maglev levitation trains
Post on 02-Jun-2018
235 Views
Preview:
TRANSCRIPT
8/11/2019 Maglev Levitation Trains
http://slidepdf.com/reader/full/maglev-levitation-trains 1/23
Maglev trains
By
Vishal Dubey
8/11/2019 Maglev Levitation Trains
http://slidepdf.com/reader/full/maglev-levitation-trains 2/23
Vishal Dubey
Agenda
• Introduction
• Fast facts
• How it works
• Maglev technology• Electromagnetic suspension
• Electrodynamic suspension
•
Stability• Power and energy usage
• Advantages and disadvantages of Maglev Train
8/11/2019 Maglev Levitation Trains
http://slidepdf.com/reader/full/maglev-levitation-trains 3/23
Introduction
• Magnetic levitation transport is a form oftransportation that suspends guides and propels
vehicles through the harnessing of electromagnetic
force.
• The term "maglev" refers not only to the vehicles
but also to the railway system.
• Maglev train uses magnetic levitation from a very
large number of magnets for lift and propulsion.
• Has the potential to be faster, quieter and
smoother than wheeled mass transit systems
8/11/2019 Maglev Levitation Trains
http://slidepdf.com/reader/full/maglev-levitation-trains 4/23
Introduction
• Power needed for levitation is usually not alarge percentage of the overall consumption
• In the present moment there are several
countries working on the development ofMagnetic Levitating trains:
Japan and Germany were pioneers; USA and
Australia are working in on it now.China is not a pioneer having build a maglev
train from Shanghai to its city
8/11/2019 Maglev Levitation Trains
http://slidepdf.com/reader/full/maglev-levitation-trains 5/23
Did you Know?
• Maglev trains can attain speeds of 250 mpheasily (the speed of a jet aircraft).
• The Japanese Maglev's last record was of
581km/h.• The Shanghai Maglev Train can speed up to
431 km/h, or 267 mph.
• The first commercial Maglev was opened in1984 in Birmingham, England, coveringsome 600 meters between its airport andrail hub
8/11/2019 Maglev Levitation Trains
http://slidepdf.com/reader/full/maglev-levitation-trains 6/23
How it works
• A maglev train floats about 10mm abovethe guideway on a magnetic field.
• It is propelled by the guideway itself rather
than an onboard engine by changingmagnetic fields
• Once the train is pulled into the nextsection the magnetism switches so that the
train is pulled on again.• The Electro-magnets run the length of the
guideway.
8/11/2019 Maglev Levitation Trains
http://slidepdf.com/reader/full/maglev-levitation-trains 7/23
How it works
• The train cars use gigantic magnets to hover
above their tracks, decreasing the negative
impact friction has on a train's speed and
allowing the cars to achieve much greater
speeds than normal railroad cars.
8/11/2019 Maglev Levitation Trains
http://slidepdf.com/reader/full/maglev-levitation-trains 8/23
Maglev technology
• There are two primary types of maglev
technology:
• electromagnetic suspension (EMS)
• electrodynamic suspension (EDS)
8/11/2019 Maglev Levitation Trains
http://slidepdf.com/reader/full/maglev-levitation-trains 9/23
Electromagnetic suspension
• In current EMS systems, the train levitates
above a steel rail while electromagnets,
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
the track.
8/11/2019 Maglev Levitation Trains
http://slidepdf.com/reader/full/maglev-levitation-trains 10/23
Advantage
• Proven, commercially available technology
that can attain very high speeds (500 km/h)
• No wheels or secondary propulsion system
needed
8/11/2019 Maglev Levitation Trains
http://slidepdf.com/reader/full/maglev-levitation-trains 11/23
Disadvantage
• The separation between the vehicle and the
guide way must be constantly monitored and
corrected by computer systems to avoid
collision due to the unstable nature of
electromagnetic attraction.
8/11/2019 Maglev Levitation Trains
http://slidepdf.com/reader/full/maglev-levitation-trains 12/23
Electrodynamic suspension
•In Electrodynamic suspension, both therail 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.
