ASTM D 3883-1990 机织织物的卷曲性或织缩的试验方法
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【英文标准名称】:TestMethodforYarnCrimporYarnTakeupinWovenFabrics
【原文标准名称】:机织织物的卷曲性或织缩的试验方法
【标准号】:ASTMD3883-1990
【标准状态】:作废
【国别】:美国
【发布日期】:1990
【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】:纺织材料;布;纺织试验;纱;纱线试验;机织物;试验;卷曲(纺织品);配料
【英文主题词】:testing;yarn;cloth;textiles;wovenfabrics;yarntesting;batching;textiletesting;crimping(textiles)
【摘要】:
【中国标准分类号】:W04
【国际标准分类号】:59_080_10
【页数】:4P;A4
【正文语种】:英语
【英文标准名称】:Short-circuitcurrentsinthree-phasea.c.systems-Calculationofcurrents
【原文标准名称】:三相交流系统内短路电流.电流的计算
【标准号】:BSEN60909-0-2001
【标准状态】:现行
【国别】:英国
【发布日期】:2001-10-26
【实施或试行日期】:2001-10-26
【发布单位】:英国标准学会(GB-BSI)
【起草单位】:BSI
【标准类型】:()
【标准水平】:()
【中文主题词】:电力设备;交流电流;故障电流;电流;三相电流;短路电流;低压设备;高压设备
【英文主题词】:Alternatingcurrent;Currents;Definition;Definitions;Electricpowernetworks;Electricalengineering;Electrically-operateddevices;Faultcurrents;Highvoltage;Lowvoltage;Mathematicalcalculations;Properties;Shortcircuitimpedance;Shortcircuits;Short-circuitcurrents;Symbols;Three-phasecurrent;Three-phasenetworks
【摘要】:ThispartofIEC60909isapplicabletothecalculationofshort-circuitcurrents:·inlow-voltagethree-phasea.c.systems·inhigh-voltagethree-phasea.c.systemsoperatingatanominalfrequencyof50Hzor60Hz.Systemsathighestvoltagesof550kVandabovewithlongtransmissionlinesneedspecialconsideration.ThispartofIEC60909establishesageneral,practicableandconciseprocedureleadingtoresults,whicharegenerallyofacceptableaccuracy.Forthiscalculationmethod,anequivalentvoltagesourceattheshort-circuitlocationisintroduced.Thisdoesnotexcludetheuseofspecialmethods,forexamplethesuperpositionmethod,adjustedtoparticularcircumstances,iftheygiveatleastthesameprecision.Thesuperpositionmethodgivestheshort-circuitcurrentrelatedtotheoneloadflowpresupposed.Thismethod,therefore,doesnotnecessarilyleadtothemaximumshort-circuitcurrent.ThispartofIEC60909dealswiththecalculationofshort-circuitcurrentsinthecaseofbalancedorunbalancedshortcircuits.Incaseofanaccidentalorintentionalconductivepathbetweenonelineconductorandlocalearth,thefollowingtwocasesmustbeclearlydistinguishedwithregardtotheirdifferentphysicalpropertiesandeffects(resultingindifferentrequirementsfortheircalculation):·line-to-earthshortcircuit,occurringinasolidlyearthedneutralsystemoranimpedanceearthedneutralsystem;·asingleline-to-earthfault,occurringinanisolatedneutralearthedsystemoraresonanceearthedneutralsystem.Thisfaultisbeyondthescopeof,andisthereforenotdealtwithin,thisstandard.Forcurrentsduringtwoseparatesimultaneoussingle-phaseline-to-earthshortcircuitsinanisolatedneutralsystemoraresonanceearthedneutralsystem,seeIEC60909-3.Short-circuitcurrentsandshort-circuitimpedancesmayalsobedeterminedbysystemtests,bymeasurementonanetworkanalyzer,orwithadigitalcomputer.Inexistinglow-voltagesystemsitispossibletodeterminetheshort-circuitimpedanceonthebasisofmeasurementsatthelocationoftheprospectiveshortcircuitconsidered.Thecalculationoftheshort-circuitimpedanceisingeneralbasedontherateddataoftheelectricalequipmentandthetopologicalarrangementofthesystemandhastheadvantageofbeingpossiblebothforexistingsystemsandforsystemsattheplanningstage.Ingeneral,twoshort-circuitcurrents,whichdifferintheirmagnitude,aretobecalculated:·themaximumshort-circuitcurrentwhichdeterminesthecapacityorratingofelectricalequipment;and·theminimumshort-circuitcurrentwhichcanbeabasis,forexample,fortheselectionoffuses,forthesettingofprotectivedevices,andforcheckingtherun-upofmotors.NOTEThecurrentinathree-phaseshortcircuitisassumedtobemadesimultaneouslyinallpoles.Investigationsofnon-simultaneousshortcircuits,whichmayleadtohigheraperiodiccomponentsofshort-circuitcurrent,arebeyondthescopeofthisstandard.Thisstandarddoesnotcovershort-circuitcurrentsdeliberatelycreatedundercontrolledconditions(short-circuittestingstations).ThispartofIEC60909doesnotdealwiththecalculationofshort-circuitcurrentsininstallationsonboardshipsandaeroplanes.
【中国标准分类号】:K04
【国际标准分类号】:17_220_01
【页数】:74P.;A4
【正文语种】:英语
基本信息
| 标准名称： | 犬人工授精技术规程 |
| 发布部门： | 黑龙江省质量技术监督局 |
| 发布日期： | 2008-07-07 |
| 实施日期： | 2008-08-07 |
| 首发日期： | |
| 作废日期： | |
| 出版社： | 中国标准出版社 |
| 出版日期： | 2008-08-07 |
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