This
model represents the turbine‐governor droop (R), the main steam control valve
motion and limits (T 1 , V MAX , V MIN ) and has a single lead‐lag block (T 2 /T 3 )
representing the time constants associated with the motion of the steam through
the reheater and turbine stages. The ratio, T 2 /T 3 , equals the fraction of the turbine
power that is developed by the high‐pressure turbine stage and T 3 is the reheater
time constant