A superconducting machine for Aircraft application
Résumé
The use of electric motors or generators for aircraft application requires fewer prime movers and auxiliary equipment than conventional propulsion systems. Thus, the performance in terms of efficiency, reliability are improved. However, the dynamic behavior of an aircraft required motor which transmit high speed on the propellers. The challenge is to develop an axial-field superconducting motor or a generator with high power density, up to 10 kg/kW.
The inductor is composed of one superconducting solenoid made with YBCO tape separated by an YBCO superconducting plates. The solenoid is fed by a direct current and produce a magnetic field in the axial direction. The diamagnetic behavior of a superconducting bulk cooled under zero-field is used to obtain a variation of the magnetic flux density in the air-gap. This kind of inductor is original.
The stator consists of a classical 3-phase windings made with copper without iron teeth in order to improve the performance. The armature windings is water cooled which permit a large increase for the current density. Moreover to be competitive in term of power density, the design of the machine is made without any ferromagnetic materials. This new kind of superconducting motor have been designed by 3D finite element computations.
In this paper, we will present a specific design for this superconducting machine with a nominal power of 200 kW and a speed of 5000 rpm, taking into account the cooling system. Some technical issues will be discussed as the way to give the particular shape of the YBCO plates.