Page | 1 MAGNETIC LEVITATION TRAIN A Seminar Report Submitted in the partial fulfillment of the requirement for the award of the degree of Bachelor of Technology In “ELECTRICAL ENGINEERING” By Anuj bansal (Reg. no. 12208, roll no. 1204220007) Supervisor Mr. Kishan Bhushan Sahay Submitted in Department of Electrical Engineering MADAN MOHAN MALAVIYA UNIVERSITY OF TECHNOLOGY GORAKHPUR-273010
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MAGNETIC LEVITATION TRAIN
A
Seminar Report
Submitted in the partial fulfillment of the requirement for the award
of the degree of
Bachelor of Technology
In
“ELECTRICAL ENGINEERING”
By
Anuj bansal
(Reg. no. 12208, roll no. 1204220007)
Supervisor
Mr. Kishan Bhushan Sahay
Submitted in
Department of Electrical Engineering
MADAN MOHAN MALAVIYA UNIVERSITY OF TECHNOLOGY
GORAKHPUR-273010
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Department of Electrical Engineering
MADAN MOHAN MALAVIYA UNIVERSITY OF TECHNOLOGY, Gorakhpur-273010
CERTIFICATE
This is to certify that the report work entitled “MAGNETIC LEVITATION TRAIN”
submitted in partial fulfillment of the requirement for the degree of Bachelor of Technology in
“ELECTRICAL ENGINEERING”, is a bonafide seminar work carried out by Mr. ANUJ
BANSAL under my supervision and guidance.
Date: _________ Mr. Kishan Bhushan Sahay
Electrical Engineering Department
M.M.M.U.T, Gorakhpur
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CONTENT
Certificate i
Acknowledgement ii
Abstract iii
List of Figure IV
1. Introduction 1-5
1.1 Introduction 1
1.2 Technology of Magnetic Levitation 2
1.3 Types of Magnetic Levitation 3-5
1.3.1 Permanent magnet type 3
1.3.2 Electromagnetic type 4
1.3.3 Electrodynamics type 5
2. Working Principle 6-9
2.1 Levitation 6
2.2 Propulsion 7
2.3 Stability 8
2.4 Guidance 9
3. Evacuated Tube and Energy Source 10-11
3.1 Evacuated tube 10
3.2 Energy source 11
4. Comparison with AIRCRAFT AND CONVENTIONAL TRAINS 12-14
5. Economics 15
6. Merits and Demerits 16
7. Existing Maglev System 17-18
Summary and conclusion 19
References 20
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Acknowledgement
Every pseminar big or small is successful largely due to the effort of a number of wonderful
people who have always given their valuable advice or lent a helping hand. I sincerely appreciate
the inspiration; support and guidance of all those people who have been instrumental in making
this project a success.
I wish to express sense of gratitude to my guide to Mr. Kishan Bhushan Sahay, Electrical
Engineering Department. Madan Mohan Malaviya University of Technology, Gorakhpur, to give
me guidance at every moment during my entire thesis and giving valuable suggestions. He gives
me unfailing inspiration and whole hearted co-operation in caring out my seminar work. His
continuous encouragement at each of work and effort to push the work through are grateful
acknowledged.
I am also very grateful to my classmates, MMMUT, Gorakhpur for their huge co-operation and
valuable suggestion from time to time during my entire seminar work. I also extend my gratitude
to all members of the department without whose support at various stages this report will not be
materialized.
Last but not the least I wish to thanks my friends of B. Tech. 6th semester and seniors who helped
me directly or indirectly in the successful completion of this work.
Date: ____________ ANUJ BANSAL
Place: ____________
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ABSTRACT
Magnetic Levitation is a technology that has been experimented with intensely over the past
couple decades. It wasn’t until the last ten years when scientists began to develop systems that
would use magnetic levitation as a means of transport. This paper outlines the methods behind
magnetic levitation, as well as the technologies implemented using the levitation. The
implementation of a large-scale transportation system using magnetic levitation has huge social
as well as economical effects. These aspects are looked at in a number of situations to see if the
effort in producing a system using magnets is worth the time and eff.
