Islanding detection technique based on inverse hyperbolic secant function

This study presents an inverse hyperbolic secant function based islanding detection technique for distribution network containing various types of distributed generations. The proposed scheme is based on rate of change of inverse hyperbolic secant function of negative sequence voltage signal. Different non-islanding events along with various islanding conditions have been simulated by modelling IEEE 34-bus system using PSCAD/EMTDC software package. The proposed scheme is able to detect islanding condition even with zero active and reactive power mismatches. Moreover, it eliminates non-detection zone completely and at the same time also remains stable during diversified non-islanding events including change in network topology. The simulation results indicate that the proposed scheme not only detects islanding condition rapidly, but also provides better stability in case of critical non-islanding events during which most of the existing schemes issue nuisance tripping. Furthermore, comparative evaluation of the proposed scheme with the recently proposed techniques in the literature clearly indicates superiority of the proposed scheme. At the end, issues related to practical implementation of the proposed scheme have also been discussed.