High Efficiency Three Phase Interleaved Buck Converter for Fast Charging of EV

The electric vehicles (EVs) is the future of transportation to match the demand of the increasing population by reducing dependency on fossil fuels. The EVs are inefficient today due to the requirement of the long charging hour. Therefore, a fast charger is essential for EVs to fulfill the high mileage demand and to reduce time of charging of electric vehicles leading to better performance as compared to EVs today. In a fast-charging station, high power is required to charge the vehicles in a short time, which varies with the charge level of the battery. The proposed work is on a three- phase Interleaved buck converter for fast charging operation. However, the fast charging operation cannot be applied for complete (0-100)% SOC level of the battery, this may reduce the battery life. The algorithm is proposed to operate the phases of interleaved buck converters based on the SOC level of the battery. In the proposed method the operation of the converter below 20% and above 80% SOC level is not at a fast- charging level. The proposed interleaved converter phases (one for low, two for medium, and three for high) are selected for operating the converter at various power levels also maintains high efficiency. Additionally, the converter is operating in constant voltage mode in the fast charging region (20%- 80% SOC). The Coulomb Counting Method is implemented to estimate the SOC level. The preliminary analysis and simulation results are included in this paper.