Efficiency Improvement of Current-Fed DAB Converter by Triangular Current Mode for Wide Voltage Applications

This paper proposes a control method of a Current-Fed DAB converter by Triangular Current Mode (TCM). The proposed method extends the Zero-Voltage-Switching (ZVS) range for wide input/output voltage variations. In addition, the proposed method reduces the inductor RMS current compared with the typical DAB converter. The validity of the proposed method is demonstrated by a 2-kW prototype circuit. As a result, the maximum efficiency of the Current-Fed DAB converter with the proposed method is 97.5% at rated load conditions. Moreover, the efficiency of the Current-Fed DAB converter with the proposed method is 97.2% when the input voltage is varied by 50% from the nominal condition, then the loss is reduced by 52.5% compared to that of the conventional method.