How would superconducting motors/generators work?

[PhiowPhi]

How can superconductors improve motor/generator's performance?

A superconductor will expel a magnetic field, how can it generate a Lorentz force in the case of a motor, and a induced EMF in the case of a generator?

It's makes sense that we can only improve the windings of the electromagnet, to make it superconducting generating higher fields. But what about the rotor of a motor if it's a superconducting... having higher currents would lead to greater torques & speeds,due to the combination of a stronger field & higher current?

 

[anorlunda]

https://en.wikipedia.org/wiki/Superconducting_electric_machine

http://nextbigfuture.com/2009/01/365-megawatt-superconducting-motor.html

That has been thoroughly explored. Google returns many hits on superconducting motors.