Dynamic models for fossil fueled steam units in power system studies

The objective of this work is to detail the model structures that apply to the speed-governing system and turbine and energy system, including special control logic and boiler effects for fossil fueled turbines. These model structures should be capable of establishing the dynamic response of the prime mover system´s mechanical power over a time span of fractions of a second to a few minutes as might be required to analyze effects of disturbances, especially those that involve significant prime mover control action. Control action can then transcend the normal near-linear behavior of governing systems under small perturbations, since overrides such as power load unbalance relays, emergency speed controls, fast valving, and initial pressure regulators come into play. An important factor is the steam supply system and its pressure controls. Various modes of coordinated boiler turbine control are in use, as are a number of implementations of variable pressure operation