Short Circuit Current Contribution of a Photovoltaic Power Plant

The grid integration of renewable energies is more and more influencing the short circuit capacity (SCC) of power systems all over the world. The behavior of renewable energy sources, e.g. wind or solar energy, is different from that of classical synchronous generators during symmetrical or unsymmetrical short circuits. The response of renewable energy generation units to short circuits is more or less controllable by the power electronics used in the converter system and the corresponding control algorithms. These differences have to be taken into account during planning grid extensions by the power system operator and designing protective or security functions for the network and its components.In this paper the authors describe the short circuit current contribution of a photovoltaic power plant. For a 3 MW photovoltaic system equipped with several generation units and connected to a medium voltage power system, three different short circuit scenarios (single-line-to-ground, line-to-line and three-phase faults) and the corresponding short circuit current contribution of the power plant were calculated and the results illustrated and discussed.