Harmonics-Based Enhanced Passive Islanding Method for Grid-Connected System

Abstract

Now a day, distributed sources are emerging widely due to their advantages owing to renewable-based power generation. In this paper, a novel passive islanding method for the inverter-based grid-connected system is presented. This method can be suitably applied along with the conventional passive methods like under/over voltage and under/over frequency islanding techniques. Total harmonic distortion (THD) at the point of common coupling (PCC) is used to discriminate the islanding condition, and to safely disconnect the grid. This method has an advantage that it is able to discriminate non-detection zone (NDZ) when the local load matches the inverter output power. The results using MATLAB simulations and laboratory prototype have been presented.