Seminar Report On Maglev 1o1340

Seminar Report on

MAGNETIC LEVITATION TRAIN Presented by Debanka Chattopadhyay (36) Debrup Basu Mallick (37)

2016

Department of Mechanical Engineering Academy of Technology Adispatagram, Hooghly, West Bengal

India 712 121

Certificate This is to certify that the work presented in this Seminar Report has been prepared by Debanka Chattopadhyay (Roll No.36) and Debrup Basu Mallick (Roll No.37) being Fifth Semester B.Tech. Mechanical Engineering students of AOT, Adisaptagram.

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Statement by the candidate We hereby state that this technical report has been prepared by us is a record of our presentation on this topic. The report is being submitted to fulfill the requirements of Course ME581 of the curriculum of Academy of Technology, Adisaptagram, Hooghly, India 712121. Debanka Chattopadhyay Mallick (Roll No.36 / 5th Semester/ ME) Semester/ ME)

Debrup Basu (Roll No.37 / 5 th

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 effort in researching.

Acknowledgement In presenting seminar on “MAGNETIC LEVITATION TRAIN” we would like to convey our deep sense of gratitude to those who helped us a lot in preparing this seminar. At the outset we would like to thank our H.O.D. of Mechanical Engineering Department, Prof. A.K. Rana and Seminar Coordinator Prof. P. Dey for his timely suggestion in preparing this seminar. We would also like to thank our mentor, Prof. S. Dutta and also Prof. A. Kar for their valuable suggestions and guidance. We would also like to thank all faculty member of Mechanical Engineering Department who have been of immense help and in going through every minute detail of this seminar report and in providing valuable guidance every now and then. We would like to thank our friends for their , cooperation and encouragement throughout the seminar preparation till the entire presentation process.

Yours faithfully—

Debanka Chattopadhyay & Debrup Basu Mallick

Contents Certificate

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Endorsement

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Abstract

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Acknowledgement

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1. INTRODUCTION 1 2. BASIC PRINCIPLES OF MAGLEV TECHNOLOGY

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2.1. LEVITATION 3 2.2. PROPULSION 4 2.3. LATERAL GUIDANCE 3. TYPES OF MAGLEV TECHNOLOGY 6 3.1. ELECTROMAGNETIC SUSPENSION 7

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3.2. ELECTRODYNAMIC SUSPENSION 8 3.3. INDUCTRACK 9 4. TRACK 10 5. STABILITY 11 6. ENERGY USE 12 7. COMPARISON WITH CONVENTIONAL TRAINS 13 8. COMPARISON WITH AIRCRAFTS 14 9. PROS AND CONS OF MAGLEV 15-16 10. APPLICATIONS 17 11. CONCLUSION 18 12. REFERENCES 19

INTRODUCTION Transport along with communication, forms the core of day to day life of modern world. Conventional rail transport through wide spread is now being considered inefficient in of fuel consumption and is time consuming. A genuine replacement for railways which is not only fuel efficient but also highly comfortable and can attain unimaginable speeds of around 450 – 500km/hr are Maglev Trains whose idea was given by Robert Goddard, an American Rocket scientist, in 1904 who gave a theory that trains

could be lifted off the tracks by the use of electromagnetic rails. Many assumptions and ideas were brought about throughout the following years, but it was not until the 1970’s that Japan and showed interest in it and began researching and deg. The motion of the Maglev train is based purely on magnetism and magnetic fields. This magnetic field is produced by using highpowered electromagnets. By using magnetic fields, the Maglev train can be levitated above its track, or guide way, and propelled forward. Wheels and moving parts are eliminated on the Maglev train, allowing the Maglev train to essentially move on air without friction.

