Learning the Frequency Dynamics of the Power System Using Higher-order Dynamic Mode Decomposition

TL;DR

This paper introduces a data-driven higher-order dynamic mode decomposition method to accurately model power system frequency dynamics, capturing nonlinear behaviors and complex oscillations better than linear models, validated on standard test systems.

Contribution

It presents a novel HODMD approach for learning power system frequency dynamics that requires no prior knowledge and effectively captures nonlinear and high-dimensional behaviors.

Findings

HODMD outperforms linear models in predicting frequency oscillations.

The method successfully captures system-wide spatio-temporal modes.

Validation on IEEE 14-bus and WECC systems confirms robustness.

Abstract

The increasing penetration of renewable energy sources, characterised by low inertia and intermittent disturbances, presents substantial challenges to power system stability. As critical indicators of system stability, frequency dynamics and associated oscillatory phenomena have attracted significant research attention. While existing studies predominantly employ linearized models, our findings demonstrate that linear approximations exhibit considerable errors when predicting frequency oscillation dynamics across multiple time scales, thus necessitating the incorporation of nonlinear characteristics. This paper proposes a data-driven approach based on higher-order dynamical mode decomposition (HODMD) for learning frequency dynamics. The proposed method offers distinct advantages over alternative nonlinear methods, including no prior knowledge required, adaptability to high-dimensional systems, and robust performance. Furthermore, HODMD demonstrates superior capability in capturing system-wide spatio-temporal modes, successfully identifying modal behaviour that remains undetectable through standard Dynamic Mode Decomposition techniques. The efficacy of the proposed methodology is validated through comprehensive case studies on both IEEE 14-bus and WECC systems.