Heterogeneity effects in power-grid network models

TL;DR

This study compares phase synchronization in power-grid and lattice models, revealing finite size effects, hysteresis, and avalanche dynamics, with implications for understanding stability and disorder in real power networks.

Contribution

It demonstrates that power-grid networks exhibit first-order synchronization transitions with no true phase transition in the thermodynamic limit, highlighting the effects of network heterogeneity.

Findings

Synchronization transitions are of first order with hysteresis.

No true phase transition in the thermodynamic limit for power grids.

Avalanche durations follow power-law distributions, indicating rare region effects.

Abstract

We have compared the phase synchronization transition of the second order Kuramoto model on 2D lattices and on large, synthetic power grid networks, generated from real data. The latter are weighted, hierarchical modular networks. Due to the inertia the synchronization transitions are of first order type, characterized by fast relaxation and hysteresis by varying the global coupling parameter K. Finite size scaling analysis shows that there is no real phase transition in the thermodynamic limit, unlike in the mean-field model. The order parameter and its fluctuations depend on the network size without any real singular behavior. In case of power grids the phase synchronization breaks down at lower global couplings, than in case of 2D lattices of the same sizes, but the hysteresis is much narrower or negligible due to the low connectivity of the graphs. The temporal behavior of de-synchronization avalanches after a sudden quench to low K values, has been followed and duration distributions with power-law tails have been detected. This suggests rare region effects, caused by frozen disorder, resulting in heavy tailed distributions, even without a self organization mechanism as a consequence of a catastrophic drop event in the couplings.