Connection of very large public charging station to the HV transmission grid

Fast charging station will play a key role in the widespread diffusion of electric vehicles in large cities. Large public parking areas, such as park-and-ride or commercial centres equipped with fast recharge infrastructure will require dedicated grid connections to the HV transmission grid, due to the significant installed power. The interaction between those multi-MW scale recharge aggregates and the existing transmission prompt the need for electrical studies, in order to reduce the stresses on the existing network and to gain advantages from the regulation opportunities of the vehicle chargers. A test case on the Rome area is presented, showing the possible connection schemes for a very large aggregated charging stations on the HV transmission network. Harmonic interactions are evaluated by means of ATP-EMTP simulations, showing possible resonances because of HV underground cable. Utilization of charging stations as STATCOM is also examined by means of WinCreso software, showing that direct connection of large charging station to the HV level can provide valuable voltage support to the transmission network.