EV charging station integrating renewable energy and second-life battery

This paper investigates the integration of wind power, Photovoltaic (PV) solar power, and Li-Ion battery energy storage into a DC microgrid-based charging station for Electric Vehicles (EVs). The goal is for the Renewable Energy (RE) sources to provide as much of the charging energy as possible. The facility will be grid connected so that charging can occur during cloudy, windless days. The grid connection also permits exporting power when generation exceeds demand within the microgrid. It is proposed that second-life lithium-ion batteries be integrated into the proposed system to serve as an energy buffer and provide emergency energy upon loss of the grid connection. The Simulink modeling and simulation components of the charging station includes the solar PV, wind, EV batteries, and second-life batteries with their associated controls. The battery model is based on laboratory tests conducted during the project. Control functions and algorithms enabling the system to operate in various modes are developed, and simulation results are presented.