A Robust Hybrid Islanding Detection Scheme for Distributed Generation Systems Based on PCC Voltage and Active Power Dynamics

Abstract

The increasing penetration of distributed generation (DG) in power distribution networks has significantly improved system reliability, energy efficiency, and the integration of renewable energy resources. However, this advancement also introduces critical technical challenges, among which islanding is considered one of the most serious concerns. Islanding occurs when a section of the network continues to be powered by DG units after disconnection from the main grid, potentially endangering personnel safety, compromising system stability, and damaging equipment. To mitigate these risks, international standards require fast and reliable islanding detection methods. Nevertheless, many conventional techniques suffer from large non-detection zones (NDZs), which limit their effectiveness under certain operating conditions. In this paper, a novel islanding detection method is proposed based on the combined analysis of voltage magnitude variations, their dynamic behavior, and active power fluctuations at the point of common coupling (PCC) in a smart grid environment. The proposed approach enhances detection speed and accuracy while significantly reducing the NDZ. Simulation results demonstrate the effectiveness of the method and confirm its superior performance compared to conventional techniques, making it a reliable solution for protecting both DG units and distribution networks.