Line Failure Localization of Power Networks Part II: Cut Set Outages

TL;DR

This paper analyzes how cut set outages propagate in power networks, providing a criterion to predict failure patterns and demonstrating their impact on the entire network through theoretical and empirical analysis.

Contribution

It introduces a Simple Path Criterion for understanding failure propagation due to cut set outages and extends the analysis to general cut set failures in power systems.

Findings

Propagation patterns are determined by load balancing bus positions.

Cut set outages impact the entire network, affecting all remaining lines.

Analytical results are validated on IEEE 118-bus system with AC power flow.

Abstract

Transmission line failure in power systems prop-agate non-locally, making the control of the resulting outages extremely difficult. In Part II of this paper, we continue the study of line failure localizability in transmission networks and characterize the impact of cut set outages. We establish a Simple Path Criterion, showing that the propagation pattern due to bridge outages, a special case of cut set failures, are fully determined by the positions in the network of the buses that participate in load balancing. We then extend our results to general cut set outages. In contrast to non-cut outages discussed in Part I whose subsequent line failures are contained within the original blocks, cut set outages typically impact the whole network, affecting the power flows on all remaining lines. We corroborate our analytical results in both parts using the IEEE 118-bus test system, in which the failure propagation patterns exhibit a clear block-diagonal structure predicted by our theory, even when using full AC power flow equations.