COMPUTER MODELING AND SIMULATION OF OVER CURRENT RELAY SETTINGS FOR SOLAR POWER PLANT

In the last decade, there has been a significant increase in the number of photovoltaic power plants connected to the distribution network, due to factors such as environmental concerns, grid support, standby capacity, efficiency, security and reliability. This paper presents a simulation procedure of overcurrent phase and overcurrent ground fault relay protection coordination for a PV power plant connected to the distribution network. Computer simulation programs are very useful tools for studying PV systems protection coordination. In this paper, EasyPower computer program is used with the module Power Protector. Time-current relay curves are simulated and plotted for important protection devices in the network and the PV power plant. The fault analysis is performed on several places in the network and the PV power plant and the transformer station. Three phase and single phase to ground faults were considered. Time-current plots were presented and a relay setting is proposed and confirmed in order to satisfy selectivity and backup protection.