Power System Reliability Assessment Incorporating Cyber Attacks Against Wind Farm Energy Management Systems

By exploiting the vulnerabilities in cyber components, an attacker could intrude in the wind farm supervisory control and data acquisition (SCADA) system and energy management system (EMS), and maliciously trip one or multiple wind turbines. The reliability of the overall power system could thus be impacted by the performance of wind farms. In this paper, cyber attack scenarios concerning cyber components or networks are considered in the integrated wind farm SCADA/EMS system architecture. Two Bayesian attack graph models are adopted to represent the procedures of successful cyber attacks, and a mean time-to-compromise model is used by considering different attack levels and various vulnerabilities. Frequencies of successful cyber attacks on the wind farm SCADA/EMS system are estimated. A procedure for evaluating the power system reliability is proposed by considering wind turbine trips caused by various cyber attacks. Simulations are conducted based on a typical IEEE reliability test system. Simulation results indicate that the overall system reliability decreases when the frequency of successful attacks on the wind farm SCADA/EMS system and skill levels of attackers increase.