PROJECT REPORT ONVOCATIONAL TRAINING

IN INDIAN RAILWAY

ACKNOWLEDGMENT

I am very much thankful to the concerning officers and staff of INDIAN RAILWAY AGRA CANTT for their valuable guidance and advice, especially to Mr. Pradeep chhabra without their help I would never have completed my training. I am also thankful to Sr. Divisional Electrical Engineer North Central Railways for allowing me for this training.

INTRODUCTION

Indian Railway is the world’s fourth largest commercial, by number of employees with over million employees. Railways were first introduced in India in 1853. Indian Railways operates both long distance and suburban rail system on a multi-gauge network of board meter and narrow gauges.

Form 20th Dec 2010, the railways had developed a 5 digit numbering system. This need is required because IR RUNS 10,000 trains daily

AGRA CANTT SUBSTATION

The 2 x 25KV autotransformer system may be used on 25 kv lines to reduce energy losses. It should not be confused with the 50 kv system. The voltage between the overhead line(3) and the feeder line (5) is 50 kv but the voltage between the overhead line (3) and the running rails (4) remains at 25 kv and this is the voltage supplied to the train. This system is used by Indian Railways

FEEDER The feeders that receives the power form CESC, and

the power is step down with the help of step down transformer and then supplied to various colonies, piller box, etc. This process is shown with the help of above connection diagram .

6kv from CESC goes to HT ocb 400A with the hwlp of HT busbar 400A is divided into two 200A and sent to two transformer each of 250 kva then sent to various parts.

OIL TYPE TRANSFORMERTransformer oil or insulating oil is usually a highly-refined mineral oil that is stable at high temp and has excellent electrical insulating properties. It is used in oil-filled transformers, circuit breakers. Its function are to Insulate, suppress corona and arcing, and to serve as a coolant.

The oil helps cool the transformer because it also provides part if the electrical insulation between internal live parts, transformer oil must remain stable at high temp for an external radiation through which the oil circulates by natural convection.

The flash point(min) and pour point(max) are 140 c to -6 c respectively. The dielectric strength of new untreated oil is MV/m (RMS)and after treatment it should be>24 MV/m (RMS)

Testing and oil quality

Transformer oils are subjects to electrical and mechanical stresses while a transformer is in operation. In addition there is contamination caused by chemical interaction with windings and other solid insulation, catalysed by high operating temp. As a result the original chemical properties of transformer oil change gradually, rendering it ineffective for its intended purpose after many years. Hence this oil has to be periodically tested to ascertain its basic electrical properties,These tests can be divided into 1. Dissolved gas analysis2. Furan analysis3. PCB analysis4. General electrical and physical tests:-

colour and appearanceBreakdown VoltageWater content

TRACTION

In Overhead Electrification System, the supply of electricity is through anoverhead system of suspended cables known as the catenary.

The loco uses a Pantograph, to make contact with the overheat contactcable and draw electricity from it to power its motors.

The return path for the electricity is through the body of the loco and the wheels to the tracks, which are electrically grounded.

Conductivity may be reduced in cases of dirt and debris on the rails.

There are 2 types of Electrification system in Indian railways-

DC System: In DC system with overhead catenary, the basic principle is the same, with the catenary being supplied electricity at 1.5kv DC. The current from the catenary goes directly to the motor OR convert the DC supply to AC internally using inverters or a motor-generator combination which then drives AC motors.

Single system(AC): The overhead catenary is fed electricity at 25kv AC(single-phase) from feeding posts which are positioned at frequent intervals alongside the track.

A Remote Control Centre, has facilities for controlling the power supply to different sections of the catenaries fed by several substations in the area.

VOLTAGE USED FOR ELECTRIC TRACTION IN INDIA

Voltages used are 1.5kv DC and 25kv AC for mainline trains.

The 1.5kv DC overhead system is used around Bombay.

The Calcutta metro uses 750V DC traction with a third-rail mechanism for delivering the electricity to the EMUs.

The Calcutta trams use 55V DC with an overhead catenary system with underground return conductors.

Delhi metro uses 25KV AC overhead traction.

NO LOAD TESTING SCHEDULE OF A ASSEMBLED TRACTION MOTOR

The motor is run at 1500 rpm, if running is smooth the motor is run for 30 min.

The rotation of the motor is changed and run at 1500 rpm for another 30 min. Steady state temp rise, should motor exceed 35 degree centi.

The speed is increased to 2000 rpm and run up to 15 min.

The speed is increased to about 2725 rpm.

Temp rise in the zone should not exceed 50 to 60 degree centi.

APPARATUS USED

PANTOGRAPH

MAIN TRANSFORMER

RECTIFIER

REVERSER

CLR

WINDING CHANGE-OVER SWITCH

BATTERY & BATTERY CHARGER

PROTECTION CIRCUIT AND RELAY

SWITCH GROUP 1& 2

PANTOGRAPH CURRENTTRANSFORMER

MAINTRANSFORMER

TAPCHANGER

RECTIFIERSMOOTHINGREACTOR

ADDITIONALSMOOTHING

REACTORREVERSER MOTOR

BLOCK DIAGRAM

DISC JUNCTION

TRACTIVE EFFORT DISTRIBUTION IN E.M.U.