magnetic on final report

8/14/2019 Magnetic on Final Report

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INTRODUCTION

Ma gn et ic l ev it at io n , maglev , ormag ne t ic s usp ens io n is a method by which anobject is suspended with no support other than magnetic fields. The electromagnetic force is

used to counteract the effects of the gravitationalforce.

Earnshaw's theorem proves that using only static

ferromagnetism it is impossible to stably levitate

against gravityas required for stable equilibrium.

Earnshaw's theorem can be viewed as a

consequence of the Maxwell equations, which

do not allow the magnitude of a magnetic field in a

free space to possess a maximum. Butservomechanisms, the use of diamagnetic materials or superconductor permit this to occur.

For a particle to be in a stable equilibrium, small perturbations ("pushes") on the particle in

any direction should not break the equilibrium; the particle should "fall back" to its previous

position. This means that the force field lines around the particle's equilibrium position

should all point inwards, towards that position. If all of the surrounding field lines point

towards the equilibrium point, then the divergence of the field at that point must be negative

(i.e. that point acts as a sink). However, Gauss's Law says that the divergence of any

possible electric force field is zero in free space.Diamagnets (which respond to magneticfields with mild repulsion) are known to flout the theorem, as their negative susceptibility

results in the requirement of a minimum rather than a maximum in the fields magnitude.

Stable levitation has been demonstrated for diamagnetic objects such as superconducting

pellets and live creatures. Strong diamagnetism of superconductors allows the situation to

be reversed, so that a magnet can be levitated above a superconductor.

We set out to lift a magnet by applying a magnetic field and then stabilizing the intrinsically

unstable equilibrium with repulsive forces from a nearby diamagnetic material. Diamagnetic

levitation can be used to levitate very light pieces ofpyrolytic graphite orbismuth above amoderately strong permanent magnet. As wateris predominantly diamagnetic, this

technique has been used to levitate water droplets and even live animals, such as a

grasshopper and a frog. However, the magnetic fields required for this are very high,

typically in the range of 16 teslas, and therefore create significant problems ifferromagnetic

materials are nearby.

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MAGLEV METHODS

There are several methods to obtain magnetic levitation. The following are a few general

methods.

Me ch an ic al co nstr ai nt (P se ud o-le vi ta ti on )With a small amount of mechanical constraint for stability, pseudo-levitation is relatively

straightforwardly achieved.

If two magnets are mechanically constrained along a single vertical axis, for example, and

arranged to repel each other strongly, this will act to levitate one of the magnets above the

other.

Another geometry is where the magnets are attracted, but constrained from touching by a

tensile member, such as a string or cable.

Another example is the Zippe-type centrifuge where a cylinder is suspended under an

attractive magnet, and stabilised by a needle bearing from below.

Dir ect d iam ag ne t ic l evi ta ti on

A live frog levitates inside a 32 mmdiametervertical bore of

a Bitter solenoid in a magnetic field of about 16 teslas at the

High Field Magnet Laboratory of the Radboud University in

Nijmegen the Netherlands.

A substance that is diamagneticrepels a magnetic field. All materials have diamagnetic

properties, but the effect is very weak, and is usually overcome by the object'sparamagnetic orferromagneticproperties, which act in the opposite manner. Any material in

which the diamagnetic component is strongest will be repelled by a magnet, though this

force is not usually very large.

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Earnshaw's theorem does not apply to diamagnets. These behave in the opposite manner

to normal magnets owing to their relative permeability of r < 1 (i.e. negative magnetic

susceptibility).

Diamagnetic levitation can be used to levitate very light pieces ofpyrolytic graphite orbismuth above a moderately strong permanent magnet. As wateris predominantly

diamagnetic, this technique has been used to levitate water droplets and even live animals,

such as a grasshopper and a frog. However, the magnetic fields required for this are very

high, typically in the range of 16 teslas, and therefore create significant problems if

ferromagnetic materials are nearby.

