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This paper presents an efficiency-enhanced low-profile zero-voltage-transition (ZVT) synchronous non-inverting buck-boost converter for 48-V tens-of-Watt output applications. By only using three auxiliary components shared between two switching nodes, zero-voltage switching (ZVS) of all four power switches and zero-current switching of the auxiliary switch are achieved in the proposed converter to minimize the switching power loss. Compared with the existing ZVT topologies, the proposed converter reduces the required number of auxiliary components, thereby decreasing the converter volume and power loss. In addition, the proposed converter can be configured into the buck mode with full ZVS capability to support a wide input range from 36 V to 90 V. Experimental results show that the proposed converter can operate at 1 MHz and deliver a maximum output power of 75 W. The measured peak power efficiencies achieve 92.5% and 96.3% in the buck-boost mode and buck mode, respectively. Compared with the state-of-the-art ZVS-based buck-boost counterpart, the proposed converter reduces the volume of the auxiliary circuit by ~2 times even with 28% increase in the maximum load current and two times reduction in the switching frequency, and provides higher peak power efficiencies in both buck-boost and buck modes. [ABSTRACT FROM AUTHOR]

High step-up conversion is an indispensable feature for the power processing of low voltage renewable sources in grid-connected systems. Motivated by this necessity, this paper presents a study on non-isolated dc-dc converters based on the conventional Boost converter that can provide such feature with high efficiency. By the topological variation and gain cell concepts, it is demonstrated that these converters can be treated as a unique generalized converter, called Boost Converter with Gain Cell (BCGC). The operating principle, the key waveforms and the components stresses of the BGCG are analyzed for the continuous-conduction mode, independently of the employed gain cell. A methodology to create the gain cells is developed from the combination of coupled inductors and voltage multiplier techniques. In order to verify the realized analysis, a 150 W prototype concerning to the proposed generalized converter and able to operate with several different gain cells is developed for the comparison between theoretical and experimental static gain results. [ABSTRACT FROM PUBLISHER]