Design and implementation of a ZCS two-switch forward converter with variable inductor

A zero-current-switching (ZCS) two-switch DC-DC forward converter with variable-inductor is presented in this paper. The quasi-resonant technique is employed to achieve ZCS operation. This variable inductor technique is used to reduce the switching losses and the peak value of the output-diode current. Thus, the conversion efficiency can be improved. Moreover, the voltage across the active switch is clamped at the DC-source input voltage. So, the voltage stress of the active switch is less than that of the conventional DC-DC forward converter. Finally, a prototype circuit is implemented to verify the performance.