It is reported that the gas turbines chain tripped out due to the big decline of the system frequency brought about a large-scale blackout in the foreign country. There is a need of the analysis of gas turbine dynamic behaviors during the large frequency disturbances from such a background. For this purpose a combined cycle plant model for power system dynamic simulation studies has been developed.
In this paper, the process physical relationships and model block diagrams are shown and the modeling method of multi shaft combined cycle plant is proposed. The dynamic behaviors of the plant in the system frequency change in addition to the static characteristic are considered. A comparative evaluations between field test results and simulation results by the model are described.