A New Approach to Medium-Term Hydrothermal Planning Using Reference Trajectories and Quadratic Programming

The present work aims to present a new approach applied to medium-term hydrothermal planning by utilizing reference curves of stored energy. In this regard, the decision-making process regarding water depletion or storage in Energy Equivalent Reservoirs will be based on preferred ranges. To validate the feasibility of curves in medium-term planning, we modelled a partitioned nonlinear optimization problem, where the objective function is to minimize the total operation cost, represented by thermal power plants and energy deficits, and consider the quadratic deviation of stored energies at each stage from the preferred ranges. Regarding the simulations, the four subsystems of the Brazilian National Interconnected System with their respective equivalent reservoirs, along with all thermal power plants and energy exchanges, were considered. Finally, the results demonstrate the applicability of reference curves in operational planning, ensuring operational and water security.