1. Growing electricity demand in India due to population growth, urbanization, and digitalization is straining the existing power transmission infrastructure. High Temperature Low Sag (HTLS) conductors can help increase the capacity of existing transmission lines by 100% without requiring modifications to transmission towers. 2. HTLS conductors have enhanced current carrying capacity and allow transmission lines to operate at higher temperatures compared to conventional conductors. This helps utilize existing transmission corridors more efficiently to support India's growing electricity needs and implementation of smart grid technologies. 3. Major HTLS conductor types discussed are STACIR, ACCC, ACSS, and TACSR. Indian manufacturers like Sterlite Power and Apar Industries are producing these conduct

1. 1
HTLS CONDUCTOR ---- A WAY AHEAD FOR SMARTGRIDS TO CATER LOAD
DEMANDS
K R Suri , SirajBhattacharya
ABSTRACT
Growingdemandof electrical energy,urbanisationandrow issueshave forcedtosearchfor
alternativestocaterthe futuristicdemandof the country.Inthispaperefforthasbeenmade to
understanddevelopmentanduse of HTLS conductor,that how it can technicallyhelpinutilising
existingtransmissionlinesfortransferof more powerandsupportingSMARTGRIDS execution.

2. 2
Growingdemand ofelectrical power
Comfortinlife throughelectrical gadgetsisbeinggiventopprioritybythe civilisedcummodern
society.Thisisfurthercumulatedbypopulationgrowthandurbanisation.Notonlythismodernauto
controlledsystemsforincreaseinproductivityalsodemandforareliable cum qualityinelectrical
power.inthe recentyearsthere hasbeenadrasticchange in Indiansociety.People have become
educatedthroughmediafortheirrightsandlawsapplicable onthe land.Gone the dayswhen
transmissionlineswere treatedasessential commoditytobe laidthroughanyarea or fieldand
people were notallowedtostopit.
Trendingdemand
Since independence there hasbeenincreasingtrendinpercapitaconsumption.Exhibitbelow shows
trend,howeveritisverylessascomparedto global level.
Digital cum Make in Indiaplans (SMART GRIDS)
Indiangovernmentworldwide hasgivenacall to start ownproductionsinIndiainplace of importing
readymade products.Our prime ministerhasexpressedinalmostall worldlevel forumsandinvited
multinationalcompaniesandstrongcountriestostartproducts inthe country.This attracts demand
of reliableelectrical power.
Digital Indiatheme alsocallsfora smartgrid technologyimplementationtocompete the growing
competenciesandsecuritysystemsinplace inview of existingthreatof terrorismtothe countryand
world.
Current and futuristicdemand of India

3. 3
At presentapprox.There is1,50,000 circuit Kmsof 400kv & above network.Inwhich37000 mw
interregional and13500mw powerflowsthroughinterregional andHVDCtransmissionnetwork
respectively.Thisisasteptowards one gridone nation& to supportsmartgrid network.
As perCEA, a GOI enterprise.Statusof generationincountryisasbelow.
As perIndiapowersector,lookingtotrendandforecast by2030, demandof countryshall be 9,
75,000 mw.Meaningthere by thatthere is rise indemandof 30,000mw per year.For whichsuitable
transmissioncorridorisrequiredfortransferof powerforlongdistanceswithrespecttothe existing
laws& row. There isdire needforalternates.
Major challenges
Rightof way
Improvementinoperational efficiency
Flexibilityinlineloadingandregulationof power
Measuresto meetchallenge – implementationpart
Increase intr. Voltage
Up gradationof tr. Lines
Up gradationof HVDCterminals
Multi circuittowers
Highsurge impedance loadinglines
Compacttowers
Use of HTLS conductor
Land reduction
Use of facts/svc/statcom
Conditionbasedmonitoring

