Bi-level Modeling of Cyber-Attacks Induced Severe Line Overloads

Cyber-attacks aimed at terrorist incidents are able to bring about great security impacts on the operation of a power system. In this paper, we first introduce novel evaluation indexes for quantifying the flow redistribution impacts under line outage situations, and then a bi-level mixed integer linear programming (MILP) problem is proposed to investigate the worst line overloading scenario considering both the overload and outage faults. To solve this problem, we convert the bi-level optimization model into a single-level optimization model with the application of Karush-Kuhn-Tucker (KKT) conditions. Numerical simulation tests on the IEEE 118-bus system validate the feasibility and effectiveness of the proposed model. What’s more, our study is a critical vision guiding the efforts for the risk assessments of transmission line overloading contingencies when the cyber scenario is considered.