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Hubnet Colloquium Strathclyde University – Glasgow, Scotland (UK) December 7 th 2016 Extruded Cable Systems for HVDC Transmission Prof. Giovanni Mazzan* Dept. Electrical, Electronic & Informa5on Engineering “Guglielmo Marconi” Alma Mater Studiorum - University of Bologna, Italy 1 Hubnet Colloquium - Strathclyde University, Glasgow, Scotland (UK) - December 7th 2016

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Page 1: Extruded Cable Systems for HVDC Transmission - · PDF fileExtruded Cable Systems for HVDC Transmission ... Ø OF-PPLP = impregnated with non-viscous oil ⇒ ... uniform compact layer

HubnetColloquiumStrathclydeUniversity–Glasgow,Scotland(UK)

December7th2016

ExtrudedCableSystemsfor

HVDCTransmissionProf.GiovanniMazzan*

Dept.Electrical,Electronic&Informa5onEngineering“GuglielmoMarconi”AlmaMaterStudiorum-UniversityofBologna,Italy

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

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Introducingmyself…

1)  MD(1986)andPhDinElectrotechnicalEngineering(1992)atUNIBO

2)  Since1992withDEl-UNIBO.Since2004AssociateProfessorofPowerQualityandHVEngineering.Researchfields:insulaVonaging(lifemodels,SC),RES,EMF

3)  Since2009ConsultantofTERNA(ItalianTSO).HVDCprojects:SAPEI,SACOI, ITA-FRA(Piemont-Savoie),ITA-MON

4)  CoauthorofG.MazzanV,M.Marzino]o,ExtrudedCablesforHighVoltageDirectCurrentTransmission:AdvancesinResearchandDevelopment,PowerEngineeringSeries-Wiley-IEEEPress,2013

5)  Since 2012 Chairman of IEEE DEIS TC “HVDC cable systems (cables, joints &terminaQons)”.Since2015ChairmanofIEEEDEISWG“HVDCcablesystems”fordeveloping IEEE Standard P1732: “Recommended prac5ce for space chargemeasurementsinHVDCextrudedcablesforratedvoltagesupto550kV” 2

HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

SUMMARY

1)  FundamentalsofHVDCextrudedcabletransmission[chp.1-2I-B]

2)  Designparameters:HVDCvsHVACcabledesign[chp.3I-B]

3)  MainrealizaVonsworldwide[chp.7I-B]

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

1)  FundamentalsofHVDCextrudedcabletransmission[chp.1-2I-B]

2)  Designparameters:HVDCvsHVACcabledesign[chp.3I-B]

3)  MainrealizaVonsworldwide[chp.7I-B]

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Historyofpowertransmission:fromDCtoACØ  PowerT&DstartedwithDC:

-1879: (T.A.Edison) incandescent lamp+useofdynamo⇒1882,PearlStreetStaVon,NYC(6x100-kW“jumbodynamos”+30kmu.g.cables)

-1882:50-km2-kVDClineMiesbach-MunichinGermany

Ø  From DC to AC (Tesla & WesQnghouse) ⇒ transformers andinducVonmotors⇒ACdominantingeneraQon,T&D,uQlizaQon

Ø  ACsystemvoltageconversionissimple:• transformer (high power and insulaVon, low losses, li]le

maintenance)• 3-φsynchronousgeneratorsuperiortoDCgenerator 5

HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

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DisadvantagesofHVACpowertransmissionØ  ACpowertransmissionhasalsodisadvantages,e.g.

1)  NoconnecQonbetweenACsystemswithdifferentfrequencies

2)  Weak connecQon between independent AC systems ⇒ systeminstability(DOMINOEFFECT)orundesirablepowerflow

3)  InducVve & capaciVve elements of OHLs and cables⇒ limits totransmission capacity and distance. Strong limitaVon for HVACcables:inthe40-100kmrange(~70kmat220kV,~40kmat400kV)increasingto50-150kmwithopVmizedreacVvecompensaVon

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Fig.2.1–Cabletypologiesusedvs.length,powerandvoltage(aQer[7.2.I-B])7

