Novel Forward-Flyback Hybrid Bidirectional DC-DC Converter

This paper presents a novel topology named forward-flyback bidirectional dc-dc converter (BDC), which is a hybrid of forward and flyback converters. The windings of forward and flyback transformers are connected in series on the primary side and in parallel on the secondary side. The proposed converter has no startup problem and no high voltage spikes on the switches, which otherwise are inherent for current- and voltage-fed-type bidirectional converters. It is easy to achieve soft switching by proper control and design. The built-in flyback transformer acts as a filter inductor, so the current ripple is smaller than flyback BDCs. In this paper, the operation principles and characteristics of the proposed topology are analyzed in detail. The advantages aforementioned are verified with experimental results of a 300-W prototype.