Superconducting Electromagnetic Suspension (EMS) system for Grumman Maglev concept

The Grumman developed Electromagnetic Suspension (EMS) Maglev system has the following key characteristics: a large operating airgap--40 mm; levitation at all speeds; both high speed and low speed applications; no deleterious effects on SC coils at low vehicle speeds; low magnetic field at the SC coil--less than 0.35 T; no need to use non-magnetic/non-metallic rebar in the guideway structure; low magnetic field in passenger cabin--approximately 1 G; low forces on the SC coil; employs state-of-the-art NbTi wire; no need for an active magnet quench protection system; and lower weight than a magnet system with copper coils. The EMS Maglev described in this paper does not require development of any new technologies. The system could be built with the existing SC magnet technology

Transient phenomena in large induction motors in a power system

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Octopole design concepts for the mirror end cell

This paper describes the scoping design study of the saddle coil winding and its support structure. The support concept for interconnecting the four saddle coils (to form the octopole) is described. An octopole consisting of saddle coils can be fabricated using current conductors and coil winding technology

Superconducting AC Homopolar Machines for High-Speed Applications

This paper presents a novel high-speed alternating current (AC) homopolar motor/generator design using stationary ReBCO excitation windings. Compact, lightweight, high-efficiency motors and generators are sought for a multitude of applications. AC homopolar synchronous machines are an ideal choice for such applications as these machines enable very high rotational frequencies. These machines include both AC armature winding and direct current (DC) excitation winding within the stationary part of the machine. The stationary excitation winding magnetizes a solid steel rotor, enabling operating speeds limited only by the mechanical stress limit of the rotor steel. The operating speeds are many multiples of conventional power 50/60 Hz machines. Significant cooling requirements limit machines of this type utilizing copper excitation windings to only a few kilowatts. However, megawatt ratings become possible when superconductor coils are used. This paper describes the design and analysis of an AC homopolar machine in the context of developing a 500 kW flywheel system to be used for energy recovery and storage in commuter rail subway systems. Different approaches are discussed for an AC armature employing conventional copper coils. Challenges of building and cooling both armature and field coils are discussed and preferred approaches are suggested. Calculations of the machine performance are then made

AC Loss Simulation in HTS Armature Windings of A 100 kW All-HTS Motor

International audienceAn all-HTS motor is a promising device that can provide more compact size and higher performance than conventional motors. However, high AC loss in the HTS armature windings requires large cryogenic system which makes all-HTS motors impractical. This work numerically studied AC loss behaviours of the HTS armature windings in a 100 kW, 1500 rpm HTS motor. The model is based on COMSOL Multiphysics and T-A formulation. In order to investigate the real time electromagnetic behaviours, the moving mesh and rotating machinery interface are applied in this model. Preliminary results on magnetic flux distribution in the whole motor, current density in the HTS armature windings as well the AC loss are presented

AC Loss Simulation in HTS Armature Windings of A 100 kW All-HTS Motor

International audienceAn all-HTS motor is a promising device that can provide more compact size and higher performance than conventional motors. However, high AC loss in the HTS armature windings requires large cryogenic system which makes all-HTS motors impractical. This work numerically studied AC loss behaviours of the HTS armature windings in a 100 kW, 1500 rpm HTS motor. The model is based on COMSOL Multiphysics and T-A formulation. In order to investigate the real time electromagnetic behaviours, the moving mesh and rotating machinery interface are applied in this model. Preliminary results on magnetic flux distribution in the whole motor, current density in the HTS armature windings as well the AC loss are presented