一种适用于卫星姿态控制的移相全桥变换器研究OA

Phase-shifted full-bridge(PSFB)converters boasts have advantages such as simple control,soft-switching operation of switching devices and small size,which are widely applied in the field of secondary power conversion for aeronautics and astronautics.However,for some aeronautics and astronautics loads that require wide-range adjustment of the output power of power supplies,the PSFB converter has drawbacks including large circulating current in bridge arms under light load and low operating efficiency.In allusion to the efficiency optimization issues including low light-load efficiency of PSFB converters and the inability of the radiation-hardened analog controller UC1875J to realize multi-mode control,on the basis of the traditional phase-shift control strategy,a method of hybrid control combining PWM mode and variable frequency mode based on analog circuit is proposed,which can automatically make judgments and switch to the corresponding control mode under light-load conditions of the output load.An engineering prototype with a power rating of 300 W and an output voltage of 46 V is built to verify the proposed method.The experimental results demonstrate that the proposed hybrid control method can improve the light-load efficiency of the converter,and its light-load efficiency is better than traditional phase-shift control after actual measurement and comparison of different mixing mode control methods.The efficiency of the prototype at 0.5 A load is increased from 66%to 71%,while the converter can maintain stable operation across the entire load range with a peak efficiency of 85%.