Evaluation of Countermeasures against Voltage Flicker in Photovoltaic Inverters

Renewable energy has been increasingly integrated into grids and plays a significant role in ensuring a stable electricity supply. Voltage flicker (VF) is typically observed in the power flow from photovoltaic (PV) generators. In this study, we focus on the VF caused by the injection of reactive power flow from the islanding detection function of PVs. To stabilize the VF in a short period, several countermeasures for reducing the VF risk from the utility side have been proposed; these include network loop operation on distribution lines and the addition of temporary components, such as static capacitors and static synchronous compensators. However, such countermeasures are generally implemented simultaneously and are not individually quantified. In this study, we evaluate and quantify the efficiency of each countermeasure in VF reduction using numerical simulations of actual middle- and low-voltage network models. Furthermore, we focus on reducing the VF risk caused by PVs.