Performance of large-scale grid-connected photovoltaic system under various fault conditions

The paper discusses the performance of a 10 MVA grid-connected photovoltaic system (GCPS) under various grid faults. The faults include the typical three-phase symmetrical fault (3LG), the single-phase to-ground fault (LG), two-phases-to-ground fault (2LG) and the phase-to-phase fault (2L). The system is studied with and without reactive power support in the case of voltage sags. The faults that may lead to the inverter protection triggering from both DC and AC sides are identified based on grid codes, fault-ride-through (FRT) capability and according to the datasheet of the inverter. The evaluation is performed through electromagnetic transients (EMT) simulations using DigSILENT PowerFactory software. The results indicate that the reactive power injection in asymmetrical faults triggers inverter protection systems apart from the AC over-current protection.