共查询到19条相似文献,搜索用时 140 毫秒
1.
航天器浮动电位的初步分析 总被引:1,自引:0,他引:1
为了研究表面充电引起的浮动电位情况,我们采用等效电容的方法分析了近赤道低轨道高度条件下航天器的等效电容及充电时间问题,初步总结了浮动电位对航天器可能产生的影响。根据计算结果可以认为在低轨道等离子体环境中航天器会达到浮动电位的平衡状态。
相似文献
相似文献
2.
从带电表面微元出发,通过求解泊松方程,得到带电介质平板表面邻近空间静电势的解析表达式,建立介质表面电位-介电常数模型,求得了带电介质平板表面电位、表面带电量和介质介电常数三者之间的关系式。结合典型的航天器表面介质材料带电案例,对此类圆盘结构介质平板带电问题进行了仿真分析,结果表明,在介质材料表面电位一定的情况下,表面电荷激发的空间静电势值随距离的增大而减小,并且距离介质表面越近,电势的空间变化率越大;在介质材料带电量相等的情况下,介质表面电位随着介质介电常数的增大而减小,并逐渐趋于一个稳定值,所以在一定范围内选择介电常数较大的介质材料可以降低介质的表面电位,减小介质间发生静电放电的几率。 相似文献
3.
4.
5.
文章以空间相机应用为目的,在分析第二代红外探测器驱动电压与输出信号之间相关性的基础上,以某型号第二代红外探测器驱动电压供电电路设计为例,采用高稳定基准电压芯片和低噪声低频运算放大器作为核心器件,提出了以负反馈或电压跟随的电路形式稳定驱动电压供电的方案,并对该方案进行了仿真分析与实验验证.测试结果证实该方案可行有效,能满... 相似文献
6.
木星为太阳系内少有的强磁场行星,其等离子体环境十分恶劣,可对木星探测器造成严重的表面充电效应。文章采用有限元方法,借助COMSOL仿真软件,对航天器表面充电现象进行三维仿真,结合NASCAP-2k以及SPIS软件对比验证了GEO表面充电效应的模拟结果,证明了该仿真方法的有效性。对航天器在木星极光等离子体环境下的表面充电现象仿真分析结果表明,在木星背景等离子体环境中15RJ处,航天器表面充电电位较低,仅为平均-80 V左右;而在木星极光等离子体中,航天器表面充电电位最高可以达到-36.7 k V,CERS等材料表面充电电位差最大可以达到-16 k V,具有较高的放电风险。 相似文献
7.
8.
9.
10.
一种新型航天器──穿入式星体探测器张万周俄罗斯制定的火星-96计划中。要求研制一种全新的航天器──穿入式太阳系星体探测器(见本刊1995年第8期第14页和1996年第4期第35页)。现对这种探测器及俄的应用设想作一介绍。一、穿入式探测器的由来人类通过... 相似文献
11.
12.
13.
14.
一种宽频带圆极化微带天线的设计 总被引:2,自引:0,他引:2
设计了一种宽频带圆极化微带天线。其结构为双层介质与空气层结合,辐射贴片为单个圆形金属片,通过电容耦合馈电的两个圆形金属片与威尔金森功分器相接,功分器的两个端口输出的功率幅度相同,相位相差90°。天线的3dB极化带宽为56%,VSWR<2的驻波比带宽为64%,增益在52%的带宽范围内变化在1dB以内。天线的远场方向图极化特性在35%的带宽范围内较好。 相似文献
15.
16.
为了研究空间微小碎片碰撞对航天器的影响,国内外研制了各种类型的微小碎片加速器。文章简要介绍了一种很有前景的静电式微小碎片加速器及其关键部件的工作原理、结构特点及适用范围等。 相似文献
17.
18.
19.
《中国航天(英文版)》2019,(2)
A 28 V-half-regulated power bus topology and an integrated PCDU(Power Conditioning and Distribution Unit) were adopted to meet the energy demand for the Chang'e 4 relay satellite. This paper first introduces the mission features and composition of the PSDS(Power Supply and Distribution System) for the Chang'e 4 relay satellite. Due to this satellite's unusual orbit, operational mode and project restrictions, special analysis and design was conducted on the PSDS from the perspective of weight-reduction, power management, and reliability and so on. Extreme low temperature storage of SA(Solar Array) was considered and how the antenna affects the SA was analyzed. A new kind of high-specific-energy 45 Ah(Ampere-hour) battery cell was used for the first time. To make sure that the satellite would successfully pass the long shadow zones, a 100% DOD(Depth of Discharge) experiment was carried out on the battery. Since the sunlight is almost always available and there are very few times for the battery to charge or discharge, battery care to extend its lifetime is also discussed. PCDU is a device that integrates power conditioning and power distribution in one unit. The PCDU on Chang'e 4 relay satellite can output more power with less weight because of the adoption of a 28 V-half-regulated power bus topology which was also used for the first time and used lighter material for its mechanical framework. Experiment under low temperature on PCDU was conducted as well and a hot backup equalizing charge technique which is beneficial to keep performance of the battery is illustrated. The power distribution module, which is a module of PCDU, enhances the power utilization security by utilizing a static impedance measurement and build-in-test to avoid possible short circuits. As for EED(Electrical Explosive Device) module, a protection plug was specially designed and three switches with different functions were connected in series to prevent the EED from exploding by error. In addition, the allowable minimum EED bus voltage for each EED was evaluated in case of low battery voltage caused by the possible postponement of the launching time. Complete verification experiments on the ground were conducted to confirm the correctness of the design and on-orbit test data conformed to the expected results and theoretical calculation. The power supply and distribution system has been working normally since the day the Chang'e 4 relay satellite was launched into space. 相似文献