Research On Game Theory Based Cyber Attack-defense Strategies In Cyber Physical Power Systems

With the development of smart grid and the integration of power and communication network,the traditional power system has gradually developed into a cyber physical power system(CPPS).the increasing importance and diversity of power communication services directly affect the stability and safety of power system.The access of distributed measurement and control devices enriches the scope and implementation of power communication services.However,high-speed and wide-connected terminals and networks also create possibilities for cyber-attacks.Unlike traditional cyber-attacks in the Internet,the power communication networks are closely coupled with the operation of the physical power grid.Once attacked,wrong judgments and control instructions will misoperate the power infrastructure.According to the space-time transmission of power flow,the cascading damage of power grids will result in serious security and economic losses.Therefore,based on the mechanism of attack generation,propagation and destruction in the cyber physical space,the corresponding cooperative defense strategy needs to be put forward to ensure the safe and stable power operation.The above questions are aimed at in this paper,and detailed work is listed as follows.(1)Considering the overall structure and security situation of CPPS,the flow process of measurement and control data in CPPS is described in detail.On this basis,the intrusion process,destruction mode and consequence of cyber-attacks in CPPS are analyzed.According to various vulnerability characteristics and attack modes,the corresponding security defense methods are introduced in the information layer and power layer respectively.The distributed denial-of-service attack and false data injection attack are taken as examples,and the availability and integrity of data in power grid are taken as attack targets,the impact of cyber-attacks on the operation of power services is analyzed.(2)On the basis of the initial attack and defense mode in power grid,in order to construct the optimal defense strategy,considering the limited resources of both sides,the optimal attack and defense strategy of both sides under limited decision space and resources is solved by using double zero-sum game.On this basis,considering the mutual information understanding between the two sides,the changes of attack and defense strategies under different information symmetry and grid topology scale are analyzed,and the optimal deployment of defense resources is finally achieved.(3)Based on the theoretical analysis of the attack-defense model,the simulation method is adopted to test and verify the optimal attack and defense strategy.Firstly,a real-time co-simulation platform of CPPS based on RT-LAB and OPNET is built.According to the simulation requirements of cyber-attacks,the attack and defense module are constructed to form an attack-defense platform.The distributed denial-of-service attack in the information layer and load frequency control service in the power layer are taken as the case.Firstly the dissemination characteristics of cyber-attack in CPPS space are analyzed firstly.Secondly,firewall is deployed in the information layer based on game theory,and corresponding security recovery module is set up in the power layer to construct cooperative defense strategy of CPPS.This paper presents a mutually validated modeling and simulation method for the attack and defense strategy of CPPS,which has important significance for the realization of system security protection and stable operation,and provides technical reference for the application of CPPS security defense.