Patent ID: 8479523

Claim:
A method of controlling output power produced by a gas turbine by driving an electric generator connected to an electrical utility grid with a rotational speed of a gas turbine synchronized to an electrical frequency of the electrical utility grid, wherein the gas turbine includes a compressor providing air to a combustor wherein fuel is combusted providing a hot gas path to drive a turbine, an extraction path for air passing through the compressor that supplies air for the gas turbine and a control for the extraction path for the air, the method comprising: providing a flowpath for air within the gas turbine including through the compressor providing the air to the combustor; mixing the air with the fuel in the combustor; powering the turbine rotatingly connected to the electrical generator electrically connected to an electrical utility grid; initiating air extraction from the flowpath for air within the gas turbine; and supplying power requirements on the electrical utility grid by raising power output from the gas turbine by increasing the fuel supply to the combustor until a limit on performance of the compressor is reached while maintaining a margin to a limit on performance of the compressor at the power output of the gas turbine by controlling an amount of air extraction from the flowpath for air.