Impact of photovoltaic systems on voltage magnitude and unbalance in low voltage networks

The penetration of photovoltaic distributed generation (PVDG) in low voltage (LV) distribution networks has been growing over the past years in Brazil. A major issue concerning the PVDG penetration in LV grids is the excessive voltage rise and voltage unbalance. Thus, this paper analyzes the impact on voltage of PVDG penetration in LV networks considering a common unbalanced connection of the generators. A real distribution network was modeled in OpenDSS, including smart meter data and a realistic estimation of PVDG, to perform the simulations. Although there are benefits provided by DG penetration, results show that the problem of voltage rise is intensified due the unbalanced connection of the generation, which is generally overlooked by utilities. The study proposed in this paper shows the relevance for utilities to improve the LV management and analysis to deal with the increasing level of micro PV generation in Brazil.