Twin-shaft gas turbine power generation system, and control device and control method for gas turbine system

摘要

The present invention is provided with: a high-pressure gas turbine (3H); a first rotating shaft (4H) connected to a compressor (1) and the high-pressure gas turbine; an electric motor (9) connected to the first rotating shaft (4H); a speed governor (13) for adjusting the amount of air taken into the compressor (1); a low-pressure gas turbine (3L); a second rotating shaft (4L) connected to the low-pressure gas turbine (3L); a synchronous power generator (7) connected to the second rotating shaft; a frequency converter (10) for converting the frequency of power transmitted between the synchronous power generator (7) and the electric motor (9); and a control device (12) for controlling the total output of the twin-shaft gas turbine (6) and the electric motor (9) by controlling the speed governor (13) and a frequency converter control device (11) for controlling the frequency converter (10), on the basis of a power output command value (18) for indicating the power to be outputted to an external system (50). It is thereby possible to provide a twin-shaft gas turbine power generation system and a control device and control method for a gas turbine system that can inhibit a reduction in efficiency caused by variation in the outside temperature.