摘要:This paper presents a modelling approach for theTransmission Network Expansion Planning (TNEP) problemthat considers security constraints through WeightedTransmission Loading Relief (WTLR) nodal indexes. Smallscale generation was also included as a complement tocandidate solutions to the TNEP. Additionally, this workdescribes a multi-objective approach for minimizing operatingand investment costs while maximizing network security. Thelatter is modeled through WTLR nodal indexes that allow tomeasure the severity of overloads under normal operatingconditions as well as under contingencies. Two differentmetaheuristics are implemented and compared: NondominatedSorting Genetic Algorithm II (NSGA-II) and ParetoEnvelope-based Selection Algorithm II (PESA-II). Bothtechniques enable to find a set of solutions that represent atrade-off between the two objective functions (costs vs.security), over which the system planner is able to makedecisions according to a given budget and security target. Theresults of the Garver’s system and a benchmark IEEE powersystem support the applicability of the proposed model and theeffectiveness of both metaheuristics.