SARA (Simulation-based Admittance Response Analysis): A MATLAB/Simulink Tool for AC/DC Admittance Measurement

SARA (Simulation-based Admittance Response Analysis) is a MATLAB/Simulink software tool for obtaining the frequency-domain characterisation of AC/DC small-signal admittance matrices of electrical devices directly from time-domain simulations. SARA performs automated frequency sweeping with controlled perturbation injections—positive-sequence, negative-sequence, and DC—and applies FFT-based phasor extraction to reconstruct AC-side, DC-side, and AC/DC coupling terms using a unified pn-sequence formulation. The tool is compatible with any Simulink-based electrical device, ranging from detailed white-box models to protected industrial black-box blocks.