Скачать или смотреть Traction types of Diesel-electric Locomotive by Abdul Malik

Lecture Content (L-4)
What is Alternator/Diesel Generator ?
The alternator generates AC electricity which is used to provide power for the traction motors mounted on the trucks (bogies)
In older locomotives, DC generator was used to produce direct current which was used to provide power for DC traction motors
Latest development was the replacement of the generator by the alternator but still using DC traction motors.  The AC output is rectified to give the DC required for the motors
Main output from the diesel engine is transmitted by the drive shaft to the alternators at one end and the radiator fans and compressor at the other end.
Traction types of DE Locomotive
Diesel-electric locomotives come in three varieties
DC - DC (DC generator supplying DC traction motors)AC - DC (AC alternator output rectified to supply DC motors)  AC - DC - AC (AC alternator output rectified to DC and then inverted to 3-phase AC for the traction motors) .
Auxiliary Equipment
This includes Auxiliary Generator, exciter which is used to operate smaller equipment on locomotive, battery charging , starting of locomotive, traction motors blower, dust blower, air compressor, air conditioning, head lights
Locomotive is started with batteries providing the power to turn a starter motor which turns over the main engine and ignition process is started
In older locomotives fitted with DC generators instead of AC alternators, the generator was used as a starter motor by applying battery power to it

Braking Equipment
Rolling stock used to have 2 braking system, Air brake and vacuum Brake
Air brake is most effective braking system and is now used on maximum rolling stock
Vacuum braking system used to have less braking efficiency
All the D.E locomotives used to have air brake system since put is operation
All the High capacity goods stock is equipped with air brake system.

Working Principle of Air Braking System
Locomotive having main air reservoir is charged with compressed air at 110 - 125 PSI or 8-9 bars through compressor.
The train/trailing load is charged with 70 PSI or 5 bars till the end of train.
For initiating of brake application, a drop of 6 PSI is made and brake application is made.
For full service brake application, a drop of 21 PSI is made to stop the train.
For emergency brake application, all the pressure is dropped to zero.