Assessing security of power and ICT systems via a risk-based approach within an integrated framework

The increasing vulnerability of modern power systems to both natural and man-related threats, as well as their increasing dependency on ICT systems makes it convenient to adopt integrated approaches for security assessment and control. Moreover, the need to analyse extreme, low-probability events (from which many blackouts originated in the past) calls for the adoption of the risk concept to perform more in-depth security analyses. The present paper describes a probabilistic risk-based methodology, developed within the EU research project called AFTER, aimed to perform risk assessment (including hazard, vulnerability and impact analysis) of the integrated electrical power and ICT systems. The paper focuses on the steps to build the assessment framework (threats/vulnerabilities identification and classification, contingency modeling, power system response modeling and computation of risk indicators for operation and planning purposes).