A ZVS-PWM Bi-directional DC-DC Converter for Electric Vehicle Systems

This paper designs a low-cost DC-DC converter topology with hybrid energy storage for the application of electric vehicle system. In the proposed topology the bidirectional power flow among the battery, super-capacitor and the DC motor are maintained by a single power switch, along with an auxiliary switch, coupled inductor and resonant inductor. To reduce the switching stress the ZVS (Zero Voltage Switching) condition is achieved by utilizing the auxiliary diode, resonant inductor and capacitor. Further the size of the converter is reduced by using an auxiliary thyristor which is responsible for the power flow during motoring condition. Moreover, in order to avoid the frequent charging and discharging of battery, the voltage profile of the super-capacitor is maintained higher than the battery by the converter. The working of the proposed topology is tested and verified through MATLAB simulation.