GOVERNMENT POLYTECHNIC COLLEGE

KOTA(RAJASTHAN)

RAILWAYELECTRICTRACTIONANDPOWERSYSTEM
ELECTRICALENGINEERING

SUBMITTEDBY:-
SUBMITTEDTO:- RITESH NAGAR
ELECTRICAL 1st YEAR
DEPARTMENT ELECTRICAL ENGINEERING
GOVT. POLYTECHNIC COLLEGE
KOTA, RAJASTHAN

DEPARTMENTOFELECTRICALENGINEERING
2025-26
 INDIAN RAILWAYS
ELECTRICTRACTIONSYSTEM
 TABLEOFCONTENTS

ELECTRICTRACTIONSYSTEM

1. HistoryOfRailwayTractionSystem
2. Introduction
3. WhyUseOfElectricTraction???
4. TypesOfElectricTraction(AC,DCAndMultiTractionSystem)
5. AdvantagesOfACAndDCTractionSystem
6. SystemOfTrackElectrification(SingleAndCompoundCatenary)
7. Typesofcurrentcollectors
8. OHE
9. PSI
10. OHECantileverpostsandtypes
11. TowerWagon
12. Conclusion
13. References
HISTORYOFRAILWAYTRACTIONSYSTEM

• The year 1881 saw the birth of the first electric Railway run by a German Engineer
WernerVanSiemensusingboththerailstocarrythecurrent.Findingthisalittletoo
dangerous, Siemens soon adopted the overhead electric wires.
• Electric traction was introduced on Indian Railways in year 1925 on 1.5 KV DC and
the first electric train ran between Bombay's Victoria Terminus and Kurla along the
Harbour Line of CR, on February 3, 1925, a distance of 9.5 miles, flagged off the
then Governor of Bombay Sir Leslie Orme Wilson.

Fig.1IndianRailway
INTRODUCTIONOFTRACTIONSYSTEM

Theprocessofmovinganyvehicleiscalledtraction.Iftheelectricenergyisusein
this process is called electric traction.

Classified broadlyintogroupsnamely:

1. Non-Electrictractionsystem/MechanicaltractionSystem:-

Tractionsystemwhichdonotinvolvetheuseofelectricitysuchassteamenginedrive, IC engine
drive etc.

2. Electrictractionsystem:-

Thesystemwhichuseelectricalpowerfortractionsystemi.e.forrailways,trams,
trolleys,etc.iscalledelectricaltraction.
WHYUSEOFELECTRICTRACTION???

(1) Cheapness:-Lowoperationcost

(2) Cleanliness:-Smokeandgasfree

(3) Maintenancecost:-50%lessthanothersteamengines

(4) Startingtimeandspeed:-Withoutlossoftime.

(5) Highstartingtorque:-UsesofD.C&A.Cseriesmotor-veryhighstartingTorque.

(6) Braking:-Regenerativebreakingisusedwhichfeedsbackenergy.

(7) Savinginhighgradecoal:-Savingofnon-renewableenergysource.
TYPESOFELECTRICTRACTIONSYSTEMS
DCTRACTIONSYSTEM

• DCtractionunitsusedirectcurrentdrawnfromconductorrailoranoverhead….
• Themostpopularlinevoltagesforoverheadwiresupplysystems15kVDCand 30kV DC.
• 600V-750VDCvoltrangeisusedforthirdrailsystems(additionalrailisprofor supplying
electricity to train and is called conductor rail).

Fig.2DCTractionSystem
ACTRACTIONSYSTEM

• ACTractionunitsdrawalternatingcurrentfromanoverheadline.

• TypicalVoltagesUsedare:-

(1) 25kVAC,50Hz.
(2) 25kVAC,60Hz.

Fig.3ACTractionSystem
MULTITRACTIONSYSTEM

• Multi-systemtrainsareusedtoprovidecontinuousjourneysalongroutesthatare
electrifiedusingmorethanonesystem.
• Onewaytoaccomplishthisisbychanginglocomotivesattheswitchingstations.
• Thesestationshaveoverheadwiresthatcanbeswitchedfromonevoltageto another.
• Anotherwayistousemulti-systemlocomotivesthatcanoperateunderseveral
differentvoltagesandcurrenttypes.
• InEurope,itiscommontousefour-systemlocomotives(1.5kVDC,3kVDC,15kV
16%HzAC,25kV50HzAC).
ADVANTAGESOFACTRACTIONANDDCTRACTIONSYSTEM

ACTRACTIONSYSTEM:-

• EfficientForLongDistance.
• LowerMaintenance.
• HighSpeedAndPower.

DCTRACTIONSYSTEM:-

• HighStartingTorque.
• SimpleControl.
• LessElectricInterference.
SYSTEMOFTRACKELECTRIFICATION

Trolley wire or contact wire – suspended with minimum of sag so that contact
between the trolley wire and current collector can be maintained at higher
speeds.
Thiswireissupportedbyanotherwireknownascatenary.

