1. AMITY UNIVERSITY
Department of Mechanical & Automation Engineering
Project Report
MAGNETIC LEVIATION
Program: Mechanical & Automation Engineering
Prepared for:
Prof. V. VERMA
Names Student ID Signature*
ANKUR PANDEY A7605408058
SHIV PRASHANT A7605408064
ANKUR DWIVEDI A7605408051
RAHUL AWASTHI A76054080
ASHISH SINGH A7604080
JITESH KESHWANI A760540805
GAURAV MAKHIJANI A760540805
.

2. PERMANENT MAGNETIC LIFTER
Usage:
Widely used in lifting and transporting flat and round steel loads , without the need
for
slings, clamps, or other holding devices, no damage to the surface of lifted goods,
saving the lifting time and optimizing the piled up area.
Features:
1）Without power, No risk in the condition of no electrical source .
2）Use high-energy Permanent magnetic material to be smaller volume .
3) A great concentration of power with a safety factor 1:3.5 on the suggested load.
4) Optimized magnetic circuit together with appearance design made the structure of
the product simple and firm ,even with a large air gap.
5) Special handle-operating switch with safety bottom
6) Type V through at the bottom of the holding face ; can lift round stick and steel
panel. Type choice:
Please choose the related type according to the thickness ,weight of the lifted objects,
material character, magnetic area , surface finish ，the space between it and magnetic
lift, or the weight balance condition of the lifted objects.
Please refer to the application and safety notes for each respective lifter for safe
operation.
S.SHARANAPPA & K.DINESH
sharantillu@yahoo.com dinesh_withyou@yahoo.co.in

3. ABSTRACT
MAGNETIC LEVITATION –It is use of magnetic fields to levitate a metallic
object .By
manipulating magnetic fields and controlling their forces an object can be
levitated.
Because of the growing need for quicker and more efficient methods for
moving
people and goods, researchers have turned to a new technique, one using
electromagnetic rails and trains. This rail system is referred to as magnetic
levitation,
or maglev. Maglev is a generic term for any transportation system in which
vehicles
are suspended and guided by magnetic forces. Instead of engines, maglev
vehicles use
electromagnetism to levitate (raise) and propel the vehicle. Alternating
current
creates a magnetic field that pushes and pulls the vehicle which weighs
almost about
1500 tonnes and keeps it above the support structure, called a guide way.
Another
major application of magnetic levitation is ELEKTROMAG. "ELEKTROMAG"--
Magnetic
Sheet Floaters have been designed for easy handling of stacked sheets in production
jobs.
MAGNETIC LEVITATION:
INTRODUCTION:
The word levitation is derived from a latin word “LEVIS”,which means light.
Magnetic
levitation is the use of magnetic fields to levitate a metallic object. By manipulating
magnetic
fields and controlling their forces an object can be levitated. When the like poles of
two
permanent magnets come near each other, they produce a mutually repulsing force
that grows
stronger as the distance between the poles diminishes. When the unlike poles of two
permanent
magnets are brought close to each other, they produce a mutually attractive force that
grows
stronger as the distance between them diminish A levitation system designed around
the
attractive force between unlike poles would require a perfect balance between the
attractive
magnetic force and the suspended weight In the absence of a perfect lift and weight
force profile,
the conveyance would either be pulled up toward the magnets or would fall. This
simple
illustration of magnetic levitation shows that the force of gravity can be
counterbalanced by
magnetic force.

4. There are two ways of levitations,
1.Active 2. Passive.
In an active levitation system, electromagnets are coupled to amplifiers that receive
signals from
controllers. These controllers process signals from sensors that change the magnetic
force to
meet the needs of the magnetic system.
Passive magnetic levitation systems are impractical without a stabilizing ingredient.
Diamagnetic levitation can be used to add stability to passive levitation systems. The
combination of passive and diamagnetic levitation is a functional approach to many
magnetic
levitation application.
Magnetic levitation is used in transportation particularly in monorails,and in levitating
displays.
Magnetic bearings have been used in pumps, compressors, steam turbines, gas
turbines, motors,
and centrifuges, but these complex applications require electromagnets, sensors, and
control
systems.
Major applications of magnetic levitation are:
1. Transportation: Maglev trains.
2. Moving of metallic objects in steel industry: Magnetic floaters.
3. Military applications:Rail-gun.
MAGLEV:
Powerful electro magnets are used to develop high-speed trains called maglev
trains. These will float over a guideway using the basic principles of magnets to
replace the old
steel wheel and track trains.
Magnetic levitation (maglev) is a relatively new transportation technology in which
noncontacting
vehicles travel safely at speeds of 250 to 300 miles-per-hour or higher while
suspended, guided,
and propelled above a guideway by magnetic fields. The guideway is the physical
structure along
which maglev vehicles are levitated. Various guideway configurations, e.g., T-shaped,
U-shaped,
Y-shaped, and box-beam, made of steel, concrete, or aluminum, have been proposed.
A super high-speed transport system with a non-adhesive drive system that is
independent of
wheel-and-rail frictional forces has been a long-standing dream of railway engineers.
Maglev, a combination of superconducting magnets and linear motor technology,
realizes
super high-speed running, safety, reliability, low environmental impact and minimum
maintenance.
Principle of Maglev
Maglev is a system in which the vehicle runs levitated from the guideway
(corresponding to the
rail tracks of conventional railways) by using electromagnetic forces between
superconducting

5. magnets on board the vehicle and coils on the ground. The following is a general
explanation of
the principle of Maglev.
Principle of magnetic levitation
The "8" figured levitation coils are installed on
the sidewalls of the guideway. When the onboard
superconducting magnets pass at a high
speed about several centimeters below the center
of these coils, an electric current is induced
within the coils, which then act as
electromagnets temporarily. As a result, there
are forces which push the superconducting
magnet upwards and ones which pull them
upwards simultaneously, thereby levitating the
Maglev vehicle.
Principle of lateral guidance
The levitation coils facing each other are
connected under the guideway, constituting a
loop. When a running Maglev vehicle, that is a
superconducting magnet, displaces laterally, an
electric current is induced in the loop, resulting
in a repulsive force acting on the levitation coils
of the side near the car and an attractive force
acting on the levitation coils of the side farther
apart from the car. Thus, a running car is always
located at the center of the guideway.
Principle of propulsion
A repulsive force and an attractive force induced
between the magnets are used to propel the
vehicle (superconducting magnet). The
propulsion coils located on the sidewalls on both
sides of the guideway are energized by a threephase
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
.
Figure 1 depicts the three primary functions basic to maglev technology: (1) levitation
or
suspension; (2) propulsion; and (3) guidance. In most current designs, magnetic forces
are used
to perform all three functions, although a nonmagnetic source of propulsion could be
used. No
consensus exists on an optimum design to perform each of the primary functions.
Suspension Systems
The two principal means of levitation are illustrated in Figures 2 and 3.
Electromagnetic

