The document discusses electric traction systems. It begins by defining electric traction as a locomotion system where the driving force is obtained from an electric motor. It then covers major classifications of traction systems including non-electric and electric examples. The document also outlines requirements of an ideal traction system and discusses merits and demerits of electric traction. It provides details on different electric traction supply systems and speed variation considerations.

1. ELECTRIC TRACTION
S.RAGUL,
AP/EEE
DEPARTMENT OF EEE
KONGUNADU COLLEGE OF
ENGINEERING & TECHNOLGY
electric traction KONGUNADU COLLEGE OF ENGINEERING & TECHNOLOGY
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Content:
 Introduction to electric traction
 Major classification, requirements, merits, demerits, supply
system, speed variation.
 Factors affecting energy considerations, traction features, recent
trends
 References

2. INTRODUCTION:
 The locomotion in which the driving force is
obtained from electric motor is called the electric
traction system.
 There are various system of electric traction
existing such as electric train, trolley buses,
diesel-electric vehicles and gas turbine electric
vehicles
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3. ELECTRIC TRACTION SYSTEM
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4. MAJOR CLASSIFICATIONS OF
TRACTION
 Non-electric traction:
examples
steam engine drive
ic engine drive
 Electric traction:
examples
diesel electric drive
gas turbine electric drive
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5. REQUIREMENTS OF AN IDEAL TRACTION
SYSTEM
 The starting tractive effort should be high so as
to have rapid acceleration.
 The wear on the track should be minimum.
 The equipments should be capable of
withstanding large temporary loads.
 Speed control should be easy.
 Pollution free.
 Low initial and maintenance cost.
 The locomotive should be self contain and able to
run on any route.
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6. 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.
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7. 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.
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8. DIFFERENT SYSTEMS OF TRACTION:
 Direct steam engine drive
 Direct IC engine drive
 Steam electric drive
 IC engine electric drive
 Petrol electric traction
 Battery electric drive
 Electric drive
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9. IC ENGINE ELECTRIC DRIVES
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10. 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
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11. SPEED TIME CURVE FOR TRAIN MOVEMENT
 Acceleration
 Constant acceleration
 Speed curve running
 Free run or constant speed period
 Coasting period
 Retardation or braking period
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12. TYPICAL SPEED TIME CURVES FOR
DIFFERENT SERVICES
 Urban or city services
 Sub urban services
 Main line services
TYPES OF SPEED IN TRACTION
 crest speed
 Average speed
 Schedule speed
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13. FACTORS AFFECTING ENERGY
CONSUMPTION
 Distance between the stops.
 Train resistance
 Acceleration and retardation.
 Gradient
 train equipment.
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14. TRACTION MOTORS
 DC series motor
 Ac series motor
 Three phase induction motor
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15. TRACTION MOTOR 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.
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16. RECENT TRENDS IN ELECTRIC TRACTION
 Tap changer control
 Thyristor control
 Chopper control
 Micro processor control
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17. MICRO PROCESSOR CONTROL
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18. Conclusion:
 The Major classification of electric traction, requirements, merits,
demerits, supply system, speed variation, factors affecting energy
considerations, traction features, recent trends is explained in detail
with suitable diagrams.
References:
 N.V. Suryanarayana, “Utilisation of Electric Power”, Wiley
Eastern Limited, New Age International Limited,1993.
 J.B.Gupta, “Utilisation Electric power and Electric
Traction”, S.K.Kataria and Sons, 2000.
 G.D.Rai, “Non-Conventional Energy Sources”, Khanna
Publications Ltd., New Delhi, 1997
 C.L.Wadhwa,“Generation, Distribution and Utilisation of
Electrical Energy”, New AgeInternationalPvt.Ltd., 2003.
 B.H.Khan, “Non Conventional Energy Resource”, Tata
Mcgraw hill eductation pvt ltd.., 2009
 VThiyagaran, “Electric Energy Generation, Utilization and
Conservation”, Lakshmi publications.,2016
 Other Web Sources
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