The minimum criterion for diamagnetic levitation is , where:

is the magnetic susceptibility

is the density of the material

gis the local gravitational acceleration (-9.8 m/s2 on Earth)

0 is the permeability of free space

Bis the magnetic field

is the rate of change of the magnetic field along the vertical axis

Assuming ideal conditions along the z-direction of solenoid magnet:

Waterlevitates at

Graphite levitates at

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Su pe rco nd uct orsSuperconductors may be considered pe rf ect d iam ag ne ts (r = 0), completely expellingmagnetic fields due to the Meissner effect. The levitation of the magnet is stabilized due to

flux pinning within the superconductor. This principle is exploited by EDS (electrodynamic

suspension) magnetic levitation trains, superconducting bearings, flywheels, etc.

In trains where the weight of the large electromagnet is a major design issue (a very strong

magnetic field is required to levitate a massive train) superconductors are sometimes

proposed for use for the electromagnet, since they can produce a stronger magnetic field for

the same weight.

Dia ma gn et ic al ly -sta bi l iz ed levi ta ti onA permanent magnet can be stably suspended by various configurations of strong

permanent magnets and strong diamagnets. When using superconducting magnets, the

levitation of a permanent magnet can even be stabilized by the small diamagnetism of water

in human fingers.

Ro ta ti on al sta bi l iz at io nA magnet can be levitated against gravity when gyroscopically stabilized by spinning it in a

toroidal field created by a base ring of magnet(s). However, it will only remain stable until the

rate ofprecession slows below a criticalthreshold the region of stability is quite narrow

both spatially and in the required rate of precession. The first discovery of this phenomenon

was by Roy Harrigan, a Vermont inventor who patented a levitation device in 1983 basedupon it. Several devices using rotational stabilization (such as the popularLevitrontoy) have

been developed citing this patent. Non-commercial devices have been created for university

research laboratories, generally using magnets too powerful for safe public interaction.

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Se rvo me ch an ismsThe attraction from a fixed strength magnet decreases with increased distance, and

increases at closer distances. This is termed 'unstable'. For a stable system, the opposite is

needed; variations from a stable position should push it back to the target position.

Stable magnetic levitation can be achieved by measuring the position and speed of the

object being levitated, and using afeedback loop which continuously adjusts one or more

electromagnets to correct the object's motion, thus forming a servomechanism.

Many systems use magnetic attraction pulling upwards against gravity for these kinds of

systems as this gives some inherent lateral stability, but some use a combination ofmagnetic attraction and magnetic repulsion to push upwards.

This is termed Electromagnetic suspension (EMS). For a very simple example, some

tabletop levitation demonstrations use this principle, and the object cuts a beam of light to

measure the position of the object. The electromagnet is above the object being levitated;

the electromagnet is turned off whenever the object gets too close, and turned back on

when it falls further away. Such a simple system is not very robust; far more effective control

systems exist, but this illustrates the basic idea. A practical demonstration of such system

can be seenhere. Of course in the real situation the problem becomes much more complex

while the requirements of a MAGLEV suspension are difficult to achieve, i.e the

electromagnetic suspension has to support very large mass (for axample 1T) wihtin a small

air gap (in the region of mm). Also, the EMS system has to accomodate the rail

irregulatrities while follow the track gradients. Nevertheless, all these requirements can be

achieved using advance control strategies. A practical demonstration of a 25kg Electro-

magnetic suspension setup is shown here. The Electromagnets are suspending 5mm below

the track (rail). The control can be done using classical strategies as shown here or modern

control strategies as shown here.

EMS magnetic levitation trainsare based on this kind of levitation: The train wraps around

the track, and is pulled upwards from below. The servo controls keep it safely at a constant

distance from the track.

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In du ce d cur re nts/ Ed dy c urre ntsThis is sometimes called ElectroDynamic Suspension (EDS).

