SIaD-Tool: A Comprehensive Frequency-Domain Tool for Small-Signal Stability and Interaction Assessment in Modern Power Systems

TL;DR

SIaD-Tool is an open-source frequency-domain analysis software that assesses small-signal stability and interactions in modern power systems using innovative perturbation schemes and multiple stability evaluation methods.

Contribution

It introduces a novel perturbation scheme for direct scanning in the target frame and integrates multiple automated stability assessment techniques in a multi-platform tool.

Findings

High accuracy in detecting critical modes and interaction frequencies

Scalability demonstrated on large power system models

Robustness confirmed across various case studies

Abstract

This paper presents SIaD-Tool, an open-source frequency-domain (FD) scanning solution for stability and interaction assessment in modern power systems. The tool enables multi-sequence identification in the abc, dq0, and 0pn frames and supports both series voltage and parallel current perturbation strategies. A novel perturbation scheme allows direct scanning in the target frame, simplifying the analysis of coupling effects and mirrored frequencies. SIaD-Tool is implemented on a multi-platform architecture, including MATLAB/Simulink and Python-PSCAD/EMTDC. Beyond system identification, it integrates automated stability evaluation through four standardized methods: Generalized Nyquist Criterion (GNC), modal impedance analysis, phase margin assessment, and passivity checks. Validation is carried out via extensive case studies involving passive elements, grid-following and grid-forming converters, offshore wind power plants, and the IEEE 9-bus system. Results confirm high accuracy, scalability, and robustness in detecting critical modes, interaction frequencies, oscillatory behavior, and stability margins.