Patent ID: 11873766
Assignee: RTX CORPORATION
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F  B  Y | IPC F

Claim 0:
1. A gas turbine engine assembly comprising:
a main gas turbine engine including a compressor section communicating compressed air to a combustor section where fuel is combined with the compressed air and ignited to generate a high energy flow that expands through a turbine section, wherein the turbine section is coupled to the compressor section by a main shaft;
an auxiliary power unit including an APU compressor coupled to an APU turbine section along an APU drive shaft;
a differential gear system including a ring gear and planet gears supported within a carrier attached to the ring gear, wherein the APU drive shaft is engaged to the planet gears;
a first drive means engaged to drive the ring gear;
an output shaft engaged to the planet gears; a generator driven by the output shaft;
a second drive means coupled to the main shaft of the main gas turbine engine for applying a partial drive load to the main shaft; and
a controller configured to control operation of the first drive means, the auxiliary power unit and the generator, where the controller is configured to: based on a determination that an increase in a demand for power on the generator is below a threshold demand, increase a speed of the first drive means to increase a power output from the generator to meet the demand while maintaining the APU at a constant speed; and based on a determination that the demand for power is above the threshold, increase the speed of the APU to increase the power output from the generator to meet the demand for power.