太阳能飞行器能源系统中GaN变换器优化研究

RESEARCH ON OPTIMIZATION OF GaN-BASED CONVERTER IN SOLAR AIRCRAFT ENERGY SYSTEM

为实现太阳能飞行器能源系统的高效率和高功率密度,采用基于氮化镓(GaN)器件的四开关升降压(FSBB)变换器。首先提出一种变移相角控制策略,该控制策略可根据不同的输入电压范围,通过改变移相角来使电感电流纹波始终维持在此时工况下的最小值,同时保证电感以最小电流进行环流并兼顾软开关技术,进一步提高变换器的工作效率。然后对所提控制策略下的变换器进行建模,分析其稳定性,并通过对控制参数进行整定,完成变换器补偿网络的环路设计。最后搭建一台输入30~60 V,输出45 V/200 W的GaN FSBB变换器实验样机,验证变移相角控制策略的有效性。

In order to realize the high efficiency and high power density of the solar aircraft energy system,a four-switch Buck-Boost(FSBB)converter based on Gallium Nitride(GaN)devices is used.Firstly,a variable phase-shift angle control strategy is proposed.This control strategy can keep the inductor current ripple at the minimum value under the current operating conditions by changing the phase-shift angle according to the input voltage ranges,and at the same time ensure that the inductor current is circulating at the minimum value and take into account the soft switching technology,and further improve the working efficiency of the converter.Then,is modeled based on the converter under the proposed control strategy and its stability is analyzed.The loop design of the converter compensation network is completed by tuning the control parameters.Finally,an experimental prototype of a GaN-based FSBB converter with an input of 30-60 V and an output of 45 V/200 W was built to verify the effectiveness of the variable phase-shift angle control strategy.