Investigation of a bidirectional DC/DC converter with zero-voltage switching operation for battery interfaces

Abstract

This paper proposes a bidirectional DC-DC converter with soft-switching capabilities. The main characteristic of this converter is that it can be operated in both boost and buck modes. The major advantages of this converter are high efficiency and reduced switching loss in high-power and high-voltage applications. The soft-switching capability is obtained by additional dual auxiliary resonant circuits connected to the conventional non-isolated bidirectional DC-DC converter. Except for the auxiliary switches, all main switches turn on with zero-voltage switching in this proposed bidirectional DC-DC converter. The auxiliary switches turn off with zero current transition. The principle of operation, theoretical analysis and experimental results of a 175 V/385 V bidirectional DC-DC converter at 2 KW output power with switching frequency of 50 kHz are provided. The experimental results verified the zero-voltage switching operation for boost and buck modes with efficiencies 96.5% and 96%, respectively, at full load.