Optimal Decomposition of Utility Outage Sequence for Cascading Failure Interaction Estimation

Estimated component failure interactions from utility outage data can capture the general failure propagation patterns and help identify key components of a power system. Conventionally, utility outages are grouped into cascades and generations according to inter-outage time based on arbitrarily chosen thresholds. In this paper, we propose an optimal decomposition approach for utility outage data. By approximating the temporal pattern of the outage sequence by a Poisson process, an adaptive generation duration threshold is calculated to group the generations for each cascade. Compared to the conventional method, the proposed method can reveal more failure interactions and mitigate heterogeneity. The results based on real utility outage data demonstrate the effectiveness of the proposed optimal decomposition approach.