Locational Security Impact Factors for Risk-Constrained AC OPF

Probabilistic risk-based approaches to system security provide a quantitative measure to evaluate the security of system operation. However, incorporating the risk-based security index as a constraint into the optimal power flow problem results in a complex optimization problem, which is difficult to solve in a centralized manner for large-scale power systems. In this paper, the application of so-called locational security impact factors to the AC model of a power system in order to decouple this optimization problem is studied. Locational security impact factors quantify the impact that the generation pattern has on system security, playing the same role for security as locational marginal prices do for economics. The IEEE 24-bus test system is used to compare the results obtained by the decoupled and centralized approaches with respect to the solution accuracy and simulation time.