Results 51 to 60 of about 1,585 (211)
New Techniques for Disconnector Switching VFT Mitigation in GIS [PDF]
Switching operations in a Gas Insulated Substations (GIS) generate very fast transient over voltages (VFTO) which are dangerous for the transformer and the system insulation because of their short rise time.
Abd-Allah, Mousa Awad Allah +2 more
core +1 more source
Nanocrystalline based Mitigation Technique for Very Fast Transient over Voltages in Gas Insulated Substations [PDF]
: in gas insulated substations, issue of very fast transient over voltages is very familiar problem because of its effects on live ultra-high voltage equipment.
et. al., R.Durga Rao,
core +1 more source
影响快速暂态过电压(very fast transient overvoltage,VFTO)因素很多,其中气体变电站(GIS)设备模型的选择对VFTO计算结果精确度的影响不可忽略。笔者采用考虑弧道电感特性的电弧电阻模型,结合国外某1 000 k V GIS变电站,详细计算了GIS内部的VFTO,分析了GIS内部关键设备处VFTO的极值。结果表明,用考虑弧道电感特性的电弧电阻模型模拟隔离开关的电弧的物理过程,进而对VFTO研究是适用的。最后还研究了入口电容、静态电感、GIS支路长度对VFTO的影响。
刘德东 +3 more
doaj
Conductance fluctuations in diffusive rings: Berry phase effects and criteria for adiabaticity
We study Berry phase effects on conductance properties of diffusive mesoscopic conductors, which are caused by an electron spin moving through an orientationally inhomogeneous magnetic field. Extending previous work, we start with an exact, i.e.
A. F. Morpurgo +27 more
core +1 more source
Universal basic education : an overall strategy of investment priorities for economic growth [PDF]
Includes bibliographical references (p. 27-28)
Boediono, McMahon, Walter W.
core
GIS变电站中隔离开关和断路器的操作会产生波头极陡并伴有高频振荡的快速暂态过电压(VFTO),对GIS设备运行的可靠性以及内外绝缘构成很大的威胁。现有研究表明GIS变电站拓扑结构对VFTO的幅值及频率特性有着较大的影响,而工程上主要关注VFTO沿线最大峰值的变化规律。为此从GIS变电站简化模型着手,分析研究VFTO的幅值以及频率特性随母线、分支母线长度变化的一般规律。在此基础上,通过ATP-EMTP电磁暂态仿真软件对青海某750 kV ...
蒋玲 +6 more
doaj
超高压GIS中隔离开关的开闭合可能产生特快速暂态过电压(Very Fast Transient Overvoltage, VFTO),而VFTO会对GIS及其相连设备造成破坏,因此如何削弱VFTO对其他设备的影响迫在眉睫。以某500 kVGIS变电站为研究对象,对隔离开关开闭过程进行仿真建模,模拟VFTO的产生并对其波形进行分析,随后对避雷器的抑制效果进行了仿真验证,然后对只加装阻塞特定频带的阻波器进行了特性仿真,最后对阻尼母线方法进行优化。通过对比不同措施下的VFTO仿真结果 ...
李佰霖 +3 more
doaj
GIS站操作隔离开关时会产生特快速暂态过电压(VFTO),对GIS站和相邻电气设备安全会造成严重威胁,必须采取措施对其进行抑制。用PSCAD软件对某550 kV典型GIS变电站建立了仿真模型,指出可通过抑制VFTO中主导频率分量以降低VFTO的能量,进而达到抑制VFTO峰值的目的。通过分析MOA位置与主导频率分量幅值之间的关系,确定了MOA的最佳位置,以最大程度降低VFTO。研究结果对于GIS站的设计、运维和设备保护具有一定的指导意义。
李宜, 张彼德
doaj
Anomaly Detection for Next-Generation Space Launch Ground Operations [PDF]
NASA is developing new capabilities that will enable future human exploration missions while reducing mission risk and cost. The Fault Detection, Isolation, and Recovery (FDIR) project aims to demonstrate the utility of integrated vehicle health ...
Brown, Barbara +7 more
core +1 more source
Boletín oficial de la provincia de León: Num. 57 (09/11/1896) [PDF]
Copia digital. Valladolid : Junta de Castilla y León.
León (Provincia). Diputación Provincial
core +9 more sources

