Impact Of Cyber Attack On Power System Reliability And Its Consequence Evaluation

With the development of information technology,the power system has gradually become a complex and large system that integrates power and information networks.The supervisory control and data acquisition(SCADA)system as an important information system of power system,while enhancing the observability and controllability of the power system,is also a high-value target for cyber attack,which may cause potential security risks and economic losses in the power system.Due to the complexity of the information system and the power system itself,and the different abilities or intentions of attackers and other reasons,the impact of cyber attack on power system reliability and the evaluation of its consequences become a difficult problem,the theoretical basis and system model need to be further improved.In this paper,based on the existing cyber attack modeling methods and power system reliability assessment methods,a comprehensive model of cyber attack and power system reliability is established.Firstly,the architecture of SCADA system and its existing vulnerability are analyzed,and the SCADA-oriented cyber attack classification is summarized.Secondly,the attack tree model based on fuzzy analytic hierarchy process is used to simulate cyber attack process and the success probability of each attack path can be obtained.In addition,on the basis of analyzing how the cyber attack affects the reliability of the power system,this paper establishes the power system reliability model considering the direct action type cyber attack and the power system reliability model with the indirect action type cyber attack:the former establishes a revised forced outage rate model of the circuit breaker,using non-sequential Monte Carlo method to calculate power system reliability index,and the latter establishes a minimum power outage calculation model that considers the controllability of the nodes,combining node attack success probability to calculate power system reliability index;Finally,using IEEE-RTS79 system and IEEE-9 nodes system as examples,the effects of circuit breaker faultless tripping attack and distributed denial of service attack on the reliability of power system are studied respectively,and the feasibility and effectiveness of the proposed method are verified.