A Novel Equivalent Circuit of DAB Converter to Investigate Current Stress and ZVS Range

Abstract

The Dual Active Bridge converter (DABC) is an isolated bidirectional DC–DC converter that has emerged as a significant research focus in both academia and industry due to its advantages, including galvanic isolation, high power density, and inherent zero-voltage switching (ZVS) capability. It is commonly used in applications such as solid-state transformers, microgrids, and energy storage systems.However, the presence of a high-frequency transformer introduces reactive power, which increases further under voltage mismatch conditions. This elevated reactive power results in higher circulating current, higher losses, and lower the efficiency. M oreover, t he v oltage r atio significantly influences t he Z VS c onditions, p articularly u nder light-load operation. Therefore, the voltage ratio plays a important role in improving the maintaining good efficiency of the DAB converter. This paper presents a novel and effective approach to analyzing circulating current and ZVS conditions with respect to the voltage ratio.