Probabilistic Criterion for Expansion and Operation Planning

The Brazilian power grid has traditionally been designed and operated by means of a deterministic reliability criteria set. Although these criteria have successfully eliminated system constraints, they have also entailed higher costs, especially those concerning operation planning. That happens because such deterministic criteria allow quantitative and not-qualitative analysis. Their essential weakness is that they cannot recognize the probabilistic or stochastic nature of system behavior, of customers demands, or of a component failures. This article illustrates how probabilistic criteria can replace the existing deterministic approach. Detailed reliability analyses of different load levels in the electric power system of Parana state, Brazil, are used as case study. The proposed approach seems promising in terms of reducing the cost for operation and long-term planning. On the other hand, the system risk level will not experience any significant increase.