Optimized design of ZVS-ZCS PWM FB DC/DC converter with lossless snubber

Using the snubber net made of diodes and capacitances, in the zero-voltage-switch full-bridge (ZVS-FB) converter, can not only decrease the parasitic resonance in the rectified voltage of the transformer secondary, but also obtain zero-current-switch (ZCS) in the lag leg. In addition, this topology can eliminate the circulating current existing in the ZVS-FB topology circuit. The diode clamp circuit introduced in the transformer primary can apparently restrain the peak voltage resonance in the rectified diodes. By applying those techniques, one 3 kW DC/DC converter has been achieved and its transformer primary current waveform and rectified voltage waveform of the transformer secondary has been illustrated in this paper.