HV-EHV Cables Synthetic Isolation

7/27/2019 HV-EHV Cables Synthetic Isolation

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High and extra high voltage cableswith synthetic insulation


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Gl ob a l e x p e r t i n c a b l e s a n d c a b l i n g s y s t e m s


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S u m m a r y

TheevolutionofHVandEHVcableswithsyntheticinsulation 5

Anoutlinehistoryofdevelopments 6

ProjectengineeringforHVcablelinks 7

ExamplesoftherangeofHVandEHV

cableswithsyntheticinsulation 8

Productiontools 9

420 kVcabletechnology 10

Checksandtests 11

References 12

Accessories 13

Services 15

Introduction 4

H i g h a n d e x t r a h i g h vo l t a g e c a b l e s


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Nexans Switzerland

supplieshighandvery

highvoltagepowercables

andaccessories,optical

fibercables,opticalwave-

guideandspecialcables

fortheinternationalmarket.

Nexans Switzerlandhas

threeproductioncentres:

theBreitenbachsite

theCortaillodsite

theCossonaysite.

4

I n t ro d u c t i o n

Nexans Switzerland is

Switzerlandsforemost

cablemakerandsupplier.

Itmanufactures,distributes,

fitsandinstallsacompre-hensiverangeofproducts

forunderground,submarine

andaerialinstallations:

high,mediumandlow

voltagepowercables

copperoropticalfiber

telecommunications

cables

specialcablesfor

manyapplications

powerandtelecom

accessories

connectionequipment.

Itsservicesrangefrom

thesupplyofcablestothe

implementationofcomplex

turnkeyproducts,including

development,engineering,

constructionwork,systemtechnology,laying,installa-

tionandprojectfinancing.

Pos i t i on of N e x a n s S w i t z e r l a n d


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T h e ev o lu t i o n o f H V a n d E H V c a b les

with synthet ic insulat ion

T h e Ca b l e s

aluminiumsheath

compositesheath

Thegreaterdemand

forenergyrequiresthe

implementationofinstallations

designedtosupportincreas-

inglyhighervoltageand

powerlevels.

ThisiswhyNexans

SwitzerlandLtdhasdevel-

opedcableswithsynthetic

(ordry)insulationforvoltages

upto420kVandcross-

sectionsthatcanbelarger

than2000mm2.

Con d u c t or s

Athighgradients,synthetic

insulationissensitivetothe

presenceofmoisture.Itis

thereforeessentialtoavoid

anycontactwithwateror

steamduringfabrication

processesandalsoduringlineoperation.

Thecross-linkingoperation

mustbecarriedoutinthe

absenceofhumidity,either

onacatenarylineinaninert

atmosphere,oronahorizon-

talline(MDCVprocess).

Forallcables,theexternal

protectionisprovidedbya

polyethylenesheath.Over

thisinsulation,theapplica-tionofawaterproofmetallic

sheath,whichalsoactsasa

screen,isgenerallyrequired.

I n s u l a t i on

Higherservicegradientsrequirebetterinsulation

qualities.

Thesematerialsshould

beperfectlycleanthis

isparticularlyimportant,

astheirlong-termperfor-

mancecanbeconsiderably

affected,evenbymicro-

impurities.Precautionsto

ensurecleanlinessshould

betakenbothduringtheproductionofrawmaterials

andthroughouttheentire

cablefabricationprocess.

S h e a t h s

Forconductorcross-sections

largerthan1000mm2,seg-

mentedconductorsmustbe

producedtoreduceconsider-ablytheirresistancetoalter-

natingcurrentbyreducing

theskineffect.

Thissheathcanbemadeof

unweldedextrudedaluminum

orlead,orofweldedor

gluedcopperoraluminum.

NexansSwitzerlandLtduses

allthesetechniqueswith

completemastery.


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An out l ine history of developments

De ve l op m e n t s f r om 1 9 7 3 t o t h e p r e s e n t d a y

Sincetheintroductionof

cross-linkablesynthetic

insulation,productionand

controltechniqueshavegone

throughawholeseriesof

developmentsteps.

