Medium-Term Load Matching in Power Planning

The medium-term planning for a company participating in a pure pool market can be considered under different behavioral principles: cartel, endogenous cartel with respect to hydro generation, and equilibrium. One of the important aspects of the model is the medium-term load matching, where load is represented by the load duration curves of each period into which the medium-term horizon is subdivided. The probabilistically exact Bloom and Gallant formulation of load matching could be employed, but its exponential number of load-matching inequality constraints limits its use to small cases. A heuristic has been proposed where only a small subset of the load-matching constraints, hopefully containing the active ones at the optimizer, is employed. This heuristic does not perform totally well with the more complex models, as those of endogenous cartel and equilibrium behavior, and a more comprehensive heuristic procedure is presented here. A well-known alternative method of medium-term load matching is the multi-block approximation to the load duration curve. The three load-matching techniques mentioned above are here described and are compared, and computational results for realistic systems are analyzed for the different behavioral models, showing the advantages of each procedure.