Maglev

Abstract: The first man-loading high temperature superconducting Maglev test vehicle in the world is reported. This vehicle was first tested successfully on December 31, 2000 in the Applied Superconductivity Laboratory, Southwest Jiaotong University, China. Heretofore over 17,000 passengers took the vehicle, and it operates very well from beginning to now. The function of suspension is separated from one of propulsion. The high temperature superconducting Maglev provides inherent stable forces both in the levitation and in the guidance direction. The vehicle is 3.5 m long, 1.2 m wide, and 0.8 m high. When five people stand on vehicle and the total weight is 530 kg, the net levitation gap is more than 20 mm. The whole vehicle system includes three parts, vehicle body, guideway and controlling system. The high temperature superconducting Maglev equipment on board is the most important for the system. The onboard superconductors are melt-textured YBaCuO bulks. The superconductors are fixed on the bottom of liquid nitrogen vessels and cooled by liquid nitrogen. The guideway consists of two parallel permanent magnetic tracks, whose surface concentrating magnetic field is up to 1.2 T. The guideway is 15.5 m long.

Abstract: This paper describes the present status of high temperature superconductors (HTS) and of bulk superconducting magnet devices, their use in bearings, in flywheel energy storage systems (FESS) and linear transport magnetic levitation (Maglev) systems. We report and review the concepts of multi-seeded REBCO bulk superconductor fabrication. The multi-grain bulks increase the averaged trapped magnetic flux density up to 40% compared to single-grain assembly in large-scale applications. HTS magnetic bearings with permanent magnet (PM) excitation were studied and scaled up to maximum forces of 10 kN axially and 4.5 kN radially. We examine the technology of the high-gradient magnetic bearing concept and verify it experimentally. A large HTS bearing is tested for stabilizing a 600 kg rotor of a 5 kWh/250 kW flywheel system. The flywheel rotor tests show the requirement for additional damping. Our compact flywheel system is compared with similar HTS–FESS projects. A small-scale compact YBCO bearing with in situ Stirling cryocooler is constructed and investigated for mobile applications. Next we show a successfully developed modular linear Maglev system for magnetic train operation. Each module levitates 0.25t at 10 mm distance during one-day operation without refilling LN2. More than 30 vacuum cryostats containing multi-seeded YBCO blocks are fabricated and are tested now in Germany, China and Brazil.

Abstract: In this paper, we present a high-precision magnetic levitation (maglev) stage for photolithography in semiconductor manufacturing. This stage is the world’s first maglev stage that provides fine six-degree-of-freedom motion controls and realizes large (50 mm × 50 mm) planar motions with only a single magnetically levitated moving part. The key element of this stage is a linear motor capable of providing forces in both suspension and translation without contact. The advantage of such a stage is that the mechanical design is far simpler than competing conventional approaches and, thus, promises faster dynamic response and higher mechanical reliability. The stage operates with a positioning noise as low as 5 nm rms in x and y , and acceleration capabilities in excess of 1 g (10 m/s 2 ). We demonstrate the utility of this stage for next-generation photolithography or in other high-precision motion control applications.

Abstract: Topology and Selection Definitions, Geometry, and Thrust Generation Linear Synchronous Motor Topologies Calculation of Forces Linear Motion Selection of Linear Motors Materials and Construction Materials Laminated Ferromagnetic Cores Permanent Magnets Conductors Principles of Superconductivity Laminated Stacks Armature Windings of Slotted Cores Slotless Armature Systems Electromagnetic Excitation Systems Superconducting Excitation Systems Hybrid Linear Stepping Motors Theory of Linear Synchronous Motors Permanent Magnet Synchronous Motors Motors with Superconducting Excitation Coils Variable Reluctance Motors Permanent Magnet Hybrid Motors Motion Control Control of AC Motors EMF and Thrust of PM Synchronous and Brushless Motors Dynamic Model of a PM Motor Thrust and Speed Control of PM Motors Control of Hybrid Stepping Motors Precision Linear Positioning Sensors Linear Optical Sensors Linear magnetic Encoders High Speed Maglev Transport Electromagnetic and Electrodynamic Levitation Transrapid System (Germany) Yamanashi Maglev Test Line in Japan Swissmetro Marine Express Building and Factory Transportation Systems Elevator Hoisting Machines Ropeless Elevators Assessment of Hoist Performance Horizontal Transportation systems Industrial Automation Systems Automation of Manufacturing Processes Casting Processes Machining Processes Welding and Thermal Cutting Surface Treatment and Finishing Material Handling Testing Industrial Laser Applications Appendix A Magnetic Circuits with Permanent Magnets Appendix B Permeances for Magnetic Fluxes Appendix C Performance Calculations for PM LSMs Symbols and Abbreviations References