1973

1974

1976

1977

1978

1983

1986

1987

19891991

1996

1998

2006

Implementation ofa cross-linkingcatenary line

Delivery of the firstHV cables with dryinsulation

Introduction of the triple-head extrusion process

Delivery of the first150 kV extruded

insulation cable

Modification of thecatenary line fornitrogen cross-linking

Delivery of the first220 kV cable withXLPE insulation

Construction andstart-up of a laboratoryfor measuring partialdischarges up to 480 kV

Production of the firstXLPE Cable 220kVwith a cross-section of2500 mm2

Production of the first275 kV cable withXLPE insulation

Implementation of a2nd cross-linking linefor large conductorcross-sections and thicklayers of insulation

Production of the first400 kV cable withXLPE insulation

Delivery of the first400 kV cable withXLPE insulationabroad

Delivery of the first400 kV cable with XLPEinsulation in Switzerland


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Project engineering for HV cable l inks

De ve l op m e n t

plan

territorialplanning

increaseddemand

connectionofheavyusers

networkplan

networkcalculation

powerflowdetermination

customer

Cause and nature of operations Effects Intervening parties

Pr e - s t u d y

plan decisiontoreinforcenetwork

preliminaryfeasibilitystudy

pilotstudy

choiceofconnectiontype :underground,overheadormixed

technicalsolutions

customer

Nexans

S t u d y

Impactstudy

collaborationwithotherdepartments :engineeringoffices,industrialdepartments,etc.

noticetomunicipalauthoritiesandlandowners

choiceofconnectiontype :underground,overheadormixed

drawingupofspecifications

customer

Nexans

Pr oje c t

choiceofdefinitiverun

definitionoflayingparameters

measurementoflinelength

preparationofcontractorsfile

customer

Nexans

O f f e r s

definitionofpossiblecabletypesorvariants

calculationofthecross-sectionaccordingtovoltage,powerandcivilengineeringparameters

distributionofpartiallengths

groundingsystem

preparationofrequestsforoffersandcontracttendersformaterialsandcontractors

costofcivilengineeringwork

costofinstallationandset-up,scheduleanddetails

customer

Nexans

Authorizations

filefortheauthoritiesconcerned

handlingofpossibleobjections

buildingauthorization customer inspectors

Nexans


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E x a m p les o f t h e ra n g e o f H V a n d E H V

c a b les w i t h sy n t h et i c i n su la t i o n

45kV

EPR insulation

60kV

XLPE insulation

150 kV

XLPE insulation

500 mm2

220 kV

XLPE insulation

2000 mm2

400 kV

XLPE insulation

800 mm2


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HVExtrusionline

Product ion tools

HVlaboratory

Aluminiumpress


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10

extrudedcross-linkedpoly-

ethylene(XLPE)insulation

cableswhich,withthe

progressofthetechniques

usedinthemanufacturing

ofbasicmaterialsand

aboveallforinstallation,

haveachievedtherelia-

bilitylevelrequiredfor

useinextrahighvoltage

(EHV)networks.

4 2 0 kV c a b le t ec hn o lo g y

For420kVcables,there

arecurrentlytwoalternatives

totraditionalfluidoilimpreg-

natedpaperinsulation :

cableswithPPLPinsulation,consistingofthree-layer

laminatedpaperand

polypropylenetapes,

formedintoribbonsand

impregnatedwithoil.

E H V c a b l e s w i t h PPL P a n d X L PE i n s u l a t i on

PPLPinsulation,whichwas

introducedattheendofthe

0s,isstilllimitedtocables

tobeusedatavoltageof

400 kVorhigher.Thisisdue

ontheonehandtoitsprice,

whichishigherthantheprice

ofpaper,andontheother

totheincreasinglygeneral-

izeduseofXLPEinsulationfor

voltagesupto220kVand400 kV.

XLPE Insulation

Cross-linkedpolyethylene

(XLPE)wasintroducedinthe

0s.Itwasinitiallyusedfor

mediumvoltagecables,but

isnowusedasinsulationfor

extrahighvoltagecables

(EHV).Itsuseatvoltage

levelsof400 kVandhigherrequires,ofcourse,sophisticat-

edstate-of-the-arttechnology.In

particular,weshouldmention :

PPLP Insulation

Forextrahighvoltage

(400 kVandhigher),new

typesoftapesmadeofPPLP

(PolyPropyleneLaminated

Paper)areused.Theyhave

theadvantageofcombin-

ingthetraditionalapplica-

tiontechnologyusedfor

impregnatedpapercables

withtheexcellentelectrical

anddielectricpropertiesof

syntheticinsulators.PPLPisa

three-layerinsulationconsist-

ingofapolypropylene(PP)

sheetlaminatedbetween

twosheetsofpaper.PP

improvesthequalityofthe

insulation,whilethesheetsof

paperensurethecirculation

ofoilbetweenthelayers.

