Hamilton Sundstrand Corporation

Tarrence LaMar Mack

Michael E Mehrer

Gary Lester Goldberg

Peter J Suttie

Dennis E Schmidt

Paul E Hilgeman

Bing Tong

Timothy J Sullivan

The system and method of the present invention provides stepping speed control of a gas turbine engine to reliably light-off a gas turbine engine. During starting, the speed of the gas turbine engine is incremented by stepped amounts through the light-off window from a minimum speed value to a maximum speed value, with the speed of the gas turbine dwelling at each stepped value for a period of time before incrementing the speed of the engine to the next stepped level. If the gas turbine engine is stepped through the entire light-off window without success, the controller decreases the speed of the gas turbine engine to the minimum value and begins the process again. The process continues until successful light-off is initiated or until the light-off window is traversed a certain number of times, after which the start process is aborted.

Gas turbine starting with stepping speed control

A starting system and method for a gas turbine engine includes a controlled starter system and a controlled fuel system. The controlled starter motor is accelerated along an acceleration profile to a dwelling point. Concurrently with the starter motor spinning up the gas turbine engine rotor, the fuel system controller commands the pump motor to drive the fuel pump at a speed which fills the fuel line volumes and establishes adequate pressure for fuel atomization at light off. As the fuel pump motor and starter motor are independently controlled and coordinated the starter motor maintains the gas turbine engine at the predetermined dwelling point until ignition occurs. The starter motor also provides a controlled amount of assisting torque during acceleration of the gas turbine to minimize thermal transients which thereby increased the gas turbine engine operational life.

Controlled starting system for a gas turbine engine

An APU system provides an APU which drives a permanent magnet generator, an APU controller and a fuel controller. The APU controller controls the APU speed through communication with the fuel controller to maintain the generator voltage output within specified limits in response to an engine speed set point signal, a voltage set point signal and a voltage output signal.

Control system for an auxiliary power unit

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Santee, CA, United States of America

Tarrence LaMar Mack