A Review of Islanding Detection in Microgrids

Abstract

The increasing integration of Distributed Energy Resources (DER) such as solar photovoltaics, wind turbines, and energy storage systems into modern power systems has led to the rapid evolution of microgrids. Microgrids offer numerous benefits, including improved energy resilience, reduced transmission losses, and the facilitation of renewable energy adoption. One of the critical challenges associated with microgrid operation is the phenomenon of islanding—a condition in which a microgrid or a portion of the power system continues to operate in isolation from the main utility grid after a disturbance, such as a fault or maintenance-induced disconnection. This review paper provides a comprehensive examination of existing islanding detection methods, broadly categorizing them into passive, active, hybrid, and communication-based approaches. We present these methods in terms of detection speed, accuracy, Non-Detection Zones (NDZ), impact on power quality, and compatibility with various DER technologies. By consolidating and evaluating the current landscape of islanding detection strategies, this review aims to guide researchers and system designers in selecting or developing appropriate detection mechanisms for reliable microgrid operation in both grid-connected and islanded modes.