Megawatt Electric Motors With High Temperature Superconductors

Abstract

Superconducting materials opens up new possibilities for electrical machines. They can carry significantly higher current densities compared to traditional copper conductors. Consequently, much higher air-gap magnetic flux densities and current loads can potentially be created, but at the expense of a more complex cryogenic cooling system. This paper presents a study of the possibility of creating a 1 MW electric motor using superconductors for the stator winding. Designs with radial flux and axial flux has been considered. For the design with radial flux, an external rotor motor has been chosen as having the potential to achieve higher power densities. Further optimization of electric motors with an external rotor concerned changes with the geometry of the stator tooth zone and the use of other magnetic rotor systems. During optimization, a reduction in the mass of active materials and a reduction in torque ripple has been obtained in comparison with a standard design of an electric motor with radial magnetic flux. Calculations were also carried out using a copper winding in cryogen, which showed comparable results with the design of an electric motor with high-temperature superconductors.