Control of Bidirectional Power Transfer in Grid-tied Fast Electric Vehicle Charging System

An increasing adoption of electric vehicles (EVs) is placing additional demands on the power grid. A potential solution to alleviate this strain is the use of bidirectional chargers, which can not only charge EV batteries but also assist the power grid. Bidirectional converters, including an AC-DC converter and a DC-DC converter, facilitate both the charging and discharging of the battery. By altering the operational mode of the DC-DC converter, its behavior can change accordingly. Plug-in Hybrid Electric Vehicles (PHEVs) can function in "vehicle-to-grid" (V2G) mode, allowing EV batteries to exchange power with the grid in both directions. The aim of this research is to develop a control strategy that optimizes power flow for both V2G and grid-to-vehicle (G2V) operations in EVs. This can help in reducing peak loads, balancing the grid, maintaining voltage stability, and improving the overall reliability of the electrical system. Through V2G technology, distributed energy stored in EV batteries can be fed back into the grid, acting as a form of reserve power and supporting grid stability. A bidirectional discharging circuit also enables power to flow from the grid to the vehicle battery. This study focuses on key parameters such as battery characteristics, inverter current, and grid current within the G2V and V2G framework. MATLAB/Simulink is utilized to design and simulate the bidirectional charger for EVs, with a focus on both V2G and G2V modes of operation.