A Four-Phase Soft-Switching Boost Converter with a Single Auxiliary Switch

In this paper, a novel four-phase soft-switching boost converter is presented. The proposed converter only uses a single auxiliary circuit to turn o
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/off four main switches under soft-switching condition. Two loosely inverse-coupled inductors are used in four-phase interleaved boost converter to reduce the number of magnetic cores. The proposed four-phase converter extends the soft-switching range to duty cycles larger than 0.25. The main and auxiliary switches of the converter are turned on at zero voltage switching (ZVS) and zero current switching (ZCS) conditions, respectively. All the switches are turned off at ZVS condition. The operating stages of the converter are presented. A 10-kW four-phase converter prototype is built to verify the theoretical analysis of the converter. The experimental results at the duty cycles of 0.3 and 0.55 are presented.