Research On The Attack-Defense Game Of Cyber Physical Power System Based On Attack Behavior Analysis

The integration of smart grid technology has deepened the link between the traditional physical grid and information network,eventually evolving into a cyber physical system(CPS).The emergence of power communication businesses has raised security and safety risks,yet has also improved grid performance.The information network is highly coupled with the power grid,and all parts of the system exchange and transfer information in the information network,so the power system becomes more complex and open,more vulnerable to external interference and even malicious attacks.The potential for a serious chain reaction to occur when the power communication network is maliciously infiltrated,resulting in a massive breakdown of the power grid and immense security and economic losses,necessitates an examination of the attack principle of power CPS,forecasting potential attack behaviors,and devising reasonable defensive strategies to counter network attacks.To solve the above issues,the following specific work is carried out in this paper.Firstly,considering the structural and functional characteristics of power CPS,the network model of power CPS dependent network is established,and the coupling and interaction relationship between the information layer communication network and the physical layer power system is described.Based on the above model,the basic principle and main process of network attack on information physical system are discussed.The feasibility of the established power CPS dependent network model is verified by an example simulation.Then,the potential device vulnerabilities in the power CPS are studied in this paper,and the vulnerability availability of each networked device in the information network is discriminated using a vulnerability scanning system,and the exploitable attack paths in the system are generated accordingly.After that,the possible attack behavior of the attacker was analyzed with the help of Hidden Markov Model and the maximum possible attack path was selected.After the attack,an integrated information-physical loss calculation model was established by considering the information layer communication traffic characteristics and the physical layer load loss.Finally,it is verified through simulation that the integrated loss is used to quantify the degree of impact suffered by the power CPS after the attack,which provides the basis for the defense work.Finally,this paper abstracts the power CPS attack and defense process as a game process between the attacking and defending parties,and establishes a two-player zero-sum game model with the result of information-physical integrated loss calculation as the game gain of both parties.The Minimax-Q algorithm is then employed to ascertain the most advantageous immediate gain and pick the most suitable defense strategy,extending the two-player zero-sum game process into a multi-stage game by taking into account the alteration of both sides’ tactics and the alteration of the system state.Finally,through simulation,the offensive and defensive game processes are simulated and the effectiveness of the selected defense strategy is verified.