P?riority evaluation and ranking of transmission system projects: computer models and results

The authors describe a methodology for identifying which subset of transmission investments in a given expansion plan can be postponed in order to meet a preestablished budget constraint with the least possible impact on the system performance. The methodology is based on the ranking of scheduled reinforcements by a cost/benefit index. The cost corresponds to the deterioration of operating conditions (e.g., increased risk of load curtailment) if the equipment is postponed. The benefit is associated with the financial relief brought by the postponement. A computational package for determining this ranking has been developed and is being used by the Brazilian utilities as a subsidy for deciding the adjustment of their expansion plans. The methods described are illustrated using a reduced test system (40 buses) based on the Brazilian HV/EHV Southern network. It is applied to two large-scale power systems, also belonging to the Brazilian EHV network.<>