Reverse-recovery current reduction in a ZCS boost converter with saturable inductors using nanocrystalline core materials

Abstract

Electric Vehicles demand high efficiency power converter in their powertrains in order to use the energy of the storage unit in a better way. Specifically, the power converters, that interface the storage unit with the motors, are usually composed of high-losses components. Moreover, the topologies used in these systems present conditions of hard switching and reverse recovery phenomena that reduce the total efficiency in the vehicle. This work analyzes the recovery-less boost converter that can achieve Zero-Current Switching, reverse-recovery reduction and softening of the switching transition. Due to the technique of using two saturable inductors. In addition, the use of next-generation magnetic materials for increasing the efficiency and reducing the reverse recovery current is studied. In this paper, the circuit configuration, the operating principle and the reverse-recovery reduction of the recovery-less converter is reviewed. Moreover, the comparison of ferrites and nanocrystalline soft magnetic materials is presented. Finally, the effectiveness of the proposed comparison is validated by experimental tests. As a result, reduction of the peak recovery current and increase of the efficiency are confirmed, achieving a 71% of reduction of the recovery current and 0.25% of efficiency increase at 1kW of output power.