Electric traction
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- 2. CONTENTS • Introduction • Electric Locomotive Divisions • Transmission System • Traction System • Parts of Locomotive • Advantages • Conclusion 2
- 3. •An electric locomotive is a locomotive powered by electricity from overhead lines, a third rail or on-board energy storage such as a battery or fuel cell. •Electric locomotive is classified into two categories. The first type of vehicle receives power from a distribution network while the second type of vehicle generates own power. In the second category comes a diesel engine electric drive. INTRODUCTION 3
- 4. DIVISION OF ELECTRIC LOCOMOTIVE Electric Locomotive Transmission Traction System Internal Working 4
- 6. 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. TRACTION 6
- 7. CIRCUIT BREAKER The high voltage circuit breaker is special type of electro pneumatic contactor mounted on the roof of the loco. The electrical equipment of the loco is connected to or disconnected from the OHE by means of the circuit breaker. 7
- 8. BLOCK DIAGRAM OF LOCOMOTIVE 8
- 9. TRANSFORMER • An essential requirement for locomotives and trains using AC power, where the line voltage has to be stepped down before use on the train. • Normally transformers used are of rating 5600 kva to 7200 kva PARTS OF ELECTRIC LOCOMOTIVE 9
- 10. RECTIFIER •A rectifier consist of thyristors and diodes which is used to convert AC to DC. •Instead of conventional bridge rectifiers thyristors are used for smooth operation at power level. •A modern locomotive usually have at least two, a "Main Rectifier" for the power circuits and one or more for the auxiliary circuits. 10
- 11. DC LINK •Used on modern electronic power systems between the single phase rectifier and the 3-phase inverter. • It is easier to convert the single phase AC from the overhead line to the 3-phase required for the motors by rectifying it to DC and then inverting the DC to 3-phase AC. 11
- 12. ARNO CONVERTOR • Arno converter is a device which convert single phase AC in to three phase AC. • The three phase supply is needed for the three phase induction motors which are used in blowers, exhausters an oil pumps. • Arno converter is rotating device. 12
- 13. TRACTION MOTORS •Direct-current motors with series field windings were the oldest type of traction motors. •These provided a speed-torque characteristic useful for propulsion, providing high torque at lower speeds for acceleration of the vehicle, and declining torque as speed increased. •By arranging the field winding with multiple taps, the speed characteristic could be varied, allowing relatively smooth operator control of acceleration. A further measure of control was provided by using pairs of motors on a vehicle; for slow operation or heavy loads, two motors could be run in series off the direct current supply. 13
- 14. • A variant of the DC system was the AC operated series motor, which is essentially the same device but operated on alternating current. • Since both the armature and field current reverse at the same time, the behavior of the motor is similar to that when energized with direct current. • To achieve better operating conditions, AC railways were often supplied with current at a lower frequency than the commercial supply used for general lighting and power; special traction current power stations were used, or rotary converters used to convert 50 or 60 Hz commercial power to the 16 2/3 Hz frequency used for AC traction motors. Continued… 14
- 15. ADVANTAGES Electricity is used to eliminate smoke and take advantage of the high efficiency of electric motors; however, the cost of railway electrification means that usually only heavily-used lines can be electrified. The power for electric locomotives can come from clean and/or renewable sources, including geothermal power, hydroelectric power, nuclear power, solar power and wind turbines. Electric locomotives benefit from the high efficiency of electric motors, often above 90%. Additional efficiency can be gained from regenerative braking, which allows kinetic energy to be recovered during braking to put some power back on the line. Newer electric locomotives use AC motor- inverter drive systems that provide for regenerative braking. 15
- 16. CONCLUSION Finally, I can conclude that electric locomotives are playing a vital role in railway system till now. The use of electric locomotives primarily came in order to reduce problems of smoke pollution. Though electric locomotives are more efficient than steam and diesel locomotives, electrification of railway lines is expensive. For this reason, electric locomotives are used mainly for busy passenger lines. 16
- 17. • http://www2.hesston.edu/Physics/electricloco/eleclocop.html (12/4/15) • http://24coaches.com/locomotive-working-india/(12/4/15) • http://www.ehow.com/how-does_4898637_electric-train- work.html(10/4/15) • http://science.howstuffworks.com/transport/engines- equipment/electric locomotive.htm(08/4/15) • http://physics.stackexchange.com/questions/150033/how- does-this-simple-electric-train-work(10/4/15) REFERENCES 17
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