一种直接入轨卫星变轨阶段的供电方案

相比传统的卫星自身变轨方式,直接入轨方式下卫星的主动段时间将延长到4~5h。为解决卫星直接入轨过程中由于主动段时间大大加长,导致卫星电能需求的增加,以及电源系统配置不必要的质量增加的问题,文章提出了一种在发射和变轨阶段通过运载火箭上面级向卫星供电的方案,即在上面级上增加了一套独立的一次性电源系统。该系统与卫星自身电源系统相结合,在发射和变轨期间优先使用,卫星自身电源根据负载用电情况自主介入,能很好地解决卫星直接入轨方式下主动段的电能需求问题。

Studies of Influence Factors on Temperature Control Precision of Shape-stabilized Phase Change Materials

Shape-stabilized phase change materials which can be used to resolve the problems such as traditional phase change material leakage and heat transfer performance, have a good applica- tion prospect in areas such as electronic temperature control, however, the temperature control precision are greatly effected by phase change material physical parameters, external environment and other factors. By setting up a heat transfer model of the shape-stabilized phase change materi- als, this paper analyzes the influence of various parameters on the temperature control precision on the basis of experimental study and numerical analysis. The results of the study show that thermal conductivity of the shape-stabilized phase change materials has great influence on temper- ature control precision, which rises with the increase of the thermal conductivity~ temperature control precision is decreases with the increase of the heating power. When the thermal conduc- tivity is less than 1.76W. m-1 .K-1 ,the temperature control precision is reduced obviously. And it reduces with the increase of heating power,with the increase of width of phase transition tem perature and the thickness of phase change materials.