• TwodifferenttypesofCatenaryconstructioncanbeused:-

1. SingleCatenary
2. CompoundCatenary
SINGALCATENARY

• Providedforspeedsupto120kmph.
• Spanofcatenarywire45-90mandsagof1-2m.
• RelativelyCheaper.
• LessMaintenance.
• Suitablewheretrafficisdensermoreandoperatingspeedsarelow.

Fig4.SingleCatenary
Fig.5SingleCatenary
COMPOUNDCATENARY

• Providedforspeedsranges190-224kmph.
• Additionalwirecalledintermediatewireisusedtoincreasecurrentcarrying
capacityi.e.,tohaveincreasedtrafficdensity.

Fig.6CompoundCatenary
Typesofcurrentcollector

(1) Bow Collector :- A bow collector is one of the three main devices used on
tramcars to transfer electric current from the wires above to the tram below. It
has now been largely replaced by the pantograph.

Fig.7BowCollector
(2) Pantograph Collector :- Main function is to maintain the link between overhead
contact wire and power circuit of the locomotive at varying speeds in different climate
and wind conditions.

Fig.8PantographCollector
OHE(OverheadEquipment)
OHE, also known as Overhead Catenary System (OCS) or Overhead Line (OHL), is
the intricate system of wires and supporting structures that supplies electricity
to an electric train. It’s the “fuel line” for the electric locomotives and EMUs
(Electric Multiple Units).

Components :- The main components of OHE include the catenary wire, the
contact wire, droppers, and various insulators and fittings.

Function :- A pantograph on the roof of the electric locomotive makes contact

Fig.9OHE
PSI(PowerSupplyInstallation)
PSIreferstotheground-basedelectricalinfrastructureresponsibleforsupplying
powertotheOHE.It’sthe“powerstation”fortherailway.

Components :- PSI includes Traction Sub-Stations (TSS), Sectioning Posts (SP), and
Sub-Sectioning Posts (SSP). These installations contain critical equipment like
transformers, circuit breakers, and isolators.

Function :- PSI receives high-voltage power from the national grid and steps it down
to the required voltage (e.g., 25 kV AC) for the OHE. It also provides for the
sectionalizetion and protection of the OHE.

Fig10.PSI
OHECantileverPostsandTypes
A cantilever is a structural member that holds the OНЕ assembly (contact wire,
catenary wire, and droppers). It extends from a mast and is insulated to prevent
electrical current from flowing to the support structure.

Function:-Cantileversmaintaintheproperposition,height,andtensionoftheOHE
wires,ensuringsmoothcurrentcollectionbythepantograph.

TypesofStructures:-While"cantileverports"maybeaslightmisnomer,theterm
likelyreferstothedifferenttypesofsupportstructuresusedfortheOHE.
Theseinclude:-

(1) Mast:-Asinglepoleorstructure usedtosupporttheOHEforoneortwotracks.

(2) Portal :- A large structure used to support OHE for multiple tracks (2 to 8 or more)
where it’s not practical to erect separate masts. Portals are often classified into types
based on their span, like N, O, and R types.

(3) Two-TrackCantilever(TTC):-AstructuredesignedtosupporttwoOHElineswhere
afullportalisnotnecessary.
 Fig.12 Portal

Fig.11Mast Fig.13Two-TrackCantilever(TTC)
Fig.14TwoTrackCantilever
TowerWagon
A tower wagon is a specialized self-propelled rail vehicle used for the
maintenanceand repair of the OHE. It’s essentially a mobile workshop for the
overhead lines.

Features:-It’sequippedwithacraneandamovableplatformthatcanberaisedand
loweredtoallowworkerstosafelyaccessandworkontheoverheadwires.

Function:-Towerwagonsareessentialforbothroutineinspectionsandemergency
repairsoftheOHE,ensuringthecontinuousandsafeoperationofelectrictrains.
Fig.15TowerWagon
Conclusion

Therailwaytractionsystemisacriticalcomponentofmodernrailtransportation,
enablingefficientandreliablemovementoftrains.Thissystemplaysavitalrolein:-

1. Improvingefficiency:-Optimizingenergyconsumptionandreducingoperatingcosts.
2. Enhancingreliability:-Ensuringconsistentandreliabletrainoperation.
3. Increasingcapacity:-Enablingmoretrainstooperateonexistinginfrastructure.

By leveraging advancements in railway traction systems, the rail industry can continue
to improve efficiency, reduce environmental impact, and provide high-quality
transportation services.
REFERENCES

• Englishm.wikipedia.org
• wwwlinkedin.com
• Learnmech.com
• Scribed.com
Thank
You