Implementation of anti-islanding scheme for a grid connected inverter

Abstract

As more PV systems join the utility grid the concern of undetected islanding operation increases. This concern is due to the safety hazards this phenomenon imposes on personnel and equipment. This paper discusses there different islanding schemes used and their features. As AFD method is the most popular method of islanding detection this paper proposes an improved method, where it uses AFD scheme for islanding detection but keeps the power quality high and the current THD less than 5%. Also the paper shows the effectiveness in detecting island in less than 2 s according to IEEE standards.