A novel square-wave converter with bidirectional power flow

A novel ZVS phase-shift controlled bidirectional DC-DC convertor is proposed. It possesses the conventional features of phase-shifted convertors, including constant switching frequency, zero-voltage switching (ZVS) and voltage control by phase-shift. However, the new convertor has been improved by developing a bi-directional power flow capability and applying synchronous rectification, hence the on-state voltage drop of the active devices are small. Therefore it is recommended for use in an electric vehicle (EV). In this paper, the principle of circuit operation of the proposed convertor was described in detail with mathematical calculations, and the experimental results were also given to verify the concept.