G. Ferrari-Trecate, E. Gallestey, P. Letizia, M. Spedicato, M. Morari, and M. Antoine. Modeling and control of co-generation power plants: A hybrid system approach. Technical Report AUT02-01, Automatic Control Laboratory, ETH Zurich, 2002. http://control.ethz.ch/
In this paper the short term scheduling optimization of a combined cycle power plant isaccomplished by exploiting hybrid systems, i.e. systems evolvingaccording to continuous dynamics, discrete dynamics, and logicrules. Discrete features of a power plant are, for instance, thepossibility of turning on/off the turbines, operating constraintslike minimum up and down times and the different types of start upof the turbines. On the other hand, features with continuousdynamics are power and steam output, the corresponding fuelconsumption, etc. The union of these properties characterize thehybrid behavior of a combined cycle power plant. In order to modelboth the continuous/discrete dynamics and the switching betweendifferent operating conditions we use the framework of Mixed LogicDynamical systems. Then, we recast the economic optimizationproblem as a Model Predictive Control (MPC) problem, that allowsus to optimize the plant operations by taking into account thetime variability of both prices and electricity/steam demands.Because of the presence of integer variables, the MPC scheme isformulated as a mixed integer linear program that can be solved inan efficient way via dedicated software.