Research on Low-cost Multi-stage High-risk Attack Strategy for Power Cyber-Physical System

The deep integration of the cyber layer and the physical layer is an important feature of a smart grid. Attacks carried out using cross-domain relationships bring new risks to the stable operation of the power grid. It is of great significance to study the high-risk attack strategy for improving the ability of power grids to resist attacks considering the attack cost factors. Firstly, based on the coupling relationship between cyber layer and physical layer, an index of line attack cost is defined by combining the structure characteristics and operation characteristics, so as to identify the low-attack-cost lines with weak protection measures in the power grid, which are vulnerable to attacks. Then, the multi-stage attacks on low-attack-cost lines are carried out to induce blackouts, and the damage amplification mechanism of the multi-stage attack under the interaction of cyber and physical systems is analyzed. Finally, an IEEE 118-bus system and a provincial power system are taken as examples for simulation analysis. Simulation results show that multi-stage attacks on low-attack-cost lines can cause blackouts,and the attack cost is obviously lower; the increase of failure probability of information nodes will improve the effectiveness of the attack strategy, and information network plays an important role in preventing blackouts. © 2021 Automation of Electric Power Systems Press.