Abstract

As more distributed generators, such as solar panels, wind turbines, and micro-hydro plants, are added to power networks, these systems are becoming more decentralized and resilient. Although this change improves grid efficiency and sustainability, it also brings new challenges, such as the risk of unintentional islanding. Islanding occurs when a part of the grid powered by distributed generators becomes separated from the main utility, which can create safety and equipment risks. To address this, our study introduces a secure hybrid islanding detection method that combines passive and active detection techniques. The method uses two passive indicators–the rate of change of active power (dp/dt) and reactive power (dq/dt) along with an active load-connecting strategy. The passive indicators continuously monitor the system, whereas the active method confirms islanding by making controlled changes. We tested this method on an 11-Kv distribution feeder model from the Jumla District, using both synchronous and inverter-based distributed generators. MATLAB/Simulink simulations in different scenarios showed that the method detected islanding quickly and accurately, with response times under the 2-s international standard and strong resistance to false alarms. These results suggest that our method is effective and reliable, helping to make power systems with distributed generators safer and more robust.