Re lat iv e m ot ion be tw ee n conduct ors an d magne tsIf one moves a base made of a very good electrical conductor such as copper, aluminium or

silverclose to a magnet, an (eddy) current will be induced in the conductor that will oppose

the changes in the field and create an opposite field that will repel the magnet (Lenz's law).

At a sufficiently high rate of movement, a suspended magnet will levitate on the metal, or

vice versa with suspended metal. Litz wire made of wire thinner than the skin depth for the

frequencies seen by the metal works much more efficiently than solid conductors.

An especially technologically-interesting case of this comes when one uses a Halbach array

instead of a single pole permanent magnet, as this almost doubles the field strength, which

in turn almost doubles the strength of the eddy currents. The net effect is to more than triple

the lift force. Using two opposed Halbach arrays increases the field even further.[3]

Halbach arrays are also well-suited to magnetic levitation and stabilisation ofgyroscopes

and electric motorand generatorspindles.

Osci l la ti ng e lectr om ag ne ti c f ie ldsA conductorcan be levitated above an electromagnet (or vice versa) with an alternating

current flowing through it. This causes any regular conductor to behave like a diamagnet,

due to the eddy currents generated in the conductor. Since the eddy currents create their

own fields which oppose the magnetic field, the conductive object is repelled from the

electromagnet.

This effect requires non-ferromagnetic but highly conductive materials like aluminium or

copper, as the ferromagnetic ones are also strongly attracted to the electromagnet

(although at high frequencies the field can still be expelled) and tend to have a higher

resistivity giving lower eddy currents. Again, litz wire gives the best results.

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The effect can be used for stunts such as levitating a telephone book by concealing an

aluminium plate within it.

St ab i l iz ed pe rm an en t m ag ne t sus pe nsi onIn this method a repulsive magnet arrangement is used to provide lift and then any one or

combination of the above stabilisation systems are used laterally. The vertical component of

the lift magnets is stable in this arrangement, whereas the horizontal component is unstable,

but, (depending on the geometry) rather smaller, and hence somewhat easier to stabilise.

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Application in MEGLAV VEHICLE

The main application of meglav is in meglav vehicle so while discussing magnetic levitationit is a must to discuss the technology used in meglav vehicle. The term "maglev" refers not

only to the vehicles, but to the railway system as well, specifically designed for magnetic

levitation and propulsion. All operational implementations of maglev technology have had

minimal overlap with wheeled train technology and have not been compatible with

conventional rail tracks. Because they cannot share existing infrastructure, these maglev

systems must be designed as complete transportation systems.

Basically the there are three main forces involved in working of a meglav vehicle. All the

forces work for one goal to stably levitate a considerable mass while making it move fromone place to another.

LEVITATION.

PROPULSION.

LATERAL GUIDING

LE V IT A TIO NThe levitating force is the upward thrust which lifts the vehicle in the air. It counteracts the

gravitational force and make the body float in air.

There are 3 types of levitating systems.

Forelectromagnetic suspension (EMS), electromagnets in the train repel it away

from a magnetically conductive (usually steel) track.

electrodynamic suspension (EDS) uses electromagnets on both track and train to

push the train away from the rail. stabilized permanent magnet suspension (SPM) uses opposing arrays of permanent

magnets to levitate the train above the rail.

Another experimental technology, which was designed, proven mathematically, peer

reviewed, and patented, but is yet to be built, is the magnetodynamic suspension(MDS),

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which uses the attractive magnetic force of a permanent magnet array near a steel track to

lift the train and hold it in place.

ELECTROMAGNETIC SUSPENSION (EMS)

The attraction from a fixed strength magnet decreases with increased distance, and

increases at closer distances. This is termed 'unstable'. For a stable system, the opposite is

needed; variations from a stable position should push it back to the target position.

Stable magnetic levitation can be

achieved by measuring the position and

speed of the object being levitated, and

using a feedback loop which

continuously adjusts one or moreelectromagnets to correct the object's

motion, thus forming a

servomechanism.