6. suspension (EMS) is an attractive force levitation system whereby electromagnets on
the vehicle
interact with and are attracted to ferromagnetic rails on the guideway. EMS was made
practical
by advances in electronic control systems that maintain the air gap between vehicle
and
guideway, thus preventing contact.
Variations in payload weight, dynamic loads, and guideway irregularities are
compensated for by
changing the magnetic field in response to vehicle/guideway air gap measurements.
Electrodynamic suspension (EDS) employs magnets on the moving vehicle to induce
currents in
the guideway. Resulting repulsive force produces inherently stable vehicle support
and guidance
because the magnetic repulsion increases as the vehicle/guideway gap decreases.
However, the
vehicle must be equipped with wheels or other forms of support for "takeoff" and
"landing"
because the EDS will not levitate at speeds below approximately 25 mph. EDS has
progressed
with advances in cryogenics and superconducting magnet technology.
Figure 2 and Figure 3
Propulsion Systems "Long-stator" propulsion using an electrically powered
linear motor
winding in the guideway appears to be the favored option for high-speed maglev
systems. It is
also the most expensive because of higher guideway construction costs.
"Short-stator" propulsion uses a linear induction motor (LIM) winding onboard and a
passive
guideway. While short-stator propulsion reduces guideway costs, the LIM is heavy
and reduces
vehicle payload capacity, resulting in higher operating costs and lower revenue
potential
compared to the long-stator propulsion. A third alternative is a nonmagnetic energy
source (gas
turbine or turboprop) but this, too, results in a heavy vehicle and reduced operating
efficiency.
Guidance Systems
Guidance or steering refers to the sideward forces that are required to make the
vehicle follow
the guideway. The necessary forces are supplied in an exactly analogous fashion to
the
suspension forces, either attractive or repulsive. The same magnets on board the
vehicle, which
supply lift, can be used concurrently for guidance or separate guidance magnets can
be used.
You can easily create a small electromagnet yourself by connecting the ends of a
copper wire to
the positive and negative ends of an AA, C or D-cell battery. This creates a small
magnetic field.

7. If you disconnect either end of the wire from the battery, the magnetic field is taken
away.
The magnetic field created in this wire-and-battery experiment is the simple idea
behind a
maglev train rail system. There are three components to this system:
• A large electrical power source
• Metal coils lining a guideway or track
• Large guidance magnets attached to the underside of the train
The big difference between a maglev train and a conventional train is that maglev
trains do not
have an engine -- at least not the kind of engine used to pull typical train cars along
steel tracks.
The engine for maglev trains is rather inconspicuous. Instead of using fossil fuels, the
magnetic
field created by the electrified coils in the guideway walls and the track combine to
propel the
train.
Photos courtesy Railway Technical Research Institute
Above is an image of the guideway for the Yamanashi maglev test line in Japan.
Below is an illustration that shows how the guideway works.
The magnetized coil running along the track, called a guideway, repels the large
magnets on the
train's undercarriage, allowing the train to levitate between 0.39 and 3.93 inches (1
to 10 cm)
above the guideway. Once the train is levitated, power is supplied to the coils within
the
guideway walls to create a unique system of magnetic fields that pull and push the
train along the
guideway. The electric current supplied to the coils in the guideway walls is
constantly
alternating to change the polarity of the magnetized coils. This change in polarity
causes the
magnetic field in front of the train to pull the vehicle forward, while the magnetic
field behind
the train adds more forward thrust.
Maglev trains float on a cushion of air, eliminating friction. This lack of friction and
the trains'
aerodynamic designs allow these trains to reach unprecedented ground transportation
speeds of
more than 310 mph (500 kph), or twice as fast as Amtrak's fastest commuter train.
Japanesse MLU-002 maglev train. The tracks enclose it on the sides and underneath
How fast can they go?
On test runs maglev trains have been able to exeed 300mph. In Germany the top
speed of a
maglev train was 312mph and Japan's maglev trains reached 323mph in 1979
shattering the
record books. With advances on maglev trains, people say it will be able to go
600mph to
1000mph in the future. If maglev trains succeed they will revolutionize the way we
get
around and dramatically reduce travel time.

8.  ADVANTAGES OF MAGLEV OVER CONVENTIONAL TRAINS :
 Conventional trains use an engine where as maglev vehicles instead of engines use
electro magnetism to levitate(raise) and propel the vehicle.
 Instead of using fossil fuels, the magnetic field created by the electrified coils in
the
guideway walls and the track combine to propel the train.
 Using a magnet's repelling force to float above magnets in the guideway, the
trains aren't
hampered by friction where as, Conventional trains are noisy due to the friction
between
their wheels and the steel rails, but maglev trains are much quieter.
These maglev trains are uncomparablely faster than normal conventional trains.
 Moreover as these maglev trains work using electromagnetic induction using
electricity
these are pollution free.
 IN COMPARISON WITH TGV :
 TGV-train de grande vitese,which means jets on land.
 Today, the fastest train in regular passenger service is France's TGV. It
actually topped out during a speed run at 319 mph. Japan has a
demonstration maglev train that went 31 mph faster than that, but not
without problems.
 While the TGV can reach such speeds, it does so by using tremendous
amounts of power, and the noise is incredible. The TGV normally travels
closer to 150 mph.
 Maglev trains don't have such problems.
Using a magnet's repelling force to float above magnets in the guideway,
the trains aren't hampered by friction.
Are Maglev trains safe?
Maglev trains have proven to be exceptionally safe, quiet, and fast. Because there's no
friction
with the ground, maglev trains are much more quiet than trucks and automobiles. The
only sound caused by the trains is the whoosh as the train goes by from the air
friction.
Farmers in Germany who have trains running over their fields, when asked about how
the
feel about the trains running through their farm replied "We don't even know it's
there".
Cows don't even lift their heads when trains come through at 250mph. Maglev trains
are
also almost accident free. They are above any obstacles on the ground and are
enclosed in
or around the track. Also the propoltion system caused by the magnetic fields
disallows
trains to come to close to other trains on the track.
WHY MAGLEV???????

9.  Permits speed of vehicles of 250 to 300MPH and even higher.
 High reliability and less susceptible to congestion and weather conditions than air
or
highway travel.
 Maglev is petroleum independent with respect to air and auto because of maglev
being
electrically powered.
 Maglev is less polluting as fossil fuels are not used.
 Maglev has higher capacity than air travel.
 High safety and more convenient mode of transport.
INTRODUCTION
"ELEKTROMAG" Magnetic Sheet Floaters have been designed for easy
handling of stacked sheets in production jobs, It cuts costs on any job where steel
sheets are handled in production jobs. They help boost press and press brake
production by eliminating the need to fumble with thin oily sheets. The steel
sheets can be of any length,width or shape. Everlasting Powerful Permanent
Magnet Sheet Floaters reduce operating cost.
HOW IT WORKS
A Sheet Floaters is positioned
against the stack of steel
sheets. The magnetic field passes
in the steel sheets and they become
magnetised in the area touching the
sheet floater. As a result,the sheets
near the top of the stack separate as
there is no load on the top sheet.
When the topmost sheet is removed the next lower sheet automatically
moves up. This action repeats until all sheets have
been removed.
Sheet Floaters may be used singly,in pairs or even in greater numbers depending upon
job requirements. Floating is accomplished by placing two or more units in position
which cause the entire top sheet to magnetically float over the others. Separation is
achieved by using one unit at an edge or corner of the sheet.
APPLICATION
The Sheet Floaters can be used for heavy and
light gauges, large and small sheets, high and
low stacks, dry and oily sheets, irregular and
round shapes, polished, painted or printed
sheets. It can best be used for protection of
polished, painted and furnished surfaces from
scratches.
CONSTRUCTION
Powerful Permanent Magnets are housed in an all-welded steel housing. Mounting
holes are
provided for fixing the floaters at any position. A handle is provided for easy shifting
from
one job to another.

