Maglev technology can solve the problems of wheel-rail adhesion, hunting instability, running noise and pantograph-OCS speed limit existing in the wheel-rail transit systems, and can further improve the ground transport speed. Maglev technology was put forward by German scholars as early as 1920s. Since 1960s, it has received extensive attention from Germany, Japan and other developed countries. In recent years, with the continuous development of German EMS maglev technology and Japanese low temperature superconducting maglev technology, the concept of "Hyperloop" has received increasing popularity, and with the launch and promotion of Japan's Chuo Shinkansen Maglev Line project, maglev railway has gradually become the focus in the field of ground transport, and many countries have actively researched and promoted relevant technologies. From the perspective of current development situation, maglev railway will present the following development trends in the future.
On the one hand, maglev railway's highest test speed has been continuously rising and has now exceeded 600 km/h. Japan's Yamanashi Maglev Test Line set a world record of 603 km/h in the manned running test in 2015, surpassing the highest test speed of 550 km/h for German EMS maglev technology. On the other hand, many countries and companies said that the highest speed of the maglev system based on low vacuum pipeline can reach more than 1,000 km/h. In the United States, Elon Musk proposed that the theoretical speed of Hyperloop Alpha could reach 1,223 km/h. In China, Southwest Jiaotong University planned to carry out research on high temperature superconducting maglev technology based on vacuum pipelines with a speed of more than 1,000 km/h. In Canada, Transpod proposed to develop an "Hyperloop" with a speed of 1,000 km/h.
The Japan-led technology of electrodynamic suspension (EDS) represents one of the key means to deliver maglev railway. With high environment requirements, the low temperature superconducting materials used in Japan today poses high engineering costs and potential safety hazards. In contrast, high temperature superconducting materials - with fairly high critical temperatures – promises extraordinary convenience in engineering applications.
At present, many countries including the United States and Japan are carrying out research on high temperature superconducting materials. The U.S. High Temperature Superconducting Materials Analysis and Forecast Report, released by the U.S. Department of Energy in 2011, points out that high temperature superconducting materials will drive the development of transport in the next 5-15 years, and maglev technology offers an important application case. Japan is also taking an active approach in the testing of the material which may serve as an alternative to the low temperature superconducting materials widely used in the country.
Maglev railway can be categorized – by speed - into medium-/low-speed maglev railway, high speed maglev railway and super high speed low-vacuum maglev pipeline. As each category is catered to specific transport requirements, the complexity and maturity of technologies are at different stage of development, therefore the prospects for future application are differentiated.
The medium-/low-speed maglev railway – well suited for short distance transport – has accumulated mature technologies, with the lines in operation including the Aichi High speed Transit Tobu Kyuryo Line in Japan (Linimo), the Incheon Airport Maglev Train in South Korea, and the Changsha Maglev Express and the Beijing Subway Line S1 in China, etc. Its outstanding performance in noise emission, construction costs and energy consumption means that it is mainly applied to urban areas and other short distance transport.
High speed maglev railway – standing out for its speed, noise and environment performances – enjoys mature technologies, however it lacks successful attempts in commercial applications. So far, the only application case in the world is the Shanghai Maglev Train Line in China. That being said the operator can hardly make ends meet, while a host of issues in the areas of safety and economic performance are still to be resolved.
Going forward, the development goals for high speed maglev railway are to cut construction and operation costs, and make the technologies more practical. As the ground transport system with the highest speed-up potential, the low-vacuum maglev pipeline is still at the stage of theoretical research and testing. The primary task is to solve the technical problems of blockage ratio of pipeline, heat dissipation in the pipeline and a series of system coupling. There is still a long way to go for practical engineering application.
With the technical and economic characteristics of a new type of transport mode, the low-vacuum maglev pipeline stands out for its speed, energy and environment performances, as well as its capability to implement all-weather transport. It is expected that the mode of transport will trigger new passenger traffic demand and promote the transfer of passenger traffic to railway, facilitating the increase of market share, the raise of operation revenue and the obtaining of new growth driver. In addition, in the existing urban transport system, ground transport requires a large amount of investment in land acquisition and relocation, and the use of low vacuum pipeline technology can effectively avoid or reduce the cost of it, securing better cost efficiency. The research, development and application of low vacuum pipeline technology will also promote the development of railway-related industries, enhance the ability of scientific and technological innovation, and form a benign environment of joint development with other enterprises.
