Influence of Battery Parameters in MMC-based Fast Charging Stations with 400 V/800 V Charging Ports

The transition to electric vehicles represents a pivotal step towards sustainable transportation, although concerns related to long charging times, limited driving range, and battery disposal pose significant challenges. To overcome these obstacles and expedite the adoption of electric mobility, there is a growing demand for ultra-fast charging stations. Modular multilevel converters have emerged as a promising solution for this application, offering advantages such as voltages and currents with low harmonic content, and the possibility to integrate distributed battery energy storage systems. Additionally, thanks to the flexibility of this converter, storage systems based on different technologies or characterized by different parameters, such as second-life batteries, can be adopted. In this regard, this paper provides the design criteria to select the capacity of the installed storage systems considering the influence of battery parameters, analyzing an ultra-fast charging station with 400 V and 800 V charging spots as case study. The effectiveness of the proposed methodology was verified by means of numerical simulations hereby presented.