Abstract:

The performances in circuit loss of an interleaved dual Boost high power derect-curent to derectcurent (DC-DC) converters were analyzed by using Si devices or/and SiC devices in a fuel cell vehicle to regulate and control the output voltage and output power. The circuit losses and efficiency in the whole SiC devices (i.e. SiC Metal-Oxide-Semiconductor Field-Effect Transistor, MSOFET and SiC diode) converter, hybrid devices (i.e. SiC MOSFET and Si diode) converter and the whole Si devices (i.e. Si Insulated Gate Bipolar Transistor, IGBT and Si diode) converter were compared base on circuit loss numerical calculation and efficiency simulation. The results show that the Si IGBT losses are 3 times for switching on and 10 times for switching off as that of SiC MOSFET and the efficiencies of All-SiC devices are 1%~3.1% higher than All-Si devices in different conditions. Therefore, the SiC devices can improve the power density, reliability and efficiency of the power system for high power DC-DC converters.

Key words: fuel cell vehicles, DC-DC converter, interleaved dual Boost circuit, SiC MOSFET (metal-oxidesemiconductor field-effect transistor), Si IGBT (insulated gate bipolar transistor), circuit loss