Islanding Detection and Transition between Grid Connected and Standalone Mode of a PV Plant

An islanding detection and transition between grid connected (GC) and standalone (SA) mode of a photovoltaic (PV) plant is presented. A passive method of islanding detection method is used which senses the voltage, frequency and phase for the detection of islanding. A modified synchronous reference frame (SRF) controller is used in this paper which provides a smooth transition between grid-connected and islanded modes of operation. In order to improve the reliability of the power supply an energy storage device (battery) is used during islanding mode. The effectiveness of the proposed system which is operating in both GC and SA modes is verified using MATLAB simulink.