Islanding Detection Method of a Photovoltaic Installation Destined to Power a RLC Load and Integrated to LV Network

Abstract

The islanding of grid-connected photovoltaic (PV) installations is a difficult problem that leads to many protection and security problems. A variety of islanding detection methods (IDMs) are proposed in several studies and these techniques are categorized into passive, active and communication based methods. This study describes the IDM adopted to detect islanding situation in the new PV installation connected to LVs grid of OCP Group (Cherifian Office for Phosphates in Morocco), global leader in the phosphate and phosphate derivatives markets. After having defined the way in which the PV generators will be integrated within the OCP Group grid, the causes that could lead to islanding situation are established. The comparison on the most used methods for islanding detection in the grid connected photovoltaic system (PV) is based on three parameters: the Non-Detection Zone (NDZ), the Detection Duration Time (DDT) and Total Harmonic Distortion (THD) of each method. These performance criteria are compared with the limit thresholds authorized by the IEEE 1574 standard, which are 5% for THD and 2 seconds for DDT. The Slip Mode Frequency Shift (SMS) method is demonstrated to be the most effective, for our installation, among the simulated methods, with THD and DDT of 1.3% and 0.28s, respectively.