Articolo in rivista, 2020, ENG, 10.1016/j.jprocont.2020.08.006

An optimal hierarchical control scheme for smart generation units: an application to combined steam and electricity generation

Stefano Spinelli, Marcello Farina, Andrea Ballarino

Istituto di Sistemi e Tecnologie Industriali Intelligenti per il Manifatturiero Avanzato, Consiglio Nazionale delle Ricerche, Italy, Milano Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Italy, Milano

Optimal management of thermal and energy grids with fluctuating demand and prices requires to orchestrate the generation units (GU) among all their operating modes. A hierarchical approach is proposed to control coupled energy nonlinear systems. The high level hybrid optimization defines the unit commitment, with the optimal transition strategy, and best production profiles. The low level dynamic model predictive control (MPC), receiving the set-points from the upper layer, safely governs the systems consid- ering process constraints. To enhance the overall efficiency of the system, a method to optimal start-up the GU is here presented: a linear parameter varying MPC computes the optimal trajectory in closed-loop by iteratively linearising the system along the previ- ous optimal solution. The introduction of an intermediate equilibrium state as additional decision variable permits the reduction of the optimization horizon,while a terminal cost term steers the system to the target set-point. Simulation results show the effectiveness of the proposed approach.

Journal of process control , pp. 58–74

Keywords

Hierarchical Control, Model Predictive Control, Optimal Management, Thermal and Energy Grids

CNR authors

Spinelli Stefano, Ballarino Andrea

CNR institutes