ELECTRIC TRACTION SYSTEM

PRESENTED BY:Anjal i

Neupane(BEL/070/203)Bishal Rimal (BEL/070/213)

CONTENTS INTRODUCTION MAJOR COMPONENTS REQUIREMENT OF AN IDEAL TRACTION SYSTEM OPERATION WHY ELECTRIC TRACTION SYSTEM?? LEADING TRACTION SYSTEMS AROUND THE WORLD PRESENT STATUS

ELECTRIC TRACTION SYSTEM

INTRODUCTION Driving forward of vehicle is called traction and the system, which

employs this type of mechanism is called Traction system.

Classified broadly into groups namely: Non-Electric traction system:

Traction system which do not involve the use of electricity such as steam engine drive, IC engine drive etc .

Electric traction system.The system which use electrical power for traction system i.e. for

railways, trams, trolleys, etc. is called electrical traction.

ELECTRICAL TRACTION SYSTEMElectric traction is meant for locomotion in which the driving

(tractive) force is obtained from electric motors(called as traction motors).

BACKGROUND

The first known electric locomotive was built in 1837 by chemist Robert Davidson of Scotland. It was powered by galvanic cells (batteries).

In 1880, Thomas Edison built a small electrical railway, using a dynamo as the motor and the rails as the current-carrying medium.

TYPES OF ELECTRIC TRACTION SYSTEM

POPULARLY PRACTISED VOLTAGE 25KV,50HZ

1500V &3000V DC

Multisystem: 1.5kv DC, 3kv DC , 1.5kv AC, 25kv AC

MAJOR COMPONENTS1-TRACTION SUBSTATION 2-OVERHEAD WIRING3-CURRENT COLLECTOR 4-TRACK5-TRACTION SYSTEM (VEHICLE)

MAJOR COMPONENTS CNTD…1-TRACTION SUBSTATION

Switchgear AC Circuit Breaker DC Circuit Breaker

Transformers & Rectifiers Transfer to required voltage level and Rectification.

Control and Monitoring unit Substation spacing

Typically 4km to 15km Depends on a number of factors including• Train loads

• Track grades• Losses• Over head wiring types

TRACTION SUBSTATION

2-OVERHEAD WIRING• Contact wire-suspended with minimum of sag so that contact between the trolley wire and current collector can be maintained at higher speeds.

• The wire is supported by another wire called as catenary.

• Two different types of catenary construction can be used-

single catenary:One or two contact wires supported by a

catenary wire compound catenary

A main catenary supports an auxiliary catenary, which in turn supports the contact wire.

MAJOR COMPONENTS CNTD…

Trolley collectorBOW COLLECTOR

PANTOGRAPH COLLECTOR

3-CURRENT COLLECTOR

MAJOR COMPONENTS CNTD…

4-TRACK

5-TRACTION SYSTEM ( VEHICLE) CIRCUIT BREAKERS: To disconnect the engine

(motor) in case of some fault

TRANSFORMER: Tap changing transformer is installed in the locomotive for stepping down the voltage according to the requirement of the traction motor.

ON LOAD TAP CHANGER: Used for varying the output voltage for controlling the speed of motor.

RECTIFIER AND SMOOTH REACTORS: Semiconductor rectifier are used for AC to DC power conversion. Smooth reactors eliminates ripples found on output side of rectifier.

MAJOR COMPONENTS CNTD…

TRACTION SYSTEM ( VEHICLE) CNTD…..TRACTION MOTORS:

D.C series motors:

Single phase A.C series motors:

Easier construction

Three-phase Induction motors

High torque at low speeds & low torque at high speeds.

Easy speed control

Speed of an ac series motor may be controlled efficiently by taps on a transformer

Robust construction Trouble free operation Less maintenance requirement complicated speed control systems Not suitable for traction work Automatic regeneration is the main advantage of this motor

CONTROL UNIT: REMOTE CONTROL CENTER(RCC):

From substation/ Traffic control division Nerves system for traction system. 3 Pair of conductors from and to RCC

TRACTION SYSTEM ( VEHICLE) CNTD…..

SYSTEM CONTROL CENTER: Master controller ,From the

vehicle Enable output from the vehicle

operator’s commands Forward, reverse, powering,

neutral and braking, to the electric control device

REQUIREMENT OF IDEAL TRACTION SYSTEM

The wear caused on the track should be minimum. Maximum traction efforts should be exertion at starting in order to

have rapid acceleration. Capacity of withstanding voltage fluctuation and temporary

interruption of supply. Braking should be possible without excessive wear on the brush. Parallel running usually more than one motor (two or four) should be

possible.

OPERATION OF TRACTION SYSTEM

[1] Traction transformer[3] Traction control[5] Traction motor[7] Auxiliary converter[9] Energy storage

[2] Traction convertor[4] Control and Monitoring System[6] Diesel engine generator[8] Battery charger

BRAKING OF ELECTRIC TRACTION MOTORBRAKING CAN BE ACHIEVED BY TWO METHODS-

1.MECHANICAL BRAKING2.ELECTRICAL BRAKING

ELECTRICAL BRAKING very superior then MECHANICAL BRAKINGELECTRICAL BRAKING

CLASSIFIED INTO THREE CATEGORIES-1.PLUGGING2.RHEOSTATIC BRAKING3.REGENERATION

1.PLUGGING- Plugging is applied by changing phase sequence of synchronous or induction motors.2.RHEOSTATIC BRAKING- Connection are made changed from power configuration to brake configuration and resistor are inserted in motor circuit.3.REGENERATIVE BRAKING- Motors become generators and feed resulting current back into supply system.. Return current, generated during braking, to the supply system for use by other trains

WHY ELECTRIC TRACTION SYSTEM???Cheapness : Low operation costCleanliness: Smoke and gas freeMaintenance cost : 50% less then other steam enginesStarting time and speed: Without loss of time.High starting torque : Uses of D.C & A.C series motor- very high

starting torque.Braking : Regenerative breaking is used which

feeds back energy.Saving in high grade coal :Saving of non-renewable energy source.

LEADING TRACTION SYSTEMS AROUND THE WORLD

Magnetic traction (maglev). Speeds up to 581 kmph have been

successfully tested. Shinkansen (bullet train) uses electrical

system, offering high acceleration and deceleration.

It employs an automatic train control system (atc),which controls all train movements ,track ,station and schedule are networked and computerized.

Software Analysis and Modelling (etrax)

LONGEST ELECTRIC TRACTION SYSTEM IN RUSSIA

OUR NEIGHBOURS CHINA AND INDIA ARE IN 3RD &4 TH POSITION.

Don’t we bear the potential??Yes, of course!!!!!

PRESENT STATUS

Past electric trolly bus

Present status of electric trolly bus

Started in 1975 - gift by the government of the People's Republic of China. 

13km - 10,000 passengers dailyRoute: Tripureshwor Ktm – Suryabinayak Bhaktapur

Tripureshwor – Koteshwor

NEPAL

Suspended in 2008Permanently dismissed in 2009 by KMC due to chronic unprofitability.

MAY 13, 2016 STARTED

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