The invention relates to a method for driving an air vehicle using a multilevel converter with at least two converter modules. A first operating voltage is applied to at least one of the converter modules in a first operating state, and a second operating voltage which is lower than the first operating voltage is applied to the converter module in a second operating state. The air vehicle is designed to carry out such a method and comprises an electric drive which has at least one multilevel converter with at least two converter modules, each of which is designed and connected so as to be supplied with a first operating voltage in a first operating state and with a second operating voltage which is lower than the first operating voltage in a second operating state. Advantageously, the air vehicle is an airplane, in particular a hybrid electric airplane.

The invention relates to a method for driving an air vehicle using a multilevel converter with at least two converter modules. A first operating voltage is applied to at least one of the converter modules in a first operating state, and a second operating voltage which is lower than the first operating voltage is applied to the converter module in a second operating state. The air vehicle is designed to carry out such a method and comprises an electric drive which has at least one multilevel converter with at least two converter modules, each of which is designed and connected so as to be supplied with a first operating voltage in a first operating state and with a second operating voltage which is lower than the first operating voltage in a second operating state. Advantageously, the air vehicle is an airplane, in particular a hybrid electric airplane.

A method of synchronizing a cross-compound generator system on one or more turning gears during startup includes determining, via a notch monitor controller, first and second angular velocities, respectively, of a first and a second rotor. The method also includes simultaneously exciting, via the notch monitor controller, the first and second rotors to attain electromechanical coupling therebetween. The method further includes determining, via the notch monitor controller, a value of a time at which a calibration value of an offset is a constant value, where the offset is representative of a phase alignment of the first rotor relative to the second rotor, and where the offset is indicative of a successful electromechanical coupling therebetween. The method also includes disengaging the one or more turning gears from the cross-compound generator system.

A method of synchronizing a cross-compound generator system on one or more turning gears during startup includes determining, via a notch monitor controller, first and second angular velocities, respectively, of a first and a second rotor. The method also includes simultaneously exciting, via the notch monitor controller, the first and second rotors to attain electromechanical coupling therebetween. The method further includes determining, via the notch monitor controller, a value of a time at which a calibration value of an offset is a constant value, where the offset is representative of a phase alignment of the first rotor relative to the second rotor, and where the offset is indicative of a successful electromechanical coupling therebetween. The method also includes disengaging the one or more turning gears from the cross-compound generator system.

Exhaust gases from an engine, input to turbo-compounder, drive a bladed turbine rotor therein, which drives a multi-phase AC generator, the output of which is used to electrically drive a multi-phase induction motor, the rotor of which is mechanically coupled to the engine, so as to provide for recovering power to the engine. The multi-phase AC generator may be coupled to the engine either by closure of a contactor, engagement of an electrically-controlled clutch, or by control of either a solid-state switching or control system or an AC excitation signal, when the frequency (f.sub.GENERATOR) of the multi-phase AC generator meets or exceeds that (f.sub.MOTOR) of the multi-phase induction motor.

Exhaust gases from an engine, input to turbo-compounder, drive a bladed turbine rotor therein, which drives a multi-phase AC generator, the output of which is used to electrically drive a multi-phase induction motor, the rotor of which is mechanically coupled to the engine, so as to provide for recovering power to the engine. The multi-phase AC generator may be coupled to the engine either by closure of a contactor, engagement of an electrically-controlled clutch, or by control of either a solid-state switching or control system or an AC excitation signal, when the frequency (f.sub.GENERATOR) of the multi-phase AC generator meets or exceeds that (f.sub.MOTOR) of the multi-phase induction motor.

Exhaust gases from an engine, input to turbo-compounder, drive a bladed turbine rotor therein, which drives a multi-phase AC generator, the output of which is used to electrically drive a multi-phase induction motor, the rotor of which is mechanically coupled to the engine, so as to provide for recovering power to the engine. The multi-phase AC generator may be coupled to the engine either by closure of a contactor, engagement of an electrically-controlled clutch, or by control of either a solid-state switching or control system or an AC excitation signal, when the frequency (f.sub.GENERATOR) of the multi-phase AC generator meets or exceeds that (f.sub.MOTOR) of the multi-phase induction motor.

Exhaust gases from an engine, input to turbo-compounder, drive a bladed turbine rotor therein, which drives a multi-phase AC generator, the output of which is used to electrically drive a multi-phase induction motor, the rotor of which is mechanically coupled to the engine, so as to provide for recovering power to the engine. The multi-phase AC generator may be coupled to the engine either by closure of a contactor, engagement of an electrically-controlled clutch, or by control of either a solid-state switching or control system or an AC excitation signal, when the frequency (f.sub.GENERATOR) of the multi-phase AC generator meets or exceeds that (f.sub.MOTOR) of the multi-phase induction motor.

The invention relates to an injected laser (200) comprising an optical amplifying medium (2) arranged inside a triggered laser cavity (3), the optical amplifying medium (2) having a spectral amplifying band. According to the invention, the injected laser (200) includes an optical phase-modulation device (20), arranged between the injection source (11) and the laser cavity (3), the optical phase-modulation device (20) being configured to periodically modulate as a function of time a phase of the monochromatic continuous laser radiation (10) at a modulation frequency (fm) equal to a natural integer multiple of the free spectral range (FSR) of the laser cavity (3), so that the phase-modulated injection source generates a polychromatic injection radiation (120).

The invention relates to an injected laser (200) comprising an optical amplifying medium (2) arranged inside a triggered laser cavity (3), the optical amplifying medium (2) having a spectral amplifying band. According to the invention, the injected laser (200) includes an optical phase-modulation device (20), arranged between the injection source (11) and the laser cavity (3), the optical phase-modulation device (20) being configured to periodically modulate as a function of time a phase of the monochromatic continuous laser radiation (10) at a modulation frequency (fm) equal to a natural integer multiple of the free spectral range (FSR) of the laser cavity (3), so that the phase-modulated injection source generates a polychromatic injection radiation (120).