Many systems use magnetic attraction

pulling upwards against gravity for

these kinds of systems as this gives

some inherent lateral stability, but some use a combination of magnetic attraction and

magnetic repulsion to push upwards.

This is termed Electromagnetic suspension (EMS). For a very simple example, some

tabletop levitation demonstrations use this principle, and the object cuts a beam of light to

measure the position of the object. The electromagnet is above the object being levitated;

the electromagnet is turned off whenever the object gets too close, and turned back on

when it falls further away. Such a simple system is not very robust; far more effective control

systems exist, but this illustrates the basic idea. Of course in the real situation the problem

becomes much more complex while the requirements of a MAGLEV suspension are difficultto achieve, i.e the electromagnetic suspension has to support very large mass (for example

1T) wihtin a small air gap (in the region of mm). Also, the EMS system has to accomodate

the rail irregulatrities while follow the track gradients. Nevertheless, all these requirements

can be achieved using advance control strategies. EMS magnetic levitation trains are based

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on this kind of levitation: The train wraps around the track, and is pulled upwards from

below. The servo controls keep it safely at a constant distance from the track.

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Ele ctr ody na mi c sus pe nsi onIn 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.

At slow speeds, the current induced in

these coils and the resultant magneticflux 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.

Onboard magnets and large margin between rail and train enable highest recorded train

speeds (581 km/h).This system is inherently stable. Magnetic shielding for suppression of

strong magnetic fields and wheels for travel at low speed are required. It cant produce the

propulsion force. So, LIM system is required.

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Fig. 9 The guideway of the electrodynamic suspensionsystem is installed with guidance-levitation coils.
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St ab i l iz ed Pe rm an en t Ma gn et sus pe nsi onSPM maglev systems differ from EDS maglev in that they use opposing sets ofrare earth

magnets (typically neodymium alloys in a Halbach array) in the track and vehicle to create

permanent, passive levitation; i.e., no power is required to maintain permanent levitation.

With no current required for levitation, the system has much less electromagnetic drag, thus

requiring much less power to move a given cargo at a given speed.

Because ofEarnshaw's theorem, SPM maglev systems require a mechanism to createlateral stability (i.e., controlling the side-to-side movement of the vehicle). One way to

provide this stability is to use a set of coils along the bottom of the magnet array on the

vehicle being levitated, which centers the vehicle over the rails by means of small amounts

of current. Because the voice coils are not needed to provide lift and there is almost no

drag, this system uses less power than other maglev systems: when the vehicle is centered

over the rails, it uses no power. As the vehicle navigates a curve, the controller moves the

vehicle to a balance point inside the curve so that the (magnetic) centripetal pull of the

magnetic rails in the ground offset the vehicles (kinetic) centrifugal momentum. Thisbalance point varies based on the vehicles weight, which the controller automatically

accounts for, resulting in zero steady state power consumption.

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INDUCTRACK SYSTEM:

The inductrack guide way would contain two rows of tightly packed levitation

coils, which would act as the rails. Each of these rails would be lined by two Halbacharrays carried underneath the maglev vehicle: one positioned directly above the rail and

one along the inner side of the rail. The Halbach arrays above the coils would provide

levitation while the Halbach arrays on the sides would provide lateral guidance that keeps

the train in a fixed position on the track.

The track is actually an array of electrically-shorted circuits containing insulated wire. In one

design, these circuits are aligned like rungs in a ladder. As the train moves, a magnetic field

repels the magnets, causing the train to levitate.

There are two inductrack designs. Inductrack I and II. Inductrack I is designed

for high speeds, while inductrack II is suited for slow speeds. Inductrack trains could levitate

higher with greater stability. As long as its moving a few miles per hour, an inductrack train

will levitate nearly an inch above the track. A greater gap above the track means that thetrain would not require complex sensing systems to maintain stability. Permanent magnets

had not been used before because scientists thought that they would not create enough

levitating force. The inductrack design bypasses this problem by arranging the magnets in a

Halbach array. The magnets are configured so that the intensity of the magnetic field

concentrates above the array instead of below it which generates higher magnetic field.