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AdvantagesoftransmissionwithHVDCcables(1)1)  lowerlosseswithsamecurrent(conductor≡noskin&proximityeff.,

metallicsheath&armoring≡nolosses,dielectric≅nolosses)2)  higheraverageelectricfield⇒highercableuQlizaQon

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AdvantagesoftransmissionwithHVDCcables(2)

3)  conductor and insulaVon savings ⇒ HVDC cables cheaper thanHVACcablesforsamepowerraVng⇒lowerp.u.l.linecosts

4)  cable lengths not limited by reacVve power (no reacVvecompensaVonatendstaVonsand/orintermediatepoints)

5)  DC transmission ≡ asynchronous link with ≈ no increase in faultlevel

6)  powerfloweasilyandquicklycontrollable⇒DC linkcan improveACsystemstability

7)  uniqueusageofHVDCcables:subseapowerlinksonlongdistances9

HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

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Ø  HVDCtransmissiondisadvantages:AC/DCconvertercosts&losses⇒breakevendistance(BD)≡savingsinlinecostsoffsetconvertercosts

Ø  Total (line + losses) cost ⇒ DC-lesssteepthanAC-curvesdueto•  lower p.u.l. line investment

cost (OHL: narrow ROW &sm a l l t owe r s , 2 v s . 3conductors ; cab les : lowconductor&insulaVoncost,noreacVvecompensaVon)

•  lower capitalized losses cost(noAClosses)

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

ACvs.DCtransmission:economiccomparison

Fig. 2.8 - HVAC vs. HVDC transmission system costs (after [4.2.I-B])

Ø  At500kV:BD≈500kmforOHLs,≈40kmforcables(seeabove)

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•  highpowerandvoltageraVngs•  lowlosses•  highreliability•  acceptablecosts•  goodperformances

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

AC/DCconvertersØ  DCtransmissionrequiresAC/DCconverterswith(ideally):

Ø  TwoconvertersmainlyusedforDCtransmission:

•  Line-CommutatedCurrent-SourceConverters(LCC)

•  Self-CommutatedVoltage-SourceConverters(VSC)

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

AC/DCconverters:LCC(1)Ø  Firstdeveloped:LCC(=tradiVonalDCtransmission,HVDCClassicTM)

Fig. 2.11 - LCC with SCR valves arrangement (after [5.2.I-B])

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Ø  LCCdevelopment:

1)  MercuryarcrecQfiersinthe1930’s⇒LCCdesignpossible

2)  Silicon Controlled RecQfiers (SCR, or thyristors) in the late1970’s:oil-immersed,parallel/seriesconnecVon

3)  State of the art: air-insulated water-cooled Light-TriggeredThyristors(LTT):highercurrent&voltage,lesscomponentspervalve⇒higherreliability⇒highestpower&voltageraQngs

Ø  Power flow reversal: by reversing voltage polarity⇒ criQcal forHVDCextrudedcableinsulaQon!

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

AC/DCconverters:LCC(2)

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

AC/DCconverters:VSC(1)Ø Morerecent(late1990s)thanLCC,VSC(HVDCLightTM,HVDCPlusTM)

Fig. 2.12 - VSC with IGBT valves arrangement (after [5.2.I-B])

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

AC/DCconverters:VSC(2)

Fig. 2.7 – Operating range for HVDC VSC (after [5.2.I-B])

Ø MaincharacterisVcsofVSC:

•  semiconductors with turn-offcapability:IGBT

•  four-quadrantoperaQon•  highlosses•  powerupto≈1000MW

Ø  Power flow reversal: byreversing current flow⇒ novoltagepolarityreversal⇒okfor HVDC extruded cableinsulaQon!

