Resumo:
The main objective of the transmission expansion planning is to define where, when and what reinforcements should be placed int he electrical net work to ensure an adequate level of energy supply to
consumers, taking into account the load growth and new generator capacities. Usually, the expansion planning horizon is divided into short ,medium and long-term periods in accordance with the type of decisions to be made and with the quality of the available data and information involved in the planning process, eg., uncertainties and network modeling (AC and DC). In t he practical point of view, the major it y of techniques used to solve this problem are based on
deterministic methods. The main difficulty related to the application of probabilistic methods is dueto the need of pre-defining adequate reliability levels. One alternative to over come this difficulty, which is
being proposed in this work, is the inclusion of reliability worth in the planning process. This thesis proposes an approach t o solve expansion planning problems associated to transmission net work, inter connections and shuntreactive power devices. This methodology is based on mathematical heuristic, probabilistic evaluations and multi-criterion decisions comprising, besides the investment and real power loss costs, the reliabilit y worth, reliabilit y marginal costs, the congestion costs and penalties associated to equipment unavailability.
The expected Reliabilit y Marginal Costs are calculated from the Lagrangian Multipliers associated to the solution of non-linear optimal power flows in the reliability analyses carried out . They are utilized
inside an interactive planning scheme to choose, from the reliability view point the most adequate busbars to connect new transmission reinforcement (circuits and shunt devices) as well as to identify new
transmission corridors and associated voltage shunt reactive power levels. The efficiency of the proposed approach is verified from it s applicat ion in sever al case-studies with configurations of the transmission system of the CHESF Companhia Hidrelétrica do São Francisco and with the Brasilian Norther/Northeast network.