• The repulsive force in the track is created
by an induced magnetic field in wires or
other conducting strips in the track.
8/11/2019 Maglev Levitation Trains
http://slidepdf.com/reader/full/maglev-levitation-trains 13/23
Electrodynamic suspension
• At slow speeds, the current induced in these
coils and the resultant magnetic flux 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 cansustain levitation.
8/11/2019 Maglev Levitation Trains
http://slidepdf.com/reader/full/maglev-levitation-trains 14/23
Electrodynamic suspension
• Propulsion coils on the guideway are usedto exert a force on the magnets in the
train and make the train move forward.
• The propulsion coils that exert a force onthe train are effectively a linear motor.
• An alternating current flowing through
the coils generates a continuously varyingmagnetic field that moves forward along
the track.
8/11/2019 Maglev Levitation Trains
http://slidepdf.com/reader/full/maglev-levitation-trains 15/23
Electrodynamic suspension
• The frequency of the alternating current is
synchronized to match the speed of the
train. The offset between the field exerted
by magnets on the train and the appliedfield create a force moving the train
forward.
8/11/2019 Maglev Levitation Trains
http://slidepdf.com/reader/full/maglev-levitation-trains 16/23
Advantage
• Onboard magnets and large margin betweenrail and train enable highest recorded train
speeds (581 km/h) and heavy load capacity
• Successful operations using high temperaturesuperconductors in its onboard magnets,
cooled with inexpensive liquid nitrogen.
8/11/2019 Maglev Levitation Trains
http://slidepdf.com/reader/full/maglev-levitation-trains 17/23
Disadvantage
• Strong magnetic fields onboard the trainwould make the train inaccessible to
passengers with pacemakers or magnetic
data storage media such as hard drives andcredit cards, necessitating the use of
magnetic shielding; vehicle must be
wheeled for travel at low speeds; systemper mile cost still considered prohibitive;
the system is not yet out of prototype
phase.
8/11/2019 Maglev Levitation Trains
http://slidepdf.com/reader/full/maglev-levitation-trains 18/23
Stability
• EMS systems rely on active electronic
stabilization.
• As Maglev vehicles essentially fly, stabilisation
of pitch, roll and yaw is required by magnetic
technology.
8/11/2019 Maglev Levitation Trains
http://slidepdf.com/reader/full/maglev-levitation-trains 19/23
Power and energy usage
• Energy for maglev trains is used to acceleratethe train, and may be regained when the trainslows down.
• Also used to make the train levitate and tostabilise the movement of the train
• Main part of the energy is needed to force thetrain through the air
• Some energy is used for air conditioning,heating, lighting.
8/11/2019 Maglev Levitation Trains
http://slidepdf.com/reader/full/maglev-levitation-trains 20/23
Power and energy usage
• At very low speeds the percentage of power
used for levitation can be significant.
• Also for very short distances the energy used
for acceleration might be considered.
• The power used to overcome air drag
increases with the cube of the velocity, and
hence dominates at high speed
8/11/2019 Maglev Levitation Trains
http://slidepdf.com/reader/full/maglev-levitation-trains 21/23
Advantages of Maglev
•A Maglev is way faster than your usual bullettrain. Maglevs can reach speeds up to 500
kilometres per hour.
• Due to its lack of wheels, MagLevs are quieter
than normal trains, or sometimes even traffic.
• Maglevs use 30% less energy than normal trains.
• In theory, a Maglev and its track would require
very little maintenance since the train never
touches the track there is virtually no wear and
tear.
8/11/2019 Maglev Levitation Trains
http://slidepdf.com/reader/full/maglev-levitation-trains 22/23
Disadvantages of Maglev
• The Maglev's track is much more expensive
than railroad tracks.
• Whole new sets of tracks would have to be
built for the Maglev to run. Many
Transportation vehicles in Europe run on
existing track, like the TGV trains in France.
• Although Maglevs are pretty quiet, noise
caused by air disturbance still occurs.
top related