Maglev trains can be divided into electromagnetic levitation (EMS) and electric levitation (EDS). The former is represented by Transrapid (TR)08 in Germany and HSST 100L maglev train in Japan, while the latter is represented by MLX superconducting maglev train in Japan.
Electromagnetic levitation, also known as gravity levitation, generally adopts "T" guide rail, and vehicles run around the guide rail. The vehicle-mounted suspension electromagnet placed under the guide rail is energized and excited to generate a magnetic field. Magnets and ferromagnetic parts on the track attract each other, and the train is lifted and suspended on the track. The suspension gap between the magnet and the ferromagnetic track is generally about 8 ~ 65438 02 mm. The train is driven by a linear motor by controlling the excitation current of the suspension magnet to ensure a stable suspension gap. Due to the principle that magnets attract each other, the magnetic field can basically form a closed loop between the primary and secondary coils of linear motors, and the magnetic field propagates less outward and the electromagnetic pollution degree is low, so the influence of the magnetic field on people can be ignored.
Electric levitation is also called repulsive levitation. When the train is running, the moving magnetic field of the vehicle-mounted magnet (usually a low-temperature superconducting coil or a permanent magnet) generates an induced current in the suspension coil installed on the line, and the interaction between the two generates an upward magnetic force, which suspends the train on the road at a certain height. The suspension clearance is generally 100 ~ 150 mm, and the train operation is also determined by. Compared with electromagnetic levitation, the electromagnetic levitation system can't levitate at rest, and it can only levitate after the train reaches a certain speed (about 150km/h). At the application speed, the suspension gap of the electric suspension system is large and there is no need for active control. Due to the principle that magnets repel each other, the magnetic field generated by the primary and secondary coils cannot be closed inside the linear motor, so its electromagnetic pollution is much greater than that of electromagnetic levitation.
German, Japanese, American, China and other countries are actively studying maglev train technology and have made great progress. German maglev railway system represented by EMS maglev train and Japanese maglev railway system represented by EDS maglev train are close to the application level: TR maglev train with constant conductivity and constant suction in Germany, MLX maglev train with superconducting repulsion in Japan and HSST maglev train with constant conductivity and constant suction in Japan. The maglev train being developed by Southwest Jiaotong University and National University of Defense Technology in China belongs to the normally conductive electromagnetic attraction suspension type.
Germany is the first country in the world to study maglev trains. 1922, Herman Qiang, a German, put forward the principle of electromagnetic levitation, and 1934 obtained the first patent of magnetic levitation technology in the world. Due to the limitation of technology and technology at that time, magnetic levitation technology has not been significantly developed in the following 30 years.
From 65438 to 0969, the German Federal Ministry of Transport, the Federal Railway Company and German industry participated in the "Research on High-speed and Fast Railway". The high-speed traffic studied involves wheel-rail high-speed railway and maglev high-speed railway. In February, 197 1, Germany's first maglev principle car MBB and a 660-meter-long test line were put into trial operation. The main vehicle is driven by a short stator linear motor on the vehicle side. 1975, Thyssen henschel took the lead in realizing the maglev train driven by the long stator linear synchronous motor on the HMB test line in Kassel factory. The test system combines linear drive with suspension support, which lays the foundation for the development of TR maglev high-speed railway today. The "Comet" test vehicle developed in 1976 proved for the first time that the maglev vehicle can run at a speed above 400 km/h. At 1979 Hamburg International Traffic Expo, a 900m-m-long TR maglev railway demonstration line was successfully exhibited, which promoted the development of maglev railway.
In order to build the first test line, German industry formed Transrapid consortium in maglev railway. The Trans-Rapid Test Line (TVE) was built in Emsland, northwest Germany. The first phase of the project includes a 2 1.5km long test line, a test center and a test vehicle Transrapid06 (TR06 for short). Considering the practical application in the future and improving the test speed, the Federal Ministry of Research and Technology decided to expand the South Ring Road of TVE 1984, which is the second section of the test line. South Ring Road 1984 started and 1987 was completed. So far, the total length of TVE test line has reached 3 1.5km, and in the same year, the speed of TR06 maglev vehicle on the test line has reached 40km/h, 1988, and the test speed has increased to 41.6 km/h.