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电容器涌入电流的抑制,是TSC式消弧线圈设计中要考虑的一个重要问题.文章对TSC式消弧线圈的工作原理和运行特点进行了分析,对电容器投入电网运行时的涌入电流分两种情况进行了研究,得出了TSC式消弧线圈涌入电流的计算方法.最后给出抑制涌流的两种方法-零压差投入和串联扼流线圈. 相似文献
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将二次电源的浪涌电流抑制问题提升到"最佳抑制问题"讨论。目的是寻找一种浪涌电流,它不仅满足一次电源要求的限制浪涌电流幅值,二次电源设计限定的完成浪涌过程时间,而且使浪涌抑制管在这过程中产生的最大瞬时功率值最小。本文给出了满足这些要求的最佳浪涌电流的解析式,对常用的线性浪涌电流抑制作了分析和评述,为解决这类问题提供了新的思路。 相似文献
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一种卫星用浪涌电流抑制电路的设计与分析 总被引:1,自引:0,他引:1
为防止容性设备产生的浪涌电流对整星供电系统的危害,提出一种卫星上常用的浪涌电流抑制电路,并对该电路的设计进行详细说明,最后,通过具体案例说明浪涌电流抑制电路的重要性和有效性。 相似文献
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潜射导弹离筒后海水倒灌效应数值分析 总被引:3,自引:0,他引:3
针对潜射导弹水下垂直发射离筒后海水倒灌涌入引起的冲击问题,利用数值计算方法对其进行研究。基于水气两相流动的基本控制方程、VOF模型和动网格技术,实现了考虑弹体运动的水下发射多相流动问题求解。以此为基础,对潜射导弹垂直发射的水下运动和海水涌入过程进行了数值模拟,进而对影响涌入海水冲击压强的因素进行分析,以寻求降低海水涌入冲击压强的有效措施。模拟和分析结果表明,海水倒灌涌入会对发射筒结构产生显著的压强冲击;在发射筒底部附近增加局部挡流板,可有效降低涌入海水的冲击效应。 相似文献
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航天器DC-DC开关二次电源作为星上功率电子设备,既是重要的电磁干扰源,也是易受电磁干扰的设备,其电磁兼容性设计尤为重要.开关电源差模滤波器对传导干扰有着较好的抑制作用,是开关电源不可或缺的组成部分,其稳定性、可靠性和有效性是设计的关键.文章主要讨论了开关电源在低频干扰模式下的负阻抗特性,以及负阻抗模式下的不稳定原理和稳定原则.基于滤波器输入电压干扰抑制和反射电流干扰抑制的互偶原理,提出了LC滤波器参数设计流程.设计了一种基于滤波电容器电压波动幅值的LC滤波器参数计算方法,并给出了合理的滤波器失配裕量.该方法具有稳定性高和可靠性高的特点,特别适用于宇航二次电源高可靠需求.最后,依据上述流程和方法设计了一个开关电源模块,并顺利通过了EMC测量验证. 相似文献
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用添加剂抑制固体火箭发动机排气二次燃烧的研究 总被引:3,自引:0,他引:3
介绍了采用化学添加剂抑制固体火箭发动机排气二次火焰的实验研究。10种化学添加剂的实验结果表明,其中5种对二次火焰有抑制作用。进而又以它们对一种双基推进剂和一种中能无烟推进剂装药发动机羽流二次火焰的抑制效果,以及羽流对电磁波衰减的影响,进行了实验验证。另外,还用附加药片法对添加剂的消焰效果做了实验,证明这是一种简便实用又不影响推进剂燃烧性能的抑制剂施加方法。 相似文献
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高频地波雷达的海上目标探测能力与电离层杂波的抑制效果息息相关,而电离层杂波的复杂性与变化多样性又为抑制带来了难题。为实现电离层杂波的抑制,分析了电离层杂波的混沌特性,在此基础上提出一种基于改进粒子群算法优化小波神经网络的抑制方法,解决了粒子群算法易早熟和易陷入局部最优的缺点;提出一种自适应概率变异的策略,丰富了种群多样性,使得整个迭代过程中粒子群能够跳出当前最优,寻得全局最优。实测实验表明,基于改进粒子群算法优化的小波神经网络(PSO-WNN)能够基本预测电离层杂波的数值,进行电离层杂波的抑制,有效改善了信噪比,对电离层杂波的抑制研究具有重要意义。 相似文献
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E.H. Lemke 《Acta Astronautica》1985,12(9):647-659
The force on a coil moving with a high-speed parallel to a conducting grid consisting of parallel tubes is investigated. The coil performs a rebound motion or an oscillatory heave motion when pressed toward the grid by reactive on-board engines. The coil is approximated by two parallel wires moving parallel to the grid tubes. The corresponding electrodynamic problem is two dimensional and is solved by expansions in terms of Bessel functions. Expressions are derived for the lift and drag force as well as the heat generated in the tubes in the limit of strong skin effect. The dependence on the grid spacing is analysed in the approximation of no mutual inductance between the tubes. Two specific applications are a shunt deflecting the coil, and a funnel leading to multiple reflection. Finally, the varying magnetic flux threading the coil is considered and the thermal load of the coil is estimated. 相似文献
