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In this paper, a systematic and analytical study of non-isolated topologies belonging to the family of reduced redundant power processing (R2P2) converters is presented. Based on this study, all the non-isolated R2P2 topologies that can be implemented in reality are derived. Detailed examples clarify all possible cases of this analysis. In addition to this, the voltage ratio and the efficiency for each one of the R2P2 configurations are calculated, being further illustrated with examples. A comparison among configurations is also discussed with criteria the high step-up voltage gain and efficiency, aiming for high-power applications. One of these R2P2 converters is selected for further examination, as the most suitable for such applications. The theoretical analysis, as well as the calculations of the step-up voltage ratio and efficiency of the selected converter, is compared to experimental results conducted on a 2-kW laboratory prototype designed to operate in various step-up voltage ratios and in a high-power range, proving the effectiveness of the proposed investigation. [ABSTRACT FROM AUTHOR]

In this paper, a nonisolated high step-up dc/dc converter, belonging to the family of reduced redundant power processing converters (R2P2), is investigated for high-power applications. The selection of this topology as the most suitable for such applications among those belonging to the R2P2 family is justified. Emphasis is given on the theoretical analysis of the real step-up voltage ratio of the converter, and voltage and current stresses under continuous and discontinuous conduction modes of operation, taking into account the nonideality of the topology components, namely the parasitic resistances of semiconductor devices and inductors and the voltage drop of diodes. The theoretical analysis and the behavior of the selected converter are experimentally validated through a 2 kW prototype. Moreover, the overall efficiency of the chosen converter is experimentally investigated for various step-up voltage ratios and for a high-power range, considering a waste heat recovery system for a maritime application. [ABSTRACT FROM AUTHOR]

Active clamp topologies of low power dissipation have become a very attractive solution in order to limit overvoltages in flyback converters. Although many suitable topologies have been introduced for the case of discontinuous conduction mode (DCM), where the duty cycle value depends on the load level, in continuous conduction mode (CCM) it is more difficult to appropriately design such topologies so as to "sense" load changes-due to the small duty cycle divergence under wide load variation. Taking for granted that in order to achieve high power-factor correction in these converters, CCM is a more attractive mode of operation, a drastic solution for this case that will manage to eliminate voltage stresses under wide load changes has become very essential. For this purpose, this paper presents an active clamp topology with small power dissipation, suitable for flyback converters operating in CCM mode. Its main idea is the Use of a load. dependent current source, consisting of an auxiliary converter operating in DCM mode. Experimental results highlight the effectiveness of the proposed topology under wide load changes, establishing it as an appropriate solution in order to develop flyback converters, even at the power range of 500 W. [ABSTRACT FROM AUTHOR]