A flexible approach to short-term hydro-thermal coordination. I. Problem formulation and general solution procedure

This paper presents a new flexible approach based on Lagrangian relaxation for solving the hydro-thermal coordination problem. Part I and Part II of this work make a complete theoretical and practical tool in order to solve this large scale, nonlinear, nonconvex and dynamic problem. The final result is an efficient and proven programming package within operation planning needs. Part I deals with the general problem formulation, with the application of the decomposition technique and with the primal problem solving. Methodological and modeling improvements are presented concerning costs of the excessive hydro production and advancements in the primal problem solving. The numerical simulations show flexibility of the proposed procedure which can be used to solve the short-term hydro-thermal coordination problem in completely different power systems.