Naturally Clamped Zero-Current Commutated Soft-Switching Current-Fed Push–Pull DC/DC Converter: Analysis, Design, and Experimental Results

The proposed converter has the following features: 1) zero-current commutation (ZCC) and natural voltage clamping (NVC) eliminate the need for active-clamp circuits or passive snubbers required to absorb surge voltage in conventional current-fed topologies. 2) Switching losses are reduced significantly owing to zero-current switching of primary-side devices and zero-voltage switching of secondary-side devices. Turn-on switching transition loss of primary devices is also negligible. 3) Soft switching and NVC are inherent and load independent. 4) The voltage across primary-side device is independent of duty cycle with varying input voltage and output power and clamped at rather low reflected output voltage enabling the use of low-voltage semiconductor devices. These merits make the converter good candidate for interfacing low-voltage dc bus with high-voltage dc bus for higher current applications. Steady state, analysis, design, simulation, and experimental results are presented.