Power-Response Matrix-Based Modeling of Converter Systems for Small-Signal Analysis

In this paper, a novel small-signal modeling approach for grid-connected converter systems is presented. The approach is based on the converter system’s power-response matrix, which correlates variations in grid voltage magnitude and frequency with variations in the exchanged active and reactive powers from the converter system. This formulation is useful not only for small-signal stability analysis of interconnected systems but also for directly assessing the grid services offered by converter systems, such as their contributions to total system inertia and damping. The paper provides a detailed analytical derivation of the converter system’s power-response matrix, along with an analysis of the small-signal stability of the interconnected system. Furthermore, a comparison between the proposed power-response matrix-based model and the more conventional impedance-based model is presented, establishing the equivalence between the two modeling approaches and highlighting the advantages of the proposed approach.