A hierarchical controller for optimal load cycling of steam turbines

The availability of inexpensive base load power from independent power producers and nuclear plants has caused electric utilities to cycle their large steam turbines in an effort to reduce overall generation cost. In this paper, the authors present a hierarchical optimal strategy for controlling a turbine during load cycling. The approach uses heuristic turbine control rules to implement the higher level long term cost minimization strategy. At the second level a model based optimal controller is used to calculate the optimal actuator positions needed to track the desired power demand at minimum cost