MAGLEV SYSTEM

BASIC PRINCIPLES OF MAGLEV TECHNOLOGY Magnetic levitation means “to rise and float in air”. The Maglev system is made possible by the use of electromagnets and

magnetic fields. The basic principle behind Maglev is that two magnets are placed together in a certain way there will be a strong magnetic attraction and the two magnets will clamp together. This is called "attraction". If one of those magnets is flipped over then there will be a strong magnetic repulsion and the magnets will push each other apart. This is called "repulsion". Now if a long line of magnets alternatively placed along a track and similarly on the bottom of the train and if these magnets are properly controlled the trains will lift of the ground by the magnetic repulsion or magnetic attraction and propel accordingly. Maglev trains have to perform the following functions to operate in high speeds: 1. Levitation – It helps in lifting of the train from the tracks.

2. Propulsion – It helps in movement of the train to attain speed.

3. Lateral Guidance – It prevents sideways movements of the train.

LEVITATION

Levitation is the process by which an object is held aloft, without mechanical , in a stable position. Levitation is accomplished by providing an upward force that counteracts the pull of gravity (in relation to gravity on earth), plus a smaller stabilizing force that pushes the object toward a home position whenever it is a small distance away from that home position. The force can be a fundamental force such as magnetic or electrostatic, or it can be a reactive force such as optical, buoyant, aerodynamic, or hydrodynamic. The electromagnets on the underside of the train pull it up the ferromagnetic stators on the track and levitate the train while the magnets on the side keep the train from moving from side to side. A computerised system changes the amount of current to keep the train 1cm to 10cm above guideway. Batteries on the train power the system, and therefore it still functions without propulsion. The batteries can levitate the train for about 30 minutes without any additional energy. Linear generators in the magnets on board the train use the motion of the train to recharge the batteries with a dynamo or alternator.

 This means there is no friction between the train and the track!

PROPULSION

Propulsion is a means of creating force leading to movement. A propulsion system consists of a source of mechanical power, and a propulsor which converts the power into propulsive force. Electrodynamics Propulsion is the basis of the movement in a Maglev system. The basic principle that electromagnetic propulsion follows is that “opposite poles attract each other and like poles repel each other”. This meaning that the north pole of a magnet will repel the north pole of a magnet while it attracts the south pole of a magnet. Likewise, the south pole of a magnet will attract the north pole and repel the south pole of a magnet.

The system consists of aluminium or copper three-phase cable windings in the stator packs that are on the guideway. When a current is supplied to the windings, it creates a traveling alternating current that propels the train forward by pushing and pulling. When the alternating current is reversed, the train brakes. Different speeds are achieved by varying the intensity of the current. Only the section of track where the train is traveling is electrified.

 This means there is no requirement of an engine!

LATERAL GUIDANCE The Lateral guidance systems control the train’s ability to actually stay on the track. It stabilized the movement of the train from moving left and right of the train track by using the system of electromagnets found in the undercarriage of the Maglev train. The placement of the electromagnets in conjunction with a computer control system ensures that the train does not deviate more than 10mm from the actual train tracks. Null flux systems are generally used.These use a coil known as guidance electromagnet that is wound so that it enters two opposing, alternating fields, so that the average flux in the loop is zero. When the vehicle is in the straight ahead position, no current flows, but any moves off-line create flux that generates a field that naturally pushes/pulls it back into line. The magnetic fields created are perpendicular to the electric current, thus making the magnetic fields stronger. This system dampens the effect of the side to side vibrations of the train car and allows for more comfortable train rides. This stable lateral motion caused from the magnetic propulsion is a t operation from the acceleration sensor, control device, to the actual air spring that dampens the lateral motion of the train.

The levitation coils are connected on both sides of the guide way and have opposite poles. The opposite poles of the guide way cause a repulsive force on one side of the train while creating an attractive force on the other side of the train. In addition to guidance, these magnets also allow the train to tilt, pitch, and roll during turns. To keep all distances regulated during the ride, the magnets work together with sensors to keep the train centered.

TYPES OF MAGLEV TECHNOLOGY Based on the techniques used for Levitation there are of following types of Maglev trains:

1. Electromagnetic Suspension (EMS) In EMS system“LEVITATION BY ATTRACTION “ may takes place.

2. Electrodynamic Suspension (EDS) IN EDS SYSTEM “LEVITATION BY REPULSION” may takes place.

3. Inductrack System The Inductrack is a newer type of EDS that uses permanent room temperature magnets.

ELECTROMAGNETIC SUSPENSION (EMS) Electromagnetic Suspension uses electromagnets to levitate the train.

