AN INNOVATIVE APPROACH TO GENERATION SCHEDULING IN LARGE-SCALE HYDROTHERMAL POWER-SYSTEMS WITH FUEL CONSTRAINED UNITS

This paper proposes a new methodology for the short-term unit commitment. The development of the solution method is based on the Lagrangian Relaxation approach. Thermal, fuel constrained and hydro units have been modeled in the formulation of the problem, and restrictions on fuel and water utilizations as well as the limits on the storage levels of reservoirs are included. This procedure is specially applicable to systems whose unit commitment solution is sensitive to changes in the Lagrangian multipliers. In this regard, the proposed method incorporates the following special features. First, a set of upper bounds is added to limit the excess in the spinning reserves at different periods during the search for a feasible suboptimal solution. Second, a revised economic dispatch algorithm is introduced in the final stage of the method. This algorithm identifies unnecessarily committed units in the generation schedule of a large power network, and provides the solution for the economic allocation of the system demand among the committed units. © 1990 IEEE