Advanced Power Management in a Grid-Connected Solar-Wind Integrated DC Microgrid for Fast Electric Vehicle Charging and AC Load Applications

This paper presents a grid-connected DC microgrid system integrating solar photovoltaic (PV) and wind energy sources for high-power electric vehicle (EV) charging and AC load support. The system employs a Neutral Point Clamped (NPC) converter to reduce voltage stress on power electronic components, improve power conversion efficiency, and enhance system stability and power quality. To manage the growing energy demand from the rapid adoption of EVs, the proposed architecture includes a bidirectional DC-DC buck-boost converter for efficient EV battery charging and discharging. This converter enables flexible power flow control, allowing both fast charging (80–240 kW within ~30 minutes) and discharging modes, such as vehicle-to-grid (V2G) operation. The system utilizes renewable energy from solar and wind sources to supply the high charging power while mitigating voltage instability and reducing stress on the conventional grid. Additionally, during low charging activity or peak demand periods, surplus renewable energy can be exported to the grid, thereby enhancing grid resilience. The system's performance is evaluated through MATLAB/Simulink simulations, incorporating a coulomb counting-based State of Charge (SOC) estimation method to monitor battery performance. Simulation results confirm improved power quality, reduced grid dependency, and stable operation of the proposed DC microgrid under dynamic load and generation conditions.