Hybrid DC-DC buck converter with active switched capacitor cell and low voltage gain

This paper proposes a novel dc-dc buck converter that is composed by an active switched capacitor cell and a conventional buck converter. The proposed converter is named as hybrid buck converter and it presents static gain from 0 to 0.5, maintaining the typical linear characteristics of the buck converter and it reduces the voltage stress on the power components. A theoretical steady state analysis to obtain the steady values of all capacitor voltages and the inductor current are presented. A generalization of the switched capacitor cell is also proposed to show the extensive applicability of this structure to dc-dc high step-down voltage ranges. Simulation and experimental results are reported herein to corroborate the proposed structure and the theoretical analysis. An efficiency result is also reported in this paper for the rated power. The prototype specification designed was: 1 kW, 600 V in input voltage and 150 V in output voltage.