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1)  DisadvantagesofLCC:1)  reacQvepowerdemandfromACnodes2)  injecVonofcurrentandvoltageharmonics⇒capacitorbanksonACside&harmonicfiltersonACandDCside

2)  DisadvantagesofVSC:lessexperience,lowervoltage/powerraVngs

AC/DCconverters:LCCvsVSC

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

Fig. 2.6 – HVDC with VSC (after [5.2.I-B]) Fig. 2.5 – HVDC with LCC (after [5.2.I-B])

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

DevelopmentofLCCandVSCØ  Since VSC-HVDC started (1990s), the increase of voltage &

powerforIGBT-VSChasparalleledthatofSCR-LCCin1970s

Fig. 2.13 – Solid-state converter development (after [5.2.I-B])

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(From [LW2013]:MarcoMarelli, “Achievement and experience in service of long lengthHVDC electricallinks by insulated power cables”, LaVnAmericanWorkshop 2013, Foz do Iguaçu – September 6th, 2013.CourtesyofPrysmian)

ACvsDCCableTransmissionSystems

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1)ground/seaelectrodes2) “metallic return”:MVcable grounded at 1converterstaVon3) midpoint grounded12-pulse conv. + 2 1/2-voltagepoles(nogroundcurrent)

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

HVDCcablelineconfiguraQons:(1)monopolar

Fig.2.11-HVDCconfiguraVonsandoperaVngmodes(axer[5.2.I-B])

Ø Monopolarsystems:simplestandcheapestformoderatepower:2convertersand1HVpoleonly.

Ø  AlternaVvesforreturncurrent:

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Ø OperaQngmodes:1)  Normal (balanced)

⇒ 0 g r o u n dcurrent

2) Monopolar groundreturn:1poleoutage3) Opposite pole formetallicreturn:outageof1converter(ateachend pole/converterbypassswitch) 20

HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

HVDCcablelineconfiguraQons:(2)bipolarØ  Bipolarsystems:mostcommon,one12-pulseconverterperpole

andterminal⇒2independentcircuits(1/2capacityeach)Fig.2.11-HVDCconfiguraVonsandoperaVngmodes(axer[5.2.I-B])

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Ø  ClassificaQonbasedontheinsulaQontype:

q Oil-paperinsulated-  Mass-ImpregnatedNon-Draining(MIND)-  oilfilled(OF)

o  LowpressureOF(LPOF,SCOF,SCFF)o  HighpressureOF(HPOF)

q Polypropylene-LaminatePaper(PPLP)orPolypropylenePaperLaminate(PPL)

q Gasfilledcables

q Extruded(XLPE,thermoplasQc)21

HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

HVDCcabletypes

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Ø Usedinmanylinks,highestvoltages&longestlengths: up to 500-600 kV, 1000 MW in 1cable, depths under sea up to 1640 m,≈unlimitedlengths.Structure:1)  compactstranded/segmentedCu/Alconductor2)  carbon-loadedpaperconductorsemicon3)  InsulaVon(Kraxpapertapesimpregnated

withhigh-viscositymineraloils)4)  carbon-loadedpaperinsulaVonsemicon5)  metallic(leadalloy)sheath6)  thermoplasVcjacket7)  steeltapereinforcement(subseacables)8)  bedding(subseacables)9)  armorofsteelround/flatwires(subseacables)

Ø  Conductortemperature:max.55°C⇒limittocapacity 22

HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

HVDCcabletypes:MIND(1)

Fig.2.16(a)-MINDHVDCdeepwatercableforSAPEIsubsealink(aQer[I-B],courtesyofPrysmian)

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

HVDCcabletypes:Oil-Filled(OF)Ø  InsulaVon: paper + low-viscosity oil. Conductor

with longitudinal duct for oil flow along thecable.Otherlayersare≈sameasabove

Ø Oil-filledcablesokforACandDCvoltages:DCvoltagesupto600kV,greatseadepths

Ø Oil flow along cable⇒ lengths limited to<100km,riskofoilleakageintheenvironment

Ø Oil-filledcablesdividedinto:i)single-coreoilfilled(SCOF)=lowpressureoilii)highpressureoilfilled(HPOF)=cableslaidinapipefilledwithhighpressureoil

Fig.2.16(b)SCOFHVDCcable(aQer[I-B],courtesyof

Prysmian)

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

HVDCcabletypes:PPLPØ  Polypropylene Paper Laminate (PPL or PPLP) =

LappedThinFilmInsulaVon

Ø OF-PPLP = impregnated with non-viscous oil ⇒similartoSCOFcables

Ø MI-PPLP=impregnatedwithviscous(non-draining)oil⇒ similar toMINDcables: ok for long&deepsubsealinks

Ø  Claimedtooperatewithconductorat80-90°Candupto60%higherelectricalstressthanMIND

Ø  Technology under development for DC-cables (KiiChannel,Westernlink:England-Scotland)

Fig.2.16(c)–MI-PPLP

HVDCcable(aQer[I-B],courtesyofPrysmian).

