Patent ID: 8561413
Filing Date: 2013-10-22
Classification: F02C,F05D

Abstract:
1. A gas turbine engine system comprising: a low-pressure (LP) shaft; a high-pressure (HP) shaft; a constant speed mechanical drive assembly having an input and an output, the input mechanically coupled to the LP shaft, the output mechanically coupled to a constant frequency (CF) electrical generator, said CF electrical generator electrically coupled to a CF electrical bus and configured to supply CF electrical energy to said CF electrical bus; and an accessory gearbox assembly having an input and an output, the input mechanically coupled to the HP shaft, the output mechanically coupled to a variable frequency (VF) electrical generator, said VF electrical generator electrically coupled to a VF electrical bus, wherein said VF electrical generator draws a first amount of mechanical energy from the HP shaft, and wherein using said CF electrical generator to supply CF electrical energy to said CF electrical bus reduces the amount of mechanical energy drawn from the HP shaft during a descend mode.