Implementation of Phase Shift Ful1-Bridge Converter Using GaN FET for EV Charger

With the popularity of electric vehicles, there are more and more battery charging devices for electric vehicles, and the full bridge converter is suitable for medium and high power occasions. Therefore, the full bridge converter has become the research goal. Moreover, gallium nitride transistors based on the third generation wide-band gap semiconductor materials have more advantages than MOSFETs. Therefore, the application of gallium nitride transistor instead of MOSFET in electric energy converter has become an important research topic. In this paper, the full bridge architecture is adopted, and the phase-shift modulation is used to make the converter have zero voltage switching, and the gallium nitride transistor is used as the power switch to improve the efficiency of the converter. The proposed converter has the following characteristics: (1) It can be applied to electric vehicle charger and has zero voltage switching to improve the efficiency of the converter (2) Gallium nitride transistor is used for switching to improve the overall efficiency of the converter (3) The efficiency of the converter under light load can be significantly improved by using gallium nitride transistor. In this paper, two sets of phase shift full-bridge converters using gallium nitride transistor and MOSFET are completed and compared. The input voltage range is 300 V $\sim$ 350V, the output voltage is 96 V, the rated output power is 480 W, and the maximum efficiency is 96.15%. At light load, the efficiency of gallium nitride circuit is 6.84% higher than the circuit using MOSFET.