Highly Efficient, and Compact ZVS Resonant Full Bridge Converter using 1200V SiC MOSFETs

The next generation (Gen2) of Silicon Carbide (SiC) devices is used in a Zero Voltage Switching (ZVS) converter application. A 1200V 160mohm SiC MOSFET from Cree Inc. is used to design a high frequency ZVS LLC resonant Full Bridge (FB) DC/DC converter. With the outstanding advantages of SiC MOS, which has lower junction capacitance and low onstate resistor compared to Si device, the resonant converter can achieve high frequency and high efficiency, thus increasing the power density with fewer components and reducing total cost. An 8KW prototype of LLC resonant full bridge converter with high modulated switching frequency range from 200KHZ to 400KHZ is developed to demonstrate how the SiC MOS can help achieve the highest performance for a soft-switching DC/DC converter with the maximum efficiency measured at 98.3%. These types of converters can be commonly used in three-phase industrial power supply applications, e.g., telecom or server power converter, High Voltage DC (HVDC) system, inductive heating, or Electric Vehicle (EV) charger.