Unit Commitment in a Large-Scale Power System including Fuel Constrained Thermal and Pumped-Storage Hydro

This paper presents a new method for solving efficiently a large-scale optimal unit commitment problem. Our problem includes three types of units (i) usual thermal units, (ii) fuel constrained thermal units and (iii) pumped-storage hydro units. The solution method uses a Lagrangian relaxation. For maximizing the Lagrangian function, a ´variable metric method´ is tried instead of the subgradient method. Moreover, a new device for efficiently obtaining a feasible solution is proposed. This leads to very good numerical results. All important operating constraints are incorporated.