Long-range Response in AC Electricity Grids

TL;DR

This paper investigates how local topology changes in AC electricity grids can cause widespread effects, revealing a power-law decay of response with distance in both theoretical models and real-world grids.

Contribution

It extends previous studies from DC to AC grids by solving static load flow equations and analyzing long-range responses in real-world topologies.

Findings

Power-law decay of power flow change with distance in 2D grid models

Exponent of decay increases and saturates with system size

Long-range response observed in the German transmission grid

Abstract

Local changes in the topology of electricity grids can cause overloads far away from the disturbance, making the prediction of the robustness against changes in the topology - for example caused by power outages or grid extensions - a challenging task. The impact of single-line additions on the long-range response of DC electricity grids has recently been studied. By solving the real part of the static AC load flow equations, we conduct a similar investigation for AC grids. In a regular 2D grid graph with cyclic boundary conditions, we find a power law decay for the change of power flow as a function of distance to the disturbance over a wide range of distances. The power exponent increases and saturates for large system sizes. By applying the same analysis to the German transmission grid topology, we show that also in real-world topologies a long-ranged response can be found.