Method for controlling a gas turbine engine

A gas turbine engine, comprising a spool comprising a compressor, a turbine and a drive shaft, the turbine being able to drive the compressor via the drive shaft, an electric motor able to drive the drive shaft in rotation, and a control module configured to:

• estimate a temperature gradient between a first portion of the spool and a second portion of the spool;
• compare the estimated temperature gradient with a predefined temperature gradient threshold;
• if the temperature gradient is less than the predefined temperature gradient threshold, drive the drive shaft in rotation at a rotational speed varying over time according to a first profile of rotational speed variation;
• and
• if the temperature gradient is greater than the predefined temperature gradient threshold, control the electric motor to drive the drive shaft in rotation such as to vary the rotational speed of the drive shaft according to a second profile of rotational speed variation over time so that, when the rotational speed of the drive shaft lies within a critical interval of rotational speeds, acceleration of rotation of the drive shaft is greater than acceleration of rotation of the drive shaft according to the first profile of rotational speed variation over the same critical interval of rotational speeds, said critical interval of rotational speeds including a rotational speed likely to generate entry into resonance of the spool having regard to bowing of the drive shaft.

An aircraft comprising a gas turbine engine, the gas turbine engine comprising a spool comprising a compressor, a turbine and a drive shaft, the turbine being able to drive the compressor via the drive shaft, an electric motor able to drive the drive shaft in rotation, and a control module configured to:

• estimate a temperature gradient between a first portion of the spool and a second portion of the spool;
• compare the estimated temperature gradient with a predefined temperature gradient threshold;
• and
• if the temperature gradient is less than the predefined temperature gradient threshold, drive the drive shaft in rotation at a rotational speed varying over time according to a first profile of rotational speed variation;
• and
• if the temperature gradient is greater than the predefined temperature gradient threshold, control the electric motor to drive the drive shaft in rotation such as to vary the rotational speed of the drive shaft according to a second profile of rotational speed variation over time so that, when the rotational speed of the drive shaft lies within a critical interval of rotational speeds, acceleration of rotation of the drive shaft is greater than acceleration of rotation of the drive shaft according to the first profile of rotational speed variation over the same critical interval of rotational speeds.