Towards a 3-level blackout probabilistic risk assessment: Achievements and challenges

Although blackouts are infrequent, they result in major societal and economical negative consequences. These massive disruptions to electricity service are due to cascading outages, in which a lot of different phenomena occur. Even if a variety of methods are emerging to study cascading outages, it remains difficult to estimate the risk of blackout for a real grid and dangerous scenarios. Based on the analysis of past blackouts, a 3-level blackout probabilistic risk assessment can be developed in order to consider the main phenomena occurring in a cascading failure in a realistic way. But such an approach encounters several challenges and difficulties. The aim of this paper is to present such an approach, to assess present achievements and to discuss ways of solving future challenges.