The document discusses electrical traction systems used in rail transport. It describes the key components of diesel-electric and electric traction systems including the diesel engine, alternator, and traction motors. For electric systems, it explains how alternating current is drawn from overhead lines and converted to direct current to power DC series motors or used directly to power AC induction motors. It also discusses multi-system locomotives that can operate on different electrification systems and the use of pantographs to draw power from overhead lines.

1. ELECTRICAL TRACTIONS
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VAIRAMUTHU J

3. Diesel engine Function
 The diesel used as fuel
 Diesel is used to run the alternator
 Power is generated from the alternator
 The power is fed to the traction motor
 In case of AC traction motor the generated power is given to the transformer and
given to the AC traction motor
 In case of DC traction motor the generated power is given to the rectifier unit
 The AC is converted to the DC and given to the DC traction motor
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4. Traction Motors
 DC Series motor
 1 phase AC series motor
 3 phase Induction motor
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5. DC Series Motor
 Develops high torque at low speed
 Develops low torque at high speed
 Torque is independent of the line voltage and thus unaffected by
the variations in the line voltage.
 exact requirement of the traction units
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6. 1 phase AC series motor
 Starting torque is lower than DC series motor
 Due to poor power factor at starting
 This motor has surpassed the DC series motor in terms of size,
 weight cost for the same rating.
 Maximum operating voltage is limited to 400 Volts.
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8. 3 phase Induction motor
 Provides constant speed operation,
 Developing low starting torque drawing high starting current and
 complicated control networks makes it unsuitable for electric
traction work.
 Automatic regeneration is the main advantage in electric traction
with this motor.
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10. Electrical Traction System
 Locomotion obtained from electric traction motors via tractive force
 Uses - railways, trams, trolleys etc.
 3-Phase Induction motors and DC series motors are used
 Both have high starting torque
 High speed acceleration.
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11. Electrical Tractions - Types
 DC Traction
 AC Traction
 Multi Systems
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12. DC - Tractions
 DC drawn from either a conductor rail or an overhead line.
 Most popular line voltages– 1500V DC and 3000V DC.
 Third rail systems - 600V DC–750V DC
 Low-voltage, series-wound, DC motor is suited to railroad traction
 Being simple to construct and easy to control.
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14. AC - Traction
 AC from an overhead line is drawn
 Typical Voltages Used are:-
15 kV AC, 16⅔ Hz (16.7 Hz)
25 kV AC, 50 Hz
25 kV AC, 60 Hz
 Fewer substations are required
 The lighter overhead current
 supply wire can be used
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15. Multi - System
 Changing of traction types used
 In order to reduce the traction type to each and every station this system was introduced
 Here the station contains both AC & DC over head lines
 Train engine can use both power at a time
 2 way usage is not possible
 In Europe, it is common to use four-system locomotives
1.5 kV DC
3 kV DC
15 kV 16⅔ Hz AC
25 kV 50 Hz AC
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17. System of Track Electrification
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
Types
 Single catenary
 Compound catenary
Trolley
wire
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19. Pantograph Collector
Main function
 Maintain the link between overhead contact wire and power
circuit
 Different climate and wind conditions is suitable
 This can be lowered or raised from cabin by air cylinders.
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20. AC – Traction - Advantages
 motors used in electric traction have a very high starting torque
 No exhaust fumes or carbon emissions
 Less noise pollution (quieter operation)
 The maintenance cost of an electric locomotive is nearly 50% of that for a steam
locomotive
 Usage of regenerative braking is possible
 Supply is plenty of the train
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21. AC – Traction - Disadvantages
 Significant capital cost of electrification
 Increased maintenance cost of the lines
 Overhead wires further limit the clearance in tunnels
 Upgrading brings significant cost,
 Railway Traction needs immune power, with no cuts
 Warranting duplication of Transmission and Distribution systems
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22.  https://www.youtube.com/watch?v=tnHRpCsm160
 https://www.youtube.com/watch?v=FqKPo6SrRdA

23. Thank you