低压电网质量LVNQ

34LowVoltageProductsCNABB/LV/TC/0110-1999A/W7/998/2/00,10:11PM342LowVoltageProductsCONTENTSDescriptionLowVoltageNetworkQualityCapacitorConstructionFixedCapacitorUnitsCLMDProductDescriptionTechnicalSpecificationProductRangeandOrderingDataAutomaticCapacitorBankCLMH-HKProductDescriptionTechnicalSpecificationProductRangeandOrderingDataAutomaticCapacitorBankCLMTCompactWall-MountedorFreeStandingSystemProductDescriptionTechnicalSpecificationProductRangeandOrderingDataDimensionsCLMDCLMH-HKCLMTCapacitorApplicationManualAppendixHarmonicandCapacitorPage347891112131415161718181925A/W7/998/2/00,10:00PM23LowVoltageProductsInternallyProtectedElements(IPE)ABB’ssequentialprotectionsystemfeaturingourpatentedInternallyProtectedElement(IPE)designprovidesincreasedprotectiontofacilitiesandpersonnelnotavailablefromothercapacitordesigns.Thisprovendesignallowsforself-healingthroughoutthelifeofthecapacitortoinsurethemaximumlengthofreliableserviceandstillprovideshortcircuitprotectionineachelementwhenself-healingcannolongercontinue.Thisisaccomplishedbyacombinationofuniquewindingconstructionandaninternalfuselink(SeeFig.3)withineachelementwhichsafelyandselectivelydisconnectseachindividualelement.ABBcapacitorsdonotrelyonmechanicalpressureinterruptersandadditionallinefuseswhichhavedisadvantagesassociatedwiththattypeofconstruction.LowVoltageNetworkQualityAdvanceddesignfeaturesinherentinallABBcapacitorproductsinclude:•Drytypedesign•Self-healingelements•InternallyProtectedElements(IPE)DrytypedesignAllABBlowvoltagecapacitorsutilizeelementsthatarecompletelydryandcontainnofreeliquid.Self-healingelementsABBcapacitorsareconstructedfromacompletelydrymetallizedpolypropylenefilm.Ashortcircuitbetweenelectrodes(SeeFig.1)isshortlived.Theelectrodeisinstantaneouslyvaporized(SeeFig.2)clearingthefault,resultinginonlyaminordegradationinperformance.Theself-healingdesignsignificantlylengthensthelifeofABBcapacitors.A/W7/998/2/00,10:01PM34LowVoltageProductsCapacitorConstructionPrincipalComponentsofa3-PhaseCapacitorTheprincipalcomponentsofa3-phaseABBcapacitorinclude:1.SequentialProtectionSystem:•Self-HealingCapacitorElementsOneormoreself-healingcapacitorelementsareinstalledforeachphase.TheseelementsareconnectedinYordelta.Incaseofdielectricbreakdown,thefaultisclearedbyevaporationofthemetallizedlayeraroundthebreakdownwithnegligiblelossofcapacitanceandcontinuedoperationofthecapacitor!•InternallyProtectedElementsAuniqueSequentialProtectionSystemincludingtheIPEdesign(IPE-internallyprotectedelements)ensuresthateachindividualelementcanbedisconnectedfromthecircuitattheendoftheelement’slife.•NonflammableDryVermiculiteFillerVermiculiteisadry,granularinsulatingmaterialthatissolid,inertandfireproof.Thismaterialfillsallopenspacesintheenclosuretoisolatethecapacitorelementsandexcludefreeoxygen.2.DischargeResistorsDischargeresistors(oneforeachphase)aresizedtoensuresafedischargeofthecapacitortolessthan50voltsinoneminuteorlessasrequired.3.TerminalStudsLargeterminalstudsarelocatedinsidetheenclosureatthetopofthecapacitorforquickandeasycableconnections.4.EnclosureAllABBenclosuresaremadeofweldedheavygaugesteel.AvailableenclosuretypesincludeIndoor,OutdoorRaintight,andIndoorDusttight.DesignFeatures1)Robustterminals,easyconnection2)Dischargeresistors3)Self-healing4)Drydielectric5)Thermalequalizer6)Inertandnon-toxicgranules7)Knockout8)Earthterminal9)Heavy-dutyenclosure(Alsoavailableforoutdoorinstallation)10)Verylowlosses11)Easytoinstall1234567891011A/W7/998/2/00,10:01PM45LowVoltageProductsWhatisaMetallized-FilmElements?Metallized-filmisamicroscopicallythinlayerofconductingmaterial(calledanelectrode),usuallyaluminumorzinconanunderlyinglayerofinsulatingfilm.Theelectrodethicknessaveragesonly0.01micronswhileinsulating(polypropylene)filmrangesfrom5to10micronsinthicknessdependinguponthedesignvoltageofthecapacitor(thehigherthevoltagerating,thethickertheinsulatingfilm).AdvantagesofMetallized-FilmElementsTherearetwoelectrodelayersseparatedbyonelayerofinsulatingfilm.Thousandsoftheselayersaretightlywoundaroundacoreinsuchamannerthattheedgeofoneelectrodeisexposedononesideoftheelementandtheedgeoftheotherelectrodeisexposedontheothersideoftheelement(SeeFig.4&5).Wiresarethenconnectedtoeachsideoftheelement.Theelementisenclosedinacontainerandthenfilledwithahardeningprotectivesealant.1.Self-HealingDesignSelf-healingreferstoaprocesswhereashortcircuitbetweenelectrodesvaporizestheelectrodearoundthefault(SeeFig.6)untilthefaultiseliminated.Theelementcontinuestofunctionwithnegligiblelossofperformance(SeeFig.7).2.LowInternalLossesDuetothehighdielectricefficiencyofthemetallized-film,theinternallossesareextremelylow.ABBmetallized-filmdesignlossesarelimitedto0.5wattsperkvarincludingthelossesacrossthedischargeresistors.3.SmallElementSizeDuetothethinelectrodeanddielectric,metallized-filmelementsaresmallandcompactinsizeresultinginsmaller,morepowerfulcapacitors.Thecapacitanceofanyelementdesignisinverselyproportionaltotheseparationbetweenelectrodes.Inotherwords,iftheseparationbetweenconductingsurfacesiscutinhalf,theeffect