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 is also discussed among configurations with criteria the high step-up voltage gain and efficiency dedicated for high power applications and one of them is selected for further examination. The theoretical analysis, as well as the calculations of the step-up voltage ratio and efficiency of the selected converter are compared to experimental results conducted on a 2kW laboratory prototype designed to operate in various step-up voltage ratios and in a high-power range, proving the effectiveness of the proposed investigation.

Considerations are held about the specificationin whichthe PV plants have to fulfill so that they can be installed on marine vessels. Initially, a brief description of the typical electrical grid of ships is presented, distinguishing the main parts, reporting the typical electrical magnitudes, and choosing the most preferable installation areas. The technical specifications,in whichthe PV plants have to be compatible with, are fully described. They are determined by the special marine environmental conditions, taking into consideration parameters like wind, humidity, shading, corrosion, and limited installation area. The work is carried out with the presentation of the most popular trends in the field of solar cell types and PV system technologies and their ability to keep up with the aforementioned specifications.

This article proposes a galvanically isolated high step-up dc–dc converter for dc microgrid applications. By the use of an inductor, a transformer, a voltage multiplier, and an active clamp, the proposed converter is able to provide very high dc voltage gains along with reduced voltage stress across the semiconductors, zero-voltage and zero-current switching for the switches and the diodes, respectively, low ripple input current, and reduced component count. The analysis of the converter in continuous conduction mode (CCM) and a comparison with other previously published isolated topologies are also presented. Finally, a prototype has been built for a power of 250 W to verify the functionality of the proposed converter in CCM operation, with an input voltage range of 20–28 V and an output voltage of 400 V.

In this paper a non-isolated 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 non-ideality 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 2kW 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.

The prevalence of electromobility requires reliable battery energy storage systems that can assure the high demands for extended driving range of the electric vehicles. To meet this demand, the Battery Management System (BMS) plays a major role. The requirements for the BMS variate according to the specific needs for each application. In this paper, a high-equalisation current BMS with high efficiency is implemented, based on the bi-directional flyback converter. The modelling of the converter considering non-ideal elements is combined with the Genetic Algorithm to select the parameters of the converter that maximise the efficiency of the BMS. As a result, a BMS for high-capacity lithium cells is implemented, achieving a 91.73 % efficiency for a balancing current of 5 A, and a peak efficiency of 94.19 % for a balancing current of 2 A. The proposed BMS follows the bi-directional module-to-cell configuration and is intended for integration on independent cells. As a result, a smart cell is developed that can be used in second-life battery applications.

In this paper, a detailed design methodology of a Resonant Dual Active Bridge (R-DAB) converter is proposed, for battery charging applications. The converter design methodology is tailored to the charging profile of a Li-ion battery and is based on unique operating points (UOPs) that derive from a dual control method analysis. Specifically, both Pulse Frequency Modulation (PFM) and Phase-Shift Modulation (PSM) are adopted, to minimize the switching losses and the reactive power at the resonant tank. A detailed flowchart is presented, considering multiple design parameters and the UOPs, so that the resonant tank parameters are not overestimated. Finally, a 1kW|30A laboratory prototype charger is designed and evaluated, using a closed loop control system. The evaluation of the experimental results proves the significance of the dual control method and verify the proposed design methodology.