Analysis of high penetration of electric vehicles and photovoltaics on a greek low-voltage network

Abstract

This paper examines the scenario of high penetration of Photovoltaics (PV) and Electric Vehicles (EV) in Low-Voltage (LV) Distribution Networks (DN), using as a case study a typical DN found in Greece. The European Union (EU) has set targets and Directives that make it very likely to find in the near future DNs with a large number of PVs inducing overvoltages and uncontrolled EV charging resulting in under-voltages. Since PV production and EV charging generally happen at different times, especially in residential case studies, a DN may experience both unwanted circumstances at the same day. One way to deal with these issues is to smartly utilize distributed or centralized storage, which may additionally delay necessary investments on the DNs. This paper utilizes a case study of a typical DN found in Greece, suitably adapted to illustrate the above concepts. First, an analysis of the stress imposed to the DN by both PVs and EVs is evaluated, using as input real measurements at the beginning of the LV feeder. Then, the paper suggests a simple utilization of storage in order to keep the voltages at all nodes of the DN inside the desired limits. Finally, a short analysis regarding the power losses is presented.