Magnetic Levitation

1. K r i s h n a d i t y a R a n a
( I T - 4 9 )
Y a t i n D e s a i ( E C - 0 2 )
K i s h a n P a t e l ( E C -
0 3 )
Electromagnets and
superconducting magnets
have allowed us to create a
magnetic levitating train
nicknamed “Maglev” that
floats on the track.
Magnetic
Levitation

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What is MAGNETIC
LEVITATION?
Magnetic levitation, maglev,
or magnetic suspension is a method by
which an object is suspended with no
support other than magnetic
fields. Magnetic force is used to
counteract the effects of
the gravitational and any other
accelerations.
The two primary issues involved in
magnetic levitation are lifting force:
providing an upward force sufficient to
counteract gravity, and stability:

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insuring that the system does not
spontaneously

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slide or flip into a configuration where
the lift is neutralized.
Magnetic levitation is used for maglev
trains, contactless melting, magnetic
bearings and for product display
purposes.
Maglev’s Levitation is basically baed on
two simple and fundamental laws of
electromagnetic.
 FARADAY’S LAW
 LENZ’S LAW

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FARADY’s LAW:
It states that:
"The emf (electromagnetic force)
induced in a circuit is directly
proportional to the time rate of change
of magnetic flux through the circuit." is
the electromagnetic force (EMF) in volts
FB is the magnetic flux through the
circuit (in Webers).
Faraday’s law simply says that, if a
closed loop of wire is placed close to a

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permanent magnet, then electric
current can be induced into the wire by
moving either the magnet with respect
to the coil or vice versa.
Hence it is the relative movement
between the coil and the magnet that
matters (change in flux cutting the
loop).
When the magnet is moved toward the
loop, the current induced flows in one
direction, but when it is moved away, it
flows in opposite direction, it indicates
that the direction of the current
depends on the time rate of change of
the field, i.e. if the field is getting
stronger or weaker as time progresses.

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The direction of induced current is
further explained by Lenz’s law.
LENZ’S LAW
LENZ’S law describes about the direction
of current being induced by magnetic
field as described in faraday’s law.
It states that:
“Induced electromotive force generates
a current, which flows in such direction
as to induce a counter magnetic field
that opposes the magnetic field
generating the current”

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The induced EMF creates a current that
itself creates a secondary magnetic field.
This secondary magnetic field also
changes with time and thus creates a
changing secondary magnetic flux. The
secondary flux changes in such a way to
oppose the change in flux creating the
EMF.
To further understand, consider a coil
and permanent magnet as shown in
figure. No change in flux means no
current induced. Now consider when the
north pole of a permanent magnet is
pushed into a loop the flux increases. An
upwards secondary magnetic field is
created that opposes the downward B-

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field of the magnet, and thus the current
in loop must flow counterclockwise in
order to create this secondary B-field.
When the magnet is removed from the
loop , the decreasing B-field in the loop
creates a decreasing flux. To oppose this
decrease, the current in the loop flows in
such a way that tries to sustain the
magnetic field. The current now has to
flow clockwise in order to create a
positive secondary flux that tries to
counter acts the decreasing flux due to
the with drawl of the permanent
magnet.

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Maglev Train
Maglev trains are trains that levitate
about 10 mm off the tracks using
repulsive electromagnets on both the
tracks and the train itself. This levitation
greatly reduces friction, potentially
allowing the train to move faster and
consume less power than it would
otherwise. There are no regularly used
maglev trains, though test tracks have
been built in Germany, the USA, and
Japan; including the MLX01, located in

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Japan, which is the fastest train ever
built at 550km/h (344 mph).
History Of Maglev
Trains
The history of maglev train started
already in the beginning of the 1900's
century, when the American Robert
Goddard and the French Emile Bachelet
conceived the idea of frictionless trains.
The scientists did not succeed with their
idea, so the concept of frictionless
trains lay dormant for about 60 years
until the Japanese and the German
started to do research on the subject.

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The Japanese started their research on
maglev transportations in the
beginning of the 1970s. After many
years of experiments the Japanese
constructed their first test line, 7 km in
1975, and finished it in 1977. Many test
runs started in July 1977 with a velocity
of 517km/h. In 1990 Japan constructed
the Yamanashi Maglev test line. This
test line became 42.8km long and the
first running test was in 1997. The
Japanese prototype of maglev train is
using repulsive forces to levitate the
train, known as electrodynamic
suspension, EDS.
The German also started research on
maglev train in early 1970s. It took

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them ten years to complete the
construction of the first track model. In
1993 the longest nonstop test running
was 1.674 km. That same year the
speed record was 450 km/h. In China,
2003, they finished a 30 km long
German variant of maglev train in
Shanghai, that propels by attractive
forces, electromagnetic suspension,
EMS . This is the first commercial
magnetic levitation train in the world.
This project cost over 1 billion dollar.

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Advantages :
 Maglev train cars are less expensive
to build and are relatively quiet in
comparison to conventional trains.
 The maglev tracks take up a lot less
land, because they are elevated. This
also reduces the amount of
collisions and accidents.
 No traffic!.
 Maglev trains use far less energy
than other types of transportation.

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 Maglev trains do not pollute (since
instead of using fossil fuels,
magnetic fields are used to levitate
and propel the trains
forward).Maglev trains are much
faster, because they float over the
track eliminating rolling resistance
and potentially improving the power
efficiency.
 Maglev trains require Less
maintenance (no wear because they
float over the track).
 A lot of potential. The possibility of
linking 2 cities, over a distance of
1500km.

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Disadvantages :
 Cost is major issue when considering
maglev trains, especially since they
cannot operate on the existing,
conventional rails.
 Guideways would need to be built in
order to make use of this new
technology, costing approximately
$8.5 billions.

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 The weight of the electromagnets in
the EMS and EDS systems are also
an issue.
 A very strong magnetic field is
required to levitate the heavy trains,
(the transrapid TRO7 weighs 45
tons) and maintaining the field
constant requires a lot of energy
which is expensive.

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Current scenario with
maglev trains.
Japan’s new maglev train will be the
world’s fastest subway: Japan is
unveiling a train that travels even faster
than a speeding bullet train. This week,
the Central Japan Railway Company is
havingpassengers test out a maglev
train that reaches speeds of up to 500
kmh (about 311 mph). The train will run
between Tokyo and the central city of
Nagoya by 2027, cutting traveling time
from 90 minutes to 40 minutes.
MAGLEV TRAIN , a new age for japan’s
ECONOMY.

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A traditional leader in the export of
high speed rail technology, Japan faces
stiff competition from its regional
archrival China, which has been
aggressively building high speed within
the country as well as trying to sell it
elsewhere. The world’s fastest
passenger train is currently Shanghai’s
maglev, which travels to and from
Pudong International Airport at about
431 kmh.
Moreover, Japan’s maglev speeds may
soon be overtaken by Chinese
engineers. Researchers from a Chinese
university have built a prototype for a
“super maglev” that operates within a
vacuum tube and travels as fast as
3,000 kmh, though that is technology

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that will likely be used for military or
space launch systems, researchers said.

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Conclusion:
In conclusion, in this project we have
learnt about
• How magnetic levitations are
achieved (Faraday's Law, Lenz's Law)
• The maglev suspension systems
(EMS, EDS, Inductrack)
• The maglev propulsion systems
Now that we have known how the
technology works, we believe that
maglev systems can be researched
further to be used in advanced
applications and maglev technologies

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are high in demand due to it being
environmentally friendly.
Even though maglevs have drawbacks in
terms of the cost to build it, the major
advantages overshadow the drawbacks
in a long term.