Methods and systems for providing secondary power to aircraft systems. In one embodiment, an aircraft system architecture for providing power to an environmental control system includes an electric generator operably coupled to a jet engine. The jet engine can be configured to provide propulsive thrust to the aircraft, and the electric generator can be configured to receive shaft power from the jet engine. The environmental control system can be configured to provide outside air to a passenger cabin of the aircraft in the absence of bleed air from the jet engine.

Electric-based secondary power system architectures for aircraft

An aircraft mounted gas turbine engine system comprises a three shaft propulsive gas turbine engine having three electrical generators; each one respectively associated with one shaft of the engine. Two of the electrical generators are additionally configured so as to function as electric motors so as to facilitate power transfer between the engine shafts. One of the electric generators provides the primary source of electrical power for the aircraft, while the remaining electrical generators provide electrical power for the engine and back-up power for the aircraft.

Gas turbine engine system

An engine power extraction control system controls the main propulsion engines and the electrical machines that are coupled thereto to supply an appropriate amount of aircraft thrust and electrical energy to the aircraft. The engines and electrical machines are also controlled so that the propulsion thrust that is generated is split between the various turbines in the main propulsion engines to maintain an adequate surge margin and to minimize residual thrust generation.

Engine power extraction control system

A turbofan gas turbine propulsion engine includes a multi-speed transmission between the high pressure and low pressure turbines and associated high pressure and low pressure starter-generators. The multi-speed transmission reduces the operating speed range from the low pressure turbine to its associated starter-generator, and is configurable to allow the starter-generator associated with the low pressure turbine to supply starting torque to the engine.

More electric aircraft starter-generator multi-speed transmission system

The invention relates to a turbomachine of axis X including a compressor and an integrated starter/generator. The field magnetic circuit of the starter/generator is mounted in the bore of at least one disk of the compressor and surrounds the secondary magnetic circuit which is secured to a cylindrical shroud provided on the support structure for the bearing of the compressor. The invention applies in particular to single-shaft or multi-shaft turbomachines.

Integrated starter/generator for a turbomachine

An integrated aircraft power unit providing the electrical and other forms of energy needed during auxiliary power unit operating conditions-while the aircraft is on the ground, and also providing airborne or emergency power including high altitude flight emergency conditions power wherein the power unit uses an oxidant supply carried by the aircraft. In this high altitude operating condition the power unit provides lower electrical output, but lower losses and improved efficiency over previous power units. The disclosed power unit includes separate electromechanical transducers or motor generator devices coupled to a segregated pair of rotational shaft members, one for the inlet or compressor fan and one for the outlet or exhaust turbine fan with electrical coupling and then friction clutch coupling of these shafts accomplished for low altitude high energy output operation of the power unit. The described power unit is also capable of providing these aircraft energy needs with a minimum of physical changes from conventional integrated aircraft power units.

James S. Tschantz

Papers

Aircraft power unit with elective mechanical coupling