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-: LIST OF FIGURE:-
Figure No.-
1. Permanent magnets
2. Electromagnetic magnets
3. Electrodynamics magnets
4. Levitation process
5. Propulsion process
6. Stability process
7. Guidance process
8. Evacuated Tubes
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CHAPTER 1:- INTRODUCTION
Some forces in this world are almost invisible to the naked eye and most people
throughout the world do not even know they exist. On one side you could say that some
of these forces are abstract feelings inside of a human being that have been given names
from man. These forces could be things like emotion, guilt, and even ecstasy. On the
other side you have solid concrete principles of how the world works. These too have
been given names by man, but these principles are not abstract and have solid ground in
science. These different principles are things like gravity, electricity, and magnetism.
Magnetism has been a part of the earth since the beginning whether people realize it or
not. It is due to the magnetism of the earth that the world spins and thus creates things
like gravity. The magnetism is created by the processes within the core of the earth. The
earth’s iron-ore core has a natural spinning motion to it inside which creates a natural
magnetic force that is held constant over the earth. This creates magnetic forces that turn
the earth into a large bar magnet. The creation of North and South poles on the earth are
due to this field.
From this magnetic field, we see things such as the aurora borealis. This is a small
electromagnetic storm in the atmosphere which creates a display for all to see. Not only
does magnetism provide us with amazing natural displays, but it also provides for us
amazing applications to society. One of these applications is magnetic levitation.
Magnetic levitation uses the concept of a magnets natural repulsion to poles of the same
kind. This repulsion has been harnessed and controlled in an environment to help create
a system of transportation that is both economically sound and faster than most methods
of transportation at this point.
In 1965 the Department of Commerce established the High Speed Ground
Transportation Act. Most early work on developing Maglev technology was developed
during this time. The earliest work was carried out by the Brookhaven National
Laboratory, Massachusetts Institute of Technology, Ford, Stanford Research Institute,
Rohr Industries, Boeing Aerospace Co., and the Garrett Corporation. In the United
States, though, the work ended in 1975 with the termination of Federal Funding for high-
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speed ground transportation and research. It was at that time when the Japanese and
German developers continued their research and therefore came out with the first test
tracks.
In 1990, legislative action directed the U.S. Army Corps of Engineers to
implement and prepare a plan for a National Maglev program. The Department of
Transportation (DOT), Department of Energy (DOE), and the Army Corp developed
what is known as the National Maglev Initiative which was a two year 25 million dollar
program to assess the engineering, economic, environmental and safety aspects of
Maglev.
1.1:- TECHNOLOGY OF MAGLEV TRAIN
The creation of magnetic forces is the basis of all magnetic levitation. The creation of a
magnetic field can be caused by a number of things. The first thing that it can be caused by is a
permanent magnet. These magnets are a solid material in which there is an induced North and
South Pole. These will be described further a little later. The second way that a magnetic field
can be created is through an electric field changing linearly with time. The third and final way to
create a magnetic field is through the use of direct current.
There are two basic principles in dealing with the concept of magnetic levitation. The first law
that is applied was created by Michael Faraday. This is commonly known as Faraday’s Law.
This will allow the direction of the magnetic field to be predictable and thus a set up can be
created for a specific purpose to maximize the force that is created.
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1.2:-TYPES OF MAGNETIC LEVITATION
1.2.1) Permanent Magnets:-
The first type of levitation is the implementation through permanent magnets. These
magnets are made of a material that creates a north and a south pole on them.
The formal definition of a permanent magnet is “a material that retains its magnetic
properties after and external magnetic field is removed.”i The whole idea behind
permanent magnets is that like ends will repel and opposite ends will attract. Permanent
magnets require very little if any maintenance. These magnets do not require cryogens or
a large power supply for operation. The magnetic field is measured vertically within the
bore of the magnet. The main disadvantages of a permanent magnet are the cost of the
magnet itself when put into large scale systems. Another disadvantage is the varying
changes in the magnetic field. The ability to control a constant magnetic force from a
permanent magnet is an on-going problem in the application of these types of magnets. .
