Abstract
We use observed transmission line outage data to make a Markovian influence graph that describes the probabili- ties of transitions between generations of cascading line outages. Each generation of a cascade consists of a single line outage or multiple line outages. The new influence graph defines a Markov chain and generalizes previous influence graphs by including multiple line outages as Markov chain states. The generalized influence graph can reproduce the distribution of cascade size in the utility data. In particular, it can estimate the probabilities of small, medium and large cascades. The influence graph has the key advantage of allowing the effect of mitigations to be analyzed and readily tested, which is not available from the observed data. We exploit the asymptotic properties of the Markov chain to find the lines most involved in large cascades and show how upgrades to these critical lines can reduce the probability of large cascades.
Highlights
Cascading outages in power transmission systems can cause widespread blackouts
We demonstrate using the Markov chain to quantify the impact of mitigation by upgrading the ten lines critical for large cascades identified in section V-A with r = 80%
Successive line outages, or, more precisely, successive sets of near simultaneous line outages in the cascading data correspond to transitions between nodes of the influence graph and transitions in the Markov chain
Summary
Cascading outages in power transmission systems can cause widespread blackouts. These large blackouts are infrequent, but are high-impact events that occur often enough to pose a substantial risk to society [1], [2]. There are two main approaches to evaluating cascading risk: simulation and analyzing historical utility data. Historical outage data can be used to estimate blackout risk [2] and detailed outage data can be used to identify critical lines [7]. We process historical line outage data to form a Markovian. The Markovian influence graph can quantify the probability of different sizes of cascades, identify critical lines and interactions, and assess the impact of mitigation on the probability of different sizes of cascades
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
