Nowadays, Electric Vehicle (EV) chargers need to guarantee fast charging and, in the scope of smart grids, they should also be able to provide ancillary services to the grid, thus allowing bidirectional power flow. As an answer to these requirements, in this work it is proposed a compact modular fast charging system allowing Grid to Vehicle (G2V) and Vehicle to Grid (V2G) operation. To guarantee modularity and lower operation voltages the system uses an association of single phase inverters. Also, high frequency transformers are chosen to allow volume reduction of the whole EV charger. The obtained results show that the proposed system allows fast charging (less than 30 min), G2V and V2G operation, and minimum power quality impact in the connection to the grid, guaranteeing that the grid currents Total Harmonic Distortion is lower than 5%.