Hybrid Nonisolated DC–DC Converters Derived From a Passive Switched-Capacitor Cell

This paper presents a hybrid nonisolated dc-dc commutation cell, which is generated by the integration between conventional commutation cell and ladder-type passive switched capacitor (SC) cell. From the resulted hybrid cell are derived three different dc-dc converters: a buck-type, a boost-type, and a buck-boost-type. The three structures are analyzed in this paper and are presented the topological stages, static gain characteristics in continuous conduction mode and discontinuous conduction mode, steady-state analysis. The analyses are generalized in relation to the number of switched-capacitor cells employed, which allows the increase of the rated gain of the converters by adding more SC cells. In addition, the proposed hybrid nonisolated dc-dc commutation divides naturally the voltage stress among the semiconductors and capacitors of the power stage. A 1-kW prototype was developed to verify the operation of the three proposed converters and their theoretical analysis. For the buck-type topology, designed with an input voltage of 600 V and output voltage of 450 V, a peak efficiency of 99.2% and efficiency at rated power of 99% were obtained.