INTRODUCTION<br /><ul><li>Maglev is the best alternative for means of transport.
Maglev runs on the principle of magnetic levitation.
Maglev is noiseless ,friction less , and require no maintenance.
The lack of friction allow maglev vehicle to travel at a speed over 300 miles/hr.
Electrified transport reduces pollution.</li></li></ul><li>Maglev<br /> High-speed rail technology; train is suspended on a magnetic cushion above a magnetized track and so travels free of friction<br />
Transrapid <br />Transrapid train is a German monorail system using magnetic levitation. Based on a patent from 1934, planning of an actual Transrapid system started in 1969. <br />
The test facility for the system in Emsland, Germany was completed in 1987, and in 1989 a Transrapid train reached a record breaking speed of 436 kilometers per hour.<br />
Basic Principle of Maglev Trains<br />Maglev trains have to perform the following functions to operate in high speeds<br /> 1. Leviation<br /> 2. Propulsion<br /> 3. Lateral Guidance<br />
Types of Maglev Trains<br />Based on the technique used for Leviation the <br />are two types of Maglev trains<br />1. Electromagnetic Suspension -Attractive<br />2. Electrodynamic Suspension -repulsive<br />
Electromagnetic Suspension(EMS)<br />Electromagnetic Suspension uses electromagnets to leviate the train<br />
Electrodynamic Suspension<br />Electrodynamic Suspension uses Superconductors for leviation, propulsion and lateral guidance<br />
The Maglev system<br />The Maglev system applies the superconducting technology of low-temperature superconductors, Nb-Ti wires, and SCMs that require liquid helium as a coolant. In addition to these well-developed technologies, high-critical temperature superconductors that show superconductivity at liquid nitrogen are also prospective components for the Maglev system.<br />
Levitation System’s Power Supply<br />Batteries on the train power the system, and therefore it still functions without propulsion. <br />The batteries can levitate the train for 30 minutes without any additional energy.<br />Linear generators in the magnets on board the train use the motion of the train to recharge the batteries.<br />Levitation system uses less power than the trains air conditioning.<br />
<ul><li>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.</li></li></ul><li>Principle of Magnetic Leviation<br />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.<br />
<ul><li>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.</li></li></ul><li>Principle of Lateral Guidance<br /><ul><li>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. </li></li></ul><li><ul><li>The levitation magnets and rail are both </li></ul> U shaped(with rail being an inverted U). <br /><ul><li>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.</li></li></ul><li>Superconductivity<br />Superconductivity occurs in certain materials at very low temperatures. <br />When superconductive, a material has an electrical resistance of exactly zero. <br />It is also characterized by a phenomenon called the Miessner effect. This is the ejection of any sufficiently weak magnetic field from the interior of the superconductor as it transitions into the superconducting state.<br />
The SCM (Super Conducting Magnet) <br /><ul><li>Each SCM 4 SC coils. The SCM features high reliability and high durability.
The cylindrical unit at the top is a tank holding liquefied helium and nitrogen.
The bottom unit is an SC coil alternately generating N poles and S poles. </li></li></ul><li>
<ul><li>An EDS system can provide both leviation and propulsion using an onboard linear motor.
EMS systems can only levitate the train using the magnets onboard, not propel it forward.
Over long distances where the cost of propulsion coils could be prohibitive, a propeller or jet engine could be used.</li></li></ul><li>Propulsion<br /><ul><li>An alternating current is ran through electromagnet coils on the guide walls of the guide way. This creates a magnetic field that attracts and repels the superconducting magnets on the train and propels the train forward.
Braking is accomplished by sending an alternating current in the reverse direction so that it is slowed by attractive and repulsive forces.</li></li></ul><li><ul><li>The system consists of aluminum 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.</li></li></ul><li> Advantages of Magnetic Levitated Transportation System <br /><ul><li>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. </li></li></ul><li><ul><li>Maglev vehicle carries no fuel to increase fire hazard
The materials used to construct maglev vehicles are non-combustible, poor penetration transmitters of heat, and able to withstand fire.</li></li></ul><li>Disadvantage or incidents of<br />maglev trains<br />Twenty-three people were killed and around 10 injured <br />At this time, the accident was not caused by a technical failure.<br />
Other Applications <br />NASA plans to use magnetic levitation for launching of space vehicles into low earth orbit. <br />Boeing is pursuing research in MagLev to provide a Hypersonic Ground Test Facility for the Air Force. <br />The mining industry will also benefit from MagLev. <br />There are probably many more undiscovered applications! <br />
Current Projects <br /><ul><li>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
Germany and Japan have been the pioneering countries in MagLev research</li></li></ul><li> Conclusion <br />The MagLev Train: Research on this ‘dream train' has been going on for the last 30 odd years in various parts of the world. <br />The chief advantages of this type of train are: <br /> Non-contact and non-wearing propulsion, independent of friction, no mechanical components like wheel, axle. <br />Maintenance costs decrease<br />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 explore….<br />