. Attraction is caused by having the currents within each of the circuits traveling in the same direction. It is important to note that with attractive forces created between the train and the track.

The propulsion of the train is mainly based on two types of motors: Linear Electric Motor (LEM) and Linear Induction Motor (LIM). The levitation magnets and rail are both U shaped (with rail being an inverted U). The mouths of ‘U’ face one another which helps in lateral guidance.

ADVANTAGES Magnetic fields inside and outside the vehicle are less than EDS and is proven as commercially available technology that can attain very high speeds (500 km/h). Moreover, no wheels or secondary propulsion system needed. DISADVANTAGES The 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 and due to the system's inherent instability and the required constant corrections by outside systems, vibration issues may occur.

ELECTRODYNAMIC SUSPENSION (EDS) Electrodynamic Suspension uses ‘Superconductors’ for levitation, propulsion and lateral guidance.

The current in the top circuit travels in the opposite direction of the current in the bottom resulting in an repulsion between the two coils producing a lift resulting in levitation. 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. When one side of the train nears the side of the guideway, the super conducting magnet on the train induces a repulsive force from the levitation coils on the side closer to the train and an attractive force from the coils on the farther side. This keeps the train in the center. ADVANTAGES Onboard magnets and large margin between rail and train enable highest recorded train speeds (581 km/h) and heavy load capacity. DISADVANTAGES There is necessary use of magneting shielding due to the strong magnetic fields. The vehicle must be wheeled to travel at low speed.The cryogenic system used to cool the coils can be expensive like liquid nitrogen.

INDUCTRACK Inductrack is a ive, fail-safe electrodynamic magnetic levitation system, using only unpowered loops of wire in the track and permanent magnets (arranged into Halbach arrays) on the vehicle to achieve magnetic levitation. The track can be in one of two configurations, a "ladder track" and a "laminated track". The ladder track is made of unpowered Litz wire cables, and the laminated track is made out of stacked copper or aluminium sheets.

There are three Inductrack designs:  Inductrack I  Inductrack II  Inductrack III Inductrack I is designed for high speeds, while Inductrack II is suited for slow speeds and Inductrack III is intended for heavy loads at low speed. ADVANTAGES There is no requirement of power to activate magnets. Magnetic field is localized below the car and can generate enough force at low speeds (around 5 km/h) to levitate Maglev train. In case of power failure trains slow down on their own safely. Even Halbach array arrangement of permanent magnets may prove more cost-effective than electromagnets. DISADVANTAGES It requires either wheels or track segments that move for when the vehicle is stopped. Moreover. It is a new technology that is still under development and as yet has no commercial version or full scale system prototype.

TRACK The term "maglev" refers not only to the vehicles, but to the railway system as well, specifically designed for magnetic levitation and propulsion. They cannot share existing infrastructure, maglev systems must be designed as standalone systems.

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 TRACK It consists of Halbach Array arrangement which possess onesided flux structure. A Halbach array is a special arrangement of permanent magnets that augments the magnetic field on one side of the array while cancelling the field to near zero on the other side. This is achieved by having a spatially rotating pattern of magnetisation. Generally grade 38, Neodymium-Iron Boron (NdFeB) is used.

STABILITY No combination of static magnets can be in a stable equilibrium. Therefore, a dynamic (time varying) magnetic field is

required to achieve stabilization. EMS systems rely on active electronic stabilization that constantly measures the bearing distance and adjusts the electromagnet current accordingly. EDS systems rely on changing magnetic fields to create currents, which can give ive stability. Because maglev vehicles essentially fly, stabilisation of pitch, roll and yaw is required. In addition to rotation, surge (forward and backward motions), sway (sideways motion) or heave (up and down motions) can be problematic. Superconducting magnets on a train above a track made out of a permanent magnet lock the train into its lateral position. It can move linearly along the track, but not off the track. This is due to the Meissner effect and flux pinning. o

Meissner effect is the expulsion of a magnetic field from a superconductor during its transition to the superconducting state.

