Probabilistic transmission expansion planning considering risk of cascading transmission line failures

Recent studies have shown that power system blackouts occur much more likely than might be expected, and their probability distribution follows power law. Cascading outages have been reported as the major cause of the large blackouts; therefore, the risk of cascading outages is significant and should be considered in operating and planning assessments of the power systems. The Oak Ridge National Laboratory, Power Systems Engineering Research Center and University of Alaska (OPA) is a model developed on the basis of self-organized criticality to study cascading outages of transmission lines. In this paper, a modified version of the OPA model is used for considering risk of cascading transmission line outages in transmission expansion planning. The proposed method finds a set of effective candidate lines having higher capability for suppressing cascading outages; then, the original OPA is exploited over the planning horizon to analyze long-term reliability of the system. The benefit of each prospective transmission line is derived by the following two innovations in calculating the risk of blackouts: (i) the power law for finding the probability of blackouts; and (ii) a nonlinear estimation of the cost of the blackouts. Accordingly, the savings associated to each candidate line is calculated. These values are used to find the optimal plan using benefit/cost analysis. Two IEEE test systems are investigated to examine the applicability and scalability of the proposed method. The investigations revealed that the proposed method provides more effective scenarios, which entail considerable saving to society. Copyright (c) 2014 John Wiley & Sons, Ltd.