A Distributed Scheme for Stability Assessment in Large-Scale Structure-Preserving Models via Singular Perturbation

TL;DR

This paper introduces a distributed, computationally efficient stability assessment method for large power systems, leveraging singular perturbation analysis to relate system parameters to stability without extensive computation.

Contribution

It develops a novel stability certificate based on singular perturbation techniques, enabling distributed assessment using local measurements in large-scale power systems.

Findings

The method is fully distributed and scalable to large systems.

Numerical tests on WSCC system validate effectiveness.

The certificate provides insights into the impact of system parameters on stability.

Abstract

Assessing small-signal stability of power systems composed of thousands of interacting generators is a computationally challenging task. To reduce the computational burden, this paper introduces a novel condition to assess and certify small-signal stability. Using this certificate, we can see the impact of network topology and system parameters (generators' damping and inertia) on the eigenvalues of the system. The proposed certificate is derived from rigorous analysis of the classical structure-preserving swing equation model and has a physically insightful interpretation related to the generators' parameters and reactive power. To develop the certificate, we use singular perturbation techniques, and in the process, we establish the relationship between the structure-preserving model and its singular perturbation counterpart. As the proposed method is fully distributed and uses only local measurements, its computational cost does not increase with the size of the system. The effectiveness of the scheme is numerically illustrated on the WSCC system.