What are maglev trains you may ask yourself?
First of all, maglev is an abbreviation of magnetic levitation. This is the levitation coming from strong magnets that produce a magnetic field which keeps the trains off the ground. The train uses magnets to hover above the ground and move. There are two different types of this method. The first one is from Japan. Their method of using magnetic levitation is called EDS also known as electrodynamic suspension. And the other method is in Germany and is called EMS, or electromagnetic suspension. But both can revolutionize our way of transportation as they are both faster, smoother, quieter, and have longer service than regular wheeled mass transit trains.
Explaining magnetic levitation
All magnets have two poles. They both have a north and south pole. If the north pole of one magnet gets close to the south pole of another magnet, they attract each other and join together. But if the north pole of one magnet is near the north pole of another magnet, it is pushed back and repelled. The force separating the same poles of two magnets can be used for levitation purposes. It is this simple idea that led to the first prototypes of a maglev train.
The Japanese Transrapid train
This type of maglev train is inspired from the german transrapid train. Nevertheless their configurations are different with a few pros and cons. One of the differences is the structure of the magnets. The magnets in the EDS train are placed in a position to the sides of the train. Another difference is that the Japanese use EDS magnets, which is a type of magnet also known as a superconductive magnet. This magnet is somewhat better than the magnets used in the German transrapid train. The superconductive magnets use cold temperatures to generate power in the magnet. They are placed all along the inside of the train. Those magnets interact with coils in the guideway that then makes the train achieve a total levitation height of 10 centimeters. To make the train move forward, the train uses propulsion from a linear synchronous motor that is located behind the coils in the guideway. Now with these superconductive magnets, they are able to produce electricity themselves making the Japanese transrapid train a very power saving train.
The German Transrapid train
For this method of using magnets and the concept of levitation is about the same as the Japanese transrapid train. But one great difference between the two trains is that this german EMS train wraps around the guideway instead of having wall to each side like the Japanese EDS train. Another difference is the magnets. For the magnets used in EMS, they use iron core electromagnets and ferromagnetic rail magnets. The iron core magnets are placed on the underside of the guideway. These magnets are a part of the train. For the ferromagnetic rail magnets, they're placed on the underside of the guideway and are part of the guideway. The ferromagnetic rail magnets attract the iron core magnets and leaves a gap of 10 centimeters between those magnets. This holds the train up 15 centimeters off the guideway, meaning this is producing the trains levitation. The train moves forward by using the iron core magnets providing an alternating current that then creates a repelling force resulting in forward movement.
In the picture below it shows the different guideways and arrangement of magnets.
- For the EMS diagram, the purple represents the iron core magnets, and the green represents the ferromagnetic rail magnets.
- For the EMS diagram, the purple represents the iron core magnets, and the green represents the ferromagnetic rail magnets.
Just to cover on how its a bit confusing, here's just a simple example on how the levitation works. The magnets on the guideway produce a magnetic field that then propels the magnets on the train thus creating levitation.
CITATIONS
Website 1: How Stuff Works - URL: http://science.howstuffworks.com/transport/engines-equipment/maglev-train.htm
Website 2: Wikipedia - URL: https://en.wikipedia.org/wiki/Maglev
Website 3: Youtube Video - URL: https://www.youtube.com/watch?v=EbORQVttbeU
Extra information: Ms. Tong
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Credits:
Created with images by maxintosh - "Maglev" • MDGovpics - "SC Maglev Test Ride" • Traveloscopy - "Maglev"