Different applications that use these types of magnets can be found in a number of
different areas. Examples of these applications are compasses, DC motor drives, clocks,
hearing aids, microphones, speedometers, and many more.
Figure 1:Permanent magnet
1.2.2 Electromagnetic type:-
The basic idea behind an electromagnet is extremely simple. By running electric
current through a wire, you can create a magnetic field. When this wire is coiled around
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a magnetic material (i.e. metal), a current is passed through this wire. In doing this, the
electric current will magnetize the metallic core. By using this simple principle, you can
create all sorts of things including motors, solenoids, heads for hard disks, speakers, and
so on. An electromagnet is one that uses the same type of principles as the permanent
magnet but only on a temporary scale. This means that only when the current is flowing
is there going to be an induced magnet. This type of magnet is an improvement to the
permanent magnet because it allows somebody to select when and for how long the
magnetic field lasts. It also gives a person control over how strong the magnet will be
depending on the amount of current that is passed through the wire.
Figure 2 Electromagnetic magnets
1.2.3 Electrodynamics type:-
The ideas presented behind superconductive magnets are the same principles that are at
work in an MRI. Superconductive magnets are the most common of all the magnets, and are
sometimes called cry magnets. The idea behind the superconducting magnets is that there is a
material which presents no electrical resistivity to electrical current. Once a current has been fed
into the coils of this material, it will indefinitely flow without requiring the input of any
additional current. The way that a material is able to have such a low resistivity to current is that
it is brought to very low temperatures. The temperatures that are commonly found in
superconducting magnets are around -258oC. This is done by immersing the coils that are
holding the current into liquid Helium; this also helps in maintaining a homogenous magnetic
field over time. The advantage to the superconducting magnet is that they don’t require constant
power from a source to keep up the value of the current in the coils. Although a disadvantage is
that they require an expensive cryogen such as helium to operate correctly. The magnetic field is
in the direction of the long axis of the cylinder or bore of the magnet. Since the resistance in the
coils can cause the current to decay, cryogens reduce the resistance to almost zero, which will
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help maintain a homogenous magnetic field over time.
Figure 3 Electrodynamics magnet
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CHAPTER2:- WORKING PRINCIPLE
2.1 Levitation:-
Support electromagnets built into the undercarriage and along the entire length of the
train pull it up to the guide way electromagnets, which are called ferromagnetic reaction rails.
The guidance magnets placed on each side of the train keep it centred along the track and guide
the train along. All the electromagnets are controlled electronically in a precise manner. It
ensures the train is always levitated at a distance of 8 to 10 mm from the guide way even when it
isn't moving. This levitation system is powered by on-board batteries, which are charged up by
the linear generator when the train travels. The generator consists of additional cable windings
integrated in the levitation electromagnets. The induced current of the generator during driving
uses the
Propulsion magnetic field's harmonic waves, which are due to the side effects of the grooves of
the long stator so the charging up process does not consume the useful propulsion magnetic field.
The train can rely on this battery power for up to one hour without an external power source. The
levitation system is independent from the propulsion system.
Figure 4: Levitation
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2.2 Propulsion:-
The synchronous long stator linear motor of the Maglev system is used both for
propulsion and braking. It is functioning like a rotating electric motor whose stator is cut open
and stretched along under the guide way. Inside the motor windings, alternating current is
generating a magnetic traveling field which moves the vehicle without contact. The support
magnets in the vehicle function as the excitation portion (rotor).
