An aircraft propulsion system is disclosed and includes a first gas turbine engine including a first input shaft driving a first gear system, a first fan driven by the first gear system, a first generator supported on the first input shaft and a fan drive electric motor providing a drive input to the first fan, a second gas turbine engine including a second input shaft driving a second gear system, a second fan driven by the second gear system, a second generator supported on the second input shaft and a second fan drive electric motor providing a drive input to the second fan and a controller controlling power output from each of the first and second generators and directing the power output between each of the first and second fan drive electric motors.

The present disclosure is directed to a method of control of a gas turbine engine comprising a fan section coupled to a low turbine together defining a low spool, an intermediate compressor coupled to an intermediate turbine together defining an intermediate spool, and a high compressor coupled to a high turbine together defining a high spool. The method includes providing an intermediate spool speed to low spool speed characteristic curve to a controller; providing a commanded power output to the controller; providing one or more of an environmental condition to the controller; determining, via the controller, a commanded fuel flow rate; determining, via the controller, a commanded intermediate compressor loading; and generating an actual power output of the engine, wherein the actual power output is one or more of an actual low spool speed, an actual intermediate spool speed, an actual high spool speed, and an actual engine pressure ratio.

Herein provided are methods and systems for controlling an engine having a variable geometry mechanism. A pressure ratio between a first pressure at an inlet of the engine and a predetermined reference pressure is determined. An output power for the engine is determined. The output power is adjusted based at least in part on the pressure ratio to obtain a corrected output power. A position control signal for a variable geometry mechanism of the engine is generated based on the corrected output power and the pressure ratio. The position control signal is output to a controller of the engine to control the variable geometry mechanism.

A control system for limiting power turbine torque (QPT) of a gas turbine engine includes a controller including a processor and memory configured to control the gas turbine engine, the controller including an engine control module that provides an effector command signal to a gas generator of the gas turbine engine; a power turbine governor module that outputs a preliminary torque request (QPT_req_pre); and a power turbine torque (QPT) optimal limiter module that outputs a maximum torque topper (QPT_max) to limit a power turbine speed overshoot of the gas turbine engine; wherein the controller outputs a minimum value between the preliminary torque request (QPT_req_pre) and the maximum torque topper (QPT_max) to the engine control module.

An aircraft propulsion system is disclosed and includes a first gas turbine engine including a first input shaft driving a first gear system, a first fan driven by the first gear system, a first generator supported on the first input shaft and a fan drive electric motor providing a drive input to the first fan, a second gas turbine engine including a second input shaft driving a second gear system, a second fan driven by the second gear system, a second generator supported on the second input shaft and a second fan drive electric motor providing a drive input to the second fan and a controller controlling power output from each of the first and second generators and directing the power output between each of the first and second fan drive electric motors.

Control systems and methods suitable for combination with power production systems and methods are provided herein. The control systems and methods may be used with, for example, closed power cycles as well as semi-closed power cycles. The combined control systems and methods and power production systems and methods can provide dynamic control of the power production systems and methods that can be carried out automatically based upon inputs received by controllers and outputs from the controllers to one or more components of the power production systems.

Methods and systems for controlling an engine having a variable geometry mechanism are described. An output power of the engine is determined. A speed of the engine is determined. A temperature-independent position control signal for the variable geometry mechanism is generated based on a power-to-speed ratio, the power-to-speed ratio obtained by dividing the output power by the speed. The position control signal is output to a controller of the engine to control the variable geometry mechanism.

An auxiliary power unit (APU) control system for an aircraft is disclosed and includes an APU, an air inlet having an effective area, an air inlet door moveable to vary the effective area of the air inlet, an actuator configured to move the air inlet door into a set position, one or more processors, and a memory coupled to the one or more processors. The memory stores data comprising a database and program code that, when executed by the one or more processors, causes the APU control system to receive one or more ambient signals indicative of an air density value. The system also determines the effective area of the air inlet based on the air density value. The system is further caused to instruct the actuator to move the air inlet door into the set position.

Methods and systems for operating an auxiliary power unit (APU) of an aircraft are described. The method comprises obtaining external environment parameters of the aircraft, determining an available output power for the APU as a function of the external environment parameters, and setting an overcurrent protection threshold of the APU to a level associated with the available output power.

A device for temporarily increasing power in order to increase the power from at least one first turbine engine and from at least one second turbine engine, the device including a tank of coolant liquid, a first injection circuit connected to the tank and leading to at least one injection nozzle configured to be installed upstream from the first turbine engine, a second injection circuit connected to the tank and leading to at least one injection nozzle configured to be installed upstream from the second turbine engine, each of the first and second injection circuits including at least one first valve and at least one second valve arranged upstream from said at least one first valve, and a bridge pipe connecting together the first injection circuit and the second injection circuit upstream from their respective first valves and downstream from their respective second valves.