1. ROLLING STOCK LOCOMOTIVE WORKSHOP CHARBAGH
LUCKNOW,UTTAR PRADESH
AN INDUSTRIAL TRAINING PRESENTATION ON
POWER TRANSMISSION SYSTEM USED IN MEMU/EMU
SAFE OHE OPERATION PROCEDURE USED IN RAILWAY
Submitted by: Sonali Sharma Submitted to: Er. Wazid Ali
Course: Btech.,4th year Er. Pavan Kr. Singh
Branch: Electrical Engineering
Roll no: 190013095037
2. ROLLING STOCK LOCOMOTIVE WORKSHOP
❑The Locomotive workshop, which is a part of Northern Railway, was established by Oudh and
Rohilkhand Railway at Lucknow in the year 1868 for overhauling of Steam Locomotives.
❑In 1925,this workshop became part of East India Railways. Post-Independence-grouping of
Zonal Railways brought this workshop under Northern Railway.
❑ In its long journey in service of the nation ,it has excelled in adapting to latest technology and
has kept pace with changing requirements of motive power and rolling stock of Indian
Railways.
❑The workshop which was established primarily for maintenance of steam locomotives started
maintaining diesel locomotives from 1975, Electric locomotives from 1987, DEMU train sets
from 1996 and recently in June 2018 turned out first rake of MEMU train sets.
❑Workshop is headed by Chief Workshop Manager and is assisted by officers of Mechanical,
Electrical, Stores, Personnel & Finance departments.
3. CONTENTS
❑ Memu and Emu
❑ Railway Electrification System
❑ Pantograph
❑ Vacuum Circuit Breaker
❑ Relay
❑ AC EMU/MEMU POWER CIRCUIT
❑ Power Circuit Description
❑ Over Head Equipment
❑ Over Line Structure
❑ Safety Rules for OHE
❑ The OHE Layout Plan
❑ References
4. MEMU and EMU
❑ MEMU is Mainline Electric Multiple Unit is a commuter rail system in India
operated by the Indian Railway for semi-urban and rural areas. These trains are a
mainline version of the local EMU trains. MEMU train runs through AC overhead
line.
❑ The first MEMU Train was started on 17 October 1995, between Raipur and
Bilaspur.
❑ EMU is Electric Multiple Unit train consisting of self-propelled carriages
using electricity as the motive power designed for urban and semi-urban areas.
❑ The first EMU service was launched in 1925 from Victoria Terminus to Coorla
Harbour.
❑ These system requires no separate locomotive, as electric traction motors are
incorporated within one or a number of the carriages.
5.
6. RAILWAY ELECTRIFICATION SYSTEM
❑Railway electrification systems using alternating current (AC) at 25 kilovolts (kV) are used
worldwide, especially for high-speed rail. It is usually supplied at the standard utility
frequency (typically 50 or 60Hz), which simplifies traction substations.
❑ The development of 25 kV AC electrification is closely connected with that of successfully
using utility frequency .The development of 25 kV AC electrification is closely connected
with that of successfully using utility frequency..
❑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 a super capacitor.
❑Electric power for 25 kV AC electrification is usually taken directly from the three-
phase transmission system.
❑The system uses multiple electrical units operating on 25 kV AC drawn from overhead lines.
7. PANTOGRAPH
❑ A pantograph is an apparatus mounted on the
roof of an electric train, tram or electric bus to
collect power through contact with an overhead
line.
❑ Pantograph acts as mobile current carrying
equipment which is mounted on the roof. It
collects power from the overhead equipment
under both static and dynamic conditions and
transfers it to EMU.
❑ The whole assembly of pantograph is mounted
on the four foot insulators on roof. It is operated
for its raising/ lowering positions with
compressed air through servomotor.
❑ Ball bearings are provided for easy movement of
articulation at each joint. Flexible shunts are
provided to give continuous flow of current.
8. Components of a Pantograph
❑ Pantographs work as movable rods
to collect power from the overhead
wire. Compressed air from the
braking system controls the
movement of this mechanism.
❑ The simple functions of the
pantograph include:
•Provide continuous contact that
collects the electric current from
the overhead lines
•Transfer the electrical power from
the contact wire to the electric
generators or motors
9. VACUUM CIRCUIT BREAKER
❑ A breaker which used vacuum as an arc
extinction medium is called a vacuum circuit
breaker.
