Comparative analysis of existing models for power-grid synchronization

TL;DR

This paper compares three models of power-grid synchronization, clarifies their assumptions within a unified framework, and provides tools for parameter estimation and analysis using real data and test systems.

Contribution

It offers a comprehensive comparison of leading synchronization models, deriving them from first principles and providing an open-source toolbox for practical analysis.

Findings

Models can be derived from a common generator-based framework

Heterogeneous network structures require non-identical oscillator modeling

Provided tools for parameter estimation from real power-grid data

Abstract

The dynamics of power-grid networks is becoming an increasingly active area of research within the physics and network science communities. The results from such studies are typically insightful and illustrative, but are often based on simplifying assumptions that can be either difficult to assess or not fully justified for realistic applications. Here we perform a comprehensive comparative analysis of three leading models recently used to study synchronization dynamics in power-grid networks -- a fundamental problem of practical significance given that frequency synchronization of all power generators in the same interconnection is a necessary condition for a power grid to operate. We show that each of these models can be derived from first principles within a common framework based on the classical model of a generator, thereby clarifying all assumptions involved. This framework allows us to view power grids as complex networks of coupled second-order phase oscillators with both forcing and damping terms. Using simple illustrative examples, test systems, and real power-grid datasets, we study the inherent frequencies of the oscillators as well as their coupling structure, comparing across the different models. We demonstrate, in particular, that if the network structure is not homogeneous, generators with identical parameters need to be modeled as non-identical oscillators in general. We also discuss an approach to estimate the required (dynamical) parameters that are unavailable in typical power-grid datasets, their use for computing the constants of each of the three models, and an open-source MATLAB toolbox that we provide for these computations.