Gas turbine power generation system and control system used in the same

A gas turbine power generation system comprising:

• a dual-shaft gas turbine;
• an electric generator mechanically connected to a low pressure turbine of the dual-shaft gas turbine and electrically connected to an electric power system;
• a rotary electric machine mechanically connected to a high pressure turbine through a compressor of the dual-shaft gas turbine and electrically connected to the electric power system;
• wherein a power oscillation in the electric power system is suppressed by operation of the rotary electric machine as a motor or as a generator
• wherein the operation of the rotary electric machine adjusts a power including an active power and a reactive power,
• a frequency converter electrically connected between the rotary electric machine and the electric power system;
• wherein the rotary electric machine is operated by the frequency converter,
• a control system controlling the frequency converter to adjust the power including the active power and the reactive power output from the frequency converter for suppression of the power oscillation in the electric power system;
• wherein the power oscillation in the electric power system includes an inter-system power oscillation, and the inter-power oscillation is a power fluctuation, having frequency of 0.3˜0.5 Hz, generated among power systems,
• wherein the control system is set in an inter-system power oscillation control mode for suppression of the inter-system power oscillation,
• wherein the control system controls the frequency converter to adjust the active power or both of the active power and the reactive power when the control system is set in the inter-system power oscillation control mode on the basis of a voltage and a current at an output of the gas turbine power generation system and a voltage and a current of the frequency converter on a side of the electric power system.