10. RANGE AND SIZES
"ELEKTROMAG" offers the widest range of strengths necessary for different
thickness and
for various sizes and shapes of material. Quotation can be submitted on receipt of the
following information:
1. Gauge
2. stack height
3. shape
4. size of material
that needs to be handled on Sheet Floater. In fact there is a Sheet
Floater for every job.
ADVANTAGES OF PERMANENT MAGNETIC SHEET FLOATERS
 Save labour
 Eliminate accidents
 Reduce handling costs
CONCLUSION
The future of magnetic levitation
 Magnetic levitation is a phenomena that is likely to have considerable potential in
the
future. Particularly through the use of superconductive levitation.
 A new idea for magentic levitation is in the use of storage of energy. Very
basically it
uses a rotating ring (flywheel) that stores (kinetic) moving energy which can be
'extracted'
MAGLEV
Magnetic Levitation
The following paper was submitted and presented by me and my colleague in
2002 during our Engineering Degree Course.
Maglev is a technology which uses magnetic forces to suspend vehicles in air,
hence eliminating friction. This allows vehicles to achieve very high speeds which
can revolutionize the ground transportation. The technology is environment
friendly but is yet in development stage.
2002
Ashutosh Agrawal
Email: aagrawal.ie@gmail.com
Blog: www.frontiers2explore.blogspot.com
LinkedIn: www.linkedin.com/in/itsmeashu/
2
MAGLEV:A NEW PROMISE
By:

11. Ashutosh Agrawal Anil Kumar Soni
B.Tech, final year, B.Tech, final year,
Mechanical Engg. Mechanical Engg.
Kamla Nehru Institute of Technology, Sultanpur
3
CONTENTS
1. Abstract
2. Introduction
3. Levitation and Guidance Systems
4. Propulsion System
5. Guideway Configurations
6. Maglev Transportation
7. Maglev Launch System
8. Conclusion
9. References
4
ABSTRACT
Magnetic Levitation is an advanced technology known as Maglev in short. In this
magnetic
forces lift, propel and guide a vehicle few centimeters above a guideway using magnetic
forces. The physical contact between vehicle and guideway is eliminated and permits
cruising
speeds in range of 500 km/h. The levitation and guidance is achieved by either magnetic
attraction ( EMS - Electro Magnetic Suspension ) or repulsion ( EDS - Electro Dynamic
Suspension ). The propulsion is achieved by linear motor of either ‘long stator’ or ‘short
stator’.
Because of its high speed, Maglev may be able to offer competitive trip-time savings in
transportation. Many feasible concepts of Maglev transportation like Skytran (for
intracity
transportation), autoshuttle, transrapid etc have been developed and so also the various
possible configurations of the guideways like ‘Y’, ‘U’, ‘T’ and Box beam.
The capability of Maglev of controlled lift of thousands of pounds into the air and high
acceleration has ushered it into area of space vehicle launch systems.
The paper focuses on the technical aspects of Maglev that make this ‘flying in air’
phenomenon possible and its profitable applications in transportation and space launch.
5
INTRODUCTION
‘Trains that fly in air’, has fascinated many, but only a few know the magnificent yet
simple
principle behind it. From long ago magnetic forces has been known as capable of
suspending
ferromagnetic particles in air. But it was at the turn of 20th century, the concept of
magnetically levitated trains was first identified by two Americans, Robert Goddard and
Emile Bachelet1. By the 1930’s Germany’s Hermann Kemper demonstrated the concept
and
in 1968 Americans James R. Powell and Gordon T. Danby were granted a patent on their
design of Maglev train1.
A Maglev train is levitated (i.e. lifted), guided and propelled by magnetic fields a few

12. centimeters above the guideway, completely eliminating the physical contact between
train
and guideway and enabling the speed up to 500km/h1.
Over the past two decades, several countries including Germany, Japan and America have
conducted R&D programs in Maglev technology. Germany and Japan have invested over
$1billion each to develop and demonstrate Maglev technology for High Speed Ground
Transportation (HSGT) 1.
Maglevs has expanded its area of application with NASA experimenting on the use of
Maglev
for the cheaper launches of spacecrafts.
LEVITATION AND GUIDANCE SYSTEMS
As shown in the fig.[1] levitation implies vertical support and guidance implies lateral
support
to ensure that train does not run off the track. Same principle is employed for both
support
and guidance.
There are two principal means of both guidance and levitation.
 Attractive force system technically known as Electro Magnetic Suspension or EMS.
 Repulsive force system technically known as Electro Dynamic Suspension or EDS.
Electro Magnetic Suspension: In this electromagnets are attracted to ferromagnetic rails
on
the guideway.
6
In the figure below the bar in blue colour is the guiderail and the one in red is
electromagnet
on underside of the train.
Variations in payload weight, dynamic loads and guideway irregularities are compensated
for
by changing the magnetic field in response to air gap measurements.
Electro Dynamic Suspension: In this the magnets on the moving vehicle induce currents
in
the induction coils of guideway as it passes over it. The resulting repulsive force suspends
the
vehicle in air. This system is inherently stable for both support and guidance because
magnetic repulsion increases as the air gap decreases.
However this system requires speed approx. upto 40km/h1 to levitate the vehicle. So the
vehicle must be equipped with some support like wheels for speed below the 40km/h
limit.
This flaw as it may be seen is an advantage as it provides fail safe security in case if
electrical
drive systems fail. The vehicle will be still levitated at speeds above the 40km/h and will
slowly touch down the rails as speed will drop. In case of EMS system if onboard
electrical
system were to fail then vehicle will touch down at very moment at high speed of
500km/h
and the result can be catastrophic.
The induction coils that can be used are of two types:
 Simple single coil of shape ‘_’.
 ‘8’ shaped coil. The system is called null flux system and is worth discussing.
Drift between the rails and levitation magnets caused by wind or when
the train rounds a curve.
The gap widens between rail and track because of shortage of magnetic

13. force.
The widening gap is sensed by gap sensors and the current is increased in
leviatation magnets to increase the magnetic attraction till train comes
back directly above the guide rails.
7
Null Flux System: In this system induction coils are wound as figure ‘8’. These coils are
mounted on sidewalls of guideway.
If vehicle’s magnetic field passes directly through centre of the ‘8’ shaped coil, the net
flux is
zero. But if field is slightly below their centre, electric current is induced within the coils
which then act as electromagnets temporarily. The result is a repulsive force in lower half
of
the coil pushing it upward and attractive force in upper half of the coil pulling it upward.
Both
act simultaneously to levitate the vehicle. Please refer fig.[2].
There are currently two choices of magnets used on the vehicle in EDS:
 Superconducting magnets: The electrical resistivity of a superconducting material
becomes zero below a certain critical temperature. The current flows in the material
without any loss. So in a superconducting solenoid large current will keep circulating for
long periods. A superconducting magnet require small space, less material and produce
magnetic field upto 5-10 T. Eg: TcYbaCuO, critical temp:77K5.
 Permanent magnets: the pemanent magnets used are that of Ne-Fe-B (Neodymium,
Iron
& Boron) which are arranged in Halbach array4 (invented by Klaus Halbach).
Halbach array: In this permanent magnets are arranged in alternate vertical and
horizontal pattern so that the magnetic-field lines reinforce one another below the array
but cancel one another above it. Refer fig.[3].
When moving, the magnets induce current in the track's circuits(‘_’ shaped coil), which
produces an electromagnetic field that repels the array, thus levitating the train car.
Halbach arrays can also provide lateral stability if they are deployed alongside the track's
circuits. Refer fig.[4].
PROPULSION SYSTEM
There are two alternatives for propulsion:
Non-magnetic energy source: gas turbine or turboprop can be used for the propulsion but
this
results in a heavy vehicle and reduced operating efficiency.
Magnetic energy source: It employs the principle of linear motor for the propulsion.
8
A repulsive force and an attractive force induced between the magnets are used to propel
the
vehicle. 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 magnets are attracted and pushed by the shifting
field,
propelling the Maglev vehicle
There are two possible cnfigurations of linear motor:
Long Stator: ‘Long Stator’ propulsion uses an elctrically powered linear motor winding
in
the guideway.
Short Stator: In this the motor winding is on the vehicle and the guideway is passive.
Of the two the Long Stator propulsion is having high initial cost but it has high payload