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

Fig.3.4–StructureofHVDCXLPE-insulatedcablesforland(leQ)andsea(right)usagewithVSCconverters

(aQer[I-B],courtesyofABB)

Conductor Copper or aluminium

Conductor Aluminium or Copper

Conductor screen Semi-conductive polymer

Conductor screen Semi-conductive polymer

Insulation Dry cured polymer

Insulation Dry cured polymer

Insulation screen Semi-conductive polymer

Insulation screen Semi-conductive polymer

Swelling tape

Swelling tape Lead alloy sheath

Metallic screen Copper wires

Swelling tape Inner jacket Polyethylene

Aluminium laminate Outer covering Polyethylene

Swelling tape

Tensile armour Galvanized steel wires

Outer covering

Polypropylene yarn

HVDCcabletypes:extruded(1)

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

(a) (b)Fig.2.19–TwotypesofHVDCXLPE-insulatedcable:

(a)landcable(aQer[25.2.I-B]);(b)submarinecable(aQer[I-B],courtesyofPrysmian)

HVDCcabletypes:extruded(2)

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Ø  Extrusion:uniformcompact layerofpolymer laidaroundconductorbetween2semiconlayers

Ø  Besttodate:•  tripleextrusionofinsulaQonthickness+inner&outersemicons•  X-linkingof insulaVon (if needed,XLPE): dryenvironment (N2) +

DCP X-linking agent⇒ X-linking by-products that store SC⇒degassing--->thisaxernoon

Ø  TripleExtrusionLine:1)  conductorentersTripleExtrusionCrossHead2)  output:insulatedconductor⇒entersX-linkingpipe,catenaryor

verVcal≡highp&T,longenoughforthermo-chemicalX-linking3)  finishedcablecoreviaconVnuousproducVon 27

HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

HVDCextrudedinsulaQontechnology:extrusion

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Ø  ExtrudedXLPEinsulaVonadvantagesvs.oil-papercables:•  lowercosts•  easier(faster,cheaper)joinQng•  environmentalcompaQbility(nooilleakage)•  conductortemperature>MINDcables:

o  HVACXLPE:conductortemperature=90°C(service),250°C(shortcircuit)o  HVDCXLPEconductortemperature=70°C(Hokkaido-Honshulink90°C)

Ø  ExtrudedXLPEinsulaVondisadvantagesvs.oil-papercables:•  weakpoints(defects)--->thisaxernoon•  suffers space charges (SC) and polarity reversals ---> this

axernoon•  lessserviceexperience&lowervoltages--->thisaxernoon

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

Extrudedvs.oil-paperDCcables:pros&cons

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

1)  FundamentalsofHVDCextrudedcabletransmission[chp.1-2I-B]

2)  Designparameters:HVDCvsHVACcabledesign[chp.3 I-B]

3)  MainrealizaVonsworldwide[chp.7I-B]

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

DesignofACcables:(1)thermaldesign

θc=designconductortemperature[known]θa=ambienttemperature[known]Pd=dielectriclosses[notofmainsignificance,preliminaryevaluaVonfromU0,Eave]γ=addiVonallossesinmetalliclayers(screen,armors)Ti=thermalresistancesofcablelayers(T1,T2,T3)+environment(T4).Mainrole:T4[known]Rca=ACelectricalresistanceofconductoratdesigntemperature∝1/conductorX-secVon⇒conductorX-secQon⇒conductorradiusri

P=3U0Iaccosϕ

(5.3ac)

(5.5ac)

Ø Maindesignparameter=maximumtransmissionacQvepowerP

Ø U0=Un/√3=ratedφ-to-groundvoltageofcablesystem⇒Iac=ampacityofunipolarcable⇒thermaldesignaxerIEC60287,seeeq.(5.3ac):

