New Multi-Leg Converter for DC Microgrid with Two Duty Cycles

Abstract

In recent times, important contributions and the incorporation of renewable sources, such as photovoltaic, fuel cells, etc., are the main reasons for the popularity of DC microgrids. Integrating renewable sources into the microgrid requires high-voltage, high-efficiency DC-to-DC converters. Without modification, traditional converters are not suitable for achieving the required voltage in microgrid applications, due to the requirement for a large duty cycle, inductor resistance, voltage rating of switches, reverse recovery of the diode, high current rating inductors, etc. Various converters based on the circuitry of voltage multipliers, switched inductors/capacitors, coupled inductors, transformers, etc., have been proposed in the literature and have their drawbacks. In this paper, to realize significant voltage gain with two duty cycle controls, a new multi-leg (ML) converter is recommended as a solution for use in DC microgrids. The converter is designed by incorporating multiple legs into the boost converter. The implications of the proposed converter are reduced device voltage stress, small inductors and capacitors, two-duty cycle control, triple mode operation, single-stage conversion, etc. The proposed converter’s power circuits, mode of operation, and design equations of the converter are presented. The non-ideal model of the proposed converter is discussed, and efficiency is analyzed. The effect of unequal insurance on the operation of the converter is discussed. Comparative studies of converters are provided to draw attention to the benefits of the converter. The results of the experiments are shown to prove that the analysis and performance of the converter are correct. The discontinuous mode of operation and unequal inductance case of the converter are studied with the help of a simulation model.