14. capacity and lower operating cost and studies indicate it to be a favoured option.
The drive coils in long stator can be interspersed among the track's levitating circuits. An
array of substations along the wayside sends three phase AC power, in synchronization
with
train motion, to the windings. The power flows in a linear sequence to generate a
magnetic
wave along the guideway. Only the section of the guideway under the train receives
power as
vehicle rides on the magnetic wave.
GUIDEWAY CONFIGURATIONS
The one of the main advantages of maglev is the flexibility it offers in guideways
configurations.
 Box Beam: In this vehicle straddles on a concrete box beam guideway. Interaction
between the vehicle magnets and laminated Aluminium ladder on each guideway
sidewall generates lift and guidance. Propulsion windings are also attached to the
guideway sidewalls. Fig.[5].
9
 U - shaped guideway: Null flux (8-shaped) levitation coils located on the sidewalls
provide levitation and guidance. LSM propulsion coils are also located on sidewalls.
 T - shaped guideway: The vehicles wrap around this T shaped ferromagnetic
guideway.
Levitation and guidance are based on EMS system. The electromagnets for levitaion are
located underneath the guideway and that for guidance are mounted on the edge of
guideway. The guideway has LSM windings which interact with lift electromagnets
mounted on vehicle. Fig.[6].
 Y - shaped guideway: Here the vehicle wraps around a Y-shaped ferromagnetic
guideway. The advantage is that a common set of vehicle magnets are used for levitation,
guidance and proplulsion unlike in T-shaped which required two separate vehicle
magnets. The pole faces of vehicle electromagnets are attracted to the underside of the
ferromagnetic guideway. The guideway has LSM windings for propulsion.
MAGLEV TRANSPORTATION
Due to the flexibility maglev offers many concepts of transportation which have been
worked
out, and the possibilities of many more are immense.
We discuss here the concepts whose feasibilities have been established through extensive
studies.
 Maglev Trains: Maglev trains are capable of travelling at twice the speed of their
fastest
counterparts wheel-on-rail train TGV of France. The result is considerable trip time
savings and faster trips which makes its commercialisation feasible.
Various commercial maglev train projects are in progress all over the world.
1. Maglev track connecting cities of Washington and Baltimore10.
2. Maglev track between Hamburg and Berlin and between downtown Pittsburgh & the
airport in Germany1 .
3. 34 km long Maglev track connecting Longyang Road Station on Metro Line II with
Pudong International Airport in China, designed for 433 kmph speed9.
4. Maglev track between Osaka and Tokyo in Japan which would reduce the trip time
from bullet train’s 2 hours 30 mins to 1 hour1.
 Autoshuttle6: It is a German dual-mode concept that utilizes Maglev carriers to
transport a
variety of conventional vehicles like cars, trucks etc. Fig.[7].

15. 10
 Skytran7: Small podlike two-passenger cars would be suspended from a monorail-type
track that would support the levitating circuits. The cars would be available, on call, at
each station in the system. After the passengers board a car, it would glide up to the main
track and merge with the traffic speeding by the station at 160 kmph. As a car approaches
its destination, it would switch to an exit track, dropping down to the station to allow the
passengers to disembark. Fig.[8].
MAGLEV LAUNCH SYSTEM
Studies by NASA have shown that if their rockets could be accelerated up a sloping track
to
speeds on the order of Mach 0.8 (950 kilometers per hour) before the rocket engines were
fired up, it could substantially cut the cost of launching satellites. Such a system could
reduce
the required rocket fuel by 30 to 40 percent, thereby making it easier for a single-stage
vehicle
to boost a payload into orbit4. Refer fig.[9].
NASA envisions a track a mile and a half long ( 2.4 km ) on which a winged craft would
ride
on a sled that would be magnetically levitated and propelled at an acceleration of 2 gs
( 19.6
m/s2 ) until it reaches a speed of 400 milesph (643.6 kmph). The contestants of this NASA
project are PRT Advanced Maglev Systems, Foster-Miller and Lawrence Livermore
National
Lab3.
PRT Advanced Maglev Systems of Park Forest built a 50 feet (15.24 m) long working
model
of spacecraft maglifter at Marshall Centre in Huntsville, Ala. The test vehicle weighing
30 lb
reached speeds of 60 mph (96.54 kmph) in less than half a second3.
Foster-Miller’s maglev launch system for NASA uses two sets of windings on the track.
One
set forms the stator that propels the vehicle and the other ,‘Null-Flux’, windings levitate
and
guide the vehicle. The experimental track built by it is 40 feet (12.2 m) long is in two
parts:
the first half contains the drive motor and the other comprise a magnetic brake. It was
able to
gain 58 mph (93 kmph) in 20 feet (6.1 m) or in three-tenth of a second3.
Lawrence Livermore National Laboratory in Livermore, California is building a mag-
lifter
using permanent magnets arranged in Halbach array, thus avoiding use of
superconductors
which requires cooling at cryogenic temperatures. A 20 feet (6.1 m) long working model
has
been built and a larger working model is under construction at Livermore3.
11
The goal of using magnetic levitation is to help to reach a target of reducing the cost of
launching payload from the present $10,000 a pound to less than $1000 and perhaps
eventually to $200 a pound or so3.
ADVANTAGES OF MAGLEV
_ Unlike trains or cars there is no surface contact or friction to slow them down. More
speed

16. = More passengers.
_ Faster trips :- High peak speed and high acceleration/braking enable average speed 3-4
times the national highway speed limit of 65 mph (105 kmph).
_ High reliability :- Less susceptible to congestion and wheather conditions than air and
highway.
_ Petroleum independence with respect to air and auto as a result of being electrically
powered.
_ Less polluting as a result of being electrically powered. Emissions can be controlled
more
effectively at the source of electric power generation than at many points of consumption,
such as with air and automobile usage.
_ Higher capacity than air. At least 12,000 passengers with potential for even higher
capacities at 3-4 minutes headways1.
_ High safety – both percieved and actual as based on the experiments.
_ Convinience and Comfort – due to high frequency of service, vibration free, smooth-
assilk
train rides and quieter. At speeds below 155 mph (249.4 kmph) the noise produced by
Maglev trains is less than that by conventional trains. At speeds above 155 mph, most of
the noise produced by vehicle is of aerodynamic origin, wheather it is on rail or levitated1.
12
CONCLUSION
Any practical and commercial use of maglev has to be examined for technical & financial
feasibility.
The technical feasibility has been stablished by status of Japanese MLU002 prototype
system
currently being run in yamanshi test line5 & by German transrapid system at Emsland test
facility8. Both test systems have have supplemented Maglev as the promise of a faster,
smoother, clean and safer ride.
The other aspect of financial feasibility is subjective to a country. To judge its financial
feasibility its cost and revenue estimates have to be extensively studied in context of the
geography, demography and existing transportation systems. Studies in America were
carried
out by National Maglev Initiative (NMI) evaluated Maglev potential and in short their
conclusion was that a 300 mph ( 483 kmph ) is entirely feasible1. Various commercial
projects
in America, Germany, China and Japan should leave no room of doubt for its economical
viability. The need to upgrade this technology for a nation can be summed up in one
sentence
that high mobility is linked with eonomic growth and productivity of nation.
India has the most complex, widespread rail network which is now bogged down by
congestion. Maglev provides the flexibility to equip existing steel tracks with magnetic
levitation (based on EDS) and propulsion system. This will help in operating both maglev
and
conventional trains on same track. The possible incorporation of both steel track and
maglev
guideway is hinted in figure. By this we can replace the conventional trains with maglev
trains in phased manner.
The space launch systems based on maglev are also feasible as indicated by NASA.
Various
test models have proved its technical feasibility and cost studies by NASA clearly
indicate