Ø U0+conductorradiusri⇒electricaldesign⇒insulaQonthicknessfromACelectricfield

)])(1([)()(

321

321

TTTRTTTPI

ca

dacac +γ++

++β−θ−θ=

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

DesignofACcables:(2)electricaldesign

⎟⎟⎠

⎞⎜⎜⎝

⎛=

i

oAC

rr

r

UrE

ln)( 0

(3.1)

EAC(r)=ACelectricfieldatradiusrU0=designvoltage(AC:φ-to-ground)[known]ri=insulaVoninnerradius[known]r=genericradiuswithininsulaVonro=insulaVonouterradiusEMAX=maximumfieldEMIN=minimumfieldØ  fieldprofile•  EMAXalwaysatconductor-insulaQon•  EMINalwaysatinsulaQon-screen

Fig.3.5–ElectricfieldinACcableinsulaVon:“Laplace”,or“capaciVve”,or“ε-dependent”field(axer[I-B])

Ø  ACvoltagewithstandproperQesofinsulaQon⇒EMAX⇒outerinsulaQonradiusro⇒insulaQonthicknessd=ro-ri

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

DesignofACcables:≈completedØ  Known:

•  conductorradiusfromthermaldesign•  insulaQonthicknessfromelectricaldesign

Ø  Thesetwodesigns≈donotinteractwitheachother⇒needed

onlyarefinedevaluaVonofampacityfrom:

•  refinedevaluaVonofdielectriclosses•  “finetuning”ofcablelayers(screen/sheath,jacket,etc.)•  deeperstudyofenvironment(route,soil,etc.)

Ø  Ampacityupdated

Ø  ACcabledesigncompleted

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

DesignofDCcables:(1)samestarQngpoint…

θc=designconductortemperatureθa=ambienttemperatureTi=thermalresistancesofcablelayers(T1,T2,T3)+environment(T4).Mainrole:T4[known]Rdc=DCelectricalresistanceofconductoratdesigntemperature∝1/conductorX-secVon⇒conductorX-secQon⇒conductorradiusri

P=2U0Idc(bipolarsystem)

(5.3)

(5.5)

Ø Maindesignparameter=maximumtransmissionpowerP

Ø  1stchoice(non-trivial≡inv.costs,losses,etc.):ratedpole-to-groundvoltageU0⇒Idc=ampacityofpolecable⇒preliminarythermaldesignaxerIEC60287,seeeq.(5.3):

)()(

4321 TTTTRI

dc

acdc +++

θ−θ=

Ø U0+conductorradiusri⇒electricaldesign⇒inprinciple,insulaQonthicknessfromDCfield.Problem:DCfieldofcablesdiffersbymuchfromACfield!

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

DesignofDCcables(2):…butmanydifferences!Ø Maindifference:Maxwell’sequaVons⇒

1)  DCelectricfieldEDCaffectedbyelectricalconducQvityσofinsulaVon,affectedinturnbytemperatureandfield⇒EDCdependsoninsulaQontemperaturedropΔT(∝conductorlossesWc∝cablecurrent∝load)⇒fieldprofileinversionbetweenmin.andmax.loadpossible⇒designfield/insulaQonthicknessforoneloadcondiVon(e.g.zero)notokforanother(e.g.maximum)

2)  ampacityaffectsEDC⇒selecVonofvoltage,ampacity(losses),field,insulaQonthicknessinherentlyinterlinked

Ø 2nddifference:EDCinsteady-stateisnotthesameasintransients

Ø 3rddifference:Maxwell’sequaQons⇒spacecharge(SC)altersEDC---->thisaxernoon

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

Noloadvsunder-loadcondiVonsinHVDC:1)  cableenergizedatzeroload⇒temperaturedropacrossinsulaVon

ΔT=0⇒EDC“quasi-Laplacian”or“quasi-capaciVve”(≈geometricalvariaVononly,similartoEACinFig.3.5)

2)  cableenergizedunderagivenload⇒equilibriumvalueofΔT≠0:

ElectricfieldofDCcablesinsteady-state(1)

)]()(exp[),( 000 EEbTTaET −+−=σσ (3.10)

])/)((exp[),( 000γσσ EETTaET −=

σ(T,E) = σ0 exp(-Ga/kBT) sinh(cE)/E

(3.11)

(3.12)

⎟⎟⎠

⎞⎜⎜⎝

πλ=−=Δ

i

o

T

Coi r

rWrTrTT ln2

)()(

⇒“Poissonian”EDCdependsonΔTviaσ.

