Trilevel Optimization in Power Network Defense

We present a trilevel optimization model of resource allocation in electric power network defense. This model identifies the most critical network components to defend against possible terrorist attacks. The goal of defense is to minimize the economic cost that the attacks may cause, subject to resource constraints. We describe a decomposition approach for finding an optimal solution to the trilevel model, which is based on iteratively solving smaller nested bilevel problems. Our testing results demonstrate the advantages of trilevel optimization over bilevel optimization in network defense.