A tri-level optimization model for power systems defense considering cyber-physical interdependence

Abstract

To seek the optimal defense strategy against malicious attacks, this paper proposes a novel defender–attacker–operator model applicable to the cyber-physical power system. The proposed model considers the interdependence in functionality and topology of the cyber network and the power network as well as the cyber network's constraints. The defender aims to minimize the load curtailment caused by the attacker, while the latter intends to maximize the power loss. The operator in the bottom level takes corrective action to minimize the attack consequence. This tri-level model is decomposed into a master problem and a subproblem, based on which the column-and-constraint generation algorithm is implemented to obtain the optimal solution. Comparative case studies based on IEEE RTS-79 system are carried out to demonstrate the advantage of the proposed method, and to investigate the impact of the energy coupling strength, the topologically independent link and the defensive resource. The effectiveness of this model is validated by the sensitivity analysis.