Experimentalexpressionsforσvs.EandTinDC-XLPE:

(3.14)

Mostused

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

Ø Maxwelleqns.inS.S.+(3.10)+simplifyinghypotheses⇒Eoll’sformula:

(3.29)

[inversioncoefficient]

(3.27)

⎥⎥⎦

⎢⎢⎣

⎡⎟⎟⎠

⎞⎜⎜⎝

⎛−

⎟⎟⎠

⎞⎜⎜⎝

=

δ

δ

δ

o

io

o

rrr

rrU

rE

1

)(

1

0

( )

( )

( )

( )io

o

io

o

io

io

o

io

o

dT

c

rrbU

rrbU

rrTa

rrbU

rrbUaW

−+

−+

Δ

=

−+

−+

πλ=δ

1

)/ln(

1

2 ,

Ø  (3.29)vs.(3.1)⇒steadyDCfieldfarmorecomplexthanACfield

Ø  From(3.29),(3.27)steadyDCfielddependsnotonTbutonΔTonly⇒onJoulelossesintheconductorWC

ElectricfieldofDCcablesinsteady-state(2)

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ElectricfieldofDCcables:steadyfieldprofiles

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

Reference“standard”cable:U0=450kV,1600mm2Cuconductor,ri=23.2mm,ro=42.4mm,ρ0=1x1016ΩmatT0=293K,E0~0kV/mm,a=0.11/°C,b=0.03mm/kV.Underload,inversioncoefficientδ>1fortemperaturedropΔT=10,15,20°C⇒fieldinversion!!

Fig.3.9(b)–SteadyDCfieldprofilesunderno-loadfor“standardcable”using(3.29)(aQer[I-B])

Fig.3.16(b)-SteadyDCfieldprofilesunderloadvs.ΔTfor“standardcable”using(3.29).Inversioncoefficientδ>1⇒fieldinversionoccurs(aQer[I-B])

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Combinedelectro-thermallifemodel:loadcyclesØ  [GMDC]:24-hloadcyclestd,givendependenceI(≡load current)=f(t), t∈[0,td] ⇒cumul.damageMiner’slawforDCcableinsulaVonatradiusr:

LFDC(r)=loss-of-life fraction within td KDC(r)=number of “cycles-to-failure”

1)()()()(0

==∫ rLFrKrdLFrK DCDC

t

DCDC

d

( ) ( )[ ] )(/1,,,/)()(00

rKtrTtrELdtrdLFrLF DC

t

DC

t

DCDC

dd

=∫∫ ==

Ø DCcablelifefromKDC,min=minimumnumberof“cycles-to-failure”KDC(r)withininsulaVon:

( ) ( ) ( ) )41.6(),('exp)(/),())(),,(( ),('00

0 trTBrEtrEtTtrE trTbnDCt

ET −= −−αα

]}[),(min{ ,min, oiDCdDCdDC rrrrKtKtL ∈×=×=

0 5 10 15 20 2520

22

24

26

28

30

Time of the daily cycle [h]

Elec

tric

field

[kV/

mm

]

inner insulation surface25% insulation thickness50% insulation thickness75% insulation thicknessouter insulation surface

Inner insul. 25% insul. 50% insul. 75% insul. Outer insul.0

5

10

15

20

25

30

Loss

-of-l

ife fr

actio

n [%

]

ZL period (120 days)HL periods (80 days)LC periods (160 days)

Loss-of-lifefracVonsfor360-kV,2000mm2Al,20mmDC-XLPEcableinLC,HL,ZLperiodsandwhole360daysofPQtestsatsame5locaVons(axer[GMDC])

T

E

HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

1)  FundamentalsofHVDCextrudedcabletransmission[chp.1-2I-B]

2)  Designparameters:HVDCvsHVACcabledesign[chp.3I-B]

3)  MainrealizaQonsworldwide[chp.7I-B]

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

(From[LW2013].CourtesyofPrysmian)

Ø  ExponenQalincreaseofHVDCcablemarket!Ø  Paper-oilcablesruledunQl2000,thenextrudedcablestookoff!

