Transcript Magnetically Levitated Trains (maglev)

Magnetically Levitated
Trains (MagLev)
Ravi Kumar Sahni
M.E 3rd yr
10030104045
The Maglev Train History
In the 1960s in Britain Eric Laithwaite
developed a functional maglev train.
His maglev had 1.6 km of track and
was in detail tested. His research
was stopped in 1973 because lack of
money and his progress was not
enough. In the 1970s, Germany and
Japan also began research and after
some failures both nations developed
mature technologies in the
1990’s…………………………………
…
.
.
What are MagLev trains?
• MagLev uses Electromagnetic Propulsion.
• Trains are thrust forward by positively and
negatively charged magnets.
• The train floats on a cushion of air
eliminating friction.
MagLev “guideways” or
Tracks
• Track repels magnets on undercarriage of
train, sending the train forward.
• Train levitates between 1 and 10 cm
above guideway.
How Transrapid Works
Support System
• The electromagnets on the
underside of the train pull it
up to the ferromagnetic
stators on the track and
levitate the train.
• The magnets on the side
keep the train from moving
from side to side.
• A computer changes the
amount of current to keep
the train 1 cm from the
track.
This means there is no friction
between the train and the track!
Propulsion System
:
Electrodynamic Propulsion is the basis of the movement in a
Maglev system. The basic principle that electromagnetic
propulsion follows is that “opposite poles attract each other
and like poles repel each other”. This meaning that the north
pole of a magnet will repel the north pole of a magnet while
it attracts the south pole of a magnet. Likewise, the south
pole of a magnet will attract the north pole and repel the
south pole of a magnet. It is important to realize these three
major components of this propulsion system. They are:• A large electrical power source
• Metal coils that line the entire guideway
• ·Guidance magnets used for alignment
MAGNETIC LEVITATION SYSTEM
Magnetic levitation means “to rise and float in air”. The
Maglev system is made possible by the use of
electromagnets and magnetic fields. The basic principle
behind Maglev is that if you put two magnets together in a
certain way there will be a strong magnetic attraction and
the two magnets will clamp together. This is called
"attraction". If one of those magnets is flipped over then
there will be a strong magnetic repulsion and the magnets
will push each other apart. This is called "repulsion". On the
basis of this principle, Magnetic Levitation is broken into two
main types of suspension or levitation,
•
•
Electromagnetic Suspension.
Electrodynamic Suspension.
ELECTROMAGNETIC SUSPENSION
SYSTEM
This suspension uses conventional electromagnets located on
structures attached to the underside of the train; these structures then
wrap around a T-shaped guiderail. This guiderail is ferromagnetic,
meaning it is made up of such metals as iron, nickel, and cobalt, and
has very high magnetic permeability. The magnets on the train are
then attracted towards this ferromagnetic guiderail when a “current
runs through the guiderail and the electromagnets of the train are
turned on”. This attraction lifts the car allowing it to levitate and move
with a frictionless ride. “Vehicle levitation is analyzed via on board
computer control units that sample and adjust the magnetic force of a
series of onboard electromagnets as they are attracted to the
guideway”.
ADVANTAGES OF E.M.S
• Train interlocks with the guiderail making it
impossible to derail
• No contact between the train and its track. So
power loss minimum
• Reduces the noise and maintenance of the
system
ELECTRODYNAMIC SUSPENSION
SYSTEM
EDS uses superconducting magnets (SCM) located
on the bottom of the train to levitate it off of the track.
By using super cooled superconducting magnets, the
electrical resistance in superconductors allows
current to flow better and creates a greater magnetic
field. The downside to using an EDS system is that it
requires the SCMs to be at very cold temperatures,
usually around 5 K (-268ºC) to get the best results
and the least resistance in the coils. The Japanese
Maglev, which is based on an EDS system, uses a
cooling system of liquid nitrogen and helium.
Levitation
•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.
Lateral Guidance
•When one side of the train nears the side of the guide
way, 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.
Levitation systeM’s Power suPPLy
 Batteries on the train power the system, and
therefore it still functions without propulsion.
 The batteries can levitate the train for 30
minutes without any additional energy.
 Linear generators in the magnets on board the
train use the motion of the train to recharge the
batteries.
 Levitation system uses less power than the
trains air conditioning.
BLOCK DIAGRAM
FREQUENCY
REFERENCE
SIGNAL FOR
SPEED
CONTROL
CONTROLLER
THREEPHASE
POWER
INPUT
TRAIN WITH
SPEED
SENSOR
TRACK
MagLev vs. Conventional Trains
MagLev Trains
Conventional Trains
No Friction = Less
Maintenance
Routine Maintenance
Needed
No Engine = No fuel
required
Engine requires fossil
fuels
Speeds in excess of
300 mph
Speeds up to 110 mph
ADVANTAGES
Safety
•The trains are virtually impossible to derail because the
train is wrapped around the track.
•Collisions between trains are unlikely because computers
are controlling the trains movements.
•Earth Quake Proof
Maintenance
• There is very little maintenance because there is no
contact between the parts.
Comfort
•The ride is smooth while not accelerating..
Speed
•The train can travel at about 300 mph. (Acela can only go 150 mph)
•For trips of distances up to 500 miles its total travel time is equal to a
planes (including check in time and travel to airport.)
•It can accelerate to 200 mph in 3 miles, so it is ideal for short jumps.
•Noise Pollution
•The train makes little noise because it does not touch the
track and it has no motor. Therefore, all noise comes from
moving air. This sound is equivalent to the noise produced
by city traffic.
Better for the Environment
• Less energy consumption because no railtrack friction
• Requires no fossil fuel which can harm the
environment.
• Less noise pollution since the train never
hits the track
• MagLev guide ways and trains take up
less space than conventional trains