The basic principle of magnetic levitation is very simple, that is, using the electromagnetic principle of "like charges repel each other, but opposite charges attract each other", the magnet can defying gravity the vehicle to float (generally not more than 1 cm), and then use electromagnetic force to guide and push the train forward. At present, it includes two specific structures.
(1) The first type is the normally conductive magnetic levitation represented by Germany. The track is a T-shaped platform. The lower parts of the two sides of the train should wrap the two sides of the T-shaped track, and the suspension is realized by the attraction between the conventional electromagnet installed at the bottom of the car body and the magnetic track located above the electromagnet. The advantage of normal maglev is simple technology, but the disadvantage is small electromagnetic attraction. The gap between the train and the track is about 8- 10 mm, and the speed of the normally oriented high-speed maglev train can reach 400-500km per hour.
Shanghai Pudong Airport Line adopts German constant magnetic levitation technology, which was completed by Transrapid Company of Germany on 200 1 from Shanghai Pudong International Airport in China to Longyang Road Station of the subway, and officially opened in 2002. The total length of the line is 30 kilometers, the maximum speed of the train is 430 kilometers per hour, the average running speed is 380 kilometers, the turning radius is 8000 meters, and it takes only 8 minutes from the starting point to the end point.
(2) The second is the superconducting maglev train system represented by Japan. Superconducting magnetic levitation is not a train track, but a train track. It uses the repulsive force generated by the superconducting magnet on the train and the induced magnetic field of the track to suspend on the track during the movement, and the train runs in the U-shaped groove. Superconducting magnetic levitation has a large air gap, generally around100 mm. Superconducting magnetic levitation has the advantages of large levitation force and fast train running speed, which can run at more than 500 kilometers per hour. Disadvantages are complex technology and low security.