SOUTH CENTRAL RAILWAY: ELECTRIFICATION

The Electrical Department

The Electrical Department of South Central Railway is the busiest and most important department of the SCR System. Headed by Chief Electrical Engineer, the Electrical Department is responsible for the management, maintenance and operation of:

A large fleet of Electric Locomotives of five different types, housed in the loco sheds at Vijayawada and Lallaguda

Self-generating type Train lighting & Air Conditioning systems on the coaches

Overhead equipment and power supply installations of Electric traction

General electric installations in Railway stations, yards, offices, colonies, workshops, loco sheds etc.

Main line EMU coaches.

EMU coaches

GENERAL SERVICES & LIGHTING

Activities

Power supply arrangements to Railway installations and Work Shops

Maintenance and operation of pumping installations

Maintenance and operation of electrical installations such as Water coolers, AC plants, Lifts etc.

Maintenance of lights, fans and AC system in passenger coaches, including power supply systems for the same

Construction activities in this area

Monitoring of energy conservation measures in these areas

Achievements

678 stations are electrified with local power supply.
339 water coolers have been provided at 158 Railway stations
Escalators are provided at Vijayawada Railway Station which provide easy movement for passengers at this station which deals with the largest number of trains on SCR

Various measures are being undertaken for effective energy conservation. They include the use of energy efficient lamps, segregation of essential & non-essential loads at stations, provision of Electronic Ballasts, electrification of Railway stations and gate lodges using non- conventional sources of energy etc.
All the 2,860 passenger coaches of SCR have been converted to 110 V working system from 24 V working system, for better illumination and reliability.
The required power in the coaches is self-generated by means of axle driven bogie mounted brushless alternator of 4.5KW capacity that generates power when the train is in motion. The generated power is rectified and regulated, fed to fans and lights, and stored in batteries. The maintenance yards have been provided with pole mounted battery chargers so as to charge cells when the coaches are maintained at terminal stations.
A total of 285 AC coaches of various classes are being maintained with 10 / 14 tons of Air Conditioning Systems, for which power is self-generated when coaches are in motion.

Work Shops: The electrical assets of the coaches are periodically overhauled during the servicing of coaches at Work Shops in Lallaguda, Tirupati.

ELECTRIC LOCOMOTIVES

Activities

Maintenance and operation of Electric locomotives used for hauling passenger / goods trains

Maintenance and operation of Mainline Electrical Multiple Units (MEMUs)

Maintenance and operation of Electrical Multiple Units (EMUs) for Multi-Modal Transport System (MMTS).

Construction activities pertaining to this section like setting up of new Sheds, POH facilities etc.

Achievements

A total of 286 electric locomotives consisting of five types of locomotives are housed at Lallaguda and Vijayawada loco sheds. A Third Electric loco shed at Kazipet is under construction. The Electric loco sheds carry out preventive maintenance in the form of periodical maintenance schedules / overhauls and scheduled repairs on these electric locomotives.
Mainline Electrical Multiple Units, each comprising 3 Motor coaches and 9 Trailer coaches are deployed in Guntur, Tenali, Vijayawada - Rajahmundry - Kakinada and Visakhapatnam on Vijayawada division. The service is introduced between Hyderabad, Kazipet and Vijaywada of Secunderabad division. One rake of 2 motors coaches and 6 trailer coaches is deployed on Visakhapatnam - Palasa section.

Electrical Multiple Units, each comprising 2 Motor coaches and 6 Trailer coaches are deployed in Falaknuma, Hyderabad and Lingampally sections for MMTS service.
A separate Traction Rolling Stock Operations ( TRO ) organisation at divisional level for the operation of the electric locomotives and MEMUs on the three electrified divisions of SCR. TRO looks after the availability, fitness and technical updating of the running staff as well as minor servicing of locomotives.

TRACTION DISTRIBUTION

Activities

Maintenance of traction power supply installations
Maintenance of traction overhead equipment
Supervisory Remote Control System
Construction activities pertaining to this section
Monitoring of energy conservation in Electric Traction

Progress of Electrification on South Central Railway

Electrification on SCR started with the electrification of Vijayawada - Gudur section in 1980. By the end of December 2003 a total of 1,620 route kms and 3,910 track kms have been electrified, spreading over five divisions Secunderabad,Hyderabad, Vijayawada, Guntur and Guntakal of SCR. Out of the total 5,752 route kilometers of track on SCR, 1,620 route kilometres i.e., 28% of the total track have been electrified .

