The impact of combined-cycle gas turbine short-term dynamics on frequency control

A model suitable for studying the short-term dynamic response of a combined-cycle gas turbine (CCGT) to a system frequency deviation is developed. The model is used in conjunction with a larger system model to study the impact of increasing levels of CCGT generation on frequency control of a small island system. The study considers single contingencies and does not consider severe cascading-type events. A consequence of the results is that as the number and proportion of base-loaded CCGTs increases, frequency control may become more challenging. The results indicate that with additional CCGTs on the system large frequency excursions will be more likely, and the transmission system operators on the island of Ireland should review their frequency control strategies in the future to avoid the shedding of customers.