MAGLEV Train : How Does It Works?

What is meant by maglev?

Maglev (from magnetic levitation) is a system of train transportation that uses two sets of magnets: one set to repel and push the train up off the track, and another set to move the elevated train ahead, taking advantage of the lack of friction. Along certain "medium-range" routes (usually 320 to 640 km (200 to 400 mi)), maglev can compete favourably with high-speed rail and airplanes.

Principle of magnetic levitation

The creation of magnetic forces is the basis of all magnetic levitation. The creation of a magnetic field can?be caused by a number of things. The first thing that it can be caused by is a permanent magnet. These magnets are a solid material in which there is an induced North and South pole. The second way that an magnetic field can be created is through an electric field changing linearly with time. The third and final way to create a magnetic field is through the use of direct current. This magnetic field creation are based on the Michael Faraday’s law.

The principle is that two same magnetic poles repel, and two different poles attract, with forces that are stronger when the poles are closer. There are four magnetic forces on the top: on its north pole, repulsion from the base's north and attraction from the base's south, and on its south pole, attraction from the base's north and repulsion from the base's south. Because of the way the forces depend on distance, the north-north repulsion dominates, and the top is magnetically repelled. It hangs where this upward repulsion balances the downward force of gravity, that is, at the point of equilibrium where the total force is zero.

Working of maglev train

Maglev trains work on the principle of magnetic repulsion between the cars and the track. The magnetic levitation, or floating of the train, is achieved through the use of an electrodynamic suspension system, or EDS.

The rails, or guideways, contain two sets of cross connected metal coils wound into a “figure eight” pattern to form electromagnets. On the train itself are superconducting electromagnets, called bogies. When stopped, the train rests on rubber wheels. To begin motion, the train moves forward slowly on these wheels, allowing the magnets beneath the train to interact with those of the guideway. Once the train reaches 150 kilometers per hour (93 miles per hour), the magnetic force is strong enough to lift the train 100 milimeters (4 inches) off the ground, eliminating friction to allow for increasingly high speeds.

Advantages of maglev train

• Extremely fast speed up to 500 km/hr.
• Really quiet operation.
• Maglev uses less energy up to 30% than normal trains.
• Due to lack of physical contact between train and track, very efficient for maintenance.

References:

Maglev. Retrieved from https://en.wikipedia.org/wiki/Maglev

Pros/Cons of Maglev Train. Retrieved from https://ffden-2.phys.uaf.edu/212_spring2011.web.dir/Chan_Jeon/proscons-of-maglev-train.html

Rathore, P., Sen, P. K., & Sahu, G. (2015). An Review on Magnetic Levitation Principle and It's Applications. International Journal of Engineering and Management Research (IJEMR), 5(5), 84-87.

The Japanese Maglev: World’s fastest bullet train. Retrieved from https://www.jrailpass.com/blog/maglev-bullet-train