❑ In this circuit breaker, the fixed and moving
contact is enclosed in a permanently sealed
vacuum interrupter. The arc is extinct as the
contacts are separated in high vacuum.
❑ It is mainly used for medium voltage ranging
from 11 KV to 33 KV.
❑ It is the most important switching and protecting
equipment which connects & disconnects the 25
kV OHE power supply to the EMU through
pantograph.
❑ It is a single interrupter type vacuum circuit
breaker. Vacuum has excellent insulating
properties and therefore a small contact gap can
withstand high voltages.
10. Advantages
❑Vacuum circuit breaker does not require any additional filling of oil or gas. They do not need
periodic refilling.
❑Rapid recovery of high dielectric strength on current interruptions that only a half cycle or less
arcing occurs after proper contact separation.
Disadvantages
❑Requirements of high technology for production of vacuum interrupters.
❑It needs additional surge suppressors for the interruption of low magnetizing currents in a certain
range.
Applications
❑When the voltage is high and current to be interrupted is low these breakers have definite superiority
over the other breakers.
❑For low fault interrupting capacities the cost is low in comparison to other interrupting devices.
11. RELAY
❑ A relay is an electrically operated switch.
which sense the signal at abnormal condition
and send that signal to circuit breaker.
❑ Relays come in many varieties, the most
simple of which are DC and AC
versions. DC relays run off of the voltage
that comes out of a battery, which only flows
in one direction, and the DC stands for Direct
Current.
❑ AC relays will operate on Alternating
Current, which is what you have coming out
of the wall in your standard 120VAC
receptacle.
❑ The main operation of a relay comes in
places where only a low-power signal can be
used to control a circuit.
14. OVERHEAD EQUIPMENT
❑Overhead Equipment (OHE) in electric
traction system are used for transmitting
electrical energy to the electric locomotives,
trolley buses, trams and other electric traction
systems.
❑As an standard practice , an independent Mast
is used to support the OHE for each track to
obtain mechanical independence.
❑The type of conductor used is 25kV traction
consists of a stranded catenary from which
trolley-wire or contact wire is suspended by
means of droppers.
❑The OHE is supported by swiveling type
Cantilever bracket assembly. A tension of
1000 kgs is given in each conductor i.e.,
Catenary and Contact wire.
15. OVERINE STRUCTURE
❑All overhead electrical equipment, distribution
lines, transmission lines and feeders may be
collectively referred to as overhead lines.
❑Unlike uninsulated wires attached to cross
wires by clamps, a catenary system uses two
wires – catenary wire and a contact wire.
❑The catenary wire is hung between line
structures at specific tension and a contact
wire is attached to it at a frequent interval by
droppers.
❑Catenary wire material is made up of tiny
threads which feed electricity through to a
vehicle from the pantograph which presses
against the underside of the lowest overhead
wire- contact wire.
16. SAFETY RULES FOR OHE
❑The following rules are supplementary to the General and Subsidiary Rules and the
instructions.
❑Printed boards containing instructions regarding treatment of persons suffering from
electric shock should be exhibited in every OHE maintenance depot, equipment room,
switching station, cabin, OHE Inspection Car shed, loco shed, OHE Inspection Car
and wiring train and also in offices of SM, ASM, CYM, AYM and HTXR.
❑First Aid Boxes should be kept at every switching station, maintenance depot, in OHE
Inspection Car, breakdown vehicle and wiring train.
❑Ropes, come-along clamps, Trifor etc should be tested once in six months at least, in
the presence of an ATFO and record of such tests maintained in each depot.
17. THE OHE LAYOUT PLAN
❑These principles for preparation, checking and finalization of overhead equipment layout plans,
have been framed for standardization and guidance of Railways / Railway Electrification Projects.
❑ In some cases, the principles are obligatory and should be followed. In other cases, principles have
been evolved to standardize designs and to speed up the work.
❑The principles could be relaxed in special' cases, after studying individually the implications to
arrive at the best solution both from economical and technical points of view.
❑The “Principles of preparation and checking of OHE layout plans” first issued by erstwhile
Railway Electrification was revised by RDSO and issued as No. ETI/OHE /15 in July, 1983.
18. REFERENCES
❑Over Head Equipments A. K. RAWAL.
❑Indian Railways Year Book 2002-2003.
❑www.railway-technician.com
❑www.eng.ox.ac.uk
❑www.google.com
❑https://www.Wikipedia.org
