Simple low-cost ZVS bidirectional forward converter with phase shift control and voltage matching for low power applications

In this study, a new zero-voltage switching (ZVS) output inductor-less bidirectional forward (OILBF) converter is presented. The OILBF has two diodes less than the conventional forward converter and is convenient for low-power bidirectional applications. Moreover, the OILBF converter uses the leakage inductance of transformer as the forward inductor. In the proposed OILBF, two capacitors paralleled with main switches realise ZVS conditions for main switches in both directions without any auxiliary switches. Also, the reset of the converter transformer is done without any additional circuit. The proposed converter structure due to employing simultaneously OILBF topology with the simple auxiliary soft-switching circuit is simple and low cost. The ZVS soft-switching range is from light load to full load which enhances the converter efficiency. Phase shift is applied with the proposed converter. The proposed converter is completely analysed and its design approach is considered. Finally, an experimental prototype is implemented to verify theoretical results.