The Need for MeasurementsIntroduction
Electric traction means a locomotion in which the driving force is obtained from electric motors.
Electric traction will continue to play a dominant role in the Railway since it is an environmentally clean technology compared to diesel traction and also its running cost is low.
There are many advantages of electric traction over other forms of locomotion.
Technical Seminar
ELECTRICAL TRACTION
Equipment should be capable of overloads for short periods
The wear caused on the track should be minimum
Braking should be possible without excessive wear on the brush
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ELECTRICAL TRACTION
Advantages
Cheapness, Acceleration & Braking, Cleanliness, Maintenance Cost, Starting time, High starting time, Braking, Saving in high-grade coal, Better co-efficient of adhesion
Disadvantages
Electrically operated vehicles have to move only on electrified track
For braking & control, additional equipments required
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ELECTRICAL TRACTION
(b) Single phase standard frequency system
(c) Single phase low frequency system
(d) Single phase to three phase system [Kondo system]
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ELECTRICAL TRACTION
Advantages & Disadvantages of 25 kV A.C. System Over D.C. System
Advantages
Starting efficiency
Disadvantages
Produces interference with telecommunication lines
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ELECTRICAL TRACTION
Technical Seminar
ELECTRICAL TRACTION
Review Of Existing Electric Traction In INDIA
Before independence in our country electric trains are working in western region near Bombay & in southern region Madras.
The Tram cars, however were also working in some cities.
All these system operated & still operating on D.C. supply of 1500 V & 600 V for trains & trams respectively.
Technical Seminar
ELECTRICAL TRACTION
Pantograph
Braking Characteristics
If any electric motor is to be stopped, electric supply to it is disconnected.
In this way, the motor shall take long time to stop, as the motor shall continue to rotate due to inertia.
Some braking system must be used so that it stops within the pre-determined short time.
A good braking system must posses the following features
It should be fast and reliable.
The braking force must be capable of being controlled
Kinetic energy of the rotating parts of the motor and its driven machine must be suitably dissipated & suitable means must be provided.
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ELECTRICAL TRACTION
Advantages
Higher speed can be maintained
Heat produced during braking is not harmful
It is free from fires and is smoother
Disadvantages
It can stop the motor but it cannot hold it stationary.
It cannot be applied to all motors
Its initial cost is very high.
Technical Seminar
ELECTRICAL TRACTION
Conclusion
India with its large railway network and the growth of large metropolitan centers is building up a large market for railway transport equipment.
Clean technologies due to environmental considerations.
Energy conservation to minimise wastage of power. Faster/reliable railway transportation.
The success of space, defence and atomic energy can be replicated by the Railways also.
Technical Seminar
ELECTRICAL TRACTION