Results 51 to 60 of about 940 (189)
Dianci bileiqi, 2023 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
The influence of VFTO on SCSR windings with an equivalent PEEC model
International Journal of Electrical Power & Energy Systems, 2019 Abstract Stepped Controlled Shunt Reactors (SCSRs) have advantages of flexible control and reliable compensation and are likely to become widely used in Ultra-High-Voltage/Extra-High-Voltage (UHV/EHV) transmission systems. Very fast transients that occur in such systems will generate a Very Fast Transient Overvoltage (VFTO) in the SCSR.
Hongshun Liu +5 more
openaire +1 more source
Dianci bileiqi, 2020 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
Anomaly Detection for Next-Generation Space Launch Ground Operations [PDF]
, 2010 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
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Study on transient voltage distribution characteristics of transformer windings [PDF]
, 2020 Very fast transient overvoltage (VFTO) with large waveform steepness and high amplitude can cause great harm to winding insulation of transformers and other equipment connected to it.
Xie Yu, Xu Jianwen, Xu Tao, Zang Ying
core +1 more source
Dianci bileiqi, 2020 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
New Techniques for Disconnector Switching VFT Mitigation in GIS [PDF]
, 2014 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
Gaoya dianqi, 2020 深入开展了VFTO在GIS罐体内部电磁传播特性的研究,对GIS的VFTO辐射电场测量方法具有一定的工程意义。为此,文中搭建了220 kV GIS的有限元仿真模型,开展了不同影响因素下VFTO电磁波在GIS中传播的特性的仿真计算分析。通过研究得到了基于GIS多影响因素的VFTO电场峰值还原计算公式,得到了不同因素对电磁波传播过程中幅值、波形以及传播时间的影响规律,对开展VFTO的高频电场的测量方法研究具有一定的参考价值。
洪志湖 +6 more
doaj
Ceramic powder for sintering materials [PDF]
Surface activity of ceramic powders such as MgO and Al2O3, for use in sintering with sp. emphasis on their particle size, shape, particle size distribution, packing, and coexisting additives and impurities are ...
Akiya, H., Saito, A.
core +1 more source
Different Approaches of Numerical Analysis of Electromagnetic Phenomena in Shaded Pole Motor with Application of Finite Elements Method [PDF]
, 2010 In this paper is used Finite Element Method-FEM for analysis of electromagnetic quantities of small micro motor – single phase shaded pole motor-SPSPM.
Gustafsson, Emil, Nordström, Fredrik
core