Optimal coordination of a pool of different EV charging stations

The transport sector will contribute to the decarbonisation goals by massively replacing internal combustion engine vehicles with electric vehicles (EVs). In Europe, up to 70 million EVs are expected by 2030. The diffusion of EVs will be accompanied by 50-70 million charging points connected to the distribution systems (at medium and low voltage levels). The EV charging causes power quality and operation issues, such as line overloading, voltage violations, and voltage unbalances. It will require extensive investments to develop a distribution system suited to face the electrification of heating and transportation. Using suitable control systems for optimal charging that consider charging session features and network criticalities can mitigate the impact of EVs on distribution grids and contribute to postponing or even avoiding significant investments. The paper proposes a strategy to reduce the effects of public charging on low-voltage networks. If already burdened by the increased electrification of end-use consumption and domestic vehicle charging, these networks are susceptible to significant voltage drops or overcurrents. The proposed strategy involves developing a signalling system that informs vehicle owners whether a charging station can guarantee a full charge based on current grid conditions. An Italian LV unbalanced network and charging habits in parking lots derived from the latest literature are used to demonstrate the effectiveness of the proposed approach.