Comparedwithpaperinsula-tion,PPLPhasahigherbreak-

downstrengthandaboveall

lowerdielectriclosses.

PPL P a n d X L PE i n s u l a t i on

therigorousselectionof

insulatingandsemi-con-

ductingmaterials,which

mustbeofaveryhigh

puritylevel,

thecheckingoffiltering

duringapplication,

three-layerextrusion(inter-

nalsemi-conductor,insula-

tionandexternalsemi-con-ductor)usingasingletool,

theobtentionofperfectly

smoothinsulationsemi-con-

ductorinterfaces,

protectionoftheinsulation

againstthepenetrationof

moisture,

stringentelectricalteststo

detectanyfaults.

Forconnectionprojectsat

420 kV,exhaustivetestshave

beensuccessfullycarried

outforbothXLPEandPPLP

cables.Themainfeaturesof

thesetwotypesofcablesare

comparedbelow.


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11

Forallthesetasks,reli-

ableandfastmeasurement

equipmentisrequired.

Considerableinvestments

havebeenmadetoequipourmaterialstestlaborato-

rieswiththemostmodern

equipment,suchasthermal

analysisinstruments,tensile

strengthapparatus,optical

Checks and tests

Thematerialsusedinthecon-

structionofEHVcablesare

subjectedtoverystringent

qualitycontrolchecks,both

beforeandafterproduction.Plastics,metalsandtapesall

undergoelectricalresistance

testsandmeasurementsof

theirdielectricormechanical

properties.

F r om c h e c k s on m a t e r i a l s . . .

After-laying tests

tocheckthequalityof

assemblyofaccessoriesafter

installationandtosimulate

cableoperationandrapidly

provideinformationoncable

efficiencyafterprolonged

periodsofuse.

Accelerated ageing teststosimulateworkinglifeand

toprovideinformationwithin

ashorttimeframeontheir

behaviorinlong-termuse.

Diagnostic tests

tohighlightanydegradation

phenomenainthelineinser-

viceandtoprovideinforma-

tionontheresidualcablelife.

Thequalityofhighvoltage

cablelinksishighlydepen-

dentontherigorousnature

ofthetestscarriedoutonthe

cablesandtheiraccessories.

Themorestringentthesetests

are,theloweristheriskof

failureduringoperation.

Theprincipaltestsareas

follows :

Routine tests

toevaluateproduction

quality.

Type tests

tovalidateatypeof

construction,foreither

cablesoraccessories.

Special tests

undertakeninthecase

ofmajordesignchanges.

. . . t o e l e c t r i c a l t e s t s

microscopes,infra-redspec-

trometer,chromatograph,

amongothers.

Theseexactingchecksenable

ustoreducetoaminimumthepresenceofundesirable

matterandtoguaranteethe

qualityofourcables.


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12

R ef eren c es

Pr e s t i g i ou s p r o je c t s

1990 Thefirst420kVcablewasinstalledinSwitzerlandwithXLPEinsulationconnectedtothenetworkatthe"Bassecourt"substationofthe

BerneseElectricityCompany.ThissubstationwasconnectedtoLaufenburgandFranceby0kVoverheadlines.Thecopperconductorcross-sectionwas1200mm2.

1996 Variousinstallationsofdesalinationplantsweresetupalongthecoastofcer-tainArabcountries.Themostimportantoneamongstthemissuppliedwithcablesandacces-

soriesfromNexansSwitzer-landLtd,formerlyCortaillodCossonayCable.Wesuppliedsectionsof400kVcable,withXLPEinsulationandacor-rugatedaluminiumsheath.

1997 NexansSwitzerlandLtd,wasawardedanimpor-tantcontractbyPowerGrid,awhollyownedsubsidiaryofSingaporePower,tosupplyandinstall20 kVXLPEpowercables,2'000mm2withacor-rugatedaluminiumsheathandaccessories.Thiscontractwasthefirstofitskindtobeaward-edbyPowerGridinSingapore.Theprojectconsistedoftwocablerouteswithatotalcablelengthofabout km.

1998 CleusonDixenceproject,Switzerland.

Withawaterfallof1m,

Peltonturbineof42MW,alternatorof.MVA/pole,thisPowerStationsetsworldrecords.

just.monthsbetweentheorderdateandcommissioning.

