Unidentifiable Attacks in Electric Power Systems

The electric power grid is a crucial infrastructure in our society and is always a target of malicious users and attackers. In this paper, we first introduce the concept of unidentifiable attack, in which the control center cannot identify the attack even though it detects its presence. Thus, the control center cannot obtain deterministic state estimates, since there may have several feasible cases and the control center cannot simply favor one over the others. Furthermore, we present algorithms to enumerate all feasible cases under an unidentifiable attack, and propose an optimization strategy from the perspective of the control center to deal with an unidentifiable attack. We briefly evaluate and validate our enumerating algorithms and optimization strategy.