Recovery-less boost converter with saturable inductor for electric vehicle applications

One of the main problems of Electric Vehicles is the mass and volume of the electric powertrain. In particular, the power converters, that interface the storage unit with the motors, are composed of bulky and heavy components. These converters suffer from considerable power losses caused by hard-switching and recovery phenomena. Therefore, the efficiency of the converter decreases, and the mass and volume increases because it is necessary to use bulky and heavy cooling systems to dissipate the power losses produced by these phenomena. This study proposes a novel recovery-less boost converter that can achieve zero-current switching and reverse-recovery reduction by using two saturable inductors for the reduction and softening of the switching transition. Consequently, a high-efficiency performance can be achieved. In addition, the proposed two saturable inductors offer advantages of mass and volume reduction of the auxiliary inductors in comparison with other conventional converters for reverse-recovery reduction. Therefore, power density of the proposed converter can be increased. In this paper, the circuit configuration, the operating principle, and the reverse-recovery reduction of the proposed converter are described. Moreover, the design procedure of the proposed saturable inductors is presented. Finally, the effectiveness of the proposed converter is validated through experiments. As a result, a reduction in both the recovery phenomenon and the auxiliary inductor volume is confirmed, with a 72% reduction in the recovery phenomenon and a 63% reduction in the auxiliary inductor volume.