4. 4
1200 kv stations
Meetingchallenges---- use ofHTLS conductor in lines
To enhance capacityof existingtransmissioncorridorHTLSconductorhas emergedasa prominent
solution.HTLSmeanshightemplowsag conductor.Meansreplacingthe oldconductorby thisnew
developone increasecapacityby100% usingsame corridor andtowers.Occasionallymayrequire
strengtheningof existingtowersforlifeenhancement.Theseare alsocalledashighperformance
conductors(HPC).Itis superiorasbelow
RECONDUCTORING
 Enhancedcurrentcarrying capacityfor the same diametercumweight.
 No modifications tothe existingtowers.(applicable toalmostall lines)
NEW LINES
 Enhancedcurrentcarrying capacity.
 Reductioninperunittransmissioncost.
 Higherresistance tocorrosion.
 Reservedcapacityforfuture demand.
GREEN SOLUTIONS
 Low lossleadingtolowercarbonemissions.
 Run at lowertemperature forthe same current.
LIMITATIONS
*Special attentionrequiredduringinstallations.
* Hardware alsorequiredmeetinghightempConditions.
* Highinitial cost
ALTERNATIVES HAVE BEEN DEVELOPED AND PRODUCED AS EQUILENT.
There are mainlyfourtypesof HTLS conductors.
 STACIR
 ACCC
 ACSS
 TACSR
 GAP ( STACIR)
STACIR
It issuperthermal AL.conductor INVARreinforced.Invarisametal alloywith36% NI.insteel.
Outerlayerscomposedof superthermal aluminium(STAL)alloy.Enhancescapacityby100% as

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comparedto equivalentACSR.Butlossesare alittle higher. Worksup to 200 degrees
centigrade.Coefficientof linearexpansionis3.7x10_6/cen.As compare to ACSR11.5X10_6/cen.
ACCC
It is hybridcarbonand glassfibre core for strengthwrappedoverbytrapezoidal shapedannealed
aluminiumstrands.Loadcarryingcapacityincreasestodouble the equivalentsize ie unitweightis
same,lossesare reducedto40%. Carbon emissionisalsoless. ACSRworksupto 85 deg.It worksup
to 200 degrees.Itresistsanddoesnotrustor cause electrolysiswithAL.conductororcomponents
ACSS
Al.conductorsteel supported.Itismade upof annealedaluminiumwire withinnercore of
Galfan(Zn 5% & Al.Mischmetal ) coatedsteel wire.Itcan take up to 250 deg.But sag increases
at maximumtemperature againstconventional.Itisverymuchsuitable forhighloadlinesor
highfluctuationsof load(damping)
TACSR
This is again a high amp capacity conductor suitable for large power carrying transmission
lines.Outerlayer strands are composedof thermal resistance al. alloy with steel reinforced.It
is suitable for newlines. Capacity is enhancedby 50 to 60% as compared to conventional
conductor.

6. 6
GAPTACSR
This is again a modifiedor improvedversionof TACSR. Inner layer isfilledwithgrease
SAND BLASTED CONDUCTOR
Normallyconductors are annealedor hard. It is hydrophobicin nature. To make it is hydrophilicin
nature its top surface issand blastedso as to make it hydrophilicand surface becomesrough. Due
to this there is reductionin noise level to 7db. Picture belowexhibitsboth type of conductors. It is
comparativelycostlier,hence always made to order.
Hydrophobic Hydrophilic
TECHNICAL COMPARISON

7. 7
PREFERRED SOLUTIONS

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Installationsof suchconductorhave provensuccessstoryinIndiaandacross globe.Now inIndia,It
isbeinginstalledbyvariousutilitiesfrom33kvto 400kv level innew andexisting lines.
Manufacturing inIndia
Followingsare the majormanufacturersandexportersasperbrand name
Sterlite power
Apar industries.
BIBLIOGRAPHY ---
D/C – Doublecircuit
CEA – Central electricity authority
MOP – Ministry of power,Govt.of India
GOI --- Govt.of India
HTLS – High temperaturelowsag conductor
REFRENCES
Sterlite conductor,
JS powersystems,productcatalogue,Japan.
Lamifil NV,productcatalogue,Belgium
De Angelli Prodditi, s.r.l,Italy.
ABOUT AUTHOURS
K R SURI is retired general managerfrom Power Grid CorporationofIndialtd& consultantwith
Sterlite power, India.
SirajBhattacharya,Head global businesshead,Sterlite power ltd.