Uncovering the inherited vulnerability of electric distribution networks

TL;DR

This study investigates the inherent vulnerabilities of evolving medium-voltage distribution networks by analyzing their topological properties and resilience over time, revealing stable structural weaknesses despite network growth.

Contribution

It provides new insights into the structural vulnerabilities of distribution networks and confirms that their inherent weaknesses persist during evolution, based on historical network analysis.

Findings

Network tolerance remained stable over time.

Distribution network vulnerabilities are linked to structural properties.

Evolutionary growth does not significantly alter inherent weaknesses.

Abstract

Research on the vulnerability of electric networks with a complex network approach has produced significant results in the last decade, especially for transmission networks. These studies have shown that there are causal relations between certain structural properties of networks and their vulnerabilities, leading to an inherent weakness. The purpose of present work was twofold: to test the hypotheses already examined on evolving transmission networks and to gain a deeper understanding on the nature of these inherent weaknesses. For this, historical models of a medium-voltage distribution network supply area were reconstructed and analysed. Topological efficiency of the networks was calculated against node and edge removals of different proportions. We found that the tolerance of the evolving grid remained practically unchanged during the examined period, implying that the increase in size is dominantly caused by the connection of geographically and spatially constrained supply areas and not by an evolutionary process. We also show that probability density functions of centrality metrics, typically connected to vulnerability, show only minor variation during the early evolution of the examined distribution network, and in many cases resemble the properties of the modern days.