Multi-terminal electric vehicle fast-charging station based on current-fed multi-active bridge converter

Abstract

The number of fully electric vehicles (EVs) on the road is continuously increasing year by year, creating a growing demand for multi terminal EV charging infrastructure, where multiple charging terminals serving different EVs are located in close proximity. Many existing multi-terminal fast EV charging stations are based on architectures with multiple independent or modular power conversion units, in which each charging outlet requires dedicated power conversion hardware. Consequently, as the number of charging outlets increases, the amount of required hardware (semiconductors, passive components, processors, etc.) scales approximately linearly, leading to a corresponding increase in the overall cost of the charging station. As a potential solution to reduce the installation cost of multi-terminal EV charging stations, this article presents a multiport current-fed multi-active bridge (CF-MAB) converter that requires fewer components while maintaining independent port operation and enabling the integration of a battery energy storage system. In the proposed application, the CF-MAB is connected to a low-voltage DC traction grid, allowing the shared use of existing traction substation equipment, such as the low-frequency transformer and AC/DC rectifier, for both electric traction and EV charging. This approach further reduces infrastructure costs by eliminating the need for a dedicated transformer and AC/DC rectifier at the charging station. A reduced scale five-port CF-MAB prototype was experimentally evaluated under various operating conditions with a power rating of up to 10 kW, achieving a peak efficiency of up to 98%.