Hierarchical control of large scale systems: A zone control approach

A methodology for hierarchical control of large scale systems is presented. This approach uses an integration of dynamic real time optimization (DRTO) and model predictive control (MPC) with zone control (coordinator). The dynamic real time optimization problem is solved in the upper layer and addresses the overall economic objective to provide the reference trajectories for the coordinator (middle layer) that calculates hierarchical input variables and output references that are always into the designed zone, this information is taken by the subsystems controllers (lower layer) to generate the input variables that is going to be applied, and that reach the reference that the coordinator generate. This methodology is applied to a complete chemical process composed by three chemical reactors type CSTR (Continuous Stirred Tank Reactor) and three non reactive binary distillation columns.