Modified EV Charging/Discharging Control for Hybrid DC Fast Charging Stations

The future of Electric Vehicles (EV) depends on fast-charging stations powered by Renewable Energy Source(RES), particularly solar Photo-Voltaic (PV) systems. Integrating PV, EV, and the electric grid can cause specific issues when it comes to supplying high-quality electricity. This paper presents a model of an integrated PV-grid-EV fast charging station that consistently delivers power with better power quality. The performance of the proposed charging station is validated for bidirectional power flow in Hybrid DC Fast Charging (HDCFC) station with continuously varying solar insolation. The design of the HDCFC station controller is to charge the EV by reducing the dependence on the electric grid and utilising maximum energy from the PV by maintaining the DC link voltage constant. The dynamic response of the proposed charger is investigated under varying solar insolation and load conditions and the tracking capability is found accurate and sensitive to varying conditions. The smooth transition shows better performance of the hybrid charger utilising the maximum benefit of PV during high solar insolation. This study covers the dynamic performance of the overall system, THDi and power flow control for different modes of operation.