Assessment of Cyber Resilience Indices of Information Collection and Processing Systems in Electric Power Systems Based on Semi-Markov Models

Purpose of the study: The study aims to design an algorithm for determining the cyber resilience indices of information collection, transmission, and processing systems (SCADA, WAMS) to control electric power systems. This algorithm makes it possible to factor in possible states and measures to restore such systems when cyber resilience is lost. Research methods include the probability theory, methods of power system reliability analysis, and Markov methods. Result of the research: The analysis of the reliability of WAMS, which is necessary for assessing the cyber resilience of the EPS, has been carried out. A cyber resilience model is proposed, on the basis of which an algorithm for determining the cyber resilience index of SCADA, WAMS systems with a low quality of measurement information used in EPS control has been developed. To take into account possible states of SCADA, WAMS systems and measures for their restoration (detection, mitigation and response) in case of violation of cyber resilience, the algorithm uses the tools of probability theory and Markov methods. The effectiveness of the application of the developed algorithm is confirmed by the example of calculating the WAMS cyber resilience index with a low quality of PMU data. The results obtained can be useful in making decisions on the formation of control actions on the EPS to ensure its cybersecurity in the context of cyber-attacks on information collection, transmission, and processing systems.