Research on risk prevention and control strategy of power grid CPS system based on intrusion tolerance

Abstract

In this paper, an information-physical risk prevention and control framework based on intrusion tolerance technology is proposed, which is a multi-stage in-depth defense system for the risk interaction mechanism and evolution process in the power information-physical fusion system, the aim of this paper is to improve the survivability of the system under attack and minimize the loss caused by the risk through multi-phase defense strategy. At the same time, according to the phase characteristics of risk propagation in CPS, a safe operation state transition model considering intrusion tolerance is established. In order to contain the critical failure events in the risk evolution process of the information-physics fusion system, according to the risk development characteristics of the information-physics system under attack, this paper presents a self-organized critical state identification method, which integrates the characteristics of physical network power flow and information network traffic flow, in order to identify the critical nides that make CPS system enter the self-organized critical state under network attack. Finally, according to the characteristics of CPS dependent network structure and the self-organized critical characteristics of risk evolution, the protection strategies of strengthening the protection of key nodes, adjusting the coupling state of dependent edges and adding autonomous nodes are formulated, by considering the decision-making model of risk prevention and control strategy in the game of attack and defense, the current defense resources are reasonably allocated.