UNIT-V FMM.HYDRAULIC TURBINE - Construction and working
Maglev Technology
1. INTRODUCTION TO MAGNETIC
LEVITATION
&
ITS APPLICATION
Driving without wheels, Flying without wings
by
VISHWANATH
NEHA(12K41A0270)
Under the guidance of
O.SRIKANTH
(Asst. prof)
3. 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 Diamagnetism object can be
levitated.
A superconductor is perfectly diamagnetic and electromagnets
can exhibit varying levels of ferromagnetism.
Most important application of Magnetic Levitation is Transrapid
magnetic lift trains.
4. Basic Principle of Maglev Trains
MagLev trains have to perform the
following functions to operate in high
speeds
1.Levitation
2.Propulsion
3.Lateral Guidance
5. Types of Maglev Trains
Based on the technique used for Levitation there
are two types of MagLev trains
1. Electromagnetic Suspension -Attractive
2. Electrodynamic Suspension -Repulsive
8. 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.
9. 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.
11. 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.
12. Gap Sensor
The attractive force is controlled by a gap sensor that
measures the distance between the rails and
electromagnets.
13. 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.
15. 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.
16. 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.
17. •The passing of the superconducting magnets by figure eight
levitation coils on the side of the track 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
18. •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
19. •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
20. 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.
21. 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.
22. 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!