Diagram of the Meissner effect. Magnetic field lines, represented as arrows, are excluded from a superconductor when it is below its critical temperature

o Flux pinning is the phenomenon where a superconductor is pinned in space above a magnet.

Flux Pinning: Flux Tube diagram

ENERGY USE Energy for maglev trains is used to accelerate the train. Energy may be regained when the train slows down via regenerative braking. It also levitates and stabilises the train's movement. Most of the energy is needed to overcome "air drag". Some energy is used for air conditioning, heating, lighting and other miscellany.

A regenerative brake is an energy recovery mechanism which slows a vehicle or object by converting its kinetic energy into a form which can be either used immediately or stored until needed. This contrasts with conventional braking systems, where the excess kinetic energy is converted to unwanted and wasted heat by friction in the brakes. In addition to improving the overall efficiency of the vehicle, regeneration can greatly extend the life of the braking system as its parts do not wear as quickly.

At low speeds the percentage of power used for levitation can be significant, consuming up to 15% more power than a subway or light rail service. For short distances the energy used for acceleration might be considerable.

The power used to overcome air drag increases with the cube of the velocity and hence dominates at high speed. The energy needed per unit distance increases by the square of the velocity and the time decreases linearly. For example, 2.5 times more power is needed to travel at 400 km/h than 300 km/h.

COMPARISON WITH CONVENTIONAL TRAINS 

Speed: Maglev allows higher top speeds than conventional rail.

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Maintenance: Maglev trains currently in operation have demonstrated the need for minimal guideway maintenance. Traditional rail is subject to mechanical wear and tear that increases exponentially with speed, also increasing maintenance due to friction.

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Weather: Maglev trains are little affected by snow, ice, severe cold, rain or high winds.

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Track: Maglev trains are not compatible with conventional track, and therefore require custom infrastructure for their entire route.

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Efficiency: Conventional rail is probably more efficient at lower speeds. But due to the lack of physical between the track and the vehicle, maglev trains experience no rolling resistance, leaving only air resistance and electromagnetic drag, potentially improving power efficiency.

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Weight: The use of superconductor magnets can reduce the electromagnets' energy consumption. A 50-ton Transrapid maglev vehicle can lift an additional 20 tons, for a total of 70 tons, which consumes 70-140 KW. Most energy use for the TRI is for propulsion and overcoming air resistance at speeds over 100 mph.

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Weight loading: High speed rail requires more and construction for its concentrated wheel loading. Maglev cars are lighter and distribute weight more evenly.

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Noise: Because the major source of noise of a maglev train comes from displaced air rather than from wheels touching rails,

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 experience a 5–10 dB "bonus", as they are found less annoying at the same loudness level. 

Braking: Braking and overhead wire wear have caused problems for the conventional trains but Maglev would eliminate these issues.

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Magnet reliability: At higher temperatures magnets may fail. New alloys and manufacturing techniques have addressed this issue.

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Control systems: No signalling systems are needed for highspeed rail, because such systems are computer controlled. Human operators cannot react fast enough to manage highspeed trains. High speed systems require dedicated rights of way and are usually elevated.

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Terrain: Maglevs are able to ascend higher grades, offering more routing flexibility and reduced tunnelling.

COMPARISON WITH AIRCRAFTS

 Efficiency: For maglev systems the lift-to-drag ratio 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 kilometer. However, at high cruising speeds, aerodynamic drag is much larger than liftinduced drag. Jets take advantage of low air density at high altitudes to significantly reduce air drag. Hence despite their lift-to-drag ratio disadvantage, they can travel more efficiently at high speeds than maglev trains that operate at sea level.

 Routing: While aircraft can theoretically take any route between points, commercial air routes are rigidly defined. Maglevs offer competitive journey times over distances of 800 kilometres (500 miles) or less. Additionally, maglevs can easily serve intermediate destinations.  Availability: Maglevs are little affected by weather.  Safety: Maglevs offer a significant safety margin since maglevs do not crash into other maglevs or leave their guideways.  Travel time: Maglevs do not face the extended security protocols faced by air travelers nor time is consumed for taxing, or for queuing for take-off and landing.

