Methods for protecting turbochargers of engine systems include determining a speed gradient of the turbocharger and implementing a turbocharger speed protection action if the determined speed gradient is above a speed gradient threshold. Implementing a protection action comprises limiting engine torque, engine speed, vehicle speed, and/or fuel injection to the engine. The method can further include determining a cold start condition prior to determining the speed gradient of the turbocharger. A cold start condition can be determined based on ambient temperature, engine oil temperature, or engine coolant temperature. The method can further include, subsequent to implementing the turbocharger speed protection action, disabling the turbocharger speed protection action when a subsequently determined turbocharger speed gradient is below the speed gradient threshold. Systems for implementing the methods are also disclosed.

A method of starting a gas turbine engine having a rotor comprising at least a shaft-mounted compressor and turbine, with a casing surrounding the rotor includes an acceleration phase, a bowed-rotor cooling phase, during the acceleration, and a combustion phase. The bowed-rotor cooling phase comprises a time where the rotational speed of the rotor is maintained below a bowed-rotor threshold speed until a non-bowed condition is satisfied, wherein the air forced through the gas turbine engine cools the rotor. The combustion phase occurs after the bowed-rotor cooling phase and upon reaching the combustion speed, wherein fuel is supplied to the gas turbine engine.

Methods for protecting turbochargers of engine systems include determining a speed gradient of the turbocharger and implementing a turbocharger speed protection action if the determined speed gradient is above a speed gradient threshold. Implementing a protection action comprises limiting engine torque, engine speed, vehicle speed, and/or fuel injection to the engine. The method can further include determining a cold start condition prior to determining the speed gradient of the turbocharger. A cold start condition can be determined based on ambient temperature, engine oil temperature, or engine coolant temperature. The method can further include, subsequent to implementing the turbocharger speed protection action, disabling the turbocharger speed protection action when a subsequently determined turbocharger speed gradient is below the speed gradient threshold. Systems for implementing the methods are also disclosed.

A method of thrust reversal operation according to an example of the present disclosure includes, among other things, permitting an increase in engine power when at least one criterion is not met and a thrust reverser is deployed, and denying the increase in engine power when the at least one criterion is met. A system for thrust reversal is also disclosed.

A pump station arrangement and a method for turning off a pump configured for pumping liquid via a conduit. The pump, before being turned off, being driven at an operational frequency (F.sub.N) by a control unit. The method is characterized by the steps of, ramping down the frequency of the pump due to a turn off instruction, the terminal frequency of the ramping down being equal to the operational frequency (F.sub.N) of the pump minus at least 10 Hz and the ramping down time being at least a reflection time (T.sub.R) for the conduit in question, and the terminal frequency of the ramping down not being less than 10 Hz, and stopping the pump after the ramping down.

In accordance with one aspect of the present technique a method includes receiving at least one of a speed and an acceleration of a rotating component in a rotating machine. The method includes determining whether at least one of the speed and the acceleration of the rotating component exceeds a non-trip operating (NTO) space in a speed-acceleration plane, wherein the NTO space is based on a trip overshoot model. The method further includes sending a notification for tripping the rotating machine in response to determining that at least one of the speed and the acceleration of the rotating component exceeds the NTO space.

A method of stopping an engine of a rotorcraft in overspeed, the engine comprising a gas generator and a power assembly. When the engine is in operation, a relationship is established giving a limit derivative that varies as a function of the speed of rotation of the power assembly. The speed of rotation, referred to as the current speed, reached by the power assembly is measured and the time derivative of the speed of rotation is determined and referred to as the current derivative. The engine is stopped automatically when the limit derivative corresponding to the current speed as determined by the relationship is less than or equal to the current derivative.

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 pump station arrangement and a method for turning off a pump configured for pumping liquid via a conduit. The pump, before being turned off, being driven at an operational frequency (F.sub.N) by a control unit. The method is characterized by the steps of, ramping down the frequency of the pump due to a turn off instruction, the terminal frequency of the ramping down being equal to the operational frequency (F.sub.N) of the pump minus at least 10 Hz and the ramping down time being at least a reflection time (T.sub.R) for the conduit in question, and the terminal frequency of the ramping down not being less than 10 Hz, and stopping the pump after the ramping down.