05-09-2014, 11:54 AM
MAGLEV TRAINS
MAGLEV TRAIN.pptx (Size: 389.18 KB / Downloads: 28)
introduction
Out of science fiction books, a train running on magnetic and electrical force only, no wheels, no engine and the steel track replaced by a guideway, the maglev (Magnetic Levitation) trains are becoming a reality more then ever. With a record of 581 km/h, these trains open new visions about future transportation.
Just like airplanes revolutionize 20th century’s transportation, maglev trains are expected to do the same thing with 21th century’s transportation.
What is magnetic levitation:
It is a method of propulsion that uses magnetic levitation to propel vehicles with magnets rather than with wheels ,axles and bearings. With maglev, a vehicle is levitated a short distance away from a guide way using magnets to create both lift and thrust. High-speed maglev trains promise dramatic improvements for human travel if widespread adoption occurs.
How does it work?propulsion
Electromagnetic Propulsion:
In real life the opposite poles of magnets attract each other and like ends repel, this is the simple principle behind electromagnetic propulsion.
However electromagnets attract metal objects while charged with electricity, the pull is temporary and dependent on the charge.
For a train to operate three major components must be present in the system: a powerful electrical power source, large guidance magnets attached to the underside of the train, a track lined with metal coils.
Suspension
There is 2 forms of suspension technology:
1-Electromagnetic suspension
2-Electrodynamic suspension
1-Electromagnetic suspension:
In current EMS systems, the train levitates above a steel rail while electomagnets attached to the train, are oriented toward the rail from below.
The electromagnets use feedback control to maintain a train at a constant distance from a track.
Development of the concept
A U.S. patent, dated 1 October 1907, is for a linear motor propelled train in which the motor, below the steel track, carried some but not all of the weight of the train. The inventor was Alfred Zehden.
The world's first commercial automated system was a low-speed maglev shuttle that ran from the airport terminal of Birmingham International Airport (UK) to the nearby Birmingham International railway station from 1984 to 1995.
Present using
Shanghai Maglev Train:
Contracted from 2000-2004 with a cost of 1.2 billion $, it links the Pudong Airport and Shanghai Metro, it is based on the maglev technologies of Siemens. It caries about 7000 passengers per day