Design of a new MV network to supply electric vehicle charging stations. A real case study in Terni

Electric mobility spread is one of the main challenges for the distribution network: the connection of high and unpredictable loads to the grid and the need for ever faster recharges can lead to power quality issues. This paper proposes the implementation of a network specifically dedicated to supplying electric vehicles, to cancel electric mobility impact on the existing distribution grid, at the same time managing the power system in a more flexible and resilient way. A portion of the distribution grid of Terni, consisting of 2 primary substations and 18 secondary substations, has been used as a case study, using real data provided by ASM Terni, the distribution network operator. The ability of the system to supply electric vehicles was analyzed, evaluating the maximum number of vehicles that the system can host. Most suitable configurations were identified using power flow and fault analysis performed with OpenDSS software. Finally, the system behaviour in case of disconnection of a primary substation was evaluated, showing that the proposed solution significantly improves grid resilience.