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The inductrack II design incorporates two Halbach arrays to generate a stronger

magnetic field at lower speeds. Dr. Richard post at the Livermore National Laboratory in

California came up with this concept in response to safety and cost concerns. The prototype

tests caught the attention of NASA, which awarded a contract to Dr.post and his team to

explore the possibility of using the inductrack system to launch satellites into orbit.

P R O P U L S I O NThis is a horizontal force which causes the movement of train. An EDS

system can provide both levitation and propulsion using an onboard linear motor. EMS

systems can only levitate the train using the magnets onboard, not propel it forward. As

such, vehicles need some other technology forpropulsion. A linear motor (propulsioncoils) mounted in the track is one solution. Over long distances where the cost of

propulsion coils could be prohibitive, a propellerorjet engine could be used.

It requires 3 parameters.

Large electric power

supply

Metal coil lining, a guide

way or track. Large magnet attached

under the vehicle.

PR IN CI PLE S OF LI NE AR M OT ORIts principle is similar to induction motor having linear stator and flat rotor. The

3-phase supply applied to the stator produces a constant speed magnetic wave, whichfurther produces a repulsive force.

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Ma gle v ve hi cl es a re pr op el led p ri ma ri ly by on e o f th e fo l lo win g t hr eeoptions:

1 .A linear synchronous motor (LSM) in which coils in the guideway are excited by athree phase winding to produce a traveling wave at the speed desired; Trans Rapid in

Germany employs such a system.

2. A Linear Induction Motor (LIM) in which an electromagnet underneath the vehicleinduces current in an aluminum sheet on the guideway.

3. A reluctance motor is employed in which active coils on the vehicle are pulsed at theproper time to realize thrust.

L A T ER A L GU IDI NG :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 exactlyanalogous 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.

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It requires the following arrangements:

Guideway levitating coil

Moving magnet

Also some systems use Null Flux systems (also called Null Current systems). These 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.

S T A B I L I T Y :Earnshaw's theorem shows that any combination of static magnets cannot be in a stable

equilibrium. 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 permeability is constant 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.

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Pros and cons of different technologies

Each implementation of the magnetic levitation principle for train-type travel involvesadvantages and disadvantages. Time will tell us which principle, and whose implementation,

wins out commercially.

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Tec hn o logyEMS(Electromagneti

c suspension)

ED S(Electrodynamic)

In du ctr ack Sys te m(Permanent

Magnet EDS)

ProsMagnetic fields inside and outside

the vehicle are less than EDS;

proven, commercially available

technology that can attain very high

speeds (500 km/h); no wheels or

secondary propulsion system

needed

Onboard magnets and large margin

between rail and train enable

highest recorded train speeds

(581 km/h) and heavy load capacity;has recently demonstrated

(December 2005) successful

operations using high temperature

superconductors in its onboard

magnets, cooled with inexpensive

liquid nitrogen

FailsafeSuspension - no power

required to activate magnets;Magnetic field is localized below the

car; can generate enough force at

low speeds (around 5 km/h) to

levitate maglev train; in case of

power failure cars slow down on

their own safely; Halbach arrays of

permanent magnets may prove

more cost-effective than

electromagnets

C o n sThe separation between the vehicle

and the guideway must be

constantly monitored and corrected

by computer systems to avoid

collision due to the unstable nature

of electromagnetic attraction; due

to the system's inherent instability

and the required constant

corrections by outside systems,

vibration issues may occur.

