An isolated bidirectional half-bridge active-clamp current-fed push-pull DC/DC converter for DC microgrid applications

This paper describes an isolated bidirectional half-bridge active-clamp current-fed push-pull DC/DC converter developed for a DC microgrid. A novel modulation scheme is introduced for step-down operation, which decreases the switching losses mainly on the higher voltage side of the converter. Also, the effect on step-up operation mode is analyzed in detail. A prototype of the converter is built with a nominal output power of 600 W exhibiting a peak efficiency of 96.8% in step-down operation. Measurements show a good agreement with the simulated key waveforms. The topology has also a highly efficient step-up operation mode with a peak efficiency of 96.2%.