2. Details Of Company
South Central Railways
Mentor : Mr. V. Samson Deva Kumar
Project Manager
Internship Duration: 10 AUG 2022 TO 10 SEP 2022
(1 Month)
Address:
South Central Railway
Women’s Welfare Organisation
Opp. Railway Hospital, Near Railway Station
Vijayawada-520001, Andhra Pradesh
Phone:0866-2768283, Rly: 68283
E-mail: eworldscrwwo@gmail.com
https://maps.app.goo.gl/HqGJ1iVJtnrbuRnE6
2
3. List of Content’s
1.Introduction to Electric Locomotive
2.Working Principle
3.Classification
4.Components in Electric Locomotive
5.Conclusion
3
4. 1.Introduction to Electric Locomotive
• An Electric locomotive is a locomotive powered
by electricity from overhead lines
• Electric locomotives benefit from the high efficiency of
electric motors, often above 90% (not including the
inefficiency of generating the electricity).
• Additional efficiency can be gained from regenerative braking,
which allows kinetic energy to be recovered during braking to
put power back on the line. Newer electric locomotives use
AC motor-inverter drive systems that provide for regenerative
braking
• Electric locomotives usually cost 20% less than diesel
locomotives, their maintenance costs are 25-35% lower, and
cost up to 50% less to run.
4
5. Introduction to Electric Locomotive
• The chief disadvantage of electrification is the high cost for
infrastructure: overhead lines or third rail, substations, and
control systems.
• The first known electric locomotive was built in 1837 by
chemist Robert Davidson of Aberdeen, and it was powered
by galvanic cells (batteries)
• The first practical AC electric locomotive was designed
by Charles Brown, then working for Oerlikon, Zürich. In
1891, Brown had demonstrated long-distance power
transmission, using three-phase AC, between a hydro-electric
plant at Lauffen am Neckar and Frankfurt am Main West, a
distance of 280 km.
5
7. Working Principle
• 25 kV overhead AC supply is stepped down with the main
transformer in the locomotive and fed to a front end (line) twin 4-
quadrant line converter where AC is converted to DC through
Pulse Width Modulation( PWM) thus achieve unity power factor.
• This supply is linked with an input side converter through DC link
which is a reservoir of energy.
• Drive converter (VVVF Converter) converts DC supply into 3 phase
which is then fed to 3 phase traction motors.
• Gate turn off (GTO) thyristors are used in converter/inverter.
• The output of Drive converter (inverter) is Variable Voltage Variable
Frequency (VVVF) supply which helps in controlling the starting
and running torques of three-phase traction motors to suite traffic
requirements
7
9. Classification
Locomotives were classified by track gauge, motive power,
function and power (or model number) in a four- or five-letter
code. The first letter denotes the track gauge. The second letter
denotes motive power (diesel or electric), and the third letter
denotes use (goods, passenger, mixed or shunting). The fourth
letter denotes a locomotive's chronological model number.
A locomotive may have a fifth letter, generally denoting a technical
variant, subclass or subtype: a variation in the basic model or
series, or a different motor or manufacturer. Under the new system,
the fifth letter further refines horsepower in 100-hp
increments: A for 100 hp, B for 200 hp, C for 300 hp and so on. A
WDP-3A is a 3,100 hp (2,300 kW) locomotive, and a WDM-3F is
3,600 hp (2,700 kW).
The system does not apply to steam locomotives, which are no
longer used on main lines. They retain their original class names,
such as M- or WP-class.
10. Syntax
First letter (gauge) Second letter (motive power) Third letter (job type)
W – Broad gauge (wide) –
5 ft 6 in (1,676 mm)
D – Diesel G– Goods
Y – Metre gauge (yard) –
1,000 mm (3 ft 3+3Ú8 in)
C – DC electric (DC overhead line) P – Passenger
Z – 2 ft 6 in (762 mm) narrow
gauge
A – AC electric (AC overhead line) M – Mixed (goods and passenger)
N – 2 ft (610 mm) narrow (toy)
gauge
CA – DC and AC (AC or DC
overhead line);
CA is considered one letter
S – Shunting (switching)
B – Battery (rare) U – Multiple unit (electric or diesel)
11. In WDM 3A,
W denotes broad gauge;
D denotes diesel power;
M denotes mixed use (goods and passenger service), and
3A denotes 3,100 hp (2,300 kW) (3,000 + 100).
In WAP 5, W is broad gauge; A is AC electric; P is
passenger service, and 5 indicates that the locomotive is the
fifth model used
Example
12. Components in Electric Locomotive
• Pantograph
• Transformer
• Compressor
• Circuit breaker
• Contactor
• Electromechanical relay
• Insulator
• Tap changer
• Rectifier
• Gate turn off (GTO) thyristor
• Insulated-gate bipolar transistor (IGBT)
• Inverter
• Converter (DC to DC)
• Cooling fan
• Traction (AC or DC) Motor
12
16. Conclusion
By this Industrial Internship in south central
railways we have come to know about the
functioning of railways in Vijayawada.
We have observed and learned many aspects in
safety measures signal & communication system
,maintenance and service system of coaches and
trains, loco pilot training and functions ,train
functioning and tracking systems, electrical
traction system , sub stations of railways in
Vijayawada division
16
