High-Power Four-Port Converters With Integrated Storage for Fast and Slow EV Charging

This article presents two isolated four-port converters for high-power electric vehicle (EV) fast-charging applications. One converter is based on fully processed power conversion (FPPC), while the other adopts partial power processing (PPPC). By utilizing both FPPC and PPPC configurations, the proposed design achieves a reduction in size and cost. In addition, the PPPC configuration allows partial power to flow directly from the energy storage system to the EV, further reducing cost by lowering the converter rating, minimizing losses, and improving efficiency. The article also addresses internal coupling challenges in multiport systems by introducing a dual decoupling approach, which combines hardware-based impedance design with software-level control using frequency and phase shift modulation. Detailed mathematical modeling for power flow analysis, along with thermal and reliability analysis, is provided to evaluate performance. The proposed converters are validated through simulation, and a laboratory prototype of 1 kW is used to confirm the effectiveness of the proposed converter design. The PPPC configuration achieves a peak efficiency of 98.1%.