PROS AND CONS OF MAGLEV ADVANTAGES Magnetic Fields  Intensity of magnetic field effects of Maglev is extremely low (below everyday household devices).

Energy Consumption  Maglev uses 30% less energy than a highspeed train traveling at the same speed. (1/3 more power for the same amount of energy) Noise Levels  No noise caused by wheel rolling or engine.  Maglev noise is lost among general ambient noise.  At 100m - Maglev produces noise at 69 dB. Vibrations Vibrations below human threshold of perception. Power Supply  110kV lines fed separately via two substations. Power Failure  Batteries on board automatically are activated to bring car to next station  Batteries charged continuously Fire Resistance of vehicles  Latest non-PVC material used that is non-combustible and poor transmitter of heat.  Maglev vehicle carries no fuel to increase fire hazard.

Safety

 Collision is impossible because only sections of the track are activated as needed. The vehicles always travel in synchronization and at the same speed, further reducing the chances of a crash. Operation Costs  Virtually no wear. Main cause of mechanical wear is friction. Magnetic Levitation requires no , and hence no friction.  Components normally subjected to mechanical wear are on the whole replaced by electronic components which do not suffer any wear.  Specific energy consumption is less than all other comparable means of transportation.  Faster train turnaround time means fewer vehicles.

DISADVANTAGES There are several disadvantages with maglev trains. Maglev guide paths are bound to be more costly than conventional steel railways. 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, 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. Although it is not seen anywhere a solution could be to put normal steel wheels onto the bottom of a maglev train, which would

allow it to run on normal railway once it was off the floating guideway.

APPLICATIONS  System is introduced as Test Tracks in –  San Diego, USA  SC Maglev, Japan  FTA's UMTD Program  Southwest Jiaotong University, China

 Operational system of MAGLEV are in –  Shanghai Maglev  Linimo (Tobu Kyuryo Line, Japan)  Incheon Airport Maglev  Changsha Maglev

 Other applications include –  NASA plans to use magnetic levitation for launching of space vehicles into low earth orbit.  Boeing is pursuing research in Maglev to provide a Hypersonic Ground Test Facility for the Air Force.  The mining industry will also benefit from Maglev.

 Possible uses could include:  Rocket launching

 Aircraft carrier launching pad  Space craft launching  There are probably many more undiscovered applications!

CONCLUSION Railways using MagLev technology are on the horizon. They have proven to be faster than traditional railway systems that use metal wheels and rails and are slowed by friction. The low maintenance of the MagLev is an advantage that should not be taken lightly. When you don’t have to deal with the wear and tear of friction you gain greater longevity of the vehicle. Energy saved by not using motors running on fossil fuels allow more energy efficiency and environmental friendliness. Maglev will have a positive impact on sustainability. Using superconducting magnets instead of fossil fuels, it will not emit greenhouse gases into the atmosphere. Energy created by magnetic fields can be easily replenished. The track of a Maglev train is small compared to those of a conventional train and is elevated above the ground so the track itself will not have a large effect on the topography of a region. Since a Maglev train levitates above the track, it will experience no mechanical wear and thus will require very little maintenance. Overall, the sustainability of Maglev is very positive. Although the relative costs of constructing Maglev trains are still expensive, there are many other positive factors that overshadow this. Maglev will contribute more to our society and our planet than it takes away. Considering everything Maglev has to offer, the transportation of our future and our future generation is on very capable tracks.

REFERENCES  www.wikipedia.org/wiki/Maglev

 “MagLev Ready for Prime Time.” Issues Science Technology 19 No. 4 Summer 2003 Article

 www.getransportation.com

 Bonsor, Kevin. “How Maglev Trains Work”.  www.powerlabs.org/railgun.htm  https://en.wikipedia.org/wiki/Transrapid

 The Maglev 2016 in Berlin - International Transport Conference Magazine  The Magnetic Levitation Train: A Technology Ahead of Its Time written by Jens Hillebrand