Comparing the Topological and Electrical Structure of the North American Electric Power Infrastructure

TL;DR

This paper analyzes the North American electric power infrastructure by comparing its topological and electrical structures, revealing significant differences from common network models and proposing a new electrical distance-based representation.

Contribution

It introduces a novel method for representing electrical connectivity using electrical distances and compares topological and electrical structures of power grids.

Findings

Power grids differ from random, preferential-attachment, and small-world models in key network metrics.

Electrical and topological structures of power networks show notable differences.

Traditional topological models may be misleading for power system analysis.

Abstract

The topological (graph) structure of complex networks often provides valuable information about the performance and vulnerability of the network. However, there are multiple ways to represent a given network as a graph. Electric power transmission and distribution networks have a topological structure that is straightforward to represent and analyze as a graph. However, simple graph models neglect the comprehensive connections between components that result from Ohm's and Kirchhoff's laws. This paper describes the structure of the three North American electric power interconnections, from the perspective of both topological and electrical connectivity. We compare the simple topology of these networks with that of random (Erdos and Renyi, 1959), preferential-attachment (Barabasi and Albert, 1999) and small-world (Watts and Strogatz, 1998) networks of equivalent sizes and find that power grids differ substantially from these abstract models in degree distribution, clustering, diameter and assortativity, and thus conclude that these topological forms may be misleading as models of power systems. To study the electrical connectivity of power systems, we propose a new method for representing electrical structure using electrical distances rather than geographic connections. Comparisons of these two representations of the North American power networks reveal notable differences between the electrical and topological structure of electric power networks.