electric traction system and motors used in electric traction system
TRANSCRIPT
ELECTRIC TRACTION SYSTEM
Presented by:
M.ibrar younas
ContentsElectric traction.
History of electric traction.
Advantages and Disadvantages
Motors used in electric traction.
Advantages of AC system over DC
HISTORY OF ELECTRIC TRACTIONThe years 1881 saw the birth of the first
electric railway run by German Engineer Werner Van Siemens.
Electric traction was introduced on indian railways in years 1925 on 1.5 KV DC
In the years of 1957,indian railway decide to adopt 25KV,50HZ AC traction based on French(SNCF) technology.
WHAT IS ELECTRIC TRACTION
Electric traction is meant for locomotion in which the driving force is obtained from electric motors.
It involves to utilization of electric power for traction system.
ADVANTAGESo High starting torque
o Lower running cost of locomotive & multiple units
o Less noise pollution
o Breaking system is very efficient & simple
DISADVANTAGES.Problem of supply failure
High capital cost
Electrically operated vehicles have to move on guided track only
Motors Used In Electric Traction
Three motors used in electric traction.
D.C series motors.
Single phase A.C series motors.
Three phase induction motors.
D.C SERIES MOTOR.D.C series motor develops high torque at low
speed and low torque at high speed , exact requirement of the traction units.
D.C series motor torque is independent of the line voltages.
D.C series motor unaffected by the variations in the line voltages/
CIRCUIT DIAGRAM & CHARACTIRISTIC CURVE
SINGLE PHASE A.C SERIES MOTOR
CIRCUIT DIAGRAM
CHARACTERISTIC CURVE
3-PHASE INDUCTION MOTORHaving constant speed
Constant torque speed characteristics
Low maintenance cost
High efficiency
Circuit Diagram
Characteristic curve
Advantage of AC motor over DCDc motor use commotators which are prone
to failure because of vibration and shock
It is hard to use dc motor for regenerative breaking
It use extra switch gear therefore system is bulkier
Ac motor have simple construction