17. cheaper launching in future.
Over the years India has developed strong infrastructure for space exploration and has its
own
array of launch vehicles and a reusable vehicle ‘Avataar’ on the cards. With NASA in
persuit
of low cost maglev launch its time that India too must venture into this field so that it can
compete, in the growing billion dollar market of satellite launch, in future.
13
REFERENCES
1. National Maglev Initiative (NMI), formed by DOT, DOE, USACE and others, (U.S.),
‘Final Report on the National Maglev Initiative’, www.bts.gov .
2. Leo O’ Connor, Associate Editor,’US Developers Join Magnetic Rail Push’,
Mechanical
Engineering, ASME, NewYork, August 1993.
3. Barbara Wolcott, ‘Induction for the Birds’, Mechanical Engineering, ASME,
NewYork,
Feb 2000.
4. Dr. Richard F. Post., Inventor of Inductrack Passive Magnetic Levitation, ‘Maglev: A
New Approach’, Scientific American, Jan 2000.
5. Railway Technical Research Institute, Japan, ‘Maglev’, www.rtri.or.jp .
6. ‘Autoshuttle’, www.autoshuttle.de .
7. ‘Skytran’, www.skytran.net .
8. ‘Transrapid International’, www.transrapid.de .
9. ‘Shanghai Builds Maglev Rail Line’, www.goldsea.com
10. ‘Baltimore-Washington Project’, www.bwmaglev.com
Downloadedfrom
FaaDoOEngineers.com
“DRIVING WITHOUT WHEELS,
FLYING WITHOUT WINGS” 2

18. Abstract
This paper “Driving without wheels, Flying without wings” deals with the present
scenario of magnetic levitation (maglev) with Linear induction motor (LIM) .The
magnetically levitated train has no wheels, but floats-- or surfs-- on an electromagnetic
wave, enabling rides at 330 miles per hour. By employing no wheels, maglev eliminates
the friction, and concomitant heat, associated with conventional wheel-on-rail train
configurations. There are two basic types of non-contact Maglev systems Electro
Dynamic Suspension (EDS), and Electro Magnetic Suspension (EMS). EDS is
commonly known as "Repulsive Levitation," and EMS is commonly known as
"Attractive Levitation." Each type of Maglev system requires propulsion as well as
"levitation." The various projects above use different techniques for propulsion, but they
are all variations of the Linear Induction Motor (LIM) or Linear Synchronous Motor
(LSM).The conversion to a linear geometry has a far greater effect on induction motor
performance than on that of synchronous motors. The cost of making the guideway is a
high percentage of the total investment for a maglev system. The comparison looks even
better for maglev when the terrain becomes difficult. Many of the tunnels, embankments,
and cuttings necessary for roads and railroads are avoided because maglev guideways can
be easily adapted to the topography. The Maglev system requires a slightly larger start-up
capital construction cost, its operating cost-- because it deploys electricity in
electromagnets in an extraordinarily efficient manner, rather than using as a fuel source
coal, gas or oil-- can be one-half that of conventional rail. The crucial point is that maglev
will set off a transportation and broader scientific explosion.
Key words: Magnetic levitation , Levitation , Propulsion , Linear induction motor(LIM).
3

19. Introduction:
Air flights are and will remain beyond the reach of a major section of society, particularly
in India. Moreover there are problems of wastage of time in air traffic delays and growing
safety concerns. Trends in increased mobility of large masses with changing lifestyle for
more comfort are leading to congestion on roads with automobiles. Besides, increasing
pollution levels from automobiles, depleting fuel resources, critical dependence on the
fuel import and due to a limited range of mobility of buses and cars the need for fast and
reliable transportation is increasing throughout the world. High-speed rail has been the
solution for many countries. Trains are fast, comfortable, and energy-efficient and
magnetic levitation may be an even better solution.
Development of magnetic levitated transport systems is under progress in developed
countries and it is just a matter of time they make inroads to India as well. Therefore, it
will be interesting to know about the science and technology behind mass ground
transport system known as "magnetic flight".
A LITTLE HISTORY
In 1922 a German engineer named Hermann Kemper recorded his first ideas for an
electromagnetic levitation train. He received a patent in 1934 and one year later
demonstrated the first functioning model. It wasn't until 1969, however, that a
government-sponsored research project built the first full scale functioning Transrapid 01.
The first passenger Maglev followed a few years later and carried people a few thousand
feet at speeds up to 50 mph. The company, Munich's KraussMaffei, which built the first
Transrapid, continued to build improved versions in a combined public-private research
effort and completed Transrapid 02 in 1971, TR 03 in 1972 and TR 04 in 1973. The
Transrapid 04 Transrapid 05 carried 50,000 visitors between parking and exhibition halls
for six months. A test center, including a 19-mile figure "eight" test track, was erected
between the years of 1979 and 1987 in North Germany. Going into service with the new
test facility in 1979 was the vehicle Transrapid 06. This vehicle reached a speed of
221mph shortly after the completion of the first 13-mile section of track. With the
completion of the track, the TR 06 eventually achieved a speed of 256 mph, traveling
some 40,000miles before being retired in 1990. Through the continuous testing and
refinements on the TR 06, it became possible to build the next generation vehicle
Transrapid 07, built by the Thyssen Co. in Kassel. Since 1989, the Transrapid 07 has been
the workhorse reaching the record speed of 280 mph and traveling some some 248,000
miles by the end of 1996.The most significant milestone was reached in 1991 when the
Transrapid system received its certification certification of commercial worthiness. 4

20. Principle Of Operation:
Imagine that two bar magnets are suspended one above the other with like poles (two
north poles or two south poles) directly above and below each other. Any effort to bring
these two magnets into contact with each other will have to overcome the force of
repulsion that exists between two like magnetic poles. The strength of that force of
repulsion depends, among other things, on the strength of the magnetic field between the
two bar magnets. The stronger the magnet field, the stronger the force of repulsion.
If one were to repeat this experiment using a very small, very light bar magnet as the
upper member of the pair, one could imagine that the force of repulsion would be
sufficient to hold the smaller magnet suspended—levitated—in air. This example
illustrates the principle that the force of repulsion between the two magnets is able to
keep the upper object suspended in air.
In fact, the force of repulsion between two bar magnets would be too small to produce the
effect described here. In actual experiments with magnetic levitation, the phenomenon is
produced by magnetic fields obtained from electromagnets. For example, imagine that a
metal ring is fitted loosely around a cylindrical metal core attached to an external source
of electrical current. When current flows through the core, it sets up a magnetic field
within the core. That magnetic field, in turn, sets up a current in the metal ring which
produces its own magnetic field. According to Lenz's law, the two magnetic fields thus
produced—one in the metal core and one in the metal ring—have opposing polarities.
The effect one observes in such an experiment is that the metal ring rises upward along
the metal core as the two parts of the system are repelled by each other. If the current is
increased to a sufficient level, the ring can actually be caused to fly upward off the core.
Alternatively, the current can be adjusted so that the ring can be held in suspension at any
given height with relation to the core.
MAGNETIC LEVIATION:
Magnetic levitation transport, or maglev, is a form of transportation that suspends, guides
and propels vehicles via electromagnetic force. This method can be faster and more
comfortable than wheeled mass transit systems. Maglevs could potentially reach
velocities comparable to turboprop and jet aircraft (500 to 580 km/h). Since much of a
Maglev's propulsion system is in the track rather than the vehicle, Maglev trains are
lighter and can ascend steeper slopes than conventional trains. They can be supported on
lightweight elevated tracks. Maglevs have operated commercially since 1984. However,
scientific and economic limitations have hindered the proliferation of the technology. 5

