Distance protection and fault location of the PV power plants distribution lines

Unlike the synchronous generators, the short-circuit current provided by the photovoltaic (PV) sources is limited by the grid-connected inverters and closely related to the normal conditions, which impacts the protection of the power systems. This study deals with the protection of the power lines (distribution feeders) that connect the PV power plants (PVPP) to the grid; the first part of this study analyses the impact of the grid-connected PV (GCPV) system on the conventional distance protection. A specific coordination between the over-current protection of the grid side and the distance protection of the PVPP side was used to eliminate this impact. This coordination requires delaying the distance protection and keeping the inverter connected to the grid, which was achieved by fault ride-through (FRT) feature accompanied with the inverter control during the fault condition. The second part studies the possibility of using the double-end-impedance-based fault location on the PVPP power lines, and some FRT strategies were suggested to reduce the effect of the inverter control loops on obtaining the accurate fault location. The proposed work was verified by GCPV system model using MATLAB/Simulink software