PRESSURE CONTROL METHOD AND SYSTEM TO REDUCE GAS TURBINE FUEL SUPPLY PRESSURE REQUIREMENTS

PROBLEM TO BE SOLVED: To provide a system and method to reduce gas fuel supply pressure requirements of a gas turbine.SOLUTION: The system and method results in an increased operability range and a reduction in gas turbine trips. According to the method, the gas turbine is allowed to start and operate at supply pressures determined as a function of outside air conditions and gas turbine compressor pressure ratio. This increases the operability window, and reduces or eliminates the need for gas fuel compressors. The method comprises: determining a first required fuel pressure at upstream side to fuel nozzles; determining a minimum allowable pressure requirement at upstream side of a gas control valve on the basis of the first required fuel pressure; and determining a fuel pressure reference for control of a pressure control valve on the basis of the minimum allowable pressure requirement.