Patent attributes
Gas turbine engines and methods of starting gas turbine engines, the gas turbine engine including: an electronic engine controller; one or more spools designated a starting spool for starting the engine, and has a required starting torque τs; a permanent magnet alternator mechanically coupled with the starting spool, the alternator, in a motor mode, provides a peak torque of τa, and, in a generator mode, generates electrical power for the electronic engine controller; and an electrical starter-generator mechanically coupled with the starting spool. The starter-generator in a motor mode, provides a peak torque of τsg, and, in a generator mode, generates electrical power for an external load. τsg+τa≥τs and τsg, τa<τs, and the electronic engine controller, during a start procedure, operates both the permanent magnet alternator and the starter-generator in a motor mode to drive the starting spool.
