Abstract
This paper presents the power electronics architecture of an electric vehicle (EV) charging station operating as a DC microgrid with an AC grid interface. The grid-interface converter is implemented using an interleaved bidirectional DC–AC converter supporting bidirectional power exchange with the utility grid, as required for vehicle-to-grid (V2G) operation, while providing ancillary services to the utility grid. In addition to bidirectional power flow, the converter supports active power curtailment, reactive power compensation, and active power filtering, improving grid support and power quality. Within the DC microgrid, bidirectional converters manage the energy exchange between the DC bus, stationary battery storage, and electric vehicles. The EV charging stage is implemented using a set of parallel bidirectional dual active bridge (DAB) DC–DC converters, enabling galvanic isolation, high power density, and efficient bidirectional energy transfer between the DC bus and the vehicle batteries. To enhance the sustainability of the proposed system, a photovoltaic generation unit is connected to the DC bus through a dedicated interleaved power electronics converter. The control strategies and validation of the proposed architecture are presented with emphasis on converter operation and grid-support functionalities. The results demonstrate stable operation during battery charging and discharging, bidirectional power transfer between the EV battery and the DC bus through the DAB converter, bidirectional power exchange between the DC bus and the utility grid through the grid-interface converters, and a significant reduction in the total harmonic distortion (THD) of the grid currents while enabling advanced ancillary grid services.