A simple technique for islanding detection with negligible non-detection zone

Although active islanding detection techniques have smaller non-detection zones than passive techniques, active methods could degrade the system power quality and are not as simple and easy to implement as passive methods. The islanding detection strategy, proposed in this paper, combines the advantages of both active and passive islanding detection methods. The Distributed Generation (DG) interface was designed so that the DG maintains stable operation while grid connected and loses its stability once islanded. Thus, the over/under voltage and over under frequency protection method would be sufficient to detect islanding. The main advantage of the proposed technique is that it relies on a simple approach for islanding detection and has negligible non-detection zone. The system was simulated on PSCAD/EMTDC and simulation results are presented to highlight the effectiveness of the proposed technique.