Study and analysis of anti-islanding protection for grid-connected photovoltaic central of Ghardaia

Abstract

This paper aims at providing a simulation study of the nature of the Islanding phenomenon occurs in the Grid-Tied PV (photovoltaic) System and the different methods to detect it which permits us to protect the system. We are going to resort to a number of devices to put into practice these methods including over-current and undercurrent (OI/UI) relays, over-voltage and under-voltage (OV/UV) relays and over-frequency and under-frequency (OF/UF) relays. The protection is examined in two different circumstances, when the PV system is completely disconnected from the electric power grid and also during the occurrence of some various grid faults. These faults can lead to the decoupling of the inverter and cause of unintentional islanding phenomenon that has dangerous consequences particularly on equipment and on grid maintenance personnel.