A novel hybrid ZVZCS full-bridge converter suitable for wide input voltage range

A novel hybrid converter with two full-bridge at primary side and hybrid combination of rectifier diodes at secondary side is proposed. The rectifier output voltage is synthesized of two controlled transformer output voltages all the time, which is significantly improved to achieve reduced output filter size and rectifier diodes voltage stresses. Besides, the circulating current decays to zero in both full-bridge resulting in minimized conduction loss and duty-cycle loss. Therefore, the proposed converter is suitable for wide input voltage range application. Moreover, two transformers equally share the total VA rating due to the symmetrical operation with the proposed modulation strategy. Furthermore, an auxiliary inductor is employed to achieve zero-voltage and zero-current switching for all switches over the whole load range with less increased current stress. In the paper, the operation principle and steady-state analysis of the proposed converter are illustrated. Also, experimental results with 200-480V input voltage are demonstrated to verify the advantages.