Topological theory of resilience and failure spreading in flow networks

Link failures in supply networks can have catastrophic consequences that can lead to a complete collapse of the network. Strategies to prevent failure spreading are thus heavily sought after. Here, we make use of a spanning tree formulation of link failures in linear flow networks to analyze topological structures that prevent failure spreading. In particular, we exploit a result obtained for resistor networks based on the matrix tree theorem to analyze failure spreading after link failures in power grids. Using a spanning tree formulation of link failures, we analyze three strategies based on the network topology that allow us to reduce the impact of single link failures. All our strategies either do not reduce the grid's ability to transport flow or do in fact improve it—in contrast to traditional containment strategies based on lowering network connectivity. Our results also explain why certain connectivity features completely suppress any failure spreading as reported in recent publications.