Impact Study of Electric Vehicle (EV) Integration on Low Voltage (LV) Grids

Large scale deployment of electric vehicles (EVs) has become a very interesting option because it can both reduce the greenhouse gas (GHG) emission from the transport sector and facilitate the integration of more renewable energy resources (RES) by providing the flexibility of EV charging demands. Although the EV grid integration is promising, the impact of the EV grid integration has to be investigated in order to identify the bottlenecks of power systems for the EV grid integration and assess different charging scenarios.

This paper is focused on the impact of EV grid integration on low voltage (LV) grids. The work consists of modeling a typical LV grid, EV charging schedule managment, and impact study of different charging scenarios on LV grid. The modelling work of the LV grid is done using the data from the Bornholm power system.

The topology data of the LV grid are used to develop the single line diagram (SLD) of the LV grid. The demand profiles of end-users are determined by the end-user yearly consumption and avreaged demand profiles of different customer types in Denmark. Five charging scenarios have been tested using the developed LV grid.

The first two charging scenarios are dumb charging all day and dumb charging night. The third charging is timed charging. The fourth and fifth charging scenarios are fleet all day and fleet night charging scenarios. Beside the five charging scenarios, two charging power levels will be tested as well in combination with the charging scenarios.

The two charging power levels are 1 phase 16 A and 3 phase 16 A. The loading of the power components and voltage profile are analyzed to quantify the impact of the charging scenarios and charging power levels on LV grids.