Towards quantifying cascading blackout risk

Blackouts become widespread by initial failures propa- gating in a diverse and intricate cascade of rare events. We describe this complicated cascade using a bulk probabilistic model in which the initial failures propagate randomly ac- cording to a branching process. The branching process pa- rameters can be statistically estimated from observed data or simulations and then used to efficiently predict the prob- ability distribution of blackout size. We review the cur- rent testing of these methods on simulations and observed data and discuss the next steps towards achieving verified and practical methods for quantifying cascading failure of electric power systems. The ability to efficiently quantify cascading blackout risk from observed data and simulations could offer new ways to monitor power transmission system reliability and quantify the reliability benefit of proposed improvements.