Authors:
S.M. Amado, A.S. Kligerman, M.E.P Maceira, M.P. Raymond, A. Robitaille
Hydro 2000 Conference, August 2 - 4, 2000; Swizterland
Abstract
The Brazilian power system has continental dimensions and is composed of two large interconnected systems. The first corresponds to the South, Southeast and Middle-West Regions and the second, to the Northeast and part of the North Region. Since December 1998, a 500 kV, 1000 MW, 1000 km is interconnecting these two systems.
The system is hydro dominated (more than 90% of the installed capacity) and characterized by large reservoirs presenting multi-year regulation capability, arranged in complex cascades over several river basins. The hydro plants use stored water in the reservoirs to produce future energy to be generated, replacing fuel costs from the thermal units. But the future water inflows present a stochastic behavior with dry periods greater than one year. The limited reservoir volumes plus the variability of future inflows imply a link between an operating decision in a given stage and the future consequences of the decision.
Furthermore, the dispatch daily programming has to take into account the thermal and hydro unit commitment.
