Decentralized Stability of IBR-dominated Power Grids Using Block Diagonal Dominance
For power grid operators integrating inverter-based resources, this offers a scalable, decentralized stability assessment method that is less conservative than existing approaches.
This paper develops a block diagonal dominance (BDD) criterion for decentralized small-signal stability in IBR-dominated power grids, showing it is much less conservative than strict diagonal dominance while ensuring a minimum decay rate for oscillations. The approach provides a practical, model-agnostic stability certificate without restrictive assumptions.
The growing penetration of inverter-based resources (IBRs) necessitates stability assessment methods that are scalable, decentralized, and model-agnostic. This paper develops a block diagonal dominance (BDD) criterion for decentralized small-signal stability of IBR-dominated power grids. The proposed approach forms the basis for an enhanced IBR connection compliance condition from a small-signal stability perspective that can be evaluated locally for IBRs to be connected to the grid. The proposed approach is shown to be much less conservative than strict diagonal dominance (SDD). Beyond mere stability, we ensure a minimum decay rate or maximum settling time for IBR-induced oscillation. Crucially, these are achieved without imposing restrictive assumptions on network or IBR models. The framework therefore, offers a practical and theoretically grounded basis for decentralized stability certificate of IBR-dominated power grids.