This paper describes the construction and main components of a full-scale superconducting magnetic levitation vehicle. The prototype, comprising four 1.5-m-long wagons, will travel a short test line of 200 meters, connecting two buildings inside the campus of the Federal University of Rio de Janeiro. The efforts to implement this technology started thirteen years ago with a small-scale prototype in an attempt to prove the concept. The second step was the construction of a functional prototype that could levitate more than one Ton. The actual stage of this project is the construction of an operational prototype mentioned above, designed to transport up to 24 passengers. This work has been reported in several previous editions of the ASC conference. New details about the elevated test line, the permanent magnetic (Nd-Fe-B) guideways, the cryostats with YBCO high critical temperature superconductors, the energy conditioning, the linear induction motor and its regenerative braking, as well as the automatic supply system of liquid nitrogen will be presented in the proposed paper. Tests with this operational prototype demonstrate the technology feasibility.

The induction motor (IM) is a high-efficiency machine when working close to its rated operating point. However, at torques and/or speeds far from the rated values the efficiency is greatly reduced. In this work a new approach is proposed that minimizes the total copper and iron losses in a variable speed and/or torque IM drive, while keeping a good dynamic response. This method is based on a simple IM model that includes iron losses. The model, which only requires the knowledge of conventional IM parameters, is referred to a field-oriented frame. Using this model, the IM losses are quantified and an algorithm, based on a field-oriented scheme, is deduced. Simulation and experimental results are presented to validate the proposed method.<>

The Brazilian project MagLev-Cobra proposes a superconducting levitation vehicle for urban transportation in highly populated cities. The levitation technology is based on the diamagnetic behavior and flux pinning property of Y-Ba-Cu-O blocks in the proximity of the magnetic field of Nd-Fe-B magnets. The traction is given by a short primary linear induction motor. In previous editions of EUCAS conference, laboratory tests were presented to validate the levitation method and vehicle design. In this paper, recent operational results of the MagLev-Cobra traveling along an outdoor 200-m test facility constructed in the university campus will be reported. The full-scale vehicle is composed of four modules, interconnected by mechanical links. The transportation capacity is equivalent to 5 passengers/m ² , a limit of transportation comfort and quality. Acceleration, braking, and also cruising speed conditions were analyzed. A data acquisition system monitored the levitation gap and other parameters along the track. This effort is an important step to certificate the operational safety, an indispensable condition before industrialization and commercialization.

A full-scale MagLev vehicle prototype has been developed by the team of the Laboratory for Applied Superconductivity from the Federal University of Rio de Janeiro. This vehicle is named MagLev-Cobra (cobra means snake in Portuguese), because it is composed by several modules and its motion in curves resembles the movement of a snake. The suspension technology proposed for this vehicle is the levitation of bulk superconductors above a rail made with Nd-Fe-B magnets and steel. The main advantages of the MagLev-Cobra vehicle are low energy consumption, negligible noise emission, curvature radius of 45 meters and capability to ascend ramps of 15%. These properties allow the vehicle to be perfectly adjusted to big cities layout and to be constructed along roads and rivers. One of the most important parts of this project is the superconductor linear magnetic bearing (SLMB) development for the MagLev. In this work, some new results of the SLMB are presented. Measurements of the vertical levitation force of the SLMB and the effect of the flux creep on this force are presented. Also, some tests were made to investigate the influence of the load variation on the levitation force and the SLMB levitation gap. Finally, some tests were made to measure the levitation force and torque in the cryostat for an angular displacement between it and the magnetic guideway. These tests simulate the vehicle operation in real conditions.

This article describes the construction and operational advantages of a superconducting magnetically levitated (MagLev) vehicle in comparison with wheel-rail traditional options and applied to urban transportation. The technology was tested with a small-scale prototype. A comparison with other MagLev technologies is presented and application niches are identified. The steps for a full-scale implementation and commercialization will also be addressed.