Patent ID: 11939072
Assignee: AIRBUS HELICOPTERS
Field: Transport (Mechanical engineering)
Classification: CPC B  Y | IPC B

Claim 14:
15. A rotorcraft comprising:
a hybrid power plant provided with one or more engines and with an electric machine;
a rotor driven in rotation with mechanical power from the hybrid power plant;
an electrical energy source electrically powering the electric machine via an electrical network;
a detector device configured to monitor whether the rotorcraft is on the ground;
a control unit configured to monitor whether each of the one or more engines is in the started or on state or in the stopped or off state and to monitor a speed of each of the one or more engines;
a control device configured to monitor whether the electric machine is in the on state or in the off state and to monitor a speed of the electric machine;
the control unit further configured to, in response to the rotorcraft being on the ground and at least one of the one or more engines being in the on state, control each engine in the on state so as to lower the speed of each engine in the on state until the speed of each engine in the on state reaches a predetermined speed referred to as a silent speed, the silent speed being either an idling speed or a reduced speed making it possible to reduce engine noise, the reduced speed of a given engine being a speed that keeps the given engine in the on state; and
the control device further configured to, in response to the speed of each engine in the on state being lowered to reach the silent speed, control the electric machine so that the electric machine delivers mechanical power supplementary to any mechanical power delivered by each engine in the on state for driving the rotor in rotation while complying with a setpoint speed of rotation of the rotor.