Traction powered multiport DC-DC converter for bidirectional EV charging application – HIL simulation results

The limited availability of public electric vehicle (EV) charging infrastructure poses a significant challenge to EV adoption in urban areas. This underscores the need for cost-effective solutions that enable charging for a large number of EVs, particularly for multiterminal charging stations. One promising approach to reducing installation costs is the implementation of a current-fed multi-active bridge multiport converter, powered by existing DC traction infrastructure. The use of a multiport converter allows for sharing electric components between several ports, reducing total number of elements required, compared to conventional systems, where each EV charger relies on a separate converter. Additionally, connection to the DC traction grid enables sharing some of the substation equipment between the traction network and the EV charger, further lowering installation costs while providing additional benefits, such as DC grid voltage stabilization and transit transport braking energy recuperation. In the case studied in the paper, the use of the converter reduced catenary voltage drops by $10 \%$ and voltage surges by $30 \%$, compared to $\pm 35 \%$ in the base scenario (without a converter).