Design and Implementation of a New Resonant Soft-Switching dc/dc Buck Converter

This paper presents a new step-down resonant dc-dc converter derived from the family of Switched-Resonator converters (SwRC). Soft-switching conditions are provided for both switches at turn on and turn off transitions by switching under zero-current (ZCS). ZCS technique switching losses and enables the converter to operate at higher switching frequencies which enhances the converter power density. Moreover, it gives better efficiency with few element count and decrease the implementation cost. Due to the turning-off of the resonant diode under ZCS condition, the problem of reverse recovery which is a problematic issue especially in fast diodes is obviated. By employing a simple LC resonant network, soft-switching condition is provided for all the semi-conductor devices. The circuit is simulated by PSpice software and the results are presented. Experimental results from a laboratory prototype are also presented. Simulation and practical results confirm integrity of the presented theoretical analysis and show the full-load efficiency at 92.32%.