HVDCcablemarket

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

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Table7.1–MainHVDCextrudedcablesystemsinserviceworldwide(aQer[I-B])MainrealizaQonsworldwide(end2012)

Project Customer Country Sea/land Year Length(km) U0(kV) Power(MW) Cond.(mm2)

Hokkaido-Honshu EPDC Japan Sea 2012 44 ±250 600 600

East-WestInterc. EirGrid Ireland-Wales Land 2012 75 ±200 500 -

East-WestInterc. EirGrid Ireland-Wales Sea 2012 186 ±200 500 -

Valhall BP Norway Sea 2011 292 150 78 -

BorWin1 Transpower Germany Sea 2011 243.3 ±150 400 1200

BorWin1 Transpower Germany Sea 2011 22.6 ±150 400 1600

BorWin1 Transpower Germany Land 2011 155.3 ±150 400 2300

TransBay CaliforniaTSO USA Sea 2010 160 ±200 400 1100

TransBay CaliforniaTSO USA Land 2010 10 ±200 400 1100

Estlink NordicEnergyLink Estonia-Finland Sea 2006 150 ±150 350 1000

Estlink NordicEnergyLink Estonia-Finland Land 2006 62 ±150 350 2000

Troll-A Statoil Norway Sea 2004 284 ±80 2x41 300

Cross-Sound Transenergie-US USA Sea 2002 83.2 ±150 330 1300

Murraylink Transenergie-US Australia Land 2002 223.2 ±150 220 1200

Murraylink Transenergie-US Australia Land 2002 136.8 ±150 220 1400

DirectLink Transenergie-US Australia Land 1999 390 ±84 3x60 630

GotLight GotlandEnergy Sweden Land 1998 140 ±80 50 340

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

SummaryofmainrealizaQonsworldwide(end2012)

Totalinstalledlengthofsubmarinecables(km) 1237

Totalinstalledlengthoflandcables(km) 1119

Grandtotalofinstalledlengthofcables(km) 2356

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

TransBayProject(commissioned2010):thesubmarinecable

Fig. 5.11 - Trans Bay cable design (after [I-B], courtesy of Prysmian)

Ø  ±200kV,400MW,∼2x83km,SanFranciscoBay(USA),commissioned2010(firstextruded200kV-DCattheVme).Cablestructure:

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

TransBayProject:thecablesystem

Fig. 7.16 - Cross Section of HVDC Cable for the Trans Bay Cable Project (after [I-B], courtesy of Prysmian)

Ø  ±200kV,400MW,1100mm2Cuconductor,VSCMMC

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

TransBayProject:thecableroute

Fig. 7.13 – The Trans Bay Project route

(after [I-B], courtesy of Prysmian).

Fig. 1.4(a) – Sketch of cable interconnections of the Trans Bay Cable Project (after [I-B], courtesy of Prysmian).

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

Example,TransBayProject:layingacQviQesFig.7.15–Facili*esusedforthelayingac5vi5esoftheTransBayCableinSanFranciscoBay,USA:b)turntableaboardtheshipGiulioVerne(after [I-B], courtesyofPrysmian)d)Hydroplow(after [I-B], courtesyofPrysmian)

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Ø  ±250kV,600MW,commissionedattheendof2012.Mainfeatures:

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

SubmarinecableforHokkaido–HonshuinterQe(commis.2012)

Fig.7.17.±250kV,600MWHokkaido–Honshuinter5e,Japan:(a)route;(b)powercable(aQer[I-B],courtesyofElectricPower

DevelopmentCo.Ltd.&J-PowerSystemsCorpora5on)

•  Max.conductorT=90°C•  okforpolarityreversal

•  DC-XLPEcompound(PolarizedinorganicnanofillersforsuppressingSC,keepingel.resisVvityhighathighT,improveDCbreakdownstrength)

