【英文标准名称】:TablesofConversionFactorsandEquivalentYarnNumbersMeasuredinVariousNumberingSystems
【原文标准名称】:各种支数标定制中测得的对等纱线支数表和换算系数表
【标准号】:ASTMD2260-1989
【标准状态】:作废
【国别】:美国
【发布日期】:1989
【实施或试行日期】:
【发布单位】:美国材料与试验协会(ASTM)
【起草单位】:ASTM
【标准类型】:()
【标准水平】:()
【中文主题词】:换算系数;支数标定制;纱;测量;换算表;纱线线密度测定;纺织材料
【英文主题词】:numberingsystem;conversionfactor;yarnlineardensitydetermination;conversiontables;yarn;measurement;textiles
【摘要】:
【中国标准分类号】:W04
【国际标准分类号】:59_080_20
【页数】:13P;A4
【正文语种】:英语


【英文标准名称】:Short-circuitcurrentsinthree-phasea.c.systems-Part3:Currentsduringtwoseparatesimultaneousline-to-earthshortcircuitsandpartialshort-circuitcurrentsflowingthroughearth
【原文标准名称】:三相交流系统中的短路电流.第3部分:两个独立的同时对地短路、部分短路电流流入大地情况下的电流
【标准号】:IEC60909-3-2003
【标准状态】:作废
【国别】:国际
【发布日期】:2003-09
【实施或试行日期】:
【发布单位】:国际电工委员会(IX-IEC)
【起草单位】:IEC/TC73
【标准类型】:()
【标准水平】:()
【中文主题词】:双线对地短路;线路对地短路;单相电路;电气设备;定义;数学计算;电气工程;短路电流;短路阻抗;短路
【英文主题词】:Definition;Definitions;Doubleline-to-earthshort-circuits;Electricpowernetworks;Electricalengineering;Electricalequipment;Faultcurrents;Highvoltage;Line-to-earthshort-circuits;Lowvoltage;Mathematicalcalculations;Multilingual;Shortcircuitimpedance;Shortcircuits;Short-circuitcurrents;Single-phasecircuits;Symbols;Three-phasecurrent;Three-phasenetworks
【摘要】:ThispartofIEC60909specifiesproceduresforcalculationoftheprospectiveshort-circuit.currentswithanunbalancedshortcircuitinhigh-voltagethree-phaseACsystemsoperatingatnominalfrequency50Hzor60Hz,i.e.a)currentsduringtwoseparatesimultaneousline-to-earthshortcircuitsinisolatedneutralorresonantearthedneutralsystems;b)partialshort-circuitcurrentsflowingthroughearthincaseofsingleline-to-earthshortcircuitinsolidlyearthedorlow-impedanceearthedneutralsystems.Thecurrentscalculatedbytheseproceduresareusedwhendetermininginducedvoltagesortouchorstepvoltagesandriseofearthpotentialatastation(powerstationorsubstation).Thisstandarddoesnotcover:a)short-circuitcurrentsdeliberatelycreatedundercontrolledconditionsasinshort-circuittestingstations,orb)short-circuitcurrentsintheelectricalinstallationsonboardshipsoraeroplanes,orc)singleline-to-earthfaultsinisolatedorresonantearthedsystems.Theobjectofthisstandardistoestablishpracticalandconciseproceduresforthecalculationofline-to-earthshort-circuitcurrentsduringtwoseparatesimultaneousline-to-earthshortcircuitsandpartialshort-circuitcurrentsthroughearthfromelectricalinstallations,leadingtoconservativeresultswithsufficientaccuracy.Forthispurpose,thecurrentisdeterminedbyconsideringanequivalentvoltagesourceappliedattheshort-circuitlocationwithallothersourcessettozero.Theprocedureissuitablefordeterminationbymanualmethodsordigitalcomputation.ThisstandardisanadditiontoIEC60909-0.Generaldefinitions,symbolsandcalculationassumptionsrefertothatpublication.Specialitemsonlyaredefinedorspecifiedinthisdocument.Thisdoesnotexcludetheuseofspecialmethods,forexamplethesuperpositionmethod,adjustedtoparticularcircumstances,iftheygiveatleastthesameprecision.AsstatedinIEC60909-0,short-circuitcurrentsandtheirparametersmayalsobedeterminedbysystemtests.Thecalculationoftheshort-circuitparametersbasedontherateddataoftheelectricalequipmentandthetopologicalarrangementofthesystemhastheadvantageofbeingpossiblebothforexistingsystemsandforsystemsattheplanningstage.
【中国标准分类号】:K04
【国际标准分类号】:17_220_01
【页数】:72P;A4
【正文语种】:英语