Recovery-less boost converter for Electric Vehicle

The miniaturization and higher efficiency performances of boost converter for electric vehicle have been required. In this paper, a novel trans-linked recovery-less boost converter, which can reduce the size of the main inductor for the boost operation and can solve diode recovery problem without the additional active power switch is proposed. The size reduction of the main inductor is realized by interleaving and trans-linked techniques. And suppressing diode recovery phenomenon is realized by the additional inductor because the current transition through the diodes is softly. Furthermore, zero current switching (ZCS) can be achieved as well in active switches at turn-on. Therefore the switching loss in active switching devices is also reduced. The additional inductor is required optimum design to suppress diode recovery phenomenon effectively. This paper describes the design theory of additional inductor and transformer turn ratio. The fundamental operation of the proposed boost converter is described and confirmed on the basis of the experimental results. In the experimental results, suppressing diode recovery and realizing ZCS operation is confirmed actually. As a result, the proposed circuit achieves 0.4% higher efficiency as compared with one of conventional circuit. As future trends, reverse buck topology is presented for practical aspect.