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Based on the analysis of solar events on August 18, 1995 (SN/C1.9 limb event) and September 23, 1998 (3B/M6.9 disk event) we suggest a new scenario of a solar flare with a surge in which the return motion of a surge is a cause of additional energy release and formation of a second system of solar flare ribbons. Observations in Hα line and data on X-ray emission fluxes in the range 1–8 Å and 0.5–4 Å are supplemented for the second case by the data in line 1550 Å. The scenario specifies two stages of development. During the first one the energy release proceeds in the current layer, which makes provisions both for acceleration of eruption upward from the solar surface and for the flare itself, including flare region heating, and radiation and thermal conductance losses. The second stage of the flare is supplied with energy due to a fall of the surge substance onto the chromosphere. The second pair of flare ribbons observed at this stage is suggested as a chromospheric criterion of realization of this scenario for disk flares. The energy released during the first stage of the flare on September 23, 1998 was equal to ~3 · 1031 erg. Its part consumed on flare processes is about ~0.5 · 1031 erg. The remaining part representing the eruption energy is consistent in order of magnitude with a calculated value of the flare energy on the second stage, which does not contradict the suggested scenario. Early recognition of such a scenario for flares on the disk can be used for prompt space weather forecast. In particular, a flare with a surge allows one to predict the absence of a bright core in a coronal mass ejection. 相似文献
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This paper analyzes superconducting (SC) coils technology to improve satellite electric propulsion. SC magnets can generate very high magnetic fields with extremely low ohmic losses, low electric power and PCU weight. Moreover, the weight of SC magnet coils is quite low compared with conventional or permanent magnets capable of producing the same field strength. For instance, to obtain a 0.4 T magnetic field strength, typical of applied field magnetoplasmadynamic thrusters (AF-MPD), based on the Lorentz force, and with thrust in the range of 1 N, this paper shows that only a 40 g coil SC weight is needed, whereas an equivalent field copper winding would weigh about 36 kg. Using SC technology it is shown that the limited magnetic induction provided by a permanent magnet may be raised and also that it is possible to obtain high magnetic fields (of order of several Tesla) with fewer turns, drastically reducing coil volume, weight and complexity compared to conventional winding.
Superconductivity at low temperature (LTSC) requires liquid helium at 4.2 K to produce very high current densities: the thermal analysis in this paper shows that, depending on satellite and thruster, high temperature superconductors (HTSC) wires are sometimes better than LTSC because these can support lower current densities but with a critical superconductivity temperature higher than for LHe, requiring LN2 at 77 K, easier to maintain during the whole mission.
Finally, this paper shows that implementing SC cryogenic technology on a satellite can be achieved with current active coolers technology. 相似文献
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