Propulsion system in the guide way is activated only in the section where the vehicle actually
runs. The speed can be continuously regulated by varying the frequency of the alternating
current. If the direction of the traveling field is reversed, the motor becomes a generator which
breaks the vehicle without any contact. The braking energy can be re-used and fed back into the
electrical network. The three-phase winded stator generates an electromagnetic travelling field
and moves the train when it is supplied with an alternating current. The electromagnetic field
from the support electromagnets (rotor) pulls it along. The magnetic field direction and speed of
the stator and the rotor are synchronized. The Maglev's speed can vary from standstill to full
operating speed by simply adjusting the frequency of the alternating current. To bring the train to
a full stop, the direction of the travelling field is reversed. Even during braking, there isn't any
mechanical contact between the stator and the rotor. Instead of consuming energy, the Maglev
system acts as a generator, converting the breaking energy into electricity, which can be used
elsewhere.
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Figure 5:Propulsion
2.3 Stability:-
For successful levitation and control of all 6 axes (degrees of freedom; 3 translational and 3
rotational) a combination of permanent magnets and electromagnets or diamagnets or superconductors as
well as attractive and repulsive fields can be used. From Earns haw’s theorem at least one stable axis must
be present for the system to levitate successfully, but the other axes can be stabilized using
ferromagnetism. Static stability means that any small displacement away from a stable equilibrium causes
a net force to push it back to the equilibrium point. Earns haw’s theorem proved conclusively that it is not
possible to levitate stably using only static, macroscopic, paramagnetic fields. The forces acting on any
paramagnetic object in any combinations of gravitational, electrostatic, and magneto static fields will
make the object's position, at best, unstable along at least one axis, and it can be unstable equilibrium
along all axes. However, several possibilities exist to make levitation viable, for example, the use of
electronic stabilization or diamagnetic materials (since relative magnetic permeability is less than one); it
can be shown that diamagnetic materials are stable along at least one axis, and can be stable along all
axes. Conductors can have a relative permeability to alternating magnetic fields of below one, so some
configurations using simple AC driven electromagnets are self-stable. Dynamic stability occurs when the
levitation system is able to damp out any vibration-like motion that may occur.
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Magnetic fields are conservative forces and therefore in principle have no built-in damping, and in
practice many of the levitation schemes are under-damped and in some cases negatively damped.[4] This
can permit vibration modes to exist that can cause the item to leave the stable region.
Figure 6 :Stability
2.4 Guidance:-
Electronically controlled support magnets located on both sides along the entire length of
the vehicle pull the vehicle up to the ferromagnetic stator packs mounted to the underside of the
guide way. Guidance magnets located on both sides along the entire length of the vehicle keep
the vehicle laterally on the track. Electronic systems guarantee that the clearance remains
constant (nominally 10 mm). To hover, the Maglev requires less power than its air conditioning
equipment. The levitation system is supplied from on-board batteries and thus independent of the
propulsion system. The vehicle is capable of hovering up to one hour without external energy.
While travelling, the on-board batteries are recharged by linear generators integrated into the
support magnets.
The Maglev hovers over a double track guide way. It can be mounted either at grade or elevated
on slim columns and consists of individual steel or concrete beams up to 62 m in length.
Guidance or steering refers to the sideward forces that are required to make the vehicle follow
the guide way. The necessary forces are supplied in an exactly analogous fashion to the
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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.
They use Null Flux systems, also known as Null Current systems, this use a coil which is wound
so that it enters two opposing, alternating fields. When the vehicle is in the straight ahead
position, no current flows, but if it moves off-line this creates a changing flux that generates a
field that pushes it back into line.
Figure 7: Guidance
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CHAPTER3:-EVACUATED TUBE AND ENERGY SOURCE
3.1 Evacuated Tube
Some systems (notably the Swiss metro system) propose the use of Victorians—maglev
train technology used in evacuated (airless) tubes, which removes air drag. This has the potential
to increase speed and efficiency greatly, as most of the energy for conventional maglev trains is
lost to aerodynamic drag.
One potential risk for passengers of trains operating in evacuated tubes is that they could
be exposed to the risk of cabin depressurization unless tunnel safety monitoring systems can
depressurize the tube in the event of a train malfunction or accident though since trains are likely
to operate at or near the Earth's surface, emergency restoration of ambient pressure should be
straightforward. The RAND Corporation has depicted a vacuum tube train that could, in theory,