A presentation on MAGLEV TRains for Graduate level Seminars.

1. MagLev –Magnetic Leviation
Driving without wheels, Flying without wings
BY – Debasis Ray, BS-10-224

2. Magnetic Leviation
 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
leviated.
 A superconductor is perfectly diamagnetic and electromagnets
can exhibit varying levels of ferromagnetism
 Most imoportant application of Magnetic Leviation is
Transrapid magnetic lift trains.

3. Basic Principle of Maglev Trains
Maglev trains have to perform the following functions to
operate in high speeds
1.Leviation
2.Propulsion
3.Lateral Guidance

4. Types of Maglev Trains
Based on the technique used for Leviation the are two types of
Maglev trains
1. Electromagnetic Suspension -Attractive
2. Electrodynamic Suspension -repulsive

5. Electromagnetic Suspension(EMS)
 Electromagnetic Suspension uses electromagnets to leviate
the train

6. Principle of Magnetic Leviation
 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.

7.  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.

8. EMS Levitation Principle:

9. Principle of Propulsion
 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.
 LIM thrusts vary from just a few to thousands of Newtons , depending
mainly on the size and rating
 Speeds vary from zero to many meters per second and are determined by
design and supply frequency

10. EMS Propulsion Principle

11. Gap Sensor
 The attractive force is controlled by a gap sensor that measures the
distance between the rails and electromagnets.

12. 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.

13. Electrodynamic Suspension
 Electrodynamics Suspension uses Superconductors for
levitation, propulsion and lateral guidance

14. Superconductivity
 Superconductivity occurs in certain materials at very low
temperatures.
 When superconductive, a material has an electrical resistance
of exactly zero.
 It is also characterized by a phenomenon called the Miessner
effect. This is the ejection of any sufficiently weak magnetic
field from the interior of the superconductor as it transitions
into the superconducting state.

15. •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.
PRINCIPLE OF MAGNET
LEVITATION

16. •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

17. •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.
PRINCIPLE OF LATERAL
GUIDANCE

18. The SCM (Super Conducting Magnet)
 Each SCM contains 4 SC coils. The SCM features high
reliability and high durability.
 The cylindrical unit at the top is a tank holding liquefied helium
and nitrogen.
 The bottom unit is an SC coil alternately generating N poles
and S poles.

19.  An EDS system can provide both levitation and propulsion
using an onboard linear motor.
 EMS systems can only levitate the train using the magnets
onboard, not propel it forward.

20. EDS Mechanism:

21. Pros and Cons of Different Technologies
TECHNOLOGY PROS CONS
EMS
(Electromagnetic
suspension)
Magnetic fields inside and
outside the vehicle are less
than EDS; proven,
commercially available
technology that can attain
very high speeds
(500 km/h); no wheels or
secondary propulsion
system needed
The separation between
the vehicle and the
guideway must be
constantly monitored and
corrected by computer
systems to avoid collision
due to the unstable nature
of electromagnetic
attraction; due to the
system's inherent instability
and the required constant
corrections by outside
systems, vibration issues
may occur.

22. TECHNOLOGY PROS CONS
EDS
(Electrodynamic
suspension)
Onboard magnets and
large margin between rail
and train enable highest
recorded train speeds
(581 km/h) and heavy load
capacity; has recently
demonstrated (December
2005) successful
operations using high
temperature
superconductors in its
onboard magnets, cooled
with inexpensive liquid
nitrogen
Strong magnetic fields
onboard the train would
make the train inaccessible
to passengers with
pacemakers or magnetic
data storage media such as
hard drives and credit
cards, necessitating the
use of magnetic shielding;
limitations on guideway
inductivity limit the
maximum speed of the
vehicle; vehicle must be
wheeled for travel at low
speeds.

23. Advantages of Magnetic
Levitated Transportation System
 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).
 The operating costs of a maglev system are approximately half
that of conventional long-distance railroads.
 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.
 Maglev vehicle carries no fuel to increase fire hazard
 The materials used to construct maglev vehicles are non-
combustible, poor penetration transmitters of heat, and able to
withstand fire.

24. Current Projects
 Currently operational systems include Transrapid (Germany )
and High Speed Surface Transport (Japan ). There are
several other projects under scrutiny such as the Swiss
Metro, Seraphim and Inductrack. All have to do with personal
rapid transit
 Germany and Japan have been the pioneering countries in
Maglev research

25. Other Applications
 NASA plans to use magnetic levitation for launching of space
vehicles into low earth orbit.
 Boeing is pursuing research in MagLev to provide a
Hypersonic Ground Test Facility for the Air Force.
 The mining industry will also benefit from MagLev.
 There are probably many more undiscovered applications!

26. 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.
 The chief advantages of this type of train are:
Non-contact and non-wearing propulsion, independent of
friction, no mechanical components like wheel, axle.
 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.

27. QUERIES ????