Maglev trains use magnetic levitation to float and propel trains along guideways without touching the track. There are two main levitation techniques: electromagnetic suspension uses electromagnets on the train and ferromagnets on the track to attract the train upwards; electrodynamic suspension uses superconducting magnets on the train that repel from induction coils on the track to levitate the train 10cm above. Propulsion is achieved through propulsion coils on the guideway that create a shifting magnetic field to push the on-board superconducting magnets. Lateral guidance coils ensure the train remains centered through attractive and repulsive magnetic forces.
3. What is meant by maglev….?
Maglev = Magnetic + Levitation.
Any thing which may levitate(raise or float) by means of a magnetic
power is simply called as magnetic levitation.
The term “MAGLEV” can be briefly explained bb using an example of
“MAGLEV TRAINS”
4. Fundamental principle
• Like poles repel while
unlike poles attract each
other.
• One arrangement is shown
here where the bar magnet
is made to levitate
5. BASIC WORKING STAGES OF MAGLEV TRAINS
Maglev trains have to perform the following functions to
operate in high speeds.
1.Levitation
2.Propulsion
3.Lateral Guidance
6. Levitation
• The passing of the
superconducting magnets
through levitation coils on the
sides of the track induces a
current in the coils and creates a
magnetic field . This pushes the
train upward so that it can
levitate 10cm above the track.
• The train doesn’t levitate until it
reaches 50 mph , so it is
equipped with retractable wheels
7. Propulsion
• The propulsion coils located on
the sidewalls on bath 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.
8. Propulsion(cont.…)
• 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.
9. 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
10. Techniques in LEVITATION
There are two types of techniques in LEVITATION of
MAGLEV Trains.
1. Electro magnetic suspension(Attractive)
2. Electro dynamic suspension(Repulsion)
11. Electro magnetic suspension
• Electromagnets are attached to the
train.
• Has ferromagnetic stators on the
track to levitate the train.
• Has guidance magnets on the sides.
• A computer changes the amount of
current to keep the train 1cm from
the track.
12. Electro dynamic suspension
• Super cooled superconductors
under the train. Levitate about
10cm.
• The force in track is created by
induced magnetic field in wires on
conducting strips in the track.
• Naturally stable requires no
feedback.