The document discusses the principles and operation of maglev trains. It begins by providing a brief history of steam locomotives and their increasing speeds over time. Maglev trains levitate above tracks using magnetic fields and have no contact with the tracks. There are two main types - electromagnetic suspension (EMS) which uses attractive forces, and electrodynamic suspension (EDS) which uses repulsive forces between magnets on the train and guideway. Propulsion is provided by linear induction motors or synchronous motors that accelerate the train. Lateral guidance is achieved through the shape and positioning of levitation magnets and rails. Key advantages of maglev trains include very high speeds, low noise, minimal pollution and energy use.

1. PRESENTED BY
Soumyabrata Basak

2. INTRODUCTION
• When English inventor Richard Trevithick introduced the steam
locomotive on 21 February 1804 in Wales, it achieved a speed of
8 km/h (5 mph). In 1815, Englishman George Stephenson built
the world's first workable steam locomotive. In 1825, he
introduced the first passenger train, which steamed along at 25
km/h (16 mph). Today, trains can fly down the tracks at 500 km/h
(311 mph). And fly they do, not touching the tracks.
• 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 581km/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.

3. • . Magnetic levitation is the use of magnetic fields to levitate
a (usually) metallic object.
• Manipulating magnetic fields and controlling their forces
can levitate an object.
• Using either Ferromagnetism or Diamagnetisim object can
be levitated.
• A superconductor is perfectly diamagnetic and
electromagnets can exhibit varying levels of
ferromagnetism
Maglev –Magnetic Levitation

4. Maglev trains have to perform the following functions to operate in high
speeds
1.Levitation
2.Propulsion
3.Lateral Guidance
Basic Principle of Maglev Trains
Types of Maglev Trains
Based on the technique used for Levitation the are two types of Maglev
trains
1. Electromagnetic Suspension -Attractive
2. Electrodynamic Suspension -repulsive

5. • In the EMS-attractive system, the electromagnets which do
the work of levitation are attached on the top side of a casing
that extends below and then curves back up to the rail that is
in the center of the track.
 The rail, which is in the shape of an inverted T, is a
ferromagnetic rail.
 When a current is passed through it, and the electromagnet
switched on, there is attraction, and the levitation
electromagnets, which are below the rail, raise up to meet the
rail. The car levitates.
Principle of Magnetic Levitation

6.  A linear electric motor (LEM) is a mechanism which converts
electrical energy directly into linear motion without employing
any intervening rotary components.Linear Induction Motor
(LIM) is basically a rotating squirrel cage induction motor
opened out flat.Instead of producing rotary torque from a
cylindrical machine it produces linear force from a flat one.
. Speeds vary from zero to many meters per second and are
determined by design and supply frequency
• A conventional rotary synchronous motor , is made up of two
rings of alternating north and south magnetic poles. The
outer ring (the stator) is stationary, while the inner one (the
rotor) is free to rotate about a shaft. The polarity of the
magnets on one (either) of these rings is fixed; this element is
known as the field.
• The magnets of the other ring, the armature, change their
polarity in response to an applied alternating current.
• Attractive forces between unlike magnetic poles pull each
element of the rotor toward the corresponding element of
the stator.
• Just as the two poles are coming into alignment, the polarity
of the armature magnets is reversed, resulting in a repulsive
force that keeps the motor turning in the same direction.
• The armature poles are then reversed again, and the motor
turns at a constant speed in synchronism with the alternating
current which causes the change in polarity
Principle of Propulsion

7. Principle of Lateral Guidance
The levitation magnets and rail are both
U shaped(with rail being an inverted U).
The mouths of U face one another.
This configuration ensures that when ever a levitational
force is exerted, a lateral guidance force occurs as well.
If the electromagnet starts to shift laterally from the center
of the rail, the lateral guidance force is exerted in
proportion to the extent of the shift, bringing the
electromagnet back into alignment.

