The simplest steam turbine model is the TGOV1 model shown in Figure 2‐1. This model represents the turbine‐governor droop (R), the main steam control valve motion and limits (T1, VMAX, VMIN) and has a single lead‐lag block (T2/T3) representing the time constants associated with the motion of the steam through the reheater and turbine stages. The ratio, T2/T3, equals the fraction of the turbine power that is developed by the high‐pressure turbine stage and T3 is the reheater time constant.
Figure