Operation of a Low Voltage Distribution Grid in Cyprus and the Impact of Photovoltaics and Electric Vehicles

The operation of a typical 4-wire, radial, Low Voltage Distribution Grid (LVDG) in the Cyprus power system, where the neutral conductor is grounded only at the MV/LV transformer, is investigated under different scenarios. These include seasonal loading profiles and different penetration levels of photovoltaics (PVs) and electric vehicles (EVs). The analysis is focused on the impact of PVs and EVs on the voltage profile of the LVDG, the loading conditions of the distribution lines/cables and on the system losses. The results indicate that even with a moderate number of PVs, the admissible voltage limits can be exceeded due to the significant voltage drop across the neutral conductor. Moreover, the distribution lines/cables near the transformer can be overloaded if the charging process of the electric vehicles is not coordinated and is left freely to end users.