A power plant comprising two engine groups and a main power transmission gearbox. Each engine group drives the main gearbox mechanically in order to rotate a main rotor of an aircraft at a frequency of rotation NR. A first engine group comprising two main engines is regulated on a first setpoint NR* for the frequency of rotation NR, while a second engine group comprising a secondary engine is regulated on a second setpoint W.sub.2* for power of the second engine group. In addition, each engine operates with margins relative to operating limits. The second setpoint W.sub.2* for power is determined so that each secondary engine operates with a lowest second margin that is equal to the lowest first margin of the first engine group.

Systems and methods for detecting and accommodating for loss of a torque signal of a gas turbine engine are described herein. An engine deterioration offset may be determined while the torque signal of the engine is available. Then, in the event that the torque signal is lost, a predicted operating offset may be determined. A synthesized torque signal may be generated when the torque signal is lost at least in part from the engine deterioration offset and the predicted operating offset.

A control system for a gas turbine engine is disclosed. The control system may include a computer processor. The control system may also include an outer loop control module programmed into the computer processor to determine a torque request based at least in part on a real-time collective lever angle command. The control system may also include an inner loop control module programmed into the computer processor to receive the torque request from the outer loop control module, to determine fuel flow and inlet guide vane schedules based at least in part on the received torque request, and to send signals to a gas generator of the gas turbine engine in order to control the gas generator according to the determined fuel flow and inlet guide vane schedules.

A fuel control system is provided for a gas turbine engine having a core engine comprising at least one core engine spool in which a compressor and a turbine are interconnected by a shaft. The system includes a first engine sensor which determines a power output of the engine. The system further includes a control unit which is configured to compare the determined power output with a value of a power threshold, and to command a reduction in fuel supplied to the engine when the determined power output exceeds the power threshold value. The system further includes a second engine sensor which measures the rate of change of rotational speed of the core engine spool. The control unit is further configured to adjust the power threshold value as a function of the measured rate of change of speed of the core engine spool.

An electricity generation system according to an embodiment of the present invention includes an engine, an electric generator, a detector, and a control device. The engine has a compressor including a rotating shaft. The electric generator is connected to the rotating shaft and generates electricity with rotational force of the rotating shaft. The detector detects shaft torque of the electric generator. The control device controls an operational status of the engine or the electric generator on the basis of the shaft torque.

A torque converter is provided. The torque converter includes a turbine including a turbine shell and a plurality of turbine blades fixed to the turbine shell by tabs of the turbine blades. The turbine shell includes a rounded blade supporting portion supporting the turbine blades. The torque converter also includes an inertia ring and a connector fixing the inertia ring to the turbine shell. Some of the turbine blade tabs fix the connector to the turbine shell. A method of constructing a torque converter is also provided.

A method and control system for an aircraft using a gas turbine engine is provided. The control system includes a controller that includes a load and engine control modules and communicates control signals to a plant that includes a gas generator and a rotor load, an engine estimation module that receives engine state measurements and effector feedback/command signals from the controller and communicates a power turbine torque estimate, and a load estimation module that receives signals including the power turbine torque estimate, a first power turbine speed value, a first power turbine torque value, a second power turbine speed value, a second power turbine torque value, and a rotor speed value. The load estimation module generates one or more of a power turbine speed estimate, a power turbine torque estimate, and a rotor load estimate based on the received signals.

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.

The invention relates to a method for controlling a turbomachine comprising a gas generator, the turbomachine comprising an electric machine forming a device for injecting torque into/removing torque from one of the low pressure/high pressure rotation shafts of said gas generator. Said method comprises a step of implementing a fuel control loop in order to determine a fuel flow setpoint into the combustion chamber, and comprising, in the event that at least one operability limit is reached, determining a corrected fuel flow setpoint, said corrected fuel flow setpoint exhibiting a difference in relation to the setpoint. Said method also comprises a step of implementing a torque control loop in order to determine a torque setpoint for the electric machine, and comprising determining a torque correction quantity as a function of said difference, said torque setpoint being determined as a function of said torque correction quantity.

A regulator device for regulating a speed of rotation, of a shaft of a gas generator of at least one turboshaft engine of a rotorcraft. The rotorcraft has at least one main rotor for regulating at least lift and/or propulsion for said rotorcraft in the air; a control member for controlling a collective pitch of the blades of said at least one main rotor, said control member serving to generate a control setpoint for said collective pitch; at least one turboshaft engine suitable for driving rotation of said at least one main rotor, said at least one engine producing, at least temporarily, a drive torque that is transmitted to said at least one main rotor; and measurement means for taking at each instant a measurement of said drive torque transmitted by said at least one engine to said at least one main rotor.