Electrified sections:

Vijayawada - Gudur
Vijayawada - Guntur - Nallapadu
Vijayawada - Kazipet - Ballarshah
Visakhapatnam - Vijayawada
Gudur - Renigunta - Tirupati - Pakala - Chittoor - Katpadi
Kazipet - Secunderabad - Hyderabad - Sanathnagar
Guntur - Tenali
Samalkot - Kakinada Port
Motumarri - Jaggayapeta
Dornakal - Karepalli - Singareni collieries
Manikgarh - Gadchandur
Sanathnagar - Lingampalli Under Multi Modal Transport
Secunderabad - Falaknuma System of twin cities

Electrified Divisions

Division	Total route Km. electrified	Total track Km. electrified
Secunderabad	793	1839
Vijayawada	660	1734
Guntakal	94	190
Guntur	57	108
Hyderabad	16	39
TOTAL :	1620	3910

System of working of Electric Traction :

The Electric supply from the State Grid is availed at 220/132 KV, 2 Phase and is stepped down to 25 KV, Single Phase at the Traction sub-stations. This 25 KV single phase supply is fed to the over head conductor system consisting of a grooved contact wire suspended from catenary wire by flexible droppers. There is a continuous sliding contact between the pantograph pan of the locomotive and the bottom of the contact wire. The pantograph of the locomotive when raised applies a pressure of 7.0 Kg/Cm-square against the contact wire which ensures the continuous and smooth collection of current from the Over Head Conductor to the locomotive. The 25 KV supply is further stepped down and rectified and fed to the Traction Motors. The return current flows through the loco wheels to the Rails and form the Rails to the earthed terminal of the traction transformer thus completing the single phase electric circuit. As the rails are earthed, it is ensured that the potential of the return current, is not increased above the earth potential. This ensures that there is no electric hazard to the public coming in contact with electrified tracks. The speed variation of the locomotive is achieved by varying the input voltage to the traction motors.

Technological Improvements

In the newly electrified sections, 21.6/30.24 MVA Power Transformers have been provided at Traction Sub-stations (TSS). The capacity of these transformers can be increased from 21.6 MVA to 30.24 MVA by switching on forced air circulation fans.
The switch gear at the TSSs is of state-of-art SF6 vaccum type. These switch gears require less maintenance as compared to oil switch gears, which were in use so far.

Provision of improved version of distance protection relays at TSSs to avoid spurious circuit breaker trippings and consequent interruptions to OHE power supply.
Provision of insulated copper cadmium catenary wire under Foot Over Bridges/ Road Over Bridges to avoid power supply interruptions to OHE on account of bird/ monkey menace.
Provision of PTFE type short neutral sections in OHE to avoid stalling of Goods trains in gradient section.
The manually operated isolators at major yards have been motorized to facilitate quick isolation of faulty section of OHE and to reduce the detention to trains to main lines during breakdowns/ unusual occurences.
Contactless Remote Sensing Device is used for identifying hot spots pertaining to connectors of the OHE jumpers, Busbars etc., of the TSSs/ Switching stations and to pan attention prior to failure.
Provision of long creepage Insulators for the OHE situated in polluted zone to avoid flash over and consequent failure of insulators.
Provision of Hybrid Insulators where OHE is prone for stone pelting activity by miscreants/cow-boys.
Provision of High speed Auto reclosures to all feeder circuit breakers to minimise power supply interuption to OHE.
Provision of static type relays in place of electromagnetic type relays.

Special Features of SCADA:

	PC based computer remote control system with the following special features have been installed at Secunderabad and Vijayawada All operations of Circuit Breakers, Interruptors etc., situated in the Sub-stations and Switching Stations over the length of Railway line can be remotely operated from the Divisional Control Office by simple commands through key board/mouse

The status of different equipment and values of voltages and currents are continuously monitored and displayed on the video monitors attached to the operator workstations.
Automatic fault isolation is done by SCADA system in case of faults on OHE
All the operations of the TPC and events are automatically logged in the system
SAFETY
- All the traction masts and structures are earthed properly so as to negate any possibility of electric shock due to any leakage of power. Sufficient clearances are maintained with earthed structures. A working clearance of two metres is maintained from the live OHE.
- As the power supply to Electric locomotive is remotely controlled from the Divisional Control Office, when the train is running out of control, the train can be brought to a stop by switching off the supply to OHE. Similarly when there is a derailment on one line in a double line section, which is noted by disruption to traction power supply, the supply to the adjoining line is switched off to avoid the collision of the running train with the derailed trains.
Some of the Safety Tips to be followed by "PUBLIC" to Safely travel in Electrified section :
- Donot carry vertically long ploes/ any other articles in the vicinty of overhead live conductors.