The application of superconductors in electric motors has been much studied for technical, economic reasons, and for reducing energy wastage.
The scientific studies for the use of new materials aim at reducing the costs, the weight and the dimensions of the machines by the application of magnetic fields larger than the conventional ones, since the commercial superconducting wires allow to have density of current much higher to the one used by the copper, Of the order of 15 to 20A / mm2.
This density may appear low when compared to the current density of the superconductor itself, which currently reaches 500A / mm2, but unfortunately this immense density can not yet be fully exploited. This superconducting material still needs a mechanical holding precursor, such as a silver coating.
As for the number of poles in electric motors with superconductors, the magnetomotive force is not very influenced by the number of poles, but the greater number of poles the greater the superconducting material, and its cost. We can conclude that the lower the number of poles, the better it will be, since the volume of the superconductor will be smaller, besides having fewer connections.