21. 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. In this
process an object is suspended above another with no other support but magnetic fields.
The electromagnetic force is used to counteract the effects of gravitation. . The forces
acting on an object in any combination of gravitational, electrostatic, and magnetostatic
fields will make the object's position unstable. The reason a permanent magnet suspended
above another magnet is unstable is because the levitated magnet will easily overturn and
the force will become attractive. If the levitated magnet is rotated, the gyroscopic forces
can prevent the magnet from overturning. Several possibilities exist to make levitation
viable.
It is possible to levitate superconductors and other diamagnetic materials, which
magnetize in the opposite sense to a magnetic field in which they are placed. A
superconductor is perfectly diamagnetic which means it expels a magnetic field
(Meissner-Ochsenfeld effect). Other diamagnetic materials are common place and can
also be levitated in a magnetic field if it is strong enough. Diamagnetism is a very weak
form of magnetism that is only exhibited in the presence of an external magnetic field.
The induced magnetic moment is very small and in a direction opposite to that of the
applied field. When placed between the poles of a strong electromagnet, diamagnetic
materials are attracted towards regions where the magnetic field is weak. Diamagnetism
can be used to levitate light pieces of pyrolytic graphite or bismuth above a moderately
strong permanent magnet. As Superconductors are perfect diamagnets and when placed in
an external magnetic field expel the field lines from their interiors (better than a
diamagnet). The magnet is held at a fixed distance from the superconductor or vice versa.
This is the principle in place behind EDS (electrodynamic suspension) maglev trains. The
EDS system relies on superconducting magnets.
A maglev is a train, which is suspended in air above the track, and propelled forward
using magnetism. Because of the lack of physical contact between the track and vehicle,
the only friction is that between the carriages and air. So maglev trains can travel at very
high speeds (650 km/h) with reasonable energy consumption and noise levels.
Due to the lack of physical contact between the track and the vehicle, the only friction
exerted is 6

22. that between the vehicles and the air. If it were the case that air-resistance were only a
minor form of friction, it would be appropriate to say "Consequently maglevs can
potentially travel at very high speeds with reasonable energy consumption and noise
levels. Systems have been proposed that operate at up to 650 km/h (404 mph), which is
far faster than is practical with conventional rail transport". But this is not true. In an
ordinary high speed train, most of the friction is air resistance. The power consumption
per passenger-km of the Transrapid Maglev train at 200 km/h is only 24% less than the
ICE at 200 km/h (22 W per seat-km, compared to 29 W per seat-km). The very high
maximum speed potential of maglevs make them competitors to airline routes of 1,000
kilometers (600 miles) or less
levitation
Each type of Maglev system requires propulsion as well as "levitation." The various
projects below use different techniques for propulsion. The first thing a maglev system
must do is get off the ground, and then stay suspended off the ground. This is achieved by
the electromagnetic levitation system.
Another experimental technology, which was designed, proven mathematically, peer
reviewed, and patented, but is yet to be built, is the magnetodynamic suspension (MDS),
which uses the attractive magnetic force of a permanent magnet array near a steel track to
lift the train and hold it in place. Other technologies such as repulsive permanent magnets
and superconducting magnets have seen some research.
Electromagnetic suspension:
In current electromagnetic suspension (EMS) systems, the train levitates above a steel rail
while electromagnets, attached to the train, are oriented toward the rail from below. The
system is typically arranged on a series of C-shaped arms, with the upper portion of the
arm attached to the vehicle, and the lower inside edge containing the magnets. The rail is
situated between the upper and lower edges.
Magnetic attraction varies with the cube of distance, so minor changes in distance
between the magnets and the rail produce greatly varying forces. These changes in force
are dynamically unstable - if there is a slight divergence from the optimum position, the
tendency will be to exacerbate this, and complex systems of feedback control are required
to maintain a train at a constant distance from the track, (approximately 15 millimeters
(0.6 in)).[21][22]
The major advantage to suspended maglev systems is that they work at all speeds, unlike
electrodynamic systems (see below) which only work at a minimum speed of about 30
km/h. This 7

23. eliminates the need for a separate low-speed suspension system, and can simplify the
track layout as a result. On the downside, the dynamic instability of the system demands
high tolerances of the track, which can offset, or eliminate this advantage. Laithwaite,
highly skeptical of the concept, was concerned that in order to make a track with the
required tolerances, the gap between the magnets and rail would have to be increased to
the point where the magnets would be unreasonably large.[20] In practice, this problem
was addressed through increased performance of the feedback systems, which allow the
system to run with close tolerances
The principal two systems: EMS- attractive and EDS-repulsive, respectively.
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. 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. The gap between the bottom of the vehicle and the rail
is only 3/8" and an electronic monitoring system, by controlling the amount of attractive
force, must closely control the size of the gap. 8

24. Electrodynamic suspension
EDS Maglev Propulsion via propulsion coils
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 (as in JR-Maglev) or by
an array of permanent magnets (as in Inductrack). The repulsive force in the track is
created by an induced magnetic field in wires or other conducting strips in the track. A
major advantage of the repulsive maglev systems is that they are naturally stable - minor
narrowing in distance between the track and the magnets create strong forces to repel the
magnets back to their original position, while a slight increase in distance greatly reduced
the force and again returns the vehicle to the right separation. No feedback control is
needed.
Repulsive systems have a major downside as well. 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 can sustain levitation. Since a train may stop
at any location, due to equipment problems for instance, the entire track must be able to
support both low-speed and high-speed operation. Another downside is that the repulsive
system naturally creates a field in the track in front and to the rear of the lift magnets,
which act against the magnets and create a form of drag. This is generally only a concern
at low speeds, at higher speeds the effect does not have time to build to its full potential
and other forms of drag dominate.
The drag force can be used to the electrodynamic system's advantage, however, as it
creates a varying force in the rails that can be used as a reactionary system to drive the
train, without the need for a separate reaction plate, as in most linear motor systems.
Laithwaite led development of such "traverse-flux" systems at his Imperial College lab
Alternately, propulsion coils on the guideway are used to exert a force on the magnets in
the train and make the train move forward. The propulsion coils that exert a force on the
train are effectively a linear motor: an alternating current flowing through the coils
generates a continuously varying magnetic field that moves forward along the track. 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 applied field creates a
force moving the train forward. 9

