Analyzing Power Losses and Performance of an Isolated DC-DC Converter for Renewable Energies Systems

Abstract

DC-DC converters are essential in the interconnection of photovoltaic (PV) systems and systems that operate at different voltages, frequencies, and powers, such as smart grids. Due to the energy transition, and therefore the need for high efficiency in PV systems and smart grids, there is a great challenge to develop DC-DC converters with the highest possible efficiency. Therefore, in this paper an isolated DC-DC converter with high efficiency and easy implementation is developed, in comparison with other similar structures. In isolated converters it is necessary to address the analysis and design of the transformer. Poor performance of this element can contribute to high losses and low efficiency of the converter topology. This study proposes an isolated DC-DC converter (FBDC) that operates at different levels of harmonic content in its supply. The design is subjected to two levels (2L) and three levels (3L), which affects the THD value. The proposed converter model is simulated in MATLAB-Simulink and validated in a laboratory prototype. Finally, the prototype is incorporated into the multilevel FBDC topology, obtaining an efficiency of 96.6% for 2L and 97.0% for 3L in the laboratory, showing the high performance of the proposed design.