8. Electrodynamic Suspension
• PRINCIPLE OF MAGNET LEVITATION
Electrodynamic Suspension uses Superconductors for levitation,propulsion
and lateral guidance.
•The passing of the superconducting magnets by figure eight levitation coils
on the side of the tract induces a current in the coils and creates a magnetic
field. This pushes the train upward so that it can levitate 10 cm above the
track.
•The train does not levitate until it reaches 50 mph, so it is equipped with
retractable wheels.

9.  In Electrodynamic suspension (EDS), both the rail and the train exert a magnetic field,
and the train is levitated by the repulsive force between these magnetic fields. The
magnetic field in the train is produced by either electromagnets or by an array of
permanent magnets . At slow speeds, the force is not large enough to support the
weight of the train. For this reason the train must have wheels or some other form of
landing gear to support the train until it reaches a speed that can sustain levitation.
• The propulsion coils located on the sidewalls on both sides of the guideway are
energized by a three-phase alternating current from a substation, creating a shifting
magnetic field on the guideway.
• The on-board superconducting magnets are attracted and pushed by the shifting field,
propelling the Maglev vehicle.Braking is accomplished by sending an alternating
current in the reverse direction so that it is slowed by attractive and repulsive forces.
PRINCIPLE OF PROPULSION

10. PRINCIPLE OF LATERAL GUIDANCE
• When one side of the train nears the side of the guideway, the
super conducting magnet on the train induces a repulsive
force from the levitation coils on the side closer to the train
and an attractive force from the coils on the farther side.
• This keeps the train in the center.
•

11. 1. Due to the lack of physical contact between the track and the vehicle, there is
no rolling friction, leaving only air resistance.
2. Maglevs can handle high volumes of passengers per hour and do it without
introducing air pollution along the right way.
3. Safest way of transportation, since its all automatically controlled, no chance
of collision or brake down.
4. No burning of fossil fuel, so no pollution, and the electricity needed will be
nuclear or solar.
5. Maglev uses 30% less energy than a high-speed train traveling at the same
speed (1/3 more power for the same amount of energy).
6. The operating costs of a maglev system are approximately half that of
conventional long-distance railroads.
7. Research has shown that the maglev is about 20 times safer than airplanes,
250 times safer than conventional railroads, and 700 times safer than
automobile travel.
8. Maglev vehicle carries no fuel to increase fire hazard
9. The materials used to construct maglev vehicles are non-combustible, poor
penetration transmitters of heat, and able to withstand fire.
Advantages of Magnetic Levitated
Transportation System

12. Disadvantages of Magnetic Levitated
Transportation System
• The powerful magnets demand a large amount of electricity
to function so the train levitates. What makes the maglev
trains much more expensive to build and to operate.
 The weight of the large electromagnets in EMS and EDS
designs are a major design issue. A very strong magnetic field
is required to levitate a massive train.
 Due to its high speed and shape, the noise generated by a
maglev train is similar to a jet aircraft, and is considerably
more disturbing than standard train noise. A study found the
difference between disturbance levels of maglev and
traditional trains to be 5dB (about 78% noisier)
 Very costly to operate since it needs large magnets and a very
advanced technology and huge amount of electrical power.

13. Conclusion
• The MagLev Train: Research on this ‘dream train' has been going on for the
last 30 odd years in various parts of the world.
• Maintenance costs decrease
• The MagLev offers a cheap, efficient alternative to the current rail system.
A country like India could benefit very much if this were implemented
here. Further possible applications need to be explored
• It’s no longer science fiction, maglev trains are the new way of
transportation in the near future, just some obstacles are in the way, but
with some researches nothing is impossible.
• With no engine, no wheels, no pollution, new source of energy, floating on
air, the concept has token tens of years to develop, just recently it’s true
capacities has been realized.
• Competing planes with speed, boats with efficiency, traditional trains with
safety, and cars with comfort, it seems like it isn't a fair fight...

14. • http://www.21stcenturysciencetech.com/articles/Summer03/
maglev2.html
• http://en.wikipedia.org/wiki/Magnetic_levitation_train
• http://science.howstuffworks.com/maglev-train.htm
• http://future.wikia.com/wiki/Maglev_train
• http://www.geocities.com/nastywik/trains.html
THANK YOU
References

15. Principle of Propulsion