A primary-side-assisted zero-voltage and zero-current switching DC-DC converter

Abstract

In this paper, a new primary-side-assisted zero-voltage and zero-current switching DC-DC converter with transformer isolation is proposed. The proposed DC-DC converter provides zero-current switching for the leading leg using a small auxiliary circuit consisting of two diodes and one auxiliary transformer whose power rating is about 10% of that of the main transformer. It has a load current control capability even at short circuit conditions using simple and robust structure. The auxiliary circuit can also be applied to three-level DC-DC converters that are promising for high-voltage and high-power applications. Operation of a 12 kW full bridge prototype designed for a welding application was tested and verified by experiments.