2000 NexansSwitzerlandlaidtwosublakelinksforSocietElettricaSopracenerina

inLagoMaggiore.Foreachlinkwithalengthof2200m,threecablesoftheXDAluWETtype,1x00mm2,0kVwereruninPEtubespreviouslyinstalledonthelakebed.

2000 Nexanscompleteda20kV(,00mofXAluWT,1x4000mm2)cableinstallationanda12kVinstallation(24 kmofXDFcuCuT,

1x0mm2

)fortwocustom-ersinSpain.

2004 WhentheextensionoftheChicoasenpowerstationnearTuxtlainMexicowasdecidedtoaddafurthergenerators(eachof10MW)tothegeneratorsalreadyinserviceandbringthetotalcapacityto240MW(practicallyonethirdofthetotalproductioninSwitzerland),

Nexansdeveloped,manufac-tured,installedandtestedthex400 kVcablelinks-400kVtypePoAluWET1x400mm2Cu-fromthetransformertothestartingpointoftheoverheadlines.Withthisproject,Nexansonceagainconfirmsitshighlevelsofexpertiseinprojectandinstallationengineering.

2004 WhenTranselectrica(thenationalRomanianelectric-

itytransmissioncompany)issuedaninternationalinvitationfortherestorationofa220 kVcircuitanda400kVcircuit

connectedtothesametrans-formerandbuildingupacrucialpartoftheoperatingsystemofthe"PortiledeFier"(doorsofsteel)powerstation,

Nexanswonthecontract.Incollaborationwithalocalcompanyandwithinanambi-tiouscompletiondate,Nexansremovedtheexistingoil-filledcablesandreplacedthemwithsyntheticallyinsulatedcableswithahigherpowerrating400 kVtypeXDCuTAluWET,1x0mm2Cuand220 kVtypeXKDAlT-Tsc,1x1000mm2Cu.

2006 NexansSuissebegantoexpandintoChinain1,inpartnershipwithanintegrator,withintheframeworkoftheDaYuanDuhydro-elec-tricpowerstationprojectinHunanprovince,forwhichasystemof110kVXLPEcableswassuppliedandinstalled.Furtherprojectsfollowed,inwhichNexansSuissehadthesameresponsibilitiesforthe

supplyofcompletecablingsystemsandfortheon-sitesupervisionoftheinstallations:thefirst220kVXLPEcablesfortheZhengJiangpowerstationweresuppliedinearly200;andsince200,almost0 kmofcables,inparticular220kVcableswithacoppercrosssectionof200mm2,forthesupplyofsub-stationsinPekinginanticipationofthe200OlympicGames.Over

aperiodof10years,nofewerthan21circuitsintotalhavebeeninstalledthroughoutthecountry.

NexansSwitzerlandLtd,manufacturedandinstalledx400m,400 kVXLPEcables,00mm2withacor-rugatedaluminiumsheathand

accessoriesforconnectingthethreetransformerslocatedintherock-cavetotheswitchingsta-tion,acrosstheRhoneriver.

1999 ThroughNexansFrance,NexansSwitzerlandhaswonacontractforthesup-plyof0 kmofXKDAlTcable,1x2000mm2,11kVforTaiwanPower,inTaiwan.

2000 Nexanssupplied

andinstalledXAluWTcablecircuits,1x400mm2and1x0mm2,20kVand120kVcablecircuitsonanindustrialsiteinDearbornintheUnitedStates.

2000 Followingamechani-calaccident,thegaspressurecablesofthe10kVForetailleChnesublakelinkingsec-tionoperatedbyServicesIndustrielsdeGenve,were

damagedinNovember1.NexansSwitzerlandreplacedthesublakelinkwithalengthof200mbycablesoftheXDAluTtypeinarecordtimeofmonthsbetweentheorderandcommissioning.

2000 Followingafireintheaccesstunneltothe"ElCajon"powerplantinHonduras,twooil-filled220kVcablesweredamaged.Nexans

replaced2circuitswithalengthofaround1000mbyXAluWTcables1x00mm2,220 kV.Thisprojectwascompletedin


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1

A c c esso r i es

O u t d oor s e a l i n g e n d s w i t h p or c e l a i n i n s u l a t or

Theconceptofthesealing

endwithporcelaininsulator

hasalong-termexperience

withpaperinsulatedcables

ofmorethan0years.The

sealingendincludesapre-moldedslip-onstresscone.

