标准名称：	旋光仪
中标分类：	仪器、仪表 >> 光学仪器 >> 电子光学与其他物理光学仪器
替代情况：	JB 482-64
发布部门：	机械电子工业部
发布日期：	1991-07-16
实施日期：	1992-07-01
首发日期：	1900-01-01
作废日期：	1900-01-01
提出单位：	上海光学仪器研究所
归口单位：	上海光学仪器研究所
起草单位：	上海光学仪器研究所
出版社：	机械行业出版社
出版日期：	1992-07-01
页数：	6页

本标准规定了旋光仪产品分类、技术要求、试验方法、检验规则、标志、包装、运输、贮存等。
本标准适用于测定旋光物质旋光度的旋光仪。

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【英文标准名称】:Short-circuitcurrentsinthree-phasea.csystems-Currentsduringtwoseparatesimultaneousline-to-earthshort-circuitsandpartialshort-circuitcurrentsflowingthroughearth
【原文标准名称】:三相交流系统中的短路电流.两条独立线路同时对地短路和部分短路电流流入大地时的电流
【标准号】:BSEN60909-3-2010
【标准状态】:现行
【国别】:英国
【发布日期】:2010-04-30
【实施或试行日期】:2010-04-30
【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】:定义(术语);双线接地短路;电网;电气工程;电气设备;电学;故障电流;高电压;线路接地短路;低电压;数学计算;架空线;还原比率;短路阻抗;短路;短路电流;单相电路;符号;三相电流;三相电力网
【英文主题词】:Definitions;Doubleline-to-earthshort-circuits;Electricpowernetworks;Electricalengineering;Electricalequipment;Electricity;Faultcurrents;Highvoltage;Line-to-earthshort-circuits;Lowvoltage;Mathematicalcalculations;Overheadpowerlines;Reductionratio;Shortcircuitimpedance;Shortcircuits;Short-circuitcurrents;Single-phasecircuits;Symbols;Three-phasecurrent;Three-phasenetworks
【摘要】:ThispartofIEC60909specifiesproceduresforcalculationoftheprospectiveshort-circuitcurrentswithanunbalancedshortcircuitinhigh-voltagethree-phasea.c.systemsoperatingatnominalfrequency50Hzor60Hz,i.e.:a)currentsduringtwoseparatesimultaneousline-to-earthshortcircuitsinisolatedneutralorresonantearthedneutralsystems;b)partialshort-circuitcurrentsflowingthroughearthincaseofsingleline-to-earthshortcircuitinsolidlyearthedorlow-impedanceearthedneutralsystems.Thecurrentscalculatedbytheseproceduresareusedwhendetermininginducedvoltagesortouchorstepvoltagesandriseofearthpotentialatastation(powerstationorsubstation)andthetowersofoverheadlines.Proceduresaregivenforthecalculationofreductionfactorsofoverheadlineswithoneortwoearthwires.Thestandarddoesnotcover:a)short-circuitcurrentsdeliberatelycreatedundercontrolledconditionsasinshortcircuittestingstations,orb)short-circuitcurrentsintheelectricalinstallationsonboardshipsoraeroplanes,orc)singleline-to-earthfaultcurrentsinisolatedorresonantearthedsystems.Theobjectofthisstandardistoestablishpracticalandconciseproceduresforthecalculationofline-to-earthshort-circuitcurrentsduringtwoseparatesimultaneousline-to-earthshortcircuitsandpartialshort-circuitcurrentsthroughearth,earthwiresofoverheadlinesandsheathsorshieldsofcablesleadingtoconservativeresultswithsufficientaccuracy.Forthispurpose,theshort-circuitcurrentsaredeterminedbyconsideringanequivalentvoltagesourceattheshort-circuitlocationwithallothervoltagesourcessettozero.Resistancesofearthgridsinstationsorfootingresistancesofoverheadlinetowersareneglected,whencalculatingtheshort-circuitcurrentsattheshort-circuitlocation.ThisstandardisanadditiontoIEC60909-0.Generaldefinitions,symbolsandcalculationassumptionsrefertothatpublication.Specialitemsonlyaredefinedorspecifiedinthisstandard.Thecalculationoftheshort-circuitcurrentsbasedontherateddataoftheelectricalequipmentandthetopologicalarrangementofthesystemhastheadvantageofbeingpossiblebothforexistingsystemsandforsystemsattheplanningstage.Theprocedureissuitablefordeterminationbymanualmethodsordigitalcomputation.Thisdoesnotexcludetheuseofspecialmethods,forexamplethesuper-positionmethod,adjustedtoparticularcircumstances,iftheygiveatleastthesameprecision.AsstatedinIEC60909-0,short-circuitcurrentsandtheirparametersmayalsobedeterminedbysystemtests.
【中国标准分类号】:K04
【国际标准分类号】:17_220_01;29_020;29_240_20
【页数】:60P.;A4
【正文语种】:英语