MAGLEV : THE LEVITATOR; EDS AND EMS TECHNOLOGY

As the network of high speed railways become the dream of every country. Almost all the countries are effortlessly working on their high-speed project and aims to provide such transport which gives a jet speed on ground. Today, this post is not about any facts and information regarding Indian Railways. This post would describe about the biggest success of Japanese Railways and a technology system which remarks the history of railways in the world. So, the post includes the fastest, the floater, the magnificent rail system: the ‘MAGLEV’.

The following post includes the discussion of ‘MAGLEV’ system, the EDS and EMS technology explanation and finally the Japan’s supreme ‘SCMaglev’.

MAGLEV: - INTRODUCTION

The MAGLEV (MAG: magnetic, LEV: levitation) is the system which uses the magnetic propulsion technique for rail transportation. The system makes use of two system of magnets, one system of magnets which uses magnetic repulsion property to float the whole train in air and other system of magnets which propel the train ahead at high speed. Thus, this system propels the train in air removing all the friction of tracks. This enables it to take high speed with floating technique removing all the contact with the ground.

The Maglev system makes propulsion and lifting along the guideways, in which series of magnets are attached in guideways with magnets attached in bogies. The magnets are generally electromagnets or induced magnets by Lenz’s law due to relative motion. The interesting point being that the no parts in whole system is in motion as train floats on magnets so the system makes no use of motor and less energy consumption.

MAGLEV: EMS, GERMANY

MAGLEV: EDS, JAPAN

The evolution of 'maglev' is followed by the two main technologies which headed the whole project:

1. 'Maglev' system in Germany making use of EMS technology.

2. 'Maglev' system in Japan making use of EDS technology.

Let’s discuss each of them in detail:

PROPULSION SYSTEM

Before starting, we should discuss the propulsion system i.e. how the train moves forward with help of magnets. The guideways which provides direction and stability to train, contains the series of north and south pole electromagnets placed alternatively with each other as NSNSNS…. fitted along the side of guideways. These series are fixed on both sections of the guideways. The series are then connected with alternator which supplies alternating current to electromagnets with certain frequency. Thus the polarity of magnets would continuously changes as NSNSNS.. to SNSNSN.. then NSNSNS… and so on, depending upon the frequency of current. In same way, the bogies are fitted with such series of electromagnets which also changes the polarity due to alternating current with same frequency. Here, the frequency of both currents, in bogies and guideways should be equal to make propulsion possible.

Thus, the previous magnet of guideway will repel the magnet of bogies in the series and at same time, the forward magnet of guideway will attract the same magnet of bogie in the series. Thus, the both effects makes a forward resultant and train moves forward. Again, in next phase the same thing happens and train moves so on. The speed of train will depend upon the frequency of change of alternating current in both series of bogies and train.

Propulsion system

ELECTRO-MAGNETIC SUSPENSION(EMS) TECHNOLOGY

The EMS technology simply uses the attractive force of the magnet to lift the train in air. The attractive force between the electromagnets fitted below of guideways and above the bogies lift the train against the gravitational force at about 5cm from guideways. The propulsion system fitted alongside of guideways helps the train to move forward. As the train surrounds the guideways, it stabilizes the unit during the motion. in this process, the train remains lifted even at low speeds as long as current flows into the electromagnets. In case of power failure, emergency batteries are provided for current supply preventing collision with guideways.

EMS TECHNOLOGY

ELECTRO-DYNAMIC SUSPENSION(EDS) TECHNOLOGY

The EDS technology are first developed by Japanese engineer in 1998. The EDS system basically uses the super-cooled, superconducting electromagnets unlike the normal electromagnets. This develops the strong electric field as compared to EMS. The supercooled will conduct electricity even after the power supply and enables the train energy saving and to move even on power cuts. However, the cryogenic system is required to keep coils supercooled.

The EDS system makes uses of repulsion of magnets for lifting of train. The train usually lifts 10cm above the guideways through coils in the guideways below the magnets. The electromagnets induce current in coils which creates opposite polarity to repel and lift the train. However, the train has to run at rubber wheels till it attains the speed of 100km/hr, after which it lifts up above the ground. The rubber wheels were considered beneficial as the train moved even after power failure when train comes in contact of guideways. The train moves forward making same use of propulsion system of magnets.

EDS TECHNOLOGY 

The essential difference between the EMS and EDS technology is that the magnetic fields are very strong in EDS than EMS. Thus, the EMS has less effects of magnetic field inside the train having strength same as earth magnet making suitable for person with pacemakers or carrying the magnetic material as hard disk etc. whereas the train are to be shielded in EDS technology to prevent the effect of magnetic field on persons otherwise it leads to serious problems.

SCMAGLEV (THE JAPANESE PROJECT)

The ScMAGLEV (SuperConducting MAGnetic LEVitation) is the Japan’s high-speed rail project making same use of EDS technology for trains. The project was first started on year 1998 after which it is successfully trailed on June 2015 on YAMANASHI test track. The 335 kilometres track laid between the Tokyo and Shanghai helps to attain the speed of 602km/hr, the highest speed attained in the world. Afterwhich, several tests were held which mark the successful completion of Maglev project.

The 'ScMaglev' again make use of supercooled electromagnets for levitation. The guideways contain the series of 8-shaped coils fixed side by side and coils fitted below the guideways. When train attains the speed of 100km/hr, the current induced due to change in flux in coils created north and south pole simultaneously on both ends of 8-shaped coils. The magnets fitted on side of train will experience a simultaneous attractive and repulsive forces which lifts the train and the coils fitted perpendicular to these coils will propel the train at a high speed of 600km/hr. The forces induced when train tilts to other side will pull back the train to its original position and provides stabilization.

Even though the system was considered to be expensive, but the dream of high speed projects will accomplished due to these trials.   


REFERENCES:

TEXTS: WIKIPEDIA, RAILOPEDIA
IMAGES: GOOGLE IMAGES