25. In the EDS-repulsive system, the superconducting magnets (SCMs), which do the
levitating of the vehicle, are at the bottom of the vehicle, but above the track. The track or
roadway is either an aluminum guideway or a set of conductive coils. The magnetic field
of the superconducting magnets aboard the maglev vehicle induces an eddy current in the
guideway. The polarity of the eddy current is same as the polarity of the SCMs onboard
the vehicle. Repulsion results, "pushing" the vehicle away and thus up from the track. The
gap between vehicle and guideway in the EDS-system is considerably wider, at 1 to 7
inches, and is also regulated (by a null-flux system). Thus, the guideway is not below, but
out to the sides. Now the repulsion goes perpendicularly outward from the vehicle to the
coils in the guidewalls. The perpendicular repulsion still provides lift.
they are all variations of the Linear Induction Motor (LIM) or Linear Synchronous Motor
(LSM).
Choice of linear electric motor
A linear electric motor (LEM) is a mechanism which converts electrical energy directly
into linear motion without employing any intervening rotary components. The
development of one type of LEM,
Linear synchronous motor (LSM), is illustrated in graphic form in Figure IV-1. A
conventional
rotary synchronous motor (above), such as that powering an electric clock, is made up of
two rings of alternating north and south magnetic poles. The outer ring (the stator) is
stationary, while the inner one (the rotor) is free to rotate about a shaft. The polarity of the
magnets on one (either) of these rings is fixed; this element is known as the field. The
magnets of the other ring, the armature, change their polarity in response to an applied
alternating current. Attractive forces between unlike magnetic poles pull each element of
the rotor toward the corresponding element of the stator. Just as the two poles are coming
into alignment, the polarity of the armature magnets is reversed, resulting in a repulsive
force that keeps the motor turning in the same direction. The armature poles are then
reversed again, and the motor turns at a constant speed in synchronism with the
alternating current 10

26. which causes the change in polarity
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. It is not a new technology but merely design in a different
form. Only the shape and the way it produces motion is changed. But there are
advantages: no moving parts, silent operation, reduced maintenance, compact size, ease
of control and installation. 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. Speed can be controlled by
either simple or complex systems. Stopping, starting, reversing, are all easy.
LEM's have long been regarded as the most promising means of propulsion for future
high-speed ground transportation systems. The proposed system, while not strictly
qualifying as high-speed, still derives so many advantages from the utilization of an LEM
that no other propulsion means is being considered at this stage.
Within the broad range of possible LEM designs, many alternatives are available. The
selection of the preferred configuration can perhaps best be understood through a
discussion of the choices considered and the reasons for the rejection of the others.
1. Synchronous vs. induction motors. Far more effort has been put into research and
development of linear induction motors (LIM's) than LSM's. LIM's do indeed have two
distinct advantages. First of all, they are simpler and less costly to construct. The
stationary element of the motor consists of nothing more than a rail or plate of a
conducting material, such as aluminum. Alternating current applied to the coils of the
moving electromagnets induces a fluctuating magnetic field around this conductor which
provides the propulsive force. By contrast, LSM's require the installation of alternating
north and south magnetic poles on both moving and stationary elements. Secondly, LIM's
are self-starting, with the speed of motion being infinitely variable from zero up to the
design maximum. LSM's, on the other hand, exhibit no starting torque; rotary motors of
this type are generally equipped with auxiliary squirrel-cage windings so that they can act
as induction motors until they reach operating speed.
LSM's possess other advantages, however, which are more than sufficient to outweigh
these faults. They are far more efficient; models have been built with efficiencies of 97%
or more, whereas the highest value yet attained for an LIM scarcely exceeds 70%. This is
true despite the fact that rotary synchronous motors enjoy only a slight efficiency
advantage over rotary induction motors; apparently the conversion to a linear geometry
has a far greater effect on induction motor performance than on that of synchronous
motors. Moreover, the efficiency of an LSM is relatively 11

27. unaffected by the speed of travel; LIM's, on the other hand, do not reach peak efficiencies
until they attain velocities which are well beyond those being considered here.
An LSM also operates at a constant speed, which depends solely on the frequency of the
alternating current applied to its armature. This feature offers opportunities for absolute
speed control; under normal operation, there is no way for any moving conveyance to
alter its prescribed position relative to that of any other vehicle on the track. This fact
imparts to any ground transportation system employing LSM's an enormously high traffic
capacity, many times greater than the maximum attainable using LIM's. The proposed
system demands such a capacity if it is to fulfill its goal of providing the opportunity for
individual travel from any point on the system to any other, and at any time, day or night.
Reciprocally, it is this potential for carrying huge volumes of traffic, made up of both
public and private vehicles and of both passengers and cargo, that can justify the extra
expenditure needed for the construction of an LSM-powered system.
Linear induction motor (LIM) in magnetic levitation
The High Speed Surface Transport (HSST) system is propelled by linear induction motor.
The HSST primary coils are attached to the carriage body and the track configuration is
simple, using the steel rails and aluminum reaction plates. The HSST levitation system
uses ordinary electromagnets that exerts an attractive force and levitate the vehicle. The
electro-magnets are attached to the car, but are positioned facing the under side of the
guide way's steel rails. They provide an attractive force from below, levitating the car.
This attractive force is controlled by a gap sensor that measures the distance between the
rails and electromagnets. A control circuit continually regulates the current to the electro-
magnet , ensuring that the gap remains at a fixed distance of about 8 mm, the current is
decreased. This action is computer controlled at 4000 times per second to ensure the
levitation.
As shown in figure, 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. The
use of an electro-magnetic attractive force to both levitate and guide the car is a
significant feature of HSST the system
We can visualize an HSST linear motor as an ordinary electric induction motor that has
been split open and flattened. This of linear motor has recently been used in various fields
the fig illustrates in the HSST, the primary side coils of motor are attached to the car body
in the secondary side reaction plates are installed along the guide way .this component
acts as induction motor and ensures both propulsion and breaking force without any
contact between car and guide way. This 12

28. system a car mounted primary linear induction system. The ground side requires only a
steel plate backed by an aluminum or copper plate, meaning that the rail source is simple.
One of the HSST's unique technical features is modules that correspond to the bogies on
connectional rolling stock. Figure shows each consist primarily of a member of
electromagnets for levitation guidance, a linear motor for propulsion and braking, and a
hydraulic break system.
The two modules on the left and right sides of the car connected beams and this unit is
called levitation bogie because the levitation bogies run the entire length of the car, the
load car and load on guide way are spread out and the advantages of magnetic levitation
can be fully exploited.
Characteristics of LIM
In most vehicular propulsion systems, provision must be made for increasing the power
when the demand increases due to acceleration, a heavier load, increased drag,
headwinds, or climbing a hill. In the case of an automobile, this is done through
manipulation of both the accelerator and the transmission. But all of this is accomplished
automatically when an LIM is used. Whenever more power is needed, the moving magnet
begins to lag further behind the stationary one; this results in an immediate increase in
thrust. No separate control is needed.
Moreover, when an LIM-powered vehicle descends a steep hill or decelerates into a station,
the moving motor advances to a position where it leads the stationary one. Under these
conditions, the motor performance is shown in the left half of Figure. This automatically
results in the production of electrical energy which is fed back into the system with a
frequency and phase coherent with the line voltage. In other words, LIM's are automatically
regenerative. 13

