Analysis and Experimental Verification of High-Efficiency DC-DC Converter for DC Microgrids

This paper introduces a DC-DC converter with high efficiency for renewable energy DC microgrids. The proposed converter is designed to elevate the voltage produced by photovoltaic (PV) modules from 30V to 400V, allowing seamless integration of PV into a DC microgrid. The converter incorporates a voltage lift circuit to enhance the conversion gain of voltage and a snubber circuit to minimise voltage stress on semiconductors, resulting in high efficiency as well as enhanced voltage conversion gain. The design also effectively clamps and recycles the energy of the leakage inductor to further enhance conversion efficiency. By significantly reducing the MOSFET voltage stress, the proposed design leverages low-rated MOSFETs, thereby reducing losses and improving efficiency. The proposed converter uses as few components as possible, reducing manufacturing costs. Operations and evaluations were carried out in a steady-state mode, followed by constructing a lab prototype to validate the practical performance. The findings aligned with the theoretical predictions, showing a top conversion efficiency of 95.1%.