Experimental identification and verification for a comprehensive model of multi-shaft combined cycle power plant

This paper investigates overall modeling and experimental identification and verification of a multi-shaft combined cycle power plant (CCPP). Models for subsystems of CCPP are given which can simulate each unit's behavior during steady state, as well as transient conditions. Some standard models such as GGOV1, CIGRE model for HRSGs, and AC7 are described and their pros and cons are mentioned. A comprehensive test procedure with practical considerations is introduced and important issues regarding the test procedure and modeling in such a power plant are described in this paper. The paper discussed endeavors to cover most of the practical challenges during real-time parameter's identification process in such a power plant. In order to test the models' efficacy and accuracy, a 345 MW multi-shaft CCPP has been selected as the case study. Developed models for each component such as gas turbine (GT), heat recovery system generator (HRSG), steam turbine (ST), etc. are studied. A comparative evaluation of field test results extracted from the monitoring system of the plant and simulation results by the proposed model are carried out for different nominal conditions in order to verify the authenticity of the identified models. Finally, a comprehensive model of multishaft CCPP is introduced and its precise validity conditions are described in details. This proposed model can be used in dynamic and stability studies of the power grid.