EFFICIENT LARGE-SCALE HYDRO SYSTEM SCHEDULING WITH FORCED SPILL CONDITIONS.

A general framework is presented for the formulation and solution of large-scale hydro system scheduling problems (h. s. s. p. ). A nonlinear programming formulation is used that permits the representation of virtually all types of constraints imposed on a hydroelectric system: the physical, operational, legislative or contractual constraints. The problem formulation explicitly represents the nonlinear relationship between spillage and the reservoir storage level. The proposed method is computationally efficient for determining optimal schedules for large river systems. Results on several cases including one with 3300 decision variables, 2200 linear equalities, 2700 linear inequalities and 200 nonlinear equality constraints, are presented.