Method for operating a power plant, and power plant

A power plant comprising:

• at least one gas turbine engine;
• at least one fuel gas compressor having an upstream end connected to a utility supply line;
• a plant supply line connecting a downstream end of the at least one fuel gas compressor and the at least one gas turbine engine;
• and
• a fuel gas pressure control system and a gas turbine engine control system, wherein a control line is provided from the fuel gas pressure control system to the gas turbine control system and is adapted and configured to forward a fuel gas compressor failure signal from the fuel gas pressure control system to the gas turbine engine control system;
• and wherein the gas turbine engine control system is adapted and configured to, in response to the fuel gas compressor failure signal, forward a preset feedforward emergency control signal at least to at least one fuel flow control valve of the at least one gas turbine engine.

A method for operating a power plant, the power plant comprising at least one gas turbine engine and at least one fuel gas compressor, the method comprising:

• supplying fuel gas through a utility supply line, wherein the fuel gas in the utility supply line is at a line supply pressure;
• compressing the fuel gas to a plant supply pressure in one or more operating fuel gas compressors of the at least one fuel gas compressor and supplying the compressed fuel gas to a plant supply line;
• operating the at least one gas turbine engine to generate a power output, wherein the power output is a set power output according to a power demand signal;
• detecting whether one of the one or more operating fuel gas compressors has a failure;
• and, upon detecting the failure of the one of the one or more operating fuel gas compressors, reducing the power output of the at least one gas turbine engine to an emergency power output which is lower than the set power output and restricting the power output of the at least one gas turbine engine to the emergency power output, wherein the reduction of the power output is performed in one single step and controlled by at least one feedforward control signal;
• providing the at least one feedforward control signal to at least one fuel flow control valve of the at least one gas turbine engine and changing a position of the at least one fuel flow control valve to a predetermined emergency position, wherein the predetermined emergency position of the at least one fuel flow control valve is a valve position corresponding to an expected position of the at least one fuel flow control valve at the emergency power output;
• and
• subsequently operating the at least one gas turbine engine in a load control mode at the emergency power output.