FPGA based hybrid resonant switching DC/DC converter for electric vehicles

Abstract

A hybrid switching DC-DC converter for Hybrid Electric Vehicle with reduced on state conduction losses, voltage stress and switching losses of the power semiconductor devices is presented in this paper. Zero current switching and zero voltage switching is achieved for the leading and lagging legs of the inverter by using bipolar switching method. This reduces the circulatory losses in the transformer primary. Additionally it aids in exploiting the leakage inductance of the transformer to resonate with the output capacitor. Consequently this reduces the components count and the converter size. This results in efficient energy transfer as the inductive energy and capacitive energy acquired by the output inductor and resonant capacitor are simultaneously transferred to the load during the freewheeling interval. This boosts the converter efficiency when compared to the conventional converter. During active intervals, inductor is charged and the increased capacitor voltage is offered to the load. The bipolar circuit voltage is clamped during the freewheeling interval and reduces the peak voltage overshoots that crop up during the diode reverse bias period. Simulation for the DC-DC converter is rendered with PSpice software and the experimental results shows the desired output is achieved with reduced losses under variable load conditions.