A High-Temperature Superconducting Maglev-Evacuated Tube Transport (HTS Maglev-ETT) Test System

TLDR

Evacuated tube transport can drastically cut air friction, and adding maglev eliminates wheel‑rail friction, but integrating the two remains a major technical challenge. The authors built the first 45‑m high‑temperature superconducting maglev‑evacuated tube test system, the “Super‑Maglev,” to demonstrate this concept. The system comprises a 1‑t HTS maglev vehicle‑guideway coupling with a 10‑mm levitation gap, a 45‑m 2‑m‑diameter evacuated racetrack pumped by a hybrid air extraction system, and a 3‑m linear induction motor for propulsion. Under a tube pressure of 2.9 kPa, the prototype achieved a 50 km/h top speed, reduced air drag, and theoretically could cut aerodynamic power consumption by up to 90 %, confirming the feasibility of the HTS maglev‑ETT concept.

Abstract

As a bellwether transportation mode, albeit with hot controversy, evacuated tube transport (ETT) can dramatically reduce air friction, and incorporating Maglev technology could also thoroughly eliminate wheel-rail friction. It is not difficult to imagine that incorporation of these two technologies could establish an innovative transportation system, with particular advantages in terms of high speed, safety, energy saving, and environmental protection. The integration of these two technologies has been a great challenge, however, due to the composite technology. To realize this revolutionary idea, we have successfully developed the first proof-of-principle prototype of a 45-m-long high-temperature superconducting Maglev evacuated tube transport (HTS Maglev-ETT) test system, called the "Super-Maglev," based on the passive self-stable HTS Maglev conceived in our group in 2000. The system mainly consists of three parts: an HTS Maglev-vehicle-guideway coupling system with 1-t load capability at a levitation gap of 10 mm, a 45-m-long racetrack-type evacuated tube with a 2-m-diameter circular cross section pumped by a hybrid air extraction system, and a 3-m linear induction motor to provide sectional propulsion. The system can achieve a pressure as low as 2.9 kPa in the tube. Experiments show that air drag on the vehicle is greatly reduced at that low air pressure, and a maximum speed of 50 km/h was recorded on the 6-m-diameter test guideway. Theoretically, the reduction of the aerodynamic consumed power could reach as high as to 90% under 10 kPa. This "Super-Maglev" strongly demonstrates the feasibility and potential merits of the HTS Maglev-ETT transportation concept.