Family of universal bidirectional DC–DC converters with an extended voltage gain

Abstract

This study presents a family of non-isolated bidirectional DC–DC converters with extended DC gain. Increasing of the DC gain range is achieved due to splitting the base inductor and also by using magnetically coupled inductors. All the variants of the proposed schemes are based on the use of the dual-half-bridge DC–DC converter. As a result, a number of improved schemes of buck, boost and buck–boost bidirectional converters were obtained with the possibility of increasing the voltage-boosting ratio in boost converter mode and simultaneously reducing the voltage gain in the buck converter mode. The converters have a symmetrical structure, and this ensures the operation of each of them in four modes, which gives greater flexibility in matching the voltages of the power supply with storage devices. The formulas for the DC gain, maximum voltage stresses on the switches and a comparative evaluation of these parameters are presented. The modes of operation and equivalent schemes are considered in detail. For each of the schemes, the corresponding tables for the operation of the transistors are given. The analyses of the dynamic modes of the proposed converters is shown. The experimental verification completely confirms the theoretical results.