The transient behavior of the Volt/Var control of photovoltaic systems for solar irradiation variations

Nowadays, photovoltaic (PV) systems supply reactive power in limited or planned situations with mutual agreements so that they can minimize an increase in over- and under-voltages. However, since PV systems depend on weather conditions, including solar irradiation, they have, in nature, intermittency in their output. Therefore, the objective of this study is to analyze the effect of ramp events of solar irradiation on the generation output of PV systems in the transient state. For this purpose, this study (a) models a distribution system that includes a PV system (e.g., a PV array, a DC bus and capacitor model, a controller, and a static generator) in DIgSILENT of Power Factory, (b) generates a ramp event of solar irradiation as input data to the PV system, and (c) examines the transient behavior of the PV system at the electromagnetic transient mode of DIgSILENT. Finally, the effect of reactive power control for the ramp event on over- and under-voltages will be addressed.