29. REQUIREMENTS OF AN URBAN MAGLEV
A thorough requirements document should be prepared during the initial stage of the
program. This document creates a common set of guidelines, which is intended to keep
the design team focused during the design/development process. Included are
requirements for the system and major subsystems to assure the performance, ride
comfort and safety of the passengers.
cost of propulsion coils could be prohibitive, a propeller or jet engine could be used.
Stability
Earnshaw's theorem shows that any combination of static magnets cannot be in a stable
equilibrium.[29] However, the various levitation systems achieve stable levitation by
violating the assumptions of Earnshaw's theorem. Earnshaw's theorem assumes that the
magnets are static and unchanging in field strength and that the relative permeability is
constant and greater than 1 everywhere. EMS systems rely on active electronic
stabilization. Such systems constantly measure the bearing distance and adjust the
electromagnet current accordingly. All EDS systems are moving systems (no EDS system
can levitate the train unless it is in motion).
Because Maglev vehicles essentially fly, stabilisation of pitch, roll and yaw is required by
magnetic technology. In addition translations, surge (forward and backward motions),
sway (sideways motion) or heave (up and down motions) can be problematic with some
technologies.
POWER AND ENERGY USAGE
Power for maglev trains is used to accelerate the train, and may be produced when the
train slowed ("regenerative braking"), it is also usually used to make the train fly, and to
stabilise the flight of the train, for air conditioning, heating, lighting and other
miscellaneous systems. Power is also needed to force the train through the air ("air drag").
14

30. At low speeds the levitation power can be significant, but at high speeds, the total time
spent levitating to travel each mile is greatly reduced, giving reduced energy use per mile,
but the air drag energy increases with the speed-squared, and hence at high speed
dominates.
Benefits of Magnetic Levitated Transportation system:
* Unlike conventional transportation systems in which a vehicle has to carry the total
power needed for the most demanding sections, the power of the maglev motor is
dependent on the local conditions such as flat or uphill grades.
* 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.
* Despite the speeds up to 500 km/hour, passengers can move about freely in the vehicles
at all times.
* Maglev vehicle carries no fuel to increase fire hazard
* The materials used to construct maglev vehicles are non-combustible, poor transmitters
of heat, and able to withstand fire penetration.
* In the unlikely event that a fire and power loss occurred simultaneously, the vehicle is
automatically slowed down so that it stops at a predefined emergency power station.
* A collision between two maglev trains is nearly impossible because the linear induction
motors prevent trains running in opposite directions or different speeds within the same
power section.
Current Projects:
Germany and Japan have been the pioneering countries in MagLev research. Currently
operational systems include Transrapid (Germany) and High Speed Surface Transport
(Japan). There are several other projects under scrutiny such as the SwissMetro, Seraphim
and Inductrack. All have to do with personal rapid transit.
Other Applications:
NASA plans to use magnetic levitation for launching of space vehicles into low earth
orbit. Boeing 15

31. 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
Boones and Banes:
BOONS:
Maintenance: Because the train floats along there is no contact with the ground and
therefore no need for any moving parts. As a result there are no components that would
wear out. This means in theory trains and track would need no maintenance at all.
Friction: Because maglev trains float, there is no friction. Note that there will still be air
resistance
Less noise: because there are no wheels running along there is no wheel noise. However
noise due to air disturbance still occurs.
Speed: As a result of the three previous listed it is more viable for maglev trains to travel
extremely fast, i.e. 500km/h or 300mph
BANES:
1. Maglev guide paths are bound to be more costly than conventional steel railways.
2. The other main disadvantage is lack with existing infrastructure. For example if a high
speed line between two cities it built, then high speed trains can serve both cities but more
importantly they can serve other nearby cities by running on normal railways that branch
off the high speed line. The high speed trains could go for a fast run on the high speed
line, and then come off it for the rest of the journey. Maglev trains wouldn't be able to do
that; they would be limited to where maglev lines run. This would mean it would be very
difficult to make construction of maglev lines commercially viable unless there were two
very large destinations being connected. The fact that a maglev train will not be able to
continue beyond its track may seriously hinder its usefulness.
. 16

32. COMPARISION:
Compared to conventional trains
Major comparative differences between the two technologies lie in backward-
compatibility, rolling resistance, weight, noise, design constraints, and control systems.
Backwards Compatibility Maglev trains currently in operation are not compatible with
conventional track, and therefore require all new infrastructure for their entire route. By
contrast conventional high speed trains such as the TGV are able to run at reduced speeds
on existing rail infrastructure, thus reducing expenditure where new infrastructure would
be particularly expensive (such as the final approaches to city terminals), or on extensions
where traffic does not justify new infrastructure.
Efficiency Due to the lack of physical contact between the track and the vehicle, maglev
trains experience no rolling resistance, leaving only air resistance and electromagnetic
drag, potentially improving power efficiency.[32]
Weight The weight of the large electromagnets in many EMS and EDS designs is a major
design issue. A very strong magnetic field is required to levitate a massive train. For this
reason one research path is using superconductors to improve the efficiency of the
electromagnets, and the energy cost of maintaining the field.
Noise. Because the major source of noise of a maglev train comes from displaced air,
maglev trains produce less noise than a conventional train at equivalent speeds. However,
the psychoacoustic profile of the maglev may reduce this benefit: A study concluded that
maglev noise should be rated like road traffic while conventional trains have a 5-10 dB
"bonus" as they are found less annoying at the same loudness level.[33][34]
Design Comparisons Braking and overhead wire wear have caused problems for the
Fastech 360 railed Shinkansen. Maglev would eliminate these issues. Magnet reliability at
higher temperatures is a countervailing comparative disadvantage (see suspension types),
but new alloys and manufacturing techniques have resulted in magnets that maintain their
levitational force at higher temperatures.
As with many technologies, advances in linear motor design have addressed the
limitations noted in early maglev systems. As linear motors must fit within or straddle
their track over the full length of the train, track design for some EDS and EMS maglev
systems is challenging for anything other than point-to-point services. Curves must be
gentle, while switches are very long and need care to avoid breaks in current. An SPM
maglev system, in which the vehicle permanently levitated over 17

33. the tracks, can instantaneously switch tracks using electronic controls, with no moving
parts in the track. A prototype SPM maglev train has also navigated curves with radius
equal to the length of the train itself, which indciates that a full-scale train should be able
to navigate curves with the same or narrower radius as a conventional train.
Control Systems EMS Maglev needs very fast-responding control systems to maintain a
stable height above the track; this needs careful design in the event of a failure in order to
avoid crashing into the track during a power fluctuation. Other maglev systems do not
necessarily have this problem. For example, SPM maglev systems have a stable levitation
gap of several centimeters.
Compared to aircraft
For many systems, it is possible to define a lift-to-drag ratio. For maglev systems these
ratios can exceed that of aircraft (for example Inductrack can approach 200:1 at high
speed, far higher than any aircraft). This can make maglev more efficient per kilometre.
However, at high cruising speeds, aerodynamic drag is much larger than lift-induced
drag. Jet transport aircraft take advantage of low air density at high altitudes to
significantly reduce drag during cruise, hence despite their lift-to-drag ratio disadvantage,
they can travel more efficiently at high speeds than maglev trains that operate at sea level
(this has been proposed to be fixed by the vactrain concept). Aircraft are also more
flexible and can service more destinations with provision of suitable airport facilities.
Unlike airplanes, maglev trains are powered by electricity and thus need not carry fuel.
Aircraft fuel is a significant danger during takeoff and landing accidents. Also, electric
trains emit little carbon dioxide emissions, especially when powered by nuclear or
renewable sources. 18

34. 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: 1. Non-
contact and non-wearing propulsion, independent of friction, no mechanical components
like wheel, axle. Maintenance costs decrease. Low noise emission and vibrations at all
speeds(again due to non-contact nature). Low specific energy consumption. Faster
turnaround times, which means fewer vehicles. All in all, low operating costs. Speeds of
up to 500kmph.. Low pollutant emissions. Hence environmentally friendly.
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.