A comprehensive review of islanding detection methods

Abstract

Abstract With the integration of renewable energy resources into a distribution network, the power system is witnessing a drastic transformation. In comparison with conventional resources, the preference of renewable energy resources has a strong preference for the consumer end due to their availability and their positive influence on the environment. Despite their advantages, renewable resources bring some challenges to the distribution networks, where islanding is one of the critical issues in which the distributed generator continues to feed the network even after the utility grid is isolated from the distribution system. Planned islanding does not pose any risk to the maintenance personnel, but unplanned islanding does. Many research articles have been proposed to deal with the problem, for mitigating the issues related to islanding detection. This chapter presents a comprehensive review of different islanding detection methods available in the literature. Islanding detection methods can be broadly categorized as remote methods and local methods. The remote methods deal with the detection of islanding on the utility grid side that they rely on communication links/channels to disconnect the distributed generator; in contrast, the local methods deal with the islanding detection on the distributed generator side. The local methods are further classified as passive, active, hybrid, signal processing, and computational intelligence-based methods. In contrast to the passive methods that used the electrical parameters at the distributed generation (DG), the active methods intentionally inject small disturbance at the DG side to sense the disturbance and the hybrid methods are the combination of both passive and active methods. The passive methods are easy and more advantageous to implement due to their low cost and low power quality problems but are associated with larger nondetection zone and are vulnerable toward threshold setting. While the active methods have a very smaller nondetection zone, they are associated with power quality problems. To overcome these problems involved in islanding detection, signal processing and computational intelligence-based methods have been used, which have the capability of dealing with complex nonlinear systems. An insight into different methods based on various criteria such as detection time, nondetection zone, and detection accuracy is tabulated and summarized to assist the field engineers and researchers in establishing the suitability of the method for their own system. Lastly, the present status with a suggestion toward the future direction of research for islanding detection has also been presented.