Development and Modeling of Gas Turbine Model and Steam Turbine Model for Using Multi-Shaft Combined Cycle Power Plant Model

Abstract

There are various studies about the capability, performance and stability of combined
cycle power plant. Thus, the power plant model is important for the further studies.
Nowadays, there are several models that are acceptable and suitable for applying in the
real system. However, most of the models are the single-shaft combined cycle power plant,
focusing on studies of the gas turbine whereas only a few models of multi-shaft combined
cycle power plant is available. This article presents a modeling of multi-shaft combined
cycle power plant developed through DIgSILENT PowerFactory software by applying gas
turbine model which is proposed by W.I. Rowen to develop and combine steam turbine in
the system model. As a result the multi-shaft system model was functional. Studies of
developed model were carried out by simulating the dynamic stability when disturbance
events occur in the power system, for instance, the instantaneous changes of load and short
circuit faults occurred regularly in power system. The simulation results showed that the
developed model was accurate and consistent with the model in the reference document
so that it could be well used in power system studies. In addition, this developed model
could be applied the several number of turbines and generators.