Metodologia para o rateio do bloco hidráulico no planejamento hidrotérmico de médio prazo

Abstract

The efficiency in the operation of predominantly hydrothermal systems, as the Brazilian Interconnected System (SIN), is closely related to the execution of a consistent operation planning. The strategical decision models used in long term studies are capable to determine the operative politics that minimizes the operation costs and the risks of deficit by using an energy equivalent reservoirs modeling. This work deals with a proposal that may be coupled to a strategical decision model by the expected cost to go function, in order to allow the disaggregation of the subsystems’ into its the individual reservoirs, for every month and for each streamflow sequence. So, the proposal is the development of a model where it is possible to verify if the subsystems’ generation global goals, supplied for the strategical decision models, are reachable. To work in such way, the tool disaggregates the solution found for the energy equivalent systems to the individualized plants. The methodology has two modules: in the first one the optimal dispatch of the energy equivalent subsystems is done with an iterative linear programming routine and the global generation goals for each one of the subsystems are found, considering the energy interchange between them. The second module, is an individualized plants nonlinear optimizer modeled for dispatching the hydroelectric plants of each subsystem separately, in order to try to reach the generation goals defined by the previous module and to maximize the reservoirs’ levels. The innovation of this model is the individualized plants simulation module, which is not based on heuristic rules, but in a nonlinear programming routine (NLP). The use of optimization techniques diminish the interference of the user in the simulation process, since his knowledge is usually based on the experience acquired throughout the operation history. Moreover, the methodology dismisses the adaptation of the model whenever new operative politics are adopted. Thus, this model, after the validation process, may dawn as an alternative to the simulation model that is officially used by the Brazilian Electrical Sector (SEB), whose individualized plants simulation module is based on the politics of the parallel operation of the reservoirs.