The aim of reducing charging duration and the expected growth of the number of electric cars leads to a variable and high power demand on the current and near future fast charging stations (FCS). Currently, the voltage adaption from the MV level to the FCS is provided by a bulky 50/60 Hz transformer, leading to limited possibilities in the scalability in terms of charging power of the FCS. Therefore, in this paper three different modular possibilities to realize these systems by directly connecting a power electronic based solution to the medium voltage (MV) grid are investigated. The necessary isolation is realized in the DC-DC stage by the medium frequency transformer of the quadruple active bridge, which, as it will be shown, can be connected in different configurations. The prospective best solution, the cascaded H-bridge + interphase quadruple active bridge, is analyzed in more detail. The benefit of this architecture is the direct MV connection possibility and simultaneously natural power balancing among the three phases. Furthermore, the architecture provides modularity and scalability with respect to the desired power level of the charging station.