Design of circuit for battery charging of electric vehicles: From renewable energy sources

Electric vehicles and plug-in hybrid electric vehicles are two concepts that are gaining popularity in order to reduce our dependence on fossil fuels. In this paper, a full bridge, current fed, interleaved, isolated DC-DC converter is proposed for battery charging of electric vehicles from solar PV or fuel cells. It boosts voltage of around 36 V to 270 V. Interleaving leads to lesser input current ripple, a factor crucial for sources like solar PVs and fuel cells and lesser stress on switches. The concept of soft switching is used to reduce switching losses. Simulation results are presented for a power level of 3.45 kW. A scaled down, 200 W hardware model of the circuit was built and tested. A closed loop feedback system was also designed using k factor method to provide constant output voltage.