Open AccessIslanding detection scheme for converter‐based DGs with nearly zero non‐detectable zone
Author(s) -
Gupta Om Hari,
Tripathy Manoj,
Sood Vijay K.
Publication year - 2019
Publication title -
iet generation, transmission and distribution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.92
H-Index - 110
eISSN - 1751-8695
pISSN - 1751-8687
DOI - 10.1049/iet-gtd.2018.5168
Subject(s) - islanding , microgrid , control theory (sociology) , robustness (evolution) , fault (geology) , voltage , fault detection and isolation , electrical impedance , computer science , matlab , transient (computer programming) , distributed generation , electronic engineering , engineering , electrical engineering , control (management) , artificial intelligence , biochemistry , chemistry , seismology , renewable energy , geology , actuator , gene , operating system
This study presents a new method for detecting an islanding event in a microgrid with embedded converter‐based distributed generation (DG). Unlike other schemes, the proposed scheme injects negligible perturbations into the microgrid after the generation of an alert signal. The proposed scheme then uses another index called superimposed impedance, Δ Z . The Δ Z is characterised by a low steady‐state magnitude during the grid‐connected mode and a high magnitude during the islanded mode. Furthermore, for a fault at the point of common coupling (PCC), the magnitudes of Δ Z and PCC voltage are both very low – except during the initial transient period, where |Δ Z | momentarily crosses the threshold. Therefore, an islanding event can be detected if the magnitude of Δ Z is high for some specified time. Moreover, a fault event will not be misdirected as an islanding event because the steady‐state magnitudes of both the Δ Z and PCC voltage are very low in the case of a fault. The robustness of the proposed detection scheme is evaluated against different islanding conditions and also, for a fault at the PCC, first by using MATLAB‐based simulations and later by using a laboratory‐based experimental setup. A comparison with a recently published detection scheme shows the superiority of the proposed schemes.