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One electromagnetic launcher structure is proposed based on the principle of a permanent-magnet synchronous motor. Without additional levitation structures adopted, the magnetic levitation of the mover is realized by the current vector control, i.e., the stator excitation currents are controlled to generate two force components in the d-q coordinate system; the q-axis component is the propulsive or attractive force for the launching, while the d-axis component is used to levitate the mover at one stable position. The structure, design, and control of the proposed launcher are discussed based on the analysis. Index Terms--Brushless dc motors, component, electromagnetic launching (EML), magnetic levitation, vector control.

Numerical simulation of the superconducting magnetically levitated bogie (JR Maglev) has been studied. Electrodynamic suspension is used for levitation and guidance. Although this suspension needs no gap control, damping factor of the system is shown to be small. Therefore additional damping system is considered. The passive and the active damper coil system are introduced to increase damping of the levitation system. Running simulation of the bogie when the train accelerates is undertaken. The passive damper coil decreases oscillation of the bogie. Although the active damper system shows larger effect, it needs much electric power. The passive damper coil shows enough damping factor in case of normal acceleration. Index Terms--Active damper, electrodynamic suspension, magnetic levitation, superconducting.

In common active magnetic levitation systems, a floating object is controlled stably by an electromagnet with a narrow air-gap, which reduces the leakage flux. However, in order to move a floating object dynamically, it is necessary to arrange electromagnets for horizontal motion and to make the air-gap wide for vertical motion at the expense of leakage flux. In this paper, we propose a novel magnetic levitation system having a compact electromagnet composed of four I-shaped electromagnets. We report constructional features, control techniques, and three-dimensional motion of the floating object. Index Terms--Bias-magnetic force, electromagnetic forces, magnetic levitation, permanent magnets, position control.

A linearized model of active magnetic bearings (AMBs) is normally used for determining the settings of decentralized PID controllers, which are used in industrial applications. Parameters of the linearized model, i.e., current gain and position stiffness, are defined for the nominal operating point and, thus, vary according to the operating point. These variations are analyzed by the finite element (FE) computation. The obtained results show considerable variations for the discussed parameters. Therefore, AMB geometry is numerically optimized, using differential evolution in combination with FE computation. The optimization objective is a minimal variation of the current gain, and position stiffness. The optimized AMBs shows good properties according to the linearized model over the entire operating range. In this way, the robustness of the closed-loop controlled AMB system is increased. Index Terms--Magnetic levitation, numerical analysis, parameter estimation, robustness.

A high-[T.sub.C] superconducting (HTS) magnetic levitation (Maglev) system consisted of bulk superconductors and T-shaped permanent magnet single-guideway is examined for HTS Maglev vehicle. The results have shown that the system with T-shaped permanent magnetic guideway has generated large guidance force and good stability that are helpful for the further HTS Maglev vehicle.

The development of different Maglev systems, their application for passenger transportation and the promotion of the Maglev transportation in China are described. The studies have shown that the Maglev has many advantages for fast passenger transportation and they are already matured for practical application due to continuous development.

The interaction energy and levitation force between a thin monolayer of ferromagnetic particles on a surface of a large superconductor in Meissner state are examined. The interaction energy and the levitation force increases as the temperature of the monolayer increases.

The gap between a superconductor and a permanent magnet varying with time in high-[T.sub.c] superconducting levitation system is studied. The results show that the drift velocity is dependent upon properties of superconductivity, initial disturbances, and applied excitations.

An analytical model is used for evaluating the torque on a superconducting magnetically-supported spinning sphere resulted from aspheric factors. Findings reveal that the torque caused by the maximum centrifugal distortion vanishes when the cover range of the coil is [pie]/2.

The design of a magnetically levitated superconducting conveyer for wafer transportation is discussed. Findings reveal that the usage of proportional and differential control suppresses the vibrations of displacement.

Two levitational configurations for the superconducting launch ring concept are examined. Results suggest that both the attractive and shear-force configurations are capable of complete static stability over the complete velocity range from 0 to 10 km/s.