基于GaN器件的PFC设计

Design of PFC Based on GaN Devices

针对氮化镓GaN(gallium nitride)功率晶体管在AC-DC变换器当中的应用进行设计。首先,在了解GaN器件的基本特性后,通过LTspice仿真软件搭建了PFC电路,分析了GaN寄生参数对驱动电路的影响,得出的结果对PFC的PCB布局有明显的帮助,应尽量减小驱动器与GaN器件之间的距离,从而达到降低寄生电感的作用;然后,对高频Boost PFC电路进行了分析以及电感和电容的设计;最后,通过仿真验证了设计的正确性,并以UC3854为控制器搭建了1台2.5 kW 500 kHz的高功率密度PFC样机,测得的驱动波形稳定。

The application of gallium nitride(GaN) power transistor in AC-DC converter was designed. First, after the introduction of the basic characteristics of GaN devices, a power factor correction(PFC) circuit was built by simulation sof-tware LTspice to analyze the influences of parasitic parameters of GaN on the drive circuit. The results obtained were obviously helpful for the following PFC PCB layout, i.e., the distance between the driver and GaN devices should be minimized to reduce the influences due to parasitic inductance. Then, a high-frequency Boost PFC circuit was analyzed, and the corresponding inductance and capacitance were designed. Finally, this design was verified by simulations. In addition, a 2.5 kW 500 kHz high-power density PFC prototype was built with UC3854 as the controller, and the measured driving waveform was stable.