Results 61 to 70 of about 940 (189)
Gaoya dianqi, 2016 为了研究VFTO的特性及开关速度影响,建立高频电弧模型,建立全过程仿真模型,并研究MOA对VFTO抑制作用,文中设计建立了一个综合性的252 k V GIS设备VFTO试验回路。首先研究设计了试验回路的接线形式、设备选型,并结合仿真计算确定了母线长度、耦合电容值,预估了VFTO、VFTC的频率范围;然后研制了VFTO、VFTC、实时开距等测量系统,并研制了屏蔽、同步触发装置;最后对试验回路进行了调试,试验回路能产生典型的VFTO、VFTC波形,能精确测量VFTO、VFTC、开关实时开距 ...
段韶峰 +7 more
doaj
Validation of an Integrated Airframe and Turbofan Engine Simulation for Evaluation of Propulsion Control Modes [PDF]
The National Aeronautics and Space Administration (NASA) has developed independent airframe and engine models that have been integrated into a single real-time aircraft simulation for piloted evaluation of propulsion control algorithms.
Guo, Ten-Huei +4 more
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Detection of immature rice weevils, Sitophilus oryzae L. (Curculionidae, Coleoptera) by audio amplification [PDF]
, 1954 LD2668 .T4 1954 P47Master of ...
Pesho, George Robert.
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Gaoya dianqi, 2018 VFTO对设备的危害随着额定电压的提高而增大,超特高压VFTO的抑制对保障GIS变电站设备安全运行起到重要作用。文中提出一种阻尼母线的设计思想,该阻尼母线由镂空螺线管及与之并联的电阻组成,在工频下,对母线的绝缘性能、通流能力及力学性能不造成影响,在高频下,行波电流在电感端形成高电压,其两端阻尼电阻可在高压作用下吸收行波能量。文中建立某550kV典型GIS站VFTO计算模型,分别对该550kV GIS变电站检修转运行8种情况的40种操作方式下变电站各主要节点VFTO情况进行分析 ...
吴士普 +6 more
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Gaoya dianqi, 2006 根据GIS的结构特点,对一种带有并联电阻的隔离开关抑制VFTO的机理、作用进行了数值分析。通过研究可知, 由于隔离开关分合闸电阻有抑制VFTO的作用,GIS中所产生的VFTO的幅值不高,这对于GIS以及连接设备和二次控制装置的绝缘不会构成危害,但是GIS中的VFTO频率很高,对带有绕组的电气设备的绝缘水平,如变压器,会带来一定的影响。
阮全荣, 施围, 王亮
doaj
Defensive Publishing An Empirical Study [PDF]
Defensive Publishing denotes publication of an invention with the purpose of creating prior art, and thus preventing patents being granted on this invention. Although widely employed, it has hardly been investigated empirically.
Joachim Henkel, Stefanie Pangerl
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Simulation on VFTO by Phase-Selection Technology in Low Voltage [PDF]
Proceedings of the 2016 6th International Conference on Machinery, Materials, Environment, Biotechnology and Computer, 2016 Disconnector(DS) operations in GIS may generate very fasttransient overvoltage (VFTO), which is characterized by its high peak value, short rise time, and high frequencies. However,most studies on VFTO are based on statistical data, which cannot show the impact of different phases to VFTO.In this paper, we use a relay with MCU as the Phase-Selection ...
openaire +1 more source
Dianci bileiqi, 2012 目前,由于多种因素,金属氧化物避雷器在抑制特快速暂态过电压（VFTO）方面的应用有限。为了满足VFTO下避雷器的动态特性的需求,笔者介绍一种适用于VFTO计算的避雷器模型,由于避雷器电容效应,造成高频下残压和放电电流之间存在时间延迟,导致避雷器响应速度变慢。结合实例,对采用文中建议的模型和IEEE建议的模型下的VFTO做了仿真分析。结果表明 ...
曲振旭 +4 more
doaj
Modeling of impulsive propellant reorientation [PDF]
The impulsive propellant reorientation process is modeled using the (Energy Calculations for Liquid Propellants in a Space Environment (ECLIPSE) code. A brief description of the process and the computational model is presented.
Chato, David J. +2 more
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Development of a square wave response experimental device for VFTO sensor calibration [PDF]
, 2019 LAUREA MAGISTRALENegli switchgear a isolamento gassoso (in inglese gas insulated switchgear, GIS), operazioni di commutazione o guasti a terra possono causare sovratensioni transitorie molto veloci (in inglese very fast transient overvoltages, VFTO), e i
CHEN, SHUO
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