•  SuccessfullypassedqualificaVonaxerCIGRÉ219

•  lightningimpulsewithstand±750kV,withsuperimposedDCvoltage±530kV

(UDC=250kV)∓

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

RecentlyinserviceorongoingHVDCextr.cablesys.projectsTable7.2.a-HVDCLightTMextrudedcablesystems(aQer[22.7.I-B],courtesyofABB)

(from[PryRL],courtesyofPrysmian)

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

GermanNorthSeaOffshoreWindFarmProjects

(From[LW2013].CourtesyofPrysmian)

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

InterconnecQonSpain-France320kVDC«INELFE»

(From[LW2013].CourtesyofPrysmian)

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(From[LW2013].CourtesyofPrysmian) 51

HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

UK:EastWestInterconnector

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

UK:NemoLinkØ  “NemoLink”:

•  1st400-kVratedXLPE-insulatedHVDCcablesystem•  Bipolarlink,1000-MWratedpower

Ø  Cablecontractor:JPS,contractawardedin2015,overallprojectvalue≈500M€

Ø  Cableroute:•  betweenRichboroughEnergyParkinKent(UK)andZeebrugge(Belgium)•  130-kmsubsea•  11.5-kmland

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

UK:WesternLinkØ  HVDCWesternLinkbetweenScotlandandEngland:

•  HVDCbi-polarcablelink•  MI-PPLPcableinsulaVon

Ø  Cablecontractor:Prysmian,contractawardedin2012,overallcablesystemvalue≈800M€(highestattheVme)

Ø  Cableroute:•  400km,mostlysubmarine•  ShortlandsecVoninScotland•  LongerlandsecVoninEngland-Wales

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[I-B]G.MazzanV,M.Marzino]o,ExtrudedCablesforHighVoltageDirectCurrentTransmission:AdvancesinResearchandDevelopment,PowerEngineeringSeries-Wiley-IEEEPress,2013.[4.2.I-B]HighVoltageDirectCurrenttransmission:proventechnologyforpowerexchange,SiemensAG–PowerTransmissionandDistribuVon:HighVoltageDivision,Erlangen,Germany,2003.[5.2.I-B]M.P.Bahrman,B.K.Johnson,“TheABCsofHVDCtransmissiontechnologies”,IEEEPowerandEnergyMagazine,Vol.5,N.2,pp.32-44,March-April2007.[7.2.I-B]A.Orini,M.Marelli,E.Zaccone,“IcollegamenVincavoHVDC:statodell’arteeprospe�vefuture”,AEITWorkshop-HVDCTransmission:Technology,StateoftheArtandPracVcalExperiences,Rome(Italy),November27th2008(inItalian).[10.2.I-B]M.Jeroense,“HVDC,thenextgeneraVonoftransmission.Highlightswithfocusonextrudedcablesystems”,Proc.2008InternaVonalSymposiumonElectricalInsulaVngMaterials(ISEIM2008),pp.10-15,Yokkaichi,Japan,Sept.7th-11th2008.[LW2013]M.Marelli,“AchievementandexperienceinserviceoflonglengthHVDCelectricallinksbyinsulatedpowercables”,LaVnAmericanWorkshop2013,FozdoIguaçu–September6th,2013.[25.2.I-B]R.N.Hampton,“SomeoftheconsideraVonsformaterialsoperaVngunderhigh-voltage,direct-currentstresses”,IEEEElectricalInsula5onMagazine,Vol.24,No.1,pp.5-13,Jan.-Feb.2008.[22.7.I-B]DolWin2–900MWHVDCLighttransmissionTheworld’slargestwindpowergridconnecVon,ABBABGridSystems–HVDC,POW-0075rev.0.[PryRL]Reference_List_HVDC_2016_03_17_rev_01.pdf[GMDC]G.MazzanV,“LifeesVmaVonofHVDCcablesundertheVme-varyingelectro-thermalstressassociatedwithloadcycles”,IEEETrans.PowerDelivery,Vol.30,N.2,pp.931–939,Apr.2015[NEMO]h]p://www.jpowers.co.jp/pr/150608/150608e.pdf. 54

HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

REFERENCES

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HubnetColloquium-StrathclydeUniversity,Glasgow,Scotland(UK)-December7th2016

THANKYOUFORYOURATTENTION!