Strong magnetic fields onboard thetrain would make the train

inaccessible to passengers with

pacemakers or magnetic data

storage media such as hard drives

and credit cards, necessitating the

use ofmagnetic shielding;

limitations on guideway inductivity

limit the maximum speed of the

vehicle; vehicle must be wheeled

for travel at low speeds.

Requires either wheels or track

segments that move for when the

vehicle is stopped. New technology

that is still under development (as

of 2008) and as yet has no

commercial version or full scale

system prototype.

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NeitherInductrack nor the Superconducting EDS are able to levitate vehicles at a standstill,

although Inductrack provides levitation down to a much lower speed. Wheels are required

for these systems. EMS systems are wheel-less.

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complexities faced in magnetic levitation

Most of the levitation techniques have various complexities.

Many of the active suspension techniques have a fairly narrow region of stability.

Magnetic fields have no built-in damping. This can permit vibration modes to exist

that can cause the item to leave the stable region. Eddy currents can be stabilizing if

a suitably shaped conductor is present in the field, and other mechanical or

electronic damping techniques have been used in some cases.

Power and current requirements can be reasonably large to generate sufficiently

strong magnetic fields using electromagnets to lift significant mass.

Superconductors require very low temperatures to operate, often helium cooling is

employed.

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Comparison

Co mp ar ed to c onv ent io na l t ra insMajor comparative differences between the two technologies lie in backward-compatibility,

rolling resistance, weight, noise, design constraints, and control systems.

Ba ckw ards Co mp at ibi l i ty Maglev trains currently in operation are not compatible withconventional 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 extensionswhere traffic does not justify new infrastructure.

Efficiency Due to the lack of physical contact between the track and the vehicle, maglevtrains experience no rolling resistance, leaving only air resistance and electromagnetic drag,

potentially improving power efficiency.[13]

Weight The weight of the large electromagnets in many EMS and EDS designs is a majordesign 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 theelectromagnets, 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. [14][15]

De si gn Co mpa ris ons Braking and overhead wire wear have caused problems for theFastech 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.

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As with many technologies, advances in linear motordesign 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, inwhich the vehicle permanently levitated over 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.

Co nt ro l S yst em s EMS Maglev needs very fast-responding control systems to maintain astable 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.

Co mp ar ed to a ircra ftFor 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, athigh 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 trainsemit little carbon dioxide emissions, especially when powered by nuclear or renewable

sources.

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Recent advancement

In the far future Maglev trains are hoped to be used to transport vast volumes of water to farregions at a greater speed eliminating droughts. Far more, space is an open door to maglev

trains to propel humans and cargo into space at a lower cost. But most important is the New

York-London tunnel, which runs under the Atlantics water, to form the last stage of the

intercontinental highway. Scientists hope future technologies can get the train to operate at

a 6000km/h, since theoretically the speed limit is limitless. But still its a long way to go.

Transrapid International is developing an electromagnetic suspension system (EMS). They

have already demonstrated that it can reach 500Km/h with people on board. This speed can

get a passenger from Paris to Rome in 2 hours. The Swiss are considering a new 700km

system. The developers of these trains will most likely be connecting major cities up to

1600km away from each other, linking the busiest routes and exploiting their niche by being

the fastest mode of accessible transport. The costs of producing the guideway at the

moment still remain quite high at $10 million to $30million per mile.

If these technologies have the potential to reach 6000km/hr then why so far only 517km/hr

have been materialized? Well it is due to the fact that the speed of the vehicle is limited by

the air drag and the electromagnetic drag. Now electromagnetic drag has been overcome

by the use of Halbach array of magnets. And as for the air drag scientist are working overthe vacuum tubes for maglev vehicle but it has its own disadvantage as any defect in the

body of the vehicle would eventually put the life of people travelling. So a great work is still

to be done to overcome the air drag so as to improve the efficiency and cost efficiency.

Another area that still requires development is the development of the high temperature

superconductors. As of now the working of the superconductor needs less temperature

which is obtained by liquid nitrogen.

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magnetic on final report

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