Search

High-speed, fully superconducting electric rotating machines are highly sought for naval and aerospace applications, to provide significantly higher power density than can be achieved by other means. We examined the use of an MgB2 -based, two-stage, cabled conductor for the armature winding of a medium power (10–15 MW) electric generator, operating near 20 K at a nominal peak phase current of 2 kA. We chose MgB2 because it is electromagnetically isotropic and can be manufactured as round, multifilamentary strands. This paper describes the proposed conductor and presents our prototype manufacturing efforts. Prototype cables were fabricated using fine filament (15-μm filament diameter) strand manufactured by Hyper Tech Research. AC losses in MgB2 triplet bundles were measured at 20 K using a calorimetric technique. We present measured AC loss data for the MgB2 triplets and evaluate those losses in relation to the strand composition and strand and cable configurations. [ABSTRACT FROM PUBLISHER]

Superconducting synchronous machines require Direct Current (DC) excitation for their field windings which can be achieved via brushless exciters or by direct connection to current leads. However, the resulting heat loads limit their application. An excitation system consisting of a High-temperature Superconducting (HTS) full wave rectified flux pump eliminates these issues and enables operation at high currents. [ABSTRACT FROM AUTHOR]

This article introduces a new conceptual design tool for an environmentally sustainable method of aeropropulsion: a ducted fan system driven by a fully superconducting electrical machine. Such a system could help mitigate aviation's contribution to global climate change by enabling the reduction of greenhouse gas emissions from aircraft. An electro-thermal motor sizing model was coupled with cycle analysis and weight estimation routines to create an automated environment for rapid design trade studies. The resulting parametric cycle analysis and sizing outcomes revealed the system's operational boundaries for a given aspiration space. [ABSTRACT FROM AUTHOR]

This paper describes the design of a new kind HTS motor. Superconducting plates used as magnetic screen that cause a spatial variation of the flux density. It is theoretically possible to obtain an air gap flux density variation greater than 3 T. We perform a dimensionless study of the device showing that the torque depends on shape parameters and is limited by the maximum field on the superconducting wire. In the last section, we discuss the performance of the device in term of torque density. [ABSTRACT FROM AUTHOR]

Electrical motors need a spatial variation of the flux density created by their inductors to make torque. We propose to achieve this angular repartition of the induction with bulk high temperature superconducting plates and two low temperature superconducting solenoids. These solenoids have the same axis and are fed with opposite currents in order to create a radial magnetic induction. Four superconducting plates placed on the cylindrical surface, situated on the same axis and having the same radius as the solenoids, concentrate the magnetic field. This device provides a spatial variation of the flux density, and can be considered as an inductor for a synchronous motor with eight poles. This paper presents the experimental study of our prototype at 4.2 K. We compare the experimental results with calculation. Ten hall probes permit us to reconstitute the angular variation of the flux density. The paper shows the feasibility of this new kind of superconducting inductor. [ABSTRACT FROM AUTHOR]