Improved constant current islanding detection with regardless NDZ and its stability analysis

Distributed Generations (DGs) much have obtained attentions to be used in practical systems while protection issues against islanding phenomenon needs to be taken into the account. This paper introduces also analysis controlling feedback in order to construct reference current in constant current islanding detection to find out islanding phenomenon for inverter-based DGs. In this paper, d-axis reference current has been functionalized respecting PCC voltage and then designed in order to highly mitigate none detection zone (NDZ). At first the validity of the proposed strategy mathematically was analyzed from power and stability point of view, then under real power system situation (i.e. multiple DG case, load switching, voltage sags and swells). The simulation results were carried out through MATLAB/Simulink environment proved performance of this easy-to-implement islanding detection method.