Soft-Switching performance of Dual Active Bridge DC-DC Converter

This paper presents the Zero-Voltage Switching (ZVS) performance of Dual Active Bridge (DAB) DC-DC converter for high power density aerospace applications. Switching transitions of the transistor occurring in favorable conditions such as device zero-voltage or zero-current is called as soft-switching. The benefits of soft-switching are reduced switching losses, switch stress, low electromagnetic interference and easier thermal management. These are essential features for high frequency operation of power converters. The DAB converter topology has been chosen as it features high power density, high efficiency, bidirectional power flow capability, inherent soft switching, galvanic isolation and low number of passive components. Hence the converter is a candidate for high power density aerospace applications. For performance evaluation, input side of the converter is connected to the high voltage (HV) DC bus and output side of the converter is connected to the low voltage (LV) ultracapacitor. A DAB converter is modelled using SABER software. SABER simulation results under ZVS verify the soft-switching performance of the DAB DC-DC converter. Key-Words: DC-DC converter, Zero-voltage switching, Dual active bridge topology, High power density, Soft-switching operation, Galvanic isolation.