The report deals with the modelling and performance evaluation of thermal power plants. Two major types of thermal power plants were considered - conventional fossil fuelled steams units and combined gas and steam units. The models are implemented using simulation software simulink.

The developed models were validated with available literature. Dynamic simulation studies were carried out to evaluate plant performance during severe upsets such as a system separation. A comparison of the simulation results suggest that combined cycle power plants respond better and are more likely to survive under such conditions.

The developed model is used to design an islanding scheme for a realistic Industrial Combined Cycle Power plant setup. Different conditions of islanding are considered. A load shedding scheme based on under frequency and frequency drop rate has been designed and validated through simulation studies. Switching the governor from droop to isochronous mode will help in restoring system frequency following islanding.

The study shows that combined cycle generating stations can be safely runback to “house load”. The capability of gas turbine to transiently absorb torque from the system can be the key to plant survival under such conditions.