This presentation revolves around principle of Traction drives,basics idea about locomotives,catanary,panto-graph and speed-Time curve.

1. BASICS OF
ELECTRIC TRACTION
DRIVES
Guided By Prepared By.:
Mrs. Najma S. Nizami Vivek Nirmal(244)

2. CONTENT :
 Introduction
 Classifications Of Traction Drives
 Requirements Of A Traction System
 Merits And Demerits OF Electric Traction
 Electric Locomotives and its component
 Dc Traction Motor
 Duty Cycle Of Traction Drives
 Recent Trends In Electric Traction Control
 References

3. INTRODUCTION
 The Locomotion In Which The Driving Force Is
Obtained From Electric Motor Is Called an ELECTRIC
TRACTION DRIVE.
 Traction Motor Refers To An Electric Motor Providing
The Primary Rotational Torque Of A Machine, Usually
For Conversion Into Linear Motion (Traction).
 There Are Various System Of Electric Traction
Existing Such As Electric Train, Trolley Buses, Diesel-
electric Vehicles And Gas Turbine Electric Vehicles.

4. IN INDIA, ELECTRIFICATION IN TRACTIONS ARE CONDUCTED
WITH THREE TYPES OF LOCOMOTIVES.
1. Using Single Phase A.C. Series Commutator Motor.
2. Using D.C. Motor With Tapped Transformer And Rectifier.
3. Using Phase Converter And Induction Motors.
EXISTING TRACTIONS SYSTEM USES D.C. MOTORS.
1. The 25 KV Over Head Voltage Is Step Down To 2000 V With The
Help Of Step Down Transformer.
2. Rectifier Rectifies This A.C. Voltage To D.C. Voltage.
3. This Rectified D.C. Voltage Is Used To Operate The D.C. Motors In
Existing System Engine.

5. REQUIREMENTS OF AN IDEAL
TRACTION DRIVE
 High Starting Tractive Effort In Order To Have
Fast Acceleration.
 The Wear On The Track Should Be Minimum.
 Equipment Capable Of Withstanding Large
Temporary Overloads For Short Periods.
 Speed Control Should Be Easy.
 Pollution Free.
 Low Initial And Maintenance Cost.

6. MAJOR CLASSIFICATIONS OF
TRACTION DRIVES
 NON-ELECTRIC TRACTION
1. Steam Engine Drive
2. IC Engine Drive
 ELECTRIC TRACTION:
1. Diesel Electric Drive
2. Gas Turbine Electric Drive

7. SUPPLY SYSTEMS FOR ELECTRIC
TRACTION
 D.C System
 A.C System
 Single Phase
 Three Phase
 Composite System
 Single Phase AC To DC
 Single Phase To Three Phase
(KANDO SYSTEM)

8. MERITS OF ELECTRIC TRACTION
 High Starting Torque.
 Less Maintenance Cost
 Cheapest Method Of Traction
 Rapid Acceleration And Braking
 Less Vibration
 Free From Smoke And Flue Gases Hence Used
For Underground And Tubular Railway.

9. DEMERITS OF ELECTRIC
TRACTION
 High Capital Cost.
 Problem Of Supply Failure.
 The Electrically Operated Vehicles Have To Move
On Guided Track Only.
 Additional Equipment Is Required For Achieving
Electric Braking And Control.

10. ELECTRIC LOCOMOTIVES
Electricity Is Used To Drive The Electric Locomotives.
Two Types Of Vehicles Are Used For Electric Traction.
1. The First Type Of Vehicle Receives Power From A
Distribution Network. These Vehicle Are Used On
Ac Or Dc Power From The Overhead Line. While,
2. The Second Type Of Vehicle Generates Own
Power. A Diesel Engine Electric Drive comes In This
category.

11. COMPONENT OF AN A.C
LOCOMOTIVE

12. CATANARY
 This Is An Overhead Wire Of Special Cross Section which
is used for maintain good contact between current collector
and contact wire. The Catenary Is Supplied At 25 KV;50 Hz
Supply.
 AC Voltage Is Trapped From Catenary By Pantograph.

13. PANTOGRAPH
 Pantograph Is A Current Collecting Device Which Is Mounted
On Both Ends Of Locomotive Roof On Insulator And Collect
The Current From Over Head Extension And Supply It To
Power System Of Locomotive At Various Speed And Different
Climate/Wind Condition Smoothly.

15. THE DC TRACTION MOTOR:
HOW IT DRIVES THE AXLE

16. TRACTION MOTORS (DC MOTOR)
 The Traditional DC electric motor driving a train or
locomotive is a simple machine consisting of a case
containing a fixed electrical part, the stator (called the
stator because it is static and comprising what is called
the field coils) and a moving electrical part, the rotor
(because it rotates) or armature as it is often called.
 As the rotor turns, it turns a pinion which drives a
gearwheel. The gearwheel is shrunk onto the axle and
thus drives the wheels as shown in the diagram above.
 The Traction Motor Consist Of, Four Pole Or Six Pole,
Forced Ventilated Machine Arranged For Axle Mounting
On Sleeve Baring.

17.  Special provision has been made in design of the motors to
ensure the locomotive operates satisfactorily on flooded track,
to max. Flood level of 20 cm , above rail level.
 Generally In Locos There Are Six Traction Motors.
 Three Motors Per Bogies And Each Motor Driving One Axle
Directly Through Gears.
 The Motors M1 To M6 Are Supplied Jointly By The Two Silicon
Rectifiers Connected In Parallel Through Two Contactors.
 Each Rectifier Units Is Connected To Separate Secondary
Winding And Smoothing The Current Thus Rectified In
Carried Out By Means Of Two Smoothing Reactors.

18.  In case of Electric locomotives :-
 WAP-1, WAP-4, WAM-4, WAg-5/6/7 and WCM-1/2/3 used
DC SERIES MOTORS for traction.
 WAP-5/7 and WAG-9 have THREE PHASE INDUCTION
MOTORS for Traction.

19. AC LOCOMOTIVES WITH
DC DRIVES

20. DUTY CYCLE OF TRACTION
DRIVES

21. FEATURE OF TRACTION MOTOR
DRIVE
Electrical Features
 High Starting Torque
 Simple Speed Control
 Regenerative Braking
 Better Commutation
 Capability Of Withstanding Voltage Fluctuations.
Mechanical Features
 Light In Weight.
 Small Space Requirement.
 Robust And Should Be Able To Withstand Vibration.

22. CONCLUSION
No Single Motor Is ideal For Traction Purposes but
DC Series Motors Are Most Suitable For This Work.
 Tap Changer Control
 Thyristor Control
 Chopper Control
 Micro Processor Control
RECENT TRENDS IN ELECTRIC
TRACTION CONTROL

23. REFERENCES
WEBSITES
 http://www.railway-technical.com
 http://en.wikipedia.org/wiki/Traction_motor
 http://www.engineeringexpert.net/Engineering-Expert-Witness-
Blog/?tag=traction-motor
 http://www.circuitglobe.com/electric-traction-drives.html
BOOKS
 Gopal K. Dubey, Fundamental Of Electrical Drives Third Edition ,
Page 302-312
 Singh, K. B. Khanchandani, Power Electronics, Second Edition ,
pages 846-890