Analysis and validation of an LC input filter quadratic buck converter

This paper addresses the analysis and experimental validation in steady state of a non-isolated quadratic buck converter to which an LC input filter has been added. This modification ensures that the power source is continually connected and delivering power during each switching period, which yields a reduction of switching components at the input. This may even entail a time-continuous input current. Continuous input current is a desired requirement for sensitive electric power sources and electric storage systems. The space-state model of the converter and the dynamical analysis of the open-loop linearized model are presented. Steady-state analysis is also presented that allows obtaining expressions for switching ripples and average values and conditions for boundary conduction mode operation. Experimental results, performed in a laboratory prototype of the converter, are included to verify the presented analysis.