attached to the one or more spokes in a distributed configuration. Each electric motor is connected to the source of electric power. A propeller is operably connected to each of the electric motors and proximate to a leading edge of the one or more spokes. One or more processors are communicably coupled to the plurality of electric motors. A longitudinal axis of the fuselage is substantially vertical in the vertical takeoff and landing and the stationary flight, and substantially in a direction of flight in the forward flight.

An electrical power system includes: an electrical machine to output AC; DC electrical network; power electronics converter connected between the AC output of the electrical machine and the DC electrical network and having a phase leg having first and second branches respectively having first and second bi-directional MOSFETs; and controller controlling switching of the first and second bi-directional MOSFETs of each phase leg of the converter so that current is commutated between the phase leg first and second branches rectifying the AC input to DC to supply the DC electrical network with DC electrical power. The controller is responsive to a determination to the effect that there is a fault in the DC electrical network, to control the switching of each phase leg first and second bi-directional MOSFETs to switch the converter into a crow-bar configuration in which electrical machine current does not flow to the DC network.

A hybrid-electric aircraft system is provided and includes first and second hybrid-electric engines, first and second ducting systems fluidly communicative with each other and with the first and second hybrid-electric engines, respectively, and a control system. The control system is operably coupled to each of the first and second hybrid-electric engines and to each of the first and second ducting systems. The control system is configured to run the first hybrid-electric engine normally, to run the second hybrid-electric engine in a lower power mode and to control each of the first and second ducting systems to direct bleed air from the first hybrid-electric engine to the second hybrid-electric engine.

The present invention includes a distributed propulsion system for a craft that comprises a frame, a plurality of hydraulic or electric motors disposed within or attached to the frame in a distributed configuration; a propeller operably connected to each of the hydraulic or electric motors, a source of hydraulic or electric power disposed within or attached to the frame and coupled to each of the disposed within or attached to the frame, wherein the source of hydraulic or electric power provides sufficient energy density for the craft to attain and maintain operations of the craft, a controller coupled to each of the hydraulic or electric motors, and one or more processors communicably coupled to each controller that control an operation and speed of the plurality of hydraulic or electric motors.

Hybrid aircraft power plants are provided together with associated systems and methods for operating such hybrid aircraft power plants. A hybrid aircraft power plant includes a thermal engine, an electric motor and one or more controllers operatively connected to the thermal engine and to the electric motor. The thermal engine and the electric motor are drivingly connected to an air mover of an aircraft via a combining gear train. The one or more controllers are configured to govern an actual output torque of the electric motor to reduce an error between a target operating speed for the air mover and an actual operating speed of the air mover, and govern an output of the thermal engine to reduce an error between a target output torque for the electric motor and the actual output torque of the electric motor.

A method and system for operating a hybrid propulsion system, includes controllably providing a first power to a first bus and a first inverter, electrically coupling a first motor with a second inverter by way of a second bus, operably converting, by the second inverter, the first power received by the first inverter to a starting power adapted for starting the first motor, and increasing, by the second inverter, the starting power to match the first power received.

Turbine engine systems include a core assembly having a compressor section, a burner section, and a turbine section arranged along a shaft, with a core flow path through the turbine engine such that exhaust from the burner section passes through the turbine section and exits through a nozzle. A core condenser is arranged downstream of the turbine section and upstream of the nozzle and configured to condense water from the core flow path. A fuel cell is operably connected to the core assembly. A fuel source is configured to supply a fuel to each of the burner section for combustion and the fuel cell for reaction to generate electricity. At least one electric motor is operably coupled to the core assembly and configured to impart power to a portion of the core assembly and the fuel cell is configured to supply electrical power to the at least one electric motor.

The present invention relates to an aircraft provided with a rotary airfoil, a power plant and an assistance system having an electric motor. The power plant comprises a power transmission box and at least one heat engine. The aircraft includes at least one accessory which is set in motion by a secondary output shaft of the power transmission box. The assistance system is provided with a mechanical connection module having a connection shaft which is connected to the secondary output shaft. A first connection member is connected to said at least one accessory and is connected by a first mechanical link internal to the connection shaft, a second connection member being connected to the electric motor and connected by a second mechanical link internal to the connection shaft.

A hybrid aircraft architecture is disclosed that uses an electric motor-generator-propeller propulsion system for takeoff, landings, and low speed flying, and wave engines for cruise-condition flying and flying at high speeds. The propeller of the electric motor-generator-propeller propulsion system can be located at the nose or aft end (tail) of the aircraft. The wave engines can be located at the aft end of the fuselage, or under or integrated into the wing structures. The wave engines can be deployed in pairs and the wave engines of the pair may be cross-connected and operated in an anti-phase mode to reduce the noise and vibration that would exist if each wave engine is operated independently.