Control of the gas composition in a gas turbine power plant with exhaust gas recirculation

The method involves dividing exhaust gases (19) into effluent stream (21) by exhaust gas divider (29), for recirculation into intake flow of gas turbine (6), and exhaust gas stream (20) for transfer to surroundings. The target concentration of component in exhaust gas stream and/or intake flow of gas turbine after mixing recirculated exhaust gases is determined based on operating state of gas turbine. The actual concentration of component in exhaust stream and intake stream is measured. The first exhaust gas stream is controlled by control element (11,29) based on desired and actual value. An independent claim is included for gas turbine power plant.