Com p os i t e i n s u l a t or s f or va r i ou s a p p l i c a t i on s

Thousandsofcompos-

iteinsulatorshavebeen

installedsince10byour

companies,someofthem

areinserviceundervery

severeconditions,atthefull

satisfactionoftheirusers.

Asanalternative,customers

worldwideaskmoreand

moreforsyntheticinsulators.

Suchinsulatorsarecomposed

ofafibreglassreinforced

epoxytubewithtwoalumi-

niumflangesandinsulated

bysiliconesheds.

Specialadvantagesare

lowweight,excellentseismic,

mechanicalandpollutionperformancesaswellas

noexplosionrisk.

Dr y t y p e ou t d oor s e a l i n g e n d s

to14kV,offersmany

additionaladvantageslike:

noriskofleakage;

noenvironmentaleffect

easyhandling

quickinstallation

Since20years,Nexans

offersslip-ondrytype

outdoorsealingends,

whichdontneedanyoilorgasfilling.

Amonoblocversion

availableforvoltagesup

O u t d o o r s e a l i n g e n d s w i t h c o m p o s i t e i n s u l a t o r


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GI S s e a l i n g e n d s / T r a n s f or m e r s e a l i n g e n d s

TheGISsealingendsaredesignedinaccordance

withIEC0standard,

eitheraccordingtoitem.1

forfluidfilledterminationsor

item.2,TypeAfordrytype

terminations.

FortheconnectionofHVcablestotransformer

orgasinsulatedswitch-

gears,Nexansmanu-

facturingprogramme

includesadequate

terminations.

Jo i n t s

coppertubeandarobustPEcovering.Shieldbrake

facilitiesareintegrated,

factorymadeandfactory

tested.

MOP :MediumOuter

Protectionconsistingofa

synthetic,rigidcover.

LOP :LightOuterProtection

madeofheatshrink

components.

Nexansprefabricatedhighvoltagejoints(2-0 kV)

arebasicallycomposedof

apremoldedelastomerjoint

body,andanoutercasing.

Forthe2 kVLevel,a

cablejointwithpremolded,

factoryexpandedjointbody

isavailable.

Outerprotectionsforjoints

areavailableindifferentversions :

HOP :HeavyOuterProtection

casingconsistingofastrong

Tr a n s i t i on jo i n t s

Nexanshasdevelopeda

conceptwhichguaranteesa

highreliableandcompactconnectionforHVcablesof

differenttechnologies.

Whenpaperinsulated

HVcableshavetobe

connectedtosyntheticinsulatedcables,aso

calledtransitionjointis

needed.

V a r i ou s a c c e s s or i e s a n d t ool s

acableinstallation,such

ascablescreendiscon-

nectingsystems,surgearrestors,cableclamps,

etc.

Wherespecialequipments

arerequiredfortheproper

installationofHVPowerAccessories,Nexansoffers

suchtools,aswellasthevar-

iousaccessoriestocomplete


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1

N ex a n s S w i t z er la n d

Nexans Switzerland

providesawiderange

ofservicestoitscustomers,

extendingfromengineering

tocablelayingandinstallation.

Workingtotheinstructions

ofexperiencedteamsof

engineers,highlyqualified

fittersinstallcablesystems

allovertheworld.Laying

andinstallationmaterials

whichareoptimizedinevery

respect,togetherwithmea-

suringandtestinginstrumentsforeveryneed,permitthe

implementationofallkinds

ofinstallationsunderthebest

possibletechnicalandcom-

mercialconditions.

Cablesdeliveredand

installedbyNexans

Switzerlandguarantee

areliableservicefor

manyyears.

Basedonitsextensiveexperi-

encewithlowandmedium

voltagecables,Nexans

Switzerlandoffersitsclients

anexpertpartnershipto

solveproblemsandimple-

mentpracticalsolutions.

A n e x p e r t a n d c om p r e h e n s i ve s e r v i c e


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Nexans Switzerland Ltd2, rue de la Fabrique CH 2016 Cortaillod

Phone. 41(0) 32 843 55 55 Fax 41(0) 32 843 54 43

http://www.nexans.ch

G l o b a l e x p e r t i n c a b l e s a n d c a b l i n g s y s t e m s

2006

HV-EHV Cables Synthetic Isolation

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