Advanced Active Islanding Method With Recursive Least Square for Microgrid

Abstract

Islanding is one of the challenging task for microgrid system. There are various types of islanding methods. Local methods also classified as passive, active, and hybrid methods. Passive islanding methods are easy to execute, cheaper for multi-distributed generation (DG) system but have large nondetection zone (NDZ). A very few active and hybrid methods were tested on multi-DG system till now. In this article, a new method is proposed for DGs connected in parallel considering a recursive least square (RLS) algorithm at point of common coupling for islanding. There are various parameters like voltage, current, frequency, impedance, harmonics, etc., used to detect the islanding. Here a frequency of active frequency drift (AFD) current with RLS is considered as a variable parameter. Further comparative analysis was done between conventional active and passive methods with the proposed method. In the proposed method, a variation of estimated frequency signal generates the tripping signal in fast manner as compare to other methods. The simulation results are analyzed based on MATLAB software and verified the same by implementing prototype hardware experimental setup. The analysis shows that the estimation of frequency for current of AFD with RLS approach is more suitable for islanding during zero power mismatch condition.