Analytical formulation for the nondetection zones of inverter-based distributed generators with grid support functions

This paper proposes a new formulation for computing the nondetection zones (NDZs) of passive anti-islanding protection for inverter-based distributed generators (IBDGs) operating with P ( f ), Q ( V ) and P ( V ) grid support functions (GSFs). The proposed method is based on straightforward calculations of the post-islanding frequency and voltage values, followed by an analysis of the anti-islanding protection thresholds. The formulation considers the influence of the IBDGs’ current limitation, as it changes the voltage signal after islanding and, consequently, the NDZ limits. Validation is performed through electromagnetic transient (EMT) simulations in ATP for a test system based on IEEE Std. 1547.1–2020 and the IEEE 34-nodes electrical system. The results demonstrate high precision, with NDZs and steady-state frequency/voltage estimations closely matching the EMT simulations, even when different parameters for the GSFs are employed. Additionally, to the best of the authors’ knowledge, the NDZ formulation with IBDG operating with the P ( V ) GSF has not been presented in the literature so far. Finally, the comparative analysis demonstrated the superiority of the proposed formulation over other approaches.