Multiphase Interleaved DC-DC Converter for Fast Charging Application of Electric Vehicles

With the increase in popularity of electric vehicles (EVs) the demand of DC fast charging station is increasing. The converters required in the fast-charging station need to operate at different power level as per the SOC level of the EV battery. Hence, the efficiency of the conventional converter varies with respect to the SOC level. Hence, this paper presents a multiphase bidirectional interleaved DC-DC converter. The different phases of the converter operates either separately or together (two phases (<20%), three phases (20%80%)) as per the SOC level to ensure maximum efficiency. The analysis is shown for power output of different phases for different SOC level of operation. The bidirectional operation of the converter is also presented to enable grid to vehicle (G2V) and vehicle to grid (V2G) operation. The converter works in buck mode during G2V and works in boost mode of operation during V2G operation. The simulation of DC-DC bidirectional interleaved converter is analyzed on MATLAB/SIMULINK at power level of 12kW. This ensures high efficiency operation for (0–100) % SOC level of the battery. A 250W hardware prototype is implemented